Preparation,Characterized And Catalytic Behavior Of High Crystallinity Mg/Al Hydrotalcites Catalyst For Synthesis Of Propylene Glycol Monomethyl Ether

Propylene glycol monomenthyl ether, an extensive using chemical, is frequently used as solvents, detergents and emulsifiers in industrial and consumer products. It is a one of research hot spots because its toxicity is lower than that of ethylene glycol ether. There are no problems such as the purification and separation of product as well as environment pollution in the application of the base heterogeneous catalysts but traditional homogeneous acid/ catalyst. In the thesis, Mg-Al hydrotalcite (LDH) was prepared, and some studies were done as follows:Mg-Al hydrotalcite (LDH) prepared with different methods was determined by XRD, IR, TG-DTA and BET. All the hydrotalcites in the methods have a hydrotalcite structure, and the one prepared with urea method has the best crystallinity, layer structure and the most symmetrical pellet. The catalytic activity of the hydrotalcite prepared using urea method on etherification of propylene oxide to methanol was higher than that using coprecipitation method.In addition, the studies for optimizing the etherification reaction conditions such as reaction temperature, reaction pressure, reaction time, the molar ratio of methanol to propylene oxide and catalyst amount were performed. The optimized parameters, the reaction temperature 140℃, catalyst amoun(tw/w) 0.9%, molar ratio of methanol to propylene oxide 4:1 and reaction time 4h gave the maximum ether conversion 93.8%, the yield 91.2% and the selectivity 97.2%, respectively. The solid catalyst could be reused for many times without decrease in activity and selectivity and possesses high stability.The propylene glycol monomethyl ether was determined by Gas chromatography (GC). The GC analysis was simple and sensitive and available for the production. The were good linearity of the calibration graphs and a wide range of the analysis concentrations.