Greener gas capture in deep eutectic solvents aqueous solutions: Performance in a dynamic condition. (10th December 2019)

• Record Type: Journal Article
• Authors: Carlesi, Carlos; Guajardo, Nadia; Schrebler, Rodrigo; Vasquez-Sandoval, Dreidy
• Is Part Of: Journal of cleaner production. Volume 240(2019)
• Publication Date: 2019-12-10
• Subjects: Ionic liquids -- Deep eutectic solvents -- Choline chloride -- Sulphur dioxide -- Gas absorption -- Packed bed column; Factory and trade waste -- Management -- Periodicals; Manufactures -- Environmental aspects -- Periodicals; Déchets industriels -- Gestion -- Périodiques; Usines -- Aspect de l'environnement -- Périodiques; 628.5
• DOI: 10.1016/j.jclepro.2019.118240
• Languages: English
• ISSNs: 0959-6526

Abstract

Abstract: The handling of large gas volumes containing low SO2 concentrations is still a challenge for the industry. Here is possible to identify an opportunity for a cleaner production by using novel solvents such as ionic liquids (ILs) specially biodegradables Deep Eutectic Solvents (DES) as an alternative of amine-based absorbents which are volatile and easily degrades and may produce further contamination and health hazard. The present work analyses the performance of four DESs were under dynamic conditions (in a packed-bed column) for SO2 absorption. The results were compared with the absorption capacities published for the same DESs under static conditions identifying essential differences to consider in a large-scale implementation. At low SO2 partial pressure (600 ppm), chemical absorption becomes the most important mechanism, and thus, the chemical nature of the DES determines the absorption capacity. DESs containing amine groups showed superior absorption, and between the thiourea- and urea-containing DESs, the former exhibited the best performance, which was not related to its viscosity nor its initial solution pH but rather to the chemical interaction of functional groups in the DES promoting ionic interaction with generated sulphites. Highlights: An aqueous Deep Eutectic Solvents (DES) solution allows intensifying SO2 absorption. Contact system influences the relative absorption capacities among different DES. At low SO2 partial pressure, chemical absorption is rate determining. Not viscosity nor initial pH are relevant to absorption capacity. The DES compressing amine groups have shown superior absorption capacity.