Two-Dimensional Model of a Dual-Ring Radial Reactor for Long-Chain Alkane Dehydrogenation

This study focuses on the long-chain alkane dehydrogenation (LADH) process in a dual-ring radial reactor. By integration of the Ergun equation, continuity equation, and an 18-lumped kinetic model of LADH, a two-dimensional flow reaction model for the dual-ring radial reactor is established. The Sequential Quadratic Programming (SQP) algorithm is employed to determine the boundary pressure of the catalyst bed, facilitating the acquisition of the velocity, pressure, temperature, and concentration distributions within the reactor. Through iterative calculations of the fluid mechanics and kinetic models, the catalyst utilization efficiency and its influence on the product yield and selectivity are analyzed. The model validation results show good agreement between the simulated and industrial data, with a relative error of 5.50% for the calculated temperature drop and 2.57% for the calculated pressure drop. The relative error of the conversion is 1.18% and the relative error of selectivity is 2.75%. The influences of the catalyst bed height, the catalyst seal height, and the feed composition on the performance of the reactor were investigated, revealing that excessive height of the catalyst sealing section can lead to catalyst waste. This research provides a theoretical basis and technical support for the design of radial reactors.