钢铁行业烧结烟气脱硫脱硝技术研究进展

钢铁行业是我国重要的基础行业,也是典型的高污染行业,每年排放大量的二氧化硫(SO₂)和氮氧化物(NO_x)等大气污染物。随着钢铁行业超低排放标准的实施,对大气污染有主要贡献的烧结工序亟须改造现有的或新建先进的脱硫脱硝设施。在介绍烧结烟气特点和排放标准变化的基础上,综述了目前主流应用的单独脱硫技术、单独脱硝技术和同时脱硫脱硝技术的应用现状,以及实验研发阶段的同时脱硫脱硝技术的研发进展,并系统展望了各类技术的未来发展前景。指出在单独脱硫和脱硝技术中,半干法和低温选择性催化还原法(SCR)更具应用潜力,且半干法脱硫+袋式除尘+SCR的工艺组合环境效益最高;同时脱硫脱硝技术中,氧化法和活性焦法尚需进一步提高效率和降低成本,同时脱硫脱硝技术具有潜在发展前景。

RESEARCH PROGRESS OF DESULFURIZATION AND DENITRATION TECHNOLOGIES FOR SINTERING FLUE GAS IN IRON AND STEEL INDUSTRY

The iron and steel industry is a key basic industry in China, and a typical industry with high air pollutant emissions, including huge quantities of sulfur dioxide(SO₂) and nitrogen oxides(NO_x). With the implementation of ultra-low emission standards in the iron and steel industry, it is urgent to renovate the existing or build new advanced desulfurization and denitration facilities in the sintering process. Based on the introduction of the characteristics of the sintering flue gas and the changes in emission standards, this paper summarizes the application status of separate desulfurization technologies, separate denitrification technologies and simultaneous desulfurization and denitration technologies, as well as the research and development progress of simultaneous desulfurization and denitration technologies, and systematically looks forward to the future development prospects of these technologies. The results indicate that among the separate desulfurization and denitrification technologies, semi-dry desulfurization and low temperature selective catalytic reduction(SCR) denitration have a high potential for application. Meanwhile, the process combination of semi-dry desulfurization+bag dust-removal+SCR has the highest cleaning efficiency. Among the simultaneous desulfurization and denitrification technologies, oxidation method and activated coke method still need further improvement in efficiency and cost, and the simultaneous desulfurization and denitrification technologies in research have a promising potential for long-term development.