Mixing and chemical reaction in tubular reactors and stirred tanks

Abstract

Fluid flow patterns and turbulence levels are instrumental in determining chemical reactor performance. Parameters such as stirrer type and size, fluid physical properties, chemical species concentrations and flow rates can strongly influence the safety, efficiency and reliability of reactors, with consequent cost implications. In this project, Computational Fluid Dynamics has been used to obtain insight into the characteristics of tubular and stirred tank chemical reactors. Attention is focused on single phase liquid isothermal turbulent flows. Turbulence theory is used to select and develop appropriate physical models for both fluid flow and chemical reaction rates. Many previously used models are shown to be of limited validity. Results of simulations are compared with experimental measurements of the flow field and progress of both simple and complex chemical reactions. Comparisons are generally favourable. Limitations of the present approach are highlighted and future refinements and extensions suggested.