Supported liquid membranes comprising of choline chloride based deep eutectic solvents for CO2 capture: Influence of organic acids as hydrogen bond donor.

[Display omitted] • Preparation of highly selective Choline Chloride based Deep Eutectic Solvent. • High CO 2 permeability for a supported DES based liquid membrane. • Supported liquid membranes showed excellent stability under different operating conditions. This study focuses on a forward looking approach in which deep eutectic solvents (DESs), a new class of designer solvents, were impregnated into micro porous polyvinylidene fluoride (PVDF) membrane for the separation of CO 2 from CH 4. Three types of DESs were prepared by mixing and heating of hydrogen bond acceptor (choline chloride) with either malic acid, tartaric acid or oxalic acid as hydrogen bond donor. The Fourier transform infrared spectroscopy confirmed the hydrogen bond interactions in the resulting DES. Thermal gravimetric analysis (TGA) was used to evaluate the thermal stability of the prepared membranes. The DES based supported liquid membranes were investigated systematically to determine the permeability and selectivity for the mixture of gases at both ambient and elevated temperatures. The results showed that Choline Chloride-Malic acid, Choline Chloride-Tartaric acid and Choline Chloride-Oxalic acid DES-SLMs exhibited CO 2 permeability of 30.32 Barrer, 34.00 Barrer and 37.30 Barrer, respectively while ideal selectivity of these membranes was found 51.39, 55.74 and 60.16 for CO 2 /CH 4 , respectively. The fabricated membranes were compared with some of the imidazolium supported ionic liquid membranes (SILMs) on the Robeson upper bound plot. The current study on DES-SLMs is expected to open new pathways for the exploitation of DESs for CO 2 capture. [ABSTRACT FROM AUTHOR]