Preparation And Application Of ZSM-5Zeolite Molecular Sieve

ZSM-5zeolite was widely used in applications such as catalysis, adsorption, coal chemical industry due to a unique structure and preferably hydrothermal stability. Both the morphology and size of zeolite have significant impact on its catalytic and separation performance. In this paper the influence on MFI zeolite’s morphology and size in microemulsion system and hydrothermal system are investigated. In addition, the recycling of mother liquor in the synthesis of ZSM-5zeolite in hydrothermal system was preliminary studied. The main findings are as follows:(1) We have studied the phase consists of n-heptane, CTAB (cetyl trimethyl ammonium bromide), n-butanol and water by the using of visual autoclave in different temperatures; The result shows that the ratio of CTAB/TPAOH, the composition of microemulsion system, the silicon source and content of the oil phase all have significantly influence on the phase of the system.(2) Synthesis of silicalite-1zeolite and ZSM-5zeolite in different phases was studied, The result shows that the content of surfactant is the key factor to the degree of crystallization and morphology of the final product in the microemulsion system.(3)The research on the ZSM-5zeolite in the hydrothermal system shows that the increase of alkalinity can result in a decrease of crystal size and an increase of crystallinity in the hydrothermal reaction system. However the degree of crystallinity of the as-synthesized zeolite decreases with increase of the content of alkality. The template can contribute to generating a uniform crystal size and shape zeolite. There is little change in crystallinity when the content of H2O is increased or reduced in this paper.(4)The mother liquor recycling in studied and the result shows that the morphology of the crystals obtained by mother liquor instead of deionized water is more regular and its edges are more distinct.