Biomass and Coal Modification to Prepare Activated Coke for Desulfurization and Denitrification

Abstract

SO2 and NOx in flue gas are serious environmental pollutants. As an excellent adsorbent, activated coke has good application potential in flue gas desulfurization and denitrification. In this study, different concentrations of NH3 and K2CO3 solutions were used to modify the activated coke made from biomass and coal, and then separate and coordinated desulfurization and denitrification experiments were carried out. The adsorption efficiency of activated coke and the adsorption capacity of SO2 and NO were compared, and the adsorption relationship between SO2 and NO was clarified. The changes of the surface functional groups of activated coke before and after adsorption and the forms of SO2 and NO after adsorption were analyzed by Fourier transform infrared spectrometer and X-ray diffractometer patterns. Results show that K2CO3 and NH3 modification can promote the adsorption of SO2 and NO in activated coke, and K2CO3 modification is more significant for improving the denitrification and desulfurization capacity. When the unmodified activated coke synergistically adsorbs SO2 and NO, there is a competitive adsorption between NO and SO2. However, when the activated coke modified with K2CO3 solution and NH3 synergistically adsorbs SO2 and NO, both have a promoting effect. After the adsorption of NH3-modified activated coke, CaSO4 and Na2SO4 crystals will appear. K2SO4 will exist after the adsorption of activated coke modified with K2CO3 solution.