PROCESS FOR PREPARING ALKYLENE OXIDE

摘要

Process for the preparation of alkylene oxide, which process comprises passing a feed comprising an organic hydroperoxide and alkene through a bank of at least two serially connected reactors all containing a bed of heterogeneous epoxidation catalyst particles and operated in a cyclic mode, in which process:(a) the first reactor of the cyclically operated bank is put in a position further down this bank, when the activity of the epoxidation catalyst contained therein has decreased to an undesirably low level;(b) in this position the catalyst with decreased activity is contacted with the effluent from the reactor in the preceding position at a temperature which is at least 5° C. higher than the final temperature at which the catalyst was in use in the first position of the bank and for sufficient time to restore its activity to the desired level. The bank of cyclically operated epoxidation reactors may be followed by one or more additional fixed bed epoxidation reactors which are not operated cyclically.