Predicting the CO₂ Capture Capability of Deep Eutectic Solvents and Screening over 1000 of their Combinations Using Machine Learning

Abstract

Deep eutectic solvents (DESs) are a new class of environmentally friendly solvents that have attracted the attention of many researchers. Since DESs have several practical applications in CO 2 capture, knowledge of their CO 2 solubility is crucial. In this study, the CO 2 solubility of DESs was predicted via a multilayer perceptron (MLP) using molecular descriptors derived from the Conductor-like Screening Model for Real Solvents (COSMO-RS). An extensive database of 2327 data points was created from 94 unique DES mixtures made from 2 anions, 17 cations, and 39 hydrogen bond donors (HBDs) at 150 different compositions and operating conditions of temperatures and pressures. Several statistical tests were performed, and after thorough hyperparameter tuning, it was found that the best MLP architecture predicted the CO 2 solubility with an R 2 value of 0.986 ± 0.002 and an average absolute relative deviation (AARD) of 4.504 ± 0.507. The MLP has also been loaded into an accessible Excel spreadsheet included in the Supporting Information. Thereafter, in order to guide DES molecular design for achieving high CO 2 solubilities, the MLP was utilized for the high-throughput screening of 1320 DES combinations. This model encourages the creation of robust and accurate models to predict the CO 2 solubility of novel DESs, which will minimize the need for conducting costly and time-consuming experiments.

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

“…7d and e), respectively. Based on COSMO-RS-derived molecular descriptors, 125 an accurate nonlinear QSPR model has been developed using the random forest method, which provides reliable predictions of CO 2 solubility in DESs. 120…”

Transformer-Based Representation of Organic Molecules for Potential Modeling of Physicochemical Properties

“…Therefore, physical property prediction models become a powerful tool to preselect suitable fluids for chemical processes on which to focus in-depth research and allowing resources to be appropriately allocated. Recently, there have been numerous applications in this field such as design of ionic liquids, optimization of energy recovery, design of extraction solvents, design of chemical adsorbents, and design of solvents for carbon capture. , …”

Deep Eutectic Solvents Reduce the Life Cycle Environmental Impacts and Energy Demands of Carbon Dioxide Capture

“…12,14,15 DESs have exhibited superior CO 2 absorption/ desorption performance compared with conventional solvents 16−20 and have been favorably evaluated due to their high CO 2 absorption capacity, recyclability, tunable viscosity, and miscibility with a variety of solvents such as water, alkanolamines, and ionic liquids. 16,17,20,21 In addition, considerable reductions in energy demand have been reported when using a DES in a CO 2 capture system compared to alkanolamines. 22,23 Although energy efficiency is vital, it is insufficient to qualify a system as an environmentally friendly alternative due to the complex interplay among energy demand, material utilization, and environmental impacts.…”

“…The adverse environmental impacts and high energy demand of alkanolamine-based CO 2 capture systems can be mitigated by replacing conventional CO 2 absorbents with environmentally benign and energy-efficient alternatives. Deep eutectic solvents (DESs) are attractive candidates for this purpose due to their tunable properties, task specificity, low cost, negligible vapor pressure, nonflammability, simple synthesis, regenerability, and good biodegradability. ,, DESs have exhibited superior CO 2 absorption/desorption performance compared with conventional solvents − and have been favorably evaluated due to their high CO 2 absorption capacity, recyclability, tunable viscosity, and miscibility with a variety of solvents such as water, alkanolamines, and ionic liquids. ,,, In addition, considerable reductions in energy demand have been reported when using a DES in a CO 2 capture system compared to alkanolamines. , …”

“…Several studies have attempted to perform LCAs of postcombustion CO 2 capture from power plants. − However, most such studies were conducted on coal-fired power plants using conventional absorbents. ,,− As of January 2023, only 11 studies were indexed in the Web of Science database against the search terms “combined heat and power*″, “LCA”, and “carbon dioxide*″. Kelly et al .…”