Thermophysical properties of aqueous amines solutions for CO2 capture applications
The climate change, driven by anthropogenic greenhouse gas (GHG) emissions such as CO2 and methane, demands urgent solutions. Carbon capture, utilisation, and storage (CCUS), alongside renewable energies and energy efficiency, are crucial alternatives. Chemical absorption using amines is currently t...
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| Tipo de recurso: | tesis doctoral |
| Estado: | Versión publicada |
| Fecha de publicación: | 2025 |
| País: | España |
| Institución: | Universidad de Valladolid |
| Repositorio: | UVaDOC. Repositorio Documental de la Universidad de Valladolid |
| OAI Identifier: | oai:uvadoc.uva.es:10324/79436 |
| Acceso en línea: | https://doi.org/10.35376/10324/79436 https://uvadoc.uva.es/handle/10324/79436 |
| Access Level: | acceso abierto |
| Palabra clave: | Termoquímica Thermophysical Properties Propiedades Termofísicas Amines Aminas CO2 Capture Captura de CO2 23 Química |
| Sumario: | The climate change, driven by anthropogenic greenhouse gas (GHG) emissions such as CO2 and methane, demands urgent solutions. Carbon capture, utilisation, and storage (CCUS), alongside renewable energies and energy efficiency, are crucial alternatives. Chemical absorption using amines is currently the most mature CO2 capture technology, although it presents challenges in efficiency, energy demand, and solvent stability. Currently, researchers in this field are focusing on optimising this process by searching for amines or amine blends that improve CO2 separation and allow for solvent regeneration at high temperatures with good stability. While monoethanolamine (MEA) is the most widely used solvent due to its rapid reactivity, other amines (tertiary, cyclic, sterically hindered) show potential for greater CO2 removal and lower energy consumption, albeit with challenges in reaction rate or solubility. To address these limitations, this PhD thesis investigates the combination of different types of amines. However, the thermophysical characterisation of these mixtures (density, viscosity, isobaric heat capacity) is fundamental to optimising the capture process. In this sense, this PhD thesis presents a comprehensive study of the volumetric, energetic, and transport properties of binary (amine + H2O), ternary (amine + H2O + CO2), and quaternary (amine + amine + H2O + CO2) mixtures involving various amines (MEA, DEA, EAE, MDEA, DMEA, DEAE, AMP, MAPA, 1-MPZ, PZ) across a wide range of temperature, pressure, and concentration conditions. The present work details the safe handling of amines, the precise preparation of mixtures, and CO2 loading. The equipment used to measure density (vibrating tube densimeter), isobaric heat capacity (flow calorimeter), and viscosity (Ubbelohde capillary viscometer) are meticulously described, including their operating principles, calibration procedures, and uncertainty analyses. The experimental results for density, isobaric heat capacity, and viscosity for the different systems studied are presented and discussed in detail. Different trends were observed as a function of temperature, pressure, and amine and CO2 concentration. The data obtained were compared with existing literature, generally showing good agreement. Correlation models (modified Tammann-Tait equation, empirical equations, Vogel-Fulcher-Tammann model) were developed and validated to describe the behaviour of these thermophysical properties. In conclusion, this research provides a valuable set of precise experimental data and robust correlation models for the thermodynamic properties of amine-based CO2 absorbents. These results significantly contribute to the fundamental knowledge necessary for the development of more efficient and sustainable CO2 capture technologies, crucial for mitigating the climate change. |
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