| The pollution of atmosphere is becoming seriously, NOx can form photochemistry and acid rain. NO as one of the main air pollutants can cause acid rain and photochemistry fog, endanger the humanity as well as ecological environment. At present, selective catalytic reduction (SCR) is the main exhaust gas denitration method. However, the Problems of SCR appear to be the narrow temperature operation band, catalyst poisoning, ammonia leakage and the high cost. Presently many emerging technologies are focusing on systems capable of controlling NOx emissions and overcoming the problems of SCR, for their particular advantages in the cleaning of air pollution, such as high removal efficiency and low energy consumption, non-thermal plasma technologies have gradually attracted more and more attentions. Choosing Suitable additives, catalysts, adsorbents, or fillers combined with low-temperature plasma is relatively promising technology. The non-thermal plasma (NTP) assisted catalytic decomposition technology could avoidance of high temperatures required in the case and improves the decomposition efficiency. This paper systematically investigated the NO removal in coal-fired flue gas by the Catalyst adsorption with the non-thermal plasma technology. The research results in this paper were summarized as follows.(1) The NTP alone, NTP assisted catalytic decomposition and adsorption-NTP catalytic decomposition are each studied for the NO removal for comparative purposes. The energy efficiency and NO removal efficiency of these processes were investigated. The adsorption-NTP catalytic decomposition method feasibility was studied.(2) Comparison the reactivity of three adsorbent, choose coconut shell activated carbon as a carrier which have a high specific surface area and pore volume. An excessive dipping method was used to prepare catalyst composed of difference carrier and transition metal nitrates as the active component. We investigated the effect of preparation conditions on reactive activity. The optimal preparation conditions were as follows:coconut shell activated carbon as a carrier, copper nitrate as the precursor, Cu loading10%, calcination temperature for catalyst400℃. The catalysts characterized by Dynamic adsorption, FT-IR, TPD, XPS to obtain its structure and morphology, then, discussed the effects of the preparation method on reactive reactivity. The results showed that: The catalyst used of copper nitrate as the precursor with large adsorption capacity and copper ions on the decomposition of NO, make its have high energy efficiency. Moreover, Catalyst which loading of10%Copper has good performance is that the surface of catalyst contain more Cu2+.(3) In order to optimize the NTP reactor parameters, the influencing factors (e.g. discharge voltage, Power frequency, running time, repetitions) on adsorption-NTP catalytic decomposition were investigated. Results show that: Under the same conditions, with the discharge voltage increases, NO removal rate increases, energy efficiency is reduced. The voltage is constant, increases with the frequency of the power supply, energy reduction, removal rates first increase and then decrease. Little change in conversion rate with running time, as the NTP uptime increases, energy efficiency reduces. Integrated energy efficiency and removal rate, matching catalysts in the breakdown voltage is4.5kV, power supply frequency is7.5kHz, run time was15min, the reaction is best. The catalysts characterized by BET, and XPS. The results indicated that: as the number of repetitions increases, the total pore volume and pore volume of catalysts has declined, increase in the proportion of micro-porous, repeated eight times after the generated most of copper oxide on the surface of catalysts, result in reduced adsorption capacity and reducing levels of Cu2+on the surface of it, makes it down to reduce, and eventually led to lower its overall activity.(4) Influences of the inlet concentration on NO oxidation have been studied in. It was found that: in a certain range, the NO removal efficiency was over94%. Under optimum conditions of the experiment, the initial concentration of500ppm is the best. Oxygen is the active species in the catalyst surface. The effect of the oxygen concentration (0%,3%,5%,8%) was investigated. NO removal efficiency increases with the oxygen content. When the oxygen concentration was too high occurred side reactions, that is, inhibit the conversion of NO and increase the concentration of NO. When the oxygen concentration was too high occurred side reactions, that is, inhibit the conversion of NO and increase the concentration of NO. In addition, this test system has the best space velocity, space velocity smaller, residence time increased, the NO removal rate is higher, with the increase of space velocity, the residence time decreases, the NO removal rate decreases. |
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