PC-NRLF EXCHANGE Thermal Reactions in Carbureting Water Gas DISSERTATION SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN THE FACULTY OF PURE SCIENCE COLUMBIA UNIVERSITY BY Walter Frank Rittman, M.A., M.E. NEW YORK CITY 1914 Thermal Reactions in Carbureting Water Gas DISSERTATION SUBMITTED IN PARTIAL FULFILLMENT OF THE REQUIREMENTS FOR THE DEGREE OF DOCTOR OF PHILOSOPHY IN THE FACULTY OF PURE SCIENCE COLUMBIA UNIVERSITY BY Walter Frank Rittman, M.A., M.E. NEW YORK CITY 1914 ESCHENBACH PRINTING COMPANY EASTON, PENNA. 1914 - To GELLERT ALLEMAN PROFESSOR OF CHEMISTRY SWARTHMORE COLLEGE 305647 ACKNOWLEDGMENTS The author wishes to express his sincere apprecia- tion to Professor Milton C. Whitaker, at whose sug- gestion and under whose direct supervision this work was carried out; his practical advice and active co- operation have -been essential factors in the progress and development of this research. Thanks are due to Professor J. L. R. Morgan for assistance in the development of the theoretical dis- cussion; to Professor F. J. Metzger for suggestions as to methods of gas analysis and experimental pro- cedure; and to the other members of the chemical faculty for time given to informal discussions of the principles involved in the problem. W. F. RlTTMAN CHEMICAL ENGINEERING LABORATORY COLUMBIA UNIVERSITY, NEW YORK May. 1914 THERMAL REACTIONS IN CARBURETING WATER GAS PART I THEORETICAL Much careful scientific work has been done on the equilibria involved in the manufacture of uncarbureted blue water gas. In the combined processes of manu- facturing and carbureting blue water gas according to present practice, few experiments have been made on the equilibria of the constituents to find out the effect of varying pressure, temperature and concen- tration conditions. In the technical literature of gas manufacture, one rarely finds a reference to the rela- tionship which may exist between the spheres of re- action in the process. The natural conclusion has been that the water gas and oil gas reactions are sepa- rate and influence each other but little. It is proposed to consider some of the factors in which the H 2 , CO, CO 2 and H 2 O of the blue water gas may affect the proportions of CH 4 , C 2 He, C 2 H 4 , H 2 , etc., resulting from the cracking of the gas oil which is added. Likewise the influence of the gases coming from the oil on the percentage composition of the final gas mixture will be considered. When the blue water gas or oil gas are manufac- tured in separate operations, hydrogen is the only gas which is found in the free state, in any quantity. But if the two gases, separately made, should be brought together at high temperature in a container such as a gas plant superheater, would there not be new equi- libria to be satisfied? For example, might not the CO and Ho of one become CH 4 and H 2 O of the other, or vice versa? In case of these new equilibria, of course, there would be vital reactions between the gases of the two processes. In actual manufacturing practice, all the gases produced are in intimate contact at high temperature for the greater part of the manufacturing period, i. e., while passing through the carbureter and superheater. Is it then correct to regard carbureted water gas as the result of two distinct reactions? Equilibrium conditions tend to establish them- selves both during the periods of initial cracking of the oil and the subsequent passage of the mixture through the carbureter and superheater. Gas oil itself can be "cracked" in a short distance, as has d) been shown in practically all laboratory experiments; in the laboratory the length of the cracking tube is usually a question of inches. It would seem on a priori grounds that the only important reason for the existence of the superheater is to enable the various gases present to interact ("fix") and reach a favora- ble equilibrium. This laboratory has begun a comprehensive study of the reactions and equilibria involved in water gas manufacture. While unable to cover the field in two years, it has come to a full realization of the impor- tance of the investigation. The present paper will be confined to a theoretical consideration of the prob- lem. Further papers will take up experimental data. The problem has been attacked entirely from the point of view of physical chemistry, and from the standpoint of mass action and thermodynamics. In so doing, the mechanism of the reactions involved has not been seriously considered. The materials at the start, the final products desired, the energy transformations essential to bring the latter from the former, the temperature, the pressure and the concen- tration conditions favorable to the changes haVe had primary consideration. Basing an experimental investigation upon the theoretical considerations evolved, it has been possible, among other things, to establish the following results: (1) Increase the yield of illuminants over the best results recorded in the literature by more than 100 per cent. (2) Decrease the carbon deposited to less than i per cent, by weight, of the oil used. (3) Make an oil gas in which 56 per cent of the fixed gases are illuminants. These figures result from the application of condi- tions which the theory shows would favor such results more than do those at present used in water gas manu- facture. Conversely by applying conditions, which, according to theory would give less favorable results to the theory involved, and by comparing the maximum yield under these conditions with a maximum yield obtained under ordinary conditions, it has been found possible to: (4) Decrease the yield of illuminants by 25 per cent. (5) Increase the carbon deposited to 51.5 per cent, by weight, of the oil used. (6) Make an oil gas containing only 5 per cent total illuminants. (2) Further, it has been found possible to produce: (7) A viscous tar of relatively high specific gravity containing naphthalene and anthracene; or (8) A liquid "tar" of relatively low specific gravity resembling petroleum oil, and containing no naphtha- lene and anthracene. In the examination of the problem, no single reaction can be considered exclusively by itself. All the reactions are vitally interrelated, though any single reaction, or set of reactions, may be extremely important as indicating a tendency. The experiments are