Are Ionic Liquids Suitable as New Components in Working Mixtures for Absorption Heat Transformers?

Abstract

The working mixture almost exclusively used to operate absorption heat transformers (AHT) is {H2O + LiBr} ({H2O + NH3} can also be used). Unfortunately, both working pairs present some drawbacks: corrosivity, toxicity, crystallization or high working pressure. Ionic liquids (ILs) possess very interesting properties (thermal stability, possible miscibility with water, negligible vapor pressure) that make them good candidates to be used as absorbents in AHT. This paper aims at providing an overview of available thermodynamic data concerning {H2O + IL} mixtures that could be used to operate an AHT.