中国水泥熟料排放系数差异性及区域减排策略选择

Differences in the emission coefficients of cement clinkers and selection method for regional emission reduction

水泥熟料是主要的CO_2排放源,其排放系数受原料种类和品质、生产工艺、生产规模等多种因素的影响。分析中国各地区熟料排放的差异性、减排潜力和策略选择,可以为区域降低熟料排放的方法和政策选择提供决策支持。本文以全国22省市中182条新型干法生产线和75条立窑生产线为样本,对中国水泥熟料排放系数差异性进行了分析,结论认为:(1)生产工艺的排放差异:立窑熟料排放系数高于新型干法;(2)生产规模的差异:随着生产规模的增加,燃料排放、电力排放呈现降低的趋势,而工艺排放则不受此影响;(3)熟料排放系数呈现从东部沿海向西部内陆逐渐增加的态势,从熟料排放系数构成来看,熟料高MgO含量将导致高的工艺排放,原料替代减排主要集中在钢铁和磷生产集中的华北和西南地区;高寒区域和西南地区也是高能源强度和高燃料排放的区域。论文进一步分析了工艺替代、规模生产和原料替代三种方式在调研省区的减排潜力,根据各种方法减排量所占份额,将驱动区域减排的方式选择归纳为单因素、双因素和均衡发展三种类型。文章认为调研区域应根据三种方式的份额,有目的地选择减排方式和设计相应的减排政策。

Cement is the major industry in greenhouse gas emissions. The emission coefficient of a cement clinker is determined by production process, energy efficiency, and the type and quality of raw materials. We analyze differences in clinker emissions, potential for reductions and strategic options across all regions of China, provide regional approaches and policy options to reduce clinker emissions. Using data from 182 NSP process lines and 75 Shaft kiln lines, we analyzed differences in emission coefficients for production of cement clinkers. In respect of production processes, the emission coefficient of the Shaft kiln process is higher than that of the NSP process; in respect of production scales, the emission coefficient of small-scale production is higher than that of large-scale production. The distribution of regional clinker emission coefficients tends to increase from the eastern coastal to western inland regions of China. The high content of MgO in clinker is mainly distributed in the middle and lower reaches of the Yellow River and the surrounding areas of the Wuyi Mountains. The process emissions in these two regions are also higher than other regions. Northern coastal regions have the highest energy efficiency of clinkers, followed by southern coastal regions; the high-cold regions and Southwest China are characterized by high energy-intensity and high fuel-related emissions. The rates of raw material substitution are relatively high in regions where steel, phosphorite, and coal resources are widely distributed, especially in Guizhou, Yunnan and Hebei. Three methods of emission reduction： process substitution, large-scale production, and raw material substitution are measured to calculate the potential emission reductions in the surveyed regions. In Hebei, Liaoning and Jiangsu, substitute steel slag for limestone is the main reduction method, substitute phosphorous slag is preferred for Hubei, Guangxi, Sichuan, Guizhou and Yunnan. Large-scale production plus raw material substitution is suggested by Shanxi, Anhui, Fujian, Jiangxi, Guangdong and Chongqing. Process substitution plus large-scale production eliminate the outdated process and small-scale production lines are the major reduction methods for Shaanxi and Tibet. While other provinces, such as Inner Mongolia, Shandong and Henan, should apply these three reduction methods equally.