Photocatalytic hydrogen production from refinery gas over a fluidized-bed reactor I: Numerical simulation

Photocatalytic technology has received increasing attention owing to its various advantages. In this work, we designed a fluidized-bed photocatalytic reactor using H₂S simultaneously as the bubbling gas for catalyst suspension and as the feed for hydrogen production. The photocatalyst distribution was simulated by CFD with a Eulerian model. The simulation results indicated that the fluidizing time showed a linear relationship with the inlet gas velocity and that the optimal inlet gas velocity was between 30 and 50 mL/min. Further, light energy absorption characteristics, in both homogeneous and heterogeneous media, were simulated by the Monte Carlo method. Our study showed that light energy absorption is affected by the nonuniform distribution of the catalyst particles and that finding the optimum optical thickness in chemical reaction space and the optimal height for catalyst fluidization is essential for reactor design. The simulation results and the related predictions are helpful for the design and optimization of fluidized-bed photocatalytic reactors.