ABSTRACT
Road transport is the primary source of greenhouse gas emissions in China's transportation field. As an important means to achieve the "double carbon" goal in the transportation field, the new energy automobile industry will face a large number of power battery scrapping in the future. In order to quantitatively assess the carbon emission reduction benefits generated by the spent ternary lithium-ion battery waste recycling industry, the carbon footprint accounting model of spent ternary lithium-ion battery waste recycling and utilization was constructed from the life cycle perspective. By optimizing the power structure and transportation structure, the carbon emission reduction potential of spent ternary lithium-ion battery waste recycling was predicted and evaluated. In addition, the uncertainty analysis was conducted using the propagation of uncertainty equation to ensure the reliability and effectiveness of the carbon footprint results. The results showed that the current carbon footprint of Chinese enterprises using wet technology to recover 1 kg waste lithium batteries was -2 760.90 g (directional recycling process) and -3 752.78 g (recycling process), and the uncertainty of the carbon footprint was 16 % (directional recycling process) and 15 % (recycling process), respectively. From the analysis of carbon emission contribution, the regenerated product stage was the primary source of carbon reduction in the wet recycling and utilization of waste ternary lithium batteries, whereas the battery acquisition, disassembly, and end treatment stages were the main sources of carbon increase. Compared to optimizing the transportation structure, optimizing the power structure could effectively achieve greater carbon emission reduction potential. Under the collaborative optimization scenario, compared to that before optimization, 14 %-19 % carbon emission reduction could be achieved. Compared with native products, the directional circulation process and recycling process could achieve 9 % and 11 % emission reduction potential, respectively.
ABSTRACT
The steel industry is one of the most carbon-intensive industries in China. To analyze the carbon emission and carbon reduction potential of the steel industry in the life cycle, a carbon emission accounting model was built from the perspective of the life cycle. Taking the year 2020 as an example, an empirical analysis was carried out to predict and evaluate the carbon reduction potential of the steel industry in the life cycle by optimizing four variables, namely, scrap usage, fossil fuel combustion, electric power carbon footprint factor, and clean transportation proportion. At the same time, sensitivity analysis was used to determine the key degree of factors affecting carbon emission reduction in the life cycle of steel. The results showed that in 2020, the total life cycle CO2 emissions of the steel industry in China was approximately 2.404 billion tons, of which the acquisition and processing of raw materials were the key links in the carbon emissions of the steel industry, accounting for more than 98% of the total life cycle CO2 emissions of the steel industry. From the analysis of CO2 emission source categories, fossil fuel savings and outsourcing power cleaning were the top priorities of carbon reduction in the steel industry. By 2025, the steel industry could achieve 20%, 6%, 5%, and 1% carbon emission reduction potential by respectively promoting low-carbon technology, optimizing the power structure, increasing the number of steel scraps, and increasing the proportion of clean transportation. The fossil fuel combustion had the most significant impact on the life cycle CO2 emissions of the steel industry, followed by the electric power carbon footprint factor and scrap steelmaking usage. With regard to low-carbon technologies in the steel industry, in the short term, the promotion of low-carbon technologies in the steel rolling process and blast furnace ironmaking process should be the main focus. Later, with the gradual increase in the proportion of electric furnace steelmaking, the promotion of low-carbon technologies in the electric furnace steelmaking process will significantly improve the carbon emission reduction potential of the steel industry throughout its life cycle.
