Ionic Liquids as Sorption Cooling Media

T.J.S. Schubert, T.F. Beyersdorff, S. Sauer, C. Römich, N. Merkel, K. Schaber M. Koch
Iolitec Ionic Liquids Technologies GmbH, DE

Keywords: energy effiency, ionic liquids, CO2 fingerprint


We have shown their use in a sorption cooling device in cooperation with the institute of technical thermodynamic Karlsruhe (ITTK). To realize an absorption-based system with a working pair using an IL instead of common used corrosive and toxic LiBr leads to a direct need of reliable Vapour-Liquid-Equilibria (VLE) measurements for the estimation of the performance. Thus, the partial pressure of a water-IL-mixture was determined by Fourier-Transform- Infrared (FT-IR) and Raman-Spectroscopy. In addition, important properties such as viscosity and specific heat capacity were measured as a function of concentration. A mixture of diethylmethylammonium methanesulfonate (DEMA MeSO3) and water was tested in 10 kW-apparatus and the COP was found to be comparable to the one of lithium bromide (LiBr) – water, although the higher viscosities of the used working solutions with RTILs still cause an insufficient heat and mass transfer, leading to an insufficient refrigeration output and to further optimization of the fluids.