催化裂化分馏与换热过程模拟及综合优化

以国内某设计规模为240×104 t/a催化裂化(FCC)装置为背景，采用流程模拟系统Aspen Plus建立催化裂化反应油气分馏过程模拟模型；采用夹点分析和?分析方法对FCC装置的分馏及换热过程用能进行分析评价，找出过程用能瓶颈，对分馏与换热过程?损失偏大的问题提出相应的节能改进措施。结果表明：通过优化调整主分馏塔回流取热比例，合理提高高温位回流取热量，过程?总量32.71 MW增加到34.03 MW，?效率提高了4.0%；经换热网络优化后，装置多产压力为3.5 MPa的蒸汽流量约13.4 t/h，吸收稳定系统节约压力为1.0 MPa的蒸汽流量约11 t/h，产品油浆高温热量回收0.81 MW，过程低温余热回收增加2.91 MW，换热过程?总量从24.83 MW增加到27.70 MW，过程?效率提高了11.5%。

Simulation and Energy Optimization of Heat Exchange and Fractionation Processesfor Fluid Catalytic Cracking Unit

The fluid catalytic cracking unit (240×104 t/a) in a domestic refinery has considerable exergy loss for both fractionation process and heat exchanger network. Both pinch analysis and exergy analysis are performed quantitatively and qualitatively based on Aspen Plus process simulation results to find energy-using bottlenecks. Based on the simulation results, the corresponding energy-saving methods are proposed. With optimization of pumparound ratio of the main fractionator, high-temperature heat recovery of the pump around stream is improved. Total exergy has been increased from 32.71 MW to 34.03 MW, and exergy efficiency of the fractionation process improved 4.0%. Optimization of the heat exchanger network has resulted in 13.4 t/h more 3.5 MPa steam and 11 t/h more 1.0 MPa steam in the FCC unit. In addition, about 0.81 MW high-temperature heat is recovered from the slurry product. Low-temperature heat recovery increases 2.91 MW, and the exergy increased from 24.83 MW to 27.70 MW. Compared with the original process, the exergy efficiency of the heat exchanger network improves 11.5%.