■ rc ^^^H 8Z4 ^^^H CZ p^^H AZ Suiitol'. ' ^^^^1 ho. /34-:iZ UBRARY uis..vt.K.siTY0FCAUFORVT^ nAvr<; THE RESOURCES AGENCY OF CALIFORNIA partment of Water Resources BULLETIN No. 134-62 SALINE WATER CONVERSION ACTIVITIES IN CALIFORNIA AUGUST 1963 UNIVERSITY OF CALIKORNIA DAVIS MAR 1 8 1965 1 IRRARY 1 HUGO FISHER Administrafor The Resources Agency of California EDMUND G. BROWN Governor State of California WILLIAM E. WARNE Director Department of Water Resources state ot Cdiifornia THE RESOURCES AGENCY OF CALIFORNIA Department of Water Resources BULLETIN No. 134-62 SALINE WATER CONVERSION ACTIVITIES IN CALIFORNIA AUGUST 1963 HUGO FISHER EDMUND G. BROWN WILLIAM E. WARNE Administrafor Governor Direcfor The Resources Agency of California State of California Department of Water Resources TABLE OF CONTENTS Page LETTER OF TRANSMITTAL vll ORGANIZATION, DEPARTMENT OF WATER RESOURCES vlli PART I. CONVERSION ACTIVITIES OF THE DEPARTMENT OF WATER RESOURCES INTRODUCTION 1 GENERAL PROGRAM 2 INVESTIGATIONS 3 The San Diego Demonstration Plant ^ San Joaquin Valley Drain 8 Salton Sea State Park 12 Economics of Conversion 20 Electrodialysis 20 Distillation 23 Nuclear Energy 25 Solar Energy 27 Survey of Brackish Water Areas 27 PART II. OTHER CONVERSION ACTIVITIES WITHIN CALIFORNIA A. UNIVERSITY OF CALIFORNIA INTRODUCTION 35 REPORTS o . . . . 36 PROJECTS 38 Electrodialysis 38 Carryover Studies 38 Scale Studies 38 lli Page Ion Exchange 39 Direct Contact Heat Transfer 39 Freeze-Separation 39 Thermodynamic Studies 39 Solar Distillation Studies 39 Multiple Effect Rotating Still .... 39 Capillary Control of Vapor Transfer Gap 40 Pilot Plant Development 40 Demlnerallzatlpn by Means of a Semipermeable Membrane 40 Techniques of Optimization 40 Transport Phenomena Near a Liquid Vapor Interface 4l Experimental Heat Transfer Studies . , 4l Waste Water Reclamation Biological Systems 41 Corrosion Studies 4l B. OTHER AGENCIES COALINGA 42 OFFICE OF SALINE WATER 44 Demonstration Plant 44 Research and Development 47 Aerojet -General Corporation ... ^8 Bechtel Corporation 48 FMC Corporation 49 iv Page Ford Motor Company 50 General Dynamics Corporation ... 51 Leslie Salt Company 52 Narmco Research & Development ... 52 Stanford Research Institute ... 53 University of California 54 Western Independent Research Laboratories 55 UNITED STATES NAVY 55 PRIVATE COMPANIES 56 Pacific Gas & Electric Company .... 57 Southern California Edison Company . , 58 North American Aviation 58 Havens Industries 60 TABLES Table No . 1. San Joaquin Valley Drainage Water - Quality and Quantity 9 2. Typical Water Quality of San Joaquin Valley Drainage Water 11 3. Composition of Salton Sea and Pacific Ocean Water , 15 4. Estimated Capital Cost of Conversion Plants at Salton Sea State Park 17 5. Current Sea and Brackish Water Conversion Cost Estimates 21 Page 6. Basic Data on Areas In Southern California for Possible Sites for Saline Water Conversion Plants 29 7. Reports Issued during I962 by University of California Water Resources Center, Sea Water Conversion Program 37 8. Report of Chemical Analysis of Coallnga Water . . 43 9. Office of Saline Water Research and Development Progress Reports 45 Figure No . FIGURES 1. Schematic Flow Diagram of the Multistage Flash Evaporation Process at San Diego, California . . 6 2. Location of Proposed Conversion Plants at Salton Sea 16 APPENDIXES APPENDIX A - Conversion Activities Outside California . . A-1 APPENDIX B - Application of Solar Energy to Conversion in California B-1 APPENDIX C - Bibliography C-1 vl WILLIAM E. WARNE Director of Wat«r Rftsources B. ABBOn GOLDBERG Chief Deputy Director REGINALD C. PRICE Deputy Director Policy NEELY GARDNER Deputy Director Aaministrotion ALFRED R. GOLZE Chief Engineer EDMUND G. BROWN GOVERNOR OF CALIFORNIA HUGO FISHER ADMINISTRATOR RESOURCES AGENCY ADDRESS REPLY TO P. O. Box 388 Sccrcmento 2, Calif, THE RESOURCES AGENCY OF CALIFORNIA DEPARTMENT OF WATER RESOURCES J 120 N STREET, SACRAMENTO June 17, 1963 Honorable Edmund G. Brown, Governor and Members of the Legislature of the State of California Gentlemen: I have the honor to transmit herewith Bulletin No. 134-62, of the State Department of Water Resources, entitled "Saline Water Conversion Activities in California," The report finds that, in general, no single purpose conversion process can now compete with the cost of large- scale development of natural sources of water in California. Under certain conditions conversion plants, combined with power generation, may become economically attractive within the foreseeable future. The economic potential of the conversion of brack- ish water and waste water renovation is comparatively more promising than conversion of more saline sources. The research and development work now in progress by other agencies and private enterprise within the State on conversion of sea water, brackish water, and waste water are described in this bulletin. Activities in the field outside California are also briefly described. Sincerely yours. f.U^^ Director vil STATE OF CALIFORNIA THE RESOURCES AGENCY OF CALIFORNIA DEPARTMENT OF WATER RESOURCES EDMUND G. BROWN, Governor HUGO FISHER, Administrator, The Resources Agency of California WILLIAM E. WARNE, Director, Department of Water Resources ALFRED R. GOLZE, Chief Engineer DIVISION OF RESOURCES PLANNING WILLIAM L. BERRY Division Engineer MEYER KRAMSKY Chief, Statewide Investigations Branch RALPH G. ALLISON .... Chief, Planning Investigations Section The preparation of this report was conducted under the direction of: MAURICE B. ANDREW Supervisor, Applied Nuclear and Saline Water Conversion Unit BY DONAT B. BRICE Staff Chemical Engineer viii PART I. CONVERSION ACTIVITIIS OF THE DEPARTMENT OF WATER RESOURCES INTRODUCTION The primary objective of the department's program In conversion is its application to the development of water resources that are otherwise unsuitable for the intended application. Such waters Include sea and brackish water, which normally contain primarily inorganic contaminants, and treated waste waters which contain both organic and Inorganic contaminants. When the dissolved contaminants are removed from such waters, they may then be considered as alternative sources of supply. The actual use may be for domestic, industrial, or agri- cultural applications, or for replenishment of ground water, de- pending on the treatment provided and dissolved contaminants removed. For any given application for the conversion of water, the matter. of economics is of overriding concern, since a choice may usually be made from among a number of alternative water supplies. However, economics is closely related to techniques; therefore, both technological advancements and the related eco- nomics are of prime interest to the department. Part II of the bulletin discusses conversion activ- ities within California by other agencies and private companies. Appendix A describes some of the highlights of conversion throughout the world. -1- GENERAL PROGRAM The application of conversion, whenever feasible, to the further development of the State's water resources and the advancement of the technology and economics of conversion are the chief objectives in this program of the department. Currently, consideration is being given to the appli- cation of conversion techniques as part of the overall study of the San Joaquin Valley Drainage investigation. Increased attention is being given to the removal of organic contaminants from waste water. The particular contami- nants are those that are not degraded by the usual waste water treatment plants. Such materials are termed refractory. Consideration is being given to improvement in quality of ground and surface water supplies by removal of dissolved materials in areas within the State where total dissolved solids are above 1,000 ppm or appear to be increasing as more intensive use is made of the water supplies. It is also planned to evalu- ate the potential of conversion in the long-range planning of the department. Because such plans extend for a long time into the future, it is prudent to evaluate the role conversion may play in such plans. Activities of the department in conversion in carrying out the above-mentioned objectives and discharging its responsi- bility as technical advisor to the Legislature and to water agencies, include the following: -2- 1. To keep thoroughly Informed on existing and potential conversion processes and advanced waste water renovation processes. 2. To associate and cooperate with other public and private agencies involved in problems of the removal of dissolved materials from water. 3. To collect and analyze technical and cost data on conversion and renovation plants now in operation or being constructed, including demonstration and pilot plants. 4. To investigate and plan in specific areas for the application of processes capable of removing con- taminants from water sources. 5. To advise communities on the applicability of conversion processes to their water supply problems. 6. To keep the public informed on conversion appli- cations. 7. To evaluate potential demonstration or experi- mental conversion plant installations either as co- operative projects with other public agencies, or independently. INVESTIGATIONS Studies of the application of conversion as an alter- native water supply or quality improvement were made for the -3- Salton Sea area and in the San Joaquin Valley. The major effort the previous year was with the construction of the San Diego sea water conversion plant. This effort was continued during the early part of 19^2, at which time the performance test was being followed closely. Also, the department's engineer remained at the site to observe the initial operation of the plant during the first half of the year. The details of the several investigations undertaken In conversion by the department are discussed in this section of the bulletin. In addition, indications of feasibility of application under various conditions and situations are discussed. The San Diego Demonstration Plant The department has cooperated both technically and financially with the Office of Saline Water (OSW) on the con- struction of the one million gallons per day multistage flash evaporator demonstration plant. The plant is located on Point Loma near San Diego. During the construction phase in I961 the department devoted considerable effort to the plant. In addition to having a resident engineer at the site during the construction, the de- partment checked the construction drawings and calculations of the contractor and made appropriate comments thereon to the OSW. After the plant construction was completed in November 1961, the construction contractor devoted the early part of 1962 -4- to the operation of the plant. During this period the mechanical features were checked under operating conditions and the plant was prepared for the performance test required as part of the con- struction contract. The department participated in these activi- ties and kept an engineer at the site during the first half of 1962 to observe this performance. The operation and design of the plant has been previously- described (1,2,3,^).* A brief description is included in this bulletin. In addition, a schematic flow diagram of the process, with some typical operating conditions is shown in Figure 1. In this process, the sea water is pumped through the tubes of the 36th and 35th evaporator stages and the air ejector condenser before being introduced into the deaerator, which is connected to the shellside of the 36th stage. The 36th stage is the lowest pressure and temperature stage. Before the sea water is introduced into the deaerator, the excess which is required for cooling. is discharged back into the ocean. The remainder is treated with chemicals for scale prevention before it is intro- duced into the deaerator. The deaerated sea water serves as a make-up to the plant. It is mixed in the shellside of the 36th stage with the brine before the two streams are pumped from the stage. The excess brine is also pumped from this stage and returned to the ocean. ^Refers to Bibliography - Appendix C. -5- FIGURE 1 SCHEMATIC FLOW DIAGRAM OF THE MULTISTAGE FLASH EVAPORATION PROCESS AT SAN DIEGO, CALIFORNIA (TYPICAL OPERATING CONDITIONS) Noncondensable gases Low pressure steam from pumps & boiler Legend - A Recycle No. 1 --■ -- B Recycle No. 2 -_. ,-. ._ ^ Flashing brine No. 1 - D Flashing brine No. 2 Sea water inlet (3.5% NoCI) 1,300,000 Ib./hr. Blowdown (5.2% NaCI) 354,000 Ib./hr. Product water 80 F. to City of San Diego 1^354,000 Ib./hr. -6- The combined brine and make-up constitute the recycle stream that Is pumped through the tubes of the evaporators from stage 3^ to stage 1 and the brine heater. In the brine heater steam Is used to heat the brine to the desired temperature. The heated brine Is then Introduced Into the shellslde of the first stage, which Is the highest tempera- ture stage. The flashing process starts in this stage. The brine then flows from stage to stage. Each succeeding stage is maintained at a lower pressure than the previous stage. A quan- tity of vapor sufficient to cool the brine to the temperature in equilibrium with the stage pressure is flashed in each stage. When the brine reaches the 36th stage, as previously described, it is either recycled through the evaporators or discharged into the ocean. The condensate which is condensed in each stage is caught in a trough and flows through the evaporators until it reaches the 36th stage. It also flashes in each stage sufflcently to cool it to the temperature in equilibrium with the pressure in the stage. It is pumped from the 36th stage to a cooling tower where the product is cooled to SO^F. before it is delivered to San Diego's treatment and pumping facility. Additional Information about the operation of this plant by the Office of Saline Water is given in Part II of this bulletin. -7- San Joaquin Valley Drain The need for disposal of agricultural drainage water In major portions of the San Joaquin Valley through the San Joaquin Valley Drainage Facilities, Is under Intensive study by the department. The economic potential of the partial removal of dissolved material from the drainage water by electrodlalysls, biological means, or other processes. Is under study as part of this Investigation (5). Because of the diverse nature of the material expected In the drainage water, a study Is planned to evaluate the several conversion processes and to define areas where additional Infor- mation may be required before conversion cost estimates can be finalized. Preliminary estimates of conversion utilizing the electrodlalysls process, based on both current technology and upon projected technological Improvements by the time the drainage canal Is In operation, have been made In an exploratory manner. The quantity of water that will require disposal by decade has previously been reported (5). Table 1 gives the quantity by decade of drainage water that will require disposal; also Included in the table is the approximate average total dis- solved solids of the drainage effluent,. As can be seen, a sub- stantial amount of water would require treatment if conversion were to be used. The total dissolved solids are fairly high for -8- TABLE 1 SAN JOAQUIN VALLEY DRAINAGE WATER QUALITY AND QUANTITY Decade Acre-feet per Decade, Thousands Approximate Total , Dissolved Solids, ppm- / 1960-1969 2,281 8,200 1970-1979 2,576 4,700 1980-1989 2,591 5,300 1990-1999?