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INDUSTRIAL A N D ENGINEERING CHEMISTRY
(61) Ketslakh, M. M., Rudkovskii, D. M., and Suknevich, I. F., Zhur. Priklad. Khim., 23, 215-19 (1950); J. Applied Chem., U.S.S.R.,23,221-4 (1950). (62) Kirk, R. E., and O t h e r , D. E., ed., “Encyclopedia of Chemical Technology,” Vol. 6, pp. 738-69, New York, Interscience Publishers, 1951. (63) Kress, B. H., Brit. Patent 625,281 (June 24, 1949). (64) Le Fsve, G. M., and Scheurer, P. G., J . A m . Chem. SOC.,72, 2464-5 (1950). (65) McBee, E. T., U. S. Patent 2,537,777 (Jan. 9, 1951). (66) McBee, E. T., Hass, H. B., and Robinson, I. M., J . Am. Chem. Soe., 72, 3579-80 (1950). (67) McBee, E. T., and Rapkin, E., Ibid.,73, 1366 (1951). (68) McBee, E. T., and Robb, R. M., U. S. Patent 2,533,132 (Dec. 5, 1950). (69) Zbid., 2,533,133 (Dec. 5, 1950). (70) Zbid., 2,544,560 (March 6, 1951). (71) Zbid., 2,545,430 (March 13, 1951). (72) McBee, E. T., and Sanford, R. A., J . A m . C h a . Isoc., 72, 4053-5 - - - ~- (1950). .----,(73) Zbid., pp. 5574-5. (74) Niagara Alkali Co., Blume, P. W., et al., Brit. Patent 631,008 (Oct. 25, 1949). (75) Norton, T. R., J. Am. Chem. SOC.,72, 3527-8 (1950). (76) N. V. de Batsafache Petroleum Maatachappij, Brit. Patent 633,211 (Dec. 12, 1949). (77) Park, J. D., et al., J. Am. Chem. Soc., 73, 1329-30 (1951). (78) Park, J. D., Lycan, W. R., and Lacher, J. R., Ibid., 73, 711-12 (1951). (79) Park, J . D., Snow, C. M., and Lacher, J. R., Ibid., 73, 2342-5 (1951). (80) Perkins, M. A., U. S. Patent 2,549,988 (April 24, 1951). (81) Randall, M., Z6id., 2,547,139 (April 3, 1951). (82) Reid, R. J., Ibid., 2,537,630 (Jan. 9, 1951). (83) Renfrew, M. M., Ibid., 2,534,058 (Dec. 12, 1950).
Vol. 43, No. 9
(84) Ritchie, M., and Winning, W. I. H., J. C h a . Soc., 1950, 357983. (85) Ibid., pp. 3583-90. (86) Roe, A., and Teague, C. E., Jr., J . Am. Chem. SOC.,73, 687-8 (1951). (87) Salisbury, L. F., U. S. Patent 2,519,199 (Aug. 15, 1950). (88) Sauer, J. C., Ibid., 2,549,935 (April 24, 1951). (89) Sen Gupta, 8. B., Chakravarti, D. P., and Dutta, A. P., J. Indian Chem. SOC.,Znd. Eng. News Ed., 11, 1 3 9 4 5 (1948). (90) Shechter, H., and Conrad, F., J. Am. Chem. SOC.,72, 3371-3 (1950). (91) Simons, J . H., U. S. Patent 2,522,968 (Sept. 19, 1950). (92) Simons, J. H., ed., “Fluorine Chemistry,” Vol. 1, New York, Academic Press, Inc., 1950. (93) Spina, J. A., U. S. Patent 2,511,818 (June 13, 1950). (94) Swinehart, C. F., Zbid., 2,534,638 (Dec. 19, 1950). (95) Tarrant, P., and Brown, H. C., J. Am. Chem. SOC.,73, 1781-3 (1951). (96) Te Grotenhuis, T. A., and Swart, G. H., 0. S. Patent 2,548,504 (April 10, 1951). (97) Towle, W. L., U. 6. Patent 2,534,485 (Dec. 19, 1950). (98) U. S. Dept. of Commerce, Bur. of the Census, “Facts for Industry, Inorganic Chemicals,” M19a-31 (1951). (99) U. 8. Tariff Commission, Chemical Division, “Facta for Industry,” Series 6-275 and 86 (1951). (100) Waterman, H., U. S. Patent 2,531,372 (Nov. 21. 1950). (101) Webb, G. A.,Zbid-, 2,527,606 (Oct. 31, 1950). (102) Weissert, F. C., Behrend, E. B., and Rriant, R. C., Zbid., 2,537,627 (Jan. 9, 1951). (103) U’ibaut, J. P., and Bloem, G. P., Rec. trav. chim., 69, 586-92 (1950). (104) Yamasuga, K., and Chiba, K., J . SOC.OTQ. Synthetic Chem.. J ~ J K I7, X ,125-33 (1949). RECEIVED June 19, 1951.
Hydrogenation and Hydrogenol ysis HAROLD W. FLEMING THE GIRDLER CORP., LOUISVILLE, KY.
During 1950 there have been important developments of the Fischer-Tropsch process, including initial operation of the first commercial synthesis plant in the United States, a moving “fixed catalyst bed‘’ with liquid coolant, and a nitrided iron catalyst which appears to resist oxidation and deposition of free carbon during the synthesis. Selective hydrogenation of acetylenic compounds in gas streams containing ethylene and hydrogen may make available large quantities of ethylene for the chemical industry. The petroleum industry continues to investigate the hydrogenation of double bonds for the production of aviation gasoline, saturation of aromatic hydrocarbons in catalytic cycle stock, and destructive hydrogenation of gas oils. The trend in ammonia synthesis studies is toward the use of a fluidized “fixed bed” of promoted iron catalyst to obtain higher conversions per pass. There i s increased interest in a supported copper chromite type of catalyst and in the substitution of other metals such as nickel, cobalt, zinc, and cadmium for copper.
OR the first time this review includes the Fischer-Tropsch process, with a brief summary of the earlier literature added t o t h e fuller coverage of theliterature made available in 1950. T h e hydrogenation of coal is not reviewed because the Bureau of Mines is the principal contributor in this field and their work is summarized each year in a n annual report (19, 17, bS, 30, 3 1 , 4 0 , 4 l , 4 8 , 5 9 , 5 5 , 8 9 , 1 0 1 , 1 1 8 ,252, 153, 165,166).
F
FISCHER-TROPSCH PROCESS The historical development of the Fischer-Tropsch process has been summarized in many publications (3, 81-84, 149, I@, 164). Because the process has not been included in these annual
significant information Obtained from the operation of cornmercial and pilot plants in Germany and the United States will be discussed briefly before the more detailed summary of the literature for 1950 is given. All the German Fischer-Tropsch p l a n t s i n 1938-44 (141-14s) were operating according t o t h e Ruhrchemie process using the CoTh02-Mg0-kieselguhr catalyst at 180’ to 220’ C., a t either 1 or 10 atmospheres pressure, and with two or three stages with product recovery after each stage. T h e average yield of hydrocarbons ranging from propane-propylene t o waxes of 2000 molecular weight was 150 grams per cubic meter of (2H2 1CO) gas. T h e space velocity employed was 60 t o 100 volumes of feed gas per volume of catalyst per hour. T h e only outstanding procese development using the cobalt catalyst recycled about three volumes of end gas from the first stage per volume of fresh gas with product condensation after each cycle. This resulted in an increase of 30% in the throughput without sacrifice of yield. The recycle-process gasoline has a 50 to 55 motor octane number as compared with 46 for the older process without recycle.
