在过去的几年里,短命不饱和卤代烃已作为长寿命卤化温室气体和臭氧消耗物质的环保替代品上市。用于各种应用的不饱和卤化碳的相加入,如制冷和发泡,可以通过它们在大气中的出现和增加来跟踪。我们介绍了氢氟烯烃(HFO)HFO-1336mzz(Z)((Z)-1,1,1,4,4,4-六氟-2-丁烯,顺式-CF3CH=CHCF3),一种新使用的不饱和氢氟碳化合物。自2018年以来,HFO-1336mzz(Z)在三个瑞士和一个荷兰地点进行的为期几个月的活动中,在超过90%的所有测量中都被检测到。自2019年以来,在瑞士高海拔少女站连续运行的所有测量数据中,有30%被发现。在污染事件期间,观察到高达10ppt的摩尔分数。根据我们的测量,瑞士和荷兰的排放量估计为2-7Mgyr-1(2019-2021)和30Mgyr-1(2022),分别。建模的空间排放分布仅部分符合这两个国家的人口密度。监测大气中新的不饱和卤代烃的存在至关重要,因为它们的降解产物的长期影响仍存在争议。此外,HFOs的生产涉及气候活性物质,可能泄漏到大气中──在HFO-1336mzz(Z)的情况下,例如,消耗臭氧层的CFC-113a(CF3CCl3)。
For the past few years, short-lived unsaturated halocarbons have been marketed as environmentally friendly replacements for long-lived halogenated greenhouse gases and ozone-depleting substances. The phase-in of unsaturated halocarbons for various applications, such as refrigeration and foam blowing, can be tracked by their emergence and increase in the atmosphere. We present the first atmospheric measurements of the hydrofluoroolefin (HFO) HFO-1336mzz(Z) ((Z)-1,1,1,4,4,4-hexafluoro-2-butene, cis-CF3CH═CHCF3), a newly used unsaturated hydrofluorocarbon. HFO-1336mzz(Z) has been detected in >90% of all measurements since 2018 during multi-month campaigns at three Swiss and one Dutch location. Since 2019, it is found in ∼30% of all measurements that run continuously at the Swiss high-altitude Jungfraujoch station. During pollution events, mole fractions of up to ∼10 ppt were observed. Based on our measurements, Swiss and Dutch emissions were estimated at 2-7 Mg yr-1 (2019-2021) and 30 Mg yr-1 (2022), respectively. Modeled spatial emission distributions only partly conform to population density in both countries. Monitoring the presence of new unsaturated halocarbons in the atmosphere is crucial since long-term effects of their degradation products are still debated. Furthermore, the production of HFOs involves climate-active substances, which may leak to the atmosphere─in the case of HFO-1336mzz(Z), for example, the ozone-depleting CFC-113a (CF3CCl3).