汽车钢板生产的生命周期评价

Life cycle assessment of automotive steel sheet production

在“碳达峰、碳中和”的驱动下,汽车制造业是节能减碳的重要组成部分,作为资源能源密集型产业,它采用汽车钢板作为主要材料,具有生产能耗和排放高的典型特点。采用生命周期评价(life cycle assessment,LCA)方法,分别对汽车钢板生产长流程工艺(BF-BOF)和短流程工艺(EAF)2种生产工艺的各阶段进行环境影响评价和贡献分析。结果表明,在汽车钢板生产长流程工艺(BF-BOF)中,炼铁工序和烧结工序对总环境影响的贡献较大;在汽车钢板生产短流程工艺(EAF)中,炼铁工序和电炉炼钢工序对总环境影响贡献较大。汽车钢板生产EAF工艺的各类环境影响均低于BF-BOF工艺,环境影响优势较大的有全球变暖(GWP)、化石能源耗竭(FFP)、矿产资源耗竭(SOP)、淡水富营养化(FEP)、海洋富营养化(MEP)、淡水生态毒性(FETP)、人体致癌毒性(HTPc)、人体非致癌毒性(HTPnc)。BF-BOF工艺和EAF工艺的矿产资源消耗铜当量分别为85.6 kg/t和25.6 kg/t,综合能耗分别为541 kg和265 kg,CO_(2)当量为2111.7 kg和1054.9 kg。EAF工艺的资源消耗、能源消耗、温室气体排放均优于BF-BOF工艺,分别低70.1%,51.0%和50.1%。EAF工艺的3类环境损害均低于BF-BOF工艺,具有一定的环境优势。因此,在条件允许的情况下,增加EAF工艺的生产比例,将有助于汽车制造业和钢铁工业的低碳可持续发展。

Driven by"carbon peak and carbon neutrality",automobile manufacturing industry is an important part of energy saving and carbon reduction.As a resource and energy intensive industry,it uses automobile steel plate as the main material,which has the typical characteristics of high production energy consumption and emissions.The life cycle assessment(LCA)method was used to conduct environmental impact assessment and contribution analysis for each stage of the long process(BF-BOF)and short process(EAF)of automobile steel plate production.The results show that in BF-BOF,the iron making process and sintering process have greater contribution to the total environmental impact.In automotive steel plate production short process(EAF),iron making process and electric furnace steelmaking process contribute greatly to the total environmental impact.The environmental impacts of EAF process in automobile steel plate production are lower than those of BF-BOF process.Global warming(GWP),fossil energy depletion(FFP),mineral resource depletion(SOP),freshwater eutrophication(FEP),marine eutrophication(MEP),freshwater ecotoxicity(FETP),human carcinogenic toxicity(HTPc),and human non-carcinogenic toxicity(HTPnc)are the major environmental impacts.The copper equivalent of BF-BOF process and EAF process are 85.6 kg/t and 25.6 kg/t,respectively,and the comprehensive energy consumption is 541 kg/t and 265 kg/t,respectively.The carbon dioxide equivalent was 2111.7 kg/t and 1054.9 kg/t.The resource consumption,energy consumption and greenhouse gas emission of EAF process are better than those of BF-BOF process,which are 70.1%,51.0%and 50.1%lower,respectively.The three types of environmental damage of EAF process are lower than that of BF-BOF process,which has certain environmental advantages.Therefore,if conditions permit,increasing the production proportion of EAF process will contribute to the low-carbon and sustainable development of automobile manufacturing and steel industry.