Mathematical modelling of the solar-driven steam reforming of methanol for a solar thermochemical micro-fluidized bed reformer: thermal performance and thermochemical conversion

A solar thermochemical reformer/receiver which combines a ST-μFB reformer and a catalytic bed of micro-sized particles offers a novel approach for the solar-driven catalytic steam reforming of methanol (SDCSR-MeOH) method. Heat transfer, mass transfer and solar thermochemical conversion performance have a great significance on the SDCSR-MeOH method due to high interfacial absorption surface of micro-sized particles. The solar radiation has been coupled to the ST-μFB reformer as a novel driving energy for conducting the endothermic reactions of methanol (CH3OH) inside ST-μFB reformer to produce solar H2. Solar H2 had won an important role as renewable feedstocks for different chemical processes and particularly in fuel cells applications. A non-isothermal mathematical model was described by a set of partial differential equations (PDEs) that couples to a complex kinetic model of the SDCSR-MeOH employing the Cu/ZnO/Al2O3 catalyst. The system of novel PDEs has been transformed into simpler system of ordinary differential equations using the coupled integral equation approach. Validation results demonstrate that the two validated cases for the reaction temperature against the simulated results by authors had reached a good fit as well as the solar thermochemical conversion of CH3OH. The temperature profiles of the gas phase, solid phase and ST-μFB reformer wall were simulated at three different positions from ST-μFB reformer. The reactant and product distributions inside ST-μFB reformer were analysed at two different reaction temperatures. The effect of the reaction temperature was studied on the conversion of CH3OH and yield of H2. In addition, the action of the weight hourly space velocity has been analysed on the conversion of CH3OH.