A novel waste heat-driven methane reforming membrane reactor and parametric optimization study combining CFD simulation and response surface methodology

High-temperature waste gas can drive the methane reforming reaction to produce hydrogen; however, existing reactors suffer from significant heat and mass transfer resistance and inefficient operating parameter configurations. To address these challenges, a novel composite membrane reactor was proposed in this study, with operating parameters optimized using the response surface methodology (RSM). A multi-physics coupling model of the reactor was developed through computational fluid dynamics (CFD) simulations. A comparable study demonstrated that the novel reactor significantly outperforms the traditional double-tube reactor, achieving an improvement of up to 15.88 % in waste heat utilization efficiency. Single-factor experiments showed that the effects of key operating parameters on methane conversion (X_CH4), hydrogen yield (Y_H2), and waste heat utilization efficiency (η) vary significantly. Then the Plackett-Burman (PB) experiment was employed to screen the three most important influencing factors, which were used as input variables for the Box-Behnken Design (BBD) experiment. A quadratic polynomial was fitted to describe the relationship between the input and output variables, where the R² values for the expressions of X_CH4, Y_H2, and η were all above 0.99. The optimal operating parameters that simultaneously maximize X_CH4, Y_H2, and η were obtained, where X_CH4, Y_H2, and η were 99.83%, 86.37%, and 39.07%, respectively. This study improved the performance of a methane reforming reactor with waste heat recovery through structural design and operational parameter optimization.