^a^^aa^ EX L1BRIS STATE OF COLORADO COOPERATIVE OIL SHALE INVESTIGATION 2S2? (In Cooperation With the United States Bureau of Mines) MARTIN J. GAVIN, Engineer in Charge "^ERSITYOFCAI BULLETIN NO. 1 Ider, July 1,1921 Short Papers from the Co- operative Oil-Shale Laboratory By MARTIN J. GAVIN and LESLIE H. SHARP Denver, Colorado EAMES BROTHERS, STATE PRINTERS 1921 STATE OF COLORADO COOPERATIVE OIL SHALE INVESTIGATION (In Cooperation With the United States Bureau of Mines) MARTIN J. GAVIN, Engineer in Charge BULLETIN NO. I Boulder, July 1,1921 Short Papers from the Co operative Oil-Shale Laboratory By MARTIN J. GAVIN nd LESLIE H. SHARP Denver, Colorado EAMES BROTHERS, STATE PRINTERS 1921 Plate Plate II. Plate III. LIST OF ILLUSTRATIONS Page I. The Co-operative oil-shale laboratory at Boulder 5 Typical oil-shale ledge in Colorado Typical oil-shale formation in Colorado 8 Plate IV. Horizontal retort at Boulder laboratory 12 Plate V. Map of Northwestern Colorado 26 FIGURES Page Fig. 1. Graphic representation of retorting test No. 1 30 2. Graphic representation of petortirigttest No. 2 31 3. Graphic representation of retorting test No. 3 32 4. Graphic representation cl telortijfi-g' tet No. 4 33 5. Graphic representation of retorting test No. 5 34 6. Graphic representation of retorting test No. 6 35 1. Graphic representation of retorting test No. 1 , 36 8. Graphic representation of retorting test No. 8 37 9. Graphic representation of retorting test No. 9... ...38* CONTENTS Page Letter of transmittal 6 Preface A 7 Introduction 9 Acknowledgments . 11 Fuel values of oil-shale and oil-shale products 13 Summary .20 Observations on shale gas . 22 Conclusions '. 24 Results of nine oil-shale retorting tests - 27 Introduction 27 Experimental plan 27 Description of experimental work .28 Discussion of retorting tests 39 Conclusions 40 Future retorting work 41 Analytical distillation of shale oil from Colorado oil-shale 42 Introduction 42 Laboratory procedure for examining shale oils 43 Interpretation of results of distillation analyses ..45 Comparison of analyses of shale oils 51 Thermal calculations on the retorting of oil-shales 52 Introduction 52 Method of making calculation of heat required for retorting 52 Comparison of calculated and experimentally determined heat requirements 55 Calculation of heat available from shale gas and spent shale 56 Thermal efficiencies of retorts necessary to retort oil-shales of different richness 56 Convenient factors for use in oil-shale calculations.... ...61 KfcLOSOQ TABLES Page Table I. Summary heats of combustion or fuel values of oil- shale and its products 14 II. Factors necessary in calculating heat balances 17 III. Heat distribution in one gram of fresh shale and products obtained from it 17 IV. Percentage heat distribution ...18 V. Heating values of shale and shale products compared with other fuels.... 18 VI. Table showing relation between jgas production, oil production, temperature and heating value of gas produced 23 VII. Composition of shale and other gases 25 VIII. Summary of nine retorting tests on Colorado oil- shales 29 IX. (A-D) Analytical distillation of shale oil from Colorado oil-shale 48-49 IX. (E) Analytical distillation of shale oil from Scot- land 50 IX. (F) Analytical distillation of crude oil from Penn- sylvania 50 X. Composition by weight of one ton of shale 57 XI. Total heating value of ^oil-shales of varying richness. .57 XII. Heat value of products of oil-shales of different rich- ness 57 XIII. Heat recoverable in products of oil-shales of varying richness 58 XIV. Heat required to retort oil-shales of varying rich- ness 59 XV. Necessary thermal efficiencies of retorts 60 XVI. Frequently used equivalents 61 XVII. Some constants for shale and shale products 62 XVIII. Heat equivalents 62 XIX. Temperatures 62 XX. Weight of shale 63 XXI. Petroleum oil table for converting specific gravity to Baum6 degrees 63 XXII. Petroleum oil table for converting Baum6 degrees to specific gravity 64 XXIII. Temperature corrections to readings of specific gravity hydrometers in American petroleum oils at various temperatures 65 XXIV. Temperature corrections to readings of Baum6 hydrometers in American petroleum oils at vari- ous temperatures ., 66 XXV. Relation between altitude and barometric pressure.. 6 7 XXVI. Factors for use in calculating results of oil-shale assays 67 XXVII. Other factors frequently used in making oil-shale assay calculations ...68 LETTER OF TRANSM1TTAL DEPARTMENT OF THE INTERIOR BUREAU OF MINES WASHINGTON TO HIS EXCELLENCY, The Honorable Oliver H. Shoup, Governor of Colorado. Sir: I have the honor to transmit six short papers by M. J. Gavin, Oil Shale Technologist, U. S. Bureau of Mines, and L. H. Sharp, Chemical Engineer for the State of Colorado. These papers pre- sent the results of certain studies made at the Co-operative Oil Shale Laboratory, Boulder, Colorado. Further reports of the studies, which are still in progress, will be transmitted when com- pleted. Cordially yours, H. FOSTER BAIN, Director, U. S. Bureau of Mines. PREFACE. This paper is a presentation of the results of preliminary studies at the-Colorado Co-operative Oil Shale Laboratory, Boulder, Colorado, which were begun February 1, 1920, by the U. S. Bureau of Mines and the State of Colorado, under a co-operative agreement entered into by the Bureau and the State, utilizing funds which were provided by the State, and the services of engineers provided by the Bureau. The investigations are for the purpose of determining by large- scale laboratory retorting tests, those conditions which will pro- duce optimum yield of best quality of products from Colorado shales. It seems fairly certain that the peak of the petroleum produc- tion curve in the United States will be reached in a few years, but the curve of consumption will contine in its upward rise. To meet this situation, either imports must be increased in the future, or means must be found to utilize the immense oil-shale deposits of Colorado and other western states as a source of the needed oil. This last is not a simple problem. While oil shales have been worked in Scotland and France for many years, it was in competi- tion with high-priced petroleum products and with low labor costs, with the added advantage that the industry is there situated in a densely populated region where a ready market for oil and ammo- nimum' products was available. Even these long-established indus- tries are passing through a difficult period at present. The oil shales of the Rocky Mountain region occur in sparsely settled com- munities and their development will mean bringing into the region great numbers of working men, with their families, for whom hous- ing and the conveniences of living must be provided, in addition to the millions of dollars which must be spent in constructing plants, equipping mines, and providing transportation facilities. About one million barrels of oil are now produced each day in the United States and to produce one barrel of oil from oil-shale will involve the mining and crushing of at least one ton of tough material, heat- ing it to a high temperature and finally disposing of three-fourths of a ton of waste residue. It naturally follows that an enterprise which bids fair to be so important to the State of Colorado justifies the most careful investigation to assure that development shall be along the right lines, since the loss of capital resulting from too-hasty construction of unsuitable plants would be certain to prove an obstacle to secur- ing the needed capital for the development of the industry. Until the fundamental factors underlying the development of the oil shales of the Rocky Mountain region have been clearly and accu- rately ascertained, no sound development of the oil shale industry will be possible. A. W. AMBROSE, Chief Petroleum Technologist, Washington, D. C., U. S. Bureau of Mines. May 15, 1921. 8 l SHORT PAPERS FROM THE Plate II. Typical Oil-Shale Ledge in Colorado Plate III. Typical Oil-Shale Formation in Colorado CO-OPERATIVE OIL-SHALE LABORATORY INTRODUCTION. In January, 1920, the State of Colorado and the United States Bureau of Mines entered into a co-operative agreement for the con- duct of laboratory investigations on the oil-shales of Colorado. Under this agreement a laboratory has been installed and equipped at the State University, Boulder, Colorado, and a research staff organized. It is the primary purpose of the investigation! work to determine the most favorable conditions of retorting Colorado oil- shales to yield the most of the best products from them. Work of this nature involves retorting the oil-shale under many conditions and the examination of products obtained in each test to determine the effect of the conditions imposed during the test. New problems continually arise which call for the development of new methods for their solution and frequently interesting develop- ments are investigated only to give results of negative value. It becomes apparent that a great deal of time will be required before the main purpose of the investigation can be accomplished. How- ever, in the course of the main investigation it was necessary to take up certain side investigations which were directly connected with the main plan of the work. Many of these minor investigations have yielded results of sufficient interest and importance that it has been considered worth while to bring them to the attention of the public before the principal results of the main investigation can be published. Two papers 1 dealing with the program of the investigations and with some of the work already accomplished have already been published in mimeographed form by the Bureau of Mines, and it is the purpose of the Bureau and State to continue publishing short reports as frequently as material becomes available. The final results of the completed investigations are to be the subject of a Bureau of Mines bulletin. This present paper deals with several subjects which will be of interest to those engaged in the development of an industry from the immense deposits of oil-shales in Colorado and adjacent states. It is a compilation of six short reports which have been prepared in the course of the investigational work. The fuel values of oil-shale and oil-shale products are discussed in the first paper; the nature and composition of shale ga,s is presented in the second ; the third gives production tables and curves for shale oil as obtained from the horizontal rotary retort used in the Boulder laboratory; the analytical distillation of shale oils is taken up in the fourth report ; the fifth gives data on thermal calculations for the retorting of oil- shales, and the sixth is a tabulation of factors and formulae which have been found of value in the Boulder co-operative laboratory and the oil-shale laboratory at the Intermountain Experiment Station of the Bureau of Mines, Salt Lake City, Utah. 1 Gavin, M. J., and Sharp, L. H., Investigation of the fundamentals of oil-shale retorting-, Bureau of Mines. Reports of Investigations, Serial No 2141, July, 1920, 4 pp. Reprinted in Eng. World, Sept., 1920. Gavin, M. J., and Sharp, L. H., Some physical and chemical data on Colorado oil-shale, Bureau of Mines, Reports of Investigations, Serial No. 2152, August, 1920, 8 pp. Reprinted in Eng. and Min. Jour., Sept. 18 1920- Oil Paint and Drug Reporter. Sept. 13, 1920; and Gas Age, Sept. 25, 1920 10 SHORT PAPERS FROM THE Attention is called to the fact that the data given, except those in the last paper, can be expected to apply only to the oil-shale worked with and. the products recovered therefrom under the par- ticular conditions used in the investigations. However, the material being worked with is believed to be a fairly representative sample of Colorado oil-shale, and if due allowances are made for the vary- ing richness of different shales, the results may be expected to be applicable, with a reasonable degree of accuracy, to all shales of the Green River formation. CO-OPERATIVE OIL-SHALE LABORATORY 11 ACKNOWLEDGEMENTS. The writers gratefully acknowledge the services rendered by Mr. James Duce, State Oil Inspector of Colorado, in perfecting co-operative agreements and in arranging for laboratory and office space, and are especially grateful to him for the many valuable suggestions he has made and for the deep interest he has taken in the work. To Professors John A. Hunter and Jay W. Woodrow as well as other faculty members and the regents of the University of Colo- rado, thanks are due for the co-operative spirit shown by them and for the material assistance they have rendered in many ways. Ac- knowledgements are made to Alvah M. Hovlid, of the Co-operative Laboratory, Boulder, for assistance in carrying out much of the experimental work leading to the results herein presented, and to L. C. Karrick and J. J. Jakowsky, the authors' associates in the Bureau of Mines Experiment Station, Salt Lake City, Utah, for assistance in preparing manuscript and for valuable suggestions as to the conduct of the experimental work. Mr. Jakowsky also pre- pared curves Nos. 1 to 9. Manuscript was prepared by Miss Louise Helson of the Salt Lake City Station of 'the Bureau of Mines, and Mr. A. T. Strunk of the Boulder Laboratory. Mr. Arthur J. Franks of Golden, Colorado, kindly supplied certain results of his oil-shale studies for use in connection with the paper on Thermal Calculations on the Retorting of Oil Shales. The manuscript was constructively critised by T. E. Swigart and N. A. C. Smith of the Bureau of Mines. 