Carbon and air pollutant emissions from China's cement industry 1990–2015: trends, evolution of technologies, and drivers

摘要

China is the largest cement producer and consumer in the world. Cementmanufacturing is highly energy-intensive and is one of the major contributorsto carbon dioxide (CO2) and air pollutant emissions, which threatensclimate mitigation and air quality improvement. In this study, we investigatedthe decadal changes in carbon dioxide and air pollutant emissions for theperiod of 1990–2015 based on intensive unit-based information on activityrates, production capacity, operation status, and control technologies whichimproved the accuracy of the cement emissions in China. We found that, from1990 to 2015, accompanied by a 10.3-fold increase in cement production,CO2, SO2, and NOx emissions from China's cementindustry increased by 627 %, 56 %, and 659 %, whereas CO,PM2.5, and PM10 emissions decreased by 9 %, 63 %,and 59 %, respectively. In the 1990s, driven by the rapid growth of cementproduction, CO2 and air pollutant emissions increasedconstantly. Then, the technological innovation in production of replacingtraditional shaft kilns with the new precalciner kilns equipped withhigh-efficiency control facilities in the 2000s markedly reducedSO2, CO, and PM emissions in the cement industry. In 2010,nationwide, 39 % and 31 % of the nationwide PM2.5 andNOx emission were produced by 3 % and 15 % of the total capacityof the production lines, indicating the disproportionately high emissions from asmall number of the super-polluting units. Since 2010, the growing trend ofemissions has been further curbed by a combination of measures, includingpromoting large-scale precalciner production lines and phasing out small ones,upgrading emission standards, installing low NOx burners (LNB), andselective non-catalytic reduction (SNCR) to reduce NOx emissions, as wellas adopting more advanced particulate matter control technologies. Our studyhighlights the effectiveness of advanced technologies on air pollutantemission control; however, CO2 emissions from China's cementindustry kept growing throughout the period, posing challenges to futurecarbon emission mitigation in China.