October, 1927
ILVDUSTRIAL A N D ENGINEERISG CHEMISTRY
ticularly adaptable for casting because they have a slight tendency to expand in the molds during setting, thereby accurately reproducing even the finest lines of the mold. A very fire-resistant paint to be applied over wood surfaces
1143
may be made with oxychloride cement as the binder. Closely allied to such a paint in composition is the “Plastic Mosaic” used by Paul Honor6 in the mural painting in the court room of the Midland County Courthouse. (Figure 1)
Absorption of Nitrogen Oxides in an Aqueous Suspension of Phosphate Rock’” By V. N. Morris FIXEDh-ITROGEN RESEARCHLABORATORY, BUREAUOF CHEMISTRY
AND SOILS, W A S H I N G T O N ,
D.
c.
A comparison has been made of the absorption of O S C U R R E S T L Y with involves the formation of calnitrogen oxides with and without phosphate rock the d e v e 1o p m e n t of cium sulfate, which generally present, not only with water as the original absorbent, the ammonia synthesis remains as a diluerit of the but with various solutions of nitric acid as well. This resulting product. With hyindustry it is essential that procedure seemed desirable since in the ordinary there be developed a diversifidrochloric acid d i c a l c i u m method of absorbing nitrogen oxides the concentration cation in products providing phosphate can be obtained.6 of nitric acid in the absorbing medium becomes prothe various forms of nitrogen I t appears entirely logical to gressively greater as the absorption proceeds and prodemanded by the fertilizer apply nitric acid to this use, gressively reduces the rate of absorption. industry and a larger number effecting in one operation the After it had been established that the addition of the of channels through which the neutralization of that acid proper quantity of finely ground phosphate rock tends products can reach their logand the liberation of monoto increase the absorption, the investigation was exical market. Although amc a l c i u m phosphate. The tended to include a study of the absorption in solumonium sulfate constitutes direct absorption of nitrogen tions of the various individual components which might one of the most popular and o x i d e s in phosphate rock, be expected to be present in the mixture resulting from u s e f u l ammoniates now in eliminating the intermediate the action of nitric acid on phosphate rock. As a final use in the American fertilizer formation of concentrated, step undertaken to gain information about the possible industry, liberal supplies are aqueous nitric acid, appears applicability of a countercurrent system, the degree already available from exista desirable simplification of of absorption and the solvent action on the rock in a ing sources. It is desirable this proposal. Some results three-tower system were determined. t h a t p r o d u c t s yielded by obtained in a study of the t h e ammonia synthesis inreactions involved are predustry be complementary rather than competitive. Ameri- sented in this preliminary paper. can production of nitrates is still small and our dependMaterials ence on foreign sources continues unmodified, although nitrates still enjoy unimpaired popularity among fert,ilizer The phosphate rock was Florida pebble rock ground to compounds and in many applications are regarded as necpass a 100-mesh screen completely and a 200-mesh screen essary. Although the technology of the oxidation of ammonia t o nitric acid is well u n d e r ~ t o o d ,considerations ~ involving to the extent of about 70 per cent. Different samples varied national defense demand increased peace-time production slightly in composition, the average PZOScontent being about of t,his war-time essential. Desirable diversification in 32.5 per cent. Both liquid nitrogen tetroxide and gaseous nitric oxide products is obtainable t’hroughthe manufact’ureof ammonium served as original sources of the nitrogen oxides. The former chloride, sulfate, and phosphate and urea, and the oxidation of a portion of t,he ammonia synthesized to form ammonium, was prepared by the catalytic oxidation of ammonia, and the latter by the interaction of sulfuric acid and sodium calcium, potassium, and sodium nitrate^.^,^ Pending the further cheapening of pyrolytic methods nitrite.’ The average purity of the nitric oxide as indicated of producing phosphoric acid, the acceptable method of by the ferrous chloride method* was 97.5 per cent. ,Is rendering available the phosphoric acid of phosphate rock time was available for a nearly complete oxidation of the will doubtless continue to depend on acid treatments. Sul- nitric oxide when this gas was used, the gaseous mixture furic acid is the reagent commonly employed, but its use entering the absorption vessel consisted largely of Kz04, NO*,X2, and 02, regardless of the original source of the Received March 16, 1927. Presented before t h e Division of I n nitrogen compounds. dustrial and Engineering Chemistry a t t h e 73rd Meeting of t h e American
C
Chemical Society, Richmond, Va., April 11 t o 16, 1927. The h-orwegians had in operation a t one time a process, patented by Bretteville (German Patent 217,309), for t h e production of a fertilizer mixture containing “nitrate” nitrogen a n d soluble phosphate, in which crude phosphorite was decomposed by 60 per cent nitric acid. Peacock [U. S P a t e n t 1,057,876 (191311 has proposed t h e direct production of calcium nitrate a n d water-insoluble dicalcium phosphate by exposing a thin paste consisting of ground phosphate rock and wdter t o t h e nitrous gases from an electric arc-a suggested reaction which we have not been able t o verify. A recent patent granted t o Italian interests [Toniolo, British Patent 247,230 (1925); Chem. Age ( L o n d o n ) , 14, 386 (1926)l covers a process f o r absorbing nitrogen oxides in a suspension of insoluble calcium phosphate. 3 Parsons. THISJ O U R N A L , 19, 789 (1927). Ross, Mehring, find -Merz, I b i d . , 19, 211 (1927). 5 Morris, I b i d . , 19, 912 (1927).
