Abstract: MIP (maximizing iso-paraffins process) process utilizes the technique of linking two reaction zones in series, and hence effectively improves gasoline quality.Cold simulation of MIP reactors can reveal the flow structures in the second reaction zone and also the effects of geometrical structures, but cannot provide the changes in hydrodynamics resulting from catalytic cracking reactions.To capture these changes, this work aimed at carrying out three-dimensional simulation of the MIP reactor by considering the reactions.The simulation was based on the two-fluid model and 12-lump kinetic model.The inter-phase momentum transfer and heat transfer models took into account the effects of multi-scale flow structures, and were compared with the traditional models based on homogeneous state.The simulation found that the multi-scale models could reasonably predict the flow structures and solids volume fraction in the second reaction zone as well as the temperature profiles, compared to the traditional model.For predicting product yields, both models showed similar results.They had good predictions in slurry and diesel, but fail to predict LPG and dry gas.The above finding implied that the effects of multi-scale structures should not only be considered in the momentum transfer and heat transfer models, but also be taken into account in the lumped kinetic model.

Key words: simulation, multi-scale model, EMMS, lumped reaction kinetics, two-fluid model

摘要： MIP(maximizing iso-paraffins process)工艺采用两个反应器串联技术,可有效改善汽油质量。MIP反应器的冷态模拟虽能揭示反应器内的流动行为及几何结构的影响,但无法考虑反应引发的变化。为更准确地揭示该反应器中的油气及颗粒运动行为,尝试了三维瞬态反应模拟。模拟采用双流体模型结合十二集总反应动力学模型,并在相间动量传递模型和传热模型中考虑了多尺度结构的影响,然后与基于均匀分布的传统模型作对比。结果表明,相比于传统模型,多尺度模型能较准确预测二反段内的流动结构、颗粒浓度以及温度分布。在预测产率方面,两种模型所得结果类似,都对油浆和柴油的预测较好,对液化气和干气的预测偏差较大。这说明,仅在动量传递及传热模型中考虑多尺度结构的影响是不够的。

关键词: 模拟, 多尺度模型, EMMS, 集总反应动力学, 双流体模型