12 SHORT PAPERS PROM THE Plate IV. Horizontal Retort at Boulder Laboratory. Scrubbers in Foreground CO-OPERATIVE OIL-SHALE LABORATORY 13 FUEL VALUES OF OIL-SHALES AND OIL-SHALE PRODUCTS. Subsequent to the publication 1 of the heats of combustion of a fresh oil-shale yielding 42.7 gallons of oil to the ton, and the spent shale and oil derived therefrom, it has seemed advisable to secure similar data for shales of varying oil yield and different physical and chemical characteristics, in order to furnish geologists and engineers with an accurate basis for calculating the thermal values of oil-shales and their products, especially for possible retort fuels. Accordingly, six samples of shale of diversified character as indicated below were selected, determinations of the heats of com- bustion of the fresh shales and of the spent shales and oils derived from them were made, and the heat value of the derived gases cal- culated. CHARACTERISTICS OF SHALES USED. Oil Yield Water Yield on Assay; on Assay Physical Chemical Gals. From Nature Gals. No. Composition Nature Per Ton Locality Oil Per Ton 1 Massive Limy 10.0 Dry Fork 1 Light 1.06 2 Massive Siliceous 28.0 Conn Creek l Med. waxy 4.22 3 Massive Siliceous 37.0 Conn Creek 1 Med. waxy 3.16 4 Massive Siliceous 42.7 Conn Creek 1 Med. waxy 3.16 5 Thin "paper" Mouldy organic 75.5 Dry Fork x Gassy light 6.04 6 Semi-massive Siliceous "paper" organic 76.2 Mt. Logan 1 Med. waxy 6.30 1 Near DeBeque, Colo. In all cases the samples were crushed to i/4 mesh in a chip- munk crusher, the crushed shale thoroughly mixed and sampled, then approximately one pint of each shale was taken for assay. The assays were made by the method recommended by the U. S. Bureau of Mines for oil-shale assay. 2 The residues were care- fully weighed and sampled and distillation losses noted. Oils were preserved in glass stoppered flasks. All samples of fresh and spent shale were ground to pass a 100 mesh screen and heats of combus- tion determined in the standard Emerson bomb calorimeter. The heat of combustion of oils was then determined in the same appara- tus. (300 to 350 pounds of oxygen pressure were used in all deter- minations and temperature readings were taken with a Beckman differential thermometer. ) Check determinations were run. The determinations were corrected for unburned material 3 as shown in the following table. A further check in the form of total ignition loss determination was made. 1 Gavin, M. J., and Sharp, L. H., Some physical and chemical data on Colorado oil-shale, Bureau of Mines, Reports of Investigations, Serial No. 2152. August, 1920. 8 pp. 2 Karrick, L. C., A convenient and reliable retort for assaying oil-shales for oil yield, Bureau of Mines, Reports of Investigations, Serial No. 2229, March, 1921. Reprinted in Eng. and Min. Jour., April 30, 1921. 3 Gavin, M. J., and Sharp, L. H., Some physical and chemical data on Colorado oil-shale, Bureau of Mines, Reports of Investigations Serial No. 2152, August, 1920. 8 pp. 14 SHORT PAPERS FROM THE EH O i o 7 J ^H Q z ^ o HH o EH P P5 o o 5 p a s o CQ H w 3 P3 <^ a 00 SI x 0) bc^ Sbc rH OS rH ffi t- e. err. 0.853.. 10905 Gaseous: per cu. ft. Shale gas, early stages 1 A 482.0 Shale gas, oil 15 to 90 per cent off 1 B 976.0 Shale gas, oil 90 to 100 per cent off 1 C 526.0 Shale gas, oil all off 1 D 213.0 No. cu. ft. shale gas to equal 1 cu. ft. other gas Natural gas 2 . ..1000 A 2.08 B 1.03 C 1 90 D 4 70 Oil gas 2 634 1 32 65 1 21 2 98 Coal gas 2 683 1.42 0.70 1.30 3.20 153 32 16 29 72 "Blue" water gas 2 322 0.67 33 61 1 51 Obtained by dry destructive distillation in batch retort; efficiency of gas scrubbing doubtful. 2 Average values. In the discussion under paragraphs E, F, and G, certain fac- tors were presented by means of which, if the heat value of a sam- ple of shale is known, the heating value of its products gas, oil, CO-OPERATIVE OIL-SHALE LABORATORY 19 and spent shale can be calculated. These factors represent the percentage of the total heating value of the raw shale appearing in each of the products, and as can be noted in Table IV, the per- centage of the original heating value of the shale found in the gas is determined by difference from 100 per cent, as the heating values of the shale, oil, and spent shale have been experimentally deter- mined. On first impression, it would appear that the sum of the heat values of the products of oil-shale should equal the heat value of the raw shale, but this does not necessarily follow. As a matter of fact the percentage distribution of heating values, as shown in Table IV, applies very well for shales yielding up to 50 gallons of oil per ton, but for richer shales experiments in which the actual heating values of shale gas were determined, have indicated that the percentages representing heating value distribu- tion must be somewhat modified to obtain fuel values for the spent shale and shale gas that are consistent with actually observed values. * It has been determined by experience that the following distribu- tion of the heating value of the raw shale among its products agrees closely with observed values for shales of different richness : (If the total heat value of the raw shale is found from the formula: 106.6 X oil yield in gallons per ton = B.T.U. per pound of shale.) (See page 16.) Up to 50 gals. 50 to 80 gals. 80 to 100 gals. For shales yielding on per con oil per ton oil per ton Percentage of total heating value of raw shale found In oil 65.00 65.00 65.00 In spent shale 18.65 15.00 11.00 In gas 15.35 16.00 16.00 Percentage unaccounted for 1.00 4.00 8.00 The figures shown in the first column are rounded averages for those shales discussed in this paper which yielded up to 50 gallons of oil per ton, and it is believed that they may be applied without serious error. The values given in the other columns have been somewhat arbitrarily chosen from results on rich shales not reported in this paper. As most shales which will be com- mercially worked do not usually yield over 50 gallons of oil to the ton, it was not thought worth while to spend any great amount of time in determining factors for richer shales. It is interesting to consider what becomes of that part of the heating value of the raw shale designated as "unaccounted for" when the shales are distilled. It is entirely possible that there have been high distillation losses in the distillation of the richer shales, which may not have been observed, but the writers do not believe this to be the case. The decomposition of oil-shale into its products is a thermo-chemical process, and it seems most likely that the heat unaccounted for represents, in a measure at least, the heat of reaction of the distillation process. The heat of reaction of the process undoubtedly differs with different shales, and with the same shales when they are distilled under different thermal conditions, thereby producing different end products. 20 SHORT PAPERS FROM THE SUMMARY. The results of the work presented in this paper make it pos- sible to draw the following- conclusions: 1. There is no mathematical relationship between the spe- cific gravity of an oil-shale and the amount of oil yielded by it. The idea that shales of low specific gravity yield much oil, if used at all, must be applied with caution. 2. The ignition loss of an oil-shale cannot properly be used in estimating the amount of oil the shale will yield. 3. The heat of combustion of an oil-shale is a fairly accurate indicator of the amount of oil the shale will yield, and, conversely, the oil yield is a reliable indicator of the heat value of the shale as a fuel. 4. The heat value per gram of spent shales apparently tends to approximate a constant percentage of the heat value per gram of the shales from which they were formed, rather than a con- stant average heat value, when the shales are retorted under constant conditions. For the conditions of retorting used in these experiments, this percentage is 23.19. 5. In the experiments reported in this paper, the amount of heat recoverable in the shale oil tends to approximate a definite percentage of the heat of combustion of the original shale. For the conditions of retorting used in these experiments this per- centage is 68.28. If, as is here indicated, only 68.28 per cent of the original fuel value of the shale is contained in the oil recovered by dry destructive distillation, it seems highly desirable, from a view- point of national economy, that both the spent shale and shale gas be used as fuel to the fullest extent. When the fuel values of these latter products are considered, however, it is doubtful if such use will always be the most profitable from a financial standpoint. 6. For fairly approximate work it can be taken that the oil yield of a shale (as determined by assay) in gallons per ton, mul- tiplied by the factor 106.6 equals the gross heat of combustion of the shale in B.T.U. per pound: 7. To obtain the net heat value the factor 106.6 may be cor- rected as follows: (a) For every gallon of water per ton which is vaporized, subtract 4.66 from the 106.6 factor. (~b) For every degree Fahrenheit above 212 F. (boiling point water) each gallon of vaporized water (steam) is raised in temperature before its discharge, a further subtraction of 0.002 should be made from the 106.6 factor. Example: A shale assaying 50 gallons oil and 2 gal- lons water per ton, is used as fuel where flue gas exit temperature is 612 F. CO-OPERATIVE OIL-SHALE LABORATORY 21 Gross heating value is 50 X 106.6 = 5330 B.T.U. per pound. Net heating value is 50 X [106.6 -- (2 X 4.66) - - (400 X 0.002)] = 50 X 96.48 = 4820 B.T.U. per pound. 8. For shales yielding up to 50 gallons of oil per ton the following relations can be used for close approximations : (a) Heat value of raw shale multiplied by 0.1742 equals the total heat value in B.T.U. of the spent shale derived from it. (~b) Heat value of raw shale multiplied by 0.6706 equals the total heat value in B.T.U. of the oil derived from it. (c) Heat value of raw shale multiplied by 0.1552 equals the total heat value in B.T.U. of the gas produced from it. These relationships hold only for dry destructive distillations under the conditions used in these tests. For shales richer than those yielding 50 gallons of oil to the ton, the above factors must be modified as indicated on page 19. 22 SHORT PAPERS FROM THE OBSERVATIONS ON SHALE GAS. Frequent mention has been made of the possibility of supply- ing all or part of the heat necessary to retort oil-shale by burning the uncondensible gas under the retort as fuel. This paper has been prepared to present the findings with regard to the feasi- bility of this plan. In a paper on the "Fuel Values of Oil-Shales and Oil-Shale Products" (see Table IV) the writers show that from 9.0 to 18.1 per cent of the heat value of the shale is represented, after retorting by dry destructive distillation, by the uncondensible gases. The average for the shales examined was about 15.0 per cent. From this it is evident that the total heat value obtainable from uncondensible gases varies much with different shales. It will also differ with different conditions of retorting. The tests described below show that the heating value of the gas also varies more or less according to time at which the gas is formed with reference to oil production. This statement ap- plies also to the chemical composition of the gas. 1 In Table VI the results tabulated under Shale No. 10 are the average of those obtained in four retort tests on 75-pound samples of shale assaying 42.7 gallons of oil per ton; those under Shale No. 11 are an average of observations made on four retort tests using 75 pounds of shale yielding, on assay, 37 gallons of oil per ton; and those under Shale No. 12 are the observations made on a single retort test using 75 pounds of shale yielding, on assay, 28 gallons of oil per ton. 1 During tests on shale samples Nos. 11 and 12, Table VI, all gas was scrubbed, an average of 0.115 gallons of gasoline being absorbed from 1000.0 cubic feet, as follows: Test No. 5. 