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- Resumen es exacto "This thesis focuses on the development of CO2 sorbent materials, which can be used with a NiMgAl catalyst previously developed in this research group. These materials are intended for sorption-enhanced ethanol steam reforming reaction, aiming high-purity H2 production. The study encompasses two groups of materials: CaO and its derivatives, and K-promoted MgAl Layered Double Oxides. The synthesized materials underwent comprehensive characterization using various techniques, including: thermogravimetric analysis coupled with differential thermal analysis (TGA-DTA); N2 sorptometry, to describe its textural characteristics; powder X ray diffraction (PXRD), to determine the phases present in each material and its structural characteristics; CO2 temperature programmed desorption (TPD-CO2), to analyze the basic character of the samples; these results were complemented by FTIR-ATR technique; inductively coupled plasma optical emission spectrometry for chemical composition determination; and scanning electron microscopy (SEM), for morphological comparisons. In the first group, the sorbent materials were developed by partial substitution of CaO with an inert phase called mayenite (Ca12Al14O33). In this way, two solids were obtained: D85 with 85 % w/w CaO, and D75 with 75 % w/w CaO. A comparison between pure CaO and its derivatives was conducted to assess the effect of the mayenite phase on sorbents textural and structural characteristics and on their performance in the multi-cycle CO2 sorption-desorption operation and on sorption-enhanced ethanol steam reforming (SE-ESR) to produce high-purity H2., as well. D85 demostrated the highest stability and the highest CO2 sorption capacity in the multi-cycle sorption-desorption operation. In the sorption-enhanced ethanol steam reforming, this derivative allows to obtain high-purity H2 (above 95 %) and CO purities equal to or less than 2.5 % over 20 reaction-regeneration cycles. Kinetic studies for carbonation reactions of CaO and D85 showed similar kinetics parameters (activation energy and preexponential factor) with a first-order dependency on CO2 partial pressure. For the second group of sorbents, a MgAl Layered Double Oxide was modified with varying K contents (0 %, 10 %, 15 %, and 20 % w/w). The addition of K increased the proportion of strong basic sites, enhancing material performance. Solid modified with 15 and 20 %w/w of K exhibited the best results over 20 cycles of CO2 adsorption desorption, showing the highest stability and cyclic adsorption and desorption capacities. Regarding the sorption-enhanced ethanol steam reforming, high H2 purities (close to 100 % during the breakthrough) and CO contents below 5 % were observed over 20 cycles using the sorbents with 15 and 20 %w/w of K."
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