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September 1951
INDUSTRIAL A N D ENGINEERING CHEMISTRY
I . G. Farbenindustrie operated a pilot plant using a sintered iron catalyst and a hot-gas rccj-cle process (141.-143), The critdyst was prepared by makiiig a paste of iron powder (obtained by decomposition of iron cnnbonyl) with a dilute solution of sodium boratc. The extruded and dried granules were heated i n a hydrogen atmosphere a t 850' C. for several hours before m e in the synthesis, nhich was conducted in the range 320" t o 330" C., 20 atinosphcres, and 0.75-fiecond contact time. The from the coiiverter were recycled through a heat exchanger t u Icinove heat of reaction. Conversion per pass was about i ',k, so t h a t about 100 volunies of recycle gas to 1 of frcsh gas ~iitcrcdthe converter. 4 research octane number of 84 to 86 \ \ :L- obtained for the refined gasoline. .\ similar recyc,lc process (l,$l-lhr3) x a s developed by 1,ui.gi Co. uiiing :L Ruhrcheniie iniddle-pressure (10 to 20 :ttiiii)spheres) conv(.It: r n-ith iron catalysts in place of c o h l t t::lJ-sts. Tlic 1w.t iron c:tt:i!yst developed by Lurgi has the coinpositiori: iroli, 100; copper, 25; aluminum oxiilcs, ium o \ i c l i s , 2 ; hilicon dioxide, 30. This catalyst pwfI ,~IIIJ is rctiucctl i i i v i t u {vith hydrogen n t 250" to 350" C. for 1 t o 1 l i o i i i :, but rcclwt i o n n.it h synthesis gas is possible. Syntlic,vi. i- -!:ii,tcxcl at ftboiit IS0' CI., and the temperature is raised to 220' iii t w o d:i>.-. Tlic operating pressure is 20 atmosphcw*. 'I1!:(, ~ p : i ( , ei.vlocit\- (volumes of gas per volume of catalyst ! l f ' r l i o i i i , , ~i frc-h ga- is 100, of recycle gas 300, and the tail gas volof tlic frcsh gas volume. It is believed that the life of n.oul~lI I C :ihout one year. Aiiotht~riron C:I t a l \ sed in the recycle process which yield. a tiighcr proIwrt ion of lint, in the product is made by imprcgn:iting I,ti\ii!a~si~ $\.it t i R solution of copper ammonium nitrate t o ol~tain3% by vx.iyht of nict:illic copper in the finished catalyst. The resulting cat:ilyqt is not. highly active and requires a high 01)c-mting tcrnpt~r:rtuxi,but a t this temperz'ture a relatively io\\, boiling product is produced with less catalyst deterioration duc to c-:kI.bon di>po~ition than ~ v o ~ i loccur d with a more active catalyst. The operating tt?nil)erature is 275" C. and pressure is 20 atmospheres. The ep:ice velocity of fresh gas is 100, of recyclc gas fJ00, and thc tail g : i ~volume is 50.570 of the fresh gas volume. Other procesws being developed by I. G. Farbenindustrie in,*iude a liquid-phxse operation in which iron powder prepared iron1 iron carbonyl is mixed with a high-boiling oil and synthesis gas is bubbled through the mixture. This process yields more Diesel oil (of 60 to 70 cetane number) and much less methane and -thane than the hot-gas recycle process. Gasoline from the liquid-phase process operated a t about 300' C. is reported to have a research octane number of 90. Another I. G. Farbenindustrie development iyas an oil-recycle process in which a cooling oil was passed concurrent with the synthesis gas over granules of an iron catalyst (synthctic ammonia type, ferroferric oxide, 2.5% aluminum oxide, and 0.5% potassium oxide). The cooling was effected by recycling the heated oil through an external heat exchanger. The German Synol process (141-143) for the production of alcohols is identical with the Fischer-Tropsch synthesis using an iron catalyst, differing from it only in space velocity of feed gas and operating temperature. Passing a mixture of 1 volume of carbon dioxide, 0.8 volume of hydrogen, and 20 to 50 volumes of recycle gas a t 18 t o 25 atmospheres and 190" to 200" C. over a catalyst which w3s a fused mixture of 97% ferroferric oside, 2.5T6 aluminum oxide, and o.5yOpotassium oxide previously reduced a t about 450" C. with hydrogen yielded about 160 grams of a mixture of hydrocarbons and alcohols per cubic meter of fresh gas. The catalyst wm prepared by burning pure iron in oxygen t o form a molten mass of oxide. Aluminum and potassium nitrate were then added to the melt, and the fused mixture was cooled and crushed to 1 to 3 mm. particle size. The finished preparation contained 97% ferroferric oxide, 2.5% aluminum oxide, 0.2 t o 0.6% potassium oxide, 0.16% sulfur, and 0.03% carbon. I t s bulk (I.
1979
density was about 2.0 after crushing. This catalyst w a s reduced for 50 hours in pure dry hydrogen a t about 450" C . The Synol process is of interest in n discussiori of the FischerTropsch reaction because of the sirnilarity of process conditions, catalysts, and coke formation. The same catalyst when used a t a higher temperature, as in the hot-gas recycle process, yields chiefly hydrocarbons Tyith only 6 to 10% of alcohols, as compared n i t h yields as high as 70y0 of alcohols in the Synol process using a recycle ratio of about 100 with the drying of the gas on each cycle. The total conversion is more than 90% to alcohols plus hydrocarbons with only a sniall amount of carbon dioxide produced. Possibly the formation of the normal straight-chain alcohols which constitute the bulk of the Synol alcohol product precedes that of olcfins on this iron catalyst a t 20 atmospheres in the temperature range of 190" t o 325" C. Carbon deposition apparently is proceeding a t an appreciable velocity, even a t 190" t o 225' C., under the conditions of the Syno1 process. The formation of carbon a t 300" to 325' 6.in the hot-gas recycle or the fluidized iron processes, therefore, is not pecuiiar to the elevated temperature, although the rate of carbon fomiation is greater a t the higher temperatures. In the United States (141, 142) several oil companies have developed a fluidizcd-iron catalyst process for producing motor gasoline by the Fischer-Tropsch process. In pilot plant work on this fluidized-iron process, doubly promoted synthetic ammonia catalysts, 9?yoferroferric oxide, 2.5% aluminum oxide, and 0.5% potassium oxide have been used. The fused catalyst is ground finely and reduced completely by hydrogen before use. I t is then introduced into the converter while protected by an inert atmosphcre. Pilot plant operation is conducted usually a t 300' to 325" C., 20 atmospheres pressure, and a recycle of 3 t o 4 volumes of end gas per volume of fresh feed. The latter is composed of 1.8 to 2 volumes of hydrogen t o 1 volume of carbon monoxide, prepared by oxidation of natural gas with oxygen-steam mixtures a t 300 to 400 pounds per square inch and 1200" 6. The synthesis operation is in a "fixed" fluidized bed. Carry-over of catalyst is completely avoided by the use of Aloxite filters in expanded section of the top of the converter. Catalyst density in the fluidized bed is 60 t o 80 pounds per cubic foot a t the start. This density decreases during the first two t o 14 days of operation to 10 to 20 pounds per cubic foot because of "spalling" of the catalyst induced by carbon formation. With a hydrogen-rich total feed gas, 1600 hours of continuous operation were achieved and with a carbon dioxide-rich feed gas, only about 400 hours. Operation is limited to a gas velocity of 1.5 to 2.5 linear feet per second; a t this velocity conversions of 90 to 95% are obtained per pass so that multistage operation is unnecessary. Operation with a carbon dioxide-rich feed gas results in a product which is chiefly gasoline (predominantly olefinic) with minor amounts of Diesel oil and osygenated compounds. The yield of wax is less than 1% but this is sufficient to came occasional defluidization of the bed. The gasoline with very little refining is a suitable motor fuel of about 75 motor octane number which can be appreciably increased by addition of polygasoline from the C? and CSolefins and by tetraethyllead. Based on this pilot plant Tvork, a plant of about 8000 barrels per day has been designed and erected a t Brownsville, Tex. This plant is now in the shakedown stage of initial operation (42). Synthesis gas is to be made by reacting natural gas a t about 400 pounds per square inch with oxygen and steam in two vessels, each about 2000 cubic feet in volume. The synthesis converters reportedly will be six in number, each of about 3500 cubic feet volume. They are t o be fed with 350,000,000 cubic feet of fresh synthesis gas and 750,000,000 cubic feet per day of recycle gas. The U. S. Burcau of Mincs has developed a process in which the heat of reaction is removed from a granular or pelleted catalyst bed by the evaporation of an oil introduced along with the synthesis gas ( 1 5 2 , 1 5 3 ) . The converter contains no metal heat-exchange surfaces and the Operation is essentially adiabatic. Temperature
