INDUSTRIAL A N D ENGINEERING CHEMISTRY
September, 1929 (11) (12) (13) (14) (15) (16) (17)
Michaelis, Canadian Patent 173,128; C. A , , 12, 155 (1918). Middleton, P k a r m . J . , 113, 98, 130 (1924). Middleton, Analyst, 63, 201 (1928). Mita, Arch. ezpcl. Paik. Pharmakol., 104, 276 (1924). Xijk, U.S. Patent 1,532,772; C. A , , 19, 1710 (1923). Nitardy, U. S. Patent 1,632,309; C. A , . 21, 2478 (1927). Nitardy and Tapley, Convention Am. Pharm. Assocn., Portland, Me. (August 20 t o 25, 1928).
(18) (19) (20) (21) (22) (23) (24) (25)
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Palkiu, Murray, and Watkins, IND. ENG.CHEM..17, 612 (1925). Rowe, I N D . ENG.CKEY., 16, 896 (1924). Rowe, J . Pkarnacol., 21, Proc. 213 (1923). Schobig, J. A m . Chem. Soc., 2 2 , 210 (1894). Siler, Sck;'eii. Apolh. ZLg., 63, 257 (1925). Wasteson, Svensk F a r m T i d . , 26, 473 (1922). Wische and Zechner, Phavm. Monatsk., 6, 133 (1924). Zechner and Wische, I b i d . , 6, 464 (1924).
Catalysts for the Formation of Alcohols from Carbon Monoxide and Hydrogen IV-Decomposition
and Synthesis of Methanol by Catalysts Composed of Zinc and Chromium Oxides1 D. S. Cryder and Per K. Frolich
DEPARTMENT O F CHEYICAL ENGINEERING. MASSACHUSETTS IXSTITUTE OF TECHSOLOGY, CAMBRIDGE, ~IASS.
Experiments on the decomposition of methanol in the presence of catalysts composed of the oxides of zinc and chromium show that an excess of chromium oxide gives rise to reactions producing appreciable amounts of carbon dioxide and unsaturated hydrocarbons. With catalysts containing excess zinc oxide the main products are carbon monoxide and hydrogen, a sharp maximum in activity occurring at a catalyst composition of about Zn,8Cr12.The relatively constant percentage of formaldehyde indicates its intermediate formation in the decomposition of methanol. Using the same catalysts for the reverse reaction, it is found that the production of methanol from carbon mon-
oxide and hydrogen parallels very closely the formation of carbon monoxide and hydrogen in the decomposition experiments. Those catalysts which give the highest percentages of carbon monoxide and hydrogen in the decomposition of methanol also give the maximum yield of alcohol in the synthesis. Besides throwing additional information on the reactions in question as well as on the general behavior of the type of catalysts involved, the results are in line with previous work on zinc-copper catalysts, demonstrating the suitability of the decomposition method as a criterion in the selection of catalysts for the high-pressure synthesis of methanol.
. . . . . .. . . . . . . . PREVIOUS paper from this laboratory (7) dealt with the atmospheric decomposition of methanol by catalysts composed of zinc and copper. The results showed that, other variables being kept constant, the extent to which the methanol was decomposed, as well as the type of products obtained, depended on the ratio of zinc to copper in the catalysts. A subsequent paper (8) giving the results of an investigation of the synthesis of methanol from carbon monoxide and hydrogen a t high pressures, using the same zinc-copper catalysts, proved that there exists a very close correlation between the two processes. Those catalysts which gave the highest percentage decomposition into carbon monoxide and hydrogen a t atmospheric pressure also gave the highest percentage conversion of carbon monoxide and hydrogen into methanol, when high pressures were employed. The present paper is a continuation of this work, being a discussion of catalysts composed of zinc and chromium oxides.
