| Elutrilithe is currently one kind of solid waste with largest quantities and accumulation in China. It not only takes the land source massively but also easily self-ignites, and all these can cause water and air pollution extremely. In this case, exploiting elutrilithe efficiently to provide the high value-added products is very significant.China is gravely facing the increased international pressure and environment impact to cut greenhouse gas (CO2) emission, while CO2 utilization is widespread. It is very necessary and imminent to do research for the emission and utilization of CO2.In addition, development and integrative utilization of coal-bed gas is becoming a hot research trend, collectively driven by relieving energy shortages, decreasing coal mine accidents, reducing green house gas emission and minimizing environmental pollution. Therefore, it is urgent to solve the problem of concentrate and purification of CH4 in coal-bed gas to integrative utilization of CH4. Herein, two research aspects were included. The first one, on the basis of the former research of our Labrador, LSX/AC was synthesized to enhance the application of zeolite/AC composite materials; the second one, studying the adsorption properties of CO2, CH4 and N2 on the zeolite X/AC composite materials to provide a high-efficiency adsorbent for PSA or methane concentration technology and to provide the basis data for the practical application of this composite material. The special research content and the results include the follows:1. LSX/AC composite material, mainly containing LSX zeolite phase and a few zeolite A, was prepared via 6 steps (blend-extrusion- dry-carbonization-CO2 activation-Hydrothermal crystallization) from elutrilithe as raw material combined with some pitch and SiO2. This composite material has large total surface as high as 456m/g, in which the mesoporous surface area is 126m/g, indicating the complex of zeolite and active carbon. The best conditions for the synthesis of this material have been achieved:H2O/(Na2O+K2O)=17, (Na2O+K2O)/SiO2=3.5, K2O/(Na2O+K2O)=0.3, gel temperature:65℃, gel time:24h, ageing time:12h and crystallization time:65℃.2. Two kinds of zeolite X/AC, separately prepared by direct thermal synthesis and modification by NH4Cl solution, were used as adsorbents. Adsorption of CO2,CH4 and N2 were investigated and the fitting parameter were compared. The effect of ratio of zeolite and activated carbon and the change of surface properties owing to the modification by NH4Cl solution on the adsorption behavior of each gas was investigated.The results of XRD and low temperature N2-adsorption of zeolite X/AC composite materials treated by NH4Cl solution show that the materials still maintain the crystal structure, whereas the mesoporous surface area is remarkable increased, and the ratio of mesoporous surface area to total specific surface area is also increased to some extent.The data obtained from CO2,CH4 and N2 isothermal adsorption on two samples were simulated with Fraudlich, Langmuir-Fraudlich and Toth adsorption models. Based on the analysis of fitting parameters and adsorption heat calculated, the conclusions can be drawn as follows:on the same adsorption conditions, the adsorption abilities of two samples are followed by CO2>CH4>N2 and the adsorption amount decrease with the carbon contents increasing, reflecting the adsorption abilities of the zeolite for each gas are greater than that of carbon activated; Yet, along with the carbon contents increasing, the adsorption heat of gas on samples surface decrease, the diversities of adsorption surface reduce and the mutual action between adsorbents and adsorbates decline. After treated by NH4Cl solution, the saturated adsorption capacity on these samples of each gas is decreased, the diversities of adsorption surface reduced, the adsorption strength weaken and the adsorption heat drop for the gas, especially for acid molecules CO2 owing to the NH4Cl solution treatment make the surface alkalinity of sample weaken.As increase of pitch adding amount, CO2/CH4, CO2/N2, CH4/N2 decrease in the composite materials at 298 K,99.3 KPa. but compared with sample before modification, the separation ratio of modified sample increase distinctly。...
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