Prediction of Greenhouse Gas Solubility in Eutectic Solvents Using COSMO-RS

abstract

Over the past few years, eutectic solvents (ESs) have drawn the scientific community's attention because they are usually more environmentally friendly than traditional organic solvents. One of the applications of ESs is in the gas capture field, where they are considered promising absorbers to replace amine- (MEA, DEA, or MDEA processes), methanol- (Rectisol process), dimethyl ethers of polyethylene glycol- (Selexol process), N-methyl-2-pyrrolidone- (Purisol process), propylene carbonate- (Fluor solvent process), or morpholine-based (Morphysorb process) solvents on CO2 capture from the atmosphere. Although several studies have reported experimental gas solubility data in ESs, especially for CO2, only a few existing options are covered. In fact, resorting to experimental methods to obtain the solubility data seems unfeasible considering the vast number of possible eutectic mixtures. Therewith, theoretical predictions of gas solubility in ESs are valuable for the fast pre-screening of prospective solvents. In this work, the ability of the thermodynamic model COSMO-RS to represent solubility data of CO2, CH4, and H2S in 17 choline chloride-based (ChCl) ESs was evaluated. The experimental data were collected from the literature at different molar ratios, at 298.15 K or 313.15 K, and in the pressure range from 1 to 125 bar. COSMO-RS offers a qualitative description of these gases' solubility, which was expected due to the model's fully predictive character. To improve the CO2 and CH4 solubility data description, a temperature-pressure-dependent correction was applied to the COSMO-RS predictions for these gases, offering a global average relative deviation of 15%.

keywords

CARBON-DIOXIDE; CHOLINE-CHLORIDE; IONIC LIQUIDS; CO2 CAPTURE; FURFURYL ALCOHOL; SCREENING MODEL; SO2 ABSORPTION; LEVULINIC ACID; REAL SOLVENTS; EFFICIENT

subject category

Thermodynamics; Chemistry; Mechanics; Physics

authors

Pelaquim, FP; Vilas-Boas, SM; do Nascimento, DC; Carvalho, PJ; Neto, AMB; da Costa, MC

Groups

G4 - Renewable Materials and Circular Economy

Projects

Nano-argilas para remoção/captura de fosfatos (P) e sua reutilização como fertilizante (NATURAL)

CICECO - Aveiro Institute of Materials (UIDB/50011/2020)

CICECO - Aveiro Institute of Materials (UIDP/50011/2020)

Associated Laboratory CICECO-Aveiro Institute of Materials (LA/P/0006/2020)

acknowledgements

The authors thank the Sao Paulo Research Foundation (FAPESP-2018/19198-9 and 2014/21252-0), Coordination for the Improvement of Higher Education Personnel-Brasil (CAPES)-Finance Code 001, the National Council for Scientific and Technological Development (CNPq-312848/2023-4), and the Fund for the Support of Education, Research and Extension (FAEPEX/UNICAMP) for the financial support. The authors also thank the Human Resources Program of the National Agency of Petroleum, Natural Gas and Biofuels (PRH-ANP). This work was developed within the scope of the project CICECO Aveiro Institute of Materials, UIDB/50011/2020, UIDP/50011/2020 & LA/P/0006/2020, financed by national funds through the FCT/MEC (PIDDAC).