Basic Research On Preparation Of Activated Carbon From Solid Organic Waste

Resource and environment are two topics in 21^st century,and disposal of municipal refuse is an important task in the two topics.With the rapid development of the economy and enlargement of city scale in China,the city population and municipal refuse are increasing rapidly.Refuse will become an effective energy resource with right disposition and the energy consumption stress will be relieved.It has great practical significance in city environment protection,development of national economic and adjustment of energy structure.Pyrolysis technology is one of important refuse disposal techniques in preparation of activated carbon from solid organic wastes with little secondary pollution,quite innocuity and high reusability,and it has been paid more attention from all over the world.Activated carbon has been used widely as an adsorption material in chemical industry, environment protection,food industry,pharmaceutics,catalyst carriers and electrode materials,etc.With the development of science and technology,the demand for activated carbon is increasing rapidly.In this paper,the activated carbon was prepared by chemical activation with NaOH under nitrogen atmosphere from polycarbonate(PC) particles in the size range of 0.59-0.85 mm,while the activation temperature is set at 773K.The activation time and NaOH/PC ratio were planned according to Central composite design.The BET surface area and D-R micropore volume of activated carbon were determined through ASAP 2000 with nitrogen at 77K.The characteristics of activated carbon prepared at different activation time and chemical ratio were studied.As a result,the N₂ adsorption isotherms are typical of Typeâ… while the water vapor isotherms are of Typeâ…£,representing micropores are developed with the increase of activation time and chemical ratio,although the micropores were enlarged to mesopores or macropores.Response surface methodology was used to establish the optimum levels of independent processing factors(activation time at 773 K and NaOH/PC ratio) for obtaining maxima of BET surface area and D-R micropore volume with the second degree polynomial model,853.3 m²/g and 0.3678 mL/g,respectively.The second degree polynomial model of water vapor amount absorbed was also determined for obtaining maxima of Q_(0.35-0.10) and Q_0.95, 0.2373 kg/kg and 0.5577 kg/kg,respectively.The contour plots are used to inspect the effect of activation time and chemical ratio on characteristics of activated carbon,which is nonlinear.