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INDUSTRIAL AND ENGINEERING CHEMISTRY
control is precise; there is no radial temperature gradient and the vertical gradient is about 25' C. These studies led to a similar process in which the heat of reaction is removed by circulating an oil through the catalyst bed and a heat exchanger. The yield per unit of reactor volume is eight to ten times larger when the gaseous hydrocarbon yield is about the same as in the Ruhrchemie process. Based on this development work, a gas synthesis demoristratiori plant of 100 to 150 barrels per day for the productioii of synthetic liquid fuels from coal by way of synthesis gas (carbon monoxide and hydrogen) has been constructed a t Louisiana, Rlo. The greatest attention is being given to the completion of a method for the production of synthesis gas by gasifying pulverized coal in the presence of steam and oxygen under pressure of 450 pounds per square inch. The 1950 literature of the Fischer-Tropsch process is presented under several subheadings in order to group and discuss similar references and to aid evaluation of the data. CATALYSTS
The catalysts proposed for thc conversion of synthesis gas to liquid hydrocarbons and oxygenated compounds are of the iron and cobalt type with various promoters, supports, and methods of preparation. Compounds of fluorine are used as promoters for iron catalysts. A reduced form of iron oxide promoted with metal fluoborates, including sodium fluoborate and especially potassium fluoborate, favors polymerization of olefins t o form olefinic hydrocarbons boiling in the gasoline range (166). A catalyst (123) prepared by the fusion of 33 moles of ferroferric oxide with one mole of ferric fluoride was effective a t 300 pounds per square inch and 500" F. A fluidizable iron catalyst (166)promoted by alkali was made by mixing finely ground iron oxide with potassium fluoride solution and drying. Four catalysts of the Fischer-Tropsch type were prepared by sintering iron or iron oxide. Spherical particles (161) were produced without agglomeration by passing an iron-type catalyst through the flame of an oxygen torch. A preferred iron-type catalyst (68)may be prepared by decomposing iron carbonyl to iron powder, promoting with alkali and alumina, pelleting the mix, sintering the pellets a t 843" t o 899" C. and finally reducing a t about 843" C. An improved catalyst (60) is obtained by subjecting iron oxides of any origin to a sintering treatment a t 1200" to 1W0F. Fines from a fluidized iron catalyst (80) are agglomerated to a size suitable for fluid catalytic operation (50 to 2 0 0 ~ by ) sintering a t 1300' t o 2000" F. and simultaneously burning off the carbon. Synthesis products (167) unusually rich in oxygenated compounds are obtained with an alkali promoted iron powder oxidized in a fluidized condition with air a t 371 " C. t o an oxygen content of 4 to 5% and reduced a t 371" C. Mill or bloom scale (162) formed when steel is rolled above 1oOO" to 1300" C. is processed into a very stable catalyst by grinding to about 100 mesh, impregnating with potassium carbon. ate and reducing a t 600" to 800" F. for 48 to 72 hours. This catalyst does not become sticky and defluidize or lose its initial density. Stainless steel (86)in finely divided particle size containing 4 to 3oY0 chromium and 4 to 8% nickel, activated by a small amount of a sodium compound, is used as a catalyst. A hydrocarbonsynthesis catalyst (22)is formed by spraying molten iron, cobalt, or nickel, containing a small amount of an activating material, onto spherical particles of aluminum in a reducing atmosphere, An improved synthesis catalyst (61) of iron, cobalt, or nickel is obtained from a carrier containing 5 t o 30% silicates. A very active catalyst (IS), highly resistant to attrition, is prepared by impregnating a gelatinous silicon dioxide hydrogel with the nitrates or other suitable salts of iron, cobalt, nickel, thorium, magnesium, etc. The formation and molecular weight of paraffin
Vol. 43, No. 9
wax (99) is controlled t o some degree with a catalyst containing less than 2y0 alkali silicate and 5 to 3Oy0 of the metal of the iron group present as silicate. Molybdenum disulfide (140) promoted with minor proportions of an alkali is an active catalyst for hydrogenation of oxides of cnrbon and for Synthesis of normally liquid hydrocarbons. Liquid hydrocarbons (46) are synthesized with a titanium boride catalyst a t 260° to 390" C. and an atmosphere to 500 pounds per square inchpressure. Fiveper cent of K4SbzOr(139)activatesferroferric oxide for synthesis. Another iron catalyst (138) contains five parts of an alkali-metal ferrate to 75 parts of ferroferric oxide. A Fischer-Tropsch catalyst (6) of greatly increased activity, which appears to resist oxidation and deposition of free carbon and to have greater stability and life, results from the conversion of the iron in a reduced synthetic-ammonia type catalyst to iron nitride by treatment with ammonia. A spinel type of compound formed from ferric oxide and an equimolar quantity of oxides of metals, such as magnesium, manganese, cadmium, zinc, alkali earths, beryllium, and chromium is superior to ferric oxide alone (156). An active catalyst (96,96) was prepared by igniting two parts of finely divided iron and three parts of alkali metal nitrate and heating the product at approximately 538" C. in an oxygrii-free atmosphere for about four hours before reduction. Several cobalt catalysts for the Fischer-Tropsch reaction zere prepared and investigated. A catalyst 23% more effective in hydrocarbon synthesis (126)than the usual thoria-promoted catalyst is composed of 32% cobalt promoted by 0.5 to 10% lanthanum oxide and 3% magnesia and supported on uncalcined diatomaceous earth. A similar catalyst ( 1 2 7 ) is composed of 32y0 cobalt promoted by 1% thoria and 3'35 magnesia on a dual support consisting of equal weights of uncalcined diatomaceous earth and alumina containing leas than 0.8% of alkali metal compound and stabilized with about 5y0 silica. Catalysts (56) having the composition: cobalt, 100; thorium dioxide, 6; magnesium oxide, 12; kieselguhr, 200 are the most active when reduced a t 400" C. in pure dry hydrogen. Hydrosilicate formation appreciably decreases the ease of reduction. Along with the x-ray data the diminution of surface area suggested that appreciable agglomeration of cobalt occurred during use of the catalyst. A nickel-aluminum oxide-kieselguhh catalyst (149) was shown to contain nickel aluminate and nickel silicate after being heated t o 450" C. The aluminate is active in synthesizing higher hydrocarbons; the silicate forms methane primarily. The distance between the nickel atoms in these two compounds is believed to be the factor responsible for the specificity of their catalytic properties. Several copper activated cobalt catalysts (121) were studied a t atmospheric pressure and 175" to 300" C. Alkalizing with potassium carbonate or potassium phosphate appeared to act as a selective poison of active centers for methane formation. Small additions of cerium oxide were very effective in increasing catalyst life and stability. Another catalyst stabilized by copper oxide (14) was composed of iron or cobalt alone or in combination with nickel, molybdenum, thorium, etc., supported on a base promoted by potassium hydroxide, potassium carbonate, etc. A series of articles by the Japanese (66, 68-70, 72-74) describes supported promoted iron catalyst for syuthesis of hydrocarbons. Using various supports, the oil yield decreased in this order: kaolin > active earth > acid earth > bentonite. Promoters studied were copper, potassium carbonate, and boric acid. REGENERATION
