Selective synthesis of epichlorohydrin via liquid-phase allyl chloride epoxidation over a modified Ti-MWW zeolite in a continuous slurry bed reactor

Abstract

The epoxidation of allyl chloride (ALC) to epichlorohydrin (ECH) with H₂O₂ using a piperidine (PI)-modified Ti-MWW catalyst (Ti-MWW-PI) in a continuous slurry reactor was investigated to develop an efficient reaction system for the corresponding industrial process. The reaction parameters, including solvent, reaction temperature, t-butanol/ALC mass ratio, ALC/H₂O₂ molar ratio, weight hourly space velocity of H₂O₂, and the addition amount of ammonia, were studied in detail to pursue high H₂O₂ conversion and ECH selectivity. A long catalytic lifetime of 244 h was achieved at high H₂O₂ conversion (>97.0%) and ECH selectivity (>99.8%) under optimized reaction conditions. The crystallinity was well maintained for the deactivated Ti-MWW-PI catalyst, which was regenerated by a combination of calcination and piperidine treatment.