A
Previous Work
Some published data are available on the decomposition as well as the synthesis of methanol using the oxides of zinc and chromium. Sabatier, the first to study the decomposition of primary alcohols over metallic oxide catalysts, found that zinc oxide was more active than chroniium oxide in the decomposition of methanol and that zinc oxide was principally dehydrogenating in action while chromium oxide was principally dehydrating in character. Furthermore, the catalytic activity of chromium oxide when prepared from Received April 17, 1929. Presented before the Division of Industrial and Engineering Chemistry a t the 77th Meeting of the American Chemical Society, Columbus, Ohio, April 29 t o May 3, 1929 1
the trioxide differed from its activity when prepared from the hydroxide, while the specific dehydrating or dehydrogenating effect (18) depended on the temperature of calcination. Patart (14) observed that a combination of the two oxides as chromates gave better results in the decomposition of methanol than either oxide alone. More recently Smith and Hawk (20) have made a study of the decomposition of methanol using a wide variety of catalysts. Their results are of particular interest, from the fact that, out of thirty-six different mixtures of oxides used as catalysts, among the best is a catalyst which consists of zinc and chromium in the ratio of 4 to 1. Moreover, they showed by x-ray examination that the zinc oxide and chromium oxide are in actual chemical combination. Morgan, Taylor, and Hedley (16) have pointed out the superiority of a basic zinc chromate catalyst over one of zinc oxide alone in the synthesis of methanol from carbon monoxide and hydrogen. The patent literature contains numerous references to zinc oxide alone (6) or in combination with chromium oxide (2, 6, 10, 11, 12, 16, 24) for the production of methanol and other oxygenated compounds from carbon monoxide and hydrogen. One patent (22) mentions the particular use of a basic zinc chromate of the composition 4ZnO.lCr03. As in the case of zinc-copper catalysts, it is emphasized that the more basic oxide must be in preponderance and that the entering gases must be free from contact with iron. Preparation of Catalysts CATALYSTS CONTAINING hfORE THAX 50 MOL PER CEKT ZINC-Preliminary experiments were carried out as follows to determine the best methods for preparing a uniform catalyst with a high activity:
I S D C S T R I A L d S D ESGI-VEERISG CHEMISTRY
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(a) A solution of the mixed zinc and chromium nitrates was evaporated to dryness on pumice, and ground to 50 mesh. The resulting mixture was calcined to drive off the oxides of nitrogen and treated with methanol vapor a t 220" C. for 1 hour. When the temperature was slowly raised to 340' C., the catalyst invariably showed very little activity in the decomposition of the methanol vapor. (6) C. P. zinc oxide (200 mesh) was suspended in water and the calculated amount of chromium trioxide in solution added. The resulting mixture, when evaporated to dryness, heated 4 hours a t 220" C in an atmosphere of nitrogen, and subjected t o methanol vapor as above, proved to possess high catalytic activity. ( c ) Zinc hydroxide, precipitated from a solution of the nitrate with ammonium hydroxide and given the same subsequent treatment as in the preceding example, showed a relatively high order of activity.
T-ol. 21, s o . 9
sesyuioxide (green) at higher temperatures. Apparently thi. intermediate compound is very stable toward reduction by methanol vapor. From the results of a series of experiments employing various methods of effecting the reduction, it wai concluded that it was impractical to prepare uniform catalysts containing an excess of chromium trioxide, owing to the complete alteration of the surface upon heating and the incomplete reduction of the black intermediate compound by metharlol vapor. Bccordingly the following standard procedure was adopted: Equivalent amounts of zinc hydroxide and chromium trioxide were mixed together and added to a calculated amount of chromium nitrate in solution. The mixture wai heated and the excess chromium precipitated as hydroxide. The resulting catalysts exhibited normal behavior when reduced by methanol vapor. Analytical Methods
2" 0 IO0
c.
