甲醇POSR制氢的反应网络热力学分析和有效因子的估算

Hydrogen production by partial oxidation steam reforming of methanol over a Cu/ZnO/Al2O3 catalyst has been paid more and more attention. In order to optimize the operation conditions and improve the catalysts used in the methanol partial oxidation steam reform reaction, the mechanisms of the reaction in a tubular reactor are analyzed. The heat effects, reaction equilibrium constants for different reactions in this system and equilibrium compositions at corresponding reaction temperatures are investigated. By these analyses, thermodynamic competitive abilities for these reactions may be understood. The kinetic expressions for partial oxidation of methanol, steam reforming of methanol, decomposition of methanol and water gas shift reaction are evaluated. These kinetics can be used in the design of the reactor and the optimum of the operation conditions. From the basic concept of the effectiveness factors, the intraparticle diffusion limitations were taken into account. The effectiveness factor for each reaction along the bed length is calculated. It describes the difference between the real reaction rate inside the catalyst pellets and the intrinsic reaction rate in the bulk phase along the reactor bed length in the reaction temperature range.