designed to obtain the largest yield of hydrocarbons, and to eliminate, as much as possible, CO 2 , water vapor, deposited carbon, and tar vapors. The goal is to in- crease the yield of illuminants. MANUFACTURE OF UNCARBURETED BLUE WATER GAS The manufacture of blue water gas may be repre- sented by the equations: C + H 2 = CO 4- H 2 29,300 cal. (i) C -f 2H 2 O = C0 2 4- 2H 2 19,000 cal. (2) The two equations are combined by subtracting (2) from (i) in order to eliminate the carbon: CO 2 + H 2 = CO 4- H 2 O 10,300 cal. Equilibrium is established between these gases when where K represents the usual equilibrium constant; i. e., the value of the product of the partial pressures of CO and H 2 divided by the product of the partial pressures of CO 2 and H 2 . K has a definite value for each definite absolute temperature. For a practical illustration of the significance of equilibrium conditions in the manufacture of blue water gas, assume a theo- retically ideal mixture consisting of 50 per cent H 2 and 50 per cent CO. Pass the two gases through a chamber heated to 715 C. (1319 F.) until they reach the equilibrium of this tempera- ture; what are the resulting gases? K at this temperature is in the neighborhood of 0.30. 3CO 4- H 2 = C0 2 4- H 2 + 2C 4- 68900 cal. Under equilibrium conditions at atmospheric pressure Let X - volume COz then X = volume H 2 O 0.5 X = volume Hz 0.5 3X = volume CO 2X = total final volume (3) ( 1 _ 2X ) 1 = partial pressure QO-i ~~TJ l = partial pressure H 2 ) 1 = partial pressure H 2 O ( -j-I ) 1 = partial pressure CO M 2X/M 2X/ /0.5 3X\/0.5 Xx (0.5 3X)3 V 1 2X } \ 1 2X / 2XH1 2X) Solving, X = 0.069 = 6.9 per cent 2X = gas lost in reaction = 13.8 per cent 0.069 -<-<> Applying the above calculations to a mixture of 1,000 cu. ft. each of carbon monoxide and hydrogen, and assuming that no hydrocarbons are formed, there would be a net loss of 13.8 per cent (276 cu. ft.) due to the reaction, leaving 1,724 cu. ft. of mixed gases, as follows: 1724 X 0.08 = 138 cu. ft. CO 2 1724 X 0.08 = 138 cu. ft. H 2 O 1724 X 0.34 = 586 cu. ft. CO 1724 X 0.50 = 862 cu. ft. H 2 The water in condensing leaves a net volume of permanent gases equal to 1724 138 = 1586 cu. ft. This permanent gas is composed of 8.7 per cent CO 2 , 37 per cent CO and 54.3 per cent H2. ThEre would be also a deposit of 9.25 pounds of car- bon. In other words, there are only 1586 138 = 1448 cu. ft. of the original H 2 and CO remaining. Different temperature conditions would obviously give different results. A numerical problem of this nature shows how vitally equilibria conditions influ- ence gas manufacture, and indicates the commercial importance of an understanding of such equilibria conditions. Just as the equilibria conditions here are of importance, it can be shown that they are no less important when the reactions are between CO, H 2 , CO2, and H 2 O coming from the blue water gas on one hand, and H 2 , CH 4 , C 2 H 6 , C 2 H 4 , and tar vapors, etc., coming from the gas oil on the other hand. The blue water gas reactions and equilibria have been investigated 1 and are well understood, so that we know i Bureau of Mines, Bulletin 7, 1911; Juptner, Chem. Ztg., 1904, p. 902; K. Neuman, Stahl und Eisen, 1913, p. 394; O. Hahn, Z. physik. Chem., 44, 513-547; C. LeChatelier and K. Neuman, Stahl und Eisen. 1913, p. 1485; E- A. Allcut. Engineering, 1911, p. 601. (4) what conditions are favorable and what are unfavora- ble; i. e., degree of temperature, quantity of steam, depth of fuel bed, etc. MANUFACTURE OF STRAIGHT OIL GAS The manufacture of an oil gas as carried out by the Pintsch or Blau Gas companies is an old process, but is not as well understood as the blue water gas equilibrium. Few experimental equilibria of the various components of oil gas have been worked out, as have been the CO 2 , CO, H 2 and H 2 relations of blue water gas. Here, one at once faces the fact that in the oil cracking process, instead of the four gases of the blue water gas reaction, there are all the members of the methane, ethylene and acetylene series, as well as those hydrocarbons which consti- tute the tars produced in pyrogenetic decomposition. Synthetic methane has been made from carbon and hydrogen, 1 where equilibrium exists when Similarly, we may conclude that equilibrium exists between H 2 and all of the other hydrocarbons. By combining the ethane and ethylene equations through the elimination of carbon, one gets C 2 H 6 = C 2 H 4 -f- H 2 , where equilibrium conditions prevail when For a practical illustration of the meaning of this ex- pression, take the effect of heat on a known volume of C 2 H 6 . Eliminating other reactions than the one between ethane and ethylene, consider the resultant relative quantities of H 2 , C 2 H 6 and C 2 H 4 at a temperature of 900 C., taking the value of K equal to i. 28. C 2 He = C 2 H 4 -\- H 2 Let X = volume H2 then X = volume C2H4 1 X = volume C 2 H 6 1 + X = total final volume = partial pressure C2H* = partial pressure X 1 -p X . = partial pressure H2 1 ~t~ .X. 1 Pring and Fairlie, Report of Eighth International Congress; Ipatiew, Jour, prakl. Chem., 1913, pp. 479-487; Pring and Fairlie, Jour. Ghent. Soc., 1906 p. 1591; Ibid., 1911, p. 1796; Ibid., 1912, pp. 91-103; Bone and Coward, J. Chem. Soc., 1908, p. 1975. Proc. Chem. Soc., 1910, p. 146. (5) j, M_+x'M + x' x* A. = 1.20 = _ - Solving, X = 0.75 ~^= 42.85percentC 2 H 4 , ^- 5 = 42.85 per cent Hz and -1-- = 14.30 per cent CzH 6 . In dealing with any of these equilibria expressions, one must be careful to remember that no single equi- librium can be considered by itself. In the ethane- hydrogen-ethylene equilibrium at 900 C., for instance, there is a pronounced tendency for the ethane to go to ethylene; and in practice one should expect, therefore, a high ethylene yield, but by referring to the ethylene benzene system one finds that at 900 C. there is an even greater tendency for the ethylene to be removed by polymerization to benzene. Assuming a volume of C 2 H 4 and bringing it to equilibrium at 900 C., observe the resultant relative quantities of C 2 H 4 and C 6 H: 3C 2 H 4 = CeH 6 + 3H 2 -f 32500 cal. Under equilibrium conditions at atmospheric pressure X = volume CeHe 3X = volume H 2 1 3X = volume C 2 H 4 X = total final volume 2 = partial pressure of CeHe = partial pressure C 2 H4 = partial pressure of H 2 1 ~r X v ^"V" 3 K Pcsnt P 3 Hj M + X M + X' K = -, = 68 X 10 = - ( . Solving, X = 0.33 . ' H = 24 . 