Enhancement of CO2 Adsorption/Desorption Properties of Solid Sorbents Using Tetraethylenepentamine/Diethanolamine Blends

Duc Sy Dao; Hidetaka Yamada; Katsunori Yogo

doi:10.1021/acsomega.0c01515

Enhancement of CO₂ Adsorption/Desorption Properties of Solid Sorbents Using Tetraethylenepentamine/Diethanolamine Blends

ACS Omega. 2020 Sep 4;5(37):23533-23541. doi: 10.1021/acsomega.0c01515. eCollection 2020 Sep 22.

Authors

Duc Sy Dao^{1

2}, Hidetaka Yamada^{2

3}, Katsunori Yogo^{2

3}

Affiliations

¹ Faculty of Chemistry, VNU University of Science, Vietnam National University, Hanoi (VNU-Hanoi), 19 Le Thanh Tong, Hoan Kiem, Hanoi 10000, Vietnam.
² Division of Materials Science, Nara Institute of Science and Technology (NAIST), 8916-5 Takayama-cho, Ikoma, Nara 630-0192, Japan.
³ Research Institute of Innovative Technology for the Earth (RITE), 9-2 Kizugawadai, Kizugawa, Kyoto 619-0292, Japan.

Abstract

Mesocellular silica foam was impregnated with tetraethylenepentamine (TEPA), diethanolamine (DEA), and their mixtures and examined as sorbents for CO₂ capture. The sorbents were characterized by N₂ physisorption, elemental analysis, and Fourier transform infrared spectroscopy. The effects of amine blending on the CO₂ uptake, working capacity, and heat of adsorption were investigated and discussed. The experimental results showed that the heat of adsorption decreased with increasing DEA-to-TEPA ratios, but the CO₂ uptake improved by the blending of TEPA and DEA. Furthermore, the DEA/TEPA blend considerably improved the regeneration properties of the sorbents. Mesocellular silica foam loaded with a mixture of 40 wt % TEPA and 30 wt % DEA exhibited a CO₂ adsorption uptake of 5.91 mmol/g at 50 °C and 100 kPa with a heat of adsorption of 80 kJ/mol. Additionally, these sorbents demonstrated high cyclic stability and high selectivity toward CO₂/N₂ separation. In situ infrared spectroscopy investigations revealed that CO₂ adsorption occurred predominantly through the formation of carbamate species for both TEPA and DEA.