| Carbon dioxide, the termination oxidation product of coal, petroleum and carbohydrates, is the largest single source of greenhouse gas, as well as one of the most important resources of C2. From the standpoint of environmental protection and resource utilization, the development of an environmentally benign process utilizing CO2 has drawn current interest in industrial chemistry. Due to its highly thermodynamic stability and kinetic inert, CO2 is usually activated at high temperature, in companion with the deactivation of the catalyst. Therefore, most attentions have been paid for exploring new means or ways to improve the activation of COi-The pulse corona plasma is a novel technology of non-equilibrium plasma generated by highly DC voltage, in which conditions the electron temperature is very high but the ionic or molecular temperature is low. So the great advantages of pulse corona plasma is that less energy goes into activating any stability simple molecular, such as CO2, CFLt, NOX and SOX. In this study, pulse corona plasma or pulse corona plasma combined with catalysts, was used to convert CO2 towards C2 hydrocarbons via two steps, and provides a new rout for activating CO2.The present dissertation deals with: (1) Exploring the feasibility of the CO2 methanation and the conversion CH4/H2 into C2 hydrocarbons under plasma with catalyst at ambient temperature and atmosphere. (2) Designing a reactor and preparing some catalysts suited for the conversion of carbon dioxide via the cooperation effect of plasma and catalysts. (3) Optimizing reaction conditions of conversion carbon dioxide to C2 hydrocarbons in the proposed process. (4) Studying the reaction mechanism of conversion carbon dioxide to C2 hydrocarbons under plasma by using in situ OES technology. (5) By the results of characterizing coked catalysts, exploring the reasons that result in the coking of catalyst and the paths for decreasing the deposit in the catalyst under plasma. (6) Analyzing the energy efficiency of the plasma catalysis and exploring the paths for improving the energy efficiency. The conclusions obtained from this study are summarized as follows: 1. At ambient temperature and atmosphere, carbon dioxide and hydrogen can beeffectively converted into methane under pulse corona plasma with a Ni/y-A^Os catalyst, at the conditions of the ratio of F(H2)/F(C02), the airspeed of feed gases and plasma power is 1:4, 1500h-1 and 26.5W/mlcat, respectively. The conversion of carbon dioxide is 95% and the selectivity of methane is 99%, The results are better than that of by conventional catalytic technique. At the present study, the conversion of carbon dioxide is affected by many factors, such as the ratio of F(H2)/K(CO2), the flow velocity and input manner of feed gas, the configuration of reactor, catalyst and discharge parameters.2. The methane coupling reaction in the hydrogen was realized under pulse corona plasma at ambient temperature and atmosphere. The conversion of CH4 and the yield of C2 hydrocarbons increase with the increase of hydrogen concentration and the coking of catalyst decreases greatly, as well as the distribution of C2 products can be a little extent adjusted. The conversion of methane and the yield of C2 hydrocarbons are largely affected with plasma power, but the distribution of C2 products are not affected. In the activation of CH4/H2 conversion with pulse corona plasma, the presence of catalyst can effectively improve the yield of ethylene, which catalytic activity are in the following order: Pd-La203/SiO2, Pd/SiO2>Cu/SiO2>Pt/Y-Al2O3. Under one of these catalysts with plasma, the yield of C2H4 is all higher than 10%. Among these catalysts, La2O3/SiO2 shows the highest catalytic activity, and yield of C2 hydrocarbons is 30%, while the highest selectivity of 86% for ethylene is obtained with the use of Cu/SiO2 catalyst.3. The analysis results of OES show that the conversion reaction of C02/H2 and CH4/H2 are both radical mechanisms under pulse corona plasma. While the conversion C02 into C2 hydrocarbons und...
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