Final Report [electronic resource].
- Published
- Washington, D.C. : United States. Dept. of Energy, 2007.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy. - Additional Creators
- University of Florida, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information
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- Summary
- Forest products provide essential resources for human civilization, including energy and materials. In processing forest products, however, unwanted byproducts, such as volatile organic compounds (VOCs) and hazardous air pollutants (HAPs) are generated. The goal of this study was to develop a cost effective and reliable air pollution control system to reduce VOC and HAP emissions from pulp, paper and paperboard mills and solid wood product facilities. Specifically, this work focused on the removal of VOCs and HAPs from high volume low concentration (HVLC) gases, particularly methanol since it is the largest HAP constituent in these gases. Three technologies were developed and tested at the bench-scale: (1) A novel composite material of activated carbon coated with a photocatalyst titanium dioxide (TiO₂) (referred to as TiO₂-coated activated carbon or TiO₂/AC), (2) a novel silica gel impregnated with nanosized TiO₂ (referred to as silica-titania composites or STC), and (3) biofiltration. A pilot-scale reactor was also fabricated and tested for methanol removal using the TiO₂/AC and STC. The technical feasibility of removing methanol with TiO₂/AC was studied using a composite synthesized via a spay desiccation method. The removal of methanol consists of two consecutive operation steps: removal of methanol using fixed-bed activated carbon adsorption and regeneration of spent activated carbon using in-situ photocatalytic oxidation. Regeneration using photocatalytic oxidation employed irradiation of the TiO₂ catalyst with low-energy ultraviolet (UV) light. Results of this technical feasibility study showed that photocatalytic oxidation can be used to regenerate a spent TiO₂/AC adsorbent. A TiO₂/AC adsorbent was then developed using a dry impregnation method, which performed better than the TiO₂/AC synthesized using the spray desiccation method. The enhanced performance was likely a result of the better distribution of TiO2 particles on the activated carbon surface. A method for pore volume impregnation using microwave irradiation was also developed. A commercial microwave oven (800 W) was used as the microwave source. Under 2450 MHz microwave irradiation, TTIP was quickly hydrolyzed and anatase TiO2 was formed in a short time (< 20 minutes). Due to the volumetric heating and selective heating of microwave, the solvent and by-products were quickly removed which reduced energy consumption and processing time. Activated carbon and TiO₂/AC were also tested for the removal of hydrogen sulfide, which was chosen as the representative total reduced sulfur (TRS) species. The BioNuchar AC support itself was a good H₂S remover. After coating TiO₂ by dry impregnation, H₂S removal efficiency of TiO₂/AC decreased compared with the virgin AC due to the change of surface pH. Under UV light irradiation, H₂S removal efficiency of TiO₂/AC composite doubled, and its sulfate conversion efficiency was higher than that of AC. The formation of sulfate is preferred since the sulfate can be removed from the composite by rising with water. A pilot-scale fluidized bed reactor was designed to test the efficiency of methanol oxidation with TiO₂/AC in the presence of UV light. TiO₂/AC was prepared using the spray desiccation method. The TiO₂/AC was pre-loaded with (1) methanol (equivalent to about 2%wt) and (2) methanol and water. When the TiO₂/AC loaded with methanol only was exposed to UV light for one hour in the reactor, most of the methanol remained in the carbon pores and, thus, was not oxidized. The TiO₂/AC loaded with methanol and water desorbed about 2/3 of the methanol from its pores during fluidization, however, only a small portion of this desorbed methanol was oxidized. A biofilter system employing biological activated carbon was developed for methanol removal. The biofilter contained a mixed packing with Westvaco BioNuchar granular activated carbon, perlite, Osmocote slow release ammonium nitrate pellets, and Agrasoke water crystals in a 4:2:1:1...
- Report Numbers
- E 1.99:fsr 15
fsr 15 - Subject(s)
- Other Subject(s)
- Note
- Published through SciTech Connect.
06/30/2007.
"fsr 15"
David W. Mazyck; Angela Lindner; CY Wu, Rick Sheahan, Ashok Jain. - Type of Report and Period Covered Note
- Final; 04/23/2004 - 04/22/2007
- Funding Information
- FC36-03ID14437
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