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Book Gas phase Photocatalytic Oxidation of Organic Air Pollutants

Download or read book Gas phase Photocatalytic Oxidation of Organic Air Pollutants written by Svetlana Jõks and published by . This book was released on 2012 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Solving Widespread Low concentration VOC Air Pollution Problems

Download or read book Solving Widespread Low concentration VOC Air Pollution Problems written by and published by . This book was released on 1995 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many small businesses are facing new regulations under the 1990 Amendments to the Clean Air Act. Regulators, as well as the businesses themselves, face new challenges to control small point-source air pollution emissions. An individual business-such as a dry cleaner, auto repair shop, bakery, coffee roaster, photo print shop, or chemical company-may be an insignificant source of air pollution, but collectively, the industry becomes a noticeable source. Often the businesses are not equipped to respond to new regulatory requirements because of limited resources, experience, and expertise. Also, existing control strategies may be inappropriate for these businesses, having been developed for major industries with high volumes, high pollutant concentrations, and substantial corporate resources. Gas-phase photocatalytic oxidation (PCO) is an option for eliminating low-concentration, low-flow-rate emissions of volatile organic compounds (VOCs) from small business point sources. The advantages PCO has over other treatment techniques are presented in this paper. This paper also describes how PCO can be applied to specific air pollution problems. We present our methodology for identifying pollution problems for which PCO is applicable and for reaching the technology's potential end users. PCO is compared to other gas-phase VOC control technologies.

Book Solving Widespread Low Concentration VOC Air Pollution Problems  Gas Phase Photocatalytic Oxidation Answers the Needs of Many Small Businesses

Download or read book Solving Widespread Low Concentration VOC Air Pollution Problems Gas Phase Photocatalytic Oxidation Answers the Needs of Many Small Businesses written by and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many small businesses are facing new regulations under the 1990 Amendments to the Clean Air Act. Regulators, as well as the businesses themselves, face new challenges to control small point-source air pollution emissions. An individual business-such as a dry cleaner, auto repair shop, bakery, coffee roaster, photo print shop, or chemical company-may be an insignificant source of air pollution,but collectively, the industry becomes a noticeable source. Often the businesses are not equipped to respond to new regulatory requirements because of limited resources, experience, and expertise. Also, existing control strategies may be inappropriate for these businesses, having been developed for major industries with high volumes, high pollutant concentrations, and substantial corporateresources. Gas-phase photocatalytic oxidation (PCO) is an option for eliminating low-concentration, low-flow-rate emissions of volatile organic compounds (VOCs) from small business point sources. The advantages PCO has over other treatment techniques are presented in this paper. This paper also describes how PCO can be applied to specific air pollution problems. We present our methodology foridentifying pollution problems for which PCO is applicable and for reaching the technology's potential end users. PCO is compared to other gas-phase VOC control technologies.

Book Gas phase Photocatalytic Oxidation

Download or read book Gas phase Photocatalytic Oxidation written by Craig Steven Turchi and published by . This book was released on 1994 with total page 6 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Gas phase photocatalytic oxidation of volatile organic compounds

Download or read book Gas phase photocatalytic oxidation of volatile organic compounds written by Anna Kachina and published by . This book was released on 2008 with total page 85 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Volatile Organic Compounds By products Generation in Photocatalytic Oxidation Reactor

Download or read book Volatile Organic Compounds By products Generation in Photocatalytic Oxidation Reactor written by Mojtaba Malayeri and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The presence of volatile organic compounds (VOCs) in indoor air is inevitable. Their adverse effect on human health has encouraged researchers to develop various technologies for air pollution remediation. Photocatalytic oxidation (PCO) has been regarded as a promising and emerging technique for air purification and extensively investigated in the last two decades to characterize and improve the effectiveness and performance of this technology. In addition, the development of appropriate models can enhance the understanding of reactor performance and the evaluation of intrinsic kinetic parameters that enable the scale-up or re-design of more efficient large-scale photocatalytic reactors. This research works on mathematical modeling of gas phase photocatalytic reactors and analyses different key factors that can enhance pollutants decomposition. At the first step, a one-dimensional time-dependent mathematical model for continuous flow UV-PCO reactor has been developed. In this model, transfer of pollutants by advection and dispersion in bulk phase incorporates with the reaction rate based on the extended Langmuir Hinshelwood model in the catalyst phase. CFD modeling was also used to determine the flow distribution in the reactor at various airflow rates. Moreover, the light intensity distribution on the photocatalyst surface was simulated using the linear source spherical emission model. A dimensionless form of the model was then proposed to generalize the result for any scale. The proposed model was validated first by comparing with predictions of other models (inter-model comparison) and then by experimental data from two different scales (pilot and bench) of UV-PCO reactors. Furthermore, a sensitivity analysis using dimensionless parameters was conducted to find the controlling step in the PCO process. To validate the model, acetone, MEK, and toluene were tested in the UV-PCO reactor with a commercial PCO filter (TiO2 coated on silica fiber felts) at various operating conditions, such as concentration, relative humidity, irradiance and air velocity. The main issue for applying PCO technology in the indoor environment is the generation of hazardous by-products. The effect of by-products formation was usually ignored in former modeling studies. The next effort was to improve the model and build a comprehensive one to consider by-products generation in the UV-PCO reactor. To achieve this goal, a possible reaction pathway for degradation of each challenge compound was proposed based on identified by-products in analytical methods (GC-MS and HPLC). Different possible reaction rate scenarios were evaluated to find the best expression fitted to experimental data at the steady-state condition. The obtained reaction coefficients were then used to validate the model under various operating conditions. Finally, the Health Risk Index was used to investigate the implications of generated by-products on human health under varying operating conditions. The results indicated that the proposed model has a great potential to simulate the behavior of UV-PCO reactor in a real application.

