Propylene epoxidation with aqueous hydrogen peroxide

An issue which deserves further mention is the environmentally fiiendly nature of TS-l/H Oj system. It involves the use of a safe silica based catalyst, titanium silicalite, and a reagent, hydrogen peroxide, which yields water as the coproduct. This holds for the in situ route illustrated in Scheme I and also for the epoxidation of propylene with preformed hydrogen peroxide, either used as an aqueous solution (72) or extracted by means of die epoxidation solvent (Scheme 11). Hazardous chemicals, such as chlorine, performic or other organic peracids, are not required in the process. The disposal of chlorinated salts or the recycle of brine (chloroydrin process) and any possible burden resulting from the coproduction of odier chemicals (styrene and r-butanol in the hydroperoxide route) are eliminated. The liquid phase oxidation of isobutane and ethylbenzene with air under pressure and at high temperature, to produce... 

The TS-1 catalyst has also been found effective in the epoxidation of olefinic compounds. It is of particular interest in the preparation of propylene oxide by oxidation of propylene with hydrogen peroxide (Hoelderich, 1988). Ethylene has also been epoxidized to ethylene oxide with 30% H2O2 in aqueous /-butanol to obtain 96% selectivity at 97% H2O2 conversion (Sheldon, 1991). 

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