类型硫在催化裂化过程中的转化机理分析及脱硫方法探讨

主要对原料油中噻吩、苯并噻吩、硫醚等类型硫在催化裂化过程中的转化机理和路径去向进行了综述和分析,并与催化汽油中类型硫的标定结果进行了对比;讨论了催化操作条件、催化剂类型及原料油组成对类型硫的裂化脱硫过程的影响,对于两种主要脱硫技术吸附脱硫和加氢精制进行了探讨。噻吩在催化剂B酸中心易形成β碳正离子并进一步转化为不同的中间产物,再经过氢转移反应和裂化反应开环裂化脱硫生成H 2S进入气相,或生成烷基噻吩等硫化物主要进入汽油馏分段,苯并噻吩和二苯并噻吩比噻吩更难开环裂化,其脱硫产物主要进入柴油馏分段。较低的反应温度、较高的剂油比、较长的反应时间、晶胞参数高、酸密度大的催化剂及较多的供氢剂有利于脱除类型硫。

Analysis of the transformation mechanism of type sulfur in the process of catalytic cracking and study on the desulfurization method

The conversion mechanism and path of the type sulfur in raw oil, such as thiophene, benzothiophene, and sulfide ether in the process of catalytic cracking, and the results of calibration of the type sulfur in catalytic gasoline were compared with the influence of the catalytic operation conditions, catalyst type and raw oil composition on the cracking and desulfurization process of the type sulfur. The adsorption desulfurization and hydrofining of two main desulfurization technologies were discussed. The beta carbon positive ions were easily formed in the center of the catalyst B acid and further converted into different intermediate products, then through the hydrogen transfer reaction and the cracking reaction cracking desulfurization of hydrogen into the gas phase or the generation of alkyl pyridine and other sulphides mainly into the gasoline distillation segment, benzothiophene and dibenzothiophene are more difficult than thiophene to crack the ring. Its desulfurization products mainly enter the diesel distillation segment. Lower reaction temperature, higher agent oil ratio, longer reaction time, high acid density catalysts with high cell parameters, and more hydrogen supply are beneficial to the removal of type sulfur.