Study of CO2 emissions in China's iron and steel industry based on economic input-output life cycle assessment

With the growing demand, China's iron and steel industry has obtained rapid development since the 1990s. China's steel output reached 220 million tons for the first time in 2003, becoming the first country whose annual production exceeded 200 million tons. The iron and steel is an industry of high energy consumption, high pollution and high emissions which has attracted deep concern of Chinese government. Previous research has estimated the direct CO2 emissions in individual processes of iron and steel production, while research on the indirect CO2 emissions from the related sectors of the iron and steel industry is scarce. To explore the whole CO2 emissions, this paper evaluates the direct and indirect carbon emissions in the iron and steel industry and carbon emission deduction by building an economic input-output life cycle assessment (EIO-LCA) model based on the latest available data of the input-output extension table in 2010 and China's Energy Statistical Yearbook in 2011. The results show that coke and coal produce the most direct CO2 emissions and raw chemical materials, medical and chemical fiber manufacturing, transportation storage and the postal industry, the electricity heat production and supply industry, nonmetal mineral production, petroleum processing of coke and nuclear fuel processing, coal mining and dressing are the six sectors that produce the largest indirect CO2 emissions among the 35 sectors in the iron and steel industry. Based on the results, we suggest that China should (1) improve the quality of coke and coal, increase the efficiency of coke and coal, coal blending technology and the cokes' strength, and employ the scrap or cities' minerals as main raw materials in the production, and at the same time, the government and enterprises may increase to invest in technology innovation; (2) and use high-strength iron and steel instead of the ordinary one. Meanwhile, the spatial distributions of the six sectors are mainly concentrated in Shandong Province, Jiangsu Province, Zhejiang Province and Shanxi Province. Shandong Province, Jiangsu Province, Zhejiang Province and Shanxi Province may adjust their industrial structure by increasing the proportion of the third industry and accelerating the development of high-tech industries and services.