Patent ID: 8247580

Claim:
A process for preparing ε-caprolactone in a purity of more than 99%, the process comprising: (c) cyclizing a 6-hydroxycaproic ester in a liquid phase at from 150 to 400° C. and from 1 to 1020 hPa abs.; (d) removing and condensing any compounds which are volatile under cyclization conditions, to separately obtain ε-caprolactone and a remaining bottom product; (e) thermally treating the remaining bottom product from the cyclizing (c) in at least one further reactor in the presence of from 0.1 to 90% by weight of at least one further alcohol comprising a monool, diol, or polyol, to obtain a treated bottom product; (f) removing and condensing any volatile compounds from the treated bottom product, to obtain a condensate; and (g) distilling the condensate to obtain the ε-caprolactone from the condensate, wherein the further alcohol has a boiling point above a boiling point of caprolactone under reaction conditions.