TY - JOUR
T1 - Atmospheric Chemistry of (CF3)2CF-C≡N
T2 - A Replacement Compound for the Most Potent Industrial Greenhouse Gas, SF6
AU - Andersen, Mads Peter Sulbæk
AU - Kyte, Mildrid
AU - Thirstrup Andersen, Simone
AU - Nielsen, Claus J.
AU - Nielsen, Ole John
PY - 2017/2/7
Y1 - 2017/2/7
N2 - FTIR/smog chamber experiments and ab initio quantum calculations were performed to investigate the atmospheric chemistry of (CF3)2CFCN, a proposed replacement compound for the industrially important sulfur hexafluoride, SF6. The present study determined k(Cl + (CF3)2CFCN) = (2.33 ± 0.87) × 10–17, k(OH + (CF3)2CFCN) = (1.45 ± 0.25) × 10–15, and k(O3 + (CF3)2CFCN) ≤ 6 × 10–24 cm3 molecule–1 s–1, respectively, in 700 Torr of N2 or air diluent at 296 ± 2 K. The main atmospheric sink for (CF3)2CFCN was determined to be reaction with OH radicals. Quantum chemistry calculations, supported by experimental evidence, shows that the (CF3)2CFCN + OH reaction proceeds via OH addition to −C(≡N), followed by O2 addition to −C(OH)═N·, internal H-shift, and OH regeneration. The sole atmospheric degradation products of (CF3)2CFCN appear to be NO, COF2, and CF3C(O)F. The atmospheric lifetime of (CF3)2CFCN is approximately 22 years. The integrated cross section (650–1500 cm–1) for (CF3)2CFCN is (2.22 ± 0.11) × 10–16 cm2 molecule–1 cm–1 which results in a radiative efficiency of 0.217 W m–2 ppb–1. The 100-year Global Warming Potential (GWP) for (CF3)2CFCN was calculated as 1490, a factor of 15 less than that of SF6.
AB - FTIR/smog chamber experiments and ab initio quantum calculations were performed to investigate the atmospheric chemistry of (CF3)2CFCN, a proposed replacement compound for the industrially important sulfur hexafluoride, SF6. The present study determined k(Cl + (CF3)2CFCN) = (2.33 ± 0.87) × 10–17, k(OH + (CF3)2CFCN) = (1.45 ± 0.25) × 10–15, and k(O3 + (CF3)2CFCN) ≤ 6 × 10–24 cm3 molecule–1 s–1, respectively, in 700 Torr of N2 or air diluent at 296 ± 2 K. The main atmospheric sink for (CF3)2CFCN was determined to be reaction with OH radicals. Quantum chemistry calculations, supported by experimental evidence, shows that the (CF3)2CFCN + OH reaction proceeds via OH addition to −C(≡N), followed by O2 addition to −C(OH)═N·, internal H-shift, and OH regeneration. The sole atmospheric degradation products of (CF3)2CFCN appear to be NO, COF2, and CF3C(O)F. The atmospheric lifetime of (CF3)2CFCN is approximately 22 years. The integrated cross section (650–1500 cm–1) for (CF3)2CFCN is (2.22 ± 0.11) × 10–16 cm2 molecule–1 cm–1 which results in a radiative efficiency of 0.217 W m–2 ppb–1. The 100-year Global Warming Potential (GWP) for (CF3)2CFCN was calculated as 1490, a factor of 15 less than that of SF6.
U2 - 10.1021/acs.est.6b03758
DO - 10.1021/acs.est.6b03758
M3 - Journal article
C2 - 27936633
SN - 0013-936X
VL - 51
SP - 1321
EP - 1329
JO - Environmental Science & Technology (Washington)
JF - Environmental Science & Technology (Washington)
IS - 3
ER -