/ 2,483 4,400 2000-2009^ 1,979 3,500 2010-2019^ 1,488 3,100 -/Parts per million parts of water. _y Based on estimated irrigated acreage for the average of the 1990-1999 decade. -9- the initial ten-year period. However, the total dissolved solids falls rapidly and for a considerable number of years will average about 4,500 ppm of salts. There are some tile drain effluents presently operating in the San Joaquin Valley. Based on these effluents, a typical analysis was developed for the exploratory study. The analysis is given in Table 2. With the exception of the boron, the composition is not unusual for a brackish water containing this amount of total dissolved solids. As the total salinity is either increased or de- creased, there will be a proportionate change in the ions present. More complete analyses are being developed from which a more de- tailed economic analysis of conversion of the drainage water by the electrodialysis process will be made during the coming year. With the present technology of the electrodialysis process, it is estimated that the salinity can be reduced from about 6,500 ppm to 1,600 ppm, thereby making the effluent suitable for reuse by agriculture for $195 per acre-foot. This cost includes amorti- zation, operation, and maintenance costs. The operating and main- tenance costs amount to over 80 percent of the total. The cost of reducing the salinity to potable water is about $235 per acre-foot. As shown in Table 1, it is anticipated that the salinity will ultimately be reduced to 3*100 ppm. The costs of making this water suitable for agricultural reuse will be about $105 per acre- foot, based on current technology. -10-. TABLE 2 TYPICAL WATER QUALITY OF SAN JOAQUIN VALLEY DRAINAGE WATER (I [ Based on tile drain effluents ) Constituent Amount, ppmJ :/ Calcium (Ca) 320 Magnesium (Mg) 250 Sodium (Na) 1,800 Potassium (K) 4 Bicarbonate (HCO3) 250 Sulfate (SO4) 2,800 Chloride (Cl) 1,100 Boron (B) 24 Silica (SIO2) 32 Nitrate 6 -^ Parts per million parts of water -11- It is anticipated that technological improvements in the electrodialysls process within the next few years will reduce the conversion costs cited above by a factor of two. Consequently, by the time the drainage canal is in operation, or shortly there- after, it may be possible to remove solids from the drainage water, based on the initial condition of salinity for about $100 per acre-foot, and based on the equilibrium salinity for about $50 per acre-foot. Since the salinity rapidly decreases during the second decade, it can be anticipated that further reduction in the costs of conversion will be possible by the time the sa- linity reaches the 4,500-5,000 range. Also, it is expected it will be possible to operate electrodialysls stacks with consider- ably higher salinity concentration in the brine discharge than is currently practiced. This would permit a reduction of the volume of highly saline water to a level that could be more easily dis- posed of either by ponding or by pumping by pipeline to the ocean. Additional work is planned during the next year on the application of techniques of conversion, not only electrodialysls, but other potential conversion processes, to the disposal of the agricultural drainage water. Salton Sea State Park At the request of the Department of Parks and Recreation, the department undertook a study of the alternative water supplies available to the Salton Creek area of the Salton Sea State Park. -12- A report by the department titled "Investigation of Sources of Water Supply for Salton Sea State Park" was made to the Depart- ment of Parks and Recreation. Conversion of water of the Salton Sea was considered as one of four alternative sources. The four plans and the esti- mated water costs from each are as follows: Plan Cost. $/acre-foot Salton Sea Water District (area method) 355 State-owned well 450 Coachella Valley Co. Water District 485 Salton Sea Water Conversion 580 As can be seen, the estimated cost of water from the newly-formed Salton Sea Water District was substantially less than the other three alternatives. The Department of Parks and Recreation has requested funds for fiscal year I963-64 to obtain water for the park from the Salton Sea Water District. Actually, conversion compared rather favorably with the other two alternatives. The unusual water demand curve at the park placed the state-owned well and the saline water conversion alternative at a distinct disadvantage because of their higher capital cost. This particular study was of interest because the conversion of water from the Salton Sea probably offers as great a challenge to a conversion process as any saline water source in -13- the State. It is considered encouraging that converted water compared as favorably as It did with the other alternatives. The composition of this highly saline water is given in Table 3. For comparison, the composition of the Pacific Ocean is also given in Table 3. Because it was intended to use the water at several locations along the east side of the Salton Sea, three 100,000 gpd multistage flash distillation plants were assumed for the analysis. One each would be located at Mecca Beach, Salt Creek Beach, and Bombay Beach. The distribution system to convey and regulate the converted water would require a 250,000 gallon tank and a 15-horsepower booster pumping plant at each of the three park developments. Also, about 700 feet of 4-inch diameter pipe- line would be needed at each development between the conversion plants and the tanks. The general locations of the facilities are shown in Figure 2. The total capital investment required is estimated to be $944,000. This cost breakdown is shown in Table 4. The life of mechanical items of the conversion plant is estimated to be 25 years and, therefore, require replacement during the amortization period of fifty years. The capital cost of the other items of the conversion plant were amortized over a fifty-year period in order to be compatible with the estimates made for the other alternative supplies. -14- TABLE 3 . COMPOSITION OF S ALTON SEA AND PACIFIC OCEAN WATER ( Values expressed In parts per million parts of water ) Salton Sea-/ Pacific Ra Ocean-^ Constituent May 1961 10,000 Sept. 1961 9,680 nge Sodium (Na) 10,052 - 10,444 Magnesium (Mg) 967 1,118 1,211 - 1,259 Calcixim (Ca) 800 790 381 396 Potassium (K) 172 140 362 376 Chloride (Cl) 14 ,300 14,600 18,074 - 18,779 Sulfate (SO4) 7 ,320 7,349 2,522 - 2,620 Bicarbonate (HCO3) 195 187 133 138 Fluoride (F) 3 3 1 1 Boron (b) 7.2 7.5 4.4 4.6 Bromide (Br) _ .. 62 64 y Analysis by Department of Water Resources - sampled at Salton Sea State Park. — / Calculated from chlorinlty measurements of samples taken at Scripps Institution of Oceanography pier. 48-year average, -15- FIGURE 2 LOCATION OF PROPOSED SALINE WATER CONVERSION PLANTS (SALTON SEA STATE PARK) SALT CREEK 250,000 Gallons BOMBAY BEACH LEGEND PIPELINE O RESERVOIR X PUMP CZD CONVERSION PLANT -16- TABLE 4. ESTIMATED CAPITAL COST OF CONVERSION PLANTS AT S ALTON SEA STATE PARK Item Capital Cost Saline water conversion plants, three 100,000-gallon3 per day capacity $ 625,000 Pipelines 10,000 Three pumping plants, 100 gpm 10,000 Three tanks, 250,000 gallons each 54,000 Subtotal: $ 699,000 Administration and engineering, 10^ 70,000 Contingencies, 25^ 175,000 $ 944,000 -17- The process selected for the analysis was a multistage flash evaporator similar to the sea water demonstration plant which is now operating in San Diego, and has previously been des- cribed in this bulletin. The Salton Sea area is one of relatively high-fuel cost. One of the most likely sources of fuel available for the operation of a distillation plant in that area is fuel oil delivered from the Los Angeles area. It is estimated that the cost of delivered fuel oil would be equivalent to 50-55 cents per million Btu. Because of this relatively high fuel cost, the performance ratio, i.e., the pounds of water produced per pound of steam condensed, should be made high in the design. In order to obtain a high performance ratio, a relatively large number of stages would be indicated. Actually, a range of 30-40 stages would probably be selected for a plant to operate at the Salton Sea. Since the plant at San Diego has 36 stages, the basic process is quite simi- lar and the detailed description of the process will not be repeated in this section. One Important consideration is the prevention of scale in an evaporator. With sea water this can be accomplished by the addition of certain chemicals which either inhibit the scale or cause a decomposition of some of the scale-forming products. An examination of Table 3, which compares the composition of the water of the Salton Sea with Pacific Ocean water, shows that the calcium is about twice as concentrated and the sulfate is about -18- three times as concentrated In the Salton Sea as in the Pacific Ocean. Consequently, the scaling potential, especially of calcium sulfate, is much greater. The control of calcium sulfate scale in operating plants is currently effected by keeping the concentration and temperature below values that cause saturation. For scale control of Salton Sea water it is necessary to remove one or the other of these ions in a pretreatment step. Because this water is a diffi- cult water in terms of scaling potential, the cost estimate in- cluded an ion exchange bed to remove sufficient calcium to prevent scaling by calcium sulfate. In addition, acid would be required to decompose the carbonate to avoid scale by calcium carbonate and magnesium hydroxide. Such a procedure is normally called pH control of scale. With this rather elaborate method of scale control and by limiting the temperature to 195°^ the scale could probably be prevented in the evaporators. However, because of the relatively low temperature of operation and the cost of scale prevention employed, the cost of the water was increased sub- stantially over a similar operation on normal sea water. The operating cost of the three 100,000 gallons per day plants, when operated to produce an average of l60 acre-feet per annum, is approximately as follows: Fuel Oil $110 per acre-foot Electrical energy 11 Chemicals 32 Materials and supplies 10 Maintenance 25 Operating labor 62 Total: $250 -19- When the amortization costs are added, the equivalent annual cost is $580 per acre-foot. Economics of Conversion The department is studying the application of saline water conversion practices to the development of waters other- wise unsuitable for their intended use. Such waters include sea water, brackish water, and treated waste water. Because the economics of conversion Is closely related to the techniques of conversion, a prime area of departmental interest is one of economics. In the past year, the department has surveyed many cost estimates and evaluated some of the more reliable estimates of saline water conversion which have been offered by designers, manufacturers, research institutions, en- gineering firms, and others. The preliminary results of this economic evaluation as it applies to conversion by electrodi- alysis, by distillation, and by the application of nuclear and solar energy, are discussed in this section of the bulletin. Some of these estimates are summarized in Table 5. Electrodlalysis - This is the most widely used process today for conversion of brackish v/aters. An example of a modern electrodlalysis plant is the 650,000 gallons per day brackish water conversion plant recently completed by Ionics, Incorpo- rated (6) for Buckeye, Arizona. At the actual load of slightly less than 50 percent of capacity. Ionics estimates the cost of -20- < UJ » H si ^^ (J "^ lO < < o 1^^ z > UJ Z q; o U Q. D 0> 4) II X E 6? ai .-O o o ^ o JS b ^ i * .€ = E ;: E si 5 S - — o o ii o m •- o> o c c £ o -z 0) 4> * D ^ in -□ 3 IS I oO , «> « .E a o ^ o i -o -D « • cl-u. C L lO 0> O (N » s- . CO a u is » £ " o » 11 « CN a> o E J> 1^ O 4) -O c c - o CQ w o •— So *- ^ i " - F - Jo ^ O 00 S Q-00 ° Ol » »1 ,. p - Jo ^ O 00 :z o c^ o o E 0) o 5 o * E « _f- 0) o — -,, T ^ui — O — U — O _l-o Sc Sc 2c D ^ 2 *S Q ';: S -D o) t— CM .— n si J? -§. eg c c S 'i ^ il I? CO O u — -21- C o .t: " .r Q. * >. o -^ c o n ^ O - Q- i o. u >. o E ? S^S u ^*° i Q E.2£ 5?5.l~ < o v» 5. D ca < I? « E o •- « e « N > o"^ a.. ° E « .- O -T E • »o *^UJ -a o o -o o -^ O ffl o , O o) » u O o O ■" ^ Z 3 ^ ;; a a J. J O c c 1 o o c o u u o c o u lear react( cannot be en worked iory first. 9- u u o o u -. » - u 3 j3 « X •^ ^ *■ — w o o « O 0* i o c c «.«-= = o E o E • ^5 • ja • D ■D 5^ 8 N o E & & 5 o-c « o o e = E (N 3 3 D /> *0 ^ c c ° E XQ:r£ 5 * '^ ^ o V*. a. o JC c o> *- o .2-0 2 - -S^ 2 ^ oi u. u. _i-o O X n a lU -O u £ < t I J < -22- water at the plant site of $l66 per acre-foot. On a full-load basis, the company estimates that the cost would he about $100 per acre-foot. These estimates appear to be realistic costs for electrodlalysls plants that can be built today. For comparison, a recent estimate by the department of the canalside rates of v;ater delivered through the authorized State Water Facilities to reservoirs in Southern California were estimated to average about $65 per acre-foot. The aqueduct water costs are not directly comparable with converted water costs. In the case of the brackish v/ater conversion plant, local pumping and distribution costs would have to be added to obtain the cost to the consumer. In the case of reservoir storage water, costs of piping for gravity feed and local distribution costs v/ould have to be added to obtain the cost to the consumer. To make a direct comparison, a specific case would have to be considered. Distillation - Among sea water conversion processes, distillation is the only one that is used to any extent on a commercial scale. Actual costs of operating plants are very difficult to obtain, but it is probably safe to say that there are not many plants producing water for less than $1.25/1,000 gallons. In contrast to the dearth of costs reflecting actual operating experience, there is no lack of estimates of proposed plants, many being based upon little more than laboratory testing. Others, however. -23- are the result of careful engineering studies and analysis by responsible companies and reliance may be placed upon them. Some of these are listed in Table 5. One means of gaining economies in conversion by distil- lation is to combine power generation and conversion in the same plant. An interesting proposal was made by Westinghouse Electric Corporation (?) for such a plant. In this application low- pressure steam that has little value for power production would be used to heat saline water in a distillation process. The energy component of the water cost would be the value of the low- pressure steam to the power production unit. This value is con- siderably less than it would be if fuel were used directly to produce steam for the conversion plant. Based on private utility financing and for large plants (up to 150,000,000 gpd), Westinghouse estimated the cost of con- verting sea water to be about $135 per acre-foot. The department has estimated that with municipal-type financing, the estimated cost of water would be reduced to about $80 per acre-foot. Further reductions are in sight as a result of current technological improvements. The advent of interconnected power systems within the State in a few years will make it possible to tie large-capacity base-loaded electric power stations to conversion plants. It is expected this will offer attractive conditions for combination plants in some parts of the State, especially in coastal areas. -24- Nuclear Energy - Since energy costs may range up to 50 percent of the total cost of converting sea water, such costs represent an attractive target for reduction. In fact, without effecting drastic reductions from present energy costs, there seems small hope that really impressive gains can be made in economics of conversion. Hammond (8,9) has proposed that large fast-breeder thermal reactors be used to produce steam to distill saline water. Even though fast-breeder reactors have not been built on any scale so far, it is stated (8) that there appears to be no technical reasons why such reactors cannot be built. The attractiveness of these large capacity fast-breeder reactors is in the low cost of the energy produced. It has been estimated (8) that steam can be produced for about 12j^ per million Btu with a 1,700 mwt reactor, and 2.5;^ with a 25,000 mwt reactor. These reactors are capable of producing sufficient energy to supply saline water conversion plants with capacities of 100,000 and 1,000,000 acre-feet per year, respectively. This proposed scheme was made formally (lO) by the Atomic Energy Commission's Oak Ridge National Laboratory. It is now being evaluated by reactor development experts in the AEG.* *A Task Group has been appointed with members of the AEG and the Department of the Interior to more completely evaluate the economics of large dual-purpose plants. It is expected a final report will be issued by the Task Group in I963. -25- The original idea has been expanded (ll) to Include an evaluation of four reactor types, one close to existing tech- nology and three more advanced concepts. The one closest to ex- isting technology is a heavy-water-moderated, boiling light -water- cooled reactor.* The others include a fast-breeder and two thermal breeders. It is anticipated that the initial estimates will be firmed up by the additional evaluations planned for 1963. While the fast-breeder reactor combined with a distil- lation process for conversion of saline water cannot be built today, the attractive economics are of considerable interest. The estimated cost (8) of converted water in plants with capacities of 100,000 and 1,000,000 acre-feet per year are about $70 and $35 per acre-foot, respectively. Hammond's estimate for a 15*000 acre- foot per year nuclear powered conversion plant of $215 per acre- foot is not competitive with a conversion plant using fossil fuel at current prices in the State. This is because this reactor con- cept is not competitive with a conventional steam boiler in this size range of 150 mwt. * Hammond has pointed out that a natural uranium heavy-water- moderated reactor burns a cheap fuel and produces enough Plutonium credit at present prices to offset burnup and most other fueling costs when .constructed in large size. Because such a reactor could be built today, it may be a strong contender for sea water conversion in the near future. -26- Solar Energy - The department had previously had an evaluation (12) made of the possibility of using solar energy to heat large amounts of saline water in ponds covered with layers of plastic glazing. The heated water was to be evaporated in a multistage flash evaporator to conserve energy. A paper was prepared by the department based on this more extensive report for presenta- tion at a symposium (l3) of the American Chemical Society on saline water conversion. A summary of the report is given in Appendix B. The main conclusion reached was that^ at the present time, in most of the State the price of alternative sources of energy is less than the cost of capturing solar heat; hence, other energy sources would normally be selected. However, the cost is such that in some of the isolated desert areas of the State there may be an application in the future, provided a demand develops for additional water. Survey of Brackish Water Areas A reconnaissance study of selected communities in Southern California where saline water conversion might be em- ployed in the future, revealed twelve potential sites. The means of determining the sites was fairly selective as can be seen from the following criteria: 1. Alternative fresh water supplies would either be nonexistent or very expensive. -27- 2. A supply of saline water would be readily available. 3. A present or future demand for fresh water existed. 4. Survey excluded areas within general service area of the California Aqueduct, with the exception of some "fringe areas." 