A Study on the Carbon Emissions Calculation Model of Iron and Steel Products Based on EIO-LCA

Abstract

Carbon emission has become a global focus. The construction of carbon emissions calculation model is helpful for its control. Currently, there is still no uniform method about accounting on the carbon emissions of steel products. The common calculation models are not totally suitable for China. To make up for the shortcomings of them, this paper defines the life cycle system of the iron and steel products based on EIO-LCA, measures the quantity of the direct, indirect carbon emissions and carbon emission deduction in various stages of this life cycle, identifies the hotspot and department which contributes most in carbon emission, and takes Hunan Valin Xiangtan Iron and Steel Co., Ltd (abbreviated Xiang Gang) as an example to validate it. It shows that 2103.87kg of carbon in total would be emitted when one tonne of steel is produced by Xiang Gang. Among the total, the quantity of direct, indirect and deductible carbon emission are 2033.5kg, 216.75kg and 146.38kg respectively, namely carbon emissions of producing per ton of steel is 2.1 tons. Direct carbon emissions from all stages of the life cycle of steel products mainly exist in the stage of steel production and transportation. And ferrous metal smelting and rolling processing industry are the largest emissions industries of the total indirect emissions. Converting by-product gas, heat, and pressure into electrical energy use can reduce carbon dioxide emissions by 146kg, which is the equivalent of reducing carbon dioxide emissions per ton of steel 0.15 tons. Therefore, in order to make the carbon dioxide emissions reach the advanced domestic level of 1.7 tons per ton steel, the iron and steel enterprises can meet emissions reduction targets by strengthening control of carbon emission and improving the efficiency of the utilization of secondary energy from small and large scale.