Solubility of Carbon Dioxide in Deep Eutectic Solvents Based on 3-Amino-1-Propanol and Tetraalkylammonium Salts at Low Pressure

Abstract

Deep eutectic solvents (DESs) became an object of a great interest as an alternative to ionic liquids (ILs) and commonly used in CO2 capture amine solutions. In the present study, five different DESs based on 3-amino-1-propanol as physical-chemical CO2 absorbents were used. The composition was chosen in order to estimate the effects of hydrogen bond acceptor:hydrogen bond donor (HBA:HBD) molar ratio, anion type and length of alkyl chain of composing salt. The Fourier Transform Infrared (FTIR) spectroscopy was used to confirm chemical reaction. The solubility of CO2 was measured at low pressures up to 170 kPa at the temperature range of 293–318 K. Viscosity, polarity and Kamlet–Taft parameters were determined in order to estimate the dependences of the parameters and the CO2 capacity. CO2 uptake was observed to improve with decreasing molar ratio of hydrogen bond donor. Comparing the CO2 capacity of [TBAC]-based DESs, at the approximate pressure of 50 kPa, it was observed that the capacity increased in the following order of molar ratios—1:8 < 1:6 < 1:4 and a decrease in molar ratio from 1:8 to 1:4 resulted in about a 100% increase of capacity. Compared to [TBAC][AP] DESs, the [TEAC][AP] 1:4 and [TBAB][AP] 1:4 exhibited higher CO2 uptake, though the best results were obtained for [TBAB][AP].

Reviewing and screening ionic liquids and deep eutectic solvents for effective CO2 capture

“…Nine studies have been focused on chemical-based DESs since 2021, as summarized in Table 4 . Among them, three DESs are newly synthesized ( Fu et al, 2021a ; Ahmad et al, 2021 ; Qian et al, 2022 ), while others are the previously synthesized ones for various purposes, including the discussion about the water content ( Liu et al, 2022 ) and estimating the effects of HBA:HBD molar ration, type of anion, and the alkyl chain ( Cichowska-Kopczyńska et al, 2021 ).…”

“…Nine studies have been focused on chemical-based DESs since 2021, as summarized in Table 4. Among them, three DESs are newly synthesized (Fu et al, 2021a;Ahmad et al, 2021;Qian et al, 2022), while others are the previously synthesized ones for various purposes, including the discussion about the water content (Liu et al, 2022) and estimating the effects of HBA:HBD molar ration, type of anion, and the alkyl chain (Cichowska-Kopczyńska et al, 2021). Ahmad et al (2021) synthesized the MDEA-based DESs using [DEAHCl], [MDEAHCl], and [MEAHCl] as HBA and [MDEA] as HBD at 1:3 M ratio, and the CO 2 solubility (mol/kg) 2022) synthesized three-component ones using amino acids as HBA, amines as HBDs, and 10-30 wt% of ethylene glycol.…”

CO2 Separation Using Supported Deep Eutectic Liquid Membranes Based on 1,2-propanediol

“…However, due to the high price, complex synthesis, and low biodegradability of ILs, their alternatives are still being sought. Most recently, deep eutectic solvents (DESs) have been used in SLM as a new substitute to ionic liquids − and their CO 2 capacity was proven . DES-based SLMs have also become the subject of research in the field of olefin/paraffin separation, biotechnology, extraction, water purification, and energy processing and storage. − …”

Mathematical Modeling of the Solubility of Carbon Dioxide in Deep Eutectic Solvents

“…They can also be readily tailored for a particular purpose and then can take a variety of substances, including CO2. [11,12] Large-scale applications of ILs also are difficult to implement, and among the challenges is their massive cost. [13] Deep Eutectic Solvents (DESs) have begun to grow in prominence among scientists for a variety of uses, particularly in CO2 absorption.…”