Exploiting monoterpenoids in type V deep eutectic solvents: A combined high-pressure experiments and theoretical approach for enhanced carbon dioxide and nitrogen absorption

Abstract

This comprehensive study investigates the development, characterization, and application of natural hydrophobic deep eutectic solvents (HDES) in high-pressure gas capture, focusing specifically on carbon dioxide (CO2) and nitrogen (N2). Two binary HDES systems were formulated, using LnA as a hydrogen bond donor (HBD) and CAR and CIN as hydrogen bond acceptors (HBA). The HDES materials were thoroughly characterized, examining properties such as density, viscosity, conductivity, acidity, surface tension, and hydrophobicity across varying temperature ranges using state-of-the-art equipment. High-pressure gas solubility experiments were conducted to assess CO2 and N2 sorption capacities, demonstrating promising results. Simultaneously, an integrated computational approach was applied: COSMO-RS was used to predict solid–liquid equilibria (SLE) and the eutectic point of the NADES, while Density Functional Theory (DFT) calculations aided in optimizing molecular geometries and understanding the dispersion interactions. Furthermore, molecular dynamics (MD) simulations were employed to evaluate solubility of CO2 and N2 in the NADES and their interaction energies. The results from this dual experimental and computational approach show the potential of these HDES systems in high-pressure gas capture. This study represents a significant addition to the knowledge of deep eutectic solvents, their synthesis, characterization, predictive modeling, and practical applications.