Numerical Simulation of a Transpiring Wall Reactor

Supercritical water oxidation has a promising future in treating organic wastewater with high toxicity, high concentration and bio-refractory properties. However, the reactor corrosion and salt deposition problems have severely hindered its commercial application and development. Transpiring wall reactor can effectively overcome these two problems via forming a protective transpiration water film on its inner surface, which has become a focused development direction in supercritical water oxidation. In this work, the temperature and velocity distributions in a transpiring wall reactor are simulated by a commercial Fluent Software 6.3 under the conditions of the feedstock temperature of 693 K, the oxidation coefficient of 1.5, the pore density of the transpiring wall of 20%, and the methanol concentration of 3 wt% or 5 wt%. According to the simulation results, we can optimize the reactor configuration by shortening the length of the center pipe, prolonging the distance between the reactor bottom outlet and the spout, increasing the pore density of the transpiring wall bottom, and/or decreasing its top pore density. The results are expected to theoretically guide the optimization design and reliable operations of the transpiring wall reactor.