20 00
40 40 COYPOSITION
0
or
40
UTNYST
M)
IW
20
0
MOL%
M e t h y l F o r m a t e w i t h Zinc-Chromium Catalysts of Various Compositions
On the basis of these experiments the following standard procedure for preparation of these catalysts was adopted: An aqueous solution of 0.6 mol per liter of chemically pure zinc nitrate was heated to 86" C. and the zinc precipitated by the addition of dilute ammonium hydroxide (1:l) with constant stirring. The clear solution was decanted and the precipitate washed three times by decantation, using 1 liter of water a t 86" C. for each washing. After filtration the hydroxide was again washed with 1 liter of water a t 86" C. The resulting fairly dry hydroxide was stirred thoroughly with water and this suspension was used as a stock for all catalysts. The zinc oxide value was found by removing measured amounts of the thoroughly stirred suspension, evaporating to dryness, and calcining in a porcelain crucible to the oxide. A stock solution of chromium trioxide was prepared and its chromium value obtained by adding a measured amount to an acidified solution of potassium iodide and titrating the liberated iodine with thiosulfate. A catalyst was prepared by adding the thoroughly shaken stock suspension of zinc hydroxide to the chromium trioxide solution and evaporating while stirring. The resulting mixture was dried in an electric oven a t 110" C., ground to 60 mesh, heated in an atmosphere of nitrogen for 4 hours at 220" C. to secure complete dehydration, and bottled immediately. CSTBLYSTS CONTAISING J I O R E THAN 60 P E R C E X T CHROmuw-Special methods are necessary in the preparation of these catalysts on account of the behavior of chromium trioxide upon heating. Solid chromium trioxide decompose5 slowly on heating into a lower oxide and oxygen, the reaction proceeding quickly if the temperature is raised above the melting point (1). This decomposition can be explained on the basis that there is first formed an intermediate oxide, chromium chromate (black), which changes to chromium
Catalysts containing chromium in the form of chromium trioxide were completely dehydrated and the chromium determined by the usual iodometric method. Several methods were tried for the analysis of catalysts containing excess chromium in the form of Crz07,the following method being adopted as the most accurate: Chromium was oxidized with sodium peroxide and determined volumetrically with standard iodine and thiosulfate solutions. This gare the total chromium present. It was then assumed that chromium trioxide was present in an amount equivalent to the zinc oxide. From this assumption the amounts of chromium in the form of Cr203 and the ZnO were calculated. This assumption proved to be accurate to within less than 1 per cent, as shown by several direct analyses for the amount of zinc oxide present. Formaldehyde in the liquid product from the decomposition experiments was determined by the iodometric method of Romijn ( 1 7 ) . Nethyl formate was determined by hydrolysis with excess sodium hydroxide and titration of the unused alkali.
2" 0 Cr 100
20 M
40
W CATALYST
M 40
(OwowioH
M 20
IW
0
MOLY.
Figure 2-Total Decomposition of Methanol a t Atmospheric Pressure a n d 340° C a n d S y n t h e s i s at 3000 Pounds Pressu;k (204 A t m o s heres) Using a C o n s t a n t Weight of t g e S a d e Catalyst For decomposition-0.42-gram catalyst For synthesis-1.0-gram catalyst
Apparatus a n d Procedure
The apparatus used in the decomposition and synthesis experiments was identical with that employed in the previous work with zinc and copper catalysts ( 7 ) . The decomposition apparatus consisted essentially of an electrically heated glass tube through which methanol vapor was passed a t a constant rate. The liquid decomposition products were condensed
INDUSTRIAL, A N D ENGINEERISG CHE;MISTRY
September, 1929
in bulbs filled with liquid methanol and cooled with solid carbon dioxide, the gaseous products being collected and measured in a calibrated copper cylinder. I n the synthesis of methanol from carbon monoxide and hydrogen, the entering gas mixture passed through a copperlined purifier containing calcium chloride, soda lime, and activated charcoal. From the purifier, by means of copper capillary tubing, the gas was led to a copper-lined reaction chamber immersed in a lead bath. The temperature of the lead bath mas read by means of a thermocouple. From the reaction chamber the gases passed successively through a water-cooled condenser, a product collector, and a wet meter, to the exit line. Gas samples were taken after the gases had passed through the wet meter. The decomposition was carried out a t 340" C., using a constant weight of catalyst (0.42 gram). The experiments on the syntheses of methanol were carried out :it 350" C., using 1 gram of the same catalyst. The total pressure employed was 3000 pounds per square inch (204 atmospheres) and the rate of flow of exit gas was regulated to 30 liters per hour. The supply gas used analyzed as follows: carbon dioxide 0.1, oxygen 0.3, carbon monoxide 27.7, hydrogen 69.4, nitrogen 2.5 per cent.
