Calculation of Global Warming Potential of Refrigerants Using Quantum Chemical Calculations

Abstract

Various physical properties have been vigorously investigated for the urgent need to shift to refrigerants with low global warming potentials. Although the measurement of global warming potential has progressed, a simple prediction method will be useful in considering new candidate substances. Quantum chemical calculations were performed for the conventional refrigerants R23, R32, and the ethylene derivatives R1123, R1132a, R1132(E), and R1132(Z). The radiative efficiencies were 10% to 60% higher than the measured. The atmospheric lifetimes were estimated from a newly developed correlation, confirmed between the energy barrier obtained at M06-2X/aug-cc-pVTZ and the rate constant at 272 K. Although the lifetime of R23 was predicted to be 116 years longer than that of the other derivatives, the other predicted lifetimes were consistent within one year for an atmospheric lifetime of approximately ten years. The calculation was matched within a factor of 0.76 to 1.35, even for a lifetime shorter than 0.1 years. The GWPs calculated above were consistent with the IPCC reported within ±50%. However, the GWP of R1132(E) was 2.24 times higher than the literature value.