Study on adsorption of NOx/SO₂ with coconut shell activated carbon in simulated flue gas

Abstract

Abstract Adsorption is used to simultaneously remove SO2 and NOx from flue gas because of its easy operation, low energy consumption and easy practical application. In this paper, coconut shell activated carbon (AC) was used as the adsorption matrix for simultaneous desulfurization and denitrification. The AC was modified and characterized using a physical followed by chemical approach, and orthogonal tests were designed to conduct experiments on the simultaneous adsorption of SO2 and NOx from modified activated carbon in simulated flue gas. The adsorption experiments showed that the modified coconut shell AC had high-performance adsorbent conditions for the simultaneous removal of SO2 and NOx. The optimal modification conditions were as follows: the physical pore size of the AC was adjusted in an air atmosphere at 400°C for 2h, then modified by reduction in 3% KOH solution, followed by impregnation using 6% cerium nitrate solution, respectively. When the minimum concentration of SO2 in flue gas is 1000ppm and the minimum adsorption temperature is 50℃, its average desulfurization and denitrification efficiency can reach more than 95% and 40% respectively. As an excellent adsorbent, coconut shell AC has good application prospects for simultaneous desulfurization and denitrification of flue gas.