复合催化剂上合成气一步法制备液化石油气的研究

摘要

合成气一步法制备液化石油气(LPG)可在甲醇合成催化剂和分子筛组成的复合催化剂上实现.本实验选用与Y分子筛孔径相近的SAPO-5分子筛(0.73 nm×0.73 nm)作为研究对象,在335℃、3.0 MPa、空速1 500 h-1、Cu-Zn-Al/Pd-SAPO-5质量比为1/2的条件下获得了73.9％的CO转化率和73.0％的LPG选择性,该结果进一步证实了较大孔径的分子筛有利于LPG的合成.此外,研究结果还表明,合成气一步法制备LPG过程中甲醇/二甲醚向烃类的转化遵循烃池机理.%Direct synthesis of liquefied petroleum gas (LPG) from syngas could be realized over a hybrid catalyst consisting of methanol synthesis catalyst and zeolite.In this work,SAPO-5 was chosen consciously for LPG synthesis,because its pore size (0.73 nm×0.73 nm) is similar to that of Y zeolite.As expected,the corresponding hybrid catalyst of SAPO-5 exhibits high selectivity (73.0％) to LPG,which confirms the previous deduction that large pore size of zeolite was beneficial to LPG synthesis.In addition,as one step process of syngas to LPG,the formation of hydrocarbons from methanol or dimethyl ether follows the hydrocarbon pool mechanism.