Plant-Level Emissions and Synergistic Control of Pollutants and Carbon Dioxide in China's Cement Industry Based on Real-Time Monitoring Data

The cement industry is a major source of air pollutants and carbon dioxide (CO₂), threatening air quality and climate change. To reduce such emissions, China has introduced a set of ambitious synergistic control policies targeting cement-related emissions. This study evaluated the impacts of emission policies and projected future reduction potentials by constructing a nationwide, smokestack-level, hourly frequency emissions database for China's cement industry, covering approximately 92%–96% of Chinese cement plants (including a total of 1,382–1,491 production lines from 1,054–1,124 cement clinker plants) during 2021–2023. The results demonstrated that policies implemented between 2020 and 2023 led to reductions of 38.2%, 19.1%, 31.6%, and 18.4% for particulate matter (PM), sulfur dioxide (SO₂), nitrogen oxides (NO_x), and CO₂, respectively. Notably, 90% of plants already met the 2024 ultra-low emission (ULE) standards for PM and SO₂, but only 26.3% complied with the ULE standards for NO_x. Furthermore, our results revealed that adopting multiple abatement measures plays a critical role in capturing the co-benefits of pollutants and CO₂ emissions reduction. If all remaining plants adopt co-processing technology, install and upgrade high-efficiency emission control equipment, improve energy efficiency, and further eliminate outdated production capacity, they could synergistically reduce 9.8%–67.4% of pollutants and CO₂ emissions and increase the proportion of synergy index (SI) > 0 (indicating a synergistic trend between pollutants and CO₂ emissions) values by 2.8%–21.7%. This study provides evidence for air pollution and climate mitigation in China and offers insights for other countries looking to reduce emissions from the cement industry.