Industrial carbon capture from diluted carbon sources based on ionic liquids: Material design and technological limit
Performing CO2 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 CO2 concentrations (measured by CO2 partial pressure PCO2) by proper anion change and...
| Autores: | , , , , |
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| Tipo de recurso: | artículo |
| Fecha de publicación: | 2026 |
| País: | España |
| Institución: | Universidad Autónoma de Madrid |
| Repositorio: | Biblos-e Archivo. Repositorio Institucional de la UAM |
| Idioma: | inglés |
| OAI Identifier: | oai:dnet:biblosearchi::c586f93bf34919bdc575f1825f9bdff9 |
| Acceso en línea: | https://hdl.handle.net/10486/775340 https://dx.doi.org/10.1016/j.seppur.2026.138689 |
| Access Level: | acceso abierto |
| Palabra clave: | Carbon capture Ionic liquids Economic assessment Process simulation COSMO/ASPEN Química |
| Sumario: | Performing CO2 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 CO2 concentrations (measured by CO2 partial pressure PCO2) 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 [P66614]+ cation. Afterwards, most of the designed AHA-ILs were taken into rigorous process simulation in Aspen Plus for CO2 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% CO2 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 PCO2. Additionally, at lower PCO2 industrial scenarios, the number of workable AHA-ILs is reduced. It was found that the minimum reachable PCO2 was around 0.01 bar with an estimated total annualized cost of 93 $/tCO2 for the best AHA-IL, with lower values for less extreme CO2 concentration conditions, sitting at 39 $/tCO2 for PCO2 of 0.13 bar. An explosive growth in the cost, and in the incorporated KPIs such as the CO2 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 [P2228]+ 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 CO2 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 |
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