36.75 cc. from 132.8 cu. ft. or 0.0728 gals, per 1000 cu. ft. Test No. 6. 23.00 cc. from 36.3 cu. ft. or 0.167 gals, per 1000 cu. ft. Test No. 7. 46.00 cc. from 81.5 cu. ft. or 0.149 gals, per 1000 cu. ft. Test No. 8. 26.00 cc. from 93.5 cu. ft. or 0.0733 gals, per 1000 cu. ft. There is a possibility that the scrubbing was somewhat incomplete on account of a too rapid gas flow. The gas samples referred to were produced in the course of shale retort- ing tests made in the United States Bureau of Mines and State of Colorado co-operative oil-shale retort at Boulder, Colorado. Briefly, this retort is an externally gas fired, horizontal, rotary, iron cylinder with a pyrometer well in one end and the vapor exit in the other. The vapors are drawn through an air-cooled and a water-copied condenser, then pumped through water and a light "straw" oil. On leaving the oil scrubber the gases are metered. The heating value of the gas is next determined with a Junkers calorimeter set. Samples are collected over water for analysis by a standard portable Williams Orsat pipette. CO-OPERATIVE OIL-SHALE LABORATORY 23 & p SH H O D ,0 OCn | 00 o W CQ <^ H f*>:l 53 ft .S o ^ o eg co 03 so ooc<5 -^eo coco O O3 W rH in eg ; ft 0)0 ft ; ft o o SI|isl|IIiIilgSisll _ rH UJ 'Q l O IO O U3 'o IO 'o O 'o O O O *O O 'S " rHrHrHrHi-HOSOSOSOi c 0, S t S -H c c c o ' - 00^; "- " 05 <|) >, SSs * ^"2220 ; i H2o)^S o3 c g-8WR5 ..2^.0 24 SHORT PAPERS FROM THE CONCLUSIONS. The following conclusions may be reached as a result of the experimental evidence presented in Table VI and later work, results of which were unavailable for presentation in detail in this bulletin. 1. In general the thermal value of the gas rises with the temperature at which the gas was formed, until some 90 per cent of the oil obtainable has been distilled from the shale. 2. Before 15 per cent of the obtainable oil is distilled from the shale, the heat value of the gas is approximately 482 B.T.U. per cubic foot. 3. After 15 per cent of the possible oil has been recovered, and until 90 per cent is obtained, the thermal value of the gas rises to an average of 976 B.T.U. per cubic foot. 4. After 90 per cent of the obtainable oil has been recovered, the average thermal value of the gas is about 526 B.T.U. per cubic foot, or very similar to that obtained during the time of producing the first 15 per cent of the oil. 5. After all the oil has been yielded by the shale, the thermal value of the gases formed drops to a value of about 213 B.T.U. per cubic foot, and probably remains between 200 and 300 B.T.U. until gases cease to be evolved. 6. In the early stages of retorting there seems to be no definite relation between the thermal value of the gas and the rate of oil production. This seems to hold true until after 90 per cent of the oil yield is obtained, after which time the heating value of the gas seems to fall off, roughly as the rate of oil pro- duction decreases. 7. There is apparently no connection between the rate of gas production and its heating value, or between the rate of tem- perature rise just before the calorific determination, and the value of the latter. It was intended that a gas sample, for analysis, should be collected during or immediately after each calorific value test. The samples were collected but due to breakage of apparatus it was necessary to delay some of the analyses until their results were manifestly incorrect, and therefore only three are sub- mitted. These three are results obtained on freshly collected samples and are therefore believed to actually represent the gases as they were produced. The exact conditions of the tests, so far as the apparatus permitted their observation at the time of sampling the gases, together with the analyses of the gases, are shown in Table VII. Average analyses of various other natural and artificial gases are also included in the table for comparison. The authors appreciate that it is unjustifiable to draw con- clusions from the results of so few analyses. The analyses are appended, however, to show the nature of the work under way and to give, at least, a preliminary idea of the nature of the shale gas obtained under the conditions prevailing in the experimental work. CO-OPERATIVE OIL-SHALE LABORATORY 25 H O P Hi > ^ I I V4i S o (puoj\[) 'S-BS OOSIOU13JJI UT3g 'STJS no 'S133 J8}UA1 S13S Ja^-BAV 1S8T osoooocoOO co co o N *" o co OOOMCOOM t- T*I 05 o < ooooooo in oo o om o TI< os co' o e - si i So PP 8S5| ^'H o_o" ww (Srntftfa! CO . i >, C 'p .^ o _4j O a tSOO 2000 3500 CC. ~ O/L AMD Figure 1. Graphic Representation of Retorting Test No. 1. Date: May 20, 1920. Colorado Oil Shale. Assay, 42.7 gallons oil per ton. Average heating rate, 3.88 F. per minute. Pressure, atmospheric. Oil curve not corrected for water in suspension; see Table VIII and page 41. Total water in suspension this run, 431 cc., or 8.26 per cent. CO-OPERATIVE OIL-SHALE LABORATORY 31 *X> 300 300 400 ^500 6OO TOO 3OO SOO fOQO /tOO 4OOO Piffure 2. Representation of Retorting Test No. 2. Date: May 25, 1920. Colorado Oil Shale. Assay, 42.7 gallons oil per ton. Average heating rate, 6.12 F. per minute. Pressure, atmospheric. A Oil is oil condensed in air cooled condenser. B Oil is oil condensed in water cooled condenser. Oil curves not corrected for water in suspension. See Table VIII and page 41. Total water in suspension this run, 486 cc., or 8.26 per cent. 32 SHORT PAPERS FROM THE /OO 200 300 4OO &JO 600 TOO QOO 9OO fOOO 4000 Figrire 3. Graphic Representation of Retorting- Test No. 3. Date: May 29, 1920. Colorado Oil Shale. Assay, 42.7 gallons oil per ton. Average heat- ing rate, 6.82 F. per minute. Pressure, reduced, as indicated. A Oil is oil condensed in air cooled condenser. B Oil is oil condensed in water cooled condenser. Oil curves not corrected for water in suspension. S^e Table VIII and page 41. Total water in suspension this run, 371 cc., or 8.26 per cent. (1) Calorific value of gas, 482 B. t. u.; (2) Calorific value of gas 492 B t u (3) Meter broke. CO-OPERATIVE OIL-SHALE LABORATORY /OO BOO 300 400 &OO 6OO TOO BOO 9OO fOOO -500 tOOO *SDO 000 C.C ~~O/L 3OOO WATER 3500 4000 Pig-ure 4. Graphic Representation of Retorting- Test No. 4. Date: Au- gust 20, 1920. Colorado Oil Shale. Assay, 42.7 gallons oil per ton. Average heating rate, 8.16 F. per minute. Pressure, reduced as indicated. A Oil is oil condensed in air cooled condenser. B Oil is oil condensed in water cooled condenser. Oil curves not corrected for water in suspension. See Table VIII and page 41. Total water in suspension this run, 266 cc., or 6.93 per cent. (1) Calorific value of gas, 1045 B. t. u. 34 SHORT PAPERS PROM THE /OO JBOO 3OO 4OO &OO GOO TOO 600 9OO /OOO Pigure 5. Graphic Representation of Retorting Test No. 5. Date: Sep- tember 30, 1920. Colorado Oil Shale. Assay, 37.0 gallons oil per ton \verage heating rate, 3.56 F. per minute. Pressure, atmospheric. A Oil is oil con- densed in air cooled condenser. B Oil is oil condensed in water cooled con- denser. Oil curves not corrected for water and suspension. See Table VIII and page 41. Total water in suspension this run, 573 cc., or 13 9 per cent (1) Calorific value of gas, 274 B. t. u. (2) Gas sample taken. (3) Gas sample taken. (4) Gas sample taken. (5) Calorific value of gas, 141 B t u (6) Gas sample taken. CO-OPERATIVE OIL-SHALE LABORATORY 35 /OO 300 300 400 <500 6OO TOO GOO 9OO /OOO //OC 300 WOO tSDO 000 C.C. - O/Z. &SOO 3OOO 3GOO 4OOO Figure 6. Graphic Representation of Retorting Test No. 6. Date: Octo- ber 9, 1920. Colorado Oil Shale. Assay, 37.0 gallons oil per ton. Average heating rate, 3.49 F. per minute. Pressure atmospheric. A Oil is oil con- densed in air cooled condenser. B Oil is oil condensed in water cooled con- denser. Oil curves not corrected for water in suspension. See Table VIII, and page 41. Total water in suspension this run, 413 cc., or 9.18 per cent. (1) Heating value of gas, 1,049 B. t. u. Gas sample taken. (2) Heating value of gas, 843 B. t. u. Gas sample taken. (3) Heating value of gas, 285 B. t. u. Gas sample taken. 36 SHORT PAPERS FROM THE 00 300 400 ^00 GOO TOO BOO 9OO /OOO //OO sooo asoo 3000 3500 ?ooo PigTire 7. Graphic Representation of Retorting Test No. 7. Date: Octo- ber 13, 1920. Colorado Oil Shale. Assay: 37.0 gallons oil per ton. Average heating rate, 3.46 F. per minute. Pressure, atmospheric. A Oil is oil con- densed in air cooled condenser. B Oil is oil condensed in water cooled con- denser. Oil curves not corrected for water in suspension. See Table VIII and page 41. Total water in suspension this run, 418 cc., or 9.31 per cent. (1) Heating value of gas, 708 B. t. u. (2) Heating value of gas, 817 B. t. u. CO-OPERATIVE OIL-SHALE LABORATORY 37 KX> SCO <5OO 400 OO GOO TOO 6OO SOO fOOO ^fOO 4000 c.c-o/t Pig-lire 8. Graphic Representation of Retorting Test No. 8. Date: Octo- ber 15, 1920. Colorado Oil Shale. Assay, 37.0 gallons oil per ton. Average heating rate, 3.36 F. per minute. Pressure, atmospheric. A Oil is oil con- densed in air cooled condenser. B Oil is oil condensed in water cooled con- denser. Oil curves not corrected for water in suspension. Se^ Table VIII, and page 41. Total water in suspension this run, 318 cc., or 7.56 per cent. (1) Heating value of gas, 994 B. t. u. (2) Heating value of gas, 1,126 B. t. u. (3) Heating value of gas, 741 B. t. u. , 38 SHORT PAPERS FROM THE TEMPERATURE < Y^ JQO BOO 300 *X> *5DO GOO TOO GOO 9OO XXX? //(%> 300 /OOO 3OOO 3SOO 3000 35OO 4OOO M44TE&. Fig-ore 9. Graphic Representation of Retorting Test No. 9. Date: Octo- ber 27, 1920. Colorado Oil Shale. Assay, 28.0 gallons oil per ton. Average heating rate, 6.38 F. per minute. Pressure, atmospheric. A Oil is oil con- densed in air cooled condenser. B Oil is oil condensed in water cooled con- denser. Oil curves not corrected for water in suspension. See Table VIII, and page 41. Total water in suspension this run, 313 cc., or 11.25 per cent. (1) Heating value of gas, 312 B. t. u. CO-OPERATIVE OIL-SHALE LABORATORY 39 DISCUSSION OF RETORTING TESTS. As has been mentioned, the first four tests were not run accord- ing to any definite program, and so many variables entered into these tests that it is impossible to draw conclusions as to the effect of any one variable. In tests Nos. 5 to 8 all conditions were held as nearly constant as possible. The first four tests were made with the retort rotating at seven revolutions per minute. This rate was found to be too rapid, as it produced a decided ball-mill effect on the shale. Consequently the rate of rotation has been reduced to 3.75 revolutions per minute, which seems to be quite satisfactory, and was adhered to in the other tests reported. This rate will be used in the future. The first two tests were made under atmospheric pressure, and it was noticed that a certain amount of dust was carried over into the. condensing system and pump. In tests Nos. 3 and 4, made under vacuum, carrying over of the dust became so serious that a drum-head, made of iron screen and packed with steel wool, was placed in the discharge end of the retort, just in front of the vapor outlet. This seems to prevent trouble due to dust, but as the screen- head apparently has a bad effect on the oil, evidently producing cracking, it may be necessary to remove it. With the slow rate of rotation now being used it is believed that the use of the screen- head will be unnecessary, unless the retort is operated under re- duced pressure. Tests Nos. 3 and 4 were made under vacuum, as may be noted in Table VIII. Rather unexpected results were obtained. It was believed that a higher recovery of oil and a smaller amount of gas would be obtained from the shale under reduced pressure. Entirely contrary results were obtained. Since only two vacuum tests were made it is difficult to account for this fact, and no attempt is made to explain it, except that excessive cracking or incomplete conden- sation may have been responsible for the unexpected results. At the proper time in the course of the experiments the effects of reduced pressures will be carefully studied, making it possible to draw conclusions. The vacuum tests made indicate that the retort can be operated successfully under greatly reduced pressure with- out leakage. Tests Nos. 3 and 4 indicate also that the shale begins to produce oil at a lower temperature under reduced pressure than under atmospheric pressure. It will be noted in Table VIII that the rate of heating is given as real average rate of heating and also in terms representing apparent average rate of heating. The first takes no account of the time when temperatures remained constant or fell, but considers only that period during which the temperature was. actually rising and the total gross increase of temperature during that time. The second is obtained by dividing the total net temperature rise by the number of minutes required during the test to reach the maxi- mum temperature. It will be noted that the figures representing these two calculated rates are very nearly the same in the later tests, but the earlier ones show considerable variation, due to inex- perience with the apparatus. 