869
decomposition of methanol, observed that there existed a considerable amount of low-boiling constituent in the liquid condensate obtained from the use of a catalyst containing chromium oxide. This was probably dimethyl ether, since Brown and Galloway (3) have definitely proved the existence of this compound as a by-product in the synthesis of methanol from carbon monoxide and hydrogen, when zinc oxidechromium oxide catalysts were employed. It is also highly probable that further dehydration of the dimethyl ether t o ethylene can take place according t o reaction 2. In fact, Sabatier (19) indicated the complete dehydration of methanol according t o the reaction: 2CH3OH = CZH4
+ 2HzO
(3)
when the dehydrating catalysts thoria, alumina, and blue oxide of tungsten were employed.
Discussion of Results
DECOMPOSITIOX EXPERILIENTS-Figure 1 illustrates the influence of catalyst composition on the trend of the reactions taking place in the decomposition of methanol. It will be noticed that catalysts containing less than 50 per cent zinc give rise t o side reactions producing appreciable amounts of carbon dioxide and unsaturated hydrocarbons. Regarding the formation of carbon dioxide from carbon monoxide, n-ith the deposition of carbon, a superficial examination of the spent catalyst containing excess chromium showed no alteration in appearance from that of the freshly reduced catalyst. Moreover, Tropsch and Roehlen (23)
lo
0 2. 0 C I IO0
20 a0
eo
40
eo CATUIST
LO
00
40 20 COYPOSITWN MOL %
0
Fiqure 4-Total Decomposition of Methanol a t Atmospheric Pressure a n d 340" C., a n d Synthesis a t 3000 Pounds Pressure (204 Atmospheres) Using a s a Basis 1 cc. of S a m e Catalystd
The formation of unsaturates might also occur through the intermediate formation of acetaldehyde as follows: 2CO CH,OH = CH3CHO CO, (4) the acetaldehyde then being hydrogenated to ethyl alcohol and subsequently dehydrated t o ethylene according to the following reactions: CHICHO Hz = CHaCHZOH (5)
+
+
+
CHsCHzOH = CzH4
I / / 1 / / 1 1 ' "300
320
Y O
380
380
I 400
TLYCLnATURL.C.
Figure 3-Effect of Change of Temperature on Activity of a Z i n c - C h r o m i u m Catalyst for Decomposition of Methanol Catalyst composition. zinc 75, chromium 25
found very little decomposition of carbon monoxide over chromium oxide at 400" C. Several reactions might be formulated which would represent the formation of unsaturated hydrocarbons, among which may be noted the following: Such a dehydration of methanol is highly protiable over a catalyst containing excess chromium oxide. Reference has already been made to the work of Sabatier (S), who showed that the principal action of chromium oxide is one of dehydration. Regarding reaction 1, Smith (ZOO), in his experiments on the
+ Hz0
(6)
All the above reactions are thermodynamically sound, but it is the opinion of the writers that reaction 1, 2, or 3, which latter is the sum of the first two, offers the most probable explanation for the formation of ethylene. The formation of carbon dioxide can be readily accounted for by the water-gas reaction: CO
+ HzO
= COz
+ Hz
(7)
since chromium oxide is well known as a water-gas conversion catalyst. Smith and Hawk have also shown that those catalysts prepared from zinc oxide and chromium trioxide contain zinc and chromium in chemical combination even after reduction, and exhibit the properties of neither zinc oxide nor chromium oxide alone. This offers an explanation why the specific action of chromium oxide (CrzO,)is not shown except in the catalysts containing excess chromium, for it mill be remembered that such excess was added in the form of chromium hydroxide. X o attempt was made to obtain very extensive data on the catalysts containing excess chromium, although it will be seen from Figure 2 that the activity of these catalysts in the decomposition of methanol is of substantially the same relative order of magnitude throughout.
