催化干气制乙苯和高辛烷值汽油组分技术开发与应用

摘要

Aiming to fully utilize the dilute ethylene of FCC off gas of the refinery,the process technology for ethylbenzene production from dilute ethylene was developed. The technique used the pre-treatment process to remove propylene and butylenes from raw dry gas,and SEB series catalysts for the vapor phase alkylation of benzene with dilute ethylene. Under the condition of reaction temperature(320 - 380)℃,reaction pressure(0. 7 - 1. 0)MPa,benzene / ethylene molar ratio 5. 0 - 7. 0,ethylene conversion was more than 99% . For production of 1 ton ethylbenzene,the consumption of benzene and ethylene in FCC off-gas,and the energy consumption were 0. 75 t,0. 275 t and 150 kilograms of standard oil,respectively. The purity of ethylbenzene was over 99. 8% and the content of main impurity xylene in the product was < 0. 08% . This process technology had been applied successfully in 9 plants. Because the octane rating in the blended gasoline was insufficient,the process for dilute ethylene to produce ethylbenzene was optimized,in which the pre-treatment unit of removing propylene was omitted and other distillation units following benzene column were cut,and therefore benzene / ethylene molar ratio could be reduced to 4. 0 - 5. 0. Energy consumption of per ton product was reduced to about 80 kilograms of standard oil,and the octane rating of the obtained blended gasoline was up to 108. 1,which met the requirement of octane rating of the blended gasoline. The resource of dilute ethylene was effectively utilized. The two techniques could help the comprise to flexibly produce ethylbenzene or high-octane rating gasoline component according to the market and plant’s operation situation.%为充分利用炼油厂干气中的稀乙烯资源，设计开发了稀乙烯制乙苯成套技术（SGEB）。该技术采用预处理工艺脱除原料干气中的丙烯和丁烯，苯和乙烯气相烷基化反应部分使用高效 SEB系列稀乙烯制乙苯催化剂，在反应温度（320~380）℃、反应压力（0.7~1.0）MPa 和苯烯物质的量比为5.0~7.0条件下，乙烯转化率达99%以上。利用该技术进行生产的能耗和物耗较低，每吨乙苯的苯单耗为0.75 t、乙烯单耗0.275 t、综合能耗150 kg 标准油，产品乙苯纯度超过99.8%，主要杂质二甲苯含量低于0.08%，该技术已在国内9套装置上成功应用。同时，根据部分炼油厂汽油辛烷值不够的实际情况，对干气制乙苯技术进行工艺优化设计，停用脱丙烯预处理单元，分离单元仅到苯分离塔为止，烷基化反应苯烯物质的量比可降低至4.0~5.0，每吨产品的能耗降低至约80 kg标准油，得到的调和汽油组分辛烷值高达108.1，有效利用干气资源满足了企业汽油调和辛烷值的要求。采用开发的两种技术，企业可根据市场和自身情况灵活选择生产乙苯或高辛烷值汽油组分。