Polyethylene glycol-based deep eutectic solvents as a novel agent for natural gas sweetening

Abstract

Deep eutectic solvents (DESs) have received significant attention as potential extracting agents in recent years due to their favorable characteristics including low cost, easy preparation and environmentally safe starting materials. Experimentally screening for highly efficient DESs meeting various requirements for natural gas sweetening remains a challenging task. Thus, an extensive database of estimated Henry's law constants (H i) and solubilities (x i) of CO 2 in 170 different DESs at 25˚C has been constructed using the COSMO-RS method to select potential DESs. Based on the COSMO-RS study, three DESs, namely tetrabutylammonium bromide (TBAB)+polyethylene glycol (PEG-8) (on a molar basis 1:4), TBAB+octanoic acid (OCT) (1:4), and methyltriphenylphosphonium bromide (MTPB)+PEG-8 (1:10), were chosen for further experimentation up to 2 bar at 25˚C using a vapor-liquid equilibria (VLE) apparatus. Reliable thermophysical properties were determined experimentally, and a detailed equilibrium-based model was developed for one of the glycol-based DESs (i.e., TBAB+PEG-8 (1:4)). This information is an essential prerequisite for carrying out process simulations of natural gas sweetening plants using ASPEN PLUS. The simulation results for the proposed DES were compared to those of monoethylene glycol (MEG). Here, we find that the aqueous TBAB+PEG-8 (1:4) solvent shows~60% lower total energy consumption and higher CO 2 removal when compared to those using the MEG solvent.

Multiscale Conceptual Design of a Scalable and Sustainable Process to Dissolve and Regenerate Keratin from Chicken Feathers

“…Using the COSMO-RS methodology to estimate the thermodynamic properties of the DES and its mixtures forces us to define how to model this component. The two alternatives more frequently considered in the literature – with this purpose were explored here: (i) representing the (NaAc + urea) DES as a mixture of the individual components (in the current case 1NaAc and 2urea molecules) or (ii) considering the DES is the molecular aggregate shown in Figure .…”

“…Conductor-like screening model for real solvents (COSMO-RS) methodology and quantitative structure–property relationship (QSPR) models based on its descriptors (as implemented in the COSMOtherm program package) were used to predict the thermodynamic, volumetric, and transport properties of the individual components and their mixtures. COSMO-based methodologies have been extensively used in determining the properties of IL, DESs, and their mixtures with conventional organic compounds. – The calculated properties received three main uses in this work: (i) characterizing the electronic structure of the components involved in the process. In particular, the density of the polarized charge distribution on the molecular surface was considered, which was reported in the form of the corresponding σ-profile; (ii) studying the interactions among the components in a mixture.…”

Deep eutectic solvents as a versatile platform toward CO2 capture and utilization

“…5 and 10 wt% during the preparation of amine-based DESs, can not only significantly decrease the viscosity of the resulting DESs but also maintain high CO 2 absorption capacity and high thermal stability. 111 Water has also been found to slow down CO 2 uptake in amine-based DESs due to the influence on intermolecular interactions. 22 CO 2 adsorption on 20 μm TEPA film clarifies that CO 2 and H 2 O are preferentially adsorbed on primary and secondary amine sites, respectively, and thus the presence of water promotes the formation of carbamic acid.…”

Modeling Carbon Dioxide Absorption in Choline Chloride Based Deep Eutectic Solvents Using COSMO-SAC Method

“…The COSMO-SAC model can compare CO₂ solubility in different DESs and find the highest capacity absorbent. Aldawsari et al [25] employed the COSMO-RS approach to create a database of CO₂ solubility in 170 DESs and to screen for promising DESs. Luo et al [26] similarly screened CO₂ solubility in 280 DESs using the COSMO-SAC model.…”