Synthesis Of Propylene By Co - Cleavage Of Methanol And Butene On HZSM - 5 / MCM - 41 Composite Molecular Sieve Catalyst

propylene is an important organic chemical raw material of petrochemical industries and propylene can produce a variety of important other chemical raw materials. In the present situation of our country in the production of propylene, the demand of propylene is much higher than the annual and propylene imports are continue growing so that the propylene production status is still in short supply. In our country propylene is produced from steam cracking and fluid catalytic cracking (FCC). But, traditional methods of production of propylene in our country can not meet the needs of market. So by cogeneration steam cracking of crude oil cracking and propylene have been insufficient to meet the status quo, the development and production of propylene new technology is imminent.The reaction of coupling of C4hydrocarbon and methanol to propylene was benefit for the balance of heat and energy. The reaction of coupling of C4hydrocarbon and methanol Improve the cracking of methanol and butene ability to increase the yield of propylene, and avoid the center of the catalyst activity caused by the high temperature deactivation of the catalyst. This will not only increase the stability of the reaction, but also the catalyst activity and selectivity can be improved.In this work, Micro-mesoporous composites molecular sieves HZSM-5/MCM-41were prepared by different methods such as hydrothermal technique and mechanical mixture, and research their catalyst activity in the reaction of coupling of C4hydrocarbon and methanol to propylene. The effect of catalyst preparation method and composition were investigated and select the best catalytic effect composite zeolite to optimize the reaction conditions. The physicochemical properties of these catalysts were test by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FT-IR), N2isotherm adsorption-desorption (BET), Scanning electron microscopy (SEM) and Programmed desorption of ammonia (NH3-TPD) and transmission electron microscopy (TEM).The correlation between their acidity properties and catalyst performance was discussed researching the influences of zeolite acidity and complex mesoporous molecular sieve amount of butene-coupled catalytic properties of methanol to propylene.The main research result are shown as follows:(1) Research the effects of composition and synthesis of HZSM-5/MCM-41composite zeolite catalyst for methanol to propylene butene-coupled catalytic properties, and select the best catalyst effect were investigated optimal reaction conditions. Under the optimal reaction conditions(550℃, atmosphericpressure,spacetime=2.1gcatalysthymolCH2, methanol/1-butene molar ratio=3/1) the catalyst of ZS-HS-2has a relatively high yield of propylene in the reaction, about37.9%. studying catalyst stability in the reaction, we found that the Hydrothermal stability of the ZS-HS-2catalyst was superior than the catalysts prepared by mechanical mixing.(2) Using XRD, BET, TEM and TPD techniques a series of characterization for composite zeolite catalyst structure, acidity and specific surface area and total pore volume. The results can be seen through the characterization that there were some chemical changes in the micro-mesoporous composite molecular sieve HZSM-5/MCM-41prepared by Hydrothermal technique. The MCM-41molecular sieves in the HZSM-5/MCM-41micro-mesoporous composite molecular sieve was absorbed by HZSM-5in the HZSM-5/MCM-41micro-mesoporous composite molecular sieve, not only make the specific surface area and total pore volume of composite zeolite catalyst increases, but also through modulation composite zeolite MCM-41and ZSM-5quality than composite zeolite catalyst can change the acidity.(3) Using the different concentrations NH4F Solutions modified ZSM-5before the hydrothermal technique to HZSM-5/MCM-41micro-mesoporous composite molecular sieve. Doing some research of HZSM-5/MCM-41micro-mesoporous composite molecular sieve which have different F" ion concentration,we found that suitable concentration of F-ion in HZSM-5/MCM-41micro-mesoporous composite molecular sieve had some promotion in The reaction of coupling of C4hydrocarbon and methanol to propylene.