Multiphase Reactors in Solar-Assisted Fuel and Chemical Production

The utilization of multiphase reactors has been prevalent in various industrial applications due to their capacity to enhance heat and mass transfer, achieve high reaction conversion rates, and exhibit a high degree of reaction flexibility. Considering the growing need for sustainable solutions in the global industrial sector, there is an increasing interest in the utilization of solar energy to drive multiphase reactors. In this regard, this study presents numerical investigations of two types of multiphase reactors that are suited for solar-assisted fuel and chemical production. These include (i) a gas-liquid multiphase photobioreactor for microalgae cultivation operating at room temperature, and (ii) a gas-solid fluidized-bed reactor for solar-driven biomass gasification at approximately 900°C. Transient multiphase computational fluid dynamics (CFD) models were developed and validated against experimental results to study the gas-liquid bubbly flow in the photobioreactors and the gas-solid bubbling fluidization flow in the biomass reactor, respectively. The CFD model was further coupled with heat transfer, solar radiation transport, growth kinetics of microalgae, and biomass gasification kinetics to provide an accurate and comprehensive prediction of the complex multiphysics processes.