提升管轴向流动和重油催化裂解反应过程数值模拟

Numerical Simulation of Axial Flow and Catalytic Pyrolysis Process of Heary Oil in a Riser Reactor

基于欧拉-欧拉双流体模型,采用重油催化裂解的11集总模型,建立了实验室小型提升管重油催化裂解流动-反应的二维模型。比较了气-固两相冷态流场和有催化反应流场,以及二维流动反应模型和0.5维模型下的轴向产品分布。结果表明,冷态流场和有催化反应时流场轴向气固相速度和颗粒浓度都存在明显差异,说明一个完备的反应器模型必须充分考虑反应与流动、传递之间的相互影响;提升管内轴向非均匀性使得二维和0.5维模型下轴向重油转化率和产品收率分布存在明显差异,对于重油转化率,柴油和汽油产率,这种差异在提升管中下部更为显著,比较提升管出口产品组成发现,二维模型结果与实验结果吻合更好。

Based on the Euler-Euler two fluid model, was derived to simulate the heavy oil catalytic pyrolysis a two-dimension flow-reaction coupling model in a laboratory small-scale riser reactor using gas-solid two-phase flow model and the 11-lumps kinetic model. The difference of the flow patterns between cold flow model and flow-reaction coupling model, as well as the axial product distribution between the two-dimension flow-reaction coupling model and the half-dimension model were compared. The simulation results showed a huge difference in the gas-solid velocity and solid density between cold flow model and flow-reaction coupling model, which indicated that the effect of reaction on flow and transfer pattern must be taken into consideration for a commercial riser. Due to the axial heterogeneity, the obvious difference was observed in the axial product distribution between the two-dimension model and the half-dimension model, especially for heavy oil conversion, diesel oil and gasoline yield. Comparing the riser outlet product component of the two-dimension model and the half-dimension model with the experimental results, it showed that the results of two-dimension model agree better with the experimental results.