Experimental study on water recovery and SO 2 permeability of ceramic membranes with different pore sizes

Abstract

In this study, the water recovery performance from flue gas with ceramic membrane tubes of different pore sizes 30, 50, and 200 nm was experimentally studied. The effects of flue gas temperature, flue gas flow rate, water coolant temperature, and water coolant flow rate on the water recovery performance were analyzed. In addition, in the experimental study of SO2 permeability, the pH of the water coolant inlet and outlet was measured using a pH meter to analyze the SO2 permeability of ceramic membranes during the water recovery process. The results show that the water recovery performance of the 50 nm pore size ceramic membrane is better than that of the other two types of ceramic membrane in most cases. The maximum amount of reclaimed water and the highest water recovery rate are 4.82 kg/(m2·h) and 80.3%, respectively. Under the same SO2 concentration condition, the SO2 permeation flux of the 30 nm pore size ceramic membrane is smallest, and that of the 200 nm membrane is the largest. When the SO2/N2 mixed gas flow rate is 6 L/min, the SO2 permeation flux of the 30 and 200 nm membranes is 0.407 and 0.635 mmol/(m2·h), respectively. The ceramic membrane with smaller pore size can block more SO2 permeation, while the ceramic membrane with larger pore size can remove SO2 better.