基于生命周期评价的烧结烟气净化技术比较

烧结烟气是钢铁企业主要污染源之一,活性炭同时脱硫脱硝技术和半干法脱硫+SCR脱硝组合净化技术是目前实现烧结烟气综合净化处理较成熟的方案。运用生命周期评价手段,对国内某钢铁企业2种烟气净化技术进行综合评价。通过收集能源消耗、资源消耗和污染物排放清单,确定能耗分布,并计算得到相应的资源耗竭系数和环境影响负荷。结果表明:能源消耗和资源消耗方面,活性炭法优势明显,能耗和资源耗竭系数仅为半干法脱硫+SCR脱硝组合净化技术的68.38%和59.33%;环境影响方面,二者差距较小,活性炭法环境影响负荷略小。最后,依据生命周期评价结果给出相应建议,综合2种烟气净化技术生命周期评价结果,从能耗、资源消耗和环境影响的角度来看,活性炭法在烧结烟气净化领域具有明显的优势。

Comparison on different sintering flue gas purification technologies based on life cycle assessment

Emission of sintering process is one of the main sources in iron and steel enterprises. Simultaneous desulfurization and denitrification technologies of activated carbon and combination of purification technologies of semi-dry desulfurization and SCR denitrification are two mature solutions to the comprehensive purification of sintering flue gas. The method of life cycle assessment (LCA) was used to synthetically evaluate the two kinds of flue gas purification technologies employed by one steel enterprise. The distribution of energy consumption, resource depletion index and environmental impact load were obtained by collecting energy consumption, resource consumption and pollution emission inventory of the both methods. The results showed that the activated carbon method has more obvious advantages than semi-dry + SCR method, with its energy consumption and resource consuming indicators accounting for 68.38% and 59.33% of the latter. The two methods had little gap in the aspect of environmental impact, and the environmental impact load of the activated carbon method is slightly less than semi-dry + SCR method. Finally, based on the results of LCA, some suggestions were put forward to provide a reference for the flue gas purification engineering of iron and steel enterprises. Comprehensively considering the LCA results of two kinds of technologies, activated carbon method had greater advantages than semi-dry + SCR method in term of energy consumption, material consumption and environmental impact.