Thermally autonomous microchannel reactor to produce hydrogen in steam reforming of methanol

A thermally autonomous microchannel reactor (AMR) for production of hydrogen in the steam reforming of methanol has been designed and tested. The reactor consists of an evaporator, a stirrer, and a microchannel catalytic unit (MCU) containing a catalyst deposited in short channels (10 mm in length and 1 mm in diameter). The MCU design makes it possible to conduct simultaneously endothermic and exothermic processes. The heat produced in the total oxidation of methanol is consumed for the heating of the reaction mixture and maintaining the steam reforming of methanol. A CFD simulation of hydrodynamic and thermal processes based on chemical reactions proceeding in the MCU channels showed that a temperature gradient in the reaction zone does not exceed 2 °С. The simulation results agree fairly well with experimental data. A maximum efficiency of the AMR is achieved at temperatures 260-290 °С and at a feed rate of the water-methanol mixture FMeOH0=10mmol/min. Under these conditions, the overall efficiency of AMR is maximal and equals 57%, and the hydrogen production rate achieves 30.6 L/h at the methanol conversion of 82%.