基于LCA的钢铁联合企业CO_2排放影响因素分析

Analysis of factors influencing CO_2 emissions in an integrated steel works based on Life Cycle Analysis (LCA)

钢铁企业是CO2排放大户,减少吨钢CO2排放是钢铁企业节约能源、保护环境、走可持续发展道路的必然要求.本研究旨在对钢铁企业产品生命周期清单研究的基础上,识别钢铁企业CO2排放的主要影响因素,提出针对性的减排建议.以某钢铁联合企业的产品生命周期清单模型为平台,同时利用TornadoChart工具,计算得到对企业CO2排放影响较大的因素,然后提出了相应的减排措施.结果表明,转炉流程对于钢铁企业的影响要大于电炉流程;对该企业CO2排放有重大影响和相关影响的因素有:高炉煤气(BFG)的CO2排放系数、连铸坯的钢水单耗、热轧的板坯单耗、转炉的铁水比.减少钢铁联合企业CO2排放的有效措施是采取捕集BFG中的CO2、降低转炉的铁水比、加强副产煤气的回收以及优化企业的产品生产结构.

The amount of CO2 emission in steel works occupies a great share of the total industry CO2 emissions in China.Reducing CO2 emission in steel works is urgent for energy saving,environmental protection and sustainable development.This study aims at identifying the main factors resulting in CO2 emissions in steel works and proposing countermeasures based on the study of the life cycle inventory （LCI） of iron and steel products.A certain integrated steel works is taken as an example of LCI analysis by use of the Tornado Chart Tool.Through computations and analyses,it is found that the Electric Furnace Route has less environmental impact than that of the Basic Oxygen Furnace （BOF） Route.The top important CO2 emission factors of the factory are CO2 emission factor of Blast Furnace Gas （BFG）,liquid steel consumption coefficient of continuous casting,continuous casting slab consumption coefficient of hot rolling and hot metal ratio of steelmaking.Corresponding effective measures for CO2 emission reduction such as removing CO2 contained in BFG,decreasing the hot metal ratio of BOF,recycling BFG,and optimizing the product structure are thus proposed.