Patent ID: 8466299

Claim:
A process for preparing a delta-valerolactone from 1,5 pentanediol, comprising: a) evaporating the 1,5-pentanediol in an inert gas stream wherein the inert gas is selected from the group consisting of hydrogen, nitrogen, argon, and methane; b) passing the inert gas stream comprising 1,5-pentanediol through a catalyst bed comprising at least two different copper based catalysts in a layered structure wherein the catalyst bed has an inlet temperature in the range of from 260 to 350° C. and an outlet temperature in a range of from 180 to 240° C., to obtain a gas mixture; and (c) condensing a reaction product out of the gas mixture obtained in b) wherein the catalysts have a layer structure such that the inert gas stream comprising 1,5-pentanediol flows first through the catalyst which exhibits the highest conversion and selectivity for preparing the delta-valerolactone proceeding from 1,5-pentanediol at a given catalyst bed inlet temperature, and then through the catalyst which exhibits the highest conversion and selectivity for preparing the delta-valerolactone proceeding from 1,5-pentanediol at a lower temperature.