METHOD FOR SYNTHESIZING SAPO-34 MOLECULAR SIEVE WITH LOW SILICON CONTENT

摘要

Provided is a method for synthesizing SAPO-34 molecular sieve with a low silicon content, wherein the molar ratio of silicon and aluminium in the SAPO-34 molecular sieve is: Si/Al = 0.01 - 0.15. The method comprises the following steps: a) heating an initial gel mixture formed from silicon source, aluminium source, phosphor source, water and organic amine to 150 - 210?, and crystallizing at constant temperature under autogenous pressure for 0.1 - 24 hours to obtain mixture a), with the molar ratios in the initial gel mixture being: SiO2/Al2O3 = 0.21 - 1, P2O5/Al2O3 = 0.5 - 1.5, H2O/Al2O3 = 20 - 150, R/Al2O3 = 0.5 - 10, wherein R is organic amine; b) adding the mixture gel of phosphor source, aluminium source and organic amine into the mixture a) to obtain mixture b), with the molar ratios in the mixture gel being: P2O5/Al2O3 = 0.5 - 1.5, H2O/Al2O3 = 20 - 150, R/Al2O3 = 0.5 - 10, wherein R is organic amine; c) crystallizing the mixture b) at 150 - 210 ? for 1 - 48 hours. The SAPO-34 molecular sieve is calcinated at 400 - 700 ? in air to obtain a catalyst for acid catalyzed reactions or for conversion reactions of oxygen-containing compounds to olefins.