Chemoinformatics-Driven Design of New Physical Solvents for Selective CO₂ Absorption

Abstract

The removal of CO 2 from gases is an important industrial process in the transition to a lowcarbon economy. The use of selective physical (co-)solvents is especially perspective in cases when the amount of CO 2 is large as it enables one to lower the energy requirements for solvent regeneration. However, only a few physical solvents have found industrial application and the design of new ones can pave the way to more efficient gas treatment techniques. Experimental screening of gas solubility is a labor-intensive process, and solubility modeling is a viable strategy to reduce the number of solvents subject to experimental measurements. In this paper, a chemoinformatics-based modeling workflow was applied to build a predictive model for the solubility of CO 2 and four other industrially important gases (CO, CH 4 , H 2 , N 2 ). A dataset containing solubilities of gases in 280 solvents was collected from literature sources and supplemented with the new data for six solvents measured in the present study. A modeling workflow based on the usage of several state-of-the-art machine learning algorithms was applied to establish quantitative structure-solubility relationships. The best models were used to perform virtual screening of the industrially produced chemicals. It enabled the identification of compounds with high predicted CO 2 solubility and selectivity towards the other gases. The prediction for one of the compounds − 4-Methylmorpholine was confirmed experimentally. SYNOPSIS STATEMENTDeveloping better solvents for selective CO 2 capture is crucial for reaching net-zero emissions targets.4

Preventing Aerosol Emissions in a CO2 Capture System: Combining Aerosol Formation Inhibition and Wet Electrostatic Precipitation

“…Carbon dioxide, as the major anthropogenic GHG, accounted for 72% of the total emissions in 2019 . Carbon capture, utilization, and storage has been considered a promising and necessary technology for reducing CO 2 emissions and contributing to achieving carbon neutrality. , Recently, amine scrubbing has become a promising large-scale CO 2 capture technology due to its high capture efficiency, mature process, and good compatibility. , However, some solvents and their degradation products are discharged with the flue gas while the CO 2 capture system operates . These emissions lead to solvent loss and a series of environmental problems…”

Reducing Aerosol Emissions by Decoupled Parameter Management during the CO2 Capture Process in a Multi-stage Circulation Absorber

“…Solvent emissions in the form of vapor and aerosols are one of the challenges in realizing a full-scale absorption–desorption-based post-combustion CO 2 capture (PCCC) plant. − Currently, amine-based solvents, such as monoethanolamine (MEA) solution, have been demonstrated at various pilot scales, culminating in commercial-scale deployment. , However, due to their inherent volatility, solvents will be entrained in the exhaust gas, leading to solvent volatility losses up to 0.8 kg/t CO 2 and atmospheric pollution, which raises great concerns about techno-economic and environmental safety…”

“…1−4 Currently, amine-based solvents, such as monoethanolamine (MEA) solution, have been demonstrated at various pilot scales, culminating in commercial-scale deployment. 5,6 However, due to their inherent volatility, solvents will be entrained in the exhaust gas, leading to solvent volatility losses up to 0.8 kg/t CO 2 7 and atmospheric pollution, which raises great concerns about techno-economic and environmental safety. 8 Recently, aerosol-based emissions have been reported from typical PCCC plants.…”

Selective H2S Absorption in Aqueous Tertiary Alkanolamine Solvents: Experimental Measurements and Quantitative Kinetic Model

“…Physical solvents can be used for bulk selective H 2 S removal. Many molecules can be used, ,, and common examples are the Rectisol, Purisol, and Selexol processes. The selectivity is thermodynamic …”