Industrial carbon capture from diluted carbon sources based on ionic liquids: Material design and technological limit

Unofficial AI-generated summary based on the public title and abstract. Not an official translation.

🔬研究者:Provides a comprehensive methodology for screening ionic liquids for carbon capture from diluted sources, including process simulation and cost analysis.

🏢実務担当者:Offers guidelines for selecting ionic liquids and optimizing process parameters for cost-effective carbon capture from low-concentration streams.

🏛政策担当者:Highlights the technical and economic feasibility limits of packed column technology for diluted CO2 capture, suggesting the need for alternative contactors for sub-0.01 bar conditions.

Performing CO 2 capture from diluted sources constitutes an important technical challenge. Aprotic Heterocyclic Anion-based Ionic Liquids (AHA-ILs) have been demonstrated to be suitable for a wide range of inlet gas CO 2 concentrations (measured by CO 2 partial pressure P CO2 ) by proper anion change and functionalization. To test their applicability at diluted concentrations, in this work, more than 200 AHA-ILs have been designed and tested by the DFT/COSMO and COSMO/ASPEN methodologies. This expansion of the chemical space more than doubles AHA-ILs availability for process scale simulation compared to previous studies and enables uptake prediction from the material properties (reaction equilibrium constant and physical solubility Henry constant) paired with [P 66614 ] + cation. Afterwards, most of the designed AHA-ILs were taken into rigorous process simulation in Aspen Plus for CO 2 concentrations starting from the reference post-combustion (0.13 bar), towards more diluted concentrations never studied in previous publications, and until reaching the operability limit in an absorption-regeneration packed columns process scheme with temperature and pressure swing absorption. Results show that insights gained from the theoretical cyclic capacity of the AHA-ILs can anticipate promising candidates at the process scale. Additionally, it was found that the reaction equilibrium constant, primarily defined by the enthalpy of reaction, is the main material property affecting cyclic capacity, which at the same time determines the Ionic Liquid flow requirements to achieve the 90% CO 2 removal from the inlet gas. The needed AHA-ILs flow requirement severely affects the main key process indicators (KPIs) of the process, which impact the variable operating costs and the equipment's installed costs, compromising the final techno-economic feasibility of using a certain AHA-IL at a specific P CO2 . Additionally, at lower P CO2 industrial scenarios, the number of workable AHA-ILs is reduced. It was found that the minimum reachable P CO2 was around 0.01 bar with an estimated total annualized cost of 93 $/t CO2 for the best AHA-IL, with lower values for less extreme CO 2 concentration conditions, sitting at 39 $/t CO2 for P CO2 of 0.13 bar. An explosive growth in the cost, and in the incorporated KPIs such as the CO 2 emissions associated with the utilities usage, and the columns flooding for pressures lower than 0.01 bar, even for the best possible AHA-ILs, make the packed columns process not viable, highlighting the necessity of a contactor technology replacement that would enable the exploitation of the full potential of the material. Finally, future optimization pathways such as cation change and energy integration have been minimally explored to evaluate potential improvements. It was found that by selecting [P 2228 ] + cation (significant reduction of molar weight) and by performing feed to effluent energy integration in the regeneration column, energy requirements could be reduced up to a 39% for the best found AHA-IL at post-combustion CO 2 concentration. This highlights the need for further experimental studies to develop isotherm models that incorporate the cation effect, along with the need of process optimization.

• openalex https://doi.org/10.1016/j.seppur.2026.138689first seen 2026-06-07 05:00:49