Preparation and SO2 Adsorption Behavior of Coconut Shell——Based Activated Carbon via Microwave-Assisted Oxidant Activation

A series of oxidants supported on coconut shell-based activated carbon(CAC) through microwave irradiation were prepared and characterized using scanning electron microscopy(SEM), Nadsorption/desorption analysis, and X-ray photoelectron spectroscopy(XPS). The SOadsorption capacities and rates were evaluated by adsorption tests performed in a fixed bed reactor with a simulated flue gas, and the adsorption isotherm models were validated against the experimental results. The findings revealed that the SOadsorption capacity decreased in the following order: MW-KCrO-CAC > MWKMnO-CAC > MW-HO-CAC > MW-CAC. The SOadsorption capacities and adsorption rates of the samples increased with an increasing oxidizability of the oxidants owing to the increment of mean pore size and oxygen-containing functional groups. In addition, a high initial SOconcentration and a low bed temperature could positively affect the SO2 adsorption. Finally, the Langmuir model validated that SOwas mainly adsorbed through chemical adsorption on the sample surfaces.