40 SHORT PAPERS FROM THE CONCLUSIONS. Examination of Table VIII and the curves indicates the fol- lowing : A. Initial temperatures 1 . The evolution of gas in noticeable quantity commences between 200 and 250 F., and usually close to 235 F. (113 C.). Water probably starts distilling at about the same temperature as the gas and appears as condensed water from the condenser when the retort temperature is about 325 F. (163 C.). Oil begins to flow from the condenser when the temperature in the center of the retort reaches about 450 F. (232 C.). It is noteworthy that the shale used in tests Nos. 1 to 4 began to produce oil at a lower temperature than the other shales used. Vacuum reduced the initial oil production temperature considerably (see tests Nos. 3 and 4). B. Range of production. Gas production will continue considerably above the highest temperature used in these tests. The volume will probably increase for some time, and its heating value decrease. (See paper on shale gas, page 24.) Water is produced throughout the oil production range, but above 500 F. (260 C.) the water is usually emulsified with the oil, and cannot be separated by gravity! settling at ordinary tem- peratures. The average range for oil production is about 625 F. (350 C.), all of it being distilled off at a temperature between 1100 and 1150 F. (593-621 C.). Nearly all the oil (about 96 per cent) is produced before the temperature reaches 900 F. (482 C.). C. Yields. The total gas yield in the different tests varies from about 1,000 cubic feet per ton of shale to nearly 3,600 cubic feet, and aver- aged 1,770 cubic feet per ton. In no case was gas production forced to the limit. The oil yields show a considerable variation ranging from 59 to 89 per cent, based on assays. No gas scrubbers were used in tests Nos. 1 to 4. Water yields vary considerably, as different parts of the shale samples contain different percentages of water. In some of the tests reported water yields are higher than actual yields from the shale, as it is often necessary to clean the apparatus with steam at the end of the run to remove all the oil. This sometimes introduces an unmeasured amount of water into the results, especially if the steam and condensed oil emulsify. 1 See footnotes, Table VIII, on temperature measurement. Particular emphasis is directed to the position of the pyrometer. CO-OPERATIVE OIL-SHALE LABORATORY 41 Much water is produced in emulsion with the oil. Oil yields shown in Table VIII are corrected for water in emulsion, but yield curves in Figures 1 to 9 are not so corrected, as it was not possible to determine the percentage of water in emulsion in the oil as the oil accumulated in the measuring receiver. Percentage of emulsi- fied and suspended water is, however, indicated on the curves. D. Rate of temperature rise. Under this heading only tests Nos. 1 and 2, and 5 to 8 inclu- sive, can be discussed, for reasons above presented. It will be noted that the rates of heating used do not vary widely, but generally it appears that a greater yield of oil is obtained with the slower rates of heating. The effect on the quality of the oil has not been clearly established, but it appears that oils of better quality are produced at slower rates of heating. It has been noted in every case that when very rapid rates of heating were employed, the oil had the odor of badly cracked oil. The effect on gas production is apparently as is to be expected, that is, smaller quantities of gas are produced at the lower rates of heating. FUTURE RETORTING WORK. The retorting work now under way is to determine the effects of several variables on the products of retorting oil-shales. The effect of different rates of heating are being studied first, and tests are now being made with rates much more varied than reported in this paper. It has been suggested that a uniform rate of heating may not be a desirable function on which to base work of this sort, and that a uniform rate of oil production would be better. Theo- retically this suggestion has much merit but when its commercial applications are examined it would seem to limit certain types of retorts by greatly complicating their structure, if indeed it does not absolutely bar them. Work will be continued using different uniform rates of heating on the same shale, and then it is planned to make a series of tests, using constant oil production as a basis. After the most favorable heating rate has been determined for the particular shale under examination, other factors will be varied, as mentioned on page 27. It is particularly desired to determine the effects of different sizes of shale particles on the products made at different heating rates. Any suggestions and data bearing on this work from persons interested in oil-shale will be appreciated. 42 SHORT PAPERS FROM THE ANALYTICAL DISTILLATION OF SHALE OIL FROM COLORADO OIL-SHALE. INTRODUCTION. After each retorting test at the Boulder Co-operative Oil-Shale Laboratory, samples of the various products collected during the run are examined in the laboratory. An analysis is made of the gas evolved during retorting, and its calorific value is determined. Condensed water from the retort condensers is examined primarily to determine content of nitrogen. Liquids from the oil and water scrubbers are tested for content of gasoline and ammonia, respect- ively. Spent shale from the retort is assayed to determine com- pleteness of retorting, and a proximate analysis is made on it. Finally the oil recovered during the run is fractionally distilled, first at atmospheric pressure, and then under reduced pressure, and the fractions are examined. In some cases one overall sample of the oil produced during the run is taken. In others several samples are taken during the course of the distillation of the shale. Proper examination of the several samples indicates whether the oil produced from the shale changes during the retorting period. This paper presents a series of analyses of oils, all produced from the same shale during the same retorting test. The large horizontal rotary retort was charged with Colorado oil-shale, ob- tained near DeBeque, and retorting carried out. in the usual man- ner. The oil production was allowed to accumulate until the retort temperature, read as previously indicated, had reached 269 C. (516 F.), then the oil receiver was changed. Likewise receivers were changed when the temperature had reached 285 C. (545 F.), 322 C. (612 F.), and when the run was completed. Thus four oil samples were obtained, the first representing oil production from start of distillation to 269 C., >the second oil produced while the retort temperature increased from 269 to 285 C., and so on. This report deals with only one such test, but several others have been made, oil samples being taken at different temperatures and the retort being operated under different conditions. All these data are being compared and correlated. Analyses of oils made under different retorting conditions are valuable as they not only permit a comparison of products made under various conditions, but show the effect of any single condition on the quality of the product. In the near future a complete report will be issued giving details as to the analyses of the various oils produced during the first series of ten runs in the Boulder retort. This report will also attempt to indicate the specific effect of different retorting condi- tions on the quality of the oils produced. CO-OPERATIVE OIL-SHALE LABORATORY 43 LABORATORY PROCEDURE FOR EXAMINING SHALE OILS. The method used in examining shale oils is practically that used by the United States Bureau of Mines in examining petroleum, and consists essentially of the following steps i 1 1. The sample as received is heated in the container until it is fluid. (Most shale oils are of the consistency of butter at tem- peratures ranging from 60 to 95 F.) The container is then shaken to thoroughly, mix the contents and a small sample taken therefrom for determination of water percentage. 2. If the water determination indicates only a small percent- age of water, the sample is allowed to stand in a tightly stoppered container in a warm place until the bulk of the water has settled out, then a 600 cubic centimeter sample is carefully drawn off the top and placed in a copper topping-still. The light oil and water are distilled from the sample, and the water separated from the light oil. After the remaining oil in the topping-still has cooled, the light oil is added to it, and thoroughly mixed. If the topping is carefully done, and cold water used in the condenser, the loss during topping-distillation will not amount to more than a few tenths of one per cent. Many shale oils, however, contain a large percentage of water which will not separate on standing, and when such a sample is to be run, it is necessary to dehydrate the oil by means of a drying agent. In such cases the oil is placed in a strong steel container provided with a tightly fitting plug and thermometer-well, and five grams of calcium chloride are added for every cubic centimeter of water contained in the sample. The plug is then screwed down tightly and the container heated gradually until the contents have reached a temperature of 200 C. The container is now shaken until it has cooled to room temperature, when the contents may be removed. This method serves to dry thoroughly oils containing large amounts of water. 3. Specific gravity of the clean oil, dried by either of the above methods, is then taken at 15.56 C. (60 F.). Practically all shale oils are semi-solid at this temperature, and it is therefore necessary to use some type of specific gravity bottle adapted for use with solid oils and tars. The Barrett type of specific gravity bottle has been found satisfactory for this purpose. 4. The specific gravity of the oil having been determined, it is necessary to calculate the weight of oil corresponding to 300 cubic centimeters. This amount is weighed into the Bureau of Mines standard Hempel distilling flask. This flask, whose dimen- sions have been accurately fixed, consists of a spherical glass bulb of 500 cubic centimeter capacity, with a 10-inch vertical neck or column, and with a delivery tube springing from the neck nine 1 The apparatus and methods used in these tests with minor exceptions, have been developed in the Pittsburgh laboratory of the Bureau of Mines, and are fully described in Bulletin 209 of the Bureau of Mines, "The Analyti- cal Distillation of Petroleum" by E. W. Dean, soon to be issued. 44 SHORT PAPERS PROM THE inches up the column at an angle of 15 degrees from horizontal. After the oil has been poured into the flask (it is often necessary to heat the oil to a point of fluidity before it can be poured into the flask) an 8-inch column of iron "jack chain" to serve as a fractionating column is placed in the vertical neck. A cork, through which a thermometer passes, is fitted into the top of the vertical neck of the flask. The thermometer is so placed that the top of the mercury bulb is on a level with the bottom of the open- ing of the delivery tube. The delivery tube is connected to the condenser with a well-fitting cork. The condenser consists of a vertical three-bulb staggered glass tube, of standardized dimen- sions, set in an insulated jacket, which at the start of the distil- lation is filled with water and shaved ice. 5. In setting up the distilling outfit all joints are luted with a paste of litharge and glycerine. The Bureau of Mines usually employs an electric resistance heater, controlled by a variable resistance, to heat the flask. Distillation is allowed to proceed at the rate of about two cubic centimeters a minute, fractions being separated at every even 25 C. interval. The temperature of the first drop over is noted. The distillation is continued until the vapor temperature reaches 275 C., all fractions taken during the intervals of 25 degrees temperature rise being kept separate in stoppered glass tubes. 