Kontrollierte Oxidation von Propylen

摘要

Continuous prodn. of propylene oxide (PO) and t-butyl alcohol (TBA) is effected in a reactor system comprising an isothermal segment followed by an adiabatic segment, where the isothermal segment comprises at least four internally cooled reactors (ICRs) connected in series. The process comprises: (a) charging the first ICR with a feed comprising 25-75 wt.% propylene and 25-75 wt.% of a recycle stream; (b) charging each of the ICRs with a t-butyl hydroperoxide (TBHP) feed stream comprising a TBA soln. of TBHP and a Mo catalyst at a rate such that the isothermal segment is supplied with 1-3 moles propylene per mole TBHP; (c) adjusting the TBHP feed rate and heat removal rate in each ICR so that each ICR has the same inlet temp. and 50-80% of the TBHP is reacted; (d) removing a recycle stream from the isothermal segment effluent and returning it to step (a); (e) passing the rest of the effluent through the adiabatic segment to convert an additional 15-30% of the TBHP; and (f) recovering PO from the prod. Also claimed are two processes as above incorporating prefd. features.