Technologies for CO2 emission reduction and low-carbon development in primary aluminum industry in China: A review

As a typical energy-intensive industry, the primary aluminum industry (PAI) is the third largest source of greenhouse gas (GHG) emissions, followed by the electricity and steel industries. GHG emissions of PAI exceed those of the other non-ferrous metal sectors, accounting for more than 3 % of total global emissions. As the largest producer and consumer of primary aluminum (accounting for 57 % of the global amount), China bears an important responsibility for energy conservation and emission reduction. This review aims to discuss low-carbon strategies and technology improvement related to PAI, with an emphasis on their potential, cost, and development prospects. This study established an analytical framework, based on life cycle assessment (LCA) that considered factors reported in related literature, for the design of strategies for reducing GHG emissions in China's PAI. The LCA-based carbon dioxide-equivalent (CO2e) emissions per ton (t) of primary aluminum and secondary aluminum were estimated to be 14.98 t and 0.32 t, respectively. This indicated that the CO2e emission of recycling process was only approximately 2 % of that of normal process. China's PAI exhibits considerable potential for emission reduction, with its peak being scheduled to be achieved by 2030. The potential to be tapped mainly includes clean energy, waste aluminum recycling, and low-carbon technology. This study suggests that the focus of China's PAI should be on cost-effective technology improvement in the short term, on power decarbonization and aluminum-scrap recycling in the medium term, and on technologies with a higher cost but better emission reduction in the long term.