5. Areas were already presently developed or partially developed and converted water would only augment the present supply. 6. Survey generally included only those areas in which the total dissolved solids of the available water averaged more than 1,500 ppm. The twelve localities, together with the information presently available, are tabulated in Table 6. Data on which to base accurate predictions are in many cases not available. Con- sequently, much of the information presented in Table 6 can only be used as a guide or an indication of a trend. A survey of local conditions, in order to obtain more accurate information, would probably be warranted for areas in which a trend toward poorer quality is indicated as the water use or reuse is intensified. The New and Alamo Rivers area represent a yield of 350,000 acre-feet per annum which is available for exchange. San Diego, for example, might be able to increase its supply from the Colorado River by converting the saline water from the New and Alamo Rivers for use by consumers in the vicinity of the two rivers -28- < a. ^ E I "-S £ • s E « C V) o S • •5^ • " -t: E i E E 5 _E o Q. >s — — c q: o o 4: -o o a. E J » E 2 Z < < _I Z a. q: z o o u. fcO -J q: < HI u > z z o u I q: K UJ «o D 1- O < lU t-0 s _] CO z LU < »/> z < _i UJ < q: CO < q: z O o u. < 1- < UJ Q to U UJ < -1 CO CD l>0 o 0. o 8 _© D 4_ o -£) >. jC O j: -o D > D c O 3 C ja (A i 4_ >* "o W 0) "5 w 3 c E "y 0} ■— o 3 O O ~ E o <4 a E o Q E £ ■- u _ Q >* "5 E o > >> o c _c "o o 9 o "o < > » _3£ O * > J -o c 3 o c 3 c 3 s i CQ o o CO o 9 z * "r UJ s i1 > > U D c 3 o o u o -5 £ 3 CO u 'Z D C is 3 C 3 o c o si u 'o o 11 3 2 o Q. E o -o c 3 o O k to CD U- O) u o> _c > a. U o» -I cn t/i O) ^ + + o o o o o o o o o o o o c c c o o CO o o CO > > s CO c^ o c o c 1 o 1 c -If ^ _1£ o c c 3 c 3 ■^ 2 ^" 3 t c — >--5 ■S "O ^ 2 o c -■5 S !•- e 0-2 °-£ o oi o u £ > _ .-- > lA « -^ — lA o o o o o o •— cs o o CO CN| o o CO CN o o ^ o> IP °E-° ? s i I O O c > - "o a « M g) o o O -c — -r o — Is >. » S c 5 T) o . c -c © g. ■S E 3 3 - O — (ft *- © i^ Q. •£■ © « - - E o o o o o o •— "" o = Co o Jo ■£ o o o o o o 1 Jl -c - - o 2 E O TJ -o .2 E o ii i: S-F, ?2 s : ». o 3 * E o — c E o o 3 E E © E o o> o - C u E < 1^ II z q: 3 3 ^ O 52 c -0 c-o o o CKo: q: oh q: ± u ^ • TJ i © E t £ 5 O — 3 O = > "o i O O © 4- gJoi Ssit; to-CQI-U o Ee — > ^ < < < .S u. d -29- I San Diego could then In turn take In exchange water from the Colorado River through the Metropolitan Water District aqueduct to augment its supply in an amount equal to the amount of saline river water converted. The alternative sources listed in the tabulation are In all cases limited either by recharge ability or for exportation. In the case of the three cities of Cuyama, Lompoc, and Santa Maria, relatively near the coast, the alternative sources are Lompoc for Santa Maria and Santa Maria for Lompoc or Cuyama, which leaves little assurance that water would be available for export. Representatives of both Santa Barbara and San Luis Obispo Counties feel confident that local water supplies will permit economic progress to continue normally for about twenty years without need of imported water. These counties have a con- tract with the department which commits them to purchase water, but allows a delay of up to twenty years before the aqueduct is built. In the interim some areas in these counties may very well make use of supplemental water by saline water conversion. Having a readily available alternative source of water also allows plans to be made on a shorter term basis, which normally means more accurate predictions can be made. Use of water for lawns and slniilar purposes in the Trona area has been discouraged not only by a limited supply, but also because of the rate structure which increases with increased use. This and other water conservation practices can stretch a given -30- supply. Because of the Imponderables Involved, accurate pre- dictions of future demands in the areas cited in the table are difficult if not impossible to make. The summary was limited to areas in which salinity aver- aged more than 1,500 ppm. If the survey had included the 1,000- 1,500 ppm range, at least 1,000 areas, mostly small, would have been included. Much of Ventura County, including Filmore and Oxnard, would be included. By excluding areas within the general service area of the California Aqueduct, coastal areas in San Diego and Orange Counties v;ere excluded. There may well be, however, local con- ditions in these counties and other areas that have small but mineralized ground water basins that will dictate the use of brackish water conversion, possibly to meet future standards for domestic water supply. Public health aspects of the use of water with rela- tively high total dissolved solids remain to be resolved by the Department of Public Health. The issuance of temporary permits for use of water greater than 1,000 ppm total dissolved solids is a complex subject. The Department of Public Health has planned a program which, when completed, should serve as a guide in es- tablishing limits of dissolved solids for domestic water supply. The program has not yet been initiated. Temporary permits are currently issued for use of water with up to 1,500 ppm of total dissolved solids. The temporary -31- permit will be in effect in most cases until Department of Public Health standards are established, or until the problem is resolved by the development of a water supply of better quality. A special hearing is required before the State Board of PuUIi©' Health will permit the use of domestic water containing more than 1,500 ppm of total dissolved solids. Once limits of dissolved solids have been firmly estab- lished, temporary permits to use water containing a greater amount of dissolved solids would have a definite time limit. After limits of dissolved solids have been established by the Board, the esti- mation of the application of converted brackish water can be made with more accuracy. As growth occurs in these and others of the numerous communities dependent upon water supplies of rela- tively high salinity, new sources of supply are likely to be of lower quality. It is anticipated that conversion will become increasingly important as a means of extending a water supply or of making available new sources, otherwise unusable. Currently, the State Department of Public Health lists nine areas (l4) of the state which do not presently have public water supplies meeting the "full" permit requirements of that department because of excess salinity. The following is a list of the areas: 1. San Diego County coastal basins. 2. The San Juan Capistrano area of Orange County. 3. The Salton Sea-Coachella Valley area of Imperial and Riverside Counties. -32- 4. The Chino area of San Bernardino County. 5. The upper Mojave Desert Basin lying in parts of Los Angeles, San Bernardino and Kern Counties. 6. A number of the Ventura County basins Including Slml Valley, the vicinity of Oxnard, the vicinity of Ventura, and parts of the Santa Clara River Basin. 7. Parts of coastal ground water basins In Santa Barbara County, 8. Santa Barbara, Lompoc, and Santa Maria and portions of Santa Barbara, San Luis Obispo and Kern Counties extending from Maricopa, Cuyama, Into the Cholame and Parkf leld areas . 9. Some of the Inland ground water basins of Monterey County and San Benito County. In order to more completely evaluate areas In the State in which brackish water occur, an Inventory of saline water is being made. A preliminary Inventory for Northern and Central California has been completed. Areas of different total dissolved solids have been categorized as follows: Nonsaline 0- 1,500 ppm Slightly saline 1,500- 3,000 ppm Moderately saline 3,000- 5,000 ppm Saline 5,000-10,000 ppm Very saline over 10,000 ppm It is anticipated that in some of the areas having saline ground waters, future requirements of water quality improve- ment will result in an application of conversion for the removal of dissolved solids. In addition. Information on brackish water areas is expected to be used in the planning of water requirements and project staging as these studies progress to the point where the conversion processes can be Integrated Into the program. -33- PART II. OTHER CONVERSION ACTIVITIES WITHIN CALIFORNIA A. UNIVERSITY OF CALIFORNIA INTRODUCTION Saline water conversion research began at the university during the fiscal year 1951-52. The objective of the university In conducting research work in saline water conversion Is to per- fect or develop means of obtaining potable water from saline sources at costs competitive with alternative sources of supply. Because removal of dissolved solids from brackish water and waste water is expected to be less costly than removal of solids from more saline sources or sea water, increasing attention Is being given to research methods appropriate to these less saline sources. The research activity has been sustained at nearly the same level for several years. During the current fiscal year the State Legislature appropriated $33^^900 for conversion research (l5). Some additional funds are also made available by the Water Re- sources Center of the university. The total of the current budget is $432,957. The university conducts the research and development at its Berkeley campus, Richmond Field Station, Los Angeles campus, and the San Diego campus. The facility at the San Diego campus was completed last year. It is a building located adjacent to the inshore end of the pier used by the Scripps Institution of Ocea- nography. The primary purpose of this facility is to test processes that have reached the pilot plant stage and for which a supply of -35- clean, full-strength sea water is desired. The rotating still described in the section of current projects has been installed and initial tests are now under way. Testing of a membrane suitable for a reverse osmosis application was initiated later in the year. REPORTS The university issues annual progress reports (16,17) in which the work in progress is described. In addition, several detailed reports on specific projects were issued during I962. A list of these reports is given in Table 7. Copies of these reports may be obtained from the university.* *From Sea Water Conversion Laboratory, University of California, 130I South 46th Street, Richmond, California. -36- 1 TABLE 7 REPORTS ISSUED OURINe 1962 BY UNIVERSITY OF CALIFORNIA WATER RESOURCES CENTER, SEA WATER CONVERSION PROGRAM Resources CCRTEN No. Title Univ. Rept, No. Date Author "Oeterhimtioii of Coefficievts for TNERnODYNAniC EQUATIONS FOR Dt- TiRiiiNiNs THE Properties of Sea Water, Particularly Vapor Pressure' "Effect of Stress on the Electrode Potential of Silver, Steel 4N0 Brass in Aqueous Solutions. "Salt Water Oemineralization With a Modifies Aquafresn Electros ialytic Stack." "Sea Water Oeminiralization by Means OF A SEniPERMEASLE MEHBRAM*" "Saline Water Research SunnARY, June 1962" PRO6RISS "Effect of Illumination on tnc Electrode Potential of Copper anb Silver Single Crystals 11 Aqveous Solutions." Effect of Morocmromatic Illuni- NATION 01 TNE ELECTROBE POTENTIAL OF Copper and Tii 11 Aqncous solvtiou." "Sea Water Oehineralizatior by Means OF A SEHIPERWABLE ^HBRANE," - Prosress Report July 1, 1961 > Oecehber 31, 1961. "Salik Water Ocmineralizatioi by Electrooialtsis with Componehts Manufactures by Ionics, Inc." "Berkeley Progress Report for tnc Year ebbing June 30, 1962." "Condensation Coefficient of Water" "DcBisi, Dcvelophebt & Test IBS of a 600-6AL. per bay Oshotic Sea Water Oesalinization Cell." "Sea Water Oehin. by Kars of a Schi- PCRncASic Membrane" (Progress rept. J* I. 1 TO 6/30/62) 44 51 52 54 55 57 58 60 62 63 86 61-80 Feb. 1962 62-12 Mar. 1962 75-29 62-26 62-33 62-35 May 1962 June 1962 July 1962 Aug. 1962 62-40 Aug. 1962 62-41 75-29 75-30 62-63 62-61 Aug. 1962 Aug. 1962 Aug. 1962 Oct. 1962 Nov. 1962 Occ. 1662 Charles Gastaldo Keb Nose SwiE-lB Tan Pascal M. Rapier Susan WE irer Walter K. Barer S. LOEB Ken No be 0. A. Chance H. A. Arbit K. Nose S. LOES Pascal M. Rapier Walter k. Baker SUSAR A. Weiner Khosrow Nabaviah LeRoy a. Bromley S. LecB F. Milstein S. LOEB -37- PROJECTS A brief description of the research and development projects in progress during 1962 at the several campuses of the university, are contained in this section. For detailed infor- mation, the reader is referred to the university's annual reports (16,17) and special reports of the Sea Water Conversion Program as listed in Table 7. 1. Electrodialysis . In this project the objectives are to determine the optimum conditions under which to operate electrodialysis apparatus considering the effects of polarization and scaling on current density. Attention is also being directed to the design of electrodialysis stacks in which the energy demand is minimized when operated with waters of high salinity. 2. Carryover Studies . In this project the objectives are to measure the fog carried over into the condenser by the steam formed during the flash evaporation of warm water and to develop a device for minimizing the amount of such carryover. 3. Scale Studies . In this project the objectives are to determine the equilibrium scaling tendencies in saline water concentrates at temperature above the normal boiling point and to formulate equations or charts to represent the data obtained. -38- 4. Ion Exchange . In this project the objectives are to study the use of exchange materials for the softening of sea water with regeneration by the concentrated brine and to investigate the energy requirements of selected exchange materials. 5. Direct Contact Heat Transfer . In this project the objectives are to develop devices for the exchange of heat between saline water and a liquid which is iin- mlsclble with water and to Incorporate the devices into a pilot plant. 6. Freeze-Separation . In this project the objectives are to obtain fundamental data on the solubility of carbon dioxide in saline solutions and to make a design study of a system for conversion using carbon dioxide hydrate. 7. Thermodynamic Studies . In this project the objectives are to evaluate the implications of thermodynamics on several methods of conversion and to evaluate the theoretical gains to be made by increasing the brine temperature in distillation processes. 8. Solar Distillation Studies . In this project the ob- jectives are to test the latest designs of solar stills evolved by the project and to evaluate solar energy collectors without the use of a glass cover. 9. Multiple Effect Rotating Still . In this project the objectives are to test a previously developed pilot plant on sea water and to evaluate the results of the operation. -39- 10. Capillary Control of Vapor Transfer Gap . In this project the primary objectives are to demonstrate that thin films of vaporizing solutions can be held at very close and uniform distance (O.OIO") from each other and to develop and construct experimental sheets that can be used in the tests. Pertinent data are also being measured. 11. Pilot Plant Development . The current objective In this project is to investigate methods of scale control in distillation plants through in situ seeding techniques at elevated temperature. 12. Demlneralization by Means of a Semipermeable Membrane . In this project the objectives are to develop membranes suitable for the reverse osmosis process and to in- vestigate the nature of the associated apparatus re- quired for the separation. In addition, pilot plant equipment is being tested on saline water. 13. Techniques of Optimization . This is a project in which the objectives are to study the theoretical relation- ships of thermodynamics and economics on saline water conversion. The theoretical calculations are applied to the optimization of the operation of conversion processes. -40- 14. Transport Phenomena Near a Liquid -Vapor Interface . In this project the objectives are to obtain basic Information on mass and heat fluxes near a llquld-vapor Interface and to study the kinetics of steady and non- steady state evaporation. 15. Experimental Heat Transfer Studies . In this project the objectives are to Investigate the physical factors influencing the evaporation of saline water from wiped and falling films. The effect of flow rate, temperature and temperature difference, pressure, salinity and feed distribution on evaporator performance, geometry and environment are being investigated. 16. Waste Water Reclamation Biological Systems . In this project the objectives are to study the removal of dis- solved materials, including viruses and detergents, by prolific algae growth. These studies are conducted with both bench scale and pilot plant equipment utilizing both raw and treated waste water. Feasibility of practical application of activated-sludge-algae-pond processed water to actual sites will be investigated. 