Large-Pore Mesostructured Silica Impregnated with Blended Amines for CO₂ Capture

Abstract

Mesoporous silica materials with different pore volumes were functionalized by wet impregnation with a variety of amines for the purpose of CO 2 adsorption. The effects of the concentration and composition of amine blends, silica supports, and adsorption temperature on CO 2 adsorption were investigated. The mechanism of an observed synergistic effect between blended amines is also discussed. The experimental results showed that in addition to the pore volume of the supports and the adsorption temperature the molecular functional groups of the blended amines play an important role and greatly affect the CO 2 adsorption capacity. The silica material with the largest pores (MSU-F) had the highest CO 2 adsorption capacity after impregnation with a mixture of 40 wt % tetraethylenepentamine and 30 wt % diethanolamine. For 100 kPa CO 2 , the adsorption capacity at 50 °C was 5.91 mmol/g.

Carbon Dioxide Absorption using Solid Sorbents Incorporating Purified Components of Tetraethylenepentamine

“…Interestingly, the capacity of crude TEPA (e.g., 2.53 mmol g −1 at 100 kPa during the first cycle) is higher than the average based on composition (2.24 mmol g −1 ) and those of the pure components. This is likely due to synergistic effects of blending, as has been reported for several blended systems . The formation of stable carbamate with T‐BRN and T‐LIN and decreased CO 2 diffusion resistance by T‐IPZ and T‐EPZ work concertedly; therefore, crude TEPA has the highest capacity for CO 2 absorption.…”

Carbon dioxide adsorption by zinc-functionalized ionic liquid impregnated into bio-templated mesoporous silica beads

“…The increase in k 2 despite the reduction in SSA and V p points out to the effect of the nature of interaction to be an additional factor that describes the kinetics in this intermediate step. The chemisorptive nature of the uptake by EZT3 compensated for the negative effect of impregnation on the textural properties resulting in an increase in the overall capacity of the sorbent, which is similarly observed in amine-impregnated porous silica supports[21,58,66,[68][69][70]. The rate constant at the extended region (k 3 ) is comparable with bulk EZT3 suggesting saturation of sorption sites.…”

Surfactant Mediated CO2 Adsorption; the Role of the Co- impregnation Species

“…This appears to explain the significant increases in performance obtained by Dao et al who noted a maximum in single component CO 2 adsorption at 40 °C on a binary TEPA, diethanolamine adsorbent. [10] The low temperature component of these adsorbents could be attributed to physisorption of CO 2 , hence in the presence of humid conditions these physisorption sites could be replaced by water.…”

“…Further work by Dao studied blends of TEPA and a range of low molecular weight amines and hydroxyl bearing groups, finding no significant influence that could be ascribed to the presence of hydroxyl groups alone. [10] It has been shown that non-ionic surfactants bearing long hydrophobic chains and hydroxylated head groups increase the adsorption capacity. This increase in capacity was related to an increase in the accessibly brought about by the disruptive nature of the surfactants.…”