Experimental Method and Apparatus
The apparatui was modified several times during the various experiments. Figure 1 shows the arrangement when the source of the nitrogen oxides was liquid SzO1 and the absorption system corisisted of three vessels in series. With flowmeter B calibrated to deliver a definite flow of air, another stream of air was passed through flowmeter B‘, the cooling coil C, arid then saturated with S201a t 0 ” C. 6
F o x and Whittaker, T H I SJOIJRNAI., 19, 349 (1927) Chem Soc , 47, 2170 (1925). Morris, I b r d , 49, 979 (1927).
’ Noyes, J . .4m 8
INDUSTRIAL A N D ESGISEERISG CHEMISTRY
1144
by passage through saturator D. By analyzing the exit mixture while the reading of flowmeter B was constant, flowmeter B' was calibrated in terms of the percentage of K204in the resulting mixture. When gaseous nitric oxide was used as a source, the K \ T ~saturator O~ was omitted and three baffled mixing chambers replaced the one shown a t E. The absorbing medium was placed in F-F'-F", the exclusion of air from which was insured by means of ground-glass connections and mercury seals a t H-€€'-Hi'. The absorption vessels had a capacity of approximately 450 cc. each. For some of the experiments a single, larger absorption vessel replaced the three shown. The stirrers were operated by small electric motors. G served as a sampling tube preparatory,to analysis.
Figure 1-Apparatus
P I
100 1OO-P*
in which z is the fraction absorbed and PI and P2 are, respectively, the original and final percentages by weight of nitrogen oxides in the mixtures. This equation takes account of the reduction in volume resulting directly froin absorption but not of the smaller reduction resulting from the re-oxidation of the nitric oxide liberated after absorption. Absorption in Water and Nitric Acid with and without Rock Present
I n this set of experiments nitric oxide n a s used as the original source of the oxides. The absorption took place in a single spherical ressel haring a capacity of approximately 1 liter. As the absorption vessel was not in a thermostat, the results were rejected whenever the room temperature varied by more than l o from 23" C. The total velocity of the incoming gases was 100 cc. per minute. Analyses 9
THISJOWRNAL, 11, 745 (1919).
