Gas chromatography methods for the efficient separation of multicomponent refrigerant blends of hydrofluorocarbons and hydrofluoroolefins: R-404A, R-407C, R-410 A, R-507, and R-513A

Hydrofluorocarbon (HFC) regulations have prompted the development of technology, such as extractive distillation using ionic liquids, to separate reclaimed HFC-based refrigerant blends to recover lower Global Warming Potential (GWP) HFCs and repurpose high-GWP HFCs. Multicomponent mixtures, across the entire composition range in reclaimed refrigerants, need to be accurately quantified. Industrial standards on purity (i.e., 99.5 % by weight) are required for future reuse in next-generation refrigerant blends and repurposing HFCs that will be phased out. The present study investigates gas chromatography (GC) methods for analyzing multicomponent refrigerant mixtures R-404A, R-407C, R-410A, R-507, and R-513A. A low-cost GC with a thermal conductivity detector (TCD), various columns, and a sampling injection valve are used to quantify, single refrigerant components difluoromethane (HFC-32), pentafluoroethane (HFC-125), 1,1,1,2-tetrafluoroethane (HFC-134a), 1,1,1,-trifluoroethane (HFC-143a), and the hydrofluoroolefin, 2,3,3,3-tetrafluoroprop-1-ene (HFO-1234yf). The effect of different columns, oven temperature, and carrier gas flow rate was investigated. A rigorous error analysis was performed on the method to determine measurement uncertainties. Results from the proposed method (HayeSep D column) show shorter to similar retention times than traditional methods (Carbopack B column), with standard deviations <0.64 % by weight and 95 % confidence level error of ±0.08 to ±0.8 wt% for all refrigerant mixtures. Shorter analysis time, lower GC operating temperatures, and less expensive supplies (e.g., GC column) are advantages of the proposed methodology. The study provides additional analytical understanding for researchers and the refrigerant manufacturing and reclamation industries. • HayeSep D provides shorter or similar retention times compared to Carbopack B for R-404A, R-407C, R-410A, R-507, and R-513A. • Calibration curves were prepared for HFC-32, HFC-125, HFC-134a, HFC-143a, and HFO-1234yf using a TCD and a sampling valve. • The study provides refrigerant reclaimers with an alternative option for analyzing refrigerant mixtures.