The Study On Application Of Microwave Technology In Activated Carbon For Flue Gas Desulfurization

The behavior of activated carbon's temperature increasing in the field of microwave, the modification of activated carbon(AC) by microwave heating and its adsorption capability of SO2, the desorption of SO2 from AC by microwave are investigated in a bench scale.Experimental results show that AC can strongly absorb and fully use microwave energy and its temperature will increase rapidly and reach the maximum after 180 seconds. The temperature rising process of the AC in microwave's field can be divided into three steps: linearity rise step, logarithm rise step and stability step. The order of degree that the investigated factors affects the AC's temperature changing is: input power of microwave>>heating time>carrier gas volume flux>>activated carbon weight. Moreover, the higher the microwave power is, the quicker the AC's temperature increase and the higher the temperature's maximum is. On the other hand, smaller N2 volume flux is benefit to AC's temperature-rising. Comparatively, activated carbon weight is not so much important as far as AC's temperature changing process is concerned.The desulfurization capability of modified activated carbon by microwave is higher than that of original one ranging from 144.3% to 288.0%. The change of porous texture of Modified AC by microwave is not so much obvious compared with original one, while the quantity of surface basic functional groups and Nitrogen elements of modified AC is much more than original one.The process of desorption and reclamation of SO2 from activated carbon is so rapid that the AC' regeneration could be nearly completed within 570 seconds. The maximal volume content of SO2 in carrier gas (N2) and the maximal mass reclamation ratio of sulfur dioxide is about 25% and 99.7% respectively. Increasing input microwave power benefits obtaining higher volume content of SO2 and more mass ratio of reclaimed SO2, and decreasing N2 volume flux benefits attaining higher volume content of SO2 but is not good as to the reclamation of SO2 Comparatively, the influence of AC's weight on the desorption and reclamation of SO2 is very little. The order of degree that those factors affects the reclamation ratio of SO2 is: reaction time > carrier gas volume flux > power of microwave >activated carbon weight.The desorption process of sulfur dioxide from activated carbon by microwave promotion accords with the first order kinetics model, and the rate constant raises logarithmically with the increase of microwave power and exponentially with the carrier gas volume.