Co2 Capture Using Deep Eutectic Solvents

Speaker #1 Nouman Mirza

Department(s): Chemical and Biomolecular Engineering,Peter Cook Centre

Supervisor(s): Prof. Geoff Stevens

Topic: Co2 Capture Using Deep Eutectic Solvents

Abstract:

Carbon capture is one of technologies which can help reduce the global warming. Absorption of CO2 in a liquid solvent is the one of the preferred ways to reduce the amount of CO2 in the atmosphere. In the present work, an in-depth literature review has been undertaken on deep eutectic solvents (DESs), especially regarding their potential application as CO2 capture solvents. In order for these solvents to be used as CO2 capture media, knowledge of their critical properties needs to be established. To do so, modified Lydersen-Joback-Reid (LJR) method was combined with Lee Kesler’s mixing rules to estimate the critical temperature, critical pressure, critical volume, acentric factors, and normal
boiling points of 39 different DESs. An independent density-based method was used to determine the accuracy of the method. Based upon the estimated critical properties, densities of these 39 DESs were estimated and compared with the experimental values. The results showed that absolute deviations ranged from 0% to 17.4%. For DESs consisting of aliphatic precursors, the deviations ranged from 0% to 9.5%, whereas for DESs consisting of at least one aromatic precursor, the deviations ranged from 5.8% to 17.4%. The accuracy of method decreased with an increase in the content of hydrogen-bond donors (HBD) in a DES. The method was also found to accurately take into account the variation of density with temperature change. After the discovery of DESs, most of the researchers focused only on choline chloride based DESs, even for carbon capture applications. Due to this, a number of different physico-chemical properties of these solvents were published in the literature. Considering the fact, three choline chloride-based DESs, namely reline, ethaline and malinine were chosen to study the CO2 absorption capacity at conditions prevalent in a post-combustion capture process. Additionally, thermodynamic modelling using a modified Peng-Robinson (PR) equation of sate was used to correlate the experimental data. Finally, efforts were made to improve the already studied DESs for CO2 capture capacity.