PROCESS FOR OPERATING THE EPOXIDATION OF ETHYLENE

摘要

There is provided a process for the vapor phase oxidation of ethylene to ethylene oxide in the presence of a supported highly selective silver-based catalyst, the process comprising operating fresh catalyst for an initial operation phase, then operating at a further operation phase when the catalyst has reached an advanced aged defined by a cumulative ethylene oxide production exceeding 1.5 kT EO per m3 of catalyst. In the further operation phase the composition of the reaction mixture is changed to contain from 1.1 to 4 times the concentration of ethylene used in the initial operation phase and the corresponding optimised and safe concentration of oxygen.