Process for the production of alcohols and diols

A process for the production of alcohols and diols by hydrogenation of a corresponding unsaturated organic compound selected from esters, diesters and lactones which comprises:

• (a) providing at least two hydrogenation zones, each containing a charge of a granular hydrogenation catalyst effective for catalysing the hydrogenation of the unsaturated organic compound to the alcohol or diol and selected from copper-containing and Group VIII metal-containing catalysts;
• (b) supplying to at least one of the hydrogenation zones, in a first phase of operation, a vaporous feed stream comprising a hydrogen-containing gas and an unsaturated organic compound selected from C.sub.1 to C.sub.4 alkyl esters of C.sub.8 to C.sub.22 alkylcarboxylic acids, di-(C.sub.1 to C.sub.4) alkyl diesters of C.sub.4 to C.sub.16 dicarboxylic acids, gamma-butyrolactone and epsilon-caprolactone;
• (c) maintaining the at least one hydrogenation zone, in the first phase of operation, at a temperature in the range of from about 150.degree. C. to about 350.degree. C. and a pressure in the range of from about 150 psia up to about 2000 psia;
• (d) recovering from the at least one hydrogenation zone, in the first phase of operation, a reaction product stream comprising the alcohol or diol;
• (e) supplying to at least one other hydrogenation zone, in the first phase of operation, a stream of hydrogen-containing gas thereby to reactivate the charge of hydrogenation catalyst selected from copper-containing and Group VIII metal-containing catalysts therein;
• (f) supplying to the at least one other hydrogenation zone, in a second phase of operation, a vaporous feed stream comprising a hydrogen-containing gas and the unsaturated organic compound;
• (g) maintaining the at least one other hydrogenation zone, in the second phase of operation, at a temperature in the range of from about 150.degree. C. to about 350.degree. C. and a pressure in the range of from about 150 psia up to about 2000 psia;
• (h) recovering from the at least one other hydrogenation zone, in the second phase of operation, a reaction product stream comprising the alcohol or diol;
• and
• (i) supplying to the at least one hydrogenation zone, in the second phase of operation, a stream of hydrogen-containing gas thereby to reactivate the charge of hydrogenation catalyst therein.