Three patents have been issued on methods of regeneration. A fluidizable catalyst (63)which has been contaminated with oily and waxy material is regenerated by destructive hydrogenation followed by treatment with a wash solvent. The hydrogenation conditions for an iron type catalyst are temperature in the range 232" to 399" C . and a pressure up to 750 pounds per square
September 1951
INDUSTRIAL AND E N G I N E E R I N G C H E M I S T R Y
inch; for a cobalt type catalyst, a temperature in the range 182" to 260" C. and a pressure up to 300 pounds per square inch. The carbon content ( 7 9 )of an iron catalyst is reduced from 3570 to about 5 weight % by contact n i t h 2 pounds of ferric oxide per pound of deactivated catalv-t a t G49" to 760' C. An iron-type svntheqis catalyst is regenerated (91) in a threestage process by heating M ith eithcr stram or carbon dioxide hetv, een 260' and 593' C., treating in an oxidizing atmosphere so as to oxidize the iron in prefeieiice to the carbon on the catalyst and finally burning the carbon off the catalyst with a gas contnining free ovygen between 371" and 700' C. without substantial further ovidation of the catalyst. REACTOR DESIGN
The apparntus and process ( 2 4 ) are described for convr:,tiiig synthesis gas to hydrocarbon mixtures of various boiling ixrigw. A rotating helix (224) is used to keep the catalyst i n suspmsioii. The catalyst (111) is arranged on the surface of vertical perforated tubes by extruding an aqueous slurry of the c a t d y s t i n the shape of a thin cylindrical sheath which slides direet,ly over the reactor tubes. The cooling fluid is circulated through the interior of the tubes and can also he applied to the catalyst surface to act as a solvent for wax formed on the catalyst. In one rract>or(2.5)vertical cooling coils have expanded sections arranged to reetrict the cross-sectional area of the reactor and thereby increase fluidization and heat transfer. I n another reactor (10) the bundles are partly submerged in the fluid catalyst bed so that no portion of the latter is more than 2 t o 4 feet, from the cooling medium. COMBINATIQN AND MULTISTAGE PROCESSES
A tm-o Lone system was studied (21) in which metal carbonyla formed in the first zone at 150' to 400" F. and 150 to 200 pounds per square inch were decomposed on a ratalvst carrier or spent catalyst in a secondary reaction zone. When a substantial amount of metal has accumulnted in the first zone, the flow of reactant? i,. reversed. Minimum cooling requirements are obtained (126) by passing the synthesis gas successively through four different catalvst beds with optimum operating temperatures progressively increased. The use of four 5-foot catalyst zones ( 6 4 ) connected in series gave complete control of the synthesis process and eliminated any irregularities in deepbed catalyst operations bv introducing successive increments of 'reactants into the separate independently supported catalyst masses. A two-reactor system (61) consistE of an isoparaffin synthesis catalyst in the first reactor and a doubly promoted iron catalyst in the second reactor; part of thc carbon dioxide formed in the first reactor is reduced to caibon monoxide in the second reactor and formation of additional carbon diovide is suppressed. In another two-chamber process ( 3 8 ) the first chamber was maintained a t 575" F. and the second a t 825' F. In another two-stage process a t a higher temperature ( I % ) , the first stage operates a t 600" F. and a louer hvdrogen to caibon monoxide ratio than is employed i n the wcond stage a t 700" F This has the effect of reducing the carbon rontent o f the catalyst and of converting a considerable quantity of caibon dio\ide to hydrocarbon and water by n-ay of the xvater-gas shift. A product containing a substantial amount of a high melting wa\ (58) is made by contacting a gas containing three to seven parts of hvdrogen to one part of carbon monoxide in a second zone with a catalvst pai ticle slurry obtained from the product stream of the first zone. In a two-bed system (199)a portion of the catalyst ie continuously led from the synthesis zone t o the hydrogenation zone in whi( h it is reduced with hydrogen and returned to the synthwiq zone. In a combination prore- ( 1 1 2 ) part of the synthesis gas is produced from carbon diovide ant1 light hydrocarbons made in the s\-nthe+ Tn order to utilize the endothermic dehydrogenation
1981
reaction (8) for the contiol of the exothermic hydrogenation of carbon monoxide, synthesis is carried out simultaneousl) with the dehydrogenation of naphthenes. T o make diolefins and a refined Fischer-Tropsch gasoline (RS), the raw gasoline is treated over a suitable catalyst t o remove organically combined oxygen and to isomerize the olefins, and the oxygenated chemicals separated from the aqueous phase are converted into diolefins by reacting them with a suitable catalyst. CARBON DIOXIDE IN FEED GAS
In the synthesis of hydrorarbons over an iron catalyst from a mixture of synthesis gas substantially free of carbon dioxide, a portion of the carbon monoxide is converted t o carbon dioxide {rith a corresponding loss of hydrocarbon yield. Several inveetigators have minimized or controlled the formation of carbon dioxide by limiting the composition of the synthesis gas. By hydrogenating carbon monoxide over a fluidized iron catalyst (48)the yield is increased and the formation of carbon dioxide is suppressed by the presence of a t least 15% carbon dioxide by using little or no water vapor a s well as a high ratio of hydrogen to carbon monoxide in the feed, and by limiting the conversion so t h a t some carbon monoxide remains in the effluent stream. The net production of carbon dioxide from the reaction zone is substantially reduced ( I N ) by controlling the quantity of carbon dioxide in the synthesis gas so that the ratio of the moles of bydrogen to the moles of carbon dioxide plus carbon monoxide is in the range of 0.6 to 1.0. ConverPion of substantially all the feed carbon monoxide into desircd products (144) is accomplished by bringing the feed mixt,ure consisting of carbon monoxide, hydrogen, water, and carbon dioxide in contact with a fluidized mixture of synthesis gas containing an iron catalyst toget,her with discrete particles of water-gas-shift catalyst, a t a reaction temperature of 288" to 371' @. In the synthesis of hydrocarbons over a fluidized iron catalyst (13W),carbon dioxide is included in the feed gas, and the mole ratio of hydrogen to carbon monovide is kept a t not less than 3 t o I , preferably a t 4 to 6 to 1. The concentration of carbon dioxide is adjusted so t h a t H2 - @ 0 2 / C 0 CO2 is 1.5 to 2 . Carbon deposition on the catalyst is minimized, qonversion t o liquid hydrocarbons is increased, and the total conversion i s increased. One experimenter ( 7 1 ) found t h a t 16% of carbon dioxide added to 1: 1 synthesis gas decreases the oil yield, but 6% carbon dioxide does not.