17. Corrosion Studies . In this project the objectives are to obtain fundamental knowledge of metal behavior in aqueous solution under various conditions . -41- B. OTHER AGENCIES In addition to state agencies, other public agencies and private companies are involved in saline water conversion within California. These activities are described in this section. COALINGA The electrodialysis conversion plant at Coalinga was the first in the United States to use converted water for a munic- ipal supply. The plant which has been in operation since 1959 has completed another successful year during 19^2. The final payment for the plant was made out of water revenues in September 1962. Details of the plant and equipment have been previously described (1,18,19,20,21). The feed to the electrodialysis unit is from local wells. The salt concentration varies somewhat. The range of total dissolved solids is usually from 2,100 to 2,400 ppm. The product is normally below 5OO ppm, Tjrpical analy- ses of raw well water and demineralized product water distributed in Coalinga in March and August 1962 are given in Table 8. -42- TABLE 8 RETORT OF CHEMICAL ANALYSIS OF C0ALIM6A WATER^ March 1$« AOOMST i9«r Dl milERALIZECi Oe niNERALIZEB OCSCRIPTIOI Raw Well Water PROeUCT Raw Well Water Product CONPSS ITE CONPMITE Composite Compos ite Total Solus pph 2160 388 2700 568 Haroiess PPn 564 37.5 801 86 Alxaliiitv ppn 130 14.0 121 29 Calcium pp« 132 8.0 169 15.6 Masks mn ppn 57.1 4.3 92.4 11.5 Iron (totai) pp« <0.1 < 0.1 0.04 0.03 MANOAKSt PPN 0.21 < 0.05 0.05 < 0.05 Sob 1 IN PPN 423 80 512 126 Potass iBH ppn 14.4 1.1 11 1.7 BOROR PPN 2.8 2.8 2.1 2,3 Chloriies ppn 209 7.5 340 29.2 SULPATES PPN 1060 189 1250 287 Fluorides ppn 0.2 0.1 0.15 0.15 Nitrates as NlTROOEH PPN 0.T5 < 0.1 0.75 0.2 PH 8.2 7.2 8.2 7.9 (1 ) - Reported by State Department of Public Health -43- OFFICE OF SALINE WATER In .the federal government, the Office of Saline Water (OSW), is assigned primary responsibility for the research and de- velopment on saline water conversion. The OSW contracts all of the work to other government agencies, universities, and to private companies throughout the United States and this year it entered into a contract with a company located in England (22). The activ- ities of the OSW are adequately described in its annual reports,* For additional information about the OSW, the reader is referred to those reports. During the year the OSW announced the availability^ of nine research and development progress reports, A list of these reports is tabulated in Table 9. Each progress report covers in detail the work done by a particular contractor on a specific process or conversion technique. In addition, the proceedings of a saline water conversion conference were published (23). Several of the contracts entered into during 1962 by OSW have been with agencies and companies in California. The scope of the work under OSW contract within the State is briefly des- cribed in this section of the bulletin. Demonstration Plant The operation and design of the multistage flash evapo- rator demonstration plant at San Diego has been previously des- cribed (1,2,3*^). A brief process description is included in Part I of the bulletin. *OSW Annual Reports 195^-1961. -44- TABLE 9 OFFICE OF SALINE SATER RESEARCH AND DEVELOPMENT PROGRESS REPORTS (Available in 1962) No, Title 50, "Study and Evaluation of Solan Sea Water Stills (Sept. 'SI) 51, " Invest i«AT ION and Development of an Electnolytic Systeh for the Conversion OF Saline and Brackish Water" (Auo. 1961) 52, "Survey of Physiolosical Mechanisms of Sodium and Chloride ion Transport and 0esi6n or experiment for application to demi neral iz i ns saline waters," Part. 1 "Laioratory Evaluation of Use of Alsae in Saline Water Conversion. Phase 1 Final Report," Part. 2. (Sept. 1961) 54. "Evaluation of a Tnin-Film Sea Water Distillation Unit for Marine and Shore Base Applications." 55. "Development of the Solvent Dehineralization of Saline Water. " (Sept. 1981) 56. "Vapor Compression with Secondary Heat-Transfer Media." (Dec. 1961) 57. "Removal of Scale-Formih« Compounds from Sea Water." 58. "Oemineralization of Saline Water sy Electrically—Inouceo Adsorption oh Porous Carson Electrodes." (March 1962) 60. "Development of an Improves Soiar Still." (March 1962) PB Order No. * 171934 171929 171930 181041 131036 181090 181118 181142 181144 *AvAILAiLE FROM OFFICE OF TECHNICAL SERVICES, U.S. OtPARTHENT OF COHICRCE, WASNINSTON 25, D. C. -45- During the early part of the year, Westinghouse Electric Corporation, the construction contractor, completed the plant startup phase and turned the plant over to the OSW on March 5, 1962. In January 1962, the OSW announced (24) the selection of Burns and Roe, Incorporated, to manage and operate the plant under a cost-reimbursable-plus -fixed-fee contract. The estimated cost (25) to the government under this contract for fiscal year 1962 (December 20, 1961-June 30, I962) is $106,786. This is ex- clusive of the cost of fuel and electric power which was estimated to amount to about $125,000 per year. The Burns and Roe contract was renewed (26) for fiscal year 1963 for $200,732. The plant was dedicated March 10, I962, by Secretary of the Interior Stewart L. Udall, Governor Edmund G. Brown, and other national and local civic leaders. It was estimated that about 2,500 people attended the dedication. A majority of the people toured the facility and tasted the product water. The cost of the construction and initial startup of the plant was $1,663,246. The State contributed one-half of the cost of construction. The plant has not been in operation a sufficient length of time for any formal reports to have been prepared. The Office of Saline Water plans to issue reports at appropriate intervals. The first report is planned for the period March 1962-June I963. In general, the multistage flash process has performed according -46- to expectation. The operation of the plant has been gradually improved as more has been learned about the process. Intimately related to the overall operation, but not the process per se, is the sea water feed to the plant. Considerable amounts of sea grass and kelp are drawn through the intake line into the intake pit. This material has caused considerable diffi- culty in various parts of the plant. The downtime required to clean such material out of the equipment has resulted in a reduced output . Modifications made to the intake facility have reduced the amount of marine growth getting into the plant. However, these have not been completely effective and the OSW is now con- sidering major revisions of the intake facility, which should greatly reduce the amount of marine growth that gets into the plant. It is encouraging that none of the major intake facilities operated by the power companies along the coast of California ex- perience this type of marine growth in the intake facilities, indicating marine growth is more of an isolated problem, rather than extending along most of the coast. Research and Development . The Office of Saline Water had ten organizations within the State under contract during 1962, to perform research and development work in saline water conversion. The scope of the work of each contractor is described in this section. -47- Aero.let -General Corporation was awarded three contracts (26,27) totaling $293,400 by the Office of Saline Water to conduct basic research and development work in the reverse osmosis process. This process was pioneered by the University of California (28,29). The work under the contracts was started during the last half of 1962. The basic research program is aimed at developing membranes suitable for the reverse osmosis process. It will in- clude a fundamental study of the mechanism of water transport and ion migration through membranes. In the development contract the company is testing and evaluating membranes in a 1,000 gallons per day pilot plant. The design and testing of concepts for process equipment is also a part of the program. Bechtel Corporation was awarded a contract for $49,210 to determine the optimum size of saline water conversion plants (30) . The study included an analysis of the effect of plant size on the cost of fresh water obtained from saline water. The pro- cesses evaluated are the three now in actual operation as part of the OSW demonstration plant program. The processes are long-tube vertical multiple effect evaporation, multistage evaporation, and electrodlalysis. Details of the analysis are expected to be available in I963. The basis of the analysis was the demonstration plants for which some actual cost and operating data are available. Bechtel separated the cost of the experimental features to arrive at a cost representative of an actual production plant of the -48- same size as the corresponding demonstration plant. The equip- ment and cost estimates were then scaled to large capacity plants. Curves were prepared showing the effect of plant capacity on the cost of water. More recently (27) the company was awarded a contract for $85,200 to conduct cost studies pertaining to various sizes of large-scale saline water conversion plants. The work was begun near the end of the year. FMC Corporation constructed a 4,600 gallon per day vapor reheat distillation process pilot plant utilizing liquid- liquid heat exchangers under a $139,750 contract. The contract was awarded late in 1961 by the Office of Saline Water (31). In the system under development, twin columns of oil are used as the heat exchanger. Fresh water is cooled in one column and sea water is heated in the other column, while the oil flows through both columns in a closed loop. In the vapor reheat process, the metallic heat exchange surface used in conventional distillation processes is eliminated. Under the contract, FMC built and tested equipment to evaluate two oil liquid-liquid heat exchangers and a vapor reheat column. These two components were then tested as an integrated pilot plant utilizing a 5-stage column. This concept has been under development for several years. The prior work has been re- ported (32). -49- During the year the Office of Saline Water made two ex- tensions to the contract (26,30) for $8o,000 and $30,000, respec- tively, for the company to continue the investigation and analysis of heat-exchange without metallic heat-exchange surfaces for use with its vapor reheat process. The economics of a large capacity conversion plant (lO million gpd) utilizing this process have been evaluated by the FMC Corporation. In a full-scale plant, the outer shell may be as much as 50 feet in diameter and probably be constructed of pre- s tressed concrete. The estimated cost of water from such a plant is in the range of 50 to 60 cents per 1,000 gallons (23) when based on OSW standardized cost procedures (33). Ford Motor Company , Aeronutronic Division, was awarded a contract (3^) by OSW for $69,872 late in 1962. The majority of the work will be performed in I963. The contract is for basic research in the field of thermal diffusion (35). The principle involved is based on the separation obtained in a multicomponent system as a result of a concentration gradient that can be induced by a thermal gradient. Substantial concentration gradients have been observed in the steady state. The work will be basic research conducted in the labo- ratory. Once the parameters have been established, the laboratory work will consist of making measurements on appropriately chosen variables. -50- It is not expected that thermal diffusion will neces- sarily become a commercial conversion process. However, basic research of this type on thermal diffusion and mass diffusion should give answers which may improve current saline water con- version processes. General Dynamics Corporation , General Atomic Division, was awarded a $150,000 contract by OSW in May 1962 to study a process utilizing a combination of membranes and pressure, which is known as reverse osmosis. Much of the prior fundamental work on this process was done by the University of California (28,29, 36,37). This process has the potential advantage of requiring less energy than other conversion processes. It may also find application in waste water reclamation. In this process the usual osmotic process of spontaneous selective flow of a less concentrated liquid solution to a more concentrated solution through a semipermeable membrane is re- versed by applying high pressure on the more concentrated solution, When this technique is applied to saline water, salt is held up by the semipermeable membrane and water containing much less salt collects on the other side. General Atomic is conducting preliminary work and evalu- ating the physical and chemical characteristics of selected mem- brane materials to find a material that will permit a high reverse flow rate and not deteriorate in salt water. -51- Leslie Salt Company was awarded a contract (26) for $15,000 by the Office of Saline Water to study the technical and economic feasibility of recovering fresh water from sea water in conjunction with solar salt-producing operations. The work done during 1962 consisted of a literature survey and an evaluation of the combination. The company has concluded that a floating plastic con- denser appears to offer an attractive means of water and salt production in many areas of the world. An additional advantage of the floating condenser, especially in areas where rainfall is I significant, is that it prevents dilution of the brine by rain. This has the effect of increasing the net annual evaporation rate. There is very little information available on the appli- cation of solar collectors to large ponds as found in the salt Industry. Experimental work is Indicated in order to evaluate the economic feasibility of this combination of water and salt production. • Narmco Research & Development was awarded a contract by the Office of Saline Water for $35,730 to predict the influence of materials and operational variables on the effectiveness and per- formance of the vapor gap osmotic distillation process. The State of California, Department of Water Resources is contributing 50 percent of the cost of the contract. This concept was developed by the University of California (38,39*^0,41). A description of the process is contained in the section of the bulletin devoted to the activities at the university. -52- Narmco is analyzing the effects of temperature, pres- sure, geometry, and other variables on the efficiency of the process. It is determining qualitatively the effects of fluid- flow through porous media and membranes, water vapor diffusion through gas -filled gaps and backward diffusion of dissolved mole- cules in fluid through osmotic membranes. The company also plans to perform laboratory tests determined to be necessary to verify theoretical analysis, A survey is also being made of the properties of existing materials to determine applicability of these materials for direct incorporation into test module designs. Stanford Research Institute was awarded a $31,200 contract by the Office of Saline Water (30 ) to conduct research on crystalline monomolecular membranes of controllable permea- bility. The work is primarily concerned with the synthesis of two dimensional crystals in which holes exist to allow passage of ions and molecules below a specific size. During 1962 crystalline sheet polymers were prepared that may be useful in ultrafiltration. The specific application is in the removal of dissolved ions from saline solutions. A membrane that contains pores or interstices of molec- ular dimensions is desired. Such a membrane would permit the passage of the small water molecules, but not the larger hydrated ions of sodium, chloride, and other ionized salts. -53- There are two parts to the program (42) . One part is concerned with the synthesis of the necessary low molecular weight reactants and the other with the interaction of these re- actants in dilute solutions. The interaction takes place either at a liquid surface or at the interface between two liquids. Another contt-act (2?) was awarded late in 1962 for $35^000 to study the methodology for comparative engineering a- nalysis of alternative processes for saline water conversion. The University of California was awarded a contract (30) for $39,010 to conduct research in salt transport mechanics and salt tolerance of plants. The research is being conducted by Dr. Bnanuel Epstine at the Davis campus. One part of the experimental study is concerned with studying living cells especially the physiological and biochemical processes of plants. Since plants are most effective in salt re- moval and selectivity, more knowledge is needed on the mechanism. As more information is developed, it may be possible to obtain membranes from plants suitable for use in dialysis processes. Another possibility is that the knowledge can be applied to the manufacture of more effective synthetic membranes. The other part of the contract involves the development or creation of useful plants that can stand a higher level of salinity than existing useful plants. In irrigation, agriculture salt relations of plants are extremely important. Even a small -54- Increase of salt tolerance of existing crop species would extend the usefulness of present or potential supplies of water which may be too saline for the plants at present. Western Independent Research Laboratories was awarded a one-year contract (30) by the Office of Saline Water for $54,00? to perform exploratory studies on demlneralization of water through pressurization cycles on ion exchange materials. The work under this contract has included both a technical dissertation on theory and basic laboratory investigations with saline solutions. The theoretical energy of separation is very low, hence the process is potentially attractive. The concept is based on the Donnan membrane equilibrium theory of electrolytes. In the particular application conventional ion exchange particles are used. Very high internal pressures build up during the separation of electrolyte from water. The purified water can be removed from the exchange material by pressure. UNITED STATES NAVY The U. S. Navy, at its Civil Engineering Laboratory (NCEL) at Port Huenerae, operates a marine testing facility for saline water conversion equipment which is of interest in its operations . The Navy is interested In portable land-based or ship- board equipment. It evaluates the operating characteristics of the equipment and runs independent tests. -55- During the year NCEL has been operating (43) a mult is tc flash evaporator which derives its thermal energy from the jacket water and exhaust gas of a diesel generator. The evaporator is capable of producing 200 