Optimization of radiation absorption model in solar photocatalytic reactors: Coupling photocatalyst concentration distribution

Practical and accurate radiation absorption model is crucial in designing and scaling-up the photocatalytic reactor, and usually established using the Monte Carlo (MC) stochastic method. In this study, the MC method is optimized by coupling photocatalyst concentration distribution. The new model takes into account the effect of the photocatalyst concentration distribution on the radiation absorption and is called MC coupled model. Here, the radiation absorption test system is established to examine the model accuracy. The results show that the photocatalyst concentration distribution has an important impact on the simulation. The MC coupled model is superior to the MC model due to smaller errors and suitable for the simulation of radiation absorption. Radiation absorption is related to the photocatalyst concentration and the flow velocity of the mixed fluid. As the flow velocity increases, the location where the maximum of photon absorption occurs gradually moves upward and the maximum becomes larger. The optimum photocatalytic concentration of photocatalytic system is 0.30 g/L. Based on the MC coupled model, the general radiation absorption research method of photocatalytic systems is proposed.