of the incoming gases, made after time had been allowed for practically complete oxidation of nitric oxide to dioxide, indicated the average percentage by weight of the latter to be 10.09. The rheostat controlling the velocity of t h e stirrer was always set a t the same place. Owing to belt slippage and other causes, the actual velocity of the stirrer mas not exactly constant. The average value was about 820 r. p. m. KO thermometer was kept in the absorbing medium. Its approximate temperature was followed by means of a thermometer held against the bottom of t h e vessel and insulated from the air by a packing of asbestos. It was planned to compare the completeness of absorption in 100-cc. samples of absorbing media consisting originally of water, 20 per cent nitric acid, 40 per cent acid, and-60
for the Absorption of Nitrogen Oxides
The usual method of following the course of an absorption experiment consisted in analyzing the gases leaving the absorption vessels. The determination of the nitrogen oxides in the effluent gases obtained when phosphate rock was absent was made by a method essentially the same as that of Gaillardg-i. e., absorption in excess sodium hydroxide and back titration with acid. I n the presence of phosphate rock other gases of acid nature are evolred, so that direct titration is not dependable. The most satisfactory of the several methods tried in this case seemed to be determination of total nitrogen after reduction n-ith Devarda's alloy. One determination of the compoqition of the incoming gas was sufficient for any gix-en comparison. since the flowmeter readings were kept constant. The equation used in calculating the percentage absorption of nitrogen oxides took the form of x = - P1-P* .-
Vol. 19, No. 10
per cent acid with the absorption in the same volume of similar solutions to which had been added 10, 100, 200, and 300 grams of phosphate rock, respectively. These quantities of rock were considerably in excess of those necessary to react with the acid present. Since the other runs had demonstrated that too much rock was detrimentar to the absorption, only 75 grams of rock were added to t h e GO per cent acid. Several factors contributed to render the first few determinations of each run unreliable. The addition of the phosphate to the acid caused a rise in temperature which amounted to 25" or 30" C. in extreme cases. It was generally 3 hours or more in such cases before the temperature of the absorption vessel was again about the same as that of the room. It \vas also found to require considerable time to sweep the apparatus free from the gases remaining from the previous run (or the air which had been allowed to enter). I n the extreme case of the 60 per cent acid this sweeping process had probably not been completed a t the end of the run. Although analyses were made hourly from the beginning of the run, results are shown for single analyses only obtained a t the end of a run of several hours, after which time a steady state had been reached. Attention should be directed to the fact that a t the time of the analyses shown the acid concentrations were not the same as those of the original media, since sufficient nitric acid to increase the concentration several per cent had been formed from t h e oxides absorbed. Table I-Comparison of Absorption of Nitrogen Oxides in Various Nitric Acid Solutions with and without Phosphate Rock Present
ORIGINAL ABSORBING MEDIA IVater alone Water t rock Z O r 0 acid alone 2Oy0 acid rock
+
A-nOa E S C - ~ P I N G ABSORPTION AFTER 5 HOURS
Pev cent 11.42
11.15 17.34 15.01
ORIGINAL S 2 0 4 ESCAPING ABSORBING ABSORPTION AFTER L M ~ ~ 7 HOURS ~ ~ 40% acid alone 40% acid rock 60% acid alone 60Yc acid rock
+
+
Per cent 24.18 31.32 99.90 77.14
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I,VDUSTRIAL A S D ENGINEERISG CHEMISTRY
October, 1927
Although the addition of 75 grams of rock to the 60 per cent acid had a decidedly beneficial effect on the absorption, the same was not true for the addition of 200 grams to the 40 per cent acid. The proportion of rock in the second case was so great that a very thick paste formed when the mixture was allowed to stand overnight. It is apparent that sufficient rock to interfere with absorption can easily be added. I n the case of the 20 per cent acid the 100 grams of rock added was not such a large amount but that an improvement in the absorption occurred. Better results with both 40 per cent and 20 per cent acids would probably have been obtained had less rock been used. Effect of Varying Quantity of Rock Added
The next set of experiments involved an attempt t o demonstrate that the absorption could be improved by the addition of the proper amount of rock to a 40 per cent acid solution. The conditions were the same as in the previous experiments. The results (expressed in terms of the completeness of absorption) are shown for several successive hourly analyses in Table 11. As anticipated, the percentage absorption was found t o decrease in general with the length of the run. The results tended to prove what had been surmisedi. e., that the addition of a suitable quantity of phosphate rock would improve the absorption of nitrogen oxides. Although the addition of 200 grams of rock was quite detrimental, and of 100 grams was slightly so, the percentage absorption was increased by the addition of 50 grams of rock to 100 cc. of the acid. Table 11-Effect o n Absorption of Nitrogen Oxides of Varying Amount of Phosphate Rock Added t o 40 Per Cent Solution of Nitric Acid DURATION 100 cc. ACID 100 cc. ACID 100 cc ACID OB R U N 100 cc. ACID 50 G . R O C K 100 G . R O C K 200 G. R O C K Hours P e r crnl P e r cent Peu cent P e r cent
