Intermolecular interactions within the mixtures of DMSO and reline, a typical type III Deep Eutectic Solvent (DES), composed of urea and choline chloride, is examined along with the mixtures' physical properties.

The recent socio-political and climate changes have sparked tremendous interest in developing effective CO2 capture processes. Conventional post-combustion CO2 capture (PCCC) processes employ aqueous monoethanolamine (MEA) as a solvent; however, one of the major problems in the PCCC columns is the loss of a significant amount of the solvent in the form of particulate matter (PM). In spite of its importance, the formation of PM in a PCCC column has been overlooked, until recently. We herein analyze the process of the PM formation at a molecular level by underlining interactions between the participating components. Molecular dynamics (MD) simulations were performed on different systems consisting of CO2 and MEA, and also in the presence of other components and conditions that are typically present in a PCCC column. The simulation revealed the evolution of molecular clusters, which are in a separate phase than the gas present around, comprising all the gaseous MEA, SO2, and most of the CO2 and water vapor. We found the nucleation rate of the formed PM to be in the order of 1030 cm–3 s–1 for the studied systems. The presence of water vapor enhanced the growth of the clusters, although the structure remained largely unchanged. On the other hand, although SO2 was all absorbed in the cluster, it did not alter the growth rate or the structure of the formed cluster. Interestingly, the results also showed formation of large molecular clusters even at a low degree of supersaturation because of strong CO2–water interactions. Taken together, the results are the first of the efforts to understand PM formation in a typical PCCC column based on molecular simulations, and the findings led to certain practical suggestions to reduce PM formation.

Ethanolamines have traditionally been used for capturing CO 2 in a postcombustion carbon capture column. However, the use of ethanolamines, due to their high volatility and solvent losses, is not sustainable. One of the ways in which the solvent loss occurs is in the form of aerosols from the top of the column. The mechanism, rate of nucleation, growth rate, and interaction leading to the formation of aerosols, although essential for better process design, remain obscure. Using molecular dynamics simulations, we herein, analyze the formation of aerosols in columns based on aqueous monoethanolamine (MEA), aqueous methyldiethanolamine (MDEA), and their mixtures, using reference, pilot-scale, and industrial-scale data. In particular, the nucleation rate and cluster growth analyses were performed for five different cases. The results show that CO 2 concentration had a strong influence on the rate of aerosol formation, a factor that can be easily controlled for better process design. Moreover, the interactions within the formed aerosols were mainly dominated by CO 2 −water interactions. Taken together, our results and analysis contribute toward a better understanding of aerosol formation and present some practical value, namely, calculated nucleation rates and particulate growth rates can be used in process simulators to account for solvent losses, factors that were identified as contributing to formation of particulate matter can be controlled and adjusted in design process simulations and in real plants, providing better performance of postcombustion carbon capture columns and thus suggest ways to prevent solvent loss.