RT Journal Article
T1 Tetrabutylphosphonium acetate and its eutectic mixtures with common-cation halides as solvents for carbon dioxide capture
A1 Pena, Carlos A.
A1 Soto Campos, Ana María
A1 Rodríguez Martínez, Héctor
K1 Ionic liquid
K1 CO2
K1 Absorption
K1 Tetraalkylphosphonium
K1 Eutectic
AB The absorption and desorption isotherms of CO2 in the ionic liquid tetrabutylphosphonium acetate ([P4 4 4 4][OAc]) were experimentally determined at 343.2 K in the pressure range 0–15 bar. Analysed in a mass basis, the CO2 absorption capacity of [P4 4 4 4][OAc] is particularly competitive among that of phosphonium ionic liquids. A contribution of chemical absorption was evidenced from the shape of the isotherms, and a reaction scheme based on the abstraction of an acidic proton in the cation by the basic acetate anion, with a 1:2 (CO2 to ionic liquid) overall stoichiometry, was proposed. The investigation of the solid–liquid equilibria of the mixtures of [P4 4 4 4][OAc] with its homologous halides, namely [P4 4 4 4]Cl and [P4 4 4 4]Br, led to the identification of eutectic behaviours, with the eutectic compositions having melting temperatures below 308.2 K, remarkably lower than the melting temperature of pure [P4 4 4 4][OAc]. The CO2 absorption capacities of these eutectic compositions were then explored at 308.2 K, and also 343.2 K for comparative purposes. While advantageously allowing their utilisation as CO2-capturing solvents at lower temperatures, in comparison to pure [P4 4 4 4][OAc] the eutectic mixtures did not lead to a major loss in CO2 absorption capacity, with greater physisorption compensating for the reduction in chemisorption.
PB Elsevier
YR 2020
FD 2020-12
LK https://hdl.handle.net/10347/44257
UL https://hdl.handle.net/10347/44257
LA eng
NO Pena, C., Soto, A., & Rodríguez, H. (2021). Tetrabutylphosphonium acetate and its eutectic mixtures with common-cation halides as solvents for carbon dioxide capture. Chemical Engineering Journal, 409, 128191. https://doi.org/10.1016/j.cej.2020.128191
NO This work was supported by Xunta de Galicia through grant numbers ED431B 2017/023, ED431D 2017/06 (Galician Network of Ionic Liquids), and ED431E 2018/01 (CRETUS Strategic Partnership), co-funded by the European Regional Development Fund. The authors are grateful to Ms. Mar Orge and Ms. Mónica Dosil for support in the operation of some analytical equipment. The use of RIAIDT-USC analytical facilities is also acknowledged.
DS Minerva
RD 23 abr 2026