870
IiTD C S T R I A L A N D ENGILITEERINGCHEMISTRY
When, however, the composition of the catalyst exceeds 50 mol per cent zinc, there is a radical change both in the nature and amount of products. This agrees with what has been observed in the case of the zinc-copper catalysts. The reaction is one of fairly clean-cut decomposition into carbon monoxide and hydrogen, with very little side products. A comparison of Figures 1 and 2 shows that those catalysts which give the highest total decomposition also show the highest percentage of carbon monoxide in the products, the carbon monoxide curve having the same general shape
Figure 5-Comparison of Methanol Decomposition a t 340° C. a n d Atmospheric Pressure with Synthesis a t 350' C. a n d 3000 P o u n d s (204 Atmospheres) Using S a m e Catalysts
as that of the total decomposition curve. As the composition of the catalyst approaches that of pure zinc oxide, the type of reaction again changes, as indicated by the curves in Figure 1. Here, as in the case of the zinc-copper catalysts, the specific effect of the predominating amounts of zinc oxide is to cause a significant increase in the proportion of methyl formate and a corresponding decrease in the carbon monoxide content. A further point of interest in Figure 1 is the relatively constant percentage of formaldehyde throughout the entire range of catalysts. Passing to the total decomposition obtained with the various catalysts, Figure 2 shows that a sudden increase in activity occurs a t a composition of 78 mol per cent zinc. The shape of this curve checks fairly closely that of the decomposition curve obtained by Smith and Hawk (ZO), whose best zinc oxide-chromium oxide catalyst contained 80 mol per cent zinc. This same catalyst (4Zn:lCr) is noted in a patent already cited (23) as being highly suitable for the synthesis of methanol from carbon monoxide and hydrogen. The great increase in activity of a promoted zinc oxide over that of a catalyst containing zinc oxide alone, as obtained in these experiments, is at variance with the conclusions of both Smith and Hawk (20) and Storch (21). However, a study of the differences in catalyst preparations reveals discrepancies which may account for the differences in the results obtained. The zinc oxide-chromium oxide catalyst used by Smith and Hawk in their decomposition experiments was prepared from c. P. zinc oxide and chromic acid in the same manner as that employed in the preparation of catalysts used in these experiments. The zinc oxide catalyst which was taken for comparison, however, was prepared from precipitated zinc carbonate, and it is highly probable that the surface structure of such a zinc oxide differs materially from that of the zinc oxide used in the zinc oxidechromium oxide catalysts. hloreover, other zinc oxides used by Smith showed a much lower activity than the one which he used as a standard for comparison. Storch prepared but one similar zinc oxide-chromium
1'01 21, No. 9
oxide catalyst with less than 9 mol per cent chromium. This catalyst does not lie in the range of the highly active catalysts Storch's observations that pure chromium trioxide catalysts are practically inactive and that catalysts prepared from chromium hydroxide are only slightly more active, check the results of these experiments. His results on the synthesis of methanol are also in accord with the data obtained in these experiments, in showing the increase in activity of the chromium-promoted catalysts. The more active catalysts, such as Zn75-Cr25, when subjected to increasing temperatures show a proportionate increase in activity. This is brought out in Figure 3, which also illustrates the effect of such higher temperatures on the subsequent activity at a lower temperature. A catalyst, once heated considerably above a definite temperature, does not maintain its original activity when cooled again to the same temperature. For example, if the above catalyst is heated from 340" C. to 390" C., and then cooled again to 340" C., it will be noted that it has lost almost 50 per cent of its original activity. Several runs were made to determine the life of these active mixtures. One run was discontinued after a catalyst had been in constant use for thirty-six hours a t 340" C. During this time its activity was unimpaired and there was no variation in the relative amounts of the products of the reaction. A