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FUNDAMENTAL STUDIES
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The fundamental Fischer-Tropsch reaction: CO 2H: -, HSO at 1atmosphere and 6 t o 21 atmospherespressure in the temperature region between 160" and 186' C. is discussed (18). Theenergyof artivationwas 31 kg.-cal.per mole a t pressures up to 10 atmospheres and 28 kg.-cal. per mole a t 1 atmosphere. In place of Fischer's carbide theory, a working hypothesis (7'6)based on chemisorption concepts for the mechanism of carbon monoxide hydrogenation is presented. This work ('77) deals with the formation and properties of ferrous carbide, Fischer's carbide theory of hydrogenation of carbon monoxide, and the effect of alkali and copper promoters on carbide formation. Formation of carbides and synthesis are parallel rather than successive reactions. Alkali catalyzes both reactions directly while copper does it indirectly through accelerating the reduction of ferric oxide. Chemical and magnetochemical investigations (104) of iron catalysts used in Fischer-Tropsch synthesis are reported. Two iron carbides, both having the formula Fe&, appear in various stages in the preparation and use of iron catalysts for hydrocarbon synthesis. By adding (67) potassium carbonate to a catalyst composed of 100 parts iron, 26 copper, two mangancse, and 125 kieselguhr, activated adsorption of carbon monoxide above 200' C. is inereased,
(-CH?-)
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1982
INDUSTRIAL AND ENGINEERING CHEMISTRY
while that of hydrogen is not, especially when 6% potassium carbonate is added. By adding boric acid t o the same catalyst, adsorptio,n of carbon monoxide is decreased and that of hydrogen increased a t 200' C. Investigation* ( 1 9 ) of the structure of the pore system indicate that the temperature region of the Fischer-Tropsch synthesis corresponds to that of beginning chemisorption. The heats of adsorption of carbon monoxide and hydrogen are calculated from the adsorption isotherms. Thermomagnetic studies (92) of iron catalysts indicate that copper addition affects the oxidation of iron during drying. When iron oxide is formed from ferric chloride, the addition of copper causes the formation of a ferric oxide in contrast to y ferric oxide without copper. From an investigation of nickel catalysts (94) an intimate relationship was found between the catalytic activity and the crystal &e. Under certain conditions of catalysis, the nickel in the catalyst was transformed into a paramagnetic hexagonal carbide. The Fischer-Tropsch synthesis ( 5 )was studied on a pelleted catalyst composed of 100 parts of cobalt, 18 thorium dioxide, and 100 kieselguhr in a fixed-bed reactor a t atmospheric pressure and 186' to 207' C. Craxford's postulate, that synthesis occurs on cobaltous chloride with secondary reactions on cobalt atoms, does not appear adequate t o explain the data reported. The kinetics of desorption of hydrogen, carbon monoxide, carbon dioxide, and methane from a nickel-aluminum-manganesekieselguhr catalyst (33) reduced in hydrogen a t 475' C. was measured. The reduction of a catalyst (103) containing nickel and small amounts of manganese and aluminum on kieselguhr was studied a t 120', 225O, 360', and 450' C. by noting the amounts of water, carbon dioxide, and methane evolved. The results (148) of an x-ray diffraction study of nickel, aluminum, and manganese on kieselguhr were summarized. MISCELLANEOUS
A general discussion ( 4 ) compares the characteristics of the catalysts for the Fischer-Tropsch synthesis in regard t o the composition and properties of the reaction product. A method (129) for decreasing carbon build-up on the catalyst and controlling the temperature during the start of the reaction cycle consists of purging the reduced catalyst with methane and then gradually replacing the flow of methane with synthesis gas. Severely deactivated silica-alumina cracking catalysts (137) were superior to bauxite for upgrading Fischer-Tropsch gasoline. Another patent ( 1 3 4 ) claims a process for dehydrating the oxygenated hydrocarbons in the gasoline over the oxides of thallium, aluminum, tungsten, and chromium without altering substantially the structure of the hydrocarbons produced. The yield of waxes (47) is increased by passing a synthesis gas containing 42 t o 70% of an inert diluent over a cobalt-thorium dioxide-kieselguhr catalyst a t 175' to225' C., 5 t o 15 atmospheres, and 100 to 200 volumes per volume of catalyst per hour. The yield of fatty acids (168) from hydrocarbon synthesis is increased without excessive deposition of carbon by maintaining a high concentration of carbon dioxide (300/0)and a high hydrogen partial pressure of about 175 pounds per square inch. Best results are obtained (131) by using fluid catalysts in hydrocarbon synthesis if the catalyst size distribution is: 0 to 2 0 ~ , 5 to 25%; 20 to 8Op, 30 to 85%; and above 80p, 5 to 3570. The deterioration (37) of the catalyst is reduced by removal of the oxygenated compounds that are made during synthesis and are in the uncondensed gas that is recycled to the reaction zone. By a process ( 2 7 ) which may be simultaneous polymerization and alkylation, the yield of liquid hydrocarbons is increased by introducing into the synthesis zone a recycle olefin fraction. Differences (10)in the European and Hydrocol Fischer-Tropsch processes are discussed. I n general Hydrocol gasoline is lower hoiling and more olefinic. D a t a for the isosynthesis (106, 106) are given on the catalyst
Vol. 43, No. 9
development, the effect of temperature and pressure of operation, and the composition of the reaction products. The addition of ammonia (39) to synthesis gas flowing over a cobalt catalyst resulted in a marked decrease of the yield of higher hydrocarbons without any increase in the amount of methane; amines were not formed. The injection of steam (146) into the synthesis reactor reduces carbon formation and minimizes catalyst degradation. A substantial portion of the exothermic heat of synthesis reaction is absorbed by adding water (108)or alcohols (26) to the synthesis gas passing through the catalyst bed. The reaction temperature (64) is controlled by passing synthesis gas through a fluidized mass of metallic iron catalyst which contains a heat transfer agent for cooling. Solid hydrocarbons are formed ( 7 5 ) by chain lengthening when higher liquid aliphatic hydrocarbons are introduced into the Fischer-Tropsch synthesis, The rate of the chain lengthening i p dependent upon the characteristics of the catalyst.
BUREAU OF MINES RESEARCH A N D DEVELOPMENT In pilot plant operation a t Bruceton, Pa. (164),fixed-bed experiments carried out by use of an oil-circulation process with a submerged catalyst bed were terminated in favor of the movingcatalyst bed. Smaller catalyst particles-Le., 10- to 40-mesh instead of 6- to 10-mesh-were used for moving-bed operation, and the linear velocity of the cooling oil was increased t o such a degree that the catalyst bed expanded until the bed height was about 25 to 35% greater than its settled height. A moving bed of synthetic-ammonia type catalyst was operated successfully in this manner for several months without increase in the pressure drop across the catalyst and entirely without cementation of the bed. I n laboratory scale experiments, nitrided iron catalysts have shown significantly greater activity and life than corresponding reduced catalysts. The products from the nitrided catalysts are very different from those obtained with reduced catalysts. The nitrogen is only very slowly removed from the catalyst during synthesis; available data indicate that carbon replaces the nitrogen and the ratio of total carbon plus nitrogen to iron atoms remains approximately constant. Nitrided catalysts appear to resist oxidation and deposition of free carbon in the synthesis. The Bureau of Mines has constructed a fixed-bed unit designed to operate at' pressures up to 5000 pounds per square inch. The unit will be used primarily to investigate the effectsof pressure on reaction rate and product distribution.
