Scale-up Synthesis Of Titanium Silicalite-1 And Utilization Of Its Mother Liquor

Catalytic oxidation system of titanium silicon-1 and H2O2 had good catalytic activity for many reactions, especially for propylene epoxidation to epoxy propane process. This process had been widely concerned because of its atom economy and environmental friendly. So whether TS-1 can be put into production is the key. In TPAOH hydrothermal system, the influence of TS-1 synthesized in different scale autoclaves on its catalytic performance was investigated. The concentration of TPA+ remaining in the mother liquor from synthesis was analyzed and the mother liquor was recycled in the synthesis of TS-1. The main results are as follows: 1. In different scale autoclaves synthesizing TS-1, although TS-1 synthesized in the scale-up autoclave had large amount of nonframework Ti and anatase TiO2, it also had small crystal size, small relative crystallization and right amount of weak acid centers on the surface which led to good catalytic performance. TS-1 was suitable for industrial production. 2. TPAOH solution and concentration of TPA+ in the mother liquor was titrated successfully using sodium dodecyl sulfate. The result was accurate and the error was small. The concentration of mother liquor from scale-up autoclave was 0.290 mol/L and the concentration of mother liquor from the lab was 0.188 mol/L. The amount of Si and Ti remaining in the mother liquor from scale-up autoclave was higher than the amount of Si and Ti remaining in the mother liquor from the lab. 3. In the silicon hydrolysis, when V(TPAOH)/V(mother liquor) was less than 6, the catalytic performance of synthesized TS-1 dropt; In the titanium hydrolysis, when V(TPAOH)/V(mother liquor) was less than 1.2, the synthesized TS-1 had bad catalytic performance. The requirement for amount of template and alkalinity in the silicon hydrolysis was loose, but strict in the titanium hydrolysis. Mother liquor recycle was suitable for silicon hydrolysis.