Comprehensive analysis of refrigerant R134a: Implications for estimating and managing greenhouse gas emissions

Abstract

This study introduces a comprehensive analytical method for assessing refrigerant purity, offering various insights into accurate and precise estimations of greenhouse gas (GHG) emissions and the reclamation of refrigerants. Samples of three different states of CH2FCF3 (R134a), namely recovered R134a, reclaimed R134a, and new R134a, were prepared and analyzed for all impurities. Non-condensable gases (O2, N2, CH4, CO, and H2) were analyzed using gas chromatography (GC) with a thermal conductivity detector (TCD) and a pulsed discharge detector (PDD), and unidentified complex compound impurities containing C, H, Cl, and F were investigated using GC with mass spectrometry (MS) and an atomic emission detector (AED). The purities of the three samples were determined by calculating the total quantity of impurities and their uncertainties. The calculated values for the purities of recovered R134a, reclaimed R134a, and new R134a were 953,125.38 µmol/mol (1,272.45 µmol/mol, k = 2), 998,529.67 µmol/mol (31.58 µmol/mol, k = 2), and 998,803.56 µmol/mol (32.50 µmol/mol, k = 2), respectively. The majority of impurities detected were GHGs with high global warming potentials (GWPs) up to 11,200. Certain impurities were found at concentrations exceeding 1,000 µmol/mol. The annual GHG emissions resulting only from R134a impurities in South Korea were approximately 0.01 MtCO2eq. Because of the large number of GHGs in refrigerants, a comprehensive examination of refrigerant impurities is necessary for refrigerant monitoring and GHG inventory management.