Comparison of greenhouse gas emission accounting methods for steel production in China

Steel production is an environmentally sensitive process accounting for 10% of greenhouse gas (GHG) emissions in China, which represents 4-5% of the world's total anthropogenic GHG emissions. This study presents and compares three GHG emissions accounting methods for steel production in China, which are the Intergovernmental Panel on Climate Change (IPCC) method, the Life Cycle Inventory Localization (LCIL) method, and the Comprehensive Energy Consumption (CEC) method. Different criteria such as sources of data, energy input-based and process-based analyses, and benefits and limitations of the three methods are compared and discussed. On the basis of the data collected and system boundary defined in this study, the total GHG emissions of the IPCC, LCIL, and CEC methods are estimated as 1.717, 1.715, and 1.959 kg CO2-e/kg steel, respectively. The results of the IPCC and CEC methods show that the coal and coke combustion contributes 90.2% and 84.5% of total energy related GHG emissions during steel production in China, respectively. For the LCIL method, it quantifies the GHG emissions from each individual sub-processes associated with the sintering process to the electric arc furnace process. The results of the LCIL method indicate that the hotspot area for GHG emissions during steel production is the blast furnace process, which accounts for 78.4% of the total energy related GHG emissions. These three methods can be applied to other countries to investigate their GHG emissions. Moreover, the comparison of these three methods provides insights for adopting appropriate methods to calculate GHG emissions for steel production.