An integrated modeling method for membrane reactors and optimization study of operating conditions

This study proposes an integrated membrane reactor modeling method based on thermodynamic equilibrium to investigate the enhancement potential of membrane reactors relative to original reactors. The modeling method is implemented by MATLAB codes, where local reaction equilibrium is calculated by the minimum Gibbs free energy principle, and product separation is determined by iterative convergence. Combined with the developed and validated methane membrane reforming reactor model, the reaction operating conditions are parametrically analyzed and optimized by GA and NSGA-II. The results show that pressure-driven hydrogen recovery enhancement is the key to improving membrane reactor performance. The reference reaction conditions given by the NSGA-II decision method are similar to those given by GA, concentrated in a temperature range of 702.5-952.0 K, a pressure range of 805.7-1077.8 kPa, and a steam-to-methane ratio range of 1.2-9.9. The membrane reactor has the potential to achieve a hydrogen yield ratio of 4.0 and an outlet hydrogen molar fraction of 79.7% simultaneously at low temperature and high pressure, which is unachievable in the original reactor. Furthermore, the Pareto solution set of reactor performance obtained by NSGA-II provides the reference for the theoretical design of reactors and their systems.