Synthesis of Modified β -Zeolite Under Microwave Irradiation and Its Use on Etherification

摘要

β -zeolite was synthesized by using tetraethyl ammonium hydroxide as the template reagent and microwave radiation as the heat source. The effect of the sol composition and the radiation temperature on zeolite crystallinity was investigated. The zeolite was tested and compared with the commercial product, which was produced by conventional hydrothermal synthesis method. The physico-chemical properties of the synthesized samples, the specific surface area of the samples synthesized under microwave irradiation and pore volume measured by X-ray diffraction apparatus, were better than the conventional samples. The etherification experiment on FCC light naphtha in the presence of transition metals modified H β -zeolite, which was synthesized firstly under microwave irradiation, was studied in a fixed-bed reactor. The effect of catalyst preparation conditions on its activity, stability and the effect of reaction temperature, methanol/tertiary-carbon olefin molar ratio and liquid hourly space velocity on the etherification reaction were discussed. The experimental results showed that the different metals modified H β -zeolite had different etherification performances. And the conversion of tertiary carbon-olefins of the molybdenum modified H β zeolite, which was loaded at a concentration of 3 percents, was higher than that on 6.0 percent of H β zeolite. The modified H β zeolite catalysts possessed favorable prospects for its higher stability.