GB715465A - Improvements in or relating to catalytic conversion of oxygenated organic compound mixtures - Google Patents

Abstract

The proportion of alcohols and/or ketones in a dilute aqueous mixture thereof with aldehydes and acids, which mixture has been separated from the reaction products obtained in the catalytic synthesis of hydrocarbons from carbon monoxide and hydrogen, is increased by contacting with a catalyst of the same composition as that used in said hydrocarbon synthesis, in the presence of hydrogen, at about 15-100 p.s.i. and 125-175 DEG C. where an increase in ketones is desired or at 200 p.s.i. and above at 125-360 DEG C. where an increase in alcohols is desired. The feed should in general contain at least 5 per cent of the oxygenated compounds and 5 per cent water. The aqueous phase of the synthesis product which may be mixed with oxygenated compounds from the oil phase is a suitable feed. Vapour or liquid phase operation may be employed with fixed or fluidized catalysts. At low temperatures, 125-175 DEG C., and 200-600 p.s.i. or above, using 1 vol. H2 to 1 vol. feed, the alcohol content is increased at the expense of the aldehydes. At low temperatures and pressures, 125-175 DEG C. and 15-100 p.s.i., the ketone content is increased at the expense of alcohols, aldehydes, and acids. At high temperatures and pressures, 285-350 DEG C. and 200-600 p.s.i. or above, both alcohols and ketones are increased. The aqueous layer from a synthesis product is mixed with hydrogen in a saturator at from about 80 DEG C. at 15 p.s.i. to 212 DEG C. at 530 p.s.i. to give a vaporous mixture of about 50 per cent by weight of each. It is then reacted, using mill scale in fluidized form as catalyst, and an aqueous fraction separated which is fractionated to recover alcohols or ketones while the remainder is mixed with the original feed. In examples: (1) an aqueous phase from a hydrocarbon synthesis using a fluidized iron catalyst is treated with a similar catalyst and an equal volume of hydrogen at 150 DEG C. and 15 p.s.i. to give an increase in ketones, particularly acetone; (2) treatment is effected using a fixed catalyst in a batch operation at 125 DEG C. and 450 p.s.i. with a gain in ethanol; (3) treatment as in (1) but at 315 DEG C. and 450 p.s.i. gives a gain in ethanol and acetone; (4) treatment as in (1) but with a 4 : 1 ratio of hydrogen and at 315 DEG C. and 550 p.s.i. shows a gain in ethanol and acetone; (5) an aqueous mixture of acetic and higher fatty acids is treated at 315 DEG C. and 400 p.s.i., illustrating the conversion of acids to aldehydes and alcohols.