Department of Chemical and Biological Engineering, Northwestern University, Evanston, Illinois 60208, United States.
Institute for Sustainability and Energy at Northwestern, Northwestern University, Evanston, Illinois 60208, United States.
Environ Sci Technol. 2023 Feb 28;57(8):3402-3414. doi: 10.1021/acs.est.2c08655. Epub 2023 Feb 15.
Demand for graphite will grow with expanding use of lithium-ion batteries in the United States. Much graphite is imported, raising supply chain risks. It is therefore imperative to characterize graphite's sources and sinks. Accordingly, we present the first material flow analysis for natural and synthetic graphite in the U.S. The analysis (for 2018) begins with processed graphite trade and includes graphite production, graphite product trade, manufacturing of end products, end product use, and waste management. It considers 11 end-use applications for graphite, two waste management stages, and three recycling pathways. In 2018, 354 thousand tonnes (kt) of processed graphite were consumed in the U.S., including 60 kt natural graphite and 294 kt synthetic graphite. 145 kt of graphite were traded. Refractories and foundries consumed 56% of natural graphite; 42% of synthetic graphite went into making graphite electrodes. Batteries accounted for 10 and 5% of natural and synthetic graphite consumption, respectively; 78% of total graphite used dissipated into the environment; 22% reached the waste disposal stage of which 71% was landfilled and 29% was recycled; and 59 kt of graphite accumulated in in-use stocks. Recycling more graphite and producing graphite from lignin would favorably influence today's supply chain.
美国对锂离子电池的使用不断扩大,导致对石墨的需求增加。许多石墨是进口的,这增加了供应链的风险。因此,必须对石墨的来源和汇进行描述。为此,我们首次对美国天然石墨和合成石墨进行了物质流分析。该分析(针对 2018 年)从加工石墨贸易开始,包括石墨生产、石墨产品贸易、最终产品制造、最终产品使用和废物管理。它考虑了石墨的 11 种最终用途、两个废物管理阶段和三种回收途径。2018 年,美国共消耗 35.4 万吨加工石墨,其中包括 6 万吨天然石墨和 29.4 万吨合成石墨。有 14.5 万吨石墨进行了贸易。耐火材料和铸造消耗了 56%的天然石墨;42%的合成石墨用于制造石墨电极。电池分别占天然石墨和合成石墨消耗的 10%和 5%;78%的总石墨用量散入环境中;22%达到废物处理阶段,其中 71%被填埋,29%被回收;5.9 万吨石墨积累在使用库存中。更多地回收石墨并从木质素中生产石墨将对当前的供应链产生有利影响。