GB709225A - Improvements in or relating to an alcohol synthesis process - Google Patents

Abstract

Olefines, carbon monoxide and hydrogen are contacted in an initial carbonylation zone with a carbonylation catalyst to produce oxygenated reaction products comprising aldehydes which after removal of catalysts therefrom are hydrogenated in the presence of a hydrogenation catalyst, preferably a sulphactive catalyst, to produce alcohols, the products from the hydrogenation zone being distilled from higher boiling secondary reaction products to form a bottoms product and alcohols which are recovered and at least a portion of the bottoms product is recycled to the hydrogenation zone and additional amounts of alcohols thereby recovered. Molybdenum sulphide (cf. Specification 664,974) is a preferred hydrogenation catalyst. Water may be added to the carbonylation stage (cf. Specification 668,963) and also to the hydrogenation stage which is preferably effected in the presence of 3 to 10 per cent of water (cf. Specification 671,608). The quantity of recycle bottoms may vary from 5-50 per cent. In a diagrammatic illustration an olefine feed containing 1-3 per cent of a cobalt soap, e.g. the naphthenate or stearate, is treated with H2 and CO in the volume ratio of 0.5 to 2 at 225-450 DEG F. and 2000-4000 p.s.i.g. optionally with the addition of up to 10 per cent of water calculated on olefine feed. Carbonylation products are cooled, passed to a separator and unreacted gases preferably recycled. The liquid products may be in part recycled to the reactor (cf. Specification 647,363) and are subjected to temperatures of 200-400 DEG F. to deposit catalyst as metal optionally in the presence of hydrogen as a stripping gas, preferably at 15-200 p.s.i.g. Catalyst free products are hydrogenated in the presence of 10 per cent molybdenum sulphide on an activated carbon at 2500-4500 p.s.i.g. and 300-600 DEG F., preferably 2000-3500, especially 2800-3200 p.s.i.g. and 400-500 DEG F. and preferably in the presence of up to 50 per cent, especially 1-10 per cent, of water. Hydrogenation products are cooled and passed to a separator to remove hydrogen liquid products being distilled, optionally after removal of water, to remove unreacted olefines the residue being further distilled to provide alcohols and a bottoms product at least a portion of which is returned to the hydrogenation zone. Examples of the above process are provided using a C7 olefine as feed and Tables given to shown the increased yields of alcohols and aldehydes and decreased amounts of bottoms products over conventional methods of operation. Specification 671,833 also is referred to.