基于煤的解耦耦合燃烧原理和烟气返回脱硝技术,并结合烧结工序特点,提出了烧结过程中解耦燃烧与烟气返回共脱硝新工艺,详细介绍了该工艺的基本原理和工艺流程,对其可行性进行了热力学计算分析;重点研究了烧结矿带发生的脱硝反应.利用烧结矿作填料,采用H2、CO和NH3模拟热解气主要组分对返回烟气中NOx的脱除进行了实验研究.结果表明,450-550℃下烧结过程引入4.0%的H2或4.0%的CO,可使NOx的浓度降低20%-40%;620-660℃时烧结过程引入0.15%的NH3,可使NOx浓度降低20%-30%.烧结过程解耦燃烧与烟气返回共脱硝工艺可有效减少NOx的排放,同时可降低烧结能耗.
Decoupling combustion of coal and denitrification via flue gas recycling are combined with the iron ore sintering process in a new technique of denitrification during sintering.The principles and technology of this new technique are introduced in detail in this paper.The feasibility of this new technology was analyzed by thermodynamic calculations,particularly testified by the denitrification reaction in the sintered ore layer experimentally.The reduction of NOx in recycled flue gas by the major components of pyrolysis gas(simulated by H2,CO and NH3)over sintered ore was investigated.The results show that the concentration of NOx in the flue gas is reduced by 20%-40% from 450℃ to 550℃ with 4.0% H2 or 4.0% CO,and the concentration of NOx in flue gas is reduced by 20%-30% from 620℃ to 660℃ with 0.15% NH3.The new denitrification technique with decoupling combustion and flue gas recycling can effectively decrease NOx emissions in the sintering process,and the energy consumption of the iron ore sintering process is simultaneously reduced.