title: Alkaline modified oil shale fly ash: optimal synthesis conditions and preliminary tests on CO2 adsorption.
abstract: Environmentally friendly product, calcium-silica-aluminum hydrate, was synthesized from oil shale fly ash, which is rendered so far partly as an industrial waste. Reaction conditions were: temperature 130 and 160°C, NaOH concentrations 1, 3, 5 and 8M and synthesis time 24h. Optimal conditions were found to be 5M at 130°C at given parameter range. Original and activated ash samples were characterized by XRD, XRF, SEM, EFTEM, (29)Si MAS-NMR, BET and TGA. Semi-quantitative XRD and MAS-NMR showed that mainly tobermorites and katoite are formed during alkaline hydrothermal treatment. Physical adsorption of CO(2) on the surface of the original and activated ash samples was measured with thermo-gravimetric analysis. TGA showed that the physical adsorption of CO(2) on the oil shale fly ash sample increases from 0.06 to 3-4 mass% after alkaline hydrothermal activation with NaOH. The activated product has a potential to be used in industrial processes for physical adsorption of CO(2) emissions.
authors.affiliation: National Institute of Chemical Physics and Biophysics, Akadeemia tee 23, EE-12618, Tallinn, Estonia. jreinik@kbfi.ee
authors.forename: Janek
authors.initials: J
authors.lastname: Reinik
authors.forename: Ivo
authors.initials: I
authors.lastname: Heinmaa
authors.forename: Uuve
authors.initials: U
authors.lastname: Kirso
authors.forename: Toivo
authors.initials: T
authors.lastname: Kallaste
authors.forename: Johannes
authors.initials: J
authors.lastname: Ritamäki
authors.forename: Dan
authors.initials: D
authors.lastname: Boström
authors.forename: Eva
authors.initials: E
authors.lastname: Pongrácz
authors.forename: Mika
authors.initials: M
authors.lastname: Huuhtanen
authors.forename: William
authors.initials: W
authors.lastname: Larsson
authors.forename: Riitta
authors.initials: R
authors.lastname: Keiski
authors.forename: Krisztián
authors.initials: K
authors.lastname: Kordás
authors.forename: Jyri-Pekka
authors.initials: JP
authors.lastname: Mikkola
mesh_terms: D000327:Adsorption; D000468:Alkalies; D017610:Calcium Compounds / Q000138:chemical synthesis* / Q000737:chemistry; D002245:Carbon Dioxide / Q000302:isolation & purification*; D060729:Coal Ash; D009682:Magnetic Resonance Spectroscopy; D008855:Microscopy, Electron, Scanning; D046529:Microscopy, Electron, Transmission; D009821:Oils / Q000737:chemistry*; D012037:Refuse Disposal / Q000379:methods*; D017640:Silicates / Q000138:chemical synthesis* / Q000737:chemistry; D013052:Spectrometry, X-Ray Emission; D013499:Surface Properties; D013818:Thermogravimetry; D014961:X-Ray Diffraction
chemical_list: D000468:Alkalies; D017610:Calcium Compounds; D060729:Coal Ash; D009821:Oils; D017640:Silicates; C512534:tobermorite; D002245:Carbon Dioxide