冶金法制备太阳能级多晶硅的生命周期评价研究

Life Cycle Assessment of Solar Grade Multi-Crystalline Silicon Preparation by Metallurgical Method

运用生命周期评价(LCA)方法对冶金法制备太阳能级多晶硅的生产过程环境负荷进行了研究,得到了生产1 000 kg冶金法太阳能级多晶硅的具体环境负荷和1 kg冶金法太阳能级多晶硅的生命周期环境综合影响值.研究表明:生产1 000 kg冶金法太阳能级多晶硅的具体环境负荷为4 178 kg硅石、26 609 kg ce、149 552 kg CO_2、631.6 kg SO_2、352 kg粉尘、12.67 kg CFC-11(氟利昂)、0.161 2 m3填埋空间、57 416.9 kg非致癌有毒物;1 kg冶金法太阳能级多晶硅的生命周期环境综合影响值为31.91,其中最大的环境影响为全球变暖影响(GWP),占综合影响的67.4%;冶金法的主要环境负荷源于火电消耗,应该主要从减少生产过程中电力消耗的角度进行改善评价.

The method of life cycle assessment（ LCA） is applied to investigating the environmental load of preparation of solar grade multi- crystalline silicon by metallurgical method. The environmental load of preparation of1 000 kg solar grade multi- crystalline silicon by metallurgical method and the comprehensive life- cycle environmental implication of 1 kg solar grade multi- crystalline silicon by metallurgical method are obtained. The research shows： the specific environmental load of the production of per 1 000 kg solar grade multi- crystalline silicon by metallurgical method is 4 178 kg of silica,26 609 kg of ce,149 552 kg of CO2,631. 6 kg of SO2,352 kg of dust,12. 67 kg of CFC- 11（ Freon）,0. 161 2 m^3 of landfill space and 57 416. 9 kg of non- carcinogenic toxic; the comprehensive life- cycle environmental implication of per 1kg of solar grade multi- crystalline silicon by metallurgical method is 31. 91. in which the greatest is environmental implication of global warming potential（ GWP）,accounting for 67. 4%. The main environmental load of metallurgical method is the result of thermal power consumption,therefore,it is recommended that improvement evaluation should be mainly conducted through reducing power consumption in the process of production.