Current Sources of Carbon Tetrachloride (CCl4) in Our Atmosphere

Sherry, David ; McCulloch, Archie ; Liang, Qing ; Reimann, Stefan ; Newman, Paul

关键词: CARBON TETRACHLORIDE;    CHLORINE COMPOUNDS;    EMISSION;    OZONE DEPLETION;    GLOBAL AIR POLLUTION;    INTERNATIONAL LAW;    METHANE;    PRODUCTION MANAGEMENT;   

RP-ID  :  GSFC-E-DAA-TN54270

学科分类：污染

美国|英语

来源: NASA Technical Reports Server

【 摘 要 】

Carbon tetrachloride (CCl4 or CTC) is an ozone-depleting substance whose emissive uses are controlled and practically banned by the Montreal Protocol (MP). Nevertheless, previous work estimated ongoing emissions of 35 Gg year−1 of CCl4 into the atmosphere from observation-based methods, in stark contrast to emissions estimates of 3 (0-8) Gg year−1 from reported numbers to UNEP under the MP. Here we combine information on sources from industrial production processes and legacy emissions from contaminated sites to provide an updated bottom-up estimate on current CTC global emissions of 15-25 Gg year−1.We now propose 13 Gg year−1 of global emissions from unreported non-feedstock emissions from chloromethane and perchloroethylene plants as the most significant CCl4 source. Additionally, 2 Gg year−1 are estimated as fugitive emissions from the usage of CTC as feedstock and possibly up to 10 Gg year−1 from legacy emissions and chlor-alkali plants.