Regeneration Of Activated Carbon Loading The Toluene By Microwave Radiation

Activated carbon has good opening structure and huge surface area, it has excellent absorption capacity and had got wide application in industry. Since the first application of grain AC in industrial waste water treatment and waste air treatment in 1970s, AC has got great development in terms of technique and has been employed for different purposes. Meanwhile, a lot of waste saturated adsorbing AC have been produced in the process of its application, it not only wastes resources, but pollutes the environment if it were not reclaimed and disposed correctly.As microwave heating takes advantages of instantaneous heating, good penetrate ability etc, a lot of researches have been carried out regarding the application of microwave in AC regeneration both at home and abroad. But all the researches which use microwave to regenerate AC use N₂ as carrier gas. Using the dry air as the carrier gas in the experiments is little, so this research will use the dry air as the carrier gas.In the experiment, the object is the AC which loading the toluene, the regenerating method is microwave radiation, the carrier gas is dry air . The research will survey the wastage and temperature increasing behaviour of AC, the toluene desorption, the changment of absorption capacity of AC which loading the toluene, etc. The research will also survey the microwave's effect on the AC, the effect of microwave regeneration, and evaluate the technology of the microwave regeneration.The experiments on AC wastage and temperature increasing character show that: the temperature increasing velocity of modified activated carbon is higher than AC; the temperature increasing performance of AC was influenced by the microwave power, the oxygen content in the carrier gas, the velocity of carrier gas, ect. On the same condition the wastage of modified activated carbon is higher than AC. So, the the modified activated carbon is not suitable for the research.The experiment on toluene desorption shows that: the alteration of oxygen content will effect on the desorping rate. Under the same condition, the desorping rate of toluene is 78.74% when oxygen's content is 0%, the desorping rate of toluene is 24.3% when oxygen's content is 21%. Based on orthogonal experiment, among the four factors: microwave power, oxygen content, the velocity of carrier gas and the time of radiation, to the effect on the desorping rate, the significance sort is the velocity of carrier gas, the time of radiation, microwave power and oxygen content. The best technology condition for AC regeneration is obtained as follows: the velocity of carrier gas is 800mL/min, oxygen content is 6%, the time of radiation is 3 min , and the microwave power is 231W.The experiment of absorption capacity on AC which loading the toluene shows that: in the process of microwave radiation, the alteration of oxygen content will have effect on the adsorbing ability of regenerated AC to the toluene. After several regenerations the adsorption quantity of AC to the toluene is augmentation. So in the process of regeneration the existent of oxygen has advantage on the adsorbing ability of AC. In the condition of this experiment, the significance sort is the microwave power, the velocity of carrier gas, the oxygen content and the time of radiation. The best technology condition for adsorption of regenerated AC: the microwave power is 231W, the oxygen content is 10%, the velocity of carrier gas is 500mL/min and the time of radiation is 3 min.The result of XRD shows that: the crystal structure of AC has changed after the microwave radiation. The result of N2 adsorption shows that: the specific area of regenerated AC is higher than the fresh AC, so the microwave radiation can enhance the adsorbing ability of AC. After the fractal theory analysis, the result shows that: the microwave radiation has advantage on the adsorption of AC, for the face of regenerated AC is rougher than that of AC.