Patent ID: 9096563
Filing Date: 2015-08-04
Classification: C07D

Abstract:
1. A method for the start-up of a process for the epoxidation of ethylene comprising: initiating an epoxidation reaction by reacting a feed gas composition containing ethylene, oxygen and a chloride moderator in the presence of a silver-based epoxidation catalyst at a first temperature from about 180° C. to about 230° C., wherein said chloride moderator is present in the feed gas composition at a concentration of greater than 1 ppm, and wherein said epoxidation reaction has a selectivity of less than 86%; increasing the first temperature to a second temperature of about 235° C. to about 270° C. at a ramp of 0.5° C./h to about 10° C./h in the presence of the feed gas composition used during said initiating; maintaining the second temperature over a time period of from about 10 hours to about 400 hours in the presence of the feed gas composition used during said initiating; reducing the concentration of the chloride moderator in the feed gas composition below that used during said initiating; and reducing the second temperature to a third temperature in the presence of said feed gas composition including said reduced concentration of chloride moderator.