湿法烟气脱硝技术现状及发展

Current status and trends on wet flue gas denitration technology

NO_x是导致酸雨、形成以及造成温室效应的主要污染物之一,减少NO_x排放是绿色发展的必然要求。本文综述了湿法脱硝技术现状,介绍了碱液吸收法、酸吸收法、络合吸收法、液相吸收还原法、微生物法、氧化吸收法的脱硝原理,详细阐述了NaClO_2、NaClO、H_2O_2、O_3、黄磷乳浊液氧化法、光催化、电环境技术、磷矿浆泥磷一体化脱硫脱硝法的氧化吸收脱硝技术原理和技术特点;分析了脱硝新技术的一些进展,光催化、电环境技术发展迅速,有许多优点,是湿法脱硝技术耦合的重要方向,磷矿浆泥磷一体化脱硫脱硝法通过磷化工与湿法脱硝技术的耦合,充分利用磷化工生产的各个环节,实现原料产品内部循环一体化,在磷化工行业拥有良好的应用前景。指出未来脱硝技术总体要求是低成本、高效、绿色,技术总体发展趋势是多种技术耦合实现多种污染物协同脱除;不同区域、不同行业适用于不同的脱硝技术,应根据资源状况、产品用途合理选择技术方法,降低NO_x排放,降低处理回收成本,提高经济性。

NOx is one of the main pollutants leading to acid rain,smog formation and causing the greenhouse effect. NOx emissions reduction is an inevitable requirement for green development. In this paper,the present situations of wet denitration technology were summarized. The denitration principles of wet denitration technology,including the alkali absorption method,the acid absorption method,the complex absorption method,the liquid phase absorption reduction method,the microbial method,and the oxidation absorption method,were introduced. The oxygen absorption denitration technology principles and technical characteristics of NaClO2,NaClO,H2O2,O3,yellow emulsion oxidation,photocatalytic, electric environmental technology and phosphate slurry with phosphorus mud integrated desulfurization and denitration method were expounded. The development of some new technology of denitrification was analyzed. Photocatalytic and electric environmental technology are developing rapidly and have many advantages,which is an important direction of the coupling of wet denitration. By coupling phosphorus chemical with wet denitration technology and taking full advantage of all aspects of phosphorus chemical production,the integration of internal circulation of raw material and products was achieved. The simultaneous technology route of desulfurization and denitrification in phosphate slurry with phosphorus mud has a good application prospect in phosphoruschemical industry. It was pointed out that in the future the overall requirements of denitration technology would be low-cost,efficient and green. The overall technology trend would be coupling with multiple techniques to achieve the synergistically removal of various pollutants. Different regions and industries adapted to different denitration technologies. Therefore, the resource conditions and product usages should be based on to rationally select technical methods,and to reduce NOx emissions and the processing and recovering costs,as well as to improve the economy efficiency.