Experimental evaluation of scattering phase function and optimization of radiation absorption in solar photocatalytic reactors

Radiation absorption in photocatalytic reactors is usually simulated using the Monte Carlo (MC) stochastic method. In this article, MC is coupled with three different scattering phase functions: isotropic (ISO) phase function, diffuse reflecting large sphere (DR) phase function and Henyey–Greenstein (HG) phase function. Here, the model accuracy is examined via adequate experiments. The results show that phase function plays an important role in MC method. HG phase function is superior to ISO and DR phase functions because of small errors (less than 5%), and the value of the characteristic parameter g should be 0.64. The simulate results show that the absorption of solar radiation relates strongly to geometry configuration of reactors and catalyst concentration. The solar surface uniform concentrator (SUC) has a 9.94 times higher radiation absorption than the tubular reactor and realizes a uniform radiation distribution. The optimal catalyst concentrations of the SUC and the tubular reactor are 0.53 g/L and 0.68 g/L respectively.