Publicação
Evaluation of ionic liquid mixtures as an alternative for CO₂ capture
| Resumo: | The emission of greenhouse gases into the atmosphere, in particular carbon dioxide (CO2), has become problematic due to climate change. To combat this problem, many researchers have focused their activities on the development of new processes and methodologies to mitigate greenhouse gases. Among the alternatives, carbon capture and storage technologies play a key role in mitigating CO2. Within the range of solvents proposed as innovative and with a high potential for CO2 capture, ionic liquids (ILs) offer unique properties, being a promising alternative in the replacement of critical solvents commonly used in the physical sorption of this gas. Although the potential of ILs is evident in CO2 capture, the application of these solvents to industrial-scale processes is still at a very early stage. This is partly due to the little knowledge of thermophysical properties of ILs, such as density and solubility, that limit the development of robust models essential in the development of processes. Thus, in this thesis, ILs based on carboxylates are evaluated as potential solvents for CO2 capture. To study the viability of this alternative, liquid-vapor equilibrium data are necessary. In addition, the description of thermophysical properties by equations of state (EoS) are essential for the design of industrial process. The solubility data - pVT diagram - were obtained using an isochoric cell, in the range of temperatures and pressures from 298 to 363 K and 0.1 to 95 MPa. The density data were measured using a high-pressure measuring cell - diagram ρpT - in the temperature and pressure range from 298 to 363 K and 0.1 to 95 MPa. These were modeled using EoS based on statistical mechanics, Tait Equation. The ILs analyzed in this work show a high capacity for the physical absorption of CO2. The density and derived properties, namely isothermal compressibility and isobaric thermal expansion, modeled using PC-SAFT EoS. The EoS using Tait Equation and PC-SAFT demonstrated difficulty in describing the experimental data, with the association volume parameter very close to zero, which has no physical significance, since the compounds have functional groups that interact with each other. PC-SAFT provides a better description of the experimental data, with parameters with valid physical meaning. According to the results obtained in this work, further studies of thermophysical characterization and pure parameters of ionic liquids used in mixture are necessary to create a solid database that allows its application at an industrial level. |
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| Autores principais: | Velandia Manosalva, Jairo Alexei |
| Assunto: | Ionic liquid mixtures Carbon dioxide Density Miscibility Modelling of binary system |
| Ano: | 2024 |
| País: | Portugal |
| Tipo de documento: | dissertação de mestrado |
| Tipo de acesso: | acesso aberto |
| Instituição associada: | Universidade de Aveiro |
| Idioma: | inglês |
| Origem: | RIA - Repositório Institucional da Universidade de Aveiro |
| Resumo: | The emission of greenhouse gases into the atmosphere, in particular carbon dioxide (CO2), has become problematic due to climate change. To combat this problem, many researchers have focused their activities on the development of new processes and methodologies to mitigate greenhouse gases. Among the alternatives, carbon capture and storage technologies play a key role in mitigating CO2. Within the range of solvents proposed as innovative and with a high potential for CO2 capture, ionic liquids (ILs) offer unique properties, being a promising alternative in the replacement of critical solvents commonly used in the physical sorption of this gas. Although the potential of ILs is evident in CO2 capture, the application of these solvents to industrial-scale processes is still at a very early stage. This is partly due to the little knowledge of thermophysical properties of ILs, such as density and solubility, that limit the development of robust models essential in the development of processes. Thus, in this thesis, ILs based on carboxylates are evaluated as potential solvents for CO2 capture. To study the viability of this alternative, liquid-vapor equilibrium data are necessary. In addition, the description of thermophysical properties by equations of state (EoS) are essential for the design of industrial process. The solubility data - pVT diagram - were obtained using an isochoric cell, in the range of temperatures and pressures from 298 to 363 K and 0.1 to 95 MPa. The density data were measured using a high-pressure measuring cell - diagram ρpT - in the temperature and pressure range from 298 to 363 K and 0.1 to 95 MPa. These were modeled using EoS based on statistical mechanics, Tait Equation. The ILs analyzed in this work show a high capacity for the physical absorption of CO2. The density and derived properties, namely isothermal compressibility and isobaric thermal expansion, modeled using PC-SAFT EoS. The EoS using Tait Equation and PC-SAFT demonstrated difficulty in describing the experimental data, with the association volume parameter very close to zero, which has no physical significance, since the compounds have functional groups that interact with each other. PC-SAFT provides a better description of the experimental data, with parameters with valid physical meaning. According to the results obtained in this work, further studies of thermophysical characterization and pure parameters of ionic liquids used in mixture are necessary to create a solid database that allows its application at an industrial level. |
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