中国水泥碳排放测算的影响因素分析与不确定度计算

Identification of factors influencing CO_2 emission estimation from Chinese cement industry and determination of their uncertainty

作为水泥生产大国和CO_2排放大户,中国水泥行业的CO_2排放在国际上受到越来越广泛的重视,然而不同的研究结果之间存在不同程度的差异.为了定量研究中国水泥碳排放测算的影响因素,对碳排放因子的测算、运营边界的界定及水泥熟料或水泥成品的产量这3个影响因素做了详细分析,并对碳排放因子的不确定度做了定量计算.结果发现,影响中国水泥碳排放测算的最主要因素是碳排放因子,而该因素又与生产工艺、燃料和熟料水泥比等密切相关.本研究结果比IPCC、EDGAR、CDIAC和WBCSD/CSI等研究结果均低,并且差异逐年显著,以水泥碳排放来自碳酸盐分解的部分为例,2000年相差约65 Mt,而2012年差值接近450 Mt.计算表明,中国水泥碳排放不确定度为12%~22%.因此,水泥碳排放测算的影响因素较多,在计算中国水泥碳排放量时不可照搬国外研究的参数.

As a large contributor of cement production and CO_2 emission,Chinese cement industry has attracted great international attention. However,different studies showed some discrepancies in terms of CO_2 emission estimations from cement production. In order to quantify CO_2 emission factors from Chinese cement industry,three influences have been discussed： calculation of CO_2 emission factors by cement production,definition of the calculation boundary,and the output of clinker or cement product. Furthermore,the uncertainty for CO_2 emission factors has been calculated. It is concluded that CO_2 emission factor is the main factor for CO_2 emission estimation,and it is related to production process,fuel types and clinker/cement ratio. Estimation results from this study are lower than those in IPCC,EDGER,CDIAC and WBCSD/CSI,and the differences become more significant by years. For example,the discrepancies of CO_2 emissions from carbonate decomposition were approximately 65 Mt and 450 Mt in year 2000 and 2012,respectively.The uncertainties of CO_2 emissions from Chinese cement industry range from 12% to 22%. In conclusion,there are many factors influencing CO_2 emissions from Chinese cement industry,and we cannot imitate parameters from other countries when calculating CO_2 emissions from Chinese cement industry.