Eutectic mixtures of ionic liquids in absorption chillers

An absorption chiller comprising a mixture of a refrigerant and an absorbent, and the absorbent is a eutectic mixture of two ionic liquids selected from the group consisting of:

• 1-ethyl-3-methylimidazolium acetate and 1-ethylpyridinium acetate,
• 1-butyl-3-methylimidazolium acetate and 1-butylpyridinium acetate,
• 1-butyl-3-methylimidazolium dimethylphosphate and 1-butylpyridinium dimethylphosphate,
• 1-ethyl-3-methylimidazolium acetate and 1-ethyl-3-methylimidazolium dimethylphosphate,
• 1-ethyl-3-methylimidazolium dimethylphosphate and 1-ethylpyridinium dimethylphosphate,
• 1-ethyl-3-methylimidazolium bromide and 1-ethylpyridinium bromide,
• 1-butyl-3-methylimidazolium bromide and 1-butylpyridinium bromide,
• 1-butyl-3-methylimidazolium bromide and 1-ethylpyridinium bromide,
• tetramethylammonium chloride and 1-ethyl-3-methylimidazolium chloride,
• tetraethylammonium chloride and 1-ethyl-3-methylimidazolium chloride,
• 1-butyl-3-methylimidazolium bromide and 1-butyl-3-methylimidazolium chloride, and
• hexamethylguanidinium acetate and hexamethylguanidinium dicyanamide;
• wherein the concentration ratio of the two ionic liquids in the eutectic mixture is the concentration ratio at the eutectic point of the eutectic mixture.