Greenhouse gas emissions and future development trends of primary aluminum in China

Abstract

Primary aluminum is widely used because of its excellent performance, and world primary aluminum production has increased 2.73 times in the past 20 years, with China increasing up to 13.9 times. China's primary aluminum industry (CPAI) is a high greenhouse gas (GHG) emitting industry and is facing a grim situation to reduce emissions. Therefore, quantifying the GHG emissions of CPAI and exploring future development trends are beneficial to the sustainable development of CPAI. In this study, the emission factor method was used to calculate the GHG emissions of CPAI from 2000 to 2020. The result shows that GHG emissions increased dramatically from 65.85 Mt CO2-eq in 2000 to 460.32 Mt CO2-eq in 2020, a seven-fold increase. GHG emissions from aluminum smelting were 363.62 Mt CO2-eq in 2020, which was the largest sub-process of emissions in CPAI, with a high share of 79%. Electricity emissions were the largest source of GHG emissions, accounting for more than 60%, with a maximum of 70.5%. The intrinsic drivers of GHG emissions were explored by the Log-Mean Divisia Index (LMDI) method, and the results showed that primary aluminum production was the largest driver of GHG emissions promotion, while energy intensity was the most important driver of GHG emissions suppression in the last decade. In this study, a modified “S" shaped mathematical model was used to predict the primary aluminum production, which laid the foundation for the subsequent analysis of emission reduction potential. On this basis, five types of scenarios were set based on the results of the driving force analysis. Finally, based on the results of our analysis, we propose strategies for low-carbon development in the primary aluminum industry, including the use of clean energy, and the development of new low-carbon technologies.