title: Advanced buffer materials for indoor air CO2control in commercial buildings.
abstract: In this study, we evaluated solid sorbents for their ability to passively control indoor CO2concentration in buildings or rooms with cyclic occupancy (eg, offices, bedrooms). Silica supported amines were identified as suitable candidates and systematically evaluated in the removal of CO2from indoor air by equilibrium and dynamic techniques. In particular, sorbents with various amine loadings were synthesized using tetraethylenepentamine (TEPA), poly(ethyleneimine) (PEI) and a silane coupling agent 3-aminopropyltriethoxysilane (APS). TGA analysis indicates that TEPA impregnated silica not only displays a relatively high adsorption capacity when exposed to ppm level CO2concentrations, but also is capable of desorbing the majority of CO2by air flow (eg, by concentration gradient). In 10 L flow-through chamber experiments, TEPA-based sorbents reduced outlet CO2by up to 5% at 50% RH and up to 93% of CO2adsorbed over 8 hours was desorbed within 16 hours. In 8 m3flow-through chamber experiments, 18 g of the sorbent powder spread over a 2 m2area removed approximately 8% of CO2injected. By extrapolating these results to real buildings, we estimate that meaningful reductions in the CO2can be achieved, which may help reduce energy requirements for ventilation and/or improve air quality.
authors.affiliation: Department of Chemical & Biochemical Engineering, Missouri University of Science and Technology, Rolla, MO, USA.|Department of Civil, Architectural and Environmental Engineering, Missouri University of Science and Technology, Rolla, MO, USA.
authors.forename: P E
authors.initials: PE
authors.lastname: Rajan
authors.affiliation: Department of Chemical & Biochemical Engineering, Missouri University of Science and Technology, Rolla, MO, USA.
authors.forename: A
authors.initials: A
authors.lastname: Krishnamurthy
authors.affiliation: Department of Civil, Architectural and Environmental Engineering, Missouri University of Science and Technology, Rolla, MO, USA.
authors.forename: G
authors.identifier: http://orcid.org/0000-0001-6876-7185
authors.initials: G
authors.lastname: Morrison
authors.affiliation: Department of Chemical & Biochemical Engineering, Missouri University of Science and Technology, Rolla, MO, USA.
authors.forename: F
authors.identifier: http://orcid.org/0000-0002-4214-4235
authors.initials: F
authors.lastname: Rezaei
mesh_terms: D000327:Adsorption; D061808:Air Filters; D016902:Air Pollution, Indoor; D000588:Amines / Q000737:chemistry*; D002245:Carbon Dioxide / Q000302:isolation & purification*; D004780:Environment, Controlled; D012822:Silicon Dioxide
chemical_list: D000588:Amines; D002245:Carbon Dioxide; D012822:Silicon Dioxide
keywords: CO2 control; adsorption; chamber experiments; indoor air quality; supported amine sorbents