gallons per hour of potable water from sea water. The NCEL prototype unit consists of two separate com- ponents which are housed in separate areas. The feedwater heatei is mounted adjacent to the diesel generator. The 24-stage evaporator consists of four rectangular boxes. Tests with this unit at NCEL show promise for use at Nav5 bases throughout the world. The Coast Guard is currently field- testing the unit on Marcus Island in the North Pacific Ocean. The Navy permitted the University of California to test its 500 gpd reverse osmosis pilot plant (44) on sea water at Port Hueneme. The pilot plant was tested during April and May of 1962. While the tests were generally satisfactory, it was dis- covered that particulate matter in the sea water contaminated the membranes and resulted in a higher fraction of the salt passing through the membrane than during periods when the sea water did not appear to contain as much particulate matter. PRIVATE COMPANIES Several companies in California are also doing research and development work on saline water, conversion. In addition, some of the large power companies have not only undertaken -56- development work in saline water conversion, but also use distil- lation processes to produce boiler quality feed water directly from sea water. Pacific Gas and Electric Conrpany . This power company pioneered in the conversion of sea water for use in boilers at steam electric power plants. The original submerged tube evaporators (45,46) installed at the Morro Bay power plant are still giving good service after seven years. During I962 they were used extensively in producing water for startup of Units 3 and 4 at Morro Bay. In addition, the company has flash-type evaporators at its installations completed this year or currently under con- struction, as follows: Morro Bay Unit No. 3 Morro Bay Unit No. 4 Contra Costa No. 6 Contra Costa No. 7 All of the flash units are rated at 50 gpm, producing boiler quality water of no more than 1/2 ppm of total dissolved solids. The units at Morro Bay are single-stage flash units oper- ating on full strength sea water, thereby reducing the salt con- centration from approximately 3.5 percent to nearly zero. The units at the Contra Costa plants will be two-stage flash units operating on San Joaquin River water. The salt con- centration varies from 100 to 5,000 ppm, depending on the season, and will be reduced to less than 1/2 ppm regardless of the con- centration of the salt in the feed. -57- The company also plans to use a single-stage flash evaporator to produce boiler quality water at its nuclear plant planned for Bodega Bay. Whereas the flash evaporators at Morro Bay and Contra Costa recycle the brine, the evaporator planned for Bodega Bay will use the once-through cycle (47) . Southern California Edison Company . The company has been operating a 26-stage flash evapo- rator with a rated output of 100,000 gpd at its Mandalay steam station since January i960. Details of the plant's design and operation have been reported previously (1,48,49,50,51*52). During 1962 it was decided to experiment with pH control to prevent the formation of scale. Equipment was designed and installed that will permit acid injection. The initial tests were started in December 1962. It is hoped the use of acid to prevent scale will permit a higher economy. Caustic is used to bring the saline solution back to alkaline after the scale-forming carbonates are removed. At the higher pH the solution is not nearly as corrosive to the steel vessels. North American Aviation . The Rocketdyne Division of North American Aviation an- nounced (53) in 1961 that it had designed and would build and operate a pilot plant to convert sea water to fresh water. The pilot plant was built and initial operation started in I96I at an ocean site near Oxnard, California, on land leased from the -58- Southern California Edison Company at Mandalay Beach. It was operated until late in I962 to obtain engineering data and oper- ating experience. The pilot plant has a capacity of 15,000-20,000 gallons per day of product water. The company expects to invest about one million dollars in research and development costs over a two-year period (53) in proving out the process. The process eliminates conventional heat exchangers in all principal sections of the freezing process (5^). It consists of four main steps: precoollng the sea water feed, freezing to produce ice crystals, separating and washing the crystals from the brine, and melting the crystals to obtain fresh water. Heat recovery is practiced in all steps of the process. The pilot plant was designed to use freezer-washer-melter equipment originally developed for the Wiegandt process (55). In the precooling step, the sea water temperature is lowered to near freezing by passing a liquid hydrocarbon compound such as octane, directly through it. The octane is previously cooled by other process streams. A more volatile hydrocarbon such as butane is used in the second steps to freeze the water. The ice crystals are in contact in the brine solution and must be washed. The fourth main step consists of melting the washed ice crystals by direct contact with compressed butane. The hydrocarbon compounds are recycled through the process. -59- The company has made considerable progress In the de- velopment of the process. This Is evident from the fact that It was one of five companies that submitted bids In July 1962 to the Office of Saline Water for construction of a 250,000 gallons per day demonstration plant based on Its freezing process (56). Havens Industries . Havens Industries Is conducting private research on the reverse osmosis process of saline water conversion. This process should require a relatively small amount of energy for conversion. It can be used for brackish or sea water conversion. Since the salt removal is a function of initial salt concentration, it is more effective with brackish water. The company is developing a membrane backing of fiber- glas and resin with controlled microscopic porosity. The reverse osmosis membrane used in the tests was developed by the University of California (28,29). The membrane will permit the passage of water., but not salt when pressure greater than the osmotic pressure is applied. The flberglas -resin backing is used as a support for the membrane. -60- APPENDIX A CONVERSION ACTIVITIES OUTSIDE CALIFORNIA A-1 TABLE OF CONTENTS Page INTRODUCTION ^'^ DEMONSTRATION PLANTS ^'^ Long Tube Vertical Evaporator ^'^ A-IO Electrodlalysis Forced-Circulation Vapor Compression -^"13 ADVANCED WASTE TREATMENT RESEARCH PROGRAM ^-'^^ RECENT COMMERCIAL PLANTS ^"^"^ SYMPOSIUMS AND MEETINGS ^'"^^ A-Pll CURRENT CONVERSION ACTIVITIES Distillation .. ^. ... A-26 Membranes • r. A ... A-26 Freezing Other '^■^'^ TABLES Table No . A-1 Saline Water Conversion Demonstration Plants by Office of Saline Water "' A-2 Partial List of Recent Conversion Plants - (In Operation or Under Construction since 19dOj. . ^ J-o FIGURES Figure No . A-1 Schematic Flow Diagram of the Long Tube Vertical Evaporation Process at Freeport, Texas -^-o A-2 Schematic Diagram of a Typical Electrodlalysis Stack A-11 A-3 Schematic Flow Diagram of the Forced-Circulation Vapor Compression Process under Construction ^ at Roswell, New Mexico A-3 INTRODUCTION In order to give a more complete picture of saline water conversion, some of the important activities in the field outside the State are included in this bulletin. The Office of Saline Water demonstration plants are briefly described. The Advanced Waste Treatment Research Program of the U. S. Public Health Service is discussed. In addition, a partial list of commercial conversion plants in operation or under construction since I96O, are tabulated to indicate that many areas, both domestic and foreign, are finding saline water conversion an aid in the solution to their water supply problems. The meetings on the subject of conversion that have been held both in the United States and in other countries during the year are briefly described. The majority of the known conversion processes have been described in the Office of Saline Water annual reports. The department also described the major processes in its Bulletin No. 93 (1). Only recent advances in some of the more promising processes have been included in this bulletin. A-5 DEMONSTRATION PLANTS The Office of Saline Water was directed by Public Law 85-883 to construct and operate five demonstration conversion plants. One of the five is the demonstration plant at San Diego, which was previously described in this bulletin. Two of the plants (Freeport, Texas and Webster, South Dakota), have been in operation through the year, and one is under construction (Roswell, New Mexico). Construction of the fifth plant is planned (57) for Wrightsville Beach, North Carolina. The capacities of the demonstration plants and other pertinent information are listed in Table A-l. Descriptions of the processes are contained in the follov;ing sections. Long Tube Vertical Evaporator The one million gallons per day demonstration plant utilizing this process is located at Freeport, Texas. The details of the construction requirements for the plant and the process conditions are contained in the bid documents (58) issued by the Office of Saline Water for the construction of the plant. In ad- dition, details of the operation of the plant have been previously described (23,59,60,61). Only a brief description of the process is given here. A schematic flow diagram of the process is shown in Figure A-l. 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The evaporation of the sea water is started in the first effect, which is at the highest temperature. In this effect steam is admitted into the shell of the evaporator. The steam condensing on the tubes causes some of the sea water to boil as it flows down the inside surface of the tubes. The vapor evolved from the boiling sea water now called brine is disengaged from the brine and is conducted to the shellside of the second effect, which is at a lower pressure and temperature. The brine is also pumped to the second effect tubes. The vapor condenses on the outside surface of the tubes, giving up its heat of condensation to the brine inside the tubes. In the second effect additional water is boiled away from the brine. This procedure of heating and boiling is repeated in each effect until the last or lowest temperature effect is reached. The brine remaining at this point is pumped to waste. It contains about four times the amount of salt as the original feed sea water. During the year the Freeport plant has been controlling scale by the addition of sulfuric acid. The addition of acid de- composes the carbonate and prevents both calcium carbonate and magnesium hydroxide scale. Calcium sulfate scale is prevented by operating at conditions of temperature and salt concentration in which calcium sulfate is not saturated. A-9 The corrosion problems (62) encountered the previous year with the steel tubes have been overcome by replacing with tubes of material more resistant to the conditions encountered in the evaporators and heat exchangers. In effects 10, 11, and 12, modified distributor plates were installed and the pumps associated with these effects were modified (23) . Also the main feed pumps between the deaerator and evaporators have been modified (23). Electrodialysis The 250,000 gallons per day demonstration plant utilizing this process is located at Webster, South Dakota. The details for the construction of the plant and the process conditions are contained in the bid documents (63) issued by the Office of Saline Water for the construction of the plant. In addition, the operation of the plant has been previously decribed (23,64,65). In this process, the salt is removed from the water by the use of membranes. The raw water is pretreated to remove iron and manganese before it is fed to the electrodialysis equipment, which is referred to as a stack. A typical stack is shown in Figure A-2. The pretreated water is divided into three streams termed dilute, concentration, and electrode stream. Each stream is adjusted to the required flow, pH, and chemical balance. This demonstration plant contains 217 membrane cell pairs in a stack. Four such stacks are used in series. The water is fed to the top of the concentration cell and to the bottom of A-10 CATION- PERME ABLE MEMBRANE ANION -PERME ABLE MEMBRANE BATTERY OR OTHER DIRECT CURRENT SOURCE ir 1 r ©. \ \ ©. \ 1 r ® / e \. © ©. \ ,© ©. \ 1 r © © ^© BRACKISH WATER y I / 1 y I / L ' I / L / L y L / ©. \ / .© 1 r © © ©. \ \ / © © \ © © \. © LEGEND © CATION (SODIUM, MAGNESIUM, ETC.) © ANION (CHLORIDE, SULPHATE, ETC.) 7 r / .© FIGURE A-2 A SCHEMATIC DIAGRAM OF A TYPICAL ELECTRODIALYSIS STACK ^ FRESH WATER ^ CONCENTRATED BRINE A-M the dilute cell. The direct current applied across the stack causes the salt ions to move toward the respective electrodes located at opposite ends of the stack. The membranes are permselective in that a given membrane will either pass anions or cations, but not both. The movement of ions is thus interrupted by the selective membranes. On one side of the concentration cell is a membrane which stops the anions such as chloride, and on the other side is a membrane which stops cations such as sodium. The cells adjacent to the concentration cell are losing ions and thus the solution becomes less salty. The dilute stream passes in series through the four stacks losing 40 to 50 percent of its salt in each stack. The dilute stream leaving the final stack becomes the product water after any posttreatment required for pH or chemical control. The electrodialysis plant was shut down in October I962 for a detailed inspection of operating components following a full year of successful operation (66). During the first year of oper- ation the plant produced approximately 75 million gallons of water. The major areas where improvements (23) were made since the original design were in elimination of air entrainment in the water which caused operating difficulties in the stack, in ad- justment in chemical additives to prevent scale, and in revision of the rinse stream to conserve acid. A-12 Forced-Circulation Vapor Compression The one million gallons per day demonstration plant uti- lizing this process was under construction at Roswell, New Mexico at the end of 1962. The details of the construction requirements for the plant and the process conditions specified are contained in the bid documents (67) issued by the Office of Saline Water for the construction and initial operation of the plant. The principle of this process has been previously described in the literature (68). A schematic flow diagram of the process is shown in Figure A-3. In this plant three effects will be operated in series with a single vapor-compression cycle operating over the total temperature range. The feed brine is treated to remove scale- forming chemicals and preheated by exchange with the product water and blowdown. The brine is then introduced into the first evapo- rator effect, which is at the highest temperature. At this point it is mixed with the stream being circulated (69,70). The steam from the vapor compressor condenses in the first effect brine heater and raises the temperature of the brine which is under forced circulation. Boiling is suppressed in the heater by the hydrostatic head. When the brine enters the evapo- rator flashing takes place as the pressure is reduced. The partially concentrated brine flows to the second effect where it is mixed with the circulating stream. The vapor evolved in the first effect is used to heat the brine in the second effect. The same process is repeated in the third effect. A-13 z o I- o 3 (£ < UJ a o < >- UJ CO o < _i O C£ o cr o u. I I A -14 The brine leaving the third effect is discharged to waste. The vapor is sent to the vapor compressor which raises the steam pressure to the value required in the first effect evapo- rator. The flashed vapor in each evaporator after condensation and cooling becomes the product. The construction contract was awarded on April 6, 1962. Construction is scheduled for completion in one year (71). Ground- breaking (72) ceremonies were held -July 10, 1962. A-15 ADVANCED WASTE TREATMENT RESEARCH PROGRAM This Advanced Waste Treatment Research program of the U. S. Public Health Service has two objectives j one is to allevi- ate the growing pollution problem and the other is to remove dis- solved materials from waste water to make it suitable for reuse. The dissolved materials of interest in this program are those resistant to or totally unaffected by the most modern con- ventional water and waste treatment processes. Such materials are referred to as refractory contaminants. Among the processes being considered for removal of organic or inorganic dissolved materials are the following: Adsorption Electrodialysis Evaporation Extraction Bnulsion Separation Foam Fractionation Freezing Oxidation Ion Exchange Electrochemical Degradation Two report have been issued by the program (73^7^). During 1962 the program did not sponsor any contract research in the State. However, several proposals from firms located in California are under consideration. A-16 RECENT COMMERCIAL PLANTS In order to Indicate the current use of conversion equipment, a partial list of plants initially operated since i960, or currently under construction, are listed in Table A-2. As can be seen, the largest capacity plants are located in foreign countries. A majority of the smaller capacity plants use the electrodialysis process to convert brackish water into potable water. 