6. The flask is next allowed to cool, the column of chain is removed and two cones of copper gauze are inserted in its place. These cones are placed about one inch apart in the middle of the neck. The thermometer is then replaced, the flask connected to the condenser as before, and the delivery end of the condenser connected to a vacuum receiver. Fractions may now be obtained under vacuum without breaking the vacuum to change receivers. To prevent paraffin wax solidifying in the tube, the water in the condenser jacket is slowly heated with an electric immersion heater until it is nearly at the boiling point when distillation is complete. Vacuum distillation is conducted at a pressure of 40 millimeters of mercury, and at the same rate as during the air distillation. Cuts are made at a vapor temperature of 200 C., and at every 25 degrees up to 300 C., when the distillation is stopped. The residuum in the flask is allowed to cool, and its specific gravity and setting point are determined. 7. Fractions taken at atmospheric pressure are examined separately; volume and specific gravity of each fraction at 15.56 C. being determined. 8. Either the percentage of unsaturation of each fraction is determined, or the percentage of unsaturation of the combined fractions distilling up to 200 C. is determined. The separate or combined fractions distilling from 200 G. up to 275 C. are similarly tested. Percentage of unsaturation is the percentage soluble in sulphuric acid of 98 per cent strength. Briefly, the method of determining unsaturation consists of carefully mixing 5 cubic centimeters of the oil with 10 cubic centimeters of the CO-OPERATIVE OIL-SHALE LABORATORY 45 acid, in a small bottle with graduated neck, keeping the bottle well cooled while mixing the contents. The bottle is then placed in a centrifuge and centrifuged until a complete separation of the oil not acted on by the acid has been effected. 1 While it is realized that this method does not accurately determine the absolute percentage of unsaturated hydrocarbons in the shale oil fractions, nevertheless close checks and corre- sponding results can be obtained. The method is quite valuable for purposes of comparison because it indicates at least the com- parative order of refining loss that the oil will suffer. Under the conditions of the test, sulphuric acid probably does not re- move all the unsaturated hydrocarbons of the olefin series, and probably does remove some of the higher members of the sat- urated hydrocarbon series. The acid also removes nitrogen com- pounds from the oil. The acid, however, does remove all the hy- drocarbons that are most objectionable in refined products, al- though commercial refining losses can be expected to be consid- erably lower than the unsaturated percentages indicated in the tables. 9. The fractions taken under reduced pressure are also ex- amined separately. Volume and specific gravity at 15.56 C. are determined, using the specific gravity bottle for those fractions that are solid at that temperature. A Westphal specific gravity balance can be used for all fractions that are entirely fluid at the above temperature. 10. Setting -points of the vacuum fractions are determined by freezing a drop of the oil on the extreme end of the bulb of a cooled thermometer, inverting the thermometer and rotating it about a vertical axis while the temperature is allowed to rise at the rate of 1 C. per minute. In most cases the drop of oil will melt sharply at a definite temperature and flow down the thermometer bulb. This temperature is the setting point, and gives an indica- tion of the paraffin wax content of the fraction. In the case of some residuums, particularly if they contain much asphalt, the setting point cannot be determined accurately by this method. 11. The viscosities of the crude oil, and of the fractions taken off under vacuum, are taken at 60 C. (140 F.) by a Say- bolt Universal Viscosimeter, or a glass pipette viscosimeter giving results that can be converted into Saybolt readings. INTERPRETATION OP RESULTS OF DISTILLATION ANALYSES. The following is quoted from a paper by Dean 2 , indicating how the results of distillations are interpreted when petroleum oils are examined. iSee Dean, E. W., and Hill, H. H., The determination of unsaturated hydrocarbons in gasoline, Bureau of Mines Tech. Paper 181, 1917, for details of this method. 2 Dean, E. W., Properties of typicar crude oils from the eastern, producing fields of the United States, Bureau of Mines, Reports of Investigations, Serial No. 2202, January, 1921, 3 p. 46 SHORT PAPERS FROM THE "The methods employed by the Bureau of Mines for the dis- tillation analysis of crude petroleum have not been developed with the idea of obtaining figures that parallel the results of actual refinery practice. As refinery practice has never been standardized, it has been necessary to select a fundamentally re- producible basis of comparison, rather than attempt to work in terms of yields and properties of commercial products. ' ' The chief value of the present report lies in the fact that it permits a reasonably adequate comparison of different crude oils on the basis of fundamental, physical and chemical proper- ties. "It is believed while the most satisfactory use of the figures involves a comparison, there is also a need for some sort of 'rough and ready' interpretation in terms of commercial products. There- fore, the author has employed the following classification w r hich, even if it has no other justification, is convenient because it per- mits discussion in terms of 'given names.' 1. "The sum of all fractions distilling at atmospheric pres- sure below 200 C. (392F.) is reported as gasoline and naphtha. 2. "The sum of all fractions distilling at atmospheric pres- sure between 200 C. (392 F.) and 275 C. (527 F.) is reported as kerosene. 3. "The sum of all vacuum distillation fractions having Say- bolt viscosities (at 100 F.) of less than 50 seconds is reported as gas oil. 4. "The sum of all vacuum distillation fractions having Say- bolt viscosities (at 100 F.) between the inclusive limits of 50 and 99 seconds is reported as light lubricating distillates. 5. "The sum of all vacuum distillation fractions having Say- bolt viscosities (at 100 F.) between 100 and 199 seconds inclusive is reported as medium lubricating distillate. 6. ' ' The sum of all vacuum distillation fractions having Say- bolt viscosities (at 100 F.) of 200 seconds or more, is reported as viscous lubricating distillate." In the case of shale oils, the above interpretation must be applied with considerable care. In the first place, the unsatura- tion percentages of .the crude naphtha and kerosene fractions are usually very high, indicating a high refining loss, and therefore the percentages of finished gasolines and kerosenes will be con- siderably less than those indicated by the tables. How much the refining loss will be is as yet unknown. In the case of shale oil fractions taken off under vacuum, the term gas oil can probably be applied as above, but since little is known as yet of the properties of lubricating oils made from shale oil, a distillation analysis will not be of much value at the present time. Later on, of course, when shale oils are actually refined and used, results of the examination of lubricating frac- tions of shale oils produced by laboratory methods can be com- pared with the oils in use, and a reference point established. At CO-OPERATIVE OIL-SHALE LABORATORY 47 present all fractions distilling under vacuum above 225 C. are classified as crude lubricating distillates, no attempt being made to classify further. About the only conclusion which can be reached at present is that from the standpoint of viscosity ; some lubricating fractions seem suitable for making satisfactory lubri- cating oils. The possible durability of such lubricating fractions in actual use is yet to be determined, and durability, after -all, is the property that deserves major emphasis in considering a lubri- cating oil. The setting points of the higher boiling vacuum fractions indicate that a good percentage of paraffin wax may be obtained from the shale oils examined. Similar setting points for fractions of the Scotch shale oils, shown on page 50, are of interest in this connection. On pages 48 to 50 inclusive are given Tables IX-A to IX-F showing the results of analytical distillations of the oils referred to. 48 SHORT PAPERS FROM THE TABLE IX-A. ANALYTICAL DISTILLATION OP SHALE OIL FROM COLORADO OIL-SHALE. Sample No. B-003 (81). Oil-shale from DeBeque, Colorado. First fraction off retort. Distilled in horizontal rotary retort. Retort temperature up to 269 Specific gravity oil, 0.937. Baume gravity, 19.4. Water in oil, 19.56 per cent. Setting point l Viscosity 1 Distillation, Bureau of Mines Hempel Method. Air distillation: barometer, 645 mm. First drop, 52 C. (126 F.). C. c si bD+J <- II rtj bfl ^ 3 l,e . 3 3 U Q, Q) &H Q ao 00 -*j .^ c ^3 O Pn ft H ga 5 P Up to 50 1 50- 75 0.34 0.34 75-100 .27 .61 1 i i 100-125 .95 1.56 125-150 3.22 4.78 150-175 3.87 8.65 0.817 41 4 50.6 175-200 4.83 13.48 .839 36 9 52.8 200-225 6.60 20.08 .858 33 2 i 225-250 7.48 27.56 .875 30. 55.8 250-275 10.54 38.10 .890 27. 3 57.8 Vacuum distilation at 40 i nm. Up to 200 200-225 2.55 7.75 2.55 10.30 .908 24 2 225-250 8.26 18.56 .931 20. 4 250-275 7.92 26.48 .941 18. 8 ** Residuum: specific gravity 1.015; setting point 45' *Not determined. C. Up to 122 122-167 167-212 212-257 257-302 302-347 347-392 392-437 437-482 482-527 44 i Up to 392 392-437 61 17.5 437-482 106 27.0 482-527 TABLE IX-B. ANALYTICAL^ DISTILLATION OF SHALE OIL FROM COLORADO OIL-SHALE. Sample No. B-002 (82). Oil-shale from DeBeque, Colorado. Second fraction off retort. Distilled in horizontal rotary retort. Retort temperature 269-285 ( Specific gravity oil, 0.984. Baume gravity, 12.3. Water in oil, 4.75 per cent. Setting point, 10 C. Viscosity, : . Distillation, Bureau of Mines Hempel Method. Air distillation: barometer 642 mm. First drop, 46 C. (114 F.) 0> Up to 50 t-i tr. Sum per cen t be! Is g a P tabc ea hi C Q) p | tD M E-t Up to 122 50- 75 0.51 0.51 J 122-167 75-100 f 0.768 52.3 46.0 167-212 100-125 l'.23 1.74 j 212-257 125-150 3.90 5.64 J 257-302 150-175 3.79 9.43 .803 . 44.4 49.6 302-347 175-200 5.07 14.50 .825 39.7 52.6 347-392 200-225 5.84 20.34 .843 36.1 i .. . 392-437 225-250 7.79 28.13 .866 31.7 54.6 '.'....'. 437-482 250-275 9.44 37.57 .884 28.4 59.0 482-527 Vacuum d: istillatioi i at 40 mm. Up to 200 200-225 2.67 7.90 2.67 10.57 } .906 24.5 43 Up to 392 392-437 225-250 8.26 18.83 .929 20.7 58 17 437-482 250-275 i Residuum: specific gravity 1.173; setting point i^ 'Not determined. CO-OPERATIVE OIL-SHALE LABORATORY 49 TABLE IX-C. ANALYTICAL DISTILLATION OP SHALE OIL FROM COLORADO OIL-SHALE. Sample No. B-004 (83). Oil-shale from DeBeque, Colorado. Third fraction from retort. Distilled in horizontal rotary retort. Retort temperature 285 322 C. Specific gravity oil, 0.918. Baume gravity, 22.5. Water in oil, 2.93 per cent. Setting- point, 19 C. Viscosity at 60 C., 56.' Distillation, Bureau of Mines Hemp el Method. Air distillation: barometer 640 mm. First drop 48 C. (118 F.) Sbo 3 3 . 3 hri ' 3 p 1 <* P, VI s } H Up to 50 tr. tr. ' 50- 75 0.271 0.27 75-100 .542 .81 0.772 51 A 100-125 1.35 2.16 125-150 3.39 5.55 . 150-175 | 175-200 j 8.12 13.67 .823 40 .1 200-225 4.57 18.24 .854 33 .9 225-250 6.17 24.41 .872 30.6 250-275 6.85 31.26 .893 26.8 Vacuum distillation at 40 mm. Up to 200 200-225 2.58 6,78 2.58 1 9.36 .914 23. 