The Mechanism Research On Activated Semi-coke Adsorb Organic Gas And Its Application

Along with the development of industry in our country, different kinds of industrial contamination are increase, too. The source of organic exhaust gas is comprehensive. It is mainly come from spray-paint, presswork, bond, pharmacy, machining plastic and rubber etc. Recently, people gradually realize the tremendous harm of organic exhaust gas to the environment and human health. Therefore, the treatment of organic exhaust gas in environmental domain is more and more recognition.The adsorptive method of activated carbon is one of the widely use technique of treatment VOCs, but it is restricted by cost and regeneration, many academicians are looking after a new adsorbent replace the activated carbon. Semi-coke is the pyrolysis (600～700℃)product of coal, its specific surface area is less than activated carbon, but it is not completely pyrolysis, much hydrogen and oxygen within it. It is abundant of holes and surface configuration, so it is easy for chemic activation. Moreover, it is cheap. The activated semi-coke is certainly to be a new adsorbent which has great marketable attraction.This thesis mainly researches the adsorptive theory of activated semi-coke on the organic gas. Though comparing the adsorptive capability of the raw Datong semi-coke and Shenmu semi-coke, by means of the measurements of physical property and structure, the effect factor of activated semi-coke adsorption is investigated, the appropriate raw material is chose. Though different activated methods and appraise their active capability, seeing about how the heat treatment and surface acid and alkali affect the adsorptive capability of semi-coke. By the means of orthogonal experiment, comparing different adsorptive condition, the factors which affect the activated semi-coke are researched. It can provide reference for industrial application.The investigative result indicate that: Compared with the raw Shenmu semi-coke, the raw Datong semi-coke has more specific surface area and pore volume, less ash, oxygen content is more than 10%.This characteristic is propitious to be activated and it has better adsorptive capability. Therefore, the raw Datong semi-coke is adaptive to manufacture activated semi-coke. Activated by nitric acid, its functions are: one is wipe off ash; the other is made the oxidation reaction take place in the surface of semi-coke, the oxidative group has great effect on chemic adsorption. The third is activated by nitric acid can improve the specific surface area and pore volume. Heat treatment can make the specific surface area of semi-coke increased. Activated by HNO₃ and heat treatment, the surface acid and alkali group of the semi-coke is changed, which is good for the activated semi-coke to adsorb organic gas. The optimum conditions for preparation of activated semi-coke are: the raw DaTong semi-coke immersed in 45% nitric acid , temperature 80℃for 4 hours and then washed with water until PH6 and drying. Than the semi-coke is heated in the flow of N2, at the temperature of 400℃. The orthogonal experiment indicates that: the order of factor effect the adsorptive capability is inlet concentration>gas velocity>the bed height. Low gas velocity high inlet concentration is good for the toluene adsorption of activated semi-coke. The adsorptive effect is good when the inlet gas is at the temperature of 40℃.