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O o e - *^^ t- H s r: CM CM CM ^ CM CM ^ « o> o> <» o> W o> O) en •< 5l ^* *" •" "" -1 o ■< 1- X n 31 £ 2 s t5 s 8 H M O V « K e X X X B X ■ 3 ( O •0 o e e >e e o e 9 < e m K It X « o «9 oc fi • e • e o e »- « e • • • CD B o a. < « ^ K • J ^ « Ui « •» L < o X •« w >■ o m !t • X ^ ID m » « < « o s m m » 4 s ^ «J c < 9 to X ■ z •• o ^ 1 ■< X ^ Ml 2 ^ • « •» M •J M. ^ ^ CO w »- K • X •• • i s < • K X X e W •i • < m K ^ o ^ X •< ■* o m o 3 m hg m ^ w ■« e ^ 4 m. s f -1 cr CO m OL. t- > A-20 S YMPOSIUMS AND MEETINGS An increasing niomber of meetings are being devoted to the general subject of removal of dissolved materials from water. The subjects covered include sea and brackish water conversion and waste water reclamation. Some of the more general meetings are briefly described. In most cases , the papers presented at the meetings have been or will be published. At the 1962 spring meeting of the American Chemical Society in Washington, D. C, the Division of Water and Waste Chemistry organized a symposium on saline water conversion. Papers for the full-day program covered such topics as the use of osmotic membranes, the minimizing of scale formation, the design of large electrodialysis equipment, factors affecting the cost of electro- dialytic demineralization, development of freezing processes, new agents for the hydrate process, the effect of vibration on heat transfer and scale formation, phosphate precipitation of minerals from sea water, and flash evaporation utilizing solar energy. The American Chemical Society plans to publish the papers in I963 in its ADVANCES IN CHEMISTRY series. Extended abstracts of the papers were published by the Division of Water and Waste Chemistry (75). On March 28, 1962, the Office of Saline Water held a conference on saline water conversion in Washington, D. C. Papers were presented dealing with basic research problems, with applied research progress, and with the operation of the first three A-21 demonstration conversion plants. The proceedings of the meeting have been published (23). A seminar on advanced waste treatment research was held in Cincinnati, Ohio, on May I5-16, 1962, under the auspices of the Robert A. Taft Sanitary Enginering Center. This research is an activity of the Basic and Applied Sciences Branch, Division of Water Supply and Pollution Control, Department of Health, Education, and Welfare. Much of the basic research work for the activity is performed under contract by independent agencies outside the fed- eral government. The purpose of the seminar was to summarize the work of these contractors, and to supply a forum for the interchange of information and ideas. Processes discussed at the meeting (76) for removal of dissolved materials from waste water included adsorption, foam separation, freezing, electrodialysis, ion exchange and distil- lation. The first European symposium on fresh water from the sea was held at Athens, Greece, from May 31 to June 4, I962. This meeting was organized by the European Federation of Chemical Engi- neers. Of the fifty-four lectures presented, twenty were from representatives of United States Industries or universities. Most of the other papers were presented by leaders in the field of saline water conversion from France, Holland, India, Israel, Japan, United Kingdom, West Germany, and Yugoslavia. Papers presented at the symposium have been published (77). A-22 An Increasing number of papers on saline water conversion are appearing on programs prepared for regular national meetings of scientific and engineering societies. In addition, the Los Angeles Chamber of Commerce made a report on saline water conversion at a half -day meeting in Los Angeles on December 7, 1962. The study was made in conjunction with the chamber's overall study titled "Destination '70 — a Program for Your Future." The report has been published (78). A-23 CURRENT CONVERSION ACTIVITIES Investigations on saline water conversion undertaken by the University of California, sponsored by the Office of Saline Water, conducted by other public agencies and done by private Industry, cover a wide scope from studies of the fundamental prop- erties of water and saline solutions to the development of hardware for commercially proven processes. The Information obtained In some of the fundamental studies may be applicable to distillation, membrane, freezing, or other processes. In the case of studies concerned with a specific phenomena, the results are generally applicable to only one type of conversion process. A brief account of some of this year's highlights is Included. More detailed Information on any specific subject may be obtained from the publications listed In the bibliography.* Distillation Fundamental studies are being made on the material and energy transfer through noncondensable gases, the properties of water in the state of evaporation and boiling mechanism. The mechanism of scale formation is under intensive laboratory Investigation. Once the mechanism is better understood. •^Especially reports by the Office of Saline Water and the University of California. A-24 it may be possible to develop improved ways to reduce scaling tendency in distillation equipment. Methods currently being developed for prevention of scale include removal of scale-forming materials by ion exchange or acid injection, and circulation of a sludge of scale-forming materials. In the latter scheme, the scale-forming chemicals tend to precipi- tate preferentially on the sludge, rather than on the metallic heat transfer surface. Another approach in avoiding scale on heat transfer sur- faces is to use an immiscible liquid for transfer of heat, thereby eliminating the need for a metallic heat transfer surface. Labo- ratory and pilot plant testing are being employed in the investi- gation. Continuing studies are being made on methods to improve heat transfer through metallic surfaces and ways to mitigate cor- rosion in equipment. Thin films and vibrations have been tested this year to improve heat transfer. Dropwise promoters continue to be tested. Testing of materials of construction is being done at the Office of Saline Water Demonstration plants. Fundamental studies of corrosion in saline solutions are being conducted at several laboratories. Hardware for commercial processes is being evaluated and improved by many works in the field. Solar energy applications continue to be studied. The use of large ponds for conversion and salt recovery is under study. Various multiple-effect humidity cycles are being investigated, A-25 Membranes The potential of memlDranes for the production of potable water at relatively low energy consumption is attractive. Much work is being done on the transfer of ions and water through membranes . The studies involved with ion transfer are largely con- cerned with improvement in the electrodialysis process. Im- provements in properties of membranes have been given much attention. The condition under which polarization occurs is being investigated. Since polarization reduces efficiency, the purpose of the work is to improve means of avoiding the phenomenon. Testing and improvement in the electrodialysis apparatus was also continued during the year. Several investigations are under way on various aspects of the mechanism of water transfer through membranes aimed at the development of a reverse osmosis process. Some of the studies involved membrane improvement. Others are more fundamental in- vestiations aimed at an elucidation of the phenomena involved in the transfer of water through the membrane. Freezing The freezing processes have been given increased attention, Processes involving the direct freezing of water to ice and the formation of a hydrate of an organic molecule (for example, pro- pane), are being developed. A-26 I Fundamental laboratory work Involved with clathrate freezing is in progress. Methods of crystal growth are under in- vestigation as a means of improving ice-brine separation, which has been one of the more difficult technical problems involved with the process. The majority of the freezing processes use a direct freezing cycle. Several organic materials have been tested for this application. Other Many other processes and phenomena are under study. Some of the fundamental work include measurements of basic prop- erties of water, thermodynamics of saline solutions, molal entropies of ions and salt transport of plants. Extraction and use of by-products in conversion processes have been given increased attention. The production of a high analysis fertilizer has been proposed. Work is being done with chelating agents (for scale control), absorptivity on porous conductors, and solvation of polyvalent ions in an effort to develop more economical con- version processes. Ion exchange regeneration and applications for pre- treatment to remove scale-forming materials have been studied in the laboratory and pilot plant. Tests are planned at the Office of Saline Water, Roswell, New Mexico, demonstration plant once the plant has been placed in operation. A-27 APPENDIX B APPLICATION OF SOLAR ENERGY TO CONVERSION IN CALIFORNIA B-1 TABLE OF CONTENTS Page INTRODUCTION B-5 DISCUSSION B-5 PROCESS DESCRIPTION B-7 SOLAR COLLECTOR SELECTION B-12 SOLAR ENERGY COST B-27 EVAPORATOR COST B-33 WATER COST B-33 RECOMMENDATIONS B-33 SUMMARY & CONCLUSIONS B-39 Table No . B- 1 Summary of Process Conditions B-13 B- 2 Hourly Summary of Direct and Diffuse Radiation . . . B-17 B- 3 Transmit tance-Absorption Product for Tedlar and Blackened Collector Bottom B-20 B- 4 Solution of Equation 2 (Heat Loss in Btu) B-24 B- 5 Installed Cost of Solar Collector B-28 B- 6 Cost of Bottom Covering B-28 B- 7 Installed Cost of Tedlar Glazing B-29 B- 8 Total Daily Operating Cost of Solar Collector .... B-29 B- 9 Cost of Collected Solar Energy B-31 B-IO Summary of Flash Evaporator Heat and Flow Conditions for Several Terminal Temperature Differences . . . B-34 B-11 Flash Evaporator Capital Cost and Power Requirements B-34 B-12 Flash Evaporator Operating Costs ..... B-37 B-3 TABLE OF CONTENTS (Cont'd) Figure No . Page B-1 Schematic Flow Diagram B-8 B-2 Average Hourly Solar Radiation on a Horizontal Surface August through December . . . B-I6 B-3 Transmlttance-Absorptlon Product for Tedlar Glazing and Black Bottom Surface with Respect to the Angle of Incidence B-21 B-4 Net Heat Gain for Five Layers of Tedlar Glazing . . B-25 B-5 Variation in Net Heat Gain for Five Layers of Tedlar Glazing by Month B-26 B-6 Domains of Glazing Layers for Solar Heat Cost . , . B-32 B-7 Variation in Flash Evaporator Output With Brine Feed Temperature B-35 B-8 Variation in Flash Evaporator Heat Requirements with Brine Feed Temperature B-36 B-9 Water Cost Versus Brine Temperature B-38 B-4 INTRODUCTION In the application of solar energy to saline water conversion the combination of a solar heat collector with a process that is capable of energy reuse may be economically more attrac- tive than direct solar distillation. The multistage flash evapo- ration process can more efficiently utilize the relatively low temperature saline water produced in a flat-plate solar heat col- lector than most other conversion processes. A combination plant was designed to produce annually 3^5 x 10 gallons of water when collecting slightly more than four trillion Btu of heat. A coastal location in Southern California was assumed for the site of this combination plant; consequently, solar inso- lation data, as well as other meteorological data for that area, were used in making calculations for the solar heat collector. The results, however, should be generally applicable to other geo- graphical areas if corrections are applied for the amount of inso- lation received. DISCUSSION The primary purpose of this study was to optimize the cost of water produced in a multistage flash evaporator supplied by brine heated in a solar heat collector. It was, therefore, not possible to select both the plant capacity and the solar col- lector area and still permit optimization. In addition, the brine temperature limitation would be set by an economic evaluation of B-5 both the multistage flash evaporator and the solar heat collector. Evaporator capital and operating cost estimates from a previous study (79) were used extensively in this evaluation. Because the plant output varies with the time of year, it was necessary to determine the output on some logical basis. The basis used was the monthly average of the insolation received at a site along the Southern California Coast. With the available monthly average insolation known, it was possible to determine the net heat that could be captured by a solar heat collector with a given number of glazing layers. In addition, the cost of installing the solar collector was estimated. With the capital cost estimated and the net heat captured calculated, the rela- tive cost of the solar energy on a monthly average basis for several selected brine temperatures could be determined. The plant could then be optimized for a given assumed brine temper- ture and assumed stage terminal temperature difference in the flash evaporator. Although we are interested in the average cost of the water on an annual basis, it was first necessary to determine the approximate plant size. By optimizing the water cost by month for the minimum solar energy cost for several selected brine temperatures, it was possible to determine the point of minimum operating cost for the several assumed evaporator plant capacities. Once this had been determined, it was then possible to calculate the area of solar collector required for each condition. B-6 As might be expected, the optimization was heavily weighed in terms of summer operation when insolation is at a maxi- mum and for the higher brine temperatures when the plant output is relatively greater. PROCESS DESCRIPTION A schematic flow diagram of the plant is shown in Figure B-1. This figure represents the general flow diagram of the multistage flash evaporation process and the solar heat collector system. The process conditions shown on the diagram are typical for operation with a brine temperature of l4o°F. as would be the case during the months of May, June, and August. The sea water is pumped from the inlet sump to the evapo- rator plant where it flows through the tubes of the 20-stage evaporator. As the sea water flows through the stages of the evaporator, it is gradually heated from the temperature of the ocean to 132°F. as a result of the vapor condensing on the outside of the tubes. As it leaves the first stage of the evaporator at 132°F., it is discharged into a canal system and allowed to flow by gravity to the solar heat collector. The sea water then flows through the solar heat collector as shown in Figure B-1. This flow arrangement down the entire length and return permits the flow to take place without piping and with a minimum amount of channels. The sea water travels approximately two miles and requires about 36 hours to complete its flow through the solar heat collector. B-7 yf^ -^ ■^v ^^ -^ \l a . "o o Ul « lO BCUM ««" O u M ■> ■ o • uz 0£ a O - 5 * m y H uj o 2^ 5 =! s: o o * .— ?^ Ui iJU 2 §i B-8 The entire flow is by gravity. As shown in Figure B-1, during August the sea water would be returned to the evaporator at a temperature of l4o°F. It would be Introduced into the shellslde of the first stage of the evaporator vessel which is under a partial vacuum. The flashing process would start at this point. The heated sea water enters the shellslde of the first stage v;lth 33,600 ppm of salt. Since some of the water v;ould be flashed off In each stage, by the time the sea water reaches the lowest temperature stage the salt concentration would be increased by approximately six percent. The sea water flows through the plant at a rate of 17^,000 gpm. Two pumps would be required in the sea water sump to supply this volumetric flow at the head required. Approximately 164,000 gpm would be returned to the ocean as blowdown. The difference of about 10,000 gpm is the product which is also pumped from the system and delivered to the distribution system. The flow system just described is known as a "once- through system." It is customary to employ recycle when operating at higher brine temperatures. In a recycle system the brine is recirculated through the system several times and the blowdov/n con- centration is perhaps twice that of normal sea water. The primary reason for employing recycle is to reduce the cost of the scale control chemicals that are required to prevent scale when operating at higher temperature. In the combination with the solar heat col- lector the economics are different. The economic life of the B-9 plastic glazing material occurs when operating at relatively lower temperatures. Also, operation much above a 150°F. brine temper- ature would require the addition of chemicals for scale control. In order for higher brine temperatures to be an advantageous means of operation, it would be necessary to substantially increase the temperature of the solar collector operation to more than compen- sate for the cost of the scale control chemicals. With the in- creased heat loss at higher temperatures and the reduced life of the glazing, higher temperature operation of the solar collector is not economically justified. The tubeside brine is discharged from the first stage of the evo-porator vessel into a concrete-lined and covered channel which permits the brine to flow into the solar heat collector. The solar heat collector is composed of concrete curbing on 48-foot centers in one direction and 500-foot centers in the other di- rection. The collector is covered with multiple layers of glazing. The sea water flows parallel to the 48-foot sides, that is, the flow path is along the 500-foot dimension. These 500-foot length curbings represent a common wall from one collector to the next. Slots in these curbs permit