Life cycle assessment considering water-energy nexus for lithium nanofiltration extraction technique

摘要

Lithium is an important strategic resource and the Qinghai-Tibet Plateau possesses abundant liquid lithium resources in the salt lakes. Nanofiltration is a promising technique for lithium extraction from salt-lake brines. However, no information on the environmental impact of lithium nanofiltration extraction is available. This study used life cycle assessment (LCA), life cycle cost (LCC) and water consumption (LCWC) methods to evaluate the environmental burden of lithium nanofiltration extraction technique with the functional unit of 1 kg Li2CO3 products. The results showed that nanofiltration stage was the key process to produce the environment burden based on higher values of global warming potential, acidification potential, photochemical ozone creation potential, soot & ashes, and nutrient enrichment in comparison with the other stages of lithium extraction. Electricity consumption was the major contributor to global warming potential. The total life cycle cost was 18.01 USD with internal cost accounting for 99.99%. Direct water consumption was 22 times higher than indirect water consumption in this process. The water and energy consumption of nanofiltration stage accounted for 98.05% and 53.95% of total consumption, respectively. The total cost of energy and water consumption for nanofiltration technique in different regions followed the order of TibetInner MongoliaSinkiangQinghai. This study provided quantitative data and theoretical basis for lithium resource exploitation in the ecologically-fragile regions in the world. (C) 2020 Elsevier Ltd. All rights reserved.