2 225-250 7.88 17.24 .923 21.7 250-275 8.27 25.51 .944 18 .3 Residuum: specific gravity 1.004; setting very asphaltic. Viscosity at 100 a c S-. HJ 3 O 49.0 59.0 point not Up to 122 122-167 167-212 212-257 257-302 302-347 347-392 392-437 437-482 43 S9 17.0 98 26.5 determined, 482-527 Up to 392 392-437 437-482 482-527 residuum F., 97. TABLE IX-D. ANALYTICAL DISTILLATION OP SHALE OIL PROM COLORADO OILuSHALE. Sample No. B-001 (84). Oil-shale from DeBeque, Colorado. Fourth cut from retort. Distilled in horizontal rotary retort. Retort temperature 599 C. Specific gravity oil, 0.901. Baume gravity, 25.4. Water in oil, 2.59 per cent. Setting- point 1 . Viscosity at 60 C., 65. Distillation, Bureau of Mines Hempel Method. Air distillation: barometer 645 mm. First drop 41 C. (106 F.) |S 3 fo ao c> 9? 02 t-> ao J t - M W C 0) c+ 'O o V W ft $ * *4J 4J ^ 5 P-i a M 5 ^> rt P 0) 99 Up to 50 50- 75 tr. 0.13 1 0.13 1 1 75-100 .32 .45 0.760 54.2 100-125 .99 1.44 > 28.0 125-150 1.66 3.10 J f 150-175 3.00 6.10 .785 48.3 175-200 6.12 12.22 .807 43.5 J 200-225 8.10 20.32 .826 39.5 } 225-250 6.65 26.97 .842 36.3 [ 34.0 250-275 8.47 35.44 .857 33.4 Vacuum distillation at 40 mm. Up to 200 9.32 9.32 .872 30.6 38 200-225 5.27 14.59 .881 28.9 40 225-250 7.16 21.75 .892 27.0 46 24*.*5 250-275 6.13 27.88 .902 25.2 52 29 275-300 6.07 33.95 .911 23.7 60 34 Residuum: specific gravity 0.957 (16.3 Be.); setting point 41 C. TABLE IX-F. ANALYTICAL DISTILLATION OF CRUDE OIL FROM PENNSYLVANIA. Pennsylvania crude oil. Specific gravity oil, 0.812. Water in oil, trace. Sample No. 0-009. Baume gravity, 42.4. Viscosity at 60 C., 39. Distillation, Bureau of Mines Hempel Method. Air distillation: barometer 644 mm. First drop 26 C. (79 F.) II IP Up to 50 50- 75 0.895 1.612 0.895 ) 2.507J 0.674 77.7 75-100 4.08 6.59 .712 66.6 100-125 8.29 14.88 .733 61.0 125-150 5.46 20.34 .752 56.2 150-175 6.77 26.11 .763 53.5 175-200 5.82 31.93 .778 50.0 200-225 6.95 38.88 .789 47.4 225-250 6.42 45.30 .800 45.0 250-275 7.46 52.76 .812 42.4 Vacuum distillation at 40 mm. Up to 200 3.33 3.33 .826 39.5 200-225 7.75 11.08 .832 38.3 225-250 6.02 17.10 .841 36.5 250-275 5.37 22.47 .848 35.1 275-300 5.16 27.63 .859 33.0 4.4 3.6 Residuum: specific gravity 0.882 (28.7 Be.); setting 39 40 45 51 67 point 15.5 22.5 30.0 18 C. UP to 122 122-167 167-212 212-257 257-302 302-347 347-392 392-437 437-482 482-527 Up to 392 392-437 437-482 482-527 527-572 CO-OPERATIVE OIL-SHALE LABORATORY 51 COMPARISON OP ANALYSES OF SHALE OILS. The prime purpose of this paper is to show by a presentation of experimental data- that the nature of the oils produced from the same shales at different temperatures during the same run changes to a certain extent, but that the change is so small that it is of little commercial importance. While this conclusion can be drawn from the four analyses presented in this paper, it is emphasized that the conclusion has not been reached as a result of these four an- alyses alone. In fact some fifty samples of oil produced at various temperatures have been examined, and in no case has a striking difference been found in the oils produced at different stages during the same retorting test. However, striking differences have been observed between oils produced in different runs when some definite retorting condition, such as rate of rise of temperature, has been varied. Tables IV-A to IX-F contain the records of analytical distilla- tions of the four samples of oil referred to. In addition they give the distillation of a sample of commercial Scotch shale oil produced from Scotch shale in Scotland. Also there is presented the dis- tillation analysis of a sample of high grade Pennsylvania crude oil. These last two analyses are inserted to show the difference between shale oil and petroleum, as indicated by distillations, and between shale oil produced in Scotland by commercial processes and the oil produced from Colorado oil-shale in the Boulder laboratory. It is important to note that the operations at Boulder are of an experimental nature. Often, in experimental work, negative results are as valuable as positive, since negative results indicate what not to do, or show that the experiments are going in the wrong direction. The oils herein reported, therefore, may not be the best oils that can be made from the shale. As a matter of fact, better oils are constantly being produced as better conditions are being determined and applied. At the Intermountain Experiment Sta tion of the Bureau of Mines, Salt Lake City, oils have already been produced by laboratory methods from Scotch shale that equal in every respect the shale oils produced in commercial operations in Scotland. So far, however, it has not been possible to produce equally satisfactory oils from American shales. A careful exam- ination of American oil-shales by chemical and microscopic means has indicated that it will be a difficult matter to produce oils from American oil-shales that are of as good quality as Scotch shale oils,* because of the differences in nature and origin of the different shales. Products from shales from different parts 1 of the United States, and even from different parts of the Green River forma- tion, show a marked difference although the shales were treated under identical conditions. 52 SHORT PAPERS FROM THE THERMAL CALCULATIONS ON THE RETORTING OF OIL-SHALES. INTRODUCTION. Engineers designing, or making calculations of capacities of oil-shale retorting equipment, will find it essential to determine the amount of heat necessary to retort a unit weight of a given shale. Also, it will often be desirable to know how much of that heat may be supplied by the shale gas and spent shale, either separately or in combination, or by fresh shale. Using data already available, or presented in other parts of this bulletin 1 , this paper presents calculations approximately indi- cating the following : A. The theoretical amount of heat necessary to retort an oil- shale at various temperatures. B. The total amount of heat necessary to retort an oil-shale at various furnace efficiencies. C. The furnace efficiencies necessary if retorting is to be car- ried on with the shale gas, or shale gas and spent shale, without the introduction of other fuel. METHOD OF MAKING CALCULATION OF HEAT REQUIRED FOR RETORTING. In order to obtain a set of figures- which might serve as a basis for estimating the value and suitability for retorting of shales of nearly any composition likely to be encountered, the following pro- cedure was used : The composition by weight (of residue, oil, water and gas) of four ideal shales calculated to represent probable average occur- rences in the Colorado-Utah district was estimated. These ideal types of shales produced oil at rates ranging from 25 to 100 gallons of oil per ton, and probably cover nearly all workable oil-shales in this district. The composition of these ideal shales is given in Table X. Having thus established the weights of each component of a set of shales having definite assays of oil, water and gas yield, the 'heat required for retorting was approximated as follows : 1. Certain assumptions were made. (a) A maximum temperature of retorting was as- signed. Cb) The specific heat of the shale was assumed not to vary up to 925 C. (c) A temperature was assigned as that of the begin- ning of the distillation. 1 Most of the factors necessary in making the calculations that follow have been given previously in publications of the authors or in this bulletin, and are summarized on page 62. CO-OPERATIVE OIL-SHALE LABORATORY 53 (d) The specific heat of the spent shale at compara- tively high temperature is assumed to be the same as that determined at a lower temperature. (e) The specific heat of the oil vapor is assumed to be very nearly that estimated for the oil at lower tempera- ture. (f) The .latent heat of vaporization of the oil is assumed to be nearly that of its lighter constituents. (g) The average specific heat of the permanent gases formed is assumed -to be 0.35. 2. Certain errors, at present partly unavoidable, are neg- lected. (a>) Those errors involved in the assumption regard- ing specific heats, above. (~b) Errors involved in considering that no vapors of either water or oil, or gases, are given off below the temperature assigned as that of the beginning of distilla- tion. (c) Errors involved in considering that all vapors originate at the temperature of the beginning of distilla- tion and are carried to the highest temperature of dis- tillation before discharge from the retort. (d) Errors involved in lack of quantitative informa- tion concerning the heat of decomposition or reaction of the shale kerogen, either positive or negative. The heat of reaction, however, is believed to be quite small. Notwithstanding the assumptions made, and the errors known to be introduced, the results of the calculations agree well with experimental facts as is shown below. 3. The various factors entering into the heat calculation were assembled, and the following formula obtained for calculating the amount of heat required to retort a unit of oil-shale by dry dis- tillation, at 100 per cent heating efficiency. The formula can be applied from the results of an assay on oil-shale in which oil and water yields and weight of spent shale have been determined, and weight of gas evolved arrived at by difference. Theoretical amount of heat, in small calories 1 , required to retort oil-shale by dry dis- tillation at 100 per cent efficiency = 454 \ S [ (T, T ) C'] + [r' -f (T 2 TJ C"] + W [r' ' + (To T t ) C" '] + G [ (T 2 T,) C' ' "] + R [ (T 2 TJ C" "] }' in which : 454 = factor for converting pounds into grams. (If the weights used are expressed as grams this figure is eliminated.) S = weight in pounds of shale considered. *If it is desired to convert this value into B.T.U.'s, divide the result expressed in calories by 252. 54 SHORT PAPERS PROM THE T = temperature of shale at start of retorting (usually atmospheric temperature) in degrees C. T! = temperature in degrees C. at which oil is first produced. T 2 = temperature in degrees C. at end of distillation. C' = average specific heat of fresh shale, between T and TI. (Here taken as 0.265). C' ' = average specific heat of oil vapors produced, between T x and T 2 . (Here taken as 0.6.) C' " = average specific heat of steam produced, be- tween Tj. and T 2 . (Here taken as 0.47.) C" ' = average specific heat of gas produced, be- tween T and T 2 . (Here taken as 0.35.) C" " ' = average specific heat of spent shale pro- duced, between T x and T 2 . (Here taken as 0.225.) r' = latent heat of vaporization of oil produced. (Here taken as 100.) r' ' = latent heat of vaporization of water produced. (540 calories per gram.) = weight of oil produced in pounds. W = weight of water produced in pounds. G = weight of gas produced in pounds. R = weight of spent shale (shale residue) in pounds. The following calculation is shown as an example, in which values for shale No. 3, Table X, are used. (For a summarized result on all the ideal shales considered, see Table XIV.) The shale yielded at the rate of 375 pounds of oil, 41.7 pounds of water, 1,383 pounds of spent shale, and 200 pounds of gas, de- termined by difference, all per ton of shale. The unit considered here is one ton. Substituting in the formula shown: 454 | 2000 [ (205 -- 15) 0.265] + 375 [100 + (482 - 205) 0.6] + 41.7 [540 + (482 - - 205) 0.47] + 200 [ (482 205) 0.35] +'1383 [ (482 -- 205) 0.225] j. = 149,272,000 calories or 593,000 B.T.U. In other words, the dry distillation of one ton of the shale under consideration, to 482 C. (900 F.), and recovering the quan- tity of products above set forth, would require 149,272,000 calories, or 593,000 B.T.U. of heat, if the retort were 100 per cent thermally efficient. Of course 100 per cent efficiency is never obtained, and therefore the above figure must, in practice, be multiplied by a factor based on the efficiency of whatever retort is used. I CO-OPERATIVE OIL-SHALE LABORATORY 55 COMPARISON OF CALCULATED AND EXPERIMENTALLY DETERMINED HEAT REQUIREMENTS. It is possible to apply the formula given to an experiment in which the actual amount of heat used in distilling an oil-shale was determined. Mr. Arthur J. Franks, of Golden, Colorado, working entirely independently of the authors, and without knowledge of the theoretical work being undertaken by the latter, has, by means of electrical measurements, roughly determined the amount of heat necessary to distil one ton of oil-shale. With his permission his experimental results and comments have been included: Retorting data: Weight of shale distilled, 10 pounds. Average temperature inside retort wall, 535 C. Time of retorting, 2 hours (7200 seconds). Estimated thermal efficiency of retort, 75 to 85 per cent. Heat measurements: Heat, electrical. Average voltage during test, 20. Average amperage during test, 30. Total watt seconds (20 X 30 X 7200) = 4,320,000. One watt second = 0.2389 small calories. 