ORALS

SESSION: MoltenMonPM1-R3	Fehrmann International Symposium on Sustainable Molten Salt and Ionic Liquid Processing (6th Intl. Symp. on Sustainable Molten Salt and Ionic Liquid Processing)
Mon Nov, 5 2018 / Room: Bossa (150/3rd)
Session Chairs: Peter Wasserscheid; Session Monitor: TBA

14:50: [MoltenMonPM107]
Switchable Aqueous Pentaethylenehexamine for CO₂ Capture
Santosh Khokarale¹ ; Jyri-pekka Mikkola² ; ¹Chemistry Department, Umeå University, Umeå, Sweden; ²Abo Akademi University, Turku, Finland;
Paper Id: 180 [Abstract]

Carbon dioxide (CO₂) concentration in the atmosphere surpassed the 400 ppm milestone in 2016 [1], approximately 120 ppm higher compared to the pre-industrial era. Along with the significant increase in the CO₂ level during the past decades, the human race has witnessed unprecedented climate change [2]. Therefore, it is necessary to find an efficient solution for capturing CO₂ from flue gases, in order to cut down anthropogenic CO₂ emissions. There is an increasing interest in polyamines, because they possess multiple reactive sites for high CO₂ uptake capacity, high thermal stability, as well as lower toxicity compared to the today's alternatives. Polyamines have the potential to improve the CO₂ loading, CO₂ absorption rate, and has a lower energy penalty [3, 4]. <br /> A reversible CO₂ uptake study was performed in neat pentaethylenehexamine (PEHA) and its aqueous solutions, and the performance was compared with industrially applied aqueous solution of monoethanolamine (MEA). Simultaneously, the relative amount of CO₂ chemisorbed chemical species, such as carbamates/(bi)-carbonates forming, was studied using NMR analysis and a calculation method introduced by Holmes et al. [5]. Furthermore, the CO₂ capture capacity of the solvents, correlated with their respective Kamlet-Taft polarity parameters, and the system were modelled with Linear Solvation Energy Relationship (LSER) approach. <br />It was observed that CO₂ capture capacity, as well as the nature of chemical species were influenced by water. The LSER calculations represented that amongst the studied Kamlet-Taft parameters, the CO₂ capture capacity merely depends on hydrogen bond acceptor ability (beta) and polarizability (pi). Upon the thermal regeneration study, the pure PEHA was obtained from CO₂ saturated reaction mixture at 120°C. Considering the high CO₂ absorption capacity and very low evaporation rate during regeneration compared to aqueous solution of MEA, PEHA can be used as a sustainable solvent for CO₂ capture in large-scale flue gas cleaning processes.

References:
[1] E. Dlugokencky, P. Tans, NOAA/ESRL (www.esrl.noaa.gov/gmd/ccgg/trends/).
[2] R. A. Kerr, Science 316 (2007), 188-190
[3] Y. E. Kim, S. J. Moon, Y. I. Yoon, S. K. Jeong, K. T. Park, S. T. Bae, S. C. Nam, Separation and Purification Technology 122 (2014) 112-118
[4] P. Muchan, J. Narku-Tetteh, C. Saiwan, R. Idem, T. Supap, Separation and Purification Technology 184 (2017) 128-134
[5] P. E. Holmes II, M. Naaz, B. E. Poling, Ind. Eng. Chem. Res. 37 (1998) 3281-3287