Process for preparing epoxides from olefins, hydrogen peroxide and a base in the presence of a titanium silicalite catalyst where the base is added at the start and/or during the process

摘要

Process for the preparation of an epoxide, comprising epoxidation of an olefinic compound with hydrogen peroxide in the presence of a titanium silicalite catalyst, where a solution containing hydrogen peroxide and the olefinic compound are introduced as starting substances periodically or continuously into an epoxidation reactor and a base is additionally employed in the process where the base is introduced into the epoxidation reactor directly or as a mixture with one or more of the starting substances, with pH control. The pH control is carried out in the reaction mixture or in the mixture(s) with a starting substance comprising the base and a pH in the range from 4 to 9.5 is established and kept substantially constant.