the brine to flow continuously through the entire mile of collector before reversing direction. Once the brine has reached the end of the solar collector away from the evaporator, it flows into a concrete-lined channel and is diverted back through another series of collectors emerging finally Into a concrete-lined channel at the evaporator end of the collector. B-10 The heated sea water then returns to the evaporator plant and Is Introduced into the shellslde of the first stage of the evaporator through a siphon leg. No pump is required at this point in the system. Actually, as can be seen from Figure B-1, pumps are re- quired to move the sea water through the tubes, and to r«nove the blowdown and the product from the last stage. No other major pumps are required in the operation of the once-through cycle. For the multiple-layer glazing covering the thiclaiess of the glazing was selected as follows: Top layer 4 mils Inside layers 1 rail Bottom layer 3 mils The bottom layer floats on the surface of the sea water. A cross-section of a five-layer glazing covering in the inflated condition is shown below: ^-2'— j— 2'-A 4 MIL TOP LAYER 1 MIL 3 MIL BOTTOM LAYER As indicated in the sketch, the layers are heat-sealed every four feet and air pressure is used to hold the layers apart, The air space between layers imparts desirable heat insulation properties to the covering. The primary purpose of the bottom B-11 • floating layer is to prevent evaporation and condensation between the water surface and the glazing, A summary of the process conditions, typical for August, is tabulated in Table B-1. These conditions are typical of the operation only since the output from day to day depends upon the amount of solar insolatibn received. A slightly higher output at a higher brine temperature would be expected in July. Conversely, lower operating temperatures and output would be expected during the remaining months of the year with a minimum occurring during December and January, when the amount of solar insolation captured by the still is at a minimum. SOLAR COLLECTOR SELECTION The most complete Information on the amount of total radiation received in Southern California is available from the U, S, Weather Bureau in Los Angeles, Therefore, the monthly aver- age of solar radiation received in the Los Angeles area during a ten-year period was used as a basis for determining the insolation available at a site in the San Diego area. Cloudless day radiation was calculated from the following relationship: Q = Qo (a + bS) (1) where Q = Quantity of solar energy received on a unit area of horizontal plane at the earth's surface per unit of time. B-12 TABLE B-1 SIMIARY or PROCESS CONDITIONS* (30F Tehmihai Tempehatuiie Oiffehince) NUMIE* OF STASES Maxinum Se* W»te« Temperatuhe, °F Se* Water TEnPEHATUitE to Solar Heater, °F Temperature Rise in Solar Heater, "F Blowoowr Temperature 'F Product Temperature, 'F Sea Water Flow, GPM Product, GPM Sea Water Salt Concentration, PPM Slowdown Salt Concentration, PPM Velocity of Sea Water in Tudes, Ft/sec Solar Collector Area, Acres Number of Layers of Glazins Solar Collector Heat Duty, Bth/hr x 10 Solar Collector Net Heat Gain, Btu/(Ft2) (day) Sea Water Velocity in Collector, Ft/Sec Residence Time of Sea Water in Collector, Hours 20 140 132 8 80 78 174,000 10,200 33,600 35,700 6 595 5 680 630 0*06 TO 0.1 36 a) Typical for operation ourinc Auoust, B-13 Qq = Cloudless day radiation. Quantity of solar energy received on a unit area of horizontal plane at the earth's surface per unit of time during cloudless days. S = Number of hours of sunshine instrumentally recorded divided by the number of hours of possible sunshine, a, b = Constants. Based on the cloudless day radiation calculated for Los Angeles, the expected radiation received in San Diego was calculated using sunshine data published by the Weather Bureau in San Diego. The mean solar radiation received in Los Angeles varies from a low of 856 Btu/(Ft )(Day) in December to a high of 2,370 in July. Corresponding figures calculated for San Diego are 843 to 2,155^ respectively. Since the angle of incidence of radiation changes con- tinuously with relation to a horizontal surface, it is necessary to determine the amount of heat captured by a solar collector on an hourly basis. The data of L*6f (80) in which he presented the fraction of total daily radiation received on a horizontal surface each hour by month was used in this study. It was determined that the effect of the latitude dif- ference between Los Angeles and San Diego on the insolation re- ceived amounted to a negligible correction during the summer months; however, correction of several percent was indicated for B-14 the six winter months from October through March. Appropriate corrections were applied to the Insolation data to obtain the final calculated values for San Diego. The result of these calcu- lations are shown graphically In Figure B-2 for the months of August through December. The other months have curves with a similar shape. The solar energy received on a horizontal surface as shown In Figure B-2 Is composed of direct and diffuse radiation. The Weather Bureau measurements were made with an Eppley pyrhell- ometer (81,82), which measured the total radiation falling on a horizontal surface. Since the incident angle of diffuse radiation does not vary with time of day and year as it does with direct radiation, it was necessary to determine each component separately. Several references were found which gave an estimate of the percent of diffuse radiation (80,83,84,85). Typical values for three solar times in July are itemized below. Values used in this study for each month by hourly solar time can be derived from data presented in Table B-2. Time from Solar Noon Hours Diffuse Radiation Percent 0.5 17| 2.5 18, 4.5 20| With the total insolation determined and the percent of diffuse radiation established, it was possible to calculate the quantity of direct and diffuse solar radiation available on a monthly average basis for each hour of solar time. The results B-15 FIGURE B-2 AVERAGE HOURLY SOLAR RADIATION ON A HORIZONTAL SURI^^ACE AUG. THRU DEC. (SOUTHERN CALIFORNIA COSTAL AREA) 250 200 X ISO z o a < lU o < UJ > 100 so / AUG. \ ' 1 '2 AUG. 19S8 BTU/FT'^) (DAY ) / '/ SFP-T OCT. <^ CT. 129 OV. 107 EC. 884 3 3 II It II / // / / NOV. DEC. \ \ \ N \ A ^ / \ ^ \ / / / \ A ^ / \ 6-7 7-8 8-9 9-10 10-11 11-12 12-1 SOLAR TIME, HOURS 1-2 2-3 3-4 4-S B-16 TABLE B-2 Hourly Suhhary of Direct ahs Diffuse Rabmtior (Monthly Averaoc Basis) SOI AR TIME Total 1i-1i ib-H 9-10 84 M 6-y Btu MOUT H 12-1 1-2 2-3 )(mr1"^ 4-6 5-6 Ft 2 Day INSOLATIOR, Btu/ (Ft2 Jar t 107 37 29 20 9 . 274 94 71 38 9 . 638 T» 149 131 100 58 18 - 912 Feb I . 53 48 39 27 16 . 366 D 1« 127 99 63 24 . 910 T 195 175 138 90 40 - 1276 ruR 1 ^3 39 33 25 17 6 326 D 197 178 144 99 51 9 1356 T 240 217 177 124 68 15 1682 Apr I 40 38 32 25 19 9 326 1 193 171 147 109 63 24 1414 ■f 233 209 179 134 82 33 1740 May'i • ^ 4i ^5 i7 19 10 356 216 192 159 120 76 29 1584 T 262 233 194 147 95 39 1940 JUR 1 44 40 35 29 22 16 372 D 208 190 161 127 89 49 1648 T 252 230 196 156 111 65 2020 JVL 1 • 45 41 37 31 26 19 398 n 2^5 196 170 139 99 59 1766 J 260 237 209 170 125 78 2154 Au« 1 45 40 35 28 21 12 362 215 191 161 121 77 33 1596 -r 260 231 196 148 98 45 1958 itr 1 D ^ i9 33 26 19 8 336 197 175 146 106 59 18 1402 T 240 214 179 132 78 26 1738 Oct I B 35 33 26 21 12 — 254 D 160 145 113 71 33 • 1044 y 195 178 139 92 45 - 1298 Nov 1 B *7 42 35 23 13 . 320 D 124 109 84 47 15 - 758 T 1" 151 119 70 28 — 1078 DEC 1 B 41 37 28 20 7 - 266 D lor 93 67 35 7 • 618 T 148 130 95 55 14 - 884 A) l| Diffuse Ihsmatish s) Iq Direct Insolatior e) Ij Total Ihsolatioh B-17 are shown In Table B-2. The next step was to determine how much of this available energy could be captured by a solar heat collector. Preliminary calculations of the transmission of solar radiation through multiple layers of glazing (glass and plastics) Indicated the superiority of Tedlar* over the others; consequently, the detailed calculations were made assuming a Tedlar glazing. The calculations were based on the work by Hottel (86). The trans- mittance of the surface was calculated from the following equation developed by Hottel: 7- = 1-r " 1 + (2n-l) r where T - Overall transmittance of n layers of nonabsorbing glazing, r = Surface reflectivity of glazing. n = Number of layers of glazing material. The transmittance of a single layer of Tedlar as a function of the incident angle of the sun was obtained from a chart presented by Edlin (87) . This measured value of transmittance is the net amount of energy transmitted by the glazing, taking into account both reflection and absorption losses. With the single layer transmittance known, the transmittance of multiple layers was calculated in accordance with Hottel 's equation. The absorptivity of a blackened surface is a function of the angle of incidence, and was based on data presented by Hottel (86) and Yellott (88). The product of the transmittance and *duPont registered trademark. B-18 absorptivity of the glazing as a function of the number of layers of glazing and Incidence angle Is shown In Table B-3 for three, four, and five layers of Tedlar glazing. Figure B-3 shows the transmlttance-absorptlon variation with the angle of Incidence for one to seven layers of Tedlar glazing. Values read from Figure B-3 were used to calculate the direct and diffuse solar radiation captured by the solar heat collector. The angle of Incidence Is a function of time of day and year for the direct radiation. Appropriate values were used to read the transmlttance- absorptlon product from Figure B-3. The product for the diffuse component of the radiation Is a value corresponding to an angle of Incidence of 58°F. (80,89). The total Insolation captured by five layers of Tedlar glazing was calculated to be 1,439 Btu/(Ft ) (Day) in July, and 465 in December. Intermediate values were determined for the re- mainder of the months. The heat that is transmitted through the glazing surface and absorbed by the collector is available for heating the brine. The useful amount depends on the fraction that is not lost to the atmosphere or ground. The calculation of heat losses from solar collectors has been treated by several investigators (86,90,91^92). In this study the equation developed by Hottel (86) which neglects the transparency of the glazing in the infrared portion of the spectrum was used. The relationship, although somewhat complicated, can be B-19 TABLE B>^ TRANSMITTANCE-AB50RPTI0N PRODUCT FOR TEDLAR AND BLACKENED COLLECTOR BOTTOM NuntCR llCIOCNCC OF Ancle TRtmniTTAiicc AaSORPTIVITV Product' La vent DceiitE* or Bottom 3 0.876 0.960 0.833 20 0.871 0.958 0.826 40 0.832 0.939 0.773 60 0.755 0.880 0.658 80 0.182 0.657 0.118 4 0.840 0.960 0.798 20 0.836 0.968 0.793 40 0.788 0.939 0.733 60 0.703 0.860 0.612 80 0.143 0.657 0.093 5 0.810 0.960 0.770 20 0.803 0.958 0.762 40 0.749 0.939 0.696 60 0,659 0.880 0.674 80 0.119 0.657 0.077 «) RitucEV OH PiRcmr roR rirt or riazihc surface. B-20 FIGURE B-3 TRANSMITTANCE-ABSORPTION PRODUCT FOR TEOLAR GLAZING AND BLACK BOTTOM SURFACE WITH RESPECT TO THE ANGLE OF INCIDENCE I- i o Q. z o a. m o (D < I lU u z < I- 1 - ■< 9. 800 N •< o ■< lU Ul 600 400 200 ^ ^ c^^"^^ N h ^ \^^ \^ ^v^ ^^^ *^ ^ \ ^ ^^^ ^"^ \^^ ^ :^ >- ^ 100 no 120 130 COLLECTOR TEMP., °F 140 150 B-25 FIGURE B-5 VARIATION IN NET HEAT GAIN FOR FIVE LAYERS OF TEDLAR GLAZING BY MONTH 1200 1000 < Q ^ 800 600 3 »- CD < < UJ X 400 bi 200 B-26 curve during the spring months can be explained by the variation in the cloud covering during that time of year along the Southern California Coast. SOLAR ENERGY COST A preliminary calculation indicated that a solar collector area of approximately 25 million square feet would be required to capture sufficient heat to operate the multistage flash evaporator shown on Figure B-1. Since a large number of collector units would be required, an estimate of installing 1,000 units containing 24 million square feet of collector surface was made. With such an estimate the cost per unit area and the amortized cost per unit area could be determined. For a variation of no more than ten percent in the collector area the unit cost would remain the same. In this- way, the optimization could be made without the necessity of making separate estimates of each assumed collector installation. Table B-5 lists the items of the solar collector and the installed cost of each with the exception of the plastic bottom covering and the glazing which are treated separately. Table B-6 shows the cost of the polyethylene bottom covering. The installed costs of the Tedlar glazing for two to seven layers, including the heat-sealing cost and installation charges, are given in Table B-7. The summary of the total dally operating cost for the solar collector is given in Table B-8, Before the estimated cost of vjater from a multistage flash evaporator utilizing solar heated brine could be made, an estimate B-27 TABI£ B-5 installed Cost of Solar (1000 Units U8« X Collector 500' b Amortized Cost ^/(Unit)(Day) 5.50 Installed Cost Dollars 280,000 Estimated Life Years Capital Cost $/nnit 280 Excavation U8 Concrete and Paint** 1,370,000 U8 1,370 26.93 Plastic Inserts and Glazing Holddown 200,000 8 200 12.38 Buggies 60,000 2U 60 1.6U Piping® 100,000 2U 100 2.73 Total 2,010,000 U9.18 a) Does not include plastic ground cover or glazing. b) Money at li^ per annum. c) Amortized over plant life of kS years, annual painting is part of operating expense. d) Required to span collector for washing glazing and general maintenance work. e) Eresh water system for washing the glazing. TABI£ B-6 Cost of Bottom Covering b Collector Material Cost° $ 600 d Heat Sealing Cost ko Installation Cost 700 Total |1,3U0 Unit Cost 5.58|^/Ft^ Amortized Cost 82.92^/(Unit)(Day) a) Blackened polyethylene. b) One collector unit is U8 ft. x 500 ft. c) 10 mil polyethylene, $0,50 per lb. d) 2000 lineal feet at $0.02/ft. e) Includes cost of sealing bottom to the plastic inserts (500 inserts per collector). f) 8-year life, h% per annum, equivalent to lU.853^ per annum. I B-28 Installed TABI£ B-7 Cost of Tedlai • Glazing No. Layers Material Cost $ 3,597 Fabri- cation Cost $ 212 Instal- lation Cost $225 Total Fabricated Cost Am ortized Cost Unit) (Day) 2 $ U,03U 2U9.62 3 1|,111 382 225 1;,718 291.95 k U,625 828 225 5,678 351. 3U 5 5,138 1,083 225 6,)4i;6 398.38 6 5,652 1,7 8U 225 7,661 U7U.06 7 6,166 2,12U 225 8,515 526.91 a) Eight years life, U% per annum. TABI£ B-8 Total Daily Operating Cost of Solar Collectors (Unit Collector I|0' x 500') NOo Layers Tedlar Glazing Cost Other Collector Costs ,l/(Unit)(Day) ,l/{Unit)(Day) 2 2U9.62 203.03^ 3 291.95 203.03 h 351. 3U 203.03 $ 398.88 203.03 6 li7U.06 203c 03 7 526.91 203.03 Total Daily Collector Cost — */M^--'^^ -- ■■ ■ „f 7?Eg" U.53 U.95 5.51; 6.02 6.77 7.30 0.0189 0.0206 0.0231 0.0251 0.0282 0.030U a) Money at h% per anmira. b) U9.18 from Table 5j 82.92 from Table 6, plus U5.93 for real estate and 25.0 for operation and maintenance labor. B-29 of the cost of the recovered energy was required. This estimated cost of the collected solar energy was determined in cents per million Btu. This information is summarized in Table B-9 for three to seven layers of glazing and six assumed brine tempera- tures between 100° and 150°. The next heat available for each selected condition is also listed in Table B-9. An examination of Table B-9 will reveal that at con- stant temperature, for some of the conditions presented, the quantity of heat captured actually decreases with an increase in the number of glazing layers. See, for example, 110°F. brine temperature in July, where the maximum heat captured is with five layers of glazing. This simply means that the incremental heat loss due to reflection and absorption by the added layer of glazing, is greater than the heat saved as a result of one more layer of glazing acting as an additional heat insulator. The solar heat cost in cents per million Btu is graphi- cally presented in Figure B-6. The domains of glazing layers are indicated on the chart. At 3°F. terminal temperature difference the brine temperature for minimum water cost is between 130° and 150 °F. As can be seen from Figure B-6, during the six months from April through September, the optimum falls within the domain of five layers of glazing. Since the majority of the plant output occurs during this period, the optimization will be heavily weighed in favor of five layers of glazing. B-30 a T5 0) +> O a> o o o o o ol Ul g^ ^I 01 ^I O (0 Eh »J • • • • • CO OS H -^ r- H iH CM CM C\J \AOn O rHOO _:3-CNCOXAH r-i iH iH rH rH iH iH iH pH rH • • • • • O cvj-^r- O CM CM CM CM fn CM CMvO 0^00 O Xf\_::t CM cJn O O O O CJs rH iH H rH lACMvC O <^ • • • • • vo c^ o\-^ r^ CM CM CM r^ro t~.