Experimental Determination of the Global Warming Potential of Carbonyl Fluoride (COF2)

Abstract

Carbonyl fluoride (COF2) has gained interest as a low-GWP replacement candidate for the high-GWP fluorinated gases employed in semiconductor and display manufacturing. In this study, the infrared absorption cross-section of COF2 was experimentally measured using Fourier Transform Infrared (FTIR) spectroscopy, and its radiative efficiency was determined to be 0.119 W m−2 ppb−1 using the stratospheric-adjusted Pinnock curve. Atmospheric e-folding lifetimes derived from exponential decay measurements were 7.56 h in dry O2 and 54.86 and 36.67 min under low- and high-humidity ambient air, respectively. Incorporation of these lifetimes into the absolute GWP framework yielded GWP100 values of 4.05×10-4 (dry air), 6.82×10-6 (low humidity), and 3.16×10-6 (high humidity), demonstrating that rapid hydrolysis in the presence of water vapor suppresses the climate impact of COF2 to effectively zero under typical tropospheric conditions. Because CO2 is the terminal atmospheric degradation product, the long-term climate impact of COF2 emissions is equivalent to releasing only the stoichiometrically corresponding amount of CO2. These findings provide a fully experimental basis for determining the GWP100 of COF2 under atmospherically relevant conditions and demonstrate that its GWP100 is effectively near zero. This experimentally validated assessment confirms that COF2 is a viable low-GWP replacement gas for chamber-cleaning applications in semiconductor and display manufacturing.