SONG Lulu, XIONG Xiaoping, CHEN Weiqiang
The recycling of renewable resources is a feasible, cost-controllable, replicable and popularizable carbon emission reduction scheme, which is a strong support for achieving sustainable development and carbon neutrality. In view of the lack of quantitative assessment of carbon emission reduction potential of renewable resources recycling, this study evaluates the recycling potential of bulk material resources, including cement, sand, gravel, brick, lime, glass, rubber, wood, plastics, asphalt, steel, aluminum and copper. In particular, the carbon emission reduction path and carbon neutralization potential of the steel and cement industries with "high energy consumption, high emission and high output" were sorted out and quantitatively assessed. The calculation results show that the demand for bulk material resources will continue to decrease after reaching the peak around 2025, and the amount of scrapped material resources will increase after 2030. The amount of scrapped material resources will reach about 5.46 billion tons per year in 2060, and the proportion of construction waste will be as high as 90% and concentrated in the southeastern coastal provinces. From 2019 to 2060, the reduction of demand for bulk material resources has led to the continuous reduction of carbon emissions. If the circular economy strategies are coordinated, the CO2 emissions in 2060 will be reduced to 430 million tons per year, 77% lower than the emission level in 2018. Among them, the recycling of scrap metals, especially scrap iron and steel, has the greatest potential for CO2 emission reduction. If the recycling rate of scrap iron and steel is increased to more than 90% in 2060, the carbon emissions of the iron and steel industry in 2018 will be reduced by 90%, and the carbon emissions will be reduced by 440 million tons. In contrast, due to the limitation of recycling technology and product recycling value, cement production can only achieve CO2 emission reduction by improving resource efficiency and prolonging product service life. Finally, this study describes the resource recycling policies, models and technologies that need to be deployed during the "14th Five-Year Plan" period as the key period and window period to promote the recycling of renewable resources. Our study provides important support for the realization of carbon neutrality goals.
