Application of microwave technology in desulfurization of flue gas by activated carbon
微波辐照技术在活性炭脱硫中的应用

Coal-based activated carbon (AC) is treated in a flow of N2 gas by a microwave-heating device instead of a conventional furnace in order to increase the SO2 adsorption capacity on the activated carbon. The influences of different modification conditions, such as microwave power, radiation time and particle diameter, on desulfurization capability are studied. The optimal modification condition is found. At the optimal condition, the adsorption and catalysis ability for SO2 on the treated AC and the untreated AC is compared. The result shows that the treated AC has better SO2 adsorption and catalysis ability. The mechanism on microwave treatment for modification of AC and on SO2 adsorption and catalysis ability is discussed based on nitrogen adsorption, XPS and element analysis, and pH measurement. During microwave treatment, the surface area and porous structure of treated AC have not changed remarkably, and most oxygen-containing groups are decomposed from the surface of the carbon, which in turn gives rise to a relative increase in the pH value of the carbon. Only a few minutes are required to decrease oxygen content and increase nitrogen content in carbon. Consequentially.