Green and efficient epoxidation of propylene with hydrogen peroxide (HPPO process) catalyzed by hollow TS-1 zeolite: A 1.0 kt/a pilot-scale study

The propylene epoxidation catalyzed by hollow TS-1 zeolite with 30 wt% H 2 O 2 solution as oxidant at 1.0 kt/a pilot plant has been examined. Rising reaction temperature is in favor of increasing TOF of H 2 O 2 but reduces the selectivity of PO, due to the promotion of major and side reactions at the same time. Enhancing the CH 3 OH amount and the WHSV of H 2 O 2 is preferential to improving the TOF of H 2 O 2 and the selectivity of PO, but increase capital and energy consumption as well. Taking all into consideration, the optimized epoxidation has been confirmed: T is 40–50 °C; molar ratio of CH 3 OH/H 2 O 2 is 5–15, and the WHSV of H 2 O 2 is more than 1.2 h −1 . When the epoxidation of propylene carried out over 6000 h, the TOF of H 2 O 2 is 30.9–32.2 mmol g −1  h −1 and the PO selectivity is 96–99%, respectively. The final PO product from this plant is at 99.97% purity, which has been used as an intermediate to synthesize kinds of chemicals.