应用LCA分析中国典型钢铁企业的环境负荷

为得到钢材的环境负荷,基于生命周期评价方法对中国典型钢铁企业中不同流程中的各工序,系统、定量地分析评价环境负荷.采用GaBi 4.3软件提供的CML2001环境影响分类方法,将各工序的环境影响进行分类,并根据特征化因子,分析生产1 t钢材产生的环境影响.分析结果表明:长流程生产过程主要的环境影响是焦化、烧结、高炉炼铁和废钢回收环节产生的水生生态毒性、人体毒性、化石能源耗竭和矿产资源耗竭等.其中,长流程的炼钢过程对气候变化、人体毒性、水生生态毒性和固体废弃物的影响较大,分别约占该类型总环境影响值的30%,95%,50%和90%;短流程生产过程主要的环境影响为铁水和电炉炼钢过程产生的气候变化、酸化和光化学臭氧形成等.该研究结果可为钢铁企业调整两种不同流程提供一定的理论依据,有助于准确发现生产过程中各环节节能降耗、降低环境负荷的潜力所在,从而有利于钢铁企业对生产流程进行改进或优化.

Life cycle assessment of integrated iron and steel works in China

Based on the data from a steel company, this paper applied life cycle assessment and GaBi 4.3 to analyze the material, energy consumption and emission during production of 1 t on steel by CML2001 method was used to perform environmental impact assessment of steel production. The results showed that the major environmental impact of BF-BOF steelmaking process includes aquatic ecotoxicity, human toxicity, fossil energy depletion and mineral resource depletion from coking, sintering, blast furnace and steel scrap recycling. And climate change, human toxicity, aquatic ecotoxicity, solid waste take up 30%, 95%, 50% and 90% of the total environmental impact, respectively. The major environmental impact of electric furnace steelmaking process includes mainly climate change, acidification and photochemical ozone formation from the molten iron and electric steelmaking processes. So a reliable basis of for decision making for iron and steel enterprises to adjust two different processes is provided. And the research helps to accurately discover energy saving, reduce the potential for environmental load in various aspects of the production process, thus contribute to iron and steel enterprises to improve or optimize production processes.