Abstract: In order to overcome the disadvantages of the existing technologies for propylene oxide (PO) production, SINOPEC has developed a new hydrogen peroxide propylene oxide (HPPO) process by using silicon-rich surface hollow titanium silicalite molecular sieves as catalytic component, and the first 100 kt/a HPPO industrial plant in China has been built. The surface silicon-rich multi-hollow titanium-silicon molecular sieve was invented, and the high-efficiency hydroxyl coupling binder was developed, which could simultaneously increases the active component content and the catalyst strength under low-temperature reaction conditions. A composite auxiliary agent was developed, which regulated the formation of a "five-member ring" transition state between hydrogen peroxide and framework titanium, thus greatly improving PO selectivity. The separation and purification technology of PO by low temperature separation, extractive distillation and chemical de-impurity coupling was explored to enhance the product quality. PO wastewater was used as terminator in catalytic cracking unit to make organic matter cracking into low carbon hydrocarbons such as ethylene and propylene. Compared with foreign reference technologies, the impurity total aldehyde is 80% lower, the moisture content is 50% lower, the hydrogen peroxide conversion rate is 3.3% higher, the PO selectivity is 3.6% higher, the purity of PO product is 99.99% , and the rate of high grade product is 100%.

Key words: hollow titanium silicate, HPPO, propylene oxide, epoxidation