Sapo-34 Molecular Sieve Synthesis And Study Of The Mto Process

Methanol to olefin(MTO) has reeeived wide attention in this world as a potential method instead of conventional oil route. SAPO-34 molecular sieve is a potential catalst because it has high selectivity of ethane and propene and conversion of methanol for MTO reaction. But using the traditional hydrothermal method synthesizes SAPO-34 molecular sieve easily caking and sticky. The topic developed a new preparation method of SAPO-34 molecular sieve - dry powder liquid transformation method. At the same time, systematically studied the impact of the synthesis of various factors.In this paper, crystallization mechanism of dry powder liquid transformation method has been to explore. Put forward a synthesis method of the assumption, that is the mechanism of melt crystallization. After a series of experimental studies and detailed analysis of the spectra, which confirmed the essential difference of the synthesis mechanism between the transformation of liquid dry powder transformation method and hydrothermal method.This article investigated the impact of dry powder liquid transformation SAPO-34 molecular sieve synthesis factors. The results showed that: (1) This method synthesized SAPO-34 molecular sieve crystallinity best, which used the higher the rate of plastic capacity, the less iron content of the pseudo-boehmite as the raw material (2) Powder in the lower water content, the better catalytic properties.Better crystallinity of SAPO-34 molecular sieve was synthesized by the crystallization process by adding water. In the rubber by adding template or acetate more easily generated miscellaneous crystal.In this paper, the best MTO reaction conditions were as follows: reaction temperature 440℃, methanol: water =1:1, WHSV for 3.6h-1, dp / D <1 /12, At this point, the methanol conversion rate of more than 98%, ethylene and propylene selectivity of 87% of the total. And catalyst regeneration after repeated, total ethylene and propylene selectivity is over 80% .The life of the catalyst is for 4h and good performance.This article has been appended catalyst to do the exploratory experiment, which use the new method. The results showed that: SiO₂ attached SAPO-34 molecular sieve at the methanol conversion rate of more than 99%, the total ethylene and propylene selectivity at 73% or more, MTO reaction of the general catalytic properties. Al₂O₃ annexed zeolite eggshell almost generates the majority of the DME.Finally, the paper also examined the template effects of recycling. Marked contrast, after series of characterization of materials, we can see: the use of dry powder liquid transformation method, re-use the template can synthesized purity, and high-performance catalyst for the SAPO-34 molecular sieve.