The collaborative pollutants and carbon dioxide emission reduction and cost of ultra-low pollutant emission retrofit in China's cement kiln.

Promoting the ultra-low pollutant emission retrofit of the cement industry, as the third largest industry in terms of air pollutants and carbon dioxide (CO 2) emissions in China, has become an important part of achieving carbon peaking and carbon neutrality. In this work, the current status of pollutant emission in cement industry and the pollutant emission limit value of ultra-low emission retrofit in typical provinces were analyzed. And, the collaborative air pollutants and CO 2 emission reduction potential and cost-benefit were assessed in six types of ultra-low pollution emission retrofit scenarios. The results indicate that the emission reduction of particulate matter (PM)，sulfur dioxide (SO 2) and nitrogen oxides (NOx) in six scenarios are 10%–15%, 1%–5% and 26%–64%, respectively. The construction investment of 43.8 billion Yuan is needed to complete the retrofit of production lines when the pollutant emission limit value is set as 10 mg/m3, 35 mg/m3 and 50 mg/m3 for PM, SO 2 and NOx, which is 6 times of that when the pollutant emission limit value is set as 10 mg/m3, 50 mg/m3 and 100 mg/m3. However, the cost per unit equivalent of pollutant abatement of the former is only 36% of the latter. The emission reduction potential of CO 2 in six scenarios is 0.4%–0.6%, indicating that the ultra-low pollutant emission retrofit in cement kiln has limited effect on CO 2 emission reduction potential. Comprehensive analysis of emission reduction potential and cost-benefit, it is more economical and reasonable for China cement kilns to choose the path of ultra-low emission retrofit in scenario 4. • The production capacity and pollution status of cement kiln were analyzed. • Six ultra-low pollutant emission retrofit scenarios were designed. • Identified the best path of ultra-low emission retrofit in cement industry. • The ultra-low pollutant emission retrofit can reduce pollutants and CO 2 emission. • The retrofit of pollutants and CO 2 emission should be carried out simultaneously. [ABSTRACT FROM AUTHOR]