8 per cent C 6 H 6 , ^^ = 74 . 4 per cent H 2 1 . o<5 1 . 33 and J*?J = 0.8 per cent C 2 H 4 . Thus an experimental test, with the yield calculated according to the first equilibrium without a consideration of the second, would result in disappointment. Further, not only must the ethane-hydrogen-ethylene- benzene equilibrium be satisfied, but each of these con- stituents, in turn, must be in equilibrium with methane, acetylene, propane, naphthalene, etc. In short, there will be a grand symphony of equilibria between all components of the system. (6) Equilibria expressions, such as the ones just given, are therefore of value when properly understood and used as a basis for experimental proof. First of all, the time element is very important to insure final equi- librium; and secondly, their mathematical derivations involve integration factors based on physical proper- ties such as specific heat, vapor pressure, heat of reac- tion, etc., under conditions which have not been experimentally determined. Experimental demonstra- tion based upon a few selected and isolated equilibria is almost certain to result in failure, due to overlooking other equally important equilibria which might modify or even reverse the direction of final reactions. Sufficient experimental and commercial work has been done on the making of all oil gas under atmospheric conditions 1 to give empirical data indicating that as the temperature goes above 800 C. the yield of hydrocarbons rapidly decreases; on the other hand, the hydrogen and carbon rapidly increase. CARBURETED WATER GAS PROCESS In the carbureted water gas practice, as carried out to-day, there is a combination of the blue water gas and the oil gas process. Much is known about the blue gas; it is also known that this blue gas is carbureted by spraying in and cracking oil which furnishes the hydrocarbons and illuminants. There is little scien- tific information, however, regarding the interactions and equilibria which are reached when the two processes are combined. The formation of hydrocarbons and water from CO and H 2 or from CO 2 and H 2 is not theo- retical speculation; 2 likewise the destruction of hydro- carbons with water to form CO and H 2 or CO 2 and H 2 , as carried out in the all oil water gas process, is not theoretical speculation. Whichever course prevails depends entirely upon conditions. Consequently, one is justified in concluding that the present composi- 1 Haber and co-workers, Jour. Gasb.. 189$, pp. 377, 395, 435, 452; Hempel, Dissertation. Jour. Gasb., 1910, pp. 53, 77, 101, 137, 155. 2 Mayer, Henseling and Altmayer. J. f. Gasb., 1909, pp. 166, 194, 238, 326; P. Sabatier, Chem. Ztg., 1913, p. 148; P. Sabatier, Fr. Patent 355,325, 1905; Ibid., 355,900, 1905; Ibid.. 361,616; Ibid., 400,656; Eng. Patent 14,971, 1908; Ibid., 27,045; L. Vignon, Fr. Patent 416,699, 1909; Compt. rend., 1913, pp. 131-134; Gautier, /& 2CO + 4Ht K = (CO) 2 X (H 2 )4 C 2 H 4 X (H0) 2 C 2 H 2 + 2H 2 "7~^ 2CO + 3H 2 K = ( C ) 2 X (H 2 ) CiH X (H 2 O)z FAVORABLE WHEN CO AND H 2 ARE LARGE AND H 2 O is SMALL B CH 4 + 2H 2 7"^ COi + 4H 2 K = c 2 X (H 2 ) CH 4 X (H0)2 C 2 H4 + 4H 2 "T"** 2C0 2 + 6H 2 K = (CQ 2 )2 X (H 2 ) C 2 H4 X (HzO) C 2 H 2 + 4H 2 O * 2CO 2 + 5H 2 K = ( co *) 2 X (H 2 )s = CiHj X (H0)4 FAVORABLE WHEN CO 2 AND H 2 ARE LARGE AND H 2 O is SMALL C CH 4 + CO 2 ^ ^ 2CO + 2H 2 = (CO) ^ X (H 2 )2 C0 2 X CH4 C 2 H 4 + 2CO 2 ^ ^ 4CO + 2H 2 = (C0) X (Hi) CjH 4 X (CO*)* CH 2 + 2CO 2 ^ ^ 4CO + H 2 X H 2 X (CO 2 ) FAVORABLE WHEN CO AND H 2 ARE LARGE AND CO 2 is SMALL (9) The original complex state of affairs is thus partially simplified. One sees that conditions favorable to the formation of hydrocarbons, or at least unfavorable to the decomposition of hydrocarbons, exist when in A, B and C there is an excess of H 2 , A and C, there is an excess of CO, A and B, there is a minimum of water vapor, B, there is an excess of CO2, C, there is a minimum of CO 2 . An excess of hydrogen is favorable under any condi- tions; a minimum of water vapor is favorable under any conditions; an excess of CO appears to be favora- ble under any conditions; in the case of CO2, however, one condition indicates an excess as favorable whereas another indicates an excess as unfavorable. INFLUENCE OF TEMPERATURE ON EQUILIBRIUM CONDI- TIONS While these qualitative relations are extremely valuable in the consideration of favorable conditions, they do not give a sufficiently concrete idea of the conditions which prevail at different temperatures. Each equilibrium constant has a definite value for a definite temperature. If this value of K is considered for 500 C. the reaction may proceed in one direction; whereas on considering the value of K' for the same reacting agents at 900 C., the reaction may proceed in the opposite direction. Qualitative expressions point merely in general directions and give no ideas as to maxima or minima in the curve of favorable conditions. As an example, consider the equilibrium Pent Pmo where K equals approximately o.ooi for 500 C.; at 900 C. the equilibrium constant for the same re- lationship has the approximate value K' 346, or 346,000 times as great. This illustrates the importance of getting numerical values for the constants expressing equilibrium conditions for the various gases, even though they be approximate. From a consideration of the CO, H 2 , CH 4 , and H 2 O equilibrium, it appears that excesses of H 2 and CO would be favorable to the formation or preservation of hydrocarbons both at 500 C. and 900 C. It will further appear, however, that at 900 C. the excess of H 2 and CO to stimulate the reaction towards hydro- carbons will have to be enormous, while at 500 C. do) it need be only moderate. This can be seen from a mathematical study of the equilibrium, purely aside from the chemistry involved. At 500 C. the denominator is obviously the predominant factor. At 900 C. the numerator has become the predominant factor. In fact the situation is so different that it would take many times as much H 2 and CO at 900 C. as it would at 500 C. Taking the two equilibrium constants and calculating theoretical mixtures one obtains the following contrasting results: CH 4 + H 2 O ^ CO + 3 H 2 X = final volume CO /i (1 4X) = final volume CH4 3X - final volume H 2 / (1 4X) = final volume H Z O K = Temp. C. 500. 