OIL AND FAT HARDENIN6 The technology of oil and fat hardening to obtain the desired characteristics in oleo or shortening is concerned with both the selective hydrogenation of fatty acid radicals containing more than one double bond and the control of the formation of iso-oleic acid. Kinetic studies are used to explain the different reactions which occur simultaneously and consecutively in the hydrogenation of an oil containing linolenic, linoleic, isolinoleic, and oleic acids. Such a kinetic study (9) has shown that the reactivity of the different acids was by no means determined by the total degree of unsaturation but depended in any case upon the position as well as the number of double bonds. Furthermore, by operating under conditions conducive to increased "selectivity" i t wa8 not possible to increase materially the differences in reactivities among all the unsaturated acids b u t merely between two groups of acids, comprising linolenic and linoleic on the one hand, and isolinoleic and oleic on the other. A study of the data (9) on the hydrogenation of cottonseed oil reveals that the ratio of the hydrogenation rate of linoleic acid t o the rate of oleic acid varies from about four t o one in very nonselective t o about 50 t o one in very selective hydrogenation. Analytical data on two series of linseed oils hydrogenated sclcc-
September 1951
INDUSTRIAL AND ENGINEERING CHEMISTRY
t i d y arid nonselectively showed on re-examination that in the nonselective hydrogenation of the oil, 24% of the linolenic acid reacting went t o linoleic acid, 6570 to isolinoleic acid, and 11% directly t o oleic acid. I n the selective hydrogenation the corrcisponding figures were: none to linoleic acid, 54% t o isolinoleir acid, and 46% t o oleic acid. The behavior of soybean oil hydrogenated selectivity was quite similar to that, of linseed oil. The results indicate t h a t the solution of hydrogen in the oil and the adsorption of unsaturatrd oil on the catalyst are the tn-o steps which control the reaction rate. It is suggested that hydrogen pressure, degree of hydrogen dispersion through the oil, catnlyst concentration, and temperature, all affect the selectivity of t,he reaction through their influenre on the concentration of hydrogen in the reaction zone, with selectivity being favored by a low concentration. A rate study on the hydrogenation (150) of a niixturc of oleic acid agd its methyl ester showed a rrm:wkable selective hydrogenation of the acid. The ratio of the reaction rat,e constants was 2.8. In the homologous series, such as methyl, ethyl, etc., the rate of ester hydrogenation decreases with increasing molecular weight. The kinetics ( 17 0 ) of the hydrogenation of sunflower oil composed of 41.4y0 of oleic acid and 48.7% of linoleic acid with a nickel catalyst was studied a t tempcmtures ranging from 169' to 210" C. The ratio of the reaction rat,e of linoleic to that of oleic acid falh with rising temperature. This shows t h a t with temperature t h e rate of hydrogenation of oleic acid increases faster than the rate of linoleic acid. When finback whale oil is hydrogenated catalytically (119) with a nickel-silica gel catalyst till the product gives an iodine number of 83, only those fatty acid radicals having two or more double bonds are saturated; those with one double bond originally existing in the oil or formed by this partial hydrogenation remain unsaturated. The reaction is the same a t 180' or 210" 6 . but it proceeds 1.44 times faster at210' C. Improved selectivity ( 1I O ) , faster hyc sgenation, and lower trans-acid formation than t h a t obtainable during ordinary hydrogenation resulted from the hydrogenation of polyethylenic acidcontaining oils in the presence of solvents. Four reviews ( 7 , 8 5 , 4 9 , 88) on oil and fat hardening have been published in other countries. An article published in Great Britain ( 7 ) revien-s current practices in refining and hardening technology with reference to methods and equipment used in the United States, Germany, and Great Britain. Conclusions on process variables are essentially the same as those current in the Cnited States: selectivity and formation of iso-oleic acids are favored by relatively high temperatures, B O " C. and over; increased concentration of catalyst, 0.1% nickel or higher; and low hydrogen pressure, 5 to 10 pounds per square inch. -4series of articles published in Japan (120)reports the preparation and use. of Adkins' copper chromite catalyst and of copper and chromium catalyst for the hydrogenation of finback whale oil and soybean oil. Unsaturated fatty acids above the linoleic acid series in both oils undergo selective partial hydrogenation a t 180" or 210' C. under atmospheric pressure or a t 140' C. under 40 pounds per square inch. At 180" C. and 40 pounds per square inch, however, oleic acid is reduced x i t h both the acid radicals and the double bonds undergoing hydrogenation.
HYDROGENATION OF ACETYLENE The increasing demand for ethylene-an important intermediate in synthetic rubber, chemicals, resins, and aviation alkylate -has focused attention upon the removal of acetylene and related compounds by selective hydrogenation from gas streams containing ethylene, usually made by the thermal cracking of ethane, propane, or butane. The selective hydrogenation process is athractive economically because the raw ethylene stream normally contains sufficient hydrogen t o saturate acetylene. A proreps is discloscd in a pntrnt (11) for the selective hydro-
1983
genation of acetylenic compounds in the prewence of olefins using it catalyst containing partially sulfided reduced nickel oxide. A gat; containing 2y0 acetylene, 30% ethylene, 25% hydrogen, and 437, methane, nitrogen, and other diluent gases is passed over a partially sulfided nickel-alumina catalyst. The space velocity is varied between 1000 and 3000, the temperature and pressure a t the outset of the run are 150' C. and 20 pounds per square inch, During the course of the run, the temperature and pressure are gradually raised in stepwise fashion so that a t the end of IO00 hours, the temperature is 300' C. and the pressure is 40 pounds per square inch. The acetylene removal throughout the run averages better than 9970. The exit gas analyses showed 29.8Y0 ethylene and 0.00970 acetylene. A nickel-chrome catalyst, developed by the Germans 2nd tested by the British, is reported (16) to hydrogenatc acetylene selectively in the presence of ethylene. When the hydrogen concentration is in excess of 470, small amounts of acetylene impurity, such as 0.5 to 1.0'%, can be preferentially hydrogenated without affecting the ethylene. The optinium temperature for selectivc hydrogenation is dependent upon the concentration of hydrogen in the gas st,ream. K i t h 12y0 hydrogen in k gas stream produced by the vapor-phase pyrolysis of kerosene, the optimum conditions for selective hydrogenation were a temperature of ,725" C. and a space velocity of 350 volumes a t standard temperature and pres-. sure (S.T.P.) per volume of catalyst per hour. A t 260" C., other conditions being maintained, breakthrough of acetylene was definite. When the hydrogen concentration of the kerosene cracker gas was changed to 4% and acetylene to O.5YOby adding the requisite amount of acetylene and ethylene, the optimum temperatare for complete removal of acetylene xa8 400" C. with a throughput of 300 volumes S.T.P. per volume of catalyst per hour. Acetylene has been hydrogenated selectively to ethylene in countries where natural gas is scarce. The Germnnlj hydrogenated acet,ylene to ethylene during the war over a palladium on silica-gel catalyst with a yield of 92 to 947,. I n J s p n ( 9 7 )acetylene mixed with a n equal volume of hydrogen was hydrogenated t o ethylene at 40' 6.over a cat,alyst of magnesium oxide, manganese oxide, zinc oxide, elironlie oxide;, or aluminum oxide singly or in combination, supported on mid clay and mixed with 1 per 40 t o 1400 parts of barium chloride. The ethylene yield was 90 to 93%. Another catalyst (128) c o m p e d of a copper strip containing 13y0 copper oxide t h a t TVW electroplated with 0.007 part of nickel yielded 81% ethylene at 130" C. The yield from a third catalyst operating a t 140" C. was 83y0 ethylenc ( 6 3 ) . The catalyst composition was one part palladium, one bismuth, and 100 kieaelguhr.