further point of interest is brought out in Figure 4. For a given weight of catalyst the density changes considerably with a change in composition. Thus there is a fourfold increase in specific volume for a change in composition from 50 mol per cent zinc to 77 mol per cent zinc. This increase in volume must be expected to be accompanied by a corresponding increase in free surface per unit weight of catalyst, and since the extent of catalytic action is primarily a function of surface exposed, it would be better to express the activity on the basis of catalyst surface rather than weight. I n the absence of satisfactory means of estimating the surface of a catalyst, it is a t least interesting to compare the activity on the basis of unit volume. This is done in Figure 4. Although recalculation of the data from
I I 10 a?Cr 25
20 CATALYST
I a5
coumsmu u a .k
IS
Figure 6-Effect of Increase i n T e m perature o n Yield of Methanol f r o m Carbon Monoxide and Hydrogen, Using Zinc-Chromium Catalysts
weight to volume basis is open to criticism, since the results thus obtained for various catalyst compositions are not strictly comparable, it is nevertheless seen that the same general shape of curve is obtained. However, the maximum decomposition has shifted to catalysts containing 55 t o 60 per cent zinc. This is probably caused by the sudden decrease in density of the catalysts in the neighborhood of 80 mol per cent zinc. Grober ( 9 ) made a study of the system zinc oxide-chromium trioxide and water and showed that the basic chromate 4Zn0.1Cr03 can exist over quite an appreciable range of chromium trioxide in the solution which was in equilibrium with it. This basic chromate is evidently highly hydrated during the course of preparation of the catalysts in this range of composition as is shown by the tendency toward gel formation. The formation of such
INDUSTRIAL A S D E,YGISEERIAYG CHEMISTRY
September, 1929
highly hydrated gel would tend to increase the volume enormously for a given weight of catalyst and account for the sudden rise in activity of catalysts in the region of 80 per cent zinc when plotted on a constant weight basis. SYNTHETIC EXPERIJIEKTS-In Figures 2, 4, and 5 the results of the experiments on the synthesis of methanol are presented in comparison with the decomposition data. It will be seen that the two sets of curves have the same general form and that those catalysts which possess the greatest activity in the decomposition of methanol a t atmospheric pressure also show the greatest activity in the synthesis of methanol a t high pressures. There exists an apparent discrepancy between the decomposition and synthesis curves of Figure 4 with a pure zinc oxide catalyst. It will be remembered, however, that the mechanism of the decomposition of methanol with pure zinc oxide differs from the mechanism using zinc-chromium catalysts. With the former a large amount of methyl formate is obtained, with the latter almost entirely carbon monoxide and hydrogen. Since the synthesis of methanol 100
1 i 1 I l
l l l l l
871
trioxide upon heating, resulting in a chemically inert compound and a complete alteration of catalytic surface. The maximum activity for a given weight of catalyst is reached a t a composition of approximately 80 mol per cent zinc. However, owing to the sudden decrease in density of catalysts with this composition, the maximum activity, using a constant volume as the basis of comparison, is shifted to between 55 and 65 mol per cent zinc. In line wit.h previous work on copper-zinc catalysts, the results of the decomposition experiments indicate intermediate formation of formaldehyde. This is evidenced by the fact that the percentage of formaldehyde in the decomposition products remains practically constant. If formaldehyde were formed from carbon monoxide and hydrogen, then a t high concentrations of carbon monoxide and hydrogen the formaldehyde should be noticeably increased. This, however, is not the case. Another point in favor of formaldehyde being formed intermediately is the change in the composit,ion of the products when pure zinc oxide is used as a cat'alyst. In this case the methyl formate content is greatly increased and the carbon monoxide content correspondingly reduced. This is most readily explained by assuming that formaldehyde is the intermediate product in the decomposkion of methanol and that it can participate in either one of the two following reactions: HCHO = CO
