Title: | "Low-temperature catalytic oxidation of aldehyde mixtures using wood fly ash: kinetics, mechanism, and effect of ozone" |
Address: | "Biological and Agricultural Engineering, Weaver Labs, North Carolina State University, Raleigh, NC 27695-7625, USA. pkolar@ncsu.edu" |
DOI: | 10.1016/j.chemosphere.2009.12.033 |
ISSN/ISBN: | 1879-1298 (Electronic) 0045-6535 (Linking) |
Abstract: | "Poultry rendering emissions contain volatile organic compounds (VOCs) that are nuisance, odorous, and smog and particulate matter precursors. Present treatment options, such as wet scrubbers, do not eliminate a significant fraction of the VOCs emitted including, 2-methylbutanal (2-MB), 3-methylbutanal, and hexanal. This research investigated the low-temperature (25-160 degrees C) catalytic oxidation of 2-MB and hexanal vapors in a differential, plug flow reactor using wood fly ash (WFA) as a catalyst and oxygen and ozone as oxidants. The oxidation rates of 2-MB and hexanal ranged between 3.0 and 3.5 x 10(-9)mol g(-1)s(-1) at 25 degrees C and the activation energies were 2.2 and 1.9 kcal mol(-1), respectively. The catalytic activity of WFA was comparable to other commercially available metal and metal oxide catalysts. We theorize that WFA catalyzed a free radical reaction in which 2-butanone and CO(2) were formed as end products of 2-MB oxidation, while CO(2), pentanal, and butanal were formed as end products of hexanal oxidation. When tested as a binary mixture at 25 and 160 degrees C, no inhibition was observed. Additionally, when ozone was tested as an oxidant at 160 degrees C, 100% removal was achieved within a 2-s reaction time. These results may be used to design catalytic oxidation processes for VOC removal at poultry rendering facilities and potentially replace energy and water intensive air pollution treatment technologies currently in use" |
Keywords: | Air Pollutants/*chemistry Aldehydes/*chemistry Carbon/*chemistry Catalysis Coal Ash Cold Temperature Kinetics Oxidation-Reduction Ozone/*chemistry Particulate Matter/*chemistry Volatile Organic Compounds/chemistry Wood/*chemistry; |
Notes: | "MedlineKolar, Praveen Kastner, James R eng England 2010/01/13 Chemosphere. 2010 Feb; 78(9):1110-5. doi: 10.1016/j.chemosphere.2009.12.033. Epub 2010 Jan 12" |