Distribution characteristics of salt crystals in a supercritical water fluidized bed reactor with CFD-PBM coupled model

Supercritical water gasification (SCWG) is a promising method for converting organic waste into hydrogen. However, salt deposition problems seriously hinder the development of hydrogen production from high-salt organic waste in the supercritical water fluidized bed reactor (SCWFBR). This work investigates the distribution characteristics of salt crystals in supercritical water (SCW) by using computational fluid dynamics coupled with population balance model (CFD-PBM). The proposed model is proved to be useful in simulating the nucleation and growth processes of sodium chloride in the SCWFBR. Sodium chloride crystals are concentrated near the nozzle, and crystal mean diameter increases with increasing the mass flow rate of sodium chloride solution and decreasing the mass flow rate of SCW. Crystal size in the SCWFBR can be controlled by adjusting the mass flow rates of salt solution and SCW. The obtained results provide a theoretical basis for the SCWG of high-salt organic waste.