TITLE:
Characteristics of Absorption Equilibrium with HFC-134a and an Ionic Liquid Pair
AUTHORS:
Takehiro Esaki, Noriyuki Kobayashi, Hiroki Uchiyama, Yousuke Matsukuma
KEYWORDS:
Absorption Chiller Cycle, HFC-134a, Ionic Liquid, Duhring Diagram
JOURNAL NAME:
Journal of Materials Science and Chemical Engineering,
Vol.7 No.3,
March
29,
2019
ABSTRACT: Cold energy generation systems must be improved to prevent catastrophic climate change. In this study, we focused on an absorption chiller cycle with HFC-134a and an ionic liquid pair as the refrigerant and absorbent, respectively. It was expected that this absorption chiller cycle could generate cold heat below 0°C. Two liquids were selected and their absorption equilibrium with this pair was evaluated for the absorption chiller cycle. We measured the adsorbed amount at equilibrium with 1-butyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide [BMIM][Tf2N] and N-trimethyl-N-butylammonium bis(trifluoromethanesulfonyl)imide [N1113][Tf2N]. The experimental results were reproduced using the non-random two liquid (NRTL) model. This analysis model corresponded well in terms of the amount of adsorption at equilibrium with the experimental results. A Duhring diagram was also generated the NRTL model, and the absorption cycle characteristics as a function of temperature were determined. The absorption chiller cycle obtained cold heat at 10°C with a regeneration temperature of 70°C in addition to generating cold heat below 0°C.