AMMONIA SYNTHESIS Although the synthesis of ammonia is a fairly old process, new plants are still being constructed in the United States and this expansion is expected t o continue. A combination process (65) is described for t,he production of both ammonia and hydrocarbons over the same catalyst. The catalyst is an iron powder containing small amounts of sulfur, aluminum oxide, and potassium oxide as promoters. It, is first used in a dense fluid-phase converter for ammonia synthesis from nitrogen and hydrogen a t 160 to 400 atmospheres. Conversion per pass is at least twice that obtained with a static catalyst bed. A portion of this catalyst is withdrawn and added t o a similar fluidized system where carbon monoside is hydrogenated. A portion of the catalyst is withdrawn from this last stage, regenerated and returned to the ammonia converter. It is reported (167) that the synthesi.s of ammonia from hydrogen and nitrogen is promoted by subjecting the gases to ultrasonic vibrations of a frequency between 30,000 and 50,000 cycles per second in the presence of a finely divided promoted iron catalyst suspended in the gas stream a t temperatures between 100" and 200" C. and pressures not esceeding 10 atniosphercs. At a frequcwcy of 40,000 r).clrs p r r wrond, 150' C . . 1.5 to 2 atnios-
1984
I N D U S T R I A L A N D E N G I N E E R I N G CHEMISTRY
pheres and 100 pounds of catalyst to IO00 cubic feet of gas, the yield of ammonia is 2970 per pass. A catalyst (100) composed of a mixture of iron, nickel, or cobalt with magnesium or vanadium is activated with a stream of nitrogen a t 350" to 400" C. and 2 kg. per square cm. pressure for 24 hours. A yield of O.6Y0 ammonia was obtained over this catalyst at a temperature of 300" C. and a pressure of 1 kg. per square cm. and a yield of 117 0 was obtained by increasing the pressure t o 50 kg. per square em. The activation of nitrogen by iron and nickel catalysts was studied (59) by treating the catalyst with hydrogen cyanide for 30 minutes, removing the residual gas, adding varying amounts of hydrogen a t continually increasing temperatures and analyzing the equilibrium mixtures. As the temperature of this nickel complex is raised, ammonia decreases and methane increases. When iron is used at 162' C., the optimum amount of ammonia is 33% after 0.5 hour with a gas mixture containing 62y0hydrogen; above 162' C. ammonia decreases and methane appears a t 330' C. The utiliaation of a synthetic ammonia plant for the production of methanol is described (102).
HYDROGENATION OF PETROLEUM Hydrogenation reactions of interest to the petroleum industry are saturation of ole& double bonds for production of aviation gasoline, hydrogenation of aromatics in ~ a t a l y t i ccycle stock, and destructive hydrogenation of gas oils. In a mixed liquid and vapor phase operation (130)yields of above 90% of hydrotrimer were obtained by hydrogenating triisobutylene a t 400" t o 500' F. over a charcoal catalyst impregnated with a reduced metal oxide from Group VI or VI11 of the periodic &able and saturated with hydrogen sulfide at 600" to 900' F. Inclusion of 0.8 t o 2y0 hydrogen sulfide with the hydrogen feed during a run prevents catalyst inactivation. Hydrogemtion of olefins and sulfur compounds (32)for the improvement of rich-mixture ratings of aviation gasoline in several catalytically @racked gasolines over a tungsten-nickel sulfide catalyst was studied on a pilot plant scale. Typical operating conditions were: pressure, 720 pounds per square inch: mole ratio of hydrogen t o feed, 7 : 1: liquid hourly space velocity, 10; temperature, 850" F. At constant operating conditions sulfur retention is independent of sulfur content of feed. Sulfur compounds are hydrogenated more readily than olefins, and olefins more readily than aromatics. When the bromine number of the product is not below three, loss of aromatic compounds is negligible, and a b the usual level of five t o ten, diolefins are completely hydrogenated. T h e activity of a hydrocracking catalyst containing 7% nickel on a hydrofluoric acid-treated Super Filtrol support is excellent after heating for 6 hours a t 850' F. but is reduced after heating at 1200' F. (159). T h e hydrogenation of cycle stocks from catalytic cracking of gas oils at 3000 pounds per square inch t o complete saturation and at 750 pounds per square inch t o partial saturation with a sulfur resistant catalyst is described (168). Hydrogenation converta some condensed ring aromatics t o single-ring compounds and gives vh%ually complete sulfur removal. Results of catalytic cracking testa show that the saturated product is equal in crackability to the virgin feed. Mineral oils were hydrogenated at 250 atmospheres pressure and 350' ta 400' C. over compressed tungsten disulfide tablets and a compressed mixture of tungsten disulfide and nickel sulfide on activated clay (113). Increasing the catalyst density by increased tablet compression gave a n increased space-time yield which waa proportional t o the increased weight of active catalyst material in the same reaction volume. When t h e tablet size was decreased, an unexpected lowering of the reaction temperature was noted with a corresponding increase of the reaction velocity.
Vol. 43, No. 9
The preparation and physical chemical d a t a of tungsten disulfide catalysts are discussed (107). Hydrogen and unsaturated hydrocarbons are very strongly adsorbed on tungsten disulfide and the hydrogenation of olefins is active above 200' C. Hydrogenation of aromatic compounds and osygen, nitrogen, arid sulfur compounds on tungsten disulfide requires 300' to 400" C. T o avoid cracking reactions tungsten disulfide or molybdenum disulfide is modified with small amounts of nickel sulfide deposited on activated alumina. Above 450" C. even alumina base catalysts cause cracking which can be suppressed by the addition of basic oxides such as zinc oxide and magnesium oside.
MISCELLANEOUS Raney nickel catalysts are used for many other hydrogrnatione besides the hardening of fats and oils Primary amines are prepared from nitriles by hydrogenation a t pressures of 55 to 95 kg. per square cm. with yields of approximately 90% ( 9 3 ) . The use of noble metals as hydrogenation catalysts in acid solutions for the preparation of amino alcohols from Mannirh bases is described (167). The general effects of.the promoter artion of platinic chloride on W-6 Raney nickel are reported (87). Details are given of the preparation of the W-6 catalyst ( 1 5 ) . New studies on Raney nickel and hydrogenation of a-,&unsaturated kctones are described ($4). T h e activity of the catalysb is depentlent upon their nickel content. Reproducible catalysts of high activity were prepared. Copper-chromium oxide catalysts are used extensively for the hydrogenation of fats and oils to alcohols and for the reduction of aldehydes, ketones, and nitrocompounds. T h e catalysts used for t.he hydrogenation of fats and oils to alcohols a t high temperature and pressure consist mainly of cupric oxide and chromic oxide, with the addition of 0.3 t o 0.5y0of oxides, hydroxides, carbonates, or soaps of alkali or alkaline earth metals (145). Another catalyst for the same reaction consists of 1 to 3 moles of chromium trioside and 1 t o 2 moles of a t least one acetate of a metal selected from zinc, copper, and cadmium heated at 95" to 300" C. ( 7 8 ) . Catalysts composed of nickel, cobalt, and copper precipitated with chromate and supported on a base of pumice, kieselguhr, asbestos, acid clay, bentonite, or active clay reduce aldehydes, ket,ones, nitrocompounds, and unsaturated hydrocarbons in the vapor phase at 1 atmosphere. The activity remained unchanged for one to three months (98). By increasing the ratio of chromium t o copper in a copper chromite catalyst, its activity wne enhanced for the reduction of methyl laurate and palmitate a t 6000 pounds per square inch gage and 100" C. ( 1 ) . Aldehyde9 and ketones were hydrogenated at room temperature and certain esters a t 80" C. over this catalyst. Reduced nickel catalysts are used in many hydrogenat,ion reactions. The nickel oxide is made by calcining the nitrnte, carbonate, or hydroxide. The activity of the catalyst is affected by the temperature of calcination and the suppol t . An active form of nickel oxide is prepared by heating nickel carbonate at 400' C. (43). Examination of this preparation by small-angle x-ray diffraction gave a particle radius of 27 A. Another x-ray diffraction study showed a continuous variation of the lattice t o 400"C. (44). There ivas no evidence of suboside formation. Under appropriate conditions nickel hydroxide forms t w o compounds with silica gel (160). T h e properties of these compounds are a determining factor for the activity of the catalysts prepared from them by reduction. -4 study of nickel catalysts by differential thermal analysis indicates hydrosilicate formn t ion a t 400" (147). Unbranched hydrocarbons containing one less carbr)n atom than the original fatty acid were made by hydrogmnting a fnt with a copper promoted nickel catalyst on kieselguhr under 200 atmospheres pressure and a t 250" t o 395' C. (60). Two Japanese articles discwss the recovery of spciit, nickrl c : i t : i lysts used for hydrogenatiilg oils (90,f5l).