900. PCO P 3 H2 108 X* PCH4 0H20 16 X' 8X + 1 Percentages 0.001 . 346 CO H 2 CH 4 5 15 40 24.3 72.9 1.4 HiO 40 1.4 The water vapor of these equilibria is usually not considered in practice because it never appears in either the gas of the tank holder or in the gas sampling tube and resulting analysis. This does not prove its absence in the machine. Also equal pressures of hy- drogen and CO in a given system are not necessarily of the same influence. This is shown in equilibrium conditions for the CH 4 , H 2 0, CO and H 2 system, where for instance the concentration of H 2 is raised to the third power, while that of CO is of the first power. In manufacturing practice the total pressure is approximately one atmosphere, the partial pressures are expressed by such decimals as 0.5. The third power of 0.5, or 0.125, is much less than the first power, 0.5. Examples to show the effect of temperature crn the state of equilibrium can be found in straight hydro- carbon reactions. The equilibrium between acetylene and benzene shows the following results: 600 C 900 C 2000 C K = ,^'J?' 9 X io 23 1.2 X io 13 6 X io- 4 ((^ztizr It appears that the value of K' at 2000 C. is 1.5 X io 27 times as great as the value of K at 600 C. This leads to the expectation that while at 600 C. all the acetylene tends to polymerize to benzene, (n) at 2000 C., under proper conditions of pressure, benzene tends to depolymerize to acetylene. In the equilibrium existing between ethane and ethylene, C 2 H 6 = C 2 H 4 + H 2 37900 cal., the value of K' at 900 is approximately 1.28, whereasthe value of K at 150 is approximately 0.00000000000007. Ethane at 900 C. has a pronounced tendency to go to ethylene; the tendency for the ethylene to combine with hydrogen at 150 C. to form ethane is even more pronounced. The relatively small amount of ethane in oil gas made at 900 C. would seem to verify the first equilibrium constant; the large yield of ethane through the reduction of ethylene with hydrogen in the presence of palladium at 150 C. in- dicates the second constant. EFFECT OF PRESSURE ON GASEOUS REACTIONS In passing from ethane to acetylene, C 2 H 6 = C 2 H 2 + 2H 2 , there is an increase in volume; on the other hand, when acetylene polymerizes to benzene, 3C 2 H 2 > C 6 H 6 , there is a decrease in volume. According to the principle of LeChatelier one would not expect the same pressure conditions to be favorable to both. Again, the information is qualitative and gives no concrete idea of the relative influence of one-third atmosphere when added to one atmosphere pressure absolute as compared to adding the same one-third atmosphere to ten atmospheres pressure absolute. As a type reaction consider B 2 A > 26 where K = - A For numerical illustration, assume the value of K to be equal to i (any other value serving equally well). From this, one finds for partial pressures, when A = 100, B = 10 or when A = o.oi, B = o.i. In the first case the partial pressure of A is ten times as great as that of B; in the second case the partial pressure of A is only one-tenth as large as the partial pressure of B. In other words, by simply changing the total pressure on the system and keeping all other conditions constant, the ratio of A to B for the pressures shown has been divided by 100. By taking the first differential of the relationship, and equating it to o, B 2 B 2 dA 26 K = A= = = o ,B=o A K dE K (12) one sees there is a maximum or minimum in the ratio of A to B as zero pressure is approached. By taking the second differential " h K one finds the sign to be positive, indicating that the partial pressure of A as compared with the partial pressure of B approaches a minimum as the pressure approaches the absolute zero; or conversely there would be a maximum relative yield of B the closer one approached zero pressure absolute. The rate of change can best be seen by determining points for the parabola, B 2 = KA, and plotting the resulting curve. 1 0%A,100%B 1007.A.07.B .l^tJ .3 1 '"* Total Pressure in Atmospheres FIG. I REACTION ISOTHERM The general relationship of B to A changes only in degree the greater the change in the number of volumes, as can be seen by considering the curve for A-3B, 0%A,100%B 100%A,0%B J J44 S Total Pressure in Atmospheres FIG. II REACTION ISOTHERM 1 Since most of the values of K encountered in the practical study of the problem were represented by decimals, Curves I and II were plotted on the basis of K == 0.1. (13) From the curves shown, one can readily see that the effect of reducing pressure from one atmosphere to two-thirds of an atmosphere gives an advantage which is of little practical consequence when compared with the advantage gained by the same reductions when nearer the absolute zero of pressure. One-thirtieth of an atmosphere added to one-thirtieth atmosphere pres- sure doubles the total pressure on a system just as effectually as an increase from 100 to 200 atmospheres. EFFECT OF CONCENTRATION IN GASEOUS REACTIONS The addition of an end product in any decomposition or dissociation process, such as PCls > PCla + Clj NH 4 C1 > NH 3 + HC1 2SO 3 > 2SO 2 + O 2 2NH 3 > N 2 + 3H 2 checks the decomposition or dissociation. In other words, less PC1 5 will dissociate in an atmosphere of chlorine than in an atmosphere of nitrogen or air. Ammonium chloride when heated in an atmosphere of ammonia will not dissociate to the same extent as in a vacuum or in an atmosphere containing neither arhmonia nor hydrochloric acid gas. Likewise it would be expected that ethylene would not decompose to the same degree when subjected to a high temperature in the presence of hydrogen as when subjected to the same temperature in an atmosphere of nitrogen. Further, if the ethylene were subjected to the same high temperature in the presence of both hydrogen and methane, these two constituents in the ethylene- methane-hydrogen equilibrium could be in excess; as a result, less of the ethylene should be decomposed in the formation of methane and hydrogen. In the same way if petroleum is cracked in an atmosphere con- taining all the hydrocarbon gases with the exception of ethylene, one would expect all the fixed gas coming from the petroleum to be ethylene, at least until