晶粒尺寸对ZSM-5丙烯选择性的影响

ZSM-5分子筛由于其独特的骨架结构和酸性等特性,广泛用于石油化工领域。在催化裂化过程中,ZSM-5分子筛及其改性产品经常被加入以提高产品性能和选择性,特别是提升汽油辛烷值,增产丙烯等高附加值化工原料。通过严格控制化学合成与制备条件,制备具有相同晶体形貌、硅铝物质的量比约100和晶粒尺寸2.5μm至100 nm系列分子筛。研究分子筛的酸性、晶粒尺寸和比表面积对分子筛热稳定性、水热稳定性、活性和孔道等的影响。制成FCC助剂后,利用ACE和炼油厂原料考察FCC助剂在催化裂化反应中的性能,结果表明,硅铝物质的量比为80~100和晶粒尺寸为2.5μm的ZSM-5分子筛,可以获得最佳的丙烯选择性。

Influence of particle size of ZSM-5 molecular sieves on the selectivity to propylene

ZSM-5 molecular sieve is widely used in the petrochemical field due to its special framework structure and unique acidity.ZSM-5 molecular sieve and it’s modified products are frequently applied in FCC process in order to improve the properties of and the selectivity to the products,enhance the octane number of gasoline and increase propene yield.A series of ZSM-5 molecular sieves with the same crystal morphology,silica/alumina molar ratio of about 100 and particle size of 2.5 μm-100 nm were prepared by adjusting the synthetic condition.The influence of acidity,particle size and specific surface area of the molecular sieves on their thermal stability,hydrothermal stability,activity and porous properties was investigated.FCC additives were prepared,and then their properties for raw material catalytic cracking of oil refinery were evaluated by ACE.The results showed that ZSM-5 molecular sieve with silica/alumina molar ratio of 80-100 and particle size of 2.5 μm possessed the optimal selectivity to propene during FCC reaction.