直馏柴油催化裂化生产轻质芳烃的研究

STUDY ON STRAIGHT-RUN DIESEL FRACTION TO LIGHT AROMATICS

采用小型固定流化床催化裂化装置,考察了分子筛类型和反应条件对直馏柴油催化裂化反应的影响以及不同烃类组成的直馏柴油催化裂化产物分布特点。结果表明:选用富含环烷烃和单环芳烃的直馏柴油有利于提高轻质芳烃收率;在Y型分子筛催化剂作用下的直馏柴油催化裂化转化率最高,轻质芳烃收率可达13.22%;反应温度对轻质芳烃收率影响显著,反应温度由510℃提高到610℃时,转化率增加12.95百分点,轻质芳烃收率增加7.16百分点,提高原料的转化深度有利于增加轻质芳烃收率,但是汽油收率降低;剂油比对轻质芳烃收率影响较小,剂油比过高时,汽油收率下降。与直馏柴油相比,其催化裂化产物烃类组成中环烷烃质量分数减少26.4百分点,环烷烃参与反应的比例高达80.49%,环烷烃环数越多,参与反应的比例越高。

Catalytic cracking experiments of straight-run diesel were conducted in a fixed fluidized bed reactor to study the effect of operation parameters and catalysts containing three different zeolites on product slates. The results showed that the straight-run middle distillate rich in naphthenic hydrocarbons and monocyclic aromatics has a higher yield of light aromatics. The higher conversion rate and gasoline and light aromatics yields are obtained using Y type zeolite catalyst and the light aromatics yield is up to 13. 32%. As the reaction temperature increases from 510 °C to 610 °C , the conversion is increased by 12. 95 percentage points and the yield of light aromatics is increased by 7. 16 percentage points. The ratio of catalyst/oil has little effect on the yield of light aromatics ？ but the yield of gasoline decreases when the ratio is too high. The cracking products have 26. 4 percentage points naphthene less than that of the SR diesel feed, indicating more than 80. 94% naphthene hydrocarbons to participate in the reaction. The more ring number in the naphthene,the higher the proportion of the naphthene involved in the reaction.