the ethylene content of the system is sufficient to conform to the equilibrium conditions. The consideration of these principles seems to question the necessity of using valuable gas oil in continually generating new end products, such as tar and hydrogen; if they could be artificially supplied the equilibrium conditions would be satisfied without producing new decomposition and polymerization end products. COMBINED INFLUENCE OF PRESSURE AND CONCENTRA- TION ON GASEOUS REACTIONS Theoretical consideration of the effect of pressure (14) on gaseous reactions indicates that an increased yield of gaseous hydrocarbons will be obtained as the total pressure on the system approaches zero; also an in- creased yield of illuminants will be obtained by crack- ing the oil in an atmosphere of end products such as hydrogen and methane. On combination the logical conclusion is that one should obtain the maximum yield of illuminants by cracking the petroleum at low pressures and in an atmosphere of end products. Upon first consideration one might reasonably ques- tion the idea of adding hydrogen or methane to a vacuum, but this investigation deals with relative partial pressures, regardless of whether the total pressure equals fifty atmospheres or one-fiftieth of one atmosphere absolute. INFLUENCE OF CATALYSTS ON GASEOUS REACTIONS Catalytic agents such as platinum, palladium, cobalt and nickel do not, in any way, influence final conditions of equilibrium; they merely hasten the rate at which the system reaches its final equilibrium. Whereas ethylene and hydrogen do not combine to an appreciable degree when heated to 100 C. in the absence of a catalyzer, the same mixture passed over colloidal palladium heated to 100 C. unites to form a considerable percentage of ethane. Likewise CO and H 2 or CO2 and H 2 can be in intimate contact at 200 to 300 without appreciable reaction in the formation of methane, but when the same proportions are brought together in the presence of a catalytic agent such as nickel or cobalt there is a very large yield of methane and water. 1 Vignon 2 finds that lime has much the same effect on the combination of CO and H2. THE VAN'T HOFF DIFFERENTIAL EQUATION SHOWING THE RELATION OF K TO K' To all students of physical chemistry the proposi- tion of Berthelot and Thomson that "every chemical change gives rise to the production of those substances which occasion the greatest development of heat" is familiar. Were this true, it would be easy to pre- dict which of two given reactions would take place at a given temperature. Chemists today recognize 1 Mayer, Henseling and Altmayer, Jour. f. Gasb., 1909, pp. 166, 194; Jockutn, Ibid., 1914, pp. 73, 103, 124, 149; Orlow, Jour. Russ. Phys. Chem., 1908, p. 1588. 2 Vignon. I,., Compt. rend., 1913, pp. 131-134. (15) the fallacy of the statement because in all chemical reactions one deals with the additional so-called " latent energy." Berthelot's principle disregards this molecular energy, and assumes the free energy, termed maximum work, to be equal to the total energy change. Nernst maintains that this is true only at the absolute zero, i. e., the entropy of liquids and solids at absolute zero temperature equals zero. The van't Hoff equation showing the relation be- tween K and K' is expressed by (log, *,) = or d (log, *,) = Upon integration this becomes log, ** = RT + constant Were it a simple matter to determine the value of this constant of integration, as well as the value of q at the different temperatures (in other words integrate the expression to absolute units) this would consti- tute a mathematical expression for what many consider a third law of thermodynamics. As yet there is no such accepted integration, and the best solution is to use approximate expressions, remembering at all times that the expressions are approximate, and making intelligent use of them as such. It is possible to avoid the constant of integration, however, by inte- grating between limits p' and p to log, K p > log, K p = 9 ~ (~ ^) This integrated expression is extremely important in determining the value of K' for any desired tempera- ture after the value of K for any other temperature has been experimentally determined. It is also valu- able in showing relationships between K and K' for two different temperatures, where neither has been determined, but in this case it expresses relation- ships and not direct values. For instance, assume that one wished to find the relationship between K and K' for the reaction 2C + H 2 = C 2 H 2 58100 cal. at the temperatures 600 and 900 C. log, *,, - log, K t - - - = 8. 49 (16) log e K P = 8.49 or, logio ^~ = 3-69 whence Keoo = ~ 4900 THE NERNST APPROXIMATION FORMULA FOR K Even though correct, K is a value based on the as- sumption that sufficient time elapses to allow the sys- tem to reach complete equilibrium. When dealing with hydrocarbons at different temperatures, this must not be overlooked. In fact the time element is of such primary moment that numerically correct values for K would be of little more practical use in gas manufacture than approximate values. In the case of reacting gases one does not have the speed conditions that ordinarily exist in solutions. On the other hand, gases brought together at sufficiently high temperatures do reach equilibrium practically instantly. It is important to bring out these limita- tions despite the value of approximate quantitative expressions such as the Nernst formula; the latter is of immense value in predicting the tendency of a reac- tion. In this paper Nernst 's formula is merely used; its derivation with comments can be found in the seventh German edition of Nernst 's " Theoretical Chemistry," Jellinek's " Physikalische Chemie der Gasreaktionen," or Sackur's " Thermochemie und Thermodynamik." log K = --= + 2v 1.75 log T + ZvC 4-57 1 -1 where q is the heat developed at ordinary tempera- tures and under constant pressure, as taken from thermochemical tables; 2z> represents the volume changes, and 2^C represents a summation of constants. These constants are given as follows: H 2 1.6 C 2 H 6 2.6 C 2 H 2 3.2 CO 3.5 H 2 O 3.6 CH 4 2.5 C 2 H4 2.8 C 6 H 6 3.0 COj 3.2 O 2 2.8 To use Nernst's words, the equation gives a "fairly accurate" idea of the state of equilibrium in a system. The approximation is applied in this fashion: C + 2H 2 = CH 4 -f 18900 cal. + 18900 log Keoo = 4 7 5 y i 8?3 1.75 log 873 0.7 = 1 . 