丙烯腈流化床反应器性能的模拟优化

针对中国石油化工股份有限公司齐鲁分公司腈纶厂丙烯腈装置应用新技术改造后,反应器性能发生较大变化,丙烯腈收率达不到设计值的情况,建立了多釜串反应器模型,利用该模型对操作参数进行优化,分析了反应器性能出现异常的可能原因,并制订了相应措施。模拟结果表明,该模型基本反映了床层中的传递和反应特性,可用于反应器模拟和分析。利用该模型得到的优化操作参数为:氨气与丙烯的摩尔比1.12～1.15、空气与丙烯的摩尔比9.5～10.0、操作压力0.145～0.155 MPa、操作温度435～445℃。技术改造后反应器性能发生较大变化的主要原因是扩能幅度太大,催化剂装填量增加,总进气量增加,造成床层偏高,深度氧化加剧。在调整了反应器的操作参数及采取降低投料负荷、减少催化剂装填量、反应器上部高出换热管的部分设简易内构件等措施后,丙烯腈收率一直保持在较好水平。

Simulation and Optimization of Acrylonitrile Fluid Bed Reactor

After the revamp of Qilu acrylonitfile plant, the increase of plant capacity led to increases of the catalyst loading amount and feedstock flowrate. The bed height rose and deep oxidation obviously took place. Acryonitrile yield from the original reactor could not meet the design value. Aiming at optimizing the operation of reactor system in question, a consecutive multi-reactor model of simulation was established. Simulation showed that the model can essentially describe the reaction, and heat and mass transfer characteristics in the bed. Optimal operating parameters obtained by using the established model were as follows:n(NH_3) : n(C_3~=) 1. 12 - 1. 15, n(air) : n(C_3~=) 9.5 - 10.0, pressure 0.145 -0.155 MPa, temperature 435 -445 ℃. By adjusting the operating parameters of the reactor system according to the simulation, measures were taken to reduce catalyst loading amount and feedstock load at reactor inlet, to set simple inner component at upper part of reactor higher than the heat exchanger tubes for releasing the heat from the part. So the acrylonitrile yield remained at the required level.