FCC汽油加氢脱硫过程的热力学分析

Thermodynamic Analysis of Hydrodesulfurization Process of FCC Gasoline

建立了模拟FCC汽油加氢脱硫反应的化学平衡模型。该模型含有21个组分和12个独立的化学反应。利用基团贡献法估算了各组分的热力学数据,并进而获得了各反应的化学平衡常数。用改进的牛顿迭代法得到了不同温度、压力、进料H2/Oil比条件下的体系平衡组成并考察了反应条件对体系平衡组成的影响。热力学分析结果表明,高温、低压和低H2/Oil比在一定程度上可以降低烯烃饱和的趋势;低温、高H2/Oil比则有利于抑制硫醇的生成。模拟结果可为选择FCC汽油加氢脱硫过程的工艺条件提供参考。

A chemical equilibrium model about hydrodesulphurization reaction of FCC gasoline,which contains 12 independent chemical reactions and 21 components,has been put forward.Thermodynamic data of all components are calculated using the group contribution method and equilibrium constants of the reactions are also obtained.Equilibrium compositions of the reaction system at different temperatures,pressures and H2/Oil ratios are computed by means of the modified Newton's iteration technique,and the effects of reaction conditions on equilibrium compositions of the reaction system are analyzed.The thermodynamic analysis results show that high temperature,low pressure and low H2/Oil ratio can lessen olefin saturation tendency;otherwise,low temperature and high H2/Oil ratio are benefit to inhibit thiol generation.Simulative results are useful for selecting hydrodesulphurization process conditions of FCC gasoline.