Studies Of Sulfur Dioxide Adsorption On The Modified Activated Carbon By Microwave

Flue Gas Desulfurization by activated carbon (AC) is a craft with high efficiency and resource utilization, which can not only control SOa pollution, but also reclaim and reuse sulfur resource, and is an important desulfurization method currently. This paper presents a new method of modifying activated carbon using a microwave device as a heat source to increase the SO2 adsorption capacity on the modified activated carbon (WAC) for the first time. WAC is compared with AC on SO2 adsorption ability, and the dynamical adsorption experiment of SO2 on WAC is carried out. Then, the modification mechanism is discussed by the way of nitrogen gas adsorption instrument, X-ray analysis instrument, SEM and XPS, etc.In microwave field, temperature rising of AC is related to microwave energy input, and temperature rising behavior is decided by microwave power mainly. The quantity of AC and N2 gas speed do little effect on temperature rising behavior of AC. Wasting ratio of AC quantity is increased, when microwave power is higher, the quantity of AC is decreased and NI gas speed is lower.By orthogonal experiment, the connections between desulfurization effect and Influencing factors: power of microwave, radiation time and particles diameter is studied. The result shows that the SO2 adsorption capacity on WAC is increased greatly, and the highest quantity of SO2 adsorption is 109.4mg/g, and power of microwave and particles diameter are the key factors to decide desulfurization characteristic on WAC; the iodine numbers of WAC are also higher than that of AC, and power of microwave and radiation time are the key factors to decide the iodinenumber. Under well-controlled conditions, the adsorption capacity on WAC is better, when the power of microwave is higher, radiation time is prolonged and particles diameter is smaller.The dynamical adsorption experiment of SO2 on WAC indicates that the desulfurization performance of WAC is better than that of AC, no matter what kind of operation system; under "SO2-N2-O2" system, desulfurization efficiency of WAC is increased, when the inlet concentration of SO2 and gas speed is lower, and the reaction temperature is higher and water vapor joins; apparent active energy of SO2 adsorption on WAC (microwave power is 340W, radiation time is 1 min) is -13.358KJ/mol, under "0.12%SO2-N2" system. When WAC is regenerated by microwave heating after adsorbing SO2, its desulfurization effect has not reduced evidently and the WAC regenerated for four times still has higher SO2 adsorption capability than AC.The mechanism of influencing the SO2 adsorption and catalysis characteristic on WAC is that microcosmic appearance of WAC is changed greatly, most oxygen-containing groups are removed from AC, a relatively low oxygen content is gained, basic character enhances, this in turn gives rise to an increase in the pH value of WAC, the quantity of nitrogen content is increase, surface active sites of absorbing SO2 on WAC are increased, apparent active energy of SO2 adsorption on WAC is reduced, after modified by microwave heat.