Examinando por Autor "Arencibia, A."

Mostrando 1 - 2 de 2

CO2 adsorption on amine-functionalized clays
(Elsevier B.V., 2019) Gómez-Pozuelo, G.; Sanz-Pérez, E.S.; Arencibia, A.; Pizarro, P.; Sanz, R.; Serrano, D.P.
Carbon capture using amine-modified porous sorbents is one of the main proposed technologies to reduce the CO2 atmospheric concentration. In this work, a wide series of inexpensive clays have been selected to assess their role as supports of amine-containing sorbents for CO2 capture. Montmorillonite, bentonite, saponite, sepiolite and palygorskite have been hydrated and functionalized by three routes: (a) grafting with aminopropyl (AP) and diethylenetriamine (DT) organosilanes; (b) impregnation with polyethyleneimine (PEI); and (c) double functionalization by impregnating previously grafted samples. XRD, FTIR and N2 adsorption-desorption analyses along with nitrogen content and CO2 adsorption properties (thermogravimetry and fixed bed) have been evaluated for bare and functionalized clays. Under dry conditions (45 °C, 1 bar), grafted and impregnated samples yielded CO2 uptakes as high as 61.3 and 67.1 mg CO2/g ads (for Sepi-DT and Paly-PEI, respectively), with the latter being the best-performing sample in terms of CO2 uptake. On the contrary, double-functionalized samples displayed poor CO2 adsorption properties, probably due to pore-blocking problems related to their high organic loading. The presence of 5% H2O in the feed gas resulted in CO2 uptake increments from 17 to 27%. The adsorption performance of AP, DT and PEI-containing samples was maintained after three adsorption-desorption cycles
CO2 adsorption performance of aminofunctionalized SBA-15 under post-combustion conditions
(Elsevier, 2013) Sanz-Pérez, E.S.; Olivares-Marín, M.; Arencibia, A.; Sanz, R.; Calleja, G.; Maroto Valer, M.M.
Carbon dioxide adsorbents prepared from SBA-15 mesostructured silica functionalized with amino groups have been tested under a simulated gas mixture similar to that of a coal-fired thermal power plant. SBA-15 material was functionalized by grafting with aminopropyl-trimethoxysilane (AP (N)) and diethylene-triamine-trimethoxysilane (DT (NNN)), and by impregnation with polyethyleneimine (PEI) and tetraethylenepentamine (TEPA). CO2 adsorption performance was measured in both a thermobalance and in a fixed bed. A thorough study of the adsorption behaviour was carried out, including the influence of conditions found in real post-combustion operation processes, such as diluted CO2 concentration, presence of SO2 and moisture in the flue gas. The reutilization of the adsorbent by successive adsorption-desorption experiments has also been tested. Grafted materials and samples impregnated with around 50 % organic amount or higher, showed a small influence of the dilution of CO2 in the feed gas on their CO2 uptake. Adsorption capacity after 10 cycles remains almost unaltered for grafted and PEIimpregnated solids and moderately decreases for TEPA-impregnated adsorbent. CO2 adsorption capacity decreased significantly with the presence of 1,000 ppm SO2 for up to 5 cycles, finding a direct correlation with the nitrogen content of the sorbents. Humid conditions (5 % moisture) do not significantly affect adsorption capacity of grafted samples, but improve the CO2 uptake of impregnated adsorbents about 50-60 %, obtaining an adsorption capacity of 16.2 wt. % CO2 (3.7 mmol CO2/g) for sample SBA-TEPA (50) in a humid diluted CO2 stream (15 % CO2) at 45 ºC and 1 bar.