Epoxidation of propylene with H2 and O2 in the explosive regime in a packed-bed catalytic membrane reactor

The vapor-phase epoxidation of propylene with H2 and O2 over a highly dispersed Au/TS-1 catalyst was carried out in a packed-bed catalytic membrane reactor. The membrane reactor allowed the use of high concentrations of H2 and O2 (40% each) that were well within the explosive regime, and the production rate of propylene oxide was improved by 100–200% compared with that from a conventional packed-bed reactor. At 180 °C, the C3H6 conversion was 10% and the PO selectivity was 80%, corresponding to a space–time yield of 150gPOkgcat−1h−1, whereas at 212 °C, the yield increased to 200gPOkgcat−1h−1. The kinetic dependency, rPO=krPO=k (H2)0.53 (O2)0.26 (C3H6)0.18, obtained free from mass transport and heat transfer limitations at these high concentrations was in good agreement with that reported at low concentrations.