Probing the structural organization of a low temperature transition mixture for CO2 capture through spectroscopic and theoretical studies

We investigated a low temperature transition mixture (LTTM) suitable for carbon capture through infrared spectroscopy, differential scanning calorimetry, absorption of CO2 and computational studies. The system, made up of a homogeneous mixture of ethylene glycol, potassium hydroxide and boric acid (3:1:1), is sensitive to temperature changes that affect the viscosity of the solvent and its capacity to exchange CO2 at the interface. The relationship between the LTTM's molecular structure and its ability to capture the gas were investigated in order to optimize the properties of the absorbing material for developing viable and reusable carbon capture systems. The results suggest that a large number of free OH groups is available to ensure an effective CO2 capture through the formation of the organic carbonate, leading to an average absorption of 22 ± 1 gCOjavax.xml.bind.JAXBElement@7fcbc253/kgsolv at room temperature. Boric acid acts as a catalyst for the carbonate decomposition and ensures the release of CO2 at 60 °C. ATR-FTIR measurements proved that the solvent is mostly regenerated after desorption and can thus continue to absorb further CO2 over a large number of cycles, making the system reusable.