论文部分内容阅读
为了研究催化裂化汽油中硫化物的生成机理,在小型固定流化床(FFB)装置中考察了不同质量分数的庚烯与H2S在固体酸催化剂上的反应。结果表明,庚烯与H2S的反应主要生成噻吩类硫化物、部分硫醇、少量硫醚和痕量四氢噻吩等硫化物;庚烯质量分数越高,生成硫化物的量越多;噻吩类硫化物中生成量最大的甲基苯并噻吩的生成量也随着庚烯质量分数增加而线性增长。烯烃在催化剂B酸活性中心上吸附形成正碳离子,正碳离子与H2S结合生成硫醇,硫醇的生成遵循正碳离子机理。硫醇与烯烃反应生成硫醚。当反应温度为400~500℃,庚烯与H2S反应中,生成硫醇、硫醚的反应均为放热反应,硫醇的平衡收率较低,硫醚的平衡收率更低一些。
In order to study the formation mechanism of sulfide in FCC gasoline, the reaction of different mass fractions of heptene and H2S on solid acid catalyst was investigated in a small fixed-bed reactor (FFB). The results showed that the reaction of heptene with H2S mainly generated thiophenes, some thiols, a small amount of thioethers and traces of tetrahydrothiophene sulfide; the higher the mass fraction of heptene, the more the amount of sulfide; thiophene The yield of methylbenzothiophene, the largest amount of sulfide, also increases linearly with the increase of heptane mass fraction. Alkenes adsorb on the active site of catalyst B to form positive carbon ions, and the positive carbon ions combine with H2S to form thiols. The formation of mercaptans follows the mechanism of positive carbon ions. Thiols react with olefins to form thioethers. When the reaction temperature is 400-500 ℃, the reaction of heptene and H2S to generate thiol and thioether are exothermic reaction, the equilibrium yield of mercaptan is lower and the equilibrium yield of thioether is lower.