H2S-CO2 gas separation with ionic liquids on low ratio of H2S/CO2

Tri Partono Adhi; Yohanes Andre Situmorang; Haryo Pandu Winoto; Danu Ariono; Diannisa Septiana; Patricia Imanuela; Antonius Indarto

doi:10.1016/j.heliyon.2021.e08611

H₂S-CO₂ gas separation with ionic liquids on low ratio of H₂S/CO₂

Heliyon. 2021 Dec 15;7(12):e08611. doi: 10.1016/j.heliyon.2021.e08611. eCollection 2021 Dec.

Authors

Tri Partono Adhi¹, Yohanes Andre Situmorang², Haryo Pandu Winoto¹, Danu Ariono¹, Diannisa Septiana¹, Patricia Imanuela¹, Antonius Indarto^{1

2}

Affiliations

¹ Department of Chemical Engineering, Institut Teknologi Bandung, Labtek X, Kampus ITB, Jalan Ganesha 10, Bandung, 40132, Indonesia.
² Department of Bioenergy Engineering and Chemurgy, Institut Teknologi Bandung, Jalan Let. Jen. Purn. Dr. (HC), Mashudi No. 1, Sumedang, Indonesia.

Abstract

Acid gas removal, especially H₂S and CO₂, is an essential process in natural gas processing. In this research, 1-butyl-3-methylimidazolium bromide [bmim][Br] ionic liquid was analyzed as a hydrophobic solvent with has high selectivity to H₂S as an environmentally friendly solvent to absorb acid gas from natural gas with low H₂S/CO₂ concentration in ambient temperature and pressure. The absorption performance of pure [bmim][Br] ionic liquid was compared with various amine solutions, such as monoethanolamine (MEA), triethanolamine (TEA), and methyldiethanolamine (MDEA), as well as the mixture of [bmim][Br]-MDEA with various concentration. As a result, pure [bmim][Br] ionic liquid had high selectivity to H₂S compared with conventional amine solutions. In addition, the mixture of [bmim][Br]-MDEA with the mass ratio of 1:3 provided the highest H₂S/CO₂ selectivity of 6.2 in certain absorption conditions due to free tertiary amine attached in the cations of ionic liquids that can attract more H₂S to its functional site.

Keywords: Carbon dioxide; Hydrogen sulfide; Ionic liquids; Selective separation; [bmim][Br].