Investigation on absorption separation characteristics of R134a, R1234yf, R22, R410A, and R404A using MWCNT-[HMIM][Tf2N] ionanofluid

In this study, refrigerant absorption characteristics of R134a, R1234yf, R22, R410A, and R404A were investigated using MWCNT-[HMIM][Tf2N] ionanofluid (IONF) for environmental improvement towards a sustainable future. During the absorption experiment, the remaining free volume space was reduced when the refrigerant was recharged in Cycle-2, and the average pressure reduction rate in Cycle-1 was increased by 18.2 % compared to Cycle-2. In addition, the solubility between the refrigerant and IONF had a more significant influence on the absorption performance than the concentration. The relative refrigerant absorption performance for the separation of mixed refrigerants increased by interfering with the absorption of refrigerants with relatively large molecular sizes as the concentration of IONF increased. Compared to 0 wt%, the relative absorption performance at 0.5 wt% concentration of MWCNT-[HMIM][Tf2N] IONF increased by 123.9 %, 26.4 %, and 123.9 %, respectively, for R22/R134a, R22/R1234yf, and R134a/R1234yf. It was confirmed that the refrigerant recovery and waste refrigerant treatment using MWCNT-[HMIM][Tf2N] IONF have sufficient potential to reduce environmental degradation and considered to be aneconomically viable method.