微波辐照活性炭同时脱硫脱硝的应用基础研究

发布时间：2018-10-12 21:08

【摘要】：我国电厂主要以燃煤为主,煤的燃烧会产生SO2、NOX、CO、VOC(挥发性有机化合物)、炭颗粒和尘灰等这些空气污染物和固体废物。其中SO2是酸雨和硫酸烟雾的前体物,NOx则在大气中引起光化学烟雾,若SO2和NOx得不到有效地控制,其对环境将会带来巨大的危害,不利于我国经济的健康发展。目前我国燃煤电厂脱硫脱硝技术存在投资大、运行维修费用昂贵等缺点,因此研究一种低成本、高效无二次污染的烟气污染物控制技术成为了一项重要的课题。微波辐照活性炭同时脱硫脱硝技术将SO2和NOx还原成为对环境无害的单质硫及氮气,是一种高效的脱硫脱硝一体化技术。本论文通过实验研究了微波辐照过程中氧气对活性炭理化特性的影响及微波辐照活性炭脱硫脱硝过程中副产物CO生成机理。结果显示,烟气中氧气加速了活性炭的质量损失,在氧含量为2-4.5%活性炭损耗率增加最快;氧气与活性炭发生烧损,破坏了孔结构,活性炭的比表面积减小,活性炭表面碱性基团含量降低,酸性基团含量则有所增加,烟气中氧气促进了活性炭对SO2和NO的还原效率,SO2还原效率由95.3%增高至100%,NO还原效率则由81.5%增高至96.8%;活性炭吸附SO2、NO实验表明随微波再生次数、烟气流速的增加,活性炭对SO2和NO吸附性能逐渐降低,烟气中O2、水蒸汽、则对活性炭吸附SO2和NO有促进作用;微波辐照解吸还原实验表面,CO生成量随着微波功率、辐照时间、吸附容量、氧含量、CO2含量的升高而升高,而烟气中水蒸汽则抑制了CO的生成;微波辐照活性炭还原SO2和NO动力学计算得到活性炭还原SO2生成CO的活化能为28.31kJ/mol,还原NO生成CO的活化能则为16.24kJ/mol。此外,本论文还针对微波非连续辐照活性炭同时脱硫脱硝的工业化应用进行了计算,对其理论可行性、经济可行性和环境效益进行了分析。
[Abstract]:Coal combustion will produce SO2,NOX,CO,VOC (volatile organic compounds), carbon particles, dust and other air pollutants and solid waste in power plants in China. SO2 is the precursor of acid rain and sulfuric acid smoke, and NOx causes photochemical smog in the atmosphere. If SO2 and NOx are not effectively controlled, it will bring great harm to the environment and is not conducive to the healthy development of our economy. At present, the technology of desulfurization and denitrification in coal-fired power plants in our country has many disadvantages, such as large investment, high cost of operation and maintenance, and so on. Therefore, it has become an important subject to study a kind of low cost, high efficiency and no secondary pollution control technology of flue gas pollutants. The technology of simultaneous desulfurization and denitrification of activated carbon irradiated by microwave has reduced SO2 and NOx to simple sulfur and nitrogen which is not harmful to the environment. It is a highly efficient technology of desulfurization and denitrification. In this paper, the effects of oxygen on the physical and chemical properties of activated carbon during microwave irradiation and the formation mechanism of by-product CO in the process of desulfurization and denitrification of activated carbon under microwave irradiation were studied experimentally. The results showed that oxygen accelerated the mass loss of activated carbon, and the loss rate of activated carbon increased fastest when oxygen content was 2-4.5%, oxygen and activated carbon were burned out, the pore structure was destroyed, and the specific surface area of activated carbon decreased. The content of basic group on activated carbon surface decreased, while the content of acidic group increased. Oxygen in flue gas promoted the reduction efficiency of SO2 and NO by activated carbon, and the reduction efficiency of SO2 increased from 95.3% to 100%. The reduction efficiency of no increased from 81.5% to 96.8.The adsorption of SO2,NO on activated carbon showed that the flow rate of flue gas increased with the number of times of microwave regeneration. The adsorbability of activated carbon to SO2 and NO decreases gradually, and O _ 2 and water vapor in flue gas can promote the adsorption of SO2 and NO by activated carbon. The amount of CO produced by microwave irradiation desorption and reduction experiment surface is dependent on microwave power, irradiation time and adsorption capacity. With the increase of oxygen content and CO2 content, the formation of CO was inhibited by water vapor in flue gas, the activation energy of active carbon reducing SO2 to CO was 28.31kJ / mol, and that of reducing NO to CO was 16.24kJ / mol. In addition, the industrial application of simultaneous desulphurization and denitrification by microwave discontinuous irradiation activated carbon was calculated, and its theoretical feasibility, economic feasibility and environmental benefit were analyzed.
【学位授予单位】：华北电力大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X773

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