Carbon dioxide sorbents for indoor air quality control
Disclosed in certain embodiments are carbon dioxide sorbents that include porous particles impregnated with an amine compound.
1. A sorbent comprising:
a gas-adsorbing material comprising an amine compound, wherein the amine compound is present in an amount ranging from 20% to 40% of a total weight of the sorbent;
a hydroxyl-containing additive comprising a silicon-based compound; and
porous support particles comprising granules formed by a powder impregnated with the gas-adsorbing material, the porous support particles comprising a clay, wherein the silicon-based compound forms a silicon-based coating on outer surfaces of the porous support particles.
2. The sorbent of claim 1 , wherein the gas-adsorbing material is coated onto the silicon-based coating.
3. The sorbent of claim 2 , wherein the silicon-based coating is present in an amount ranging from greater than 0% to 20% of a total weight of the porous support particles and the silicon-based coating.
4. The sorbent of claim 1 , wherein a weight loss of the sorbent after performing an attrition test is less than 3%, the attrition test being performed using a 5-penny attrition test in which the sorbent was mechanically vibrated with 5 pennies for 15 minutes and then sieved with a 250 micrometer filter, and a CO 2 adsorption capacity of the sorbent is greater than 6 g/L when the sorbent is maintained at a temperature greater than 20° C. and less than 40° C.
5. The sorbent of claim 2 , wherein the silicon-based coating was formed by treating the porous support particles with one or more of tetraethylorthosilicate, colloidal silica, or sodium silicate.
6. The sorbent of claim 1 , wherein a CO 2 adsorption capacity of the sorbent remains greater than 60% of an initial CO 2 adsorption capacity when the sorbent maintained at a temperature from 40° C. to 60° C. for up to 100 hours.
7. The sorbent of claim 1 , wherein the amine compound comprises molecular species each comprising at least two amine moieties.
8. The sorbent of claim 1 , wherein the amine compound comprises one or more of diethanolamine, triethylenepentamine, tetraethylenepentamine, pentaethylenehexamine, triethylenetetramine, bis(2-hydroxypropyl)amine, N,N′-bis(2-hydroxyethyl)ethylenediamine, monoethanolamine, diisopropanolamine, alkylamines, methylamine, linear polyethyleneimine, branched polyethyleneimine, dimethylamine, diethylamine, methyldiethanolamine, methylethanolamine, or polyethylene polyamines.
9. The sorbent of claim 1 , wherein a CO 2 adsorption capacity of the sorbent is greater than 8 g/L when the sorbent is maintained at a temperature greater than 20° C. and less than 40° C.
10. The sorbent of claim 1 , wherein the porous support particles further comprise one or more of bentonite, attapulgite, kaolinite, montmorillonite, ball clay, fuller's earth, hectorite, palygorskite, saponite, sepiolite, halloysite, silica, calcium sulfate, zeolite, synthetic zeolite, alumina, fumed silica, activated charcoal, or metal organic framework.
11. The sorbent of claim 1 , wherein the porous support particles comprise clay having silica coated thereon, wherein a surface area of the porous support particles is greater than 50 m 2 /g prior to impregnation with the gas-adsorbing material, and wherein an average pore volume of the sorbent is greater than 0.2 cc/g and less than 0.8 cc/g.
12. The sorbent of claim 1 , wherein the sorbent is in a form of one or more of the granules, the powder, a porous ceramic honeycomb, a metallic honeycomb, or a polymeric foam having the sorbent washcoated thereon.
13. The sorbent of claim 1 , wherein the granules have an average size ranging from about 0.25 mm to about 5 mm.
14. A sorbent comprising:
support particles comprising a clay, the support particles having a silicon-based coating formed on outer surfaces of the support particles, wherein the silicon-based coating is present in an amount from greater than 0% to 20% by weight based on a total weight of the support particles; and
a gas-adsorbing material comprising diethanolamine or pentaethylenehexamine, the support particles comprising granules formed by powder impregnated with the gas-adsorbing material, wherein the gas-adsorbing material comprises an amine compound, the amine compound being present in an amount ranging from 20% to 40% of a total weight of the sorbent.
15. The sorbent of claim 13 , wherein the powder has an average size ranging from about 1.0 μm to about 100 μm.