1 1 = 2.89(a) + 18900 logKTso - ?1 x 1Q23 1-75 log 1023 0.7 = 1.93 = 2.07 + 18900 log Koo = 457i~^77Y73~ 1.75 log 1173 0.7 = 2.55 = 3.45 whence, Keoo = 0.077 KTSO - 0.012 K 9 oo - 0.003 (a) Negative logarithms must be converted into logarithms with positive (17) In similar manner, the values of K, K' ', and K" for Equations i, 2, 3, 4, 5, 6, 7, 13, 16, 17, 18, and 22 in Table II have been calculated. In those reactions involving CO and CO 2 , as 19, 23, and 26, use has been made of the approximation formulas for the same as worked out by Mayer and co-workers, 1 but substituting the values of q shown in the table. CALCULATION OF HEATS OF REACTIONS FOR DIFFERENT EQUILIBRIA The heat absorbed or emitted in a given reaction was determined by means of the ordinary thermochem- ical methods of addition and subtraction, as in the following typical examples: (a) 2C + 8H = 2CH + 37800 cal. 2C + 4H = CgH4 14600 cal. 2CHU = C 2 H 4 + 2H 2 52400 cal. (6) 6C + 6H = 3C 2 H 2 174300 cal. 6C + 6H = CH 11300 cal. 3C Z H 2 = C 6 H 6 + 163000 cal. (c) C + 2H 2 = CH 4 + 18900 cal. 2H + O = HiO + 58300 cal. CH4 + H 2 O = 3H 2 + C + O 77200 cal. C + O = CO + 29000 cal. _ CH 4 + H 2 = 3H + CO 48200 cal. It is likewise possible to combine the values of K for one reaction with K' for a second reaction in order to determine K" for the resultant reaction. C + 2 H 2 = CH 4 K = P Hi 2C + H 2 = C 2 H 2 K' = Put Dividing the square of the methane equilibrium by the acetylene equilibrium, one gets = This operation can be represented by the equation 2 CH 4 = C 2 H 2 + 3 H 2 In this work the values of K and K' have been com- bined in the manner just shown in order to determine values for equations 8, 9, 10, n, 12, 14 and 15. The Nernst approximation formula could be applied di- rectly to each of these equations with the same results. All reactions indicated in Table II may go in either direction. Attention is called again to the fact that the reactions given must be used with a consideration of all factors involved; no equation by itself repre- 1 Mayer, Henseling and Altmayer. Jour.Gasb., 1909, pp. 166, 194, 238. (18) sents a complete system. All the gases mentioned, together with many others, are tending to reach equilibrium with one another. Tar compounds were not listed. Benzene, C 6 H 6 , has been used as typical of all tar formations. In technical practice one gets benzene and other tar compounds from methane hydrocarbons; from experimental evidence, it is known that from ethylene 1 or acetylene 2 the same re- sults are reached. Throughout the literature one finds questions as to whether methane goes to acetylene, or acetylene to methane, ethane to ethylene, ethylene to ethane, etc. Considered in the light of this study it appears that regardless of which hydrocarbon is used initially there is a pronounced tendency for the system to reach a common equilibrium dependent upon the existing temperature. With hydrocarbons the result seems to depend more upon conditions of temper- ature, pressure and concentration than upon the initial hydrocarbons. In other words, with proper condi- tions of temperature, pressure and concentration, and with sufficient time for complete reaction, the final equilibrium will be that of the mentioned hydrocarbons and their reaction products, regardless of whether decane, hexane, ethane, methane, ethylene or acetylene, a singly or in mixtures, are used in the beginning. Table II furnishes the basis for the experimental work of this research. Its interpretation serves as a guide in determining the direction of experiments.. Taking Equation 9 as typical, where K 600 = o.ooooooi and Kgoo = 0.0004, it seems advisable to exceed 900 C. in temperature. However, referring to KWO = 0.077 an d K 9 QQ = 0.003 f r Equation 3, it is evident that the rate at which methane would de- compose to carbon and hydrogen, in accordance with Equation 3, easily might be sufficient to offset all C 2 H 4 formation, in accordance with Equation 9. Considering Equations 16 and 19, two of the most vital in present carbureted water gas manufacture, one finds Ksoo KTSO Kso9 16 C + H 2 "^Z. CO + Hj 0.2 3.1 25.0 19 rw. + w.n ^ rr> -i STT. o.06 8.7 346.0 1 Ipatiew, Ber., 1911, p. 2978; Ipatiewand Rontala, Ibid., 1913, p. 1748. 2 R. Meyer ./&<*., 1912, p. 1609; Meyer and Tanzen, Ibid., 1913, p. 3183. W. A. Bone. Jour. f. Gasb., 1908, p. 803; D. T. Day, Am. Chem. Jour., 1886, p. 153; V. Lewes, Proc. Roy. Soc., 1894, p. 90; Worstall and Burwell, Am. Chem. Jour., 1897, p. 815; Bone and Coward, Jour. Chem. Soc., 1908, p. 1197; Sabatier and Senderens, Compt. rend., 130, 1559; C. Paal, Chem. Ztg.. 1912, p. 60; Ipatiew, Ber., 44, 2987. (19) o M X tN X 5 r>. O ""* lit s d o 5 X & 8 *" 3 <" 35 B .2 sk O O o So u o H WW rtfNrt __^ & 3z -+J+J o^o I >3 2^8888 ooooooc| c 6 ^ I s ss ? s r^ oo ^1 ro CM O i 2 < x r >. 8. - 8 : : *! 1 ; C s o o o - d ! - c 5 C 5 ; ^ ei g slOgjgSgcffl&gjI B B - 6 ^ ., ~ x x X X X X i X v O hH B ^ ^ X V^:XX 8lw xx x x CJ X qX fflX X x gg ! js^LggiLji 8 8 cjEcj^ycj^lcj^Jcjcj 5*3 gllll II II II II II II " " 1 1 II 1 II 1 v;>^V^!^lxi>l> < fc tj {^ ' d u 000000000005 SO 10 o o 8 o CM o^ O\ *5 + T 1 B e CM K B fD + B + CJ 6 CJ CJ n . o B q N w + ^_ CJ o O 8 1 \f\ 164500 r^ ro CM o CM 8 8 8 CM T \ 1 T + + 1 ' ' B B B B B VO B >o B B CM j I i * -|- -f- CM 1 U CM 8 6 u O O CM 8 o 8 n n n H 11 ll CM n n n q o q O q q i * 6 Q B B ffi m B B n 6 CJ CJ CM CM CM * + u CN + i i i B o B CJ CeH 6 . ' Journal f. Gasb., 1910, 53. 2 Journal of Gas Lighting, 1906, 825. 3 Jour. Soc. Chem. Ind., 1892, 584. 