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.