太阳能级多晶硅生命周期环境影响评价

采用生命周期评价法对太阳能级多晶硅生产过程的环境影响进行评价. 基于Eco-Indicator99,建立了适用于我国的终点破坏类影响评价模型(Chinese endpoint damage model,CEDM). 对影响评价模型的资源属性参数进行了本地化研究,核算出以2010年为基准年、以我国为基准区域的资源属性本地化人均年度基准值(4.33×105 MJ). 采用现场和问卷调研的方式获得太阳能级多晶硅所有生命周期阶段的能量物质的输入、输出和环境外排数据,调研样本总产量达到2012年全国产量的80%. 结果表明:从环境影响的最终破坏受体来看,太阳能级多晶硅生命周期环境影响主要集中在对人体健康损害方面,占其整个环境影响的72.31%；其次是对资源衰竭方面的影响,占24.23%；对生态系统的损害最小,仅占3.46%. 在所有环境要素中,电的环境影响最高,占79.48%；其次是蒸汽消耗、工业硅原料,二者分别占13.18%、5.97%. 我国太阳能级多晶硅生命周期环境影响是欧洲平均水平的2倍多,主要是受电力结构所致,但在技术先进性和污染防治水平方面要优于欧洲平均水平. 

Environmental Impacts of Solar Grade Polysilicon Based on Life Cycle Assessment

Life Cycle Assessment (LCA) was conducted to analyze the environmental impacts of solar grade polysilicon. A Chinese endpoint damage model of impact assessment was established based on Eco-Indicator99. The localization of the resource parameters of the impact assessment model was studied, and the localization criterion of resources depletion for China over the year 2007 was calculated to be 4.33×10⁵ MJ/(a·p). The data of mass and energy inputs, outputs and environmental emissions were obtained for all life-cycle stages by site investigation and questionnaire. The total product output of the samples accounted for 80% of the national production in 2012. It showed that from the viewpoint of environmental impacts, the damage to human health presented the greatest contribution to life cycle environmental impacts of solar grade polysilicon, accounting for 72.31% of the total environmental impacts. The second was depletion of resources (24.23%), while the damage to ecosystem quality was the least (3.46%). From the viewpoint of environmental factors, the electric power consumption was the highest of all, accounting for 79.48%, followed by steam consumption and MG(Metalurgical grade) silicon consumption, which accounted for 13.18% and 5.97%, respectively. Compared with the average level in Europe, the environmental impacts of solar grade polysilicon in China were more than twice that in Europe, which was caused by China''s power structure. However, the level of technology and pollution control in China was better than that in Europe.