燃煤水泥窑炉低排放控制技术研究进展 -

我国是水泥生产和消费大国,水泥行业已成为我国继热力发电和交通运输之后的第三大NO_x排放源,是引起我国雾霾天气的主要成因之一。随着水泥工业NO_x排放标准的不断提高,燃煤水泥窑炉低NO_x排放控制技术的发展越来越受到重视。为清晰了解水泥行业常见低NO_x排放控制技术的优化方向和新型低NO_x排放控制技术的发展现状,为水泥工业实现超洁净绿色生产提供技术储备,笔者梳理总结了燃煤水泥窑炉常见低NO_x排放控制技术以及新型低NO_x排放控制技术。围绕燃煤水泥窑炉常见低氮脱硝技术,阐述了燃烧前、燃烧中以及燃烧后等各种低NO_x排放控制技术的降氮原理、特点以及应用现状,并指出了这些技术在实际应用中面临的问题;同时介绍了燃烧前、中、后等各种低NO_x排放控制技术的组合应用。重点介绍了近年来新涌现出的以两步还原法为代表且具有潜力的低氮脱硝技术,论述其降氮原理及研究发展现状,对比总结了水泥行业常见低NO_x排放控制技术以及新型低NO_x排放控制技术的脱硝效率、研究和应用现状。面对日益严峻的减排形式,水泥行业深度脱硝工作的开展势在必行。结合常见低NO_x排放控制技术的减排原理、优势以及存在的问题,建议水泥行业可采用燃烧中与燃烧后各种低氮控制技术的组合应用方案,以此达到降本增效的目的,并具体提出了水泥行业现有生产线以及新建生产线可行的组合应用方案。考虑到各种新型低NO_x排放控制技术的降氮原理和发展现状,笔者对水泥行业低氮脱硝技术未来的研究和努力方向进行展望,认为未来水泥行业低NO_x排放控制技术的发展应注重提高还原氛围下的碳还原能力,以激发碳还原能力为核心进行现有技术的优化以及新技术的探索,同时应考虑到与低氮燃烧技术相匹配的精准自动化、智能化测控设备的应用,以全方位监测、反馈系统的相关指标,更好地发挥低NO_x排放控制技术的降氮脱硝效果。 China is the largest cement producer and consumer in the world,and NO_x emission from cement industry has become the third largest emission source since thermal power generation and transportation,which is one of the main reasons causing the haze weather in China. With the improvement of NO_x emission standards in the cement industry,more and more attention has been focused on the low NO_x emission control technologies for coal-fired cement kilns. In order to clearly understand the optimization direction of the common low NO_x emission control technology and the development status of the new low NO_x emission control technologies in the cement industry,and provide references for cement enterprises to achieve ultra clean and green production,the conventional and emerging low nitrogen denitration technologies used in coal-fired cement kilns were summarized and analyzed in this paper. Firstly,in the view of the conventional low nitrogen denitrification technologies in coal-fired cement kilns,the principles,characteristics and application status of these technologies were stated according to the classification of before,during and after the burning of the fuel,and the problems encountered in practical application were further pointed out. And the combined application of various low NO_x emission control technologies before,during and after combustion were also introduced briefly. Secondly,in the view of the emerging low nitrogen denitrification technologies with two-step NO_x reduction method as representative,in this paper,the nitrogen reduction principles and research status of these methods were focused on. And the denitrification efficiencies,research and application status of various low NO_x emission control technologies in cement industry were compared and summarized. Facing the increasing