Objective. Cement industry is one of the key sources of air pollution and it is an energy intensive industry. Life cycle impact assessment (LCIA) is one of the basic steps in life cycle assessment methodology (LCA). At first, based on the method of LCA, this paper presents a comparative study of the LCIA of different life cycle inventories (LCI) for the cement industry of whole China for year 2008. This also discusses LCA for 22 individual provinces, 5 autonomous regions and 4 municipalities in China for the year 2008. Second, a regional based comparative study of life cycle impact (LCIA) of different air pollutants and CO
2 was conducted using CML methodology developed by Leiden University. Finally, based on the results of the LCIA, the policies of pollution reduction for Chinese cement industry were proposed.
Results and Discussion. In average emissions of CO
2, SO
2, NO
x, CO, CH
4, NMVOC(non-methane volatile organic compounds), PM(particulate matter), N
2O, As, Cd, Cr, Hg, Ni, Pb, V and Zn were 831, 1.36, 1.65, 0.49, 0.27, 0.19, 3.15, 1.30 × 10
−3, 4.74 × 10
−4, 1.49 × 10
−6, 2.08 × 10
−5, 2.10 × 10
−5, 3.52 × 10
−5, 2.26 × 10
−4, 3.56 × 10
−4, 3.13 × 10
−4 kg per ton of cement. The total environmental value of seven impact categories of the whole China related to cement manufacturing was in order of GWP>HT>AP>NP>POCP>ECT>ECA (GWP: global warming potential, HT: human toxicity, AP: acidification potential, NP: nutrification potential, POCP: photochemical ozone creation potential, ECT: ecotoxicological classification factor for terrestrial ecosystems, ECA: ecotoxicological classification factor for aquatic ecosystems). Moreover, the total environmental value of seven impact categories for 22 individual provinces, 5 autonomous regions and 4 municipalities in China was also analyzed in this paper. The environmental value of seven impact categories for Xinjiang Uyghur autonomous region, Chongqing municipality, Qinghai province, Guizhou province, Hunan province, Guangxi province, Anhui province, Jiangxi province was in order of HT>GWP>AP>NP>POCP>ECT>ECA. For other remaining regions in China, it was in order of GWP>HT>AP>NP>POCP>ECT>ECA.
Conclusions. This paper has collected the inventory data for cement industry in different regions in China and then estimated unit emission factors separately for each region. Finally, CML methodology was used to evaluate the total environment impact and the following conclusions have been drawn. (1) There is a large technological gap among the cement industry of Chinese regions. (2) Reduction potential of CO
2, SO
2, NO
x and PM is very large. (3) Global warming and human toxicity have given the worst impact on environment. Therefore, the authors recommend that China should impose the regulations and detailed reduction targets for the regional cement industry in the future. Those regulations might encourage the Chinese cement producers to develop technologies for CO
2 reduction such as waste heat recovery, alternative raw materials, and alternative fuels. In order to reduce the toxic effects on the human body due to PM, SO
2, NO
x, CO and heavy metals, China should increase the use of dust collectors and desulfurization equipments, and technologies of energy conservation. CO
2 and air pollution reduction in cement industry is still a great challenge for China.
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