原油直接催化裂解UPC工艺过程模拟与反应参数多目标优化

PROCESS SIMULATION AND MULTI-OBJECTIVE OPTIMIZATION OF UPC PROCESS FOR DIRECT CATALYTIC CRACKING OF CRUDE OIL

原油直接催化裂解技术可以实现从原油到三烯(乙烯、丙烯、丁烯)、三苯(苯、甲苯、二甲苯)的一步跨越,对我国炼化行业的转型升级具有重要意义。以全馏分石蜡基中原原油(159~780℃)为原料,采用混合馏分结构与分子组成集总建模策略,对原油直接催化裂解制烯烃(UPC)反应过程进行建模与工艺参数校准,并基于工业试验数据验证了其准确性。以多产烯烃、控制焦炭生成为目的,利用NSGA-Ⅲ多目标优化算法对模型进行了优化,得到优化后的操作参数。采用优化后的操作参数,即在第一段预热闪蒸温度为194.32℃、第二段预热闪蒸温度为228.16℃、第一段提升管反应器出口温度为615.73℃、第二段提升管反应器出口温度为622.59℃的条件下,UPC工艺得到的乙烯和丙烯收率之和为53.367%,焦炭收率为8.311%。此外,由于现行税费体系燃料型工艺路线税收贡献明显高于化工型工艺路线,UPC工艺参数优化后,烯烃收率大幅度提升,燃料油收率大幅度下降,原油生产总值降低44.30元t。

The direct catalytic cracking technology of crude oil can realize a one-step leap from crude oil to olefins and aromatics,which is of great significant implications for the transformation and upgrading of the refining industry in China.Using total fractions of paraffin-base crude oil(159-780℃)as raw materials,the modeling strategy of the structure of mixed fractions and molecular composition lumped-block was used to model and calibrate the process parameters of direct catalytic cracking of crude oil to olefin(UPC).The accuracy of this method was validated by using industrial test data.In order to produce more olefin and control coke formation,the model was optimized by using the NSGA-Ⅲmulti-objective optimization algorithm,and the optimized operational parameters were obtained.The optimized operating conditions were as follows:first-stage preheating flash temperature at 194.32℃,second-stage preheating flash temperature at 228.16℃,first-stage riser reactor outlet temperature at 615.73℃,and second-stage riser reactor outlet temperature at 622.59℃.The total yield of ethylene and propylene by UPC process was 53.367%,and that of coke was 8.311%.In addition,due to the fact that the tax contribution of fuel-based process was obviously higher than that of chemical process,the olefin yield was greatly increased and the fuel oil yield was greatly decreased after the optimization of UPC process parameters,and the gross value of crude oil production decreased by RMB 44.30 Yuan t.