基于烧结烟气波动特性大数据分析的多污染物协同净化技术及机理研究

In response to increasingly stringent emissions legislation, developing a technology to collaborative purification of the multi-pollutants has become the general trend. The application of active carbon (coke) to absorb SO2, NOx and Hg simultaneously has a good prospect of application in industry. However, the effect and cost of the purification of the multi-pollutants in sintering flue gas does not achieve the desired effect because of the actual problem such as the fluctuation of sintering flue gas. In this project, big data analysis methods will be introduced to study the fluctuation of sintering flue gas properties. Based on the active carbon method, a route of removing multi-pollutants step by step by using the advanced activated coke was proposed in this project. The mechanism of removal of various pollutants (SO2, NOx, and Hg) is investigated systematically and the interaction effect of these pollutants would be clarified. Guided by these results obtained above, catalytic materials with high sulfur capacity and high stability, catalysts with strong oxidizing characteristics to oxidize Hg and CO simultaneously, high-efficient catalyst for low-temperature SCR reaction were developed respectively by using active coke as the support and introducing various active components. Finally, the target of multi-pollutants (SO2, NOx, Hg and dioxin) removed in a single tower step by step will be achieved which will provide the guidance for the industry application.

随着环保法规的日益严格，钢铁烧结烟气多污染物的协同净化成为大势所趋。干法工艺中的活性炭（焦）吸附法可以实现SO2、NOx、汞等污染物的有效协同控制，具有良好的推广应用前景。但因烧结烟气波动性大等实际问题，使得烟气综合净化效果并不理想，且成本颇高。本课题拟采用大数据分析方法对烧结烟气特性的波动规律进行研究，在活性焦法基础上，提出一条适应烟气波动特性的层进式的短流程污染物协同净化技术路线。对SO2、NOx、Hg等污染物的脱除机理进行系统研究，明确各污染物彼此之间的相互影响和其他物质对其脱除的作用规律。在此理论指导下，基于活性焦等基材，研发出高硫容的脱硫材料、双功能强氧化催化剂（Hg、CO）以及高效低温SCR催化剂，实现烧结烟气硫硝汞等多污染协同净化的目标，为未来工业应用提供理论指导。

目前在烧结烟气末端治理环节，由于矿品、燃料的差异，引起烟气量、污染物排放浓度与现有或新建污染物治理设施设计范围不匹配，导致烟气末端治理设施需改扩建，甚至推倒重来。针对上述问题，本课题建立并分析了烧结烟气特性大数据库，提出了更为合理的层进式脱硫-脱硝-脱汞一塔脱除的技术路线，探究了烧结烟气各组分关联耦合作用机制，开发出高活性和稳定性吸附剂/催化剂，优化了工艺参数并研究了各层的耦合情况，实现了SO2-Hg-NOx的一塔式固定床干法净化的目标。.首先，分类收集海量的离散的烟气实际数据，并采用大数据处理方法对此进行分析研究，确定烟气各组分含量以及温度随操作条件、工况等因素的内在关联规律，为整个体系工艺参数的确定提供理论依据和技术支持。其次，开发了高硫容、高稳定活性焦催化脱硫材料（80min内保持100%的脱硫效率，40min内保持40%以上的脱硝效率）、双功能强氧化催化净化剂（当反应温度为200oC，含氧量为16%时，活性焦催化剂脱Hg0效率大于70%，脱CO效率约为100%）、以及低温脱硝催化剂（在150~200 ℃的温度区间内脱硝活性稳定在90%以上）。在以上研究的基础上，对不同浓度和温度的烧结烟气进行处理，考察以上吸附/催化材料活性和稳定性变化。除此之外，建立了固定床反应塔内气固流动与脱硫脱硝脱汞反应耦合的三维数理模型，确定了模拟对象与条件。最后，通过Fluent数值模拟软件，考察了烟气流速、催化剂空速、烟气温度、SO2、NOx和Hg的初始浓度对各层污染物脱除效果的影响。本项研究为环境治理及多污染物协同脱除提供了一定的依据，为活性焦吸附/催化材料的设计与制备提供了新的思路，对大气污染控制具有十分重要的意义。