烧结烟气氮氧化物减排技术路径探讨

THE DISCUSSION ON TECHNICAL PATHS FOR NO_x EMISSION REDUCTION FROM SINTERING FLUE GAS

阐述了钢铁行业面临的氮氧化物的减排背景以及新颁布实施的钢铁企业污染物减排标准对烧结烟气污染物治理措施的影响,对烧结烟气的特性进行了研究,介绍了活性炭吸附、选择性催化还原(SCR)、催化氧化等烧结脱硝技术路线及其特点,对各种脱硝技术路线的优缺点进行了比较,对烧结脱硝设施建设时需引起关注的问题进行了阐述,揭示了烧结脱硝的独特性。无论采用何种烧结脱硝技术,其建设投资或/和运行成本都很高,直接影响最终产品的竞争力,同时伴随脱硝过程的是能源的消耗和新的污染物的产生。提出通过对生产工况的调整、采取合理的烧结配矿技术以及辅之于一定的末端治理措施,来减少烧结工序氮氧化物的产生与排放,使烧结机头排放烟气中的氮氧化物浓度基本控制在国标规定的排放限值内的设想思路。

The backgrounds of de-NOxthat iron and steel works being faced are reviewed.The characteristics of sintering flue gas and the de-NOxtechnical route,such as activated carbon adsorption,selective catalytic reduction(SCR),catalytic oxidation are introduced.Merits and faults for each technical route are compared.The uniquenesses of de-NOxfor sintering flue gas are stated.The problems needing attention in construction of de-NOxfacilities are expounded.Regardless of any de-NOxtechnology,not only the competitiveness of products would be weakened for the high investment and /or operation cost,but also more energy would be consumed and new pollutants would be generated accompanying with NOxreduction in sintering process.Therefore,a new technical route in which the generation and emission of NOxfrom sintering process would be reduced by adjustment of operating mode and application of suitable ore proportional technology,and the concentration of NOxwould be controlled within the emission limits of national standard have been proposed.