炭基燃料燃烧利用过程中NO_X释放控制技术进展

Technical progress of the control of NO_X emission in carbon based fuel combustion process

炭基燃料燃烧产生的氮氧化物严重污染了大气环境,依据其产生途径主要分为三大类:热力型NO_X、快速型NO_X和燃料型NO_X,其中占比最多的是燃料型NO_X,研究燃料型NO_X的脱除对开发有效的NO_X控制技术具有重要意义。分别从燃烧前、燃烧中、燃烧后三大方面对燃料型NO_X的脱除作了详细的综述,即燃烧前原料脱硝:加氢脱硝、洗选、中温干馏和高温热解等;燃烧中脱硝:低NO_X燃烧、烟气再循环、解耦燃烧、催化还原等;燃烧后烟气脱硝:选择性非催化还原脱硝、选择性催化还原脱硝、活性炭吸附、电子束脱硝等。基于民用散煤燃烧利用现状,低NO_X燃烧技术和烟气脱硝技术的推广使用逐渐出现了诸多限制因素,提出在炭基燃料原料中添加金属化合物助剂,借助于中、高温干馏的燃烧前原料脱硝和燃烧中选择性催化还原NO_X两步,达到不需要设置烟气脱硝装置就可实现炭基燃料燃料型NO_X释放控制的新技术。

The nitrogen oxides produced by the combustion of carbon-based fuel seriously pollute the atmospheric environment,and according to its generation approaches NO X is divided into three main categories:thermodynamic NO X,fast NO X and fuel-type NO X.Among them,fuel NO X is the most big one,so it is important to study the removal of fuel-type NO X for the development of effective NO X control technology.The removal of fuel-type NO X is reviewed in detail from three aspects:before,during and after combustion.That is,pre-combustion raw material denitrification:hydrodenitration,washing,mid-temperature distillation and high-temperature pyrolysis;Denitrification in combustion:low NO X combustion,flue gas recirculation,decoupling combustion,catalytic reduction,etc.Post-combustion flue gas denitrification:selective non-catalytic reduction denitrification,selective catalytic reduction denitrification,activated carbon adsorption,electron beam denitrification and so on.Based on the present situation of civil bulk coal combustion,the application of low NO X combustion technology and flue gas denitrification technology has gradually appeared many limiting factors.In view of the existing problems,this paper proposes thea new technology of adding metal compound auxiliaries to the carbon-based fuel,with the help of two steps of pre-combustion raw material denitrification such as mid-temperature or high-temperature pyrolysis and denitrification in combustion such as catalytic reduction NO X,to achieve the control of fuel-NO X emission in carbon based fuel not required flue gas denitrification equipment.