4 Rogers' "industrial Chemistry." * Lewes, Proceedings of Royal Soc., 1894, 90; W. A. Bone, Jour. f. Gasb., 1908, 803; Bone and Coward, Jour. Chem. Soc., 1908, 1 197. (30) 2001 . I too i" HXH 80 60 40 20 10 Gas 10 20 PrM$ure 30 Carbon 20 30 40 Pres. Tar 10 20 30 40 Pres CH 4 10 20 30 750C. 40 Pres FIG. V VARIATIONS IN YIELDS OP PRODUCTS AT 750 C., UNDER VARYING PRESSURES. (TABLES II, III, IV AND VI) (31) 40 20 III. 10 20 30 40 Prcs. III. 10 20 30 40 Prts 20 30 40 C 2 H 6 10 20 30 40 Pre 750 C. vi VARIATIONS IN YIELDS OP PRODUCTS AT 750 C., UNDER VARYING PRESSURES. (TABLES II, III. IV AND VI) (32) On the other hand, it seems reasonable to expect that, under a high pressure, it will be considerably more difficult for one volume of oil vapor to break up or expand to many volumes of gas than under reduced pressure. In the system OIL T^ GAS "^1 TAR (Few volumes) (Many volumes) (Few volumes) one would expect that the application of high pres- sures would increase the difficulty of generating gas, and after the gas is generated it would make easier the condensation reactions which proceed to the tar stage. Since the unsaturated hydrocarbons, ethylene and acetylene, polymerize most readily, increased pressure should preferably condense them with the formation of tar compounds. In addition to the direct influence of pressure, it may be assumed that when working under increased pressure the gaseous hydro- carbons are subjected to the influence of heat for a longer time, which further tends towards the forma- tion of heavy condensation products at the expense of the illuminants. The following series of experi- mental results appears to justify these conclusions: TABLE III Oil used, 400 cc. Pressure Temp. Absolute Gas Carbon Tar C. Lbs. Liters Grams Cc. 650 45 145 8 133 750 45 194 26 87 900 45 310 165 9 Analysis of Gas from Table III Temp. CtH 6 CH 4 H 2 111 C. Per cent Per cent Per cent Per cent 650 11.5 45.1 9.3 30.5 750 6.1 56.6 17.5 15.5 900 None 41.6 50.0 5.0 The yields of gaseous hydrocarbons are lower than those shown in Table II, which were obtained at the same temperatures, and likewise the maximum yield is lower than the maximum obtained under atmospheric pressure. EFFECT OF DIMINISHED PRESSURE ON GASEOUS REAC- TIONS By referring to the OIL-GAS-TAR system cited above, it becomes evident that a high vacuum would favor the increase in volume due to cracking the oil into gas and at the same time withdraw the gas from (33) 200 100- 150- 125 100 75 50 25 10 10 Gas 10 20 30 40 Pressure Ibs./sq.in. Carbon 20 30 Tar 20 30 CH 4 900C. 30 40 Pres. 40 Prcs. 40 Pres. FIG. VII VARIATIONS IN YIELDS of PRODUCTS AT 900 C., UNDER VARY- ING PRESSURES. (TABLES II, III, IV AND VI) (34) 100 50 10 10 10 10 20 30 Ill 20 30 H 20 30 20 30 yooc. 40 Pres. 40 Pres. 40 Pres. 40 Pres. FIG. VIII VARIATIONS IN YIELDS OF PRODUCTS AT 900 C., UNDER VARY- ING PRESSURES. (TABLES II, III, IV AND VI) (35) the heat zone before it could form tar. The effects of this reduced pressure can best be observed from the results of the following experiments: TABLE IV Oil used, 400 cc. Temp. Pressure Gas Carbon "Tar" C. Absolute Liters Grams Cc. 750 1/20 to 1/30 atmos. 146 1 153 850 1/20 to 1/30 atr nos. 211 3 100 900 1/20 to 1/30 atr nos. 234 3 60 950 1/20 to 1/30 atr nos. 235 12 58 Analysis of Gas from Table IV Temp. C 2 H 6 CH 4 H 2 111 C. Per cent Per cent Per cent Per cent 750 . . . 12.5 56.1 850 3.4 20.5 15.6 52.9 900 1.3 24.0 17.3 52.1 950 Trace 27.0 20.8 46.9 This striking difference in end products due to di- minished pressure seems to have been overlooked, perhaps because for the first few pounds per square inch vacuum the increase is not marked. INFLUENCE OF CONCENTRATION CHANGES ON GASEOUS REACTIONS The present investigation has merely opened this field. It has been established that oil cracked in an atmosphere of a gas, such as hydrogen, which reacts chemicalry with the end products of the cracking process, will yield products which are not analogous to those resulting from a physical mixture of the two gases. Not only does the mere presence of the ad- mixed gas influence the end products, but as is to be expected from the theoretical consideration, the quan- tity of the admixed gas is influential. To study the various gases and their quantitative relation will require much further experimental work. The results of preliminary study indicate that there is a vital relationship between the resulting gases in a crack- ing process and the atmosphere in which the oil is cracked. This relationship is likely to be of commer- cial significance in practical water gas carburization. The quantity of CO and H 2 admixed per gallon of oil cracked is an important factor, just as the tempera- ture and the pressure have been shown to be impor- tant factors. Jones, 1 in his improved all oil water gas process, recognizes the importance of adding an 11 active gas" to the cracking zone, but considers 1 The Gas Age, 1913, p. 369; American Gas Light Journal, 1913, p. 272; Gas World, 1913, 916. (36) 650* 50* 750* 45*/ n "Pres.- Abs. Temperature in Degrees C. ATmos. Pres. 750* 80' Vacuum T. ILLUMINANTS FIG. IX PERCENTAGES OF ILLUMINANTS UNDER VARYING TEMPERATURES AND PRESSURES. COMPILED FROM TABLES II, III AND IV (37) 30- 20- Abs, 650' 750* 850 20- Atmos. PPCS. 650 750 850* 900 2 2 120 100 80 60 Vacuum 750* 850" T. ILLUMINANTS FIG. X LITERS OF ILLUMINANTS UNDER VARYING TEMPERATURES AND PRESSURES. COMPILED FROM TABLE VI (38) the effect of the presence of the admixed gas to be catalytic. Hempel 1 found that by cracking oil in the presence of hydrogen not only did none of the hydro- gen split off from the hydrocarbons, but part of the admixed hydrogen actually combined for the formation and preservation of hydrocarbons. On the other hand, on the basis of a single experiment reported, he maintains that the presence of CO in the cracking zone is similar to the presence of a neutral gas and is without material influence on the end products ob- tained from the oil. As to the hydrogen, the results of this research agree with the observations of both Hempel and Jones. The quantity and quality of gas per cc. of oil increase, and qualitative results show that the tar and deposited carbon decrease. TABLE V Pressure Hz Liters Shrinkage Temp. Absolute admixed. ' * ^ in Hz. C. Lbs. L. C 2 H 6 CH< 111 H 2 Liters 750 15.0 358 15.4 125.0 70.6 308 50 800 15.0 412 18.0 116.0 83.2 335 77 750 0.75 400 9.5 52.0 112.0 381 19 810 0.75 413 86.5 140.0 378 35 860 0.75 388 99.5 133.0 350 38 900 0.75 292 92.0 120.0 272 20 960 0.75 382 95.0 113.0 348 34 From these results it appears that a greater per- centage of the admixed hydrogen enters into combina- tion to form saturated hydrocarbons when the crack- ing process is carried out under atmospheric pressure, than is the case under greatly reduced pressure. The percentage increase in yield of the illuminants when the cracking process is carried out under reduced pressure in the presence of hydrogen is about as great, however, as is the percentage increase in illuminants when the