Book Titanium Dioxide Photocatalyst Deactivation by Gas phase Oxidation of Polymethylsiloxane  PDMS  and Silicone Sealant Off gas in a Recirculating Batch Reactor

Download or read book Titanium Dioxide Photocatalyst Deactivation by Gas phase Oxidation of Polymethylsiloxane PDMS and Silicone Sealant Off gas in a Recirculating Batch Reactor written by Maurice K. Chemweno and published by . This book was released on 2004 with total page 158 pages. Available in PDF, EPUB and Kindle. Book excerpt: Indoor air quality is one of the most promising applications of photocatalytic oxidation. Rapid deactivation of the photocatalyst by ubiquitous indoor air pollutants would diminish the utility of photocatalytic technology. We have studied deactivation of TiO 2 photocatalyst by oxidation of PolyDiMethylSiloxane (PDMS) and silicone sealant off-gas in a recirculating batch reactor. The oxidation of the Si-containing vapor was monitored with an FTIR equipped with a gas cell. Subsequent to each incremental exposure, a hexane oxidation reaction was performed to track the TiO 2 catalyst activity. In this manner, loss of catalyst activity was quantitatively related to oxidation of Si-containing organic molecules. The exposures were repeated until a substantial deactivation was achieved. Surface science techniques were used to view the topography of the catalyst and to identify the elements causing the deactivation.

Book Photocatalytic Oxidation of Gas phase BTEX contaminated Waste Streams

Download or read book Photocatalytic Oxidation of Gas phase BTEX contaminated Waste Streams written by David A. Gratson and published by . This book was released on 1995 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Researchers at the National Renewable Energy Laboratory (NREL) have been exploring heterogeneous photocatalytic oxidation (PCO) as a remediation technology for air streams contaminated with benzene, toluene, ethyl-benzene, and xylenes (BTEX). This research is a continuation of work performed on chlorinated organics. The photocatalytic oxidation of BTEX has been studied in the aqueous phase,however, a study by Turchi et al. showed a more economical system would involve stripping organic contaminants from the aqueous phase and treating the resulting gas stream. Another recent study by Turchi et al. indicated that PCO is cost competitive with such remediation technologies as activated carbon adsorption and catalytic incineration for some types of contaminated air streams. In thiswork we have examined the photocatalytic oxidation of benzene using ozone (03) as an additional oxidant. We varied the residence time in the PCO reactor, the initial concentration of the organic pollutant, and the initial ozone concentration in a single-pass reactor. Because aromatic hydrocarbons represent only a small fraction of the total hydrocarbons present in gasoline and other fuels, wealso added octane to the reaction mixture to simulate the composition of air streams produced from soil-vapor-extraction or groundwater-stripping of sites contaminated with gasoline.

Book Photocatalytic Oxidation of Organic Pollutants in Aqueous and Gaseous Phases

Download or read book Photocatalytic Oxidation of Organic Pollutants in Aqueous and Gaseous Phases written by Marina Krichevskaya and published by . This book was released on 2003 with total page 77 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Photocatalytic Reaction Engineering

Download or read book Photocatalytic Reaction Engineering written by Hugo de Lasa and published by Springer Science & Business Media. This book was released on 2006-10-31 with total page 194 pages. Available in PDF, EPUB and Kindle. Book excerpt: Heterogeneous photocatalysis is a novel technique for water purification. Publications on photocatalysis span a relatively recent period of not more than 25 years. This is a technique that, according to our extensive experience on the development of laboratory scale and pilot plant units, has great promise to eliminate water and air pollutants. Photocatalysis offers much more than competitive techniques where pollutants are transferred from phases; photocatalysis can achieve complete mineralization of pollutants leaving non-toxic species such as CO2 and H2O and can be exploited at close to room temperature and ambient pressure.

Book Heterogeneous Photocatalysis

Download or read book Heterogeneous Photocatalysis written by M. Schiavello and published by . This book was released on 1997-10-09 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photocatalysis is a reaction which is accelerated by light while a heterogeneous reaction consists of two phases ( a solid and a liquid for example). Heterogeneous Photocatalysis is a fast developing science which to date has not been fully detailed in a monograph. This title discusses the basic principles of heterogeneous photocatalysis and describes the bulk and surface properties of semiconductors. Applications of various types of photoreactions are described and the problems related to the modeling and design of photoreactors are covered.

Book Photocatalytic Oxidation of Gas phase BTEX contaminated Waste Streams

Download or read book Photocatalytic Oxidation of Gas phase BTEX contaminated Waste Streams written by and published by . This book was released on 1995 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: Researchers at the National Renewable Energy Laboratory (NREL) have been exploring heterogeneous photocatalytic oxidation (PCO) as a remediation technology for air streams contaminated with benzene, toluene, ethyl-benzene, and xylenes (BTEX). This research is a continuation of work performed on chlorinated organics. The photocatalytic oxidation of BTEX has been studied in the aqueous phase, however, a study by Turchi et al. showed a more economical system would involve stripping organic contaminants from the aqueous phase and treating the resulting gas stream. Another recent study by Turchi et al. indicated that PCO is cost competitive with such remediation technologies as activated carbon adsorption and catalytic incineration for some types of contaminated air streams. In this work we have examined the photocatalytic oxidation of benzene using ozone (03) as