FR969735A - Process for manufacturing synthetic products from carbon monoxide, hydrogen and olefins - Google Patents

Abstract

Oxygen-containing organic compounds such as aldehydes are obtained by reacting carbon monoxide, hydrogen and olefines at elevated temperatures, e.g. 100-150 DEG C., and at pressures of at least 50 atmos. in the presence of a catalyst containing "cobalt" the catalyst being withdrawn from the reaction zone, hydrogenated at about 200 DEG C. and returned. By proceeding in this manner it is stated that catalytic activity is maintained at a high level. The term "cobalt" is defined as cobalt metal or cobalt compounds capable of reduction with hydrogen to cobalt metal or capable of forming cobalt carbonyl compounds by reaction with carbon monoxide. Hydrogenation is preferable effected at approx. 300-400 DEG C. and at atmospheric or superatmospheric pressure for at least 10 minutes, preferably 30-150 minutes. Catalysts specified are cobalt basic carbonate, naphthenate and fatty acid salts and a mixture of cobalt with thoria, magnesia and kieselguhr. Catalysts used are preferably powdered or in granular form. Cobalt removed from the reactor dissolved in reaction products may be separated by heating in the presence of hydrogen in the conventional fashion or when lower olefines, e.g. ethylene, p propylene and butylenes are used the product may be flash distilled giving aldehydes overhead and a bottom of high boiling products, the catalyst and any high boiling reaction medium used. In the latter case the bottoms may be hydrogenated at 250-400 DEG C. and passed to the reaction zone with or without removal of catalyst free liquid. The catalyst may be used in a fixed bed or in the mobile state as a solid or fluid. With fluid catalysts as described in Specification 702,192, cobalt after separation from reaction products is hydrogenated, converted to a fluid compound by treatment with a carbon monoxide containing gas and returned to the reaction zone. Shale spirit is a suitable feedstock. The reaction is preferably conducted in a continuous fashion. In an illustration olefinic feedstock mixed with powdered catalyst comprising metallic cobalt on pumice, kieselguhr or silica is pumped to a reactor at 100-200 atmos. and maintained at an elevated temperature. Water gas (fresh and recycled) is passed through the bottom of the reactor and out at the top where part is vented and part recycled so that the hydrogen content of recycled gas is kept below a CO-H2 ratio of about 1 : 2. The liquid product passes through a pressure let down valve to a gas separator where gas is vented and product and solid catalyst pass to a vessel kept partially filled with liquid where hydrogen is passed through at 100-120 DEG C. to decompose the cobalt carbonyl, solid catalyst is separated in a settler and part recycled to the reaction vessel and part regenerated together with fresh make-up catalyst by treatment with hydrogen at 300-400 DEG C. In examples, (1) Scottish shale spirit of B.R. 50-130 DEG C. containing 0.1 per cent. by weight of sulphur as organic sulphur compounds and 40 per cent. by weight of olefines is reacted with water gas at 145 atmos. and 140-160 DEG C. in the presence of metallic cobalt on kieselguhr powdered catalyst, where hydrogen absorption ceases, the reactor is cooled, pressure released and the products treated with hydrogen at 100-120 DEG C. for one hour when the liquid products were removed and found to be free of cobalt, successive batches of shale spirit are reacted on the same catalyst charge in a similar fashion and the fall in catalyst activity is illustrated by figures, (2) Scottish shale spirit B.R. 130-165 DEG C. containing 37 per cent. of olefines and 0.16 per cent. of organic sulphur compounds as sulphur is pumped downwards over a catalyst bed consisting of metallic cobalt on kieselguhr concurrently with water gas at 105 atmos. and 125-135 DEG C., the aldehyde-containing product is hydrogenated for 3 hours with Raney nickel at 120 atmos. and 150 DEG C. and the proportion of alcohols in the product determined so that the conversion of spirit to alcohol is calculated for 8 consecutive batches, at the end of the second and fifth the catalyst is removed from the reactor, treated with hydrogen at 380 DEG C. and atmospheric pressure and recycled, the effect of catalyst regeneration in terms of conversion being shown in a table, (3) is similar to (2) spirit of B.R. 50-108 DEG C. and of 49 per cent. olefine and 0.1 per cent. sulphur content is used, reaction effected at 140 DEG C. and 100 atmos. the products being hydrogenated as before and a similar table is provided, (4) propylene is fed at 0.3-0.4 vols. per vol. of catalyst per hour through the catalyst of (3) xylene being used as reaction medium at 1 vol. per vol. of catalyst per hour, reaction is effected at 100 atmos. and 140 DEG C. and the decline in aldehyde production with successive batches is shown in a table as also is the recovery when the catalyst is removed from the reactor and treated as in (2) before return to the reactor, and in (5) a Scottish shale spirit of B.R. 130-165 DEG C. is passed through the catalyst of (3) at 105 atmos. and 130 DEG C. at a feed rate of approx. 1-5 vols. of liquid feed per vol. of catalyst per hour and the fall in aldehyde production noted over a period of hours together with the advantageous use of a temperature of 400 DEG C. for regeneration as compared with one of 250 DEG C.