+
+
+
after a considekable quantity of nitrogen oxides has been absorbed. Table 111-Absorption of Nitrogen Oxides i n a Three-Vessel System with a n d without Phosphate Rock Present DURATION O F RUN WATER WATER ROCK HGWS Per cenl P e r cent 1 95 9 95 8 3 94 8 94 8 94 3 5 7 94 4 93 6 93 5 92 5 91.8 ii 92.4 13 92.5 90.3 15 91.7 88.6 li 88.3 19 90.9 86.4 21 90.6 84.2 23 90.7 25 89.4 27
+
Absorption in Solutions of Calcium Nitrate, of Monocalcium Phosphate, and of Phosphoric Acid
The previous results having demonstrated that the addition of phosphate rock in the proper proportions will lead t o improved absorption of nitrogen oxides, it seemed worth while t o attempt to get a better insight into the reason fop this improvement. It can be accounted for if the absorption in a solution of calcium nitrate or phosphoric acid or monocalcium phosphate (the substances presumably present in the largest quantities) is more complete than in a solution. containing an equivalent quantity of nitric acid. A series of experiments was therefore undertaken with the object of establishing how calcium nitrate alone, monocalciurn phosphate alone, phosphoric acid alone, and nitric acid alone affect the absorption of the oxides of nitrogen in tho presence of excess oxygen. The apparatus used and the conditions maintained XTere the same as in the case of the experiments reported in Table I. sz
Absorption in a Three-Vessel System with and without Phosphate Rock Present
A complete absorption run in a three-vessel apparatus seemed desirable. as such a system more closely approxiniates the tower system a-hich would probably be used on a commercial scale. In this comparison each ressel contained 100 cc. of water as the original absorbing medium in one case and 100 cc. of water to which had bpen added 75 grams of rock in the other case. Thebe runs were of much longer duration than those previously described. The incoming gas was also richer in S?Od. containing 15.97 per cent of this gas by weight. This value corresponds approximately to 10.7 per cent of non-polymerized SO2 by volume. The total rate of flow of the gases was about 315 cc. per miiiut e-considerably faster than in the previous work. An attempt was made t o keep all the stirrers revoking a t about 450 r. p. m. The temperature of the water bath was 20" C. A device was set up to avoid the difficulty resulting from the alteration in the flowmeter readings as the viscosities and volumes of the solutions changed. A bypass, having a resistance approximately the same as the greatest resistance developed during the experimental run was attached a t J (Figure 1). During calibratlon of the flowmeters the gas passed through this bypass. During the absorption run the stopcocks a t G were partially closed, so that the total resistance of the absorption system just balanced that of the by-pass. The results (Table 111) bring out more clearly that which was indicated by the results sho7T-n in Table I-i. e., that, although the presence of phosphate rock contributes little if anything to the absorption at first, it is quite beneficial
I
I
1
I \
1146
INDUSTRIAL A N D ENGINEERING CHEMISTRY
ie equivalent to 12.6 and 9.4 per cent solutions of the respective salts. The curves shown with dotted lines in Figure 2 are obtained by plotting with the same abscissa the absorptions of solutions equivalent to the nitric acid solutions rather than those of the same concentration as the nitric acid solutions. The results obtained verified the assumption that replacement of nitric acid by either of the two salts is adrantageous from the standpoint of the absorption of nitrogen oxides. An additional but rather incomplete series of experiments tended to demonstrate that solutions of phosphoric acid, although not so satisfactory as those of the two calcium salts, are better absorbing media than solutions of nitric acid. A study of the curves shown in Figure 2 indicates that the addition of monocalcium phosphate up to the extent of about 14 per cent or calcium nitrate t o the extent of about 21 per cent leads t o an actual improvement in the absorption of nitrogen o x i d e in water. The degree of absorption goes up slightly to a maximum with low concentrations of these silts, and then steadily decreases. h certain decrease was expbcted, since the actual quantities of water available for absorption were Iess with the more concentrated solutions. An adequate explanation of this tendency to pass through a maximum has not yet been developed. There appears to Be no parallelism between the absorption of nitrogen oxides
I
Duration af Ran h Hour8
and any such properties as surface tension, hydrate formation, or internal pressure. Although the presence of the calcium salts might be expected, by altering the ionic strength, to influence the activity of the nitric acid formed during absorption,’O the manner in which this might increase the degree of absorption is not apparent. If there were a tendency towards complex formation between the salts and nitric acid an increased absorption would be probable. Experimental evidence for this supposition is lacking.” I n the case of the monocalcium phosphate one probable factor is the reaction between the salt and nitric acid formed. If it could be established that the presence of the calcium salts shifts the water equilibrium12 in the direction of that form of water in which nitrogen oxides are more soluble, 10
Lewis and Randall, “Thermodynamics,” p. 364-85, McGraw-Hill
Book Co., 1923. 11 18
Bassett and Taylor, J Chem. SOC.(London), 101, 581 (1912). Baacroft, J . Phys. Chem., 30, 1194 (1926).
