Assessing CO2 Adsorption on Amino-Functionalized Mesocellular Foams Synthesized at Different Aging Temperatures

Abstract

A wide variety of solid sorbents has recently been synthesized for application in CO 2 adsorption. Among them, mesoporous silicas deserve attention because of their ability to accommodate large concentrations of different chemicals as a consequence of their surface chemistry and tunable pore structure. Functionalized materials exhibit promising features for CO 2 adsorption at high temperatures and low CO 2 concentrations. This work aimed to assess the influence of the textural properties on the performance of CO 2 adsorption on functionalized mesoporous silica. With this goal, several mesoporous silica foams were synthesized by varying the aging temperature, obtaining materials with larger pore diameter. Thus, the synthesized materials were functionalized by grafting or impregnation with 3-aminopropyltriethoxysilane, polyethylenimine, and tetraethylenepentamine as amine sources. Finally, the amino functionalized materials were assessed for CO 2 capture by means of equilibrium adsorption isotherms at 25, 45, and 65°C. Among the most outstanding results, high aging temperatures favor the performance of impregnated materials by exposing greater pore diameters. Low or intermediate temperatures favor grafting by preserving an appropriate density of silanol groups.

Recent progress on (3-Aminopropyl)triethoxysilane (APTES) functionalized-adsorbent for CO2 capture

“…The highest CO2 adsorption capacity was obtained for the APTES functionalized MCF adsorbent produced at 80 o C aging temperature (APTES-MCF-80), which reaches a value of 1.45 mmol/g CO2 while raw adsorbent of MCF produced at room temperature aging (MCF-RT) only reaches 1.11 mmol/g CO2. However, the adsorption capacity will increase as aging temperature rises but will show a gradual decrease after certain temperature [17].…”

“…However, as compared to both non-functionalized ZIF-8/GOs, the post-functionalization in water has increased the capacity of the APTES-ZIF-8/GO. Furthermore, Gracia et al have investigated various mesoporous silica foams produced by changing the aging temperature, resulting in greater pore diameter materials [17]. As the aging temperature rises, IOP Publishing doi:10.1088/1742-6596/2259/1/012008 7 the specific surface area decreases.…”

Converting CO2 from a Harmful Gas to a Renewable Source of Matter and Energy: A Review

“…Moreover, enhanced hydrocarbon recovery based on a novel gas-gas separation method known as condensed rotational separation (CRS) is widely used for upgrading natural gas contaminated with H 2 S/CO 2 [19]. Also, CO 2 can be stored naturally or captured from industrial fumes (e.g., the Weyburn project) [20][21][22][23]. Urea is the most convenient product for fixing nitrogen.…”

CO2 Valorization and Its Subsequent Valorization

“…The design of porous silica with homogeneous and narrow pore distribution has also emerged in the last decades as adsorbent or catalytic support. In the same way, these porous silicas have been selected for CO 2 capture although the adsorption capacity was lower than that observed for the adsorbents indicated previously [ 13 , 14 ]. Clay minerals are other porous materials that have been tested to capture CO 2 .…”

“…In all cases, these adsorbents can improve their adsorption capacity by the incorporation of amine-species. The main strategies reported in the literature are grafting with amine-alkoxisilanes [ 16 ] or the impregnation of amine-rich polymers [ 13 , 14 ]. In both cases, the CO 2 adsorption capacity increases because of the existence of chemical interactions via zwitterion forming carbamate in dry conditions or bicarbonate under wet conditions [ 5 ].…”