Abstract：
Global atmospheric emissions of perfluorocyclobutane (c-C4F8, PFC-318), a potent greenhouse gas, have increased rapidly in recent years. Combining atmospheric observations made at nine Chinese sites with a Lagrangian dispersion model-based Bayesian inversion technique, we show that PFC-318 emissions in China grew by approximately 70% from 2011 to 2020, rising from 0.65 (0.54-0.72) Gg year-1 in 2011 to 1.12 (1.05-1.19) Gg year-1 in 2020. The PFC-318 emission increase from China played a substantial role in the overall increase in global emissions during the study period, contributing 58% to the global total emission increase. This growth predominantly originated in eastern China. The regions with high emissions of PFC-318 in China overlap with areas densely populated with polytetrafluoroethylene (PTFE) factories, implying that fluoropolymer factories are important sources of PFC-318 emissions in China. Our investigation reveals an emission factor of approximately 3.02 g of byproduct PFC-318 emissions per kg of hydrochlorofluorocarbon-22 (HCFC-22) feedstock use in the production of tetrafluoroethylene (TFE) (for PTFE production) and hexafluoropropylene (HFP) if we assume all HCFC-22 produced for feedstock uses in China are pyrolyzed to produce PTFE and HFP. Further facility-level sampling and analysis are needed for a more precise evaluation of emissions from these factories.
摘要：
全氟环丁烷（c-C4F8，PFC-318）的全球大气排放，一种强大的温室气体，近年来增长迅速。将中国9个站点的大气观测与基于拉格朗日色散模型的贝叶斯反演技术相结合，我们显示，中国的PFC-318排放量从2011年到2020年增长了约70％，从2011年的0.65（0.54-0.72）Ggyear-1上升到2020年的1.12（1.05-1.19）Ggyear-1。在研究期间，中国的PFC-318排放增加对全球排放的总体增长起到了重要作用，对全球排放总量增长贡献58%。这种增长主要起源于中国东部。中国PFC-318排放高的地区与聚四氟乙烯（PTFE）工厂密集的地区重叠，这意味着含氟聚合物工厂是中国PFC-318排放的重要来源。我们的调查显示，如果我们假设在中国生产的所有用于原料的HCFC-22都被热解以生产PTFE和HFP，则在生产四氟乙烯（TFE）和六氟丙烯（HFP）中，每千克使用的氢氯氟烃-22（HCFC-22）原料的排放因子约为3.02g。需要进一步的设施级采样和分析，以便更精确地评估这些工厂的排放。