Vol. 19, No. 10
the results would be more understandable. If, as another possibility, it could be demonstrated that the calcium salts act as catalysts either for the decomposition of nitrous acid, which is probably one of the primary products resulting from absorption, or for the re-oxidation of the nitric oxide liberated subsequent to absorption, an explanation would be more apparent. It is hoped to give this matter a more thorough study a t a later date, Solvent Action on the Phosphate Rock
The first of these experiments consisted of a run of 15 hours’ duration in which a gaseous mixture containing 6.56 per cent of nitrogen tetroxide by weight was passed into a suspension of 10 grams of rock in 250 cc. of water contained in a single absorption vessel. Except for the fact that the total rate of flow of the gases was 200 cc. per minute, the conditions were the same as those of the experiments reported in Table I. At the end of each 3 hours the stirrer was stopped, the gases shut off, and the solid material in the suspension allowed to settle. Samples of the supernatant liquid were than removed and analyzed for soluble phosphate. The results are shown in Figure 3. Calculations made by a method similar to that used by Fox and Whittaker6 indicate that even before the run was half completed there had been introduced sufficient nitrogen oxides to react with all the compounds in the rock and to convert all the phosphate into the monocalcium salt. From the results obtained, it is apparent that under the conditions of this experiment either an appreciable excess of acid or a considerable time interval is required to complete the process of solution. I n the final experiment an attempt was made to simulate the conditions that might be encountered if a countercurrent system were employed. The three-vessel apparatus shown in Figure 1 was used. As in the case of the experiments reported in Table 111, each vessel contained 100 cc. of water and 75 grams of rock, and the gases, containing 15.97 per cent by weight of nitrogen tetroxide, entered a t a rate of 345 cc. per minute. At the end of 13 hours the run was stopped, 100 cc. of water was added to each vessel, and the mixtures were thoroughly agitated to insure that all of the water-soluble phosphate was in solution. After filtration the solutions were analyzed for CaO, P.205, and total nitrogen. By stopping the run a t the end of 13 hours it was certain that the nitric acid was insufficient to react with all the rock in the first vessel. Under these circumstances, the distribution of CaO, P20r, and total nitrogen between the three vessels should be somewhat similar to the distribution to be expected in a three-tower absorption system operated on a larger scale. The results are shown in Table IV. Table IV-CaO,
P z 0 5 ,and Total Nitrogen i n Solution after 13 Hours’ Absorption in a Three-Vessel System PERCENTOF TOTAL IN GRAMS IN EACH VESSEL EACHVESSEL RATIO VESSEL CaO P201 Nz CaO PzO6 NP Ca0:PzOr 79.6 1.52:l 78.9 81.5 17.2 11.7 1 26.2 1.71:l 14.7 15.0 2.2 16.0 2 5.3 3.1 5.4 2.13:l 3.8 0.8 5.1 3 1.7 0.8
As is indicated in Table IV, the average distribution ratio of each of the three substances is 80 in the first vessel to 15 in the second to 5 in the third. There are some differences, however, which are brought out more clearly by the values for the ratio, CaO to P205. These values increase from 1.52 to 1 in the first vessel to 2.13 to 1 in the third. The value of this ratio in the rock itself was 1.46 to 1. These values indicate that the first acid formed has a greater tendency to attack some calcium compound-the carbonate perhaps-other than the phosphate.
INDUSTRIAL A N D ENGI-VEERING CHEMISTRY
October, 1927
Nature of Resulting Products
The exact composition of the mixture resulting from the absorption of nitrogen oxides in a suspension of phosphate rock varies somewhat with the relative quantities used. Calcium nitrate and monocalcium phosphate are the principal products in the ordinary case in which sufficient nitrogen oxides to react with all the rock have been introduced. Small quantities of free phosphoric and nitric acids and probably of other salts and acids are also present. The products primarily obtainable from the solution, although used a t present for fertilizing purposes, are rather hygroscopic. Their conversion to other products of reduced hygroscopicity is desirable from the point of view of their use in fertilizer mixtures. The production of more satisfactory fertilizer materials from the products initially obtainable by the process described in this paper is the object of a separate investigation. Summary
Kitrogen oxides, in concentrations varying from 10 to 16 per cent by weight have been absorbed in suspensions of phosphate rock in water and various nitric acid solutions. The oxides are thus converted very largely into calcium nitrate and the phosphate into the water-soluble form.
