Numerical modelling for the solar driven bi-reforming of methane for the production of syngas in a solar thermochemical micro-packed bed reactor

Abstract

High temperature heat transfer and thermochemical storage performances of the solar driven bi-reforming of methane (SDSCB-RM) in a solar thermochemical micro-packed bed (ST-μPB) reactor are numerically investigated under different operating conditions along ST-μPB reactor length. A pseudo-homogeneous mathematical model is developed to simulate the heat and mass transfer processes coupled with thermochemical reaction kinetics in ST-μPB reactor with radiative heat loss. The effect of several parameters including the gas flow rate (Qg), effective thermal conductivity (λs,eff), operating time (ti) and operating temperature (Top.) were investigated. The simulated results shown that the pressure drop increases with the increase of Qg. When the Qg is increased, the temperature profiles at the surface of the solid phase as well as the temperature profiles of the gas phase are remarkably decreasing. The consumption of reactants (CH4, H2O and CO2) is increased when the λs,eff is gradually increased. On the other hand, the production of products (H2, and CO) is remarkably increasing with the increase of the λs,eff. According to simulated results, the overall conversions of reactants (CH4 and CO2) and the dimensionless flow rate (DFR) of H2 reach the maximum values of 98.18%, 75.61% and 1.6278 at the operating time of 2.50 h. The thermochemical energy storage efficiency (ηChem) remarkably increases with the operating temperature and the maximum value of the ηChem can be as high as 74.21% at 1123 K. The overall conversions of reactants (CH4 and CO2), DFR of H2 and the energy stored as chemical enthalpy (QChem) were also evaluated in relation to the operating temperature and their maximum values of 99.43%, 89.03%, 1.6383 and 1.3745 kJ/s are obtained at 1225 K.