Examinando por Autor "Moya, Cristian"
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Publicación CO2 Capture by Supported Ionic Liquid Phase: Highlighting the Role of the Particle Size(2019-06-27) Lemus, Jesús; Hospital Benito, Daniel; Moya, Cristian; Bedia, Jorge; Alonso Morales, Noelia; Rodríguez Jiménez, Juan J.; Palomar Herrero, José Francisco; Santiago Lorenzo, RubénCO2 capture by fixed-bed sorption has been evaluated using Supported Ionic Liquid Phase (SILP) based on the ionic liquid 1-butyl-3-methylimidazolium acetate ([bmim][acetate]). The SILP sorbent was prepared with three remarkably different mean particle sizes and characterized by porous texture, morphology, thermal stability, and elemental composition. The thermodynamics and kinetics of the CO2 capture process has been studied, testing the effects of SILP particle size, sorption temperature, gas flow rate, and CO2 partial pressure. The CO2 sorption isotherms at different temperatures were obtained by gravimetric measurements, revealing that the equilibrium sorption capacity is only due to the IL incorporated on the silica support of SILP. The experimental isotherms were successfully fitted to the Langmuir−Freundlich model. Fixed-bed experiments of CO2 capture were carried out to evaluate the performance of the SILP sorbents at different operating conditions. All the breakthrough curves were well described by a linear driving force model. The obtained kinetic coefficients revealed that the CO2 sorption rate in fixed-bed linearly increases when decreasing the SILP particle size and increasing the operating temperature. Higher CO2 partial pressure in the inlet gas stream led to a faster mass transfer rate, affecting both the mass transfer driving force and kinetic coefficient. Aspen Adsorption simulator was successfully applied to model the fixed-bed operation, highlighting the role of the particle size on separation efficiency. Simulations results indicate that at very low CO2 partial pressure chemical absorption is the controlling step, while increasing that partial pressure shifts the regime toward diffusion into the SILP. This methodology will allow designing CO2 sorption systems based on SILPs that fulfill the separation requirements at given conditions (CO2 partial pressure and temperature), minimizing the SILP needs by optimizing the particle size and type of IL.Publicación Encapsulated Ionic Liquids to Enable the Practical Application of Amino Acid-Based Ionic Liquids in CO2 Capture(Academic Publishing International Limited, 2018-09-21) Lemus, Jesús; Moya, Cristian; Moreno, Daniel; Alonso Morales, Noelia; Palomar Herrero, José Francisco; Santiago Lorenzo, RubénThe performance of three amino-acid-based ionic liquids (aa-ILs) has been evaluated in CO2 capture by means of gravimetric measurements. The tested aa-ILs were 1-butyl-3- methylimidazolium prolinate, [Bmim][PRO]; 1-butyl-3-methylimidazolium methioninate, [Bmim][MET]; and 1-butyl-3-methylimidazolium glycinate, [Bmim][GLY]. First, the CO2 chemical absorption process was analyzed by in situ Fourier transform infrared spectroscopy−attenuated total reflection (FTIR-ATR), following the characteristic vibrational signals of the reactants and products, and comparing them with theoretical measurements obtained by quantum chemical calculations. This study let us confirm a mechanism of CO2 chemical absorption on amino-acid-based ILs. Then, gravimetric experiments were carried out to characterize the CO2 capture by aa-ILs. It was found that CO2 absorption quantification of these ILs was rather slow, because of their high viscosities, so alternative methodologies had to be employed to use them as absorbents in CO2 capture. In this sense, aa-ILs were encapsulated in porous carbon capsules (aa-ENIL), since it has been previously reported as material that defeats the kinetic limitations and preserves the favorable CO2 capture capacity of the neat ILs, promoting efficient chemical absorption. These aa-ENIL materials permit evaluation of CO2 capture at equilibrium and experimentally characterize the thermodynamics absorption phenomena, in terms of reaction enthalpy and the contribution of physical (H) and chemical (Keq) CO2 absorption for each IL. ENIL materials allow a fast CO2 capture with high sorption capacity and easy regeneration due to the favorable thermodynamics and kinetics of the process.Publicación Fatty alcohol/water reaction-separation platform to produce propylene carbonate from captured CO2 using a hydrophobic ionic liquid(Elsevier, 2021-11-15) Hernández, Elisa; Moya, Cristian; Vela, Sonia; Navarro, Pablo; Palomar Herrero, José Francisco; Santiago Lorenzo, RubénThe combined use of a hydrophobic ionic liquid catalyst and a fatty alcohol is presented to synergistically improve cycloaddition reaction of CO2 to epoxides producing cyclic carbonates and envision catalyst recovery by cyclic carbonate removal using water as extracting solvent. This approach is described for the production of propylene carbonate using trihexyl(tetradecyl)phosphonium 2-cyanopyrrolide catalyst -which chemically captures CO2 reactant- and 1-decanol/water mixture as extracting solvent. The novel use of fatty alcohols on CO2 cycloaddition reaction not only permits the effective separation of the catalyst and the product purification, but also improves the CO2 conversion in the reactor, and opens the challenge of process intensification by integrated CO2 capture and conversion.Publicación Siloxanes capture by ionic liquids: Solvent selection and process evaluation(Elsevier, 2020-12-01) Moya, Cristian; Palomar Herrero, José Francisco; Santiago Lorenzo, RubénNowadays, new technologies are being developed to substitute conventional energy resources. Biogas has emerged to avoid the intensification of global warming and promote waste valorization. However, undesirable chemicals must be removed prior to its utilization. Siloxanes stand out as biogas contaminants since they can damage process equipment’s. Therefore, in this work, COSMO-based/Aspen Plus computational methodology was applied to evaluate, as first-time, ionic liquids (ILs) as siloxanes absorbents on biogas upgrading context. Thus, molecular simulation using COSMO-RS method was used to analyze the interactions between siloxanes/ILs based on excess properties. Moreover, it was used to select the most promising ILs among a wide sample (9 0 0) of solvents for latter process simulation stage based on thermodynamics (Henry’s law constants) and kinetics (low viscosity). The results revealed that ILs with fluorinated anions are the best for the task. Then, the performance of selected ILs on siloxane capture at industrial scale was evaluated by means of Aspen Plus process simulations. Thus, the absorption efficiency in a packed column was analyzed by comparing the silicon concentration in outlet gas stream for each IL, using a rigorous RADFRAC column in Rate-base mode. Operating pressure inside the column was also studied as key operating variable. Last, simulations of the complete siloxane capture processes were carried out to treat a realistic biogas stream, including the analysis of both absorption and regeneration columns. Process simulation results revealed that thermodynamics is the key property for the selection of ILs for siloxanes capture. Moreover, most of the selected ILs can satisfy silicon outlet concentration legislation (< 5 mgSi/Nm3 ) in almost all the studied operating conditions. Last, solvent regeneration using air stripping column demonstrated the reversibility of the process in mild conditions of temperature (100 °C) and vacuum pressure (0.1 bar). In sum, ILs are proposed as promising siloxanes absorbents of siloxanes-containing streams, mainly focused on biogas upgrading.