reaction is carried out under atmospheric pressure. INFLUENCE OF TEMPERATURE, PRESSURE AND CONCEN- TRATION CHANGES ON COMPOSITION OF RE- SULTANT TARS If changing temperature and pressure have a marked influence on the quantity and quality of gaseous hydro- carbons obtained from cracking petroleum oil, one should expect simultaneous changes in the condensa- ble hydrocarbons, which differ from the permanent gaseous hydrocarbons only in that they are liquid or solid at ordinary temperatures. There should be equi- librium between all hydrocarbons of a series at the i Jour. f. Gasb., 1910, p. 53, et al. (39) high temperatures prevailing in the furnace where practically all the hydrocarbons are gaseous. That the end products should contain ethylene and then suddenly jump to hexene is not to be expected, any more than that the hydrocarbons in coal tar would jump from benzene to naphthalene or anthracene. In industrial practice the "illuminants" are usually said to consist of 75 per cent ethylene and 25 per cent benzene vapor. When the gas made by cracking oil in the apparatus under one-thirtieth of an atmosphere pressure abso- lute is passed over palladium in the presence of an excess of hydrogen, over 90 per cent of the illuminants are converted into saturated hydrocarbons, prin- cipally ethane, indicating that the illuminants con- tain but little, if any, benzene vapor. If the gas con- tains no benzene, it is only logical to believe that the condensable hydrocarbons contain no aromatic hydro- carbons. It is .further found that the vacuum tar will combine with 1.82 sp. gr. sulfuric acid. It has a low specific gravity, and on permitting the higher boiling point fractions to stand, no naphthalene or anthracene separate out. Tars resulting from crack- ing oil in carbureting blue water gas under atmos- pheric pressure contain quantities of benzene, toluene and other aromatic hydrocarbons in sufficient amounts to be of commercial importance. In view of these facts, there is justification for the statement that tars which result from cracking petroleum under low pressures are different from those which result from cracking under atmospheric or higher pressure. Instead of benzene, toluene and other aromatic hydro- carbons, the vacuum tar contains members of the more unsaturated hydrocarbon series. The composition of these tars is now the subject of a further investiga- tion. SUMMARY In the theoretical discussion on the influence of dimin- ished pressure on oil gas manufacture, it was pointed out that one should expect an increase in the yield of gaseous hydrocarbons from a given amount of oil by reducing the pressure below atmospheric. This increase should reach a maximum as the absolute zero of pressure is approached. The correctness of this is shown by resultsrecordedin Tables IV and VI. Not only are the gaseous hydrocarbons yields greatly increased, but the deposited carbon is practically eliminated, (40) and there is much less gaseous hydrogen produced than in the product obtained at the same tempera- tures under higher pressure. It was pointed out that increasing the total pressure under which the oil is cracked to several atmospheres will decrease the gaseous hydrocarbon yields from a given amount of oil. Experimental results, shown in Table III, have proven this correct. It was pointed out that varying the pressure on the system would enable one to better control the quan- tity .and quality of "tar" obtained than at present where all tar is made under atmospheric pressure. Experimental results indicate considerable flexibility. It has further been established that the end prod- ucts resulting from cracking oil in an atmosphere of a gas, such as H 2 , which reacts chemically with the end products of the cracking, are a function of both the composition and the quantity of the gas admixed, per Table V. Experiments, Table IV, have proven that it is possi- ble to "crack" oil at a temperature of 900 C. with- out depositing more carbon than i% by weight of the oil used. TABLE VI SUMMARY OF GAS TABLES (All based on 400 cc. oil and calculated to C., and 760 mm. pressure) Pressure Temp. Lbs. per Gas Carbon Tar C2H 6 CH< H 2 111 C. sq. in L. G. Cc. L. L. L. L. Atmospheric Pressure Group (See Table II) 650 15.0 135 3 163 13.8 45.5 12.1 58.8 750 15.0 206 18 80 10.15 84.5 39.6 63.0 900 15.0 382 115 11 Trace 178.1 148.2 50.0 High Pressure Group (See Table III) 650 45.0 145 8 133 16.7 65.2 13.1 44.3 750 45.0 194 26 87 11.8 110.0 33.9 30.1 900 45.0 310 165 9 None 128.9 155.0 15.5 Low Pressure Group (See Tables I and IV) 750 0.75 146 1 153 .. .. 18.3 82.0 850 0.75 211 3 100 7.16 43.2 32.9 111.5 900 0.75 234 3 60 3.0 56.0 40.0 122.0 950 0.75 235 12 58 Trace 63.4 48.8 110.0 Admixed Gas Group (See Table V) Hydrogen admixed L. 750 15.0 358 Hydrogen shrinkage L. 50 15.4 125.0 308.0 70.6 800 15.0 412 77 18.0 116.0 335.0 83.2 750 .0 400 19 9.5 52.0 381.0 112.0 810 .0 413 35 86.5 378.0 140.0 860 .0 388 38 99.5 350.0 133.0 900 .0 292 20 92.0 272.0 120.0 950 .0 382 34 95.0 348 . 113.0 (41) Through a proper consideration of equilibrium and mass action conditions under various degrees of tem- perature and pressure, much can be expected in gaseous reactions. It soon becomes evident that the single stage method wherein endothermic and exothermic, expansion and contraction reactions are combined in a single apparatus, is open to question. (42) VITA Walter Frank Rittman was born in Sandusky, Ohio, on December 2, 1883. Before entering col- lege he spent four years in the shops and drawing rooms of steel and machine manufacturers in Cleveland, Ohio. He received the degrees of A.B. from Swarth- more College in 1908, M.A. in 1909, and M.E. in 1911. During 1909 he served as chemist in the lab- oratory of the United Gas Improvement Company, of Philadelphia. From 1909 to 1912 he was engaged in professional chemical engineering work in and about Philadelphia, and at the same time held the position of lecturer and laboratory instructor in Industrial Chemistry at Swarthmore College. From 1912 to 1914 he was engaged in graduate study in Columbia University. He was special lecturer on Industrial Chemistry at Columbia University in the Summer School of 1913. UNIVERSITY OP CALIFORNIA LIBRARY THIS BOOK IS DUE ON THE LAST DATE STAMPED BELOW 19)6 46 30m-l,'15 UNIVERSITY OF CALIFORNIA LIBRARY