CFD optimization for the performance of a catalytic cracking industrial riser flow and reaction on the gasoline production

摘要

流体催化裂化(FCC)提升管反应器用于炼油转化过程，将重油转化为轻质副产物用于交通燃料和石化产品。但是，提升管反应器内的复杂流体流动和反应为完全控制其性能提供了障碍。因此，为了改善其在汽油和其他产品生产中的性能，需要对这种反应器进行新的建模和仿真以进行优化。然而，催化剂分布对提升管反应器的研究是其难点之一。
　　另一方面，研究实验室开发的模型变得越来越完整和高效，并且电脑的计算性能不断提升，这些使设想中这种模拟成为可能。因此，数值模拟已经成为现有工业流程开发和优化的不可或缺的预测指标。
　　本研究的目的是使用商业计算流体动力学(CFD)软件预测生产工艺中的流体动力学行为和反应。在二维模拟中使用两阶段流模型及五集总动力学模型以表征汽油和其他副产物生成的FCC裂化过程。边界条件取决于本研究的目标，即提高提升管反应器在汽油生产中的性能。
　　由于颗粒分布沿着提升管发展不均匀，因此提出了双侧催化剂入口提升管反应器以改善它们的分布，较之于单侧催化剂入口反应器，反应的预期效果有着显著改善。在反应器中，还考虑了由于气体体积膨胀导致的流速上升。对反应的进行中提升管内部的动量和热量传递还做了详细的分析讨论。两相流的表征使用欧拉方法来完成。使用的CFD软件为FLUENT14.5，计算获得了设计的反应器中汽油的产率。

目录

声明

ABSTRACT

摘要

Table of Contents

Nomenclature

Chapter 1 Introduction and literature survey

1．1 Introduction

1．2 Generalities on refining

1．2．1 Fluid Catalytic Cracking(FCC)

1．2．2 The Fluidized Beds

1．3 Gas-particle flow transport approach

1．3．2 Drag coefficient in a gas-particle flow

1．3．3 Heat transfers in gas-particle flow of dense regime

1．3．4 Justification of the correlations used in this CFD simulation

1．4 Modeling of the fluid catalytic cracking reaction

1．4．1 Description

1．4．2 Catalytic cracking models

1．4．3 Comparison and sensitivity of different models

1．5 Gas-particle flow in FCC riser reactor

1．6 Summary

Chapter 2 Mathematical modeling of reactive multiphase flow in riser reactor

2．1．1 Model Assumptions

2．2 Mathematical model of reactive two-phase flow in riser reactor

2．2．1 Governing equations

2．2．2 Constitutive equations

2．2．3 Turbulence modeling

2．2．4 Continuity equations for reactive components

2．3 Summary

Chapter 3 Simulation methodology of the two industrial riser reactors

3．1 The riser reactors considered

3．1．1 Process description of the riser reactors simulated

3．1．2 Meshing

3．1．3 Phases in presence and their properties

3．2 Operating point

3．2．1 Kinetic reactions of the process

3．2．2 Numerical aspects

3．2．3 Initial and boundary conditions

3．2．4 Simulation procedure

3．3 Validation of the simulation methodology

3．4 Summary

Chapter 4 Simulations results and discussion

4．1 Convergence of results

4．2 Reactive biphasic simulation results of the one-sided riser reactor

4．2．1 Hydrodynamic effects

4．2．2 Effect of the gas phase velocity on the catalyst distribution

4．3 Effects of the two-sided catalyst inlets

4．3．1 Module vector on the injection zone and particle distribution

4．4 Comparison between case 1 and case 2

4．5 Summary

Chapter 5 Conclusion and recommendations

5．1 Conclusion

5-1 Recommendations

References

Publications

Acknowledgments

Author’s resume

Supervisor’s resume