Study On Catalytic Dehydration Of Ethyl Lactate Over ZSM-5 Modified With Transition Metal

Acrylic acid and its ester derivatives are principal raw materials in the manufacture of polymeric pmducts. The polymers made of acrylic acid and its derivatives are characterized by color lasting, stability to light, moderate heat as well as weathering. And they are widely applied in surface coatings, textiles, adhesives, paper treatment, polishes, leather, fibers, and super-absorbent polymer, etc.Based on detailed investigation of related literatures, the dehydration reaction of ethyl 1actate was determined, which was carried out over Fe3+, Mn2+ and La3+modified HZSM-5 in a non-pressurized reator. In this paper, I have researched the condition of modification and got the La-ZSM-5 catalyst with benign activity. The activity of modified catalyst was tested with ethyl lactate, it showed good catalytic activity, and optimized the condition of modification and dehydration. At last, did some tests about dynamics for ethyl lactate dehydration. This technics has some advantages, such as save energy, equipment can be controlled easily and so on. Petroleum resource is unrenewable and drying up gradually, which brings great challenge for the acrylate industry, so it should explore other raw materials to compensate the petroleum resource. So it is a good chance for the technology that lactate dehydration to acrylate to develop.The results of catalyst modification showed that when the Si/Al ratio of HZSM-5 was 38, modified temperature was 80℃, the concentrations of La(NO3)3 were 60%, the modified time was 4h, and the calcination temperature was 550℃, the catalytic activity of modified HZSM-5 was better. The conversion rate of material and selectivity of product were over 70% and 20% respectively. The results of dehydration condition that when the concentration of ethyl lactate was 60%~100%, reaction temperature was 250℃, the selectivity of ethyl arcylate were over 15%. Under the optimum experimental conditions, the HZSM-5 and modified ZSM-5 were characterized by GC-MASS. The result indicated that transformation and pyrolysis products were ethyl arcylate, ethanol, butanol, acetate and 2,3- butanediol.The HZSM-5 and modified ZSM-5 were characterized by XRD, FT-IR and BET techniques. The result indicated that Fe3+, Mn2+ and La3+were located in the zeolite frame, and the crystal structure of the modified zeolites were not changed.