+ Hz 0
BHCHO = CH,OC/ \H Figure '/--Distillation Curve for Liquid Product Obtained f r o m Carbon Monoxide a n d Hydrogen a t 3000 Pounds (204 Atmospheres) a n d 350' C., Using Zinc-Chromium Catalyst Catalyst composition, 4Zn 1Cr
is from carbon monoxide and hydrogen, the amount of carbon monoxide and hydrogen in the decomposition products should be the determining factor for comparison rather than the total decomposition. To put it more concretely, those catalysts which are most effective in carrying out the decomposition of methanol should be the most active in effecting the reverse reaction, provided the mechanism is the same. Thus, Figure 5 shows clearly that the percentage of carbon monoxide obtained in the exit gases from the decomposition of methanol serves as a valuable guide in the selection of catalysts for the synthesis of methanol from carbon monoxide and hydrogen. The effect of temperature on the methanol yield is shown in Figure 6. The optimum temperature lies between 370" and 390" C. for the catalysts investigated. Moreover, the catalysts containing higher percentages of zinc appear to be less stable toward high temperatures. This is very likely due to sintering, since equilibrium was certainly not established, as will be seen from the increasing yields at higher temperatures shown by a catalyst containing 7 5 per cent zinc, as well as from the results of previous publirations (13). One catalyst (ZnijCrzi) was run continuously for 15 hours and the liquid product collected for identification. The distillation (Figure 7 ) in a micro-fractionating column ( 4 ) showed that practically pure methanol was produced. Conclusions
Chromium oxide x-ithin certain limits exerts a marked promoter effect on tjhe activity of zinc oxide. The effect is far more pronounced if the oxide is prepared from chromium trioxide rather than chromium hydroxide. It appears impossible, however, to prepare an active catalyst, containing excess chromium trioxide. The low activity of such catalysts is due t o a chemical and physical change in the chromium
Any catalyst, such as pure zinc oxide, which favors the formation of methyl formate, would of necessity decrease the amount of formaldehyde decomposing into carbon monoxide. The experiments on the syntheses of methanol using the same catalysts show rather conclusively that those catalysts which are most active in the decomposition of methanol into carbon monoxide and hydrogen a t atmospheric pressure are the most active in the synthesis of the alcohol from carbon monoxide and hydrogen a t high pressure. The results agree in this respect entirely with similar data obtained using zinc-copper catalysts and further confirm the conclusion that the decomposition method of testing catalysts is a valuable criterion for the selection of catalysts for the high pressure syntheses of methanol. Acknowledgment
The writers wish to acknowledge the cooperation and assistance given by M. R. Fenske during the course of this work. Literature Cited (1) Abbegg, Handbuch der anorganischen Chemie, p. 327.
(2) (3) (4) (5) (6)
(7) (8) (9) (10)
(11) (12)
(13) (14) (15) (16)
(17) (18) (19)
(20) (21)
(22) (23) (24)
Badische Anilip-Soda Fabrik, French Patent 58,816 (1924). Brown and Galloway, IND.ENG.CHEM.,21, 310 (1929). Cooper and Fasce, I b i d . , 20, 420 (1928). Dreyfus, German Patent 262,494 (1926). Dreyfus, German Patent 263,503 (1926). Frolich, Fenske, and Quiggle, IND.END.CHEX.,20, 694 (1928). Frolich, Fenske, Taylor, and Southwick, I b i d . , 20, 1327 (1928). Grober, Z. anorg. Chem., 7, 139 (1911). Johnson,British Patents 264,819 (1926);254,760 (1925); 229,714 (1925). Johnson, German Patents 227,147; 238,319 (1923). Lazier, German Patent 2i2,555 (1926). Lewis and Frolich, IND.ENG.CHEM.,20, 285 (1928). Lormand, I b i d . , 17, 430 (1925). Morgan, Taylor, and Hedley, J . S o t . Chem. I n d . , 47, l l i T (1928). P a t a r t , German Patent 250,562 (1923). Romijn, Z . anal. Chem., 36, 19 (1897). Sabatier, "Catalysis in Organic Chemistry," p, 674 (1923). Sabatier, Comfit. rend., 185, 17 (1927). Smith and Hawk, J . Phrs. Chem., 32, 414 (1028). Storch, I b i d . , 32, 1743 (1928). Synthetic Ammonia & Nitrates, L t d . , British Patent 275,345 (1927). Tropsch and Roehlen, Chem. Zentr., 1, 3298 (1926). Woodruff and Bloomfield, U. S. Patent 1,625,925 (1927).
