Abstract:

The research of a new heavy oil catalytic cracking process in reducing olefin content in gasoline and increasing propylene production was introduced. The reaction temperature and catalyst to oil ratio of heavy oil catalytic cracking to light olefins were investigated in a fixed fluidized bed unit. When the reaction temperature is less than 560 ℃, catalytic cracking reaction is the main reaction; When the reaction temperature is 590 ℃, catalytic cracking and thermal cracking react together; With the increase of catalyst oil ratio, the reaction rates of thermal cracking and catalytic cracking increased. The results of the pilot scale test show that when the temperature of the supplementary regenerated catalyst is 400 ℃, compared with the blank test, the yield of heavy oil decreases by 2.37 percentage points, the yield of propylene in LPG increases by 1.35 percentage points, and the olefin content in gasoline decreases by 8.64 percentage points; When the temperature is 600 ℃, the yield of heavy oil decreases by 3.22 percentage points, the yield of propylene in LPG increases by 3.05 percentage points, and the olefin content in gasoline decreases by 10.08 percentage points. From the view of mechanism analysis, it should be appropriate with high temperature, high catalyst to oil ratio and short reaction time to ensure the olefin formation and promote the reaction of olefin, which is conducive to the generation of small molecule light olefins.

Key words: FCC, olefin in gasoline, reaction temperature, catalyst to oil ratio, light olefin, propylene, reaction mechanism

摘要：

介绍了新型重油催化裂化工艺在降低汽油烯烃含量和增产丙烯方面的研究，在固定流化床装置上对重油催化裂解制低碳烯烃的反应温度和剂油比进行了考察。当反应温度小于560℃时，以催化裂化反应为主；当反应温度为590℃时，催化裂化和热裂化反应共同作用；随着剂油比的增加，热裂化反应与催化裂化反应均增强。中型试验结果表明：与空白试验相比，补充再生催化剂温度为400℃时，重油收率降低了2.37百分点，液化石油气中丙烯收率提高了1.35百分点，汽油烯烃质量分数降低8.64百分点；补充催化剂温度为600℃,重油收率降低3.22百分点，液化石油气中丙烯收率提高3.05百分点，汽油烯烃质量分数降低10.08百分点。从机理分析来看，该反应以高温、大剂油比和短反应时间的条件为宜，这样既能保证烯烃的生成，又有利于烯烃反应生成小分子低碳烯烃。

关键词: 催化裂化工艺, 汽油烯烃, 反应温度, 剂油比, 低碳烯烃, 丙烯, 反应机理