\r\^ CM H C--CO 00 00 00 r^c^Os CM\A • • • • • f^ r^O 000 vO CJn CM CM On C*Mr\t-ICMO t^ r- -::t r- 00 rH c^ cnMD XA 1AC3S-^(HCM On 00 O r- <*> • • • • • «:3^vO CJN_=fH lACn CMVO NO r- CJ\ rH iH CN CO fnH c- iH H O^MD On CM CM CM CM CM OlrvtAXAOO f- r-OO C--_d' CTn O O O O -d^-^NO c;n cm CM CM CM CM rr\ \rMAO O r- tn 0-\XA\A CM 00 On On (?N On -=t r-\ rr\ t~- O "lAOlAO O O O^IAIAIA NO c«- r- t>- P- 0| vONOvOVNCM CMOnnOOOnO -_;tOO ONt- t^ CTn CTn On CK 00 On On NO CJN • • • • • ■LA 00 00 H r^ -no cm rH CM 0-> W (0 iH O CO •o •p o O -P CO ID K -P - CA-^VAnO c- ^ \ / r / / (MAY (JUNE (AUG. ^® X /^ %< ^ JULY ^^ ^^ ^X^ ^-mTiiZ-j ^^ -^ 100 110 120 130 BRINE TEMPERATURE, °F. 140 150 B-32 EVAPORATOR COST Data developed in a previous study (79) of evaporator economics was largely used in this analysis. A summary of the multistage flash evaporator heat and flow conditions for several terminal temperature differences is presented in Table B-10. The estimated capital costs are presented in Table B-11. The variation in the evaporator output with brine temperature is presented in Figure B-7 and the variation in the evaporator heat requirement with brine temperature is presented in Figure B-8. The summary of the flash evaporator operating costs is presented in Table B-12. WATER COST To the evaporator cost, must be added the cost of col- lecting the energy in the solar heat collector. The variation in the water cost for the time of year and brine temperature is shown graphically in Figure B-9 for a 3°F. terminal temperature differ- ence, which was established to be about optimum for this design. The cost curves shown in Figure B-9 represent all costs associ- ated with both the evaporator and solar heat collector. The weighted average cost of water is $1.10 per 1,000 gallons. RECOMMENDATIONS The ideal glazing would be a material that transmitted all of the solar energy into the collector and, at the same time, reflected the long wave reradiation from the collector. Research B-33 TABLE B-10 Summary of Flash Evaporator Heat and Flow Conditions for Several Terminal Temperature Differences (20-Stage Plant; TTD 1.5 a 3.0 k.S Brine^ Temp, 100 110 120 130 11^0 150 100 110 120 130 lliO 150 100 no 120 130 lliO 150 Solar Heater Duty /• Btu/Hr X 10 305 365 U30 1*90 553 612 335 U25 510 595 680 765 335 U31 515 585 660 735 Plant Capacity GPD X 10~° U.9 7.35 9.8 12.25 li4.7 17.1 h.9 7.35 9.8 12.25 llt.7 17.1 k.o 6.0 8.0 10.0 12.0 llt.O a) Stage terminal temperature difference b) Inlet temperature to first stage c) Capacity the same for TTD of 1,5° and 3.0** F since the number of condenser tubes is the same for each. TABUS B-11 Flash Evaporator Capital Cost and Power Requirements (20-Stage Plant) TTD , °F lo5 3.0 U.5 Capital Cost x 10 , $ 20.7 15.5 11.3 2 Condenser Area, Ft li, 150, 000 2,620,000 1,580,000 Pumping Horsepower 22,700 18,300 i3,U5o a) Stage terminal tenperature difference. b) Total of all installed pumps including pump and motor efficiences. Based on velocity of 6 ft/sec in condenser tubes for sea water pump. B-34 FIGURE B-7 VARIATION IN FLASH EVAPORATOR OUTPUT WITH BRINE FEED TEMPERATURE (3°F TERMINAL TEMPERATURE DIFFERENCE) ISO / / / / IL 140 e ee UI H / / RINE TEMPERATURE FROM SOLAR HEA / / / / / / / / 10 1 lU / 100 / 8 10 12 PLANT OUTPUT, GPDxIO 14 16 -6 18 20 B-35 FIGURE B-8 VARIATION IN FLASH EVAPORATOR HEAT REQUIREMENTS WITH BRINE FEED TEMPERATURE (3°F TERMINAL TEMPERATURE DIFFERENCE) 150 140 - lU 0£ 130 Ui Q. 2 111 a lU 111 u. a O »- < o a. < > 120 110 100 300 400 500 600 700 EVAPORATOR HEAT REQUIREMENT, BTUxlO'^ 800 B-36 TABLE B-12 Flash Evaporator Opcratik Costs (Dollars Per Strcaii Day) rro, OF Electrical EniRev Supplies ah minEHANci Material Ope RAT (Nc La 10* Haiktenahce Labmi Payroll Extras overheab Amortization Insurance EVAPORATOR TOTAL Interest onUorkinc Capital 1.6 3.0 4.5 4410 3310 2420 ITS 88 70 191 191 191 130 66 52 48 39 36 43 43 43 4152 3109 2267 60 45 33 9209 6891 5112 64 48 36 B-37 FIGURE B-9 WATER COST VERSUS BRINE TEMPERATURE FOR 3**F. TERMINAL TEMPERATURE DIFFERENCE 220 200 180 Z o -i < o S 2 160 Oi m a. z lU u 140 O u < 120 100 80 \ \\ wN V ^ -.^ OCT. MAR. \ \\ i^ (APR. (SEPT. ^^^^ (MAY (JUNE (AUG. JULY 100 110 120 130 140 ISO BRINE TEMPERATURE, "F. B-38 with glazing materials to improve the transmittance and, at the same time, reduce the reradiation losses could improve the eco- nomics of a solar heat collector. It is, therefore, recommended that these two avenues of investigation be considered by re- searchers in this field. SUMMARY AND CONCLUSIONS 1. The economics of a combination of sea water evaporator-solar heat collector have been examined on the basis of current technology using I96O construction costs. A multistage flash evaporator was selected for the sea water evaporator. A Tedlar covered solar heat collector was selected to heat the brine used In the evaporator. 2. Approximately 10,600 acre-feet of potable water could be produced during a ten-month operating year utilizing nearly one square mile of solar heat collector surface. 3. The total capital cost of the plant was esti- mated to be approximately 26 million dollars, 60 percent of which was the cost of the evaporator and its aux- iliaries. The remaining 40 percent for the solar heat collector was divided into 26 percent for the glazing, 6 percent for the plastic bottom, and 8 percent for the collector Installation, B-39 4. During a ten -month operating year the average water cost for the plant was estimated to be approxi- mately $1.10 per thousand gallons, 5. During a ten -month operating year the solar heat collector would capture slightly more than four trillion Btu. 6. Considerable improvement in the materials used for glazing will be required before the reflection and reradiation losses can be reduced sufficiently to make this means of obtaining heat generally economi- cally attractive. B-40 APPENDIX C BIBLIOGRAPHY C-1 ^ APPENDIX C Bibliography 1. Department of Water Resources Bulletin No. 93 "Saline Water Deminerallzation & Nuclear Energy in the California Water Plan." (December i960) 2. United States Department of the Interior SPECIFICATIONS I98 for a 1,000,000 gpd Multistage Flash Distillation Sea Water Conversion Plant at San Diego, California. (October I8, i960) 3. Office of Saline Water Annual Report for I96I. (January I962) 4. 6. 8. 9. .10, 12. % Department of Water Resources "The Sea Water Conversion Plant at San Diego, California." (March 1962) Stetson, C. L. DWR "Statement on San Joaquin Valley Drainage Investigation before California Water Commission, Coronado, California." (November 9, I962) Ionics, Incorporated, Brochure (undated), "The Buckeye Plant." Baker, R. A., "Design, Operation and Results of the Largest Flash-Type Seawater Conversion Plant and Its Effect on Future Conversion Plants, " American Power Conference, March 28, I962, Chicago. Hammond, R. P., NUCLEONICS 20; 45-49 (1962). Sesonske, A. and Hammond, R. P., "A Preliminary Evaluation of Fast Oxide Breeder Reactors for Sea Water Conversion," Los Alamos Scientific Laboratory, LA-2733 October 19, I962. Los Angeles Times, Nov. 22, 1962, Part 1, page 8, "Giant Atom Power Plant Under Study," 11. Anonymous - NUCLEONICS 20, 1? (1962). Fluor Corporation "Feasibility Study of a Combined Solar Heater Multistage Flash Evaporator for Sea Water Conversion, " DWR Agreement No. 25087O August i960. Brice, D. B., "Saline Water Conversion by Flash Evaporation Utilizing Solar Energy," Advances in Chemistry Series No. 38 Saline Water Conversion II - American Chemical Society, Washington, D. C, 1963. C-3 Bibliography (cont'd) 14. "Saline Conversion and Nuclear Energy," A Report of the Assembly Interim Committee on Water Subcommittee on Saline Conversion and Nuclear Energy, Vol. 26 No. 7, January 7, 1963. 15. Budget Act of I962, State of California. Item 93. 16. University of California Water Resources Center, Contribution No. 54, "Saline Water Research - Progress Summary, June 1962." (July 1962) 17. University of California Water Resources Center, Contribution No. 60 'Berkeley Progress Report for the Year Ending June 30, 1962." (August 1962) 18. Cary, E. S., H. J. Ongerth and R. 0. Phelps - JOURNAL AMERICAN WATER WORKS ASSOCIATION ^, 585-593, I960. 19. Phelps, R. 0., WATER WORKS ENGINEERING, 111 , 752 (1958). 20. Anonymous - WATER WORKS ENGINEERING, 112, 299 (l959). 21. Phelps, R. 0., "Operating Experience of Electrodlalysls Process at Coallnga." Colloquium of Desalting of Water, California Institute of Technology, May 5-6, i960. 22. United States Department of the Interior NEWSRELEASE PN-10028- 62. (June 25, 1962) 23. Office of Saline Water "Proceedings of the Conference on Saline Water Conversion," Washington, March 28, 1962. (PB-181322) 24. United States Department of the Interior NEWSRELEASE PN-3O-62. (January 4, 1962) 25. Hearings before a Subcommittee of the Committee on Appropri- ations, House of Representatives 87-2, Department of Interior and Related Agencies Appropriations for 1963, page 848. 26. United States Department of the Interior NEWSRELEASE PN-16977-62. ^ (October 23, I962) 27. United States Department of the Interior NEWSRELEASE PN -22043-63. (January 31, 1963) 28. Loeb, S., "Sea Water Demlneralization by Means of a Semi- permeable Membrane," University of California Water Resources Center Contribution No. 52.- (June I962) C-4 Blbllop;raphy (cont'd) 29. Loeb, S., "Sea Water Demineralizatlon by Means of a Semi- permeable Membrane, " University of California Water Re- sources Center Contribution No. 58. (August I962) 30. United States Department of the Interior NEWSRELEASE PN-II859- 62. (July 23, 1962) 31. United States Department of the Interior NEWSRELEASE PN-IO55II- 61. (December 22, I961) 32. Thompson, W. S., Woodward, T., Shrode, W. A,, Baird, E. D., Oliver, D. A., "Feasibility, Research and Analysis of Heat Exchange Systems Without Metallic Heat Exchange Surfaces and Laboratory Study of Single Stage Vapor Reheat Distil- lation, " United States Department of the Interior, Office of Saline Water Research & Development Progress Report No. 63 (PB-181299 April 1962). 33. Office of Saline Water "A Standardized Procedure for Estimating Costs of Saline Water Conversion." (March I956) 34. Office of Saline Water - Private communication, (Nov. 27, 1962) 35. AERONUTRONIC NEWS - Vol. 3, No. 39. (December 3, I962) 36. "Saline Water Research - June 1962 Progress Summary, " Univer- sity of California Water Resources Center Contribution No. ^h. (July 1962) 37. "Saline Water Research - June I96I Progress Summary," Univer- sity of California Water Resources Center Contribution No. 38. (September 196I) 38. University of California at Los Angeles, Engineering Reports Nos. 1376 (1950), and 5^-11, 5^-51, 5^-96. (195^) 39. McCutchan, J. W., "Sea Water Demineralizatlon: Reverse Osmosis Pilot Plant," University of California at Los Angeles, Engineering Report No. 60-19. (March i960) 40. "Quarterly Progress Report, March 1-May 3I, 1959," University of California at Los Angeles, Engineering Report No. 59-46. (May 31, 1959) 41. Hassler, G. L. & McCutchan, J. W., ADVANCES IN CHEMISTRY Series No. 27, 192-205. (i960) 42. Stanford Research Institute Private communication Dec. 6, I962. C-5 Blbllop;raphy (cont'd) 43. Williams, J. S., NAVY CIVIL ENGINEER - ^, No. 11, 44-45. (1962) 44. Loeb, S., "Sea Water Demineralizatlon by Means of a Semi- permeable Membrane," University of California Water Resources Center Contribution No. 66. (December I962) 45. Bruce, A. W. - COMBUSTION 26, No. 6, 65-68. (195^) 46. Bruce, A. W. - JOURNAL AMERICAN WATER WORKS ASSOCIATION - 5^ 11-17. (1961) 47. "Preliminary Design Study of an Optimum Nuclear Reactor- Saline Water Evaporator Process," PB-I6IOIO (Sept. 1959), United States Department of the Interior, Office of Saline Water, Research & Development Report No. 34. 48. Leitner, G. F. - ELECTRICAL WORLD, 154 , No. 13, 66-69, 123. (September 26, I960) 49. Whistler, R. E. - ELECTRICAL WEST, 123 . No. 3, 84-86. (September 1959) 50. Whistler, R.E. - ELECTRICAL WEST, 126, No. 5, 68-69. (May 1961) 51. Whistler, R. E., "Operation of the Sea Water Distillation Pilot Plant Mandalay Steam Station," AMERICAN POWER CON- FERENCE, Chicago, March 21-23, I96I. 52. Leitner, G. F., "Sea Water Conversion, By-Product of Power," AMERICAN POWER CONFERENCE, Chicago, March I96O. 53. ROCKETDYNE NEWSRELEASE No. R-21. (May 5, I961) 54. ROCKETDYNE SKYWRITER, Vol. XXI, No. 38. (September 22, I96I) 55. Wiegardt, H. F., "Saline Water Conversion by Freezing," Office of Saline Water Research & Development Progress Report No. 4l PB-I61906. (August 1960) 56. Office of Saline Water Specifications No..24l "For a 250,000 Gallon per Day Freeze Demineralizatlon Sea Water Conversion Plant at Wrightsville Beach, North Carolina. (May I962) 57. Carr, James K., Statement Before the Committee on Interior and Insular Affairs, House of Representatives, Washington, D.C. (February 11, I963) C-6 Bibliography (cont'd) 58. Office of Saline Water Specifications No. 195 "For a One Million Gallon per Day Long Tube Vertical Evaporator Multiple-Effect Distillation Plant at Freeport, Texas." (May i960) 59. Chirco, A. N. & Dunn, J. T., "Sea Water Conversion Plant, Preeport, Texas, " American Society of Civil Engineers, Phoenix, Arizona, April 1961. 60. Cywin, A., Jebens, R. H., Dodd, G, D. & Singleton, H. D., "The First Municipal Sea Water Conversion Plant in the United States," American Society of Mechanical Engineers, Houston, Texas, October 196I, 61. Guccione, E. - CHEMICAL ENGINEERING, 6£, 102-104. (Nov. 26, 1962) 62. Department of the Interior and Related Agencies Appropriation for 1963. Hearings Before a Subcommittee on Appropriations, House of Representatives 87-2, pages 35 "36, (January 17, 1962) 63. Office of Saline Water Specifications No. 212 "For a 250,000 Gallon per Day Electrodialysis Brackish Water Conversion Plant at Webster, South Dakota," (September i960) 64. Chopey. N. P. - CHEMICAL ENGINEERING, 6£, 104-106. (May 28, 1962) 65. Seko, M. - DECHEMA -MONOGRAPHS Vol. 47, Part II. 66. United States Dept, of the Interior NEWSRELEASE PN-17518-62, (October 31, 1962) 67. Office of Saline Water Specifications No. 224 "For a 1,000,000 Gallon per Day Forced-Circulation Vapor-Compression Brackish Water Conversion Plant at Roswell, New Mexico," (October 1961) 68. Dodge, B, F, & Eshaya, A, M,, "Economic Evaluation Study of Distillation of Saline Water by Means of Forced-Circulation Vapor-Compression Distillation Equipment, " Office of Saline Water Research & Development Progress Report No, 21, (PB-161395 undated) 69. Lebels, E. H. & Pechenick, W., "Forced -Circulation Vapor- Compression Distillation for Desalination of Water, ' American Society of Mechanical Engineers, Houston, Texas. (Oct. 1961) C-7 Bibliography (cont'd) 70. Anonymous - CHEMICAL ENGINEERING, 6£, 7^-76. (January 22, I962) 71. United States Department of the Interior NEWSRELEASE PN-5768- 62. (April 6, 1962) 72. United States Department of the Interior NEWSRELEASE PN-IOO83- 62. (June 21, 1962) 73. ADVANCED WASTE TREATMENT RESEARCH-1 "Summary Report, June i960- December I961, " Robert A. Taf t Sanitary Engineering Center Technical Report W62-9. (May 1962) 74. ADVANCED WASTE TREATMENT RESEARCH-2 "Preliminary Appraisal of Advanced Waste Treatment Processes, " Robert A, Taf t Sanitary Engineering Center Technical Report W62-24. (September I962) 75. Preprints of Papers presented at l4lst Meeting Amerlcal Chemical Society, Division of Water & Waste Chemistry, Washington, D. C. (March 1962) 76. Seminar on Advanced Waste Treatment Research by U. S. Public Health Service, Robert A. Taft Sanitary Engineering Center, Cincinnati, Ohio. (May I962) 77. Dechema-Monographien Volume 47> Parts I and II, Frankfurt Am Main, West Germany. (1962) 78. "Saline Water Conversion," Los Angeles Chamber of Commerce. (December 7, I962) 79. Brlce, D. B. and Townsend, C. R., "Sea Water Conversion by the Multistage Flash Evaporation Method" p. 147 Advances in Chemistry Series No, 27, American Chemical Society, Washington, D. C. (i960) 80. liof, G, 0. G., "Design and Evaluation of Deep-Basin, Direct Solar Heated Distiller for Demlnerallzatlon of Saline Water' To Office of Saline Water, Contract No. 14-01-001-74. (April 1959) 81. Bulletin No. 2 - The Eppley Laboratory, Inc., Newport, Rhode Island. 82. Kimball, H. H., "Pyrhellometers and Pyrhellometric Measure- ments," Circular Q (W.B. No. IO51), Solar Radiation In- vestigations Section, U. S. Department Agriculture, Weather Bureau. (November 1931) C-8 Bibliography (cont'd) 83. Heating, Ventilating and Air Conditioning GUIDE. The American Society of Heating and Ventilating Engineers 30th Edition (1952), New York. 84. Hand, I. F., "Insolation on Clear Days," Heating and Venti- lating, hXi 92. (January 1950) 85. Jordon, R. C. and J. L. Threlkeld, "Solar Energy Available for Heating In the United States," Heating, Piping, and Air Conditioning, 2^, ill. (December 1953) 86. Hottel, H. C. and B. B. Woertz. "The Performance of Plat- Plate Solar-Heat Collectors. Transactions American Society of Mechanical Engineers, 64, 91. (1942) 87. Edlln, F. E., "New Materials for the Utilization of Solar Energy," presented at the International Colloquiiim on the Thermal Applications of Solar Energy in the Plelds of Re- search and Industry. Montlouis, Pyrenees - Orientales, France. (June 1958) 88. Yellott, J. I,, "Power from Solar Energy," Transactions American Society of Mechanical Engineers, -22* 1349. (1957) Hottel, H. C. and A. Whilller, Transactions of the Con- ference on The Use of Solar Energy, The Scientific Basis Volume II, Thermal Processes Part 1, Section A Flat-Plate Collectors. "Evaluation of Flat-Plate Solar-Collector Performance, " page 78, Tucson, Arizona. (October 31- November 1, 1955) 90. Threlkeld, J. L. and R. C. Jordon, "Utilization of Solar Energy for House Heating," Heating, Piping and -Air Conditioning, 26, 193. (January 1954) 91. Parmelee, G. V. and W. W. Aubele, "Radiant Energy Emission of Atmosphere and Ground, " Heating, Piping and Air Conditioning, 2^, 120 (November 1951). 92. Bliss, Jr., R. W., "The Derivations of Several 'Plate- Efficiency Factors' Useful in the Design of Flat-Plate Solar Heat Collectors," Solar Energy, ^, 55. (December 1959) 93. "Study and Field Evaluation of Solar Sea Water Stills," Quarterly Progress Reports 1-7 to the Office of Saline Water by Battelle Memorial Institute. C-9 I K THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW RENEWED BOOKS ARE SUBJECT TO IMMEDIATE RECALL JAM 1^5S6 ^^^^'2 6 1966 ^^t"^- J4N 21 1965 uou LibitAi ^^^ JUiy 3 1970 1 P'^ LIBRARY, UNIVERSITY OF CALIFORNIA, DAVIS Book Slip-50m-12,'64(F772s4)458 381805 TC82U Calif . Dept . of Water C2 Resources. A? Bulletin. no.l3lj:62 PHYSICAL C.2 SCIENCES LIBRARY UNIVERSITY OF CAUFfpt^NIA .OWjS 3 il75 02468 6597 PI s<