METHOD OF PRODUCING 1,5-PENTANEDIOL AND/OR 1,6-HEXANEDIOL

摘要

It is intended to provide a method of producing 1,6-hexanediol and/or 1,5-pentanediol by esterifying a carboxylic acid mixture comprising glutaric acid, adipic acid, 6-hydroxycaproic acid, etc., which is a by-product obtained in producing cyclohexanone by oxidizing cyclohexane with oxygen or an oxygen-containing gas, with an alcohol such as methanol, ethanol, butanol or 1,6-hexanediol and then hydrogenating the esterified products thus obtained in the presence of a copper-containing catalyst, wherein the degradation of the catalyst can be inhibited and thus 1,5-pentanediol and/or 1,6-hexanediol can be produced at a high yield, thereby establishing industrial advantages. This problem can be solved by hydrogenating the esterified products as described above with the use of a catalyst prepared by preliminarily reducing a copper-containing catalyst in an alcohol having an acid value (AV) of 0.5 mg KOH/g or less or an ester having an acid value (AV) of 0.5 mg KOH/g or less.