c.
September 1951
INDUSTRIAL AND ENG INEERING CHEMISTRY
Reducednickel catalysts are stabilized to oxidation wit,h air by wetting with steam or water and drying in air to the desired water content (2). Several patents have been issued on catalysts of the foraminate type other than Raney nickel. A cobalt-alumina is disclosed (114). The activity of a copper-alumina-chromia catalyst is reported (86). A copper-silica catalyst is effective for hydrogenation, hydrogenolysis, dehydrogenation, and reductive amination (115). A nickel-silica catalyst is suitable for use in hydrogenation, hydrogenolysis, and reductive amination (If 6). Several publications on catalysts discuss the effect of palladium and platinum catalysts on the rate of hydrogenation of ethylene carboxylic acids, t h e catalytic hydrogenation of compounds containing a eaihonyl group and heterogeneous catalytic autoxidation of benzaldehyde (36). A kinetic study of the hydrogenation of ethylene over a coppermagnesia catalyst was made in a tubular flow reactor (169). The preparation of a nickel-zirconium catalyst which has a high activity, particularly in hydrogenation practice a t 60' t o 110" C., is disclosed (109). A finely divided porous nickel hydrogenation catalyst containing 0.5t o 3.5% chromium based on nickel content gives equal yields of products in a much shorter time than that, obtained with an equal weight of the usual catalyst, and the activit.y decreases more slowly (122). The kinetics of gas-phase and liquid-phase catalytic reactions are interpwted in terms of the relative adsorptions of reactants and products. Reactions over nickel catalysts include the hydrogenation of carbon monoxide and carbon dioxide t o methane, of benzene to cyclohexane in the presence of carbon dioxide, of acetone t o isopropyl alcohol, and of acetylene t o ethylene (62).
BIBLIOGRAPHY (1) .4dkins, H., Burgoyne, E. E., and Schneider, H. J., J . Am. Chea. SOC.,72, 2626-9 (1550). (2) Ahlberg, J. E., and Hiskey, C. F. (to Atomic Energy Com-
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1985
(30) Clark, E. L., Polipetz, X I . G . , Storch, H. K., Weller, S., and Schreiter, S., IND. ENG.CHEM., 42, 861-5 (1950). (31) Clarke, E. A,, Chaffee, C . C., and Hust, L. L., E. S. Bur. Mines. Reat. Invest. 4676 11950). (32) Cole, R. M:, and Davidson, D. D., IND.ENG.CHCY.,41, 2711-15 (1949). (33) Cornault, P., J . chim. phys., 47, 154-64 (1950). (34) Cornubert, R., and Philisse, J., C o m p l . rerid.. 229, 4613-2 (1949). (35) Craxford, S. R., and Poll, 1., .I. chim. phus., 47, 233-6 (1950). (36) Csuros, Z., and Gergely. Edith, Hung. A c t o I'him., 1, SO.4 / 5 , 1-26, 27-44, 45-84 (1949). (37) Dart, J. C. (to Standard Oil Development Po.!. U. S. Patent 2,497,932 (Feb. 21, 1950). (38) Diekinson, N. L. (to hI. W. Kellogg C'o.;, Ibid., 2,481,089 (Sept. 6, 1949). (39) Eidus, Ya. T., and Guseva, I. V.,Izrest. .-ik,rd. Xaufc, S S S R , Otdel. Khiin. iVaiak, 1950, 287-90. (40) Elliott, M. il., Kandiner, H. J., Kallenlxrger. R. H., Kiteshue, R.W-., and Storch, H. H., I s n . Esc.C ' I i E M . , 42, 83-91 (1950). (41) Falkum, E., and Glem, R. .4.,F7ael. 29. Yo 8. 178-84 (1950). (42) Foster, A . L., P e t r o l e i m Bngr., 23, Yo. 2. ('29-30 (1951). (43) Franpois, Jeannine, Covzpt. l e d . , 230, 1252---4 :1950). (44) Ibid., pp. 2183-4. (45) Frankenburg, W. G. (to Hydrocarbon Research. Inc.), U. 3. Patent 2,507,510 (May 15, 1950). (46) Frankenburg, W. G., aiid Layng. E. T., [ b i d . , 2,510,906 (June 6, 1950). (47) Friedman, A. H. (to Phillips Petroleum Co.), [ b i d . 2,500,533 (March 14, 1950). (48) Funasaka, W., Yokogawa, C., and hlatsuoka, S., J. Chem. SCIC. ( J a p a n ) , Ind. Chem. See., 51, 26-7 (1948). (49) Galan, Rodrigo Cota, I o n , 9,580-90 (1949). (50) Gillespie, B. 6. (to Standard Oil Deveiopnient C o . ) , r. S. Patent 2,496,343 Web. 7 , 1950). (51) Grahme, J. H. (to Texaco Development Corp.), 16~2..2,503,724 (April 11, 1950). (32) Grass, R. C., and Storch, €1. H., Chem. E U Q ..Vezds, 28, 046-8 (1950j . (53) Griffin, L. I., Jr. (to Standaid Oil Development eo.),U. S. Patent 2,487,867 (April 15, 1949). (54) Ibid., 2,498,838 (Feb. 28, 1950). (55) Guthrie, V. B., Petroletrm Processing, 5, 503-10 (1950). (56) Hagy, James L7. (to Stanolind Oil and Gas (Jo.1, C. S. Patent 2,493,454 (Jan. 3, 1950). (57) Hall, C. C., J . I n s t . Fuel, 23, 145-51 (19j0,. (58) Holden, C. H. (to Standard Oil Developrnent Co.). U. S. Patent 2,483,771 (Oct. 4,19401. (59) 'Hont, M . D., and Jungc~.s.J. C.,Bull. soc. chim. BeIges, 58, 450-9 (1949). (60) Hosman, B. E. b.. Steeiiis, J. Van, and Waterman, H. I., Rec. trav. chim., 68, 939-44 (1949). (61) Houtman, J. P. W.,Engel, W.F., and Hoog, €1. (to N.V. de Bataafsche, Petroleum Maatschappij), Dlutch Patent 64.T19 (Nov. 15, 1949). (62) Jungers, J. C., and Coussemant, I
