Mg-AI复合氧化物用于同时脱硫脱硝的实验及机理研究
发布时间：2019-06-10 19:14
【摘要】：在中国,大气中的二氧化硫和氮氧化物主要来自于燃煤电厂,控制燃煤电厂气体污染物排放是整个电力工业乃至国民经济可持续发展的必要条件。单独采用脱硫工艺和脱硝工艺占地面积大,投资成本高,研究和开发一种同时脱硫脱硝的工艺是节省资源的一个热点。Mg-Al氧化物由于其来源丰富,成本较低,作为吸附剂已经得到很多的应用,在同时脱硫脱硝方面有很大的潜力。减小粒径是提高Mg-Al氧化物脱硫脱硝效率的一个突破点。本文通过固相法和熔盐法分别制备不同Mg/Al摩尔比的Mg-Al复合氧化物,并在湿法反应器上进行同时脱硫脱硝的实验。发现当样品中Mg的量比A1的量多时,S02和NOx的脱除效果明显比A1元素多的样品的脱除效果好很多。采用熔盐法制备的样品的脱除效率明显比固相法制备的样品的脱除效率高。采用固相法合成时,制备温度对S02的脱除率的影响比对NOx脱除率的影响更大。采用较低制备温度有利于脱除S02。其中,Mg/Al摩尔比为6：1时的样品的脱除效果为最好,SO2脱除率最高能达到99%,NOx脱除率最高能达到45%,并且经过60mmin后脱硫率仅下降3.4%,脱氮率仅下降1.5%。采用熔盐法合成时Mg/Al摩尔比为4：1的样品的脱除效果为最好,S02脱除率最高能达到100%,NOx脱除率最高能达到71%,脱硫率和脱硝率在高效区间能维持150min,其脱除率所处的系统高效区间是固相法的2.5倍之多。利用吸附动力学方程对整个吸附过程进行拟合。结果表明整个吸附过程主要受吸附质分子与吸附剂分子的反应过程控制,而吸附质分子扩散到吸附剂分子的表面以及在吸附剂内部的扩散过程不是整个过程速率的决定性因素。
[Abstract]:In China, sulfur dioxide and nitrogen oxides in the atmosphere mainly come from coal-fired power plants. Controlling the emission of gas pollutants from coal-fired power plants is a necessary condition for the sustainable development of the whole power industry and even the national economy. Using desulphurization process and denitrification process alone occupies a large area and has high investment cost. It is a hot spot to research and develop a simultaneous desulphurization and denitrification process. Mg-Al oxide has rich sources and low cost. As an absorbent, it has been widely used and has great potential in simultaneous desulfurization and denitrification. Reducing particle size is a breakthrough point to improve the desulphurization and denitrification efficiency of Mg-Al oxide. In this paper, Mg-Al composite oxides with different Mg/Al molar ratios were prepared by solid phase method and molten salt method, and the simultaneous desulfurization and denitrification experiments were carried out in a wet reactor. It is found that when the amount of Mg in the sample is more than that of A1, the removal effect of S02 and NOx is much better than that of the sample with more A1 elements. The removal efficiency of the samples prepared by molten salt method is obviously higher than that of the samples prepared by solid phase method. When synthesized by solid phase method, the effect of preparation temperature on the removal rate of S02 is greater than that of NOx. The lower preparation temperature is beneficial to the removal of S02. Among them, when the molar ratio of Mg/Al is 6: 1, the removal rate of SO2 is the best, the highest removal rate of NOx is 99%, the highest removal rate of SO2 is 45%, and the desulphurization rate decreases only 3.4% after 60mmin. The denitrification rate decreased by only 1.5%. When the molar ratio of Mg/Al is 4:1, the removal effect of S02 is the best, the highest removal rate of S02 is 100%, the highest removal rate of S02 is 71%, and the desulphurization rate and denitrification rate can be maintained in the high efficiency range. The removal rate of the system is 2.5 times higher than that of the solid phase method. The adsorption kinetics equation was used to fit the whole adsorption process. The results show that the whole adsorption process is mainly controlled by the reaction process between the adsorbents and the adsorbents, but the diffusion of the adsorbents to the surface of the adsorbents and the diffusion process within the adsorbents is not the decisive factor of the rate of the whole process.
【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
本文编号：2496673
[Abstract]:In China, sulfur dioxide and nitrogen oxides in the atmosphere mainly come from coal-fired power plants. Controlling the emission of gas pollutants from coal-fired power plants is a necessary condition for the sustainable development of the whole power industry and even the national economy. Using desulphurization process and denitrification process alone occupies a large area and has high investment cost. It is a hot spot to research and develop a simultaneous desulphurization and denitrification process. Mg-Al oxide has rich sources and low cost. As an absorbent, it has been widely used and has great potential in simultaneous desulfurization and denitrification. Reducing particle size is a breakthrough point to improve the desulphurization and denitrification efficiency of Mg-Al oxide. In this paper, Mg-Al composite oxides with different Mg/Al molar ratios were prepared by solid phase method and molten salt method, and the simultaneous desulfurization and denitrification experiments were carried out in a wet reactor. It is found that when the amount of Mg in the sample is more than that of A1, the removal effect of S02 and NOx is much better than that of the sample with more A1 elements. The removal efficiency of the samples prepared by molten salt method is obviously higher than that of the samples prepared by solid phase method. When synthesized by solid phase method, the effect of preparation temperature on the removal rate of S02 is greater than that of NOx. The lower preparation temperature is beneficial to the removal of S02. Among them, when the molar ratio of Mg/Al is 6: 1, the removal rate of SO2 is the best, the highest removal rate of NOx is 99%, the highest removal rate of SO2 is 45%, and the desulphurization rate decreases only 3.4% after 60mmin. The denitrification rate decreased by only 1.5%. When the molar ratio of Mg/Al is 4:1, the removal effect of S02 is the best, the highest removal rate of S02 is 100%, the highest removal rate of S02 is 71%, and the desulphurization rate and denitrification rate can be maintained in the high efficiency range. The removal rate of the system is 2.5 times higher than that of the solid phase method. The adsorption kinetics equation was used to fit the whole adsorption process. The results show that the whole adsorption process is mainly controlled by the reaction process between the adsorbents and the adsorbents, but the diffusion of the adsorbents to the surface of the adsorbents and the diffusion process within the adsorbents is not the decisive factor of the rate of the whole process.
【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
【参考文献】
相关期刊论文 前2条
1 钟毅,曾汉才,金峰,张鹏宇;联合脱硫脱硝技术的现状[J];电力科学与工程;2002年04期
2 乔梅英;陈可可;;均匀沉淀法制备纳米氧化镁[J];郑州大学学报(工学版);2013年04期
，本文编号：2496673
本文链接：https://www.wllwen.com/kejilunwen/huanjinggongchenglunwen/2496673.html
