流化催化裂化汽油含硫化合物生成规律的考察

在小型固定流化床装置上采用流化催化裂化(FCC)催化剂、以FCC汽油轻馏分和H2S标准气为原料,考察了催化剂类型、原料组成和反应条件(反应温度、催化剂与原料油的质量比(剂油比)和重时空速)对硫化物生成的影响。实验结果表明,FCC汽油中的烯烃与H2S反应主要生成噻吩类硫化物和部分硫醇;在REUSY分子筛催化剂(催化剂A)上的硫化物收率比在ZRP型择形分子筛催化剂(催化剂B)上的高;且硫化物收率随H2S和烯烃含量的增加呈线性增长。受反应温度对烯烃转化程度的影响,较高的反应温度有利于抑制烯烃与H2S反应。因为反应机理及催化剂性质对噻吩类硫化物和硫醇的生成影响不同,两者收率随剂油比和重时空速的变化趋势不同,但变化幅度均不大,因而总硫化物收率随重时空速和剂油比的变化幅度也不大。

Formation of Sulfur Compounds in Fluid Catalytic Cracking Gasoline

Formation of sulfur compounds in light fraction of the fluid catalytic cracking (FCC) gasoline was investigated in a small fixed fluidized bed unit with two kinds of FCC catalysts. Effects of catalyst type,feedstock composition and reaction conditions including temperature,mass ratio of catalyst to oil and WHSV on formation of sulfur compounds were studied. Olefins in FCC gasoline reacted with H2S and were transformed mainly into thiophenes(mainly thiophene and alkyl thiophenes)and partly into thiols. Yields to sulfur compounds from REUSY zeolite catalyst (catalyst A) were higher than that from shape selective zeolite ZRP zeolite catalyst (catalyst B). Yields to sulfur compounds varied linearly with mass fractions of H2S and olefins in reaction system. Due to influence of temperature on conversion of olefin in FCC process,higher temperature is favorable to inhibit formation of sulfur compounds. Due to different formation mechanisms of thiophenes and thiols,and different properties of catalysts,the influences of mass ratio of catalyst to oil and WHSV on yields of two sulfur compounds are different,but their variation ranges are not large.