Synergistic mitigation potential of carbon and air pollutants in China's cement industry:A perspective from material-energy flows

Abstract

Cement industry plays a pivotal role in achieving the carbon neutrality target and air quality improvement in China. However, how low-carbon and ultra-low emission technology transformation synergistically affects carbon and air pollutant emissions remains unclear. Here, coupling the material-energy flow, we developed an integrated assessment framework to track carbon and multiple air pollutants coupling flows in China's cement industry. The whole-process estimates of CO₂eq, Hg, SO₂, PM_2.5, NOx, and VOCs were 9 %–60 % higher than those reported in most previous studies, which may be mainly due to the newly included emissions from mining, transportation, power use, and waste co-processing. Noteworthy, the national cement trade does not help the reduction of national CO₂eq and air pollutants emissions, but enhanced their emissions. We identified Fujian, Jiangsu, and Zhejiang provinces as the major importers of cement product, responsible for transferring over half of their user-based emissions to cement bases. By 2060, China's cement industry was expected to reduce 1262 Mt-CO₂eq, 101 t-Hg, 611 kt-SO₂, 598 kt-PM_2.5, 1167 kt-NOx, and 429 kt-VOCs, respectively. Remarkably, raw materials has limited co-control reduction potential. By contrast, fuel substitution and energy efficiency improvements totally contributed to 27 % of CO₂eq emission reduction and 15 %∼43 % of multiple air pollutants reduction, respectively, which constituted the keys to achieve the synergistic mitigation of carbon and multiple air pollutant emissions in the future.