4,320,000 X 0.2389 = 1,033,000 calories for 10 pounds of shale, or 206,600,000 gram calories per 2,000 pounds, or 820,000 B.T.U. per ton of shale. Products obtained per ton of shale retorted : Oil, specific gravity assumed 0.900 at 15.56 C., 47.76 gallons or 357.9 pounds. Water, specific gravity assumed 1.000, 7.14 gallons or 59.5 pounds. Gas, assumed specific gravity 1.24 (air = 1.0), (gas contains 10.9 per cent C0 2 ), 3,260 cubic feet or 326 pounds. Spent shale, 1256.6 pounds. Substituting the above weights in the formula given : 454 \ 2000 [ (205 15) 0.265] + 537.9 [100 + (535 - 205) 0.6] + 59.5 [540 + (535 - - 205) 0.47] + 326 [ (535 205) 0.35] + 1256.6 [ (535 205) 0.225] j. = 170,064,000 calories or 677,000 B. T. U. It will be recalled that Mr. Frank's experiment indicated that 820,000 B.T.U. 's were required to retort a ton of the shale experi- mented with, and he estimated that the thermal efficiency of his retort was from 75 to 85 per cent. Assuming the above calculated value represents the heat required at 100 per cent retort efficiency, Mr. Frank's retort was 82.56 per cent efficient. Although this close agreement does not constitute a general proof of the reliability of the formula, or even an absolute proof for this specific case, it would seem to argue strongly in favor of 56 SHORT PAPERS FROM THE the applicability of the formula for at least approximations until such time as more complete data allows the development of a more exact expression. It is regretted that similar experimental data on shales of lower and higher oil yields are not obtainable to furnish bases for other confirmatory calculations, and the authors will greatly appre- ciate any authoritative data which may be used to test the accuracy of the formula, or to reduce the errors and assumptions known to be involved therein. CALCULATION OF HEAT AVAILABLE FROM SHALE GAS AND SPENT SHALE. From considerations developed in the paper on "Fuel Values of Shale and Shale Products, ' ' pages 13 to 21, the approximate heat- ing value of each of the ideal shales was calculated by multiplying the assay yield in gallons of oil per ton by the factor 106.6 to arrive at B.T.U. value per pound, and by 2000 X 106.6 for B.T.U. value per ton. The results of these calculations are shown in Table XI. From further considerations developed in the above mentioned paper, the percentage of heat found in each product was estimated, and also the heat per unit of each product. ( See Table IV, page 18, and discussion, pages 15 and 16.) Some slight adjustment by the method of trial and error yielded percentages which, upon being applied, gave heat values to units that checked within reasonable limits those determined experimentally. By applying these per- centages to the original heat values, the results presented in Tables XII and XIII were obtained. These figures indicate the amount of heat available in the products of retorting one ton of the ideal shales under discussion. THERMAL EFFICIENCIES OF RETORTS NECESSARY TO RETORT OIL-SHALES OF DIFFERENT RICHNESS. By applying the formula given on page 53 it is possible to determine the amount of heat required to retort the ideal shales discussed. Table XIV shows the results of such determinations, considering that the retorting is done in retorts of different heating efficiencies. Now having obtained figures approximating the total heat necessary for retorting the shales (Table XIV), and also the heat which may be obtained from the spent shale or shale gas, or both, (Table XIII), there may be calculated the absolute thermal effi- ciency necessary for a retort which is to handle any particular shale, by dry distillation, by burning either the shale gas, or shale residue, or both, with no additional fuel. Results of such calcula- tions for the ideal shales considered are given in Table XV. Both the fuel necessary to retort and that recoverable from the shale depend, of course, on the maximum temperature to which the shale is raised. Therefore results of two sets of calculations, one using a low and the other a high final retorting temperature, are included in Tables XIV and XV. All calculations are slide-rule estimations and therefore correct to the third significant figure. CO-OPERATIVE OIL-SHALE LABORATORY 57 TABLE X. COMPOSITION BY WEIGHT OF ONE TON OF SHALE. 1 Shale No. Fresh shale Lbs. Oil 2 Lbs. Water Lbs. Gas 3 Lbs. Residue Lbs. Assay Oil Gals, per ton Water Gals, per ton Gas Cuft. per ton 1 2000 187.5 41.70 125 1646.8 25.0 5.0 2500 2 2000 375.0 41.70 200 1383.3 50.0 . 5.0 4000 3 2000 562.5 .41.70 250 1146.8 75.0 5.0 5000 4 2000 750.0 41.70 250 958.3. 100.0 5.0 5000 1 Ideal assumed shales (see page 52). Specific gravity of oil assumed as 0.900. 3 Specific gravity of gas assumed as 0.656 (air 1); 1 cu. ft. gas weighs 0.05 Ibs. TABLE XI. TOTAL HEATING VALUE OF OIL-SHALES OF VARYING RICHNESS. Shale No. 1 Richness of shale gals, oil per ton Factor 2 B. T. U. per Ib. B. T. U. per ton. 1 25 106.6 2,665 5,330,000 2 50 106.6 5,330 10,660,000 3 75 106.6 7,995 15,990,000 4 100 106.6 10,660 ' 21,320,000 'Numbers refer to Table X. 2 See page 15. TABLE XII. HEAT VALUE OF PRODUCTS ON ONE TON OF OIL-SHALES OF DIFFERENT RICHNESS. Residue Gas Oil Shale No. ! Gals, oil per ton Total B. T. U. B. T. U. per Ib. Total B. T. U. B. T. U. per cu. ft. Total B. T. U. B. T. U. per Ib. 1 25 995,000 604 818,000 327 3,465,000 18,500 2 50 1,990,000 1,438 1,636,000 408 6,930,000 18,500 3 75 2,399,000 2,095 2,559,000 512 10,395,000 18,500 4 100 2,342,000 2,440 3,410,000 682 13,860,000 18,500 lumbers refer to Table X. 58 SHORT PAPERS FROM THE w S CO CO OO IM iH C . CO w C7i Ci CO CO m l ^i So t __"^ a 1 - 1 r""j w 00 CO 05 *^d n3 iH CO US r-> HH 2 o OO CO US * r/5 s i-T IM* CO L "^ CJ ^^ s o c US US "^ CO CO O5 CO $ s co" co o co" r- . rvi * P W )-H 1 1 ~ III PH- PH O o g 1 " 1 5_ O " - . OO CO CO W pa *S d U5 US iH N US CO CO us" o" us" 05" 2 I-H H W PH Hfc* wjfl ^o 1COVEBABL OFV^ c M * ffi ^-^ Is. lie C i-H EH ffio i 1 ^ t! ^2 H 0) i o a us o us o eg us c- o EH to ^ !^ 0) 2 g ^ 3 Ctf Q rH Tf rHOOt-O 02 {^ .^ ^ r^ ~ t- 2 *W O^ cfi O 05 ||||H COOOO "rt 03 ^ 2 EH & M^ 60 ^ P^ a ffi O EH -2 S "2 "S ^C . HH y) 3 2 s^^ P-H *jj 02 C ^ fn t>rHOO WrHOO GO) -^ o> o rt usoswus usose^us 3 ^ -u^cpq 0k O 09 M OSOIMCO m >, ^2^0 TH rH rH rH rH rH S "2 ^2 rH n TABLE XV. HAL EFFICIE* ,nd shale gas is th OS Necessary thermal efficiency of retort; per cent lousooos ousous mcocous COWOSIM 00 CO U w 1 0) W Sr^E-H oococous -^oococous O o TO" rH OS tO C 03 --^ sfp mouso usouso Ill's c-o c^usc^-o rH rH CO-OPERATIVE OIL-SHALE LABORATORY 61 CONVENIENT FACTORS FOR USE IN OIL SHALE CALCULATIONS. The purpose of this paper is to present factors frequently used in making oil-shale calculations, in a form which will per- mit their use by the field operator. The factors presented are for purposes of arriving at close approximations. All the figures in Table XVI are taken from Mark's "Me- chanical Engineer's Handbook." The table showing effect of altitude on atmospheric pressure (Table XXV) is taken from "Metallurgists and Chemists Handbook," by Liddell. The other tables and formulae are those used by the authors in the course of calculations made by them. They are in general merely appli- cations of well known principles to specific cases. The physical data for shales in Table XVII are those determined by the authors, most of them having been previously published. 1 Con- siderable care should be used in applying them as they were determined only for shales of a certain average richness from the Green River formation in Colorado. It is believed, however, that they may have rather wide application. TABLE XVI. FREQUENTLY USED EQUIVALENTS. Length. 1 centimeter 0.3937 inches. 1 inch = 2. 54 centimeters, (cm.) 1 meter =3. 281 feet. 1 foot = 0.3048 meters, (m.) 1 meter =1.0936 yards. 1 yard = 0.9144 meters, (m.) Areas. 1 acre = 43,560 square feet. 640 acres = 1 square mile. Volumes. 1 cubic inch = 16. 39 cubic centimeters, (cc.) 1 cubic foot = 1728 cubic inches, (cu. in.) 1 cubic foot = 28,352 cubic centimeters, (cc.) 1 gallons 231 cubic inches, (cu. in.) 1 gallon = 3785 cubic centimeters, (cc.) 1 gallon = 0.1357 cubic feet. (cu. ft.) 1 gallon = 0.004951 cubic yards, (cu. yds.) 1000 cubic centimeters = 1.0 liter. (1.) 1 liter = 0.03531 cubic feet. (cu. ft.) 1 cubic meter = 35. 3 cubic feet. (cu. ft.) Mass. 1 gram = weight of 1 cubic centimeter of pure water at 4 C. 28.35 grams (gm.)=l ounce, (oz.) 453.6 grams 1 pound (Ib.) 16 ounces. 1000 grams 1 kilogram (kg.) 2.205 pounds. Miscellaneous. 1 gallon of water (specific gravity = 1.0) 8.328 pounds 3780 grams. 1 cubic foot of water (at 40 C.) =62.428 pounds. 1 cubic foot of water (at 100 C.) =59.830 pounds. 1 pound of water. =0.12 gallons. 1 pound of oil (specific gravity 0.9) =0.1334 gallons. 1 barrel = 42 gallons =350 pounds of liquid of specific gravity l.OOO 1 . 1 ton of oil (specific gravity 0.9) = 5.72 barels. 1 barrel of liquid = 5.6154 cubic feet. 1 Gavin, M. J., and Sharp, L. H., Some physical and chemical data on Colorado oil-shale, Bureau of Mines, Reports of Investigations Serial No. 2152, August, 1920, 8 pp. lr To calculate pounds per barrel of any other liquid, multiply 350 by specific gravity of liquid. 62 SHORT PAPERS FROM THE TABLE XVII. SOME CONSTANTS FOR SHALE AND SHALE PRODUCTS. Fresh shale Spent shale Shale oil Specific heat 0.265 2 0.225 3 Calories per gram.... Assay in gal- Approximately Ions ner ton 0.2319 x heat 0.50.6 10,270 X59.25 value of fresh shale from which it was derived. B. T. U. per pound Latent heat of vaporization Assay in gal- Aonroximately Ions per ton 0.2319 x heat x 106.6 value of fresh shale from which it was derived. 18,500 100 Shale eras 1 Steam 0.35 4 Varies from 300 to 600 B. T. U. per cu. ft. at 0C., 760 mm. Water 540 0.47 'Produced from shale by dry destructive distillation. 2 Colorado oil-shale yielding 42 gallons of oil per ton. a Residue from Colorado oil-shale yielding 42 gallons of oil per ton. ^Approximately. TABLE XVIII. HEAT EQUIVALENTS. The calorie (small calorie or gram calorie) is the quantity of heat re- quired to raise the temperature of one gram of pure water fromi 4 to 5 Centigrade. The mean calorie, commonly used by engineers, and in this paper, is 1/100 of the quantity of heat required to raise the temperature of 1 gram of pure water from to 100 Centigrade. It is nearly the same as the amount of heat required to raise the temperature of 1 gram of pure water from 17 to 18 Centigrade. The large Calorie (kilogram Calorie) is 1000 times the small calorie, in whatever form the small calorie may be expressed. The British Thermal Unit (B. T. U. ) is the quantity of heat required to raise the temperature of 1 pound of pure water one degree Fahrenheit, at 39.1 F., the temperature of the maximum density of water. The Mean British Thermal Unit is 1/180 of the quantity of heat required to raise the temperature of one pound of pure water from 32 to 212 Fahrenheit. It is the term commonly used in American engineering practice. 1 B. T. U. 252 calories 0.252 kilogram Calories. 1 kilogram Calorie 3.968 B. T. U.'s. To change calories per gram to B. T. U. per pound, multiply by 1.8 (9/5). To change B. T. U. per pound to calories per gram, divide by 1.8 (or multiply by 5/9). TABLE XIX. TEMPERATURES. Fahrenheit scale (F.): Freezing point of water 32; boiling point of water = 212. Centigrade scale (C.): Freezing point of water water 100. Absolute scale (A.): Freezing point of water 273 water 373V To change temperature in To change temperature in To change temperature in To change temperature in To change temperature in To change temperature in boiling point of boiling point of F. to C.: (F. reading 32) X 5/9 = C. C. to F.: (C. readingX9/5)+32 = F. A.. C. reading+273 = A. C.: A. reading 273= C. A.: convert to C. then apply above. 'F. : convert to C. then apply above. >C. to A to D F. to A. to Absolute temperatures are sometimes expressed in Fahrenheit units in- stead of Centigrade units. Add 459 to Fahrenheit reading for this purpose. CO-OPERATIVE OIL-SHALE LABORATORY 63 TABLE XX. WEIGHT OF SHALE. (For approximations only.) Specific gravity of shale. Weight per cubic foot Pounds. Tons. Weight per acre per foot of thickness. 