title: Removal of BTEX vapours from waste gas streams using silica aerogels of different hydrophobicity.
abstract: Silica aerogels are alternative adsorbents to activated carbon (AC) for the removal and the recovery of organic vapours from gas streams. The adsorption capacity measurements of different silica aerogels were done by mini-column method. Continuous adsorption measurements show that silica aerogels are excellent adsorbents of BTEX vapours from waste gas stream. Compared to the most used adsorbents, such as AC and silica gel, aerogels exhibit capacities which enormously exceed that of both commonly used adsorbents. By increasing the degree of hydrophobicity, aerogels become less effective, but they do not adsorb water vapour from gas stream. Silica monolith aerogels with different degrees of hydrophobicity by incorporating methyltrimethoxysilane (MTMS) or trimethylethoxysilane (TMES) in standard sol-gel synthesis were prepared. Excellent properties of aerogels, obtained with the sol-gel synthesis, were preserved with supercritical drying with CO(2). The degree of hydrophobicity of the aerogels was tested by measuring the contact angle (theta) of a water droplet with the aerogel surface. The aerogels were also characterised by FTIR, nitrogen sorption and DSC/TG measurements.
authors.affiliation: Faculty of Chemistry and Chemical Engineering, University of Maribor, Maribor, Slovenia.
authors.forename: Suzana
authors.initials: S
authors.lastname: Standeker
authors.forename: Zoran
authors.initials: Z
authors.lastname: Novak
authors.forename: Zeljko
authors.initials: Z
authors.lastname: Knez
mesh_terms: D000393:Air Pollutants / Q000302:isolation & purification*; D001554:Benzene / Q000302:isolation & purification; D001555:Benzene Derivatives / Q000302:isolation & purification*; D005740:Gases; D005782:Gels; D057927:Hydrophobic and Hydrophilic Interactions; D007220:Industrial Waste / Q000517:prevention & control*; D012822:Silicon Dioxide; D014050:Toluene / Q000302:isolation & purification; D014992:Xylenes / Q000302:isolation & purification
chemical_list: D000393:Air Pollutants; D001555:Benzene Derivatives; D005740:Gases; D005782:Gels; D007220:Industrial Waste; D014992:Xylenes; D014050:Toluene; D012822:Silicon Dioxide; D001554:Benzene