Steady and dynamic state simulation of a methanol continuous-flow laboratory reactor for process variable evaluation and event-based thermostat regulation

Abstract

Power-to-X (P2X) converts excess renewable energy into hydrogen and then renewable fuels like methanol, addressing hydrogen storage costs. Methanol synthesis uses catalysts such as Cu/ZnO/Al2O3, with performance influenced by pressure, hydrogen-to-carbon ratio, and temperature. Therefore, accurate modelling, using kinetics like Graaf et al. Langmuir-Hinshelwood-Hougen-Watson type model, material, momentum, and energy balances within the reactor, is essential. Based on these models, the performance of methanol synthesis was analysed. Specifically, analysis of bed porosity (ε<inf>pm</inf> = 0.1 – 0.5), stoichiometric ratio of hydrogen-to-carbon (SH = 1 – 3), Gas-Hourly-Space-Velocity (GHSV = 1400 – 8400 h−1), temperature (200 – 280 °C) and pressure (20 – 60 bar) on the methanol synthesis performance for both dynamic and steady-state conditions was performed via COMSOL Multiphysics. This was followed by a thermostatic regulation of the reaction temperature between 239 – 241 °C, model application to simulate an in-house laboratory digital twin Micromeritics reactor, in addition to an industrial-sized reactor.