Methyl lactate(MLA)is an important biomass-based platform chemical.The alcoholysis of biomass sugar to produce MLA using Snβ zeolite is promising for industrial application.Currently,research about preparation processes of Snβ zeolites catalysts on their activity and reusability is incomplete.The parameters of dealumination,impregnation and calcination processes during Snβ zeolites preparation on their structure and catalytic performance in the conversion of fructose to MLA were investigated in this study.The results show that strong acids are needed in the dealumination step of commercial Hβ zeolite during the preparation of Snβ zeolites,and nitric acid is the best.Optimal conditions are existed considering the molar ratio(n(Si):n(Al))of original Hβ zeolite,HNO3 concentration for dealumination,SnCl2 concentration for impregnation and calcination temperature.Specifically,the catalyst obtained using Hβ zeolite with n(Si):n(Al)of 60 as raw material,dealuminating with 47%HNO3,impregnating in 0.1 mol·L-1 SnCl2 ethanol solution,and calcining at 550℃for 6 h has the best reactivity,which gives MLA yield of 53.6%at 180℃for 6 h.In addition,the catalyst has good reusability.Characterization results show that Sn is incorporated in the framework of β zeolite in the catalyst prepared by the above process.This study provides a guidance for the industrialization of MLA preparation from biomass via heterogeneous catalytic alcoholysis.
关键词
果糖/乳酸甲酯/Snβ分子筛/催化剂制备工艺
Key words
fructose/methyl lactate/Snβ zeolite/catalyst preparation process
维普
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