1.5 93.7 .04685 2040 tons 1.6 99.9 .04999 2176 tons 1.7 106.1 .05305 2310 tons 1.8 112.3 .05615 2445 tons 1.9 118.7 .05935 2583 tons 2.0 125.0 .06250 2721 tons 2.1 131.1 .06555 2858 tons 2.2 137.3 .06865 2990 tons 2.3 143.6 .07180 3124 tons 2.4 150.0 .07500 3265 tons 2.5 156.3 .07815 3405 tons Formula: 1 cubic foot 28,353 cubic centimeters. (1) Specific gravity X 28, 353 or (specific gravity X 62.5) = pounds per cubic foot. 454 (2) Pounds per cubic foot tons per cubic foot. 2000 (3) Tons per cubic foot X 43, 560 := tons per acre per foot of thickness. Weight of shale in place is much greater per cubic foot than when mined. Weight per cubic foot mined varies from, 0.42 to 0.5 of its weight in place according- to the size to which it is crushed. The finer the shale is crushed the greater its weight per cubic foot. One cubic foot in place when mined will yield 1 to 1 , i. e., 2.38 to 2.0 cubic feet. 0.42 0.5 TABLE XXI. 1 PETROLEUM OIL TABLE FOR CONVERTING SPECIFIC GRAVITY TO BAUME DEGREES. Specific gravitv 60/60F. Degrees Baume (Modulus 140) Pounds per gallon Gallons per pound 0.600 103.33 4.993 0.2003 .610 99.51 5.076 .1970 .620 95.81 5.160 .1938 .630 92 22 5.243 .1907 .640 88.75 5.326 .1877 .650 85.38 5.410 .1848 .660 82.12 5.493 .1820 .670 78.96 5.577 .1793 .680 75.88 5.660 .1767 .690 72.90 5.743 .1741 .700 70.00 5.827 .1716 .710 67.18 5.910 .1692 -720 64.44 5.994 .1668 .730 61.78 6.077 .1646 .740 59.19 6.160 .1623 .750 56.67 6.244 .1602 .760 54.21 6.327 .1580 .770 51.82 6.410 .1560 .780 49.49 6.494 .1540 .790 47.22 6.577 .1520 .800 45.00 6.661 .1501 .810 42.84 6.744 .1483 .820 40.73 6.827 .1465 .830 38.68 6.911 .1447 .840 36.67 6.994 .1430 .850 34.71 7.078 .1413 .860 32.79 7.161 .1396 64 SHORT PAPERS FROM THE PETROLEUM OIL TABLE FOR CONVERTING SPECIFIC GRAVITY TO BAUME DEGREES Continued. Specific gravity 60/60 F. Degrees Baume (Modulus 140) Pounds per gallon Gallons per pound .870 30.92 7.244 .1380 .880 29.09 7.328 .1365 .890 27.30 7.411 .1349 .900 25.56 7.494 .1334 .910 23.85 7.578 .1320 .920 22.17 7.661 .1305 .930 20.54 7.745 .1291 .940 18.94 7.828 .1278 .950 17.37 7.911 .1264 .960 15.83 / 7.995 .1251 .970 14.33 8.078 .1238 .980 12.86 8.162 .1225 .990 11.41 8.245 .1213 x This and the following- three tables are taken from United States Standard tables for Petroleum Oils, Circular 57, U. S. Bureau Standards, 1916, 64 pp. TABLE XXII. PETROLEUM OIL TABLE FOR CONVERTING BAUME DEGREES TO SPECIFIC GRAVITY. Degrees Specific Baume gravity (Modulus 60/60 140) F. Pounds per gallon Gallons per pound Degrees Specific Baume gravity (Modulus 60/60 140) F. Pounds per gallon Gallons per pound 10.0 1.0000 8.328 0.1201 55.0 0.7568 6.300 0.1587 11.0 .9929 . 8.269 .1209 56.0 .7527 6.266 .1596 12.0 .9859 8.211 .1218 57.0 .7487 6.233 .1604 13.0 .9790 8.153 .1227 58.0 .7447 6.199 .1613 14.0 .9722 8.096 .1235 59.0 .7407 6.166 .1622 JK.fl .^55 8 r ' 1 .1244 60.0 .7368 6.134 .1630 16.0 .9589 7.986 .1252 61.0 .7330 6.102 .1639 17.0 .9524 7.031 .1261 62.0 .7292 6.070 .1647 18.0 .9459 7.877 .1270 63.0 .7254 6.038 .1656 19.0 .9396 7.825 .1278 64.0 .7216 6.007 .1665 20.0 .9333 7.772 .1287 65.0 .7179 5.976 .1673 21.0 .9272 7.721 .1295 66.0 .7143 5.946 .1682 0< >.0 rpi 1 7 <"? ' .1304 67.0 .7107 5.916 .1690 23.0 !9150 7.620 .1313 68.0 .7071 5.886 .1699 24.0 .9091 7.570 .1321- 69.0 .7035 5.856 .1708 25.0 .9032 7.522 .1330 70.0 .7000 5.827 .1716 26.0 .8974 7.47^ .1338 71.0 .6965 5.798 .1725 27.0 .8917 7.425 .1347 72.0 .6931 5.769 .1733 28.0 .8861 7.378 .1355 73.0 .6897 5.741 .1742 ?9 .8805 7.35> .1364 74.0 .6863 5.712 .1751 30:0 .8750 7.286 .1373 75.0 .6829 5.685 .1759 31.0 .8696 7.241 .1381 76.0 .6796 5.657 .1768 32.0 .8642 7.196 .1390 77.0 .6763 5.629 .1776 33.0 .8589 7.152 .1398 78.0 .6731 5.602 .1785 ^4.0 .8537 7.108 .1407 79.0 .6699 5.576 .1793 35.0 .8485 7.065 .1415 80.0 .6667 5.549 .1802 ?fi .8434 7. '"?2 .1424 81.0 .6635 5.522 .1811 37.0 .8383- 6.980 .1433 82.0 .6604 5.497 .1819 38.0 .8333 6.939 .1441 83.0 .6573 5.471 .1828 39.0 .8284 6.898 .1450 84.0 .6542 5.445 .1837 40.0 .8235 6.857 .1459 85.0 .6512 5.420 .1845 41.0 .8187 6.817 .1467 86.0 .6482 5.395 .1854 42.0 .8140 6.777 .1476 87.0 .6452 5.370 .1862 43.0 .8092 6.738 .1484 88.0 .6422 5.345 .1871 44.0 .8046 6.699 .1493 89.0 .6393 5.320 .1880 45.0 .8000 6.661 .1501 90.0 .6364 5.296 .1888 46.0 .7955 6.62^ .1510 91.0 .6335 5.272 .1897 47.Q 7910 P 58fi .1518 92.0 .6306 5.248 .1905 48.0 .7865 6.548 .1527 93.0 .6278 5.225 .1914 49 .7821 6.511 .1536 94.0 .6250 5.201 .1923 50.0 .7778 6.476 .1544 95.0 .6222 5.178 .1931 51.0 .7735 6.440 .1553 96.0 .6195 5.155 .1940 52.0 .7692 8.404 .1562 97.0 .6167 5.132 .1949 53.0 .7650 . 6.369 .1570 98.0 .6140 5.110 .1957 54.0 .7609 6.334 .1579 99.0 .6114 5.088 .1966 55.0 .7568 6.300 .1587 100.0 .6087 5.066 .1974 CO-OPERATIVE OIL-SHALE LABORATORY 65 TABLE XXIII. 1 TEMPERATURE CORRECTIONS TO READINGS OF SPE- CIFIC GRAVITY HYDROMETERS IN AMERICAN PETROLEUM OILS AT VARIOUS TEM- PERATURES. (Standard at 60/60 p.) OBSERVED SPECIFIC GRAVITY Observed tempeiature 0.650 0.700 0.750 0.800 0.850 0.900 0.950 Subtract from, observed specific gravity 30 0.016 0.015 0.014 0.012 0.011 0.011 0.011 32 .015 .014 .013 .012 .011 .010 .010 34 .014 .013 .012 .011 .010 .010 .010 36 .013 .012 .011 .010 .009 .009 .009 38 .012 .011 .010 .009 .008 .008 .008 40 .0105 .0095 .0090 .0080 .0075 .0070 .0070 42 .0095 .0085 .0("80 .0070 .0065 .0065 .0065 44 .0085 .0075 .0070 .0065 .0060 .0060 .0055 46 .0075 .0065 .0060 .0055 .0050 .0050 .0050 48 .0065 .0060 .0055 .0050 .0045 .0045 .0040 50 .0050 .0050 .0045 .0040 .0035 .0035 .0035 52 .0040 .0040 .0035 .0030 .0030 .0030 .0030 54 .0030 .0030 .0025 .0025 .0020 .0020 .0020 56 .0090 0020 .0020 .0015 .0015 .0015 .0015 58 .0010 .0010 .0010 .0005 .0005 .0005 .0005 Add to observed specific gravity 60 .0000 .0000 .0000 .0000 .0000 .0000 .0000 62 .0010 .0010 .0010 .0005 .0005 .0005 64 .0020 .0020 .0015 .0015 .0015 .0015 66 .0030 .0030 .0025 .0025 .0020 .0020 68 .0040 .0040 .0035 .0030 .0030 .0030 70 .0050 .0050 ,0045 .0040 .0040 .0035 72 .0060 .0055 .0050 .0045 .0045 .0040 74 .0070 .0065 .0060 .0055 .0050 .0050 76 .0080 .0075 .0070 .0065 .0060 .0055 78 .0090 .0085 .0080 .0070 .0065 .0065 80 .010 .009 .008 .008 .007 .007 82 .011 .010 .009 .008 .008 .007 84 .012 .011 .,010 .009 .009 .008 86 .013 .012 .011 .010 .009 .009 88 .014 .013 .012 .011 .010 .010 90 .015 .014 .013 .012 .011 .010 92 .016 .015 .013 .012 .011 .011 94 .017 .016 .014 .013 .012 .012 96 .018 .016 .015 .014 .013 .013 98 .019 .017 .016 .015 .014 .013 100 .020 .018 .017 .015 .014 .014 102 .021 .019 .018 .016 .015 .015 104 .022 .020 .018 .017 .016 .015 106 .023 .021 .019 .017 .016 .016 108 024 .022 .020 .018 .017 .017 110 .025 .023 .021 .019 .018 .017 112 .026 .024 .022 .020 .019 .018 114 .027 .025 .022 .020 .019 .019 116 028 .026 .023 .021 .020 .019 118 .029 .026 .024 022 .021 .020 120 .030 .027 .025 .023 .022 .021 l lt is not definitely known that the figures in this table can be applied to shale oils, as the coefficients of expansion of shale oils are not known at present. Oils produced from different shales or under different conditions from the same shale, may have different coefficients, but it is believed that the above figures will apply for fairly close approximations in most cases It is possible that new tables must be worked out for shale oils. 66 SHORT PAPERS FROM THE TABLE XXIV. 1 TEMPERATURE CORRECTIONS TO READINGS OF BAUME HYDROMETERS IN AMERICAN PETROLEUM OILS AT VARIOUS TEMPERATURES. (Standard at 60 F. ; modulus 140.) OBSERVED DEGREES BAUME Observed 20.0 30.0 40.0 50.0 60.0 70.0 S 0.0 90.0 temperature ~~ deg. F. Add to observed degrees Baume 30 1.7 2.0 2.4 3.0 3.7 4.3 5.0 5.7 32 1.6 1.9 2.3 2.8 3.4 4.0 4.7 5.3 34 1.5 ^.8 2.1 2.6 3.1 3.7 4.3 4.9 36 1.4 1.6 2.0 2.4 2.9 3.4 4.0 4.6 38 1.3 1.5 1.8 2.2 2.6 3.1 3.6 4.2 40 1.2 1.4 1.6 2.0 2.4 2.8 3.2 3.8 42 1.1 1.2 1.5 1.8 2.2 2.5 2.9 3.4 44 .9 1.1 1.3 1.6 2.0 2.2 2.6 3.0 46 .8 .9 1.1 1.4 1.7 1.9 2.3 2.7 48 i .7 .8 .9 1.2 1.4 1.6 2.0 2.3 50 .6 .7 .8 1.0 1.2 1.4 1.6 1.9 52 .5 .6 7 .8 1.0 1.1 1.3 1.5 54 .3 A .5 .6 .8 .9 1.0 1.1 56. , 2 .3 .3 .4 .5 .6 .6 .7 58 !i .1 .1 .2 .3 .3 .3 .4 Subtract from observed degrees Baume CO .0 .0 .0 .0 .0 .0 .0 .0 62: .1 .1 .1 .2 .2 .3 .3 .4 6.4 .2 .3 .3 .4 .4 .6 .6 .7 66 .3 .4 .5 .6 .7 .8 .9 1.0 68 .5 .6 .6 .7 .9 1.1 1.3 1.4 70 j. .6 .7 .8 .9 1.1 1.4 1.6 1.7 72 .7 .8 .9 1.1 1.3 1.6 1.9 2.1 74 .8 .9 .1 1.3 1.6 1.8 2.2 2.5 76 .9 .1 .3 1.5 1.8 2.1 2.5 2.8 is : ; i 1.0 .2 .4 1.7 2.0 2.4 2.8 3.1 80 1.1 .3 .5 1.8 2.2 2.6 3.1 3.5 82 1.2 .4 .7 2.0 2.5 2.9 3.4 3.9 84 1.3 .5 1.8 2.2 2.7 3.2 3.7 4.3 86; 1.4 .7 2.0 2.4 2.9 3.4 4.0 4.6 88 : - 1.6 .8 2.1 2.6 3.1 3.7 4.2 4.9 90 1.7 2.0 2.3 2.7 3.3 3.9 4.5 5.2 92 1.8 2.1 2.4 2.9 3.5 4.2 4.8 5.6 94 1.9 2.2 2.6 3.1 3.8 4.4 5.1 5.9 96. 2.0 2.3 2.7 3.3 4.0 4.6 5.4 6.3 98 2.1 2.4 2.9 3.4 4.2 4.9 5.7 6.6 100 2.2 2.6 3.0 3.6 4.4 5.1 6.0 6.9 102 2.3 2.7 3.2 3.8 4.6 5.4 6.3 7.2 104 2.4 2.9 3.3 4.0 4.8 5.7 6.6 7.5 106 2.5 3.0 3.5 4.2 5.0 5.9 6.9 7.9 108 2.7 3.1 3.6 4.3 5.2 6.2 7.2 8.2 110 2.8 3.2 3.7 4.4 5.4 6.4 7.5 8.5 112 2.9 3.3 3.9 4.6 5.6 6.7 7.7 8.8 114 3.0 3.4 4.0 4.7 5.8 6.9 7.9 9.1 116 3.1 3.6 4.1 4.9 6.0 7.1 8.2 9.4 118 3.2 3.7 4.3 5.1 6.2 7.3 8.5 9.8 120 3.3 3.8 4.4 5.3 6.4 7.5 8.8 10. 1 a lt is not definitely known that the figures in this table can be applied to shale oils, as the coefficients of expansion of shale oils are not known at^ present. Oils produced from different shales or under different conditions from the same shale may have different coefficients, but it is believed that the above figures will apnly for fairly close approximations in most cases. It is possible that new tables must be worked out for shale oils. CO-OPERATIVE OIL-SHALE LABORATORY 67 TABLE XXV. RELATION BETWEEN ALTITUDE AND BAROMETRIC PRESSURE. 1 Altitude in feet .Barometer Atmospheric pressure Proportionate atmos* in inches in Ibs. per sq in. pheric density 0.00 30.0 14.72 1.00 500.0 29.5 14.45 0.98 1,000.0 28.9 14.18 0.96 1,500.0 28.4 13.94 0.94 2,000.0 27.9 13.69 0.93 2,500.0 27.4 13.45 0.91 3,000.0 26.9 13.20 0.89 4,000.0 26.0 12.75 0.86 5,000.0 25.1 12.30 0.83 6,000.0 24.2 11.85 0.80 7,000.0 23.3 11.44 0.77 8,000.0 22.5 11.04 0.75 9.000.0 21.7 . 10.65 0.73 10,000.0 20.9 10.26 0.70 'Liddell, D. M., Metallurgists and Chemists Handbook: 2d ed, 1918, p. 112. TABLE XXVI. FACTORS FOR USE IN CALCULATING RESULTS OF OIL SHALE ASSAYS. 1 Weight rf retort charge Weight of retort charge (J rams' Ounces Factor Grams Ounces Factor 1 2 3 1 2 3 10 .35 .042 310 10.94 1.294 20 .71 .083 320 11.30 1.335 30 1.06 .125 330 11.65 1.377 40 1.41 .167 340 12.00 1.419 50 1.76 .209 350 12.36 1.460 60 2.12 .250 360 12.71 1.502 70 2.47 .292 370 13.06 1.544 80 2.82 .334 380 13.41 1.586 90 3.18 .376 390 13.77 1.627 100 3.53 .417 400 14.12 1.669 110 3.88 .459 410 14.47 1.711 120 4.24 .501 420 14.83 1.753 130 4.59 .542 i 430 15.18 1.794 140 4.94 .584 440 15.53 1.836 150 5.29 .626 450 15.88 1.878 160 5.65 .668 460 16.24 1.919 170 6.00 .709 470 16.59 1.961 180 6.35 .751 480 16.94 2.003 190 6.71 .793 490 17.30 2.045 200 7.06 .835 500 17.65 2.086 210 7.41 .876 510 18.00 2.128 220 7.77 .918 520 18.36 2.170 230 8.12 .960 530 18.71 2.212 240 8.47 1.001 540 19.06 2.254 250 8.82 1.043 550 19.41 2.295 260 9.18 1.085 560 19.77 2.337 270 9.53 1.127 570 20.12 2.379 280 9.88 1.168 580 20.47 2.420 290 10.24 1.201 590 20.83 2.462 300 10.59 1.252 600 21.18 2.504 For any given weight of shale used (column 1 or 2), select the cor- responding factor in column 3; divide the number of cubic centimeters of oil collected by this factor to convert into gallons of oil per ton of shale. For shale charges whose weights in grams are not even multiples of ten, it will be necessary to interpolate to obtain the proper factor. 1 Prepared by L. C. Karrick, assistant oil-shale technologist, Bureau of Mines. 68 SHORT PAPERS FROM THE TABLE XXVII. OTHER FACTORS FREQUENTLY USED IN MAKING OIL- SHALE ASSAY CALCULATIONS. Imperial gallons per long ton to United States gallons per short ton .................................................................................... Multiply by 1.0716 Pounds per long ton to pounds per short ton ............................ Multiply by 0.893 Per cent nitrogen to pounds amonium sulphate per short ton ............................................ .......................................................... Multiply by 92.4 2,000 pounds=;907,185 grams. 1 Cubic foot = 28,377 cubic centimeters. cubic centimeters of gas obtained Cubic feet of gas per ton_-,32.037 X - gramB of 8ha ie retorted ~ , cubic centimeters of oil obtained Gallons of oil per ton = 239.66X - grams of ^ale retorted OVERDUE. Gaylamount Pamphlet Binder Gaylord Bros.. Inc. Stockton, Calif. T. M. Reg. U.S. Pat. Off. YC '18642 THE UNIVERSITY OF CALIFORNIA LIBRARY