Patent ID: 8853465

Claim:
A process for preparing neopentyl glycol (NPG) by continuously hydrogenating hydroxypivalaldehyde (HPA) with hydrogen, in the liquid phase, in the presence of a hydrogenation catalyst, in a hydrogenation reactor, by combining an HPA-comprising stream with an NPG-comprising stream to give a hydrogenation feed and introducing the hydrogenation feed into the hydrogenation reactor and additionally supplying at least one pH regulator selected from the group consisting of tertiary amine, an inorganic base, an inorganic acid and an organic acid to the HPA-comprising stream or the NPG-comprising stream or the hydrogenation feed, in order to establish a pH of 7.0 to 9.0 at the outlet of the hydrogenation reactor, wherein the weight ratio of HPA to NPG in the hydrogenation feed is in the range from 1:100 to 50:100 and the proportion of HPA and NPG in the hydrogenation feed is at least 50% by weight, based on the hydrogenation feed, and the NPG-comprising stream comprises more than 30% by weight up to 80% by weight of NPG and 20 to 40% by weight of water., and, in the case that the pH regulator is supplied to the HPA-comprising stream, the HPA-comprising stream comprises less than 50% by weight of HPA.