1347
The addition of phosphate rock to the absorbing solutions, particularly in cases where a considerable concentration of nitric acid has been built up, increases the degree of absorption of nitrogen oxides, unless the rock is added in too large a quantity. The substitution of either calcium nitrate or monocalcium phosphate for an equivalent quantity of nitric acid in the absorbing solution results in an increase in the degree of absorption. Solutions of these salts up to certain concentrations are also better absorbers than is water alone. The results of a study of the solvent action on the rock indicate that the first nitric acid formed attacks some other calcium compound more readily than i t does tricalciurn phosphate. Acknowledgment
The author wishes to express his appreciation of the friendly interest and advice offered by several of his associates in this laboratory. Especially is he indebted to J. W. Turrentine for his ever-ready counsel and many valuable suggestions, to J. Y. Yee for preparing the nitrogen tetroxide used, and to the members of the analytical department fOT their assistance in connection with the analyses.
Synthetic Methanol and Ammonia from Butyl Fermentation Gases' By J. C. Woodruff COMMERCIAL SOLVENTS CORPORATION, TERREHAUTE.IND. I
This paper describes the recovery of solvents in the The unit of production in waste gases from the butyl-acetone fermentation expansion of the nitrothe butanol plant is the ferof corn; the separation of these gases into their concellulose lacquer inm e n t i n g v e s s e l , holding stituents, hydrogen and carbon dioxide; the use of the d u s t r y , the production of 40,000 gallons of 8 per cent hydrogen for the commercial high pressure catalytic butyl alcohol by the fermentacorn mash. A t Peoria synthesis of ammonia; and finally, the large-scale tion of corn has reached a twenty-six such fermenters production of methanol from hydrogen and carbon stage where the utilization of are each day inoculated with dioxide by means of the modified ammonia equipment. by-products becomes a feasipure cultures of Clostridium ble matter. Themost imporacetobutylicum (Weizmann), tant of these waste materials is the gas evolved during the resulting in a bacterial action which is complete within 48 t o course of the fermentation. 7 2 hours. The rate of gas evolution during this period is To give a n idea of the quantity of this gaseous mixture shown in Figure 1 plotted against the age of the fermentaof hydrogen and carbon dioxide available, the extent of the tion. I n these curves the gassing rate reaches a maximum present manufacture of butanol by fermentation will be of 8000 to 10,000 cubic feet per hour. outlined briefly. There are two plants in this country, The composition of the combined gas from a number both owned by the Commercial Solvents Corporation, one of fermenters is remarkably constant a t 60 per cent carbon located a t Terre Haute, Ind., and the other a t Peoria, Ill. dioxide and 40 per cent hydrogen, with no impurities present Their combined daily capacity calls for 25,000 bushels of except a trace of sulfur compounds and appreciable concorn. The corresponding by-product gas capacity is 4,200,- centrations of butanol, acetone, and ethyl alcohol vapors. 000 cubic feet per day a t Peoria and 1,950,000 a t Terre Owing to the unequal time intervals required for comHaute, the amount of hydrogen being 1,680,000 and 780,000 pletion of the fermentation cycle, the rate of total gas procubic feet, respectively. Carbon dioxide in the above duction varies appreciably in the course of 24 hours. This mixture, when converted t o a weight basis, shows the rather total rate for two typical days at the Peoria plant when startling total of 6900 tons per month. operating on a sixteen-fermenter schedule is shown in Figure 2 . Until recently this entire amount of gas was vented to It is evident that if we are to conserve the entire output the atmosphere. I n the summer of 1925, however, the it must be used a t the average rate, which is represented problem of preventing a portion of this waste was undertaken. by the horizontal line, indicating 114,000 cubic feet per hour. T o permit such a uniform consumption a storage Amount and Composition of Gas Available of a t least 360,000 cubic feet capacity must be available, The first step in its solution involved a determination as given by the shaded area on the graph. of the total amount of gas available, its rate of formation, Recovery of Solvent Vapor and its exact composition. The first valuable product to be obtained from butyl Presented before the Midwest Regional Meeting of the American Chemical Society, Chicago, Ill., May 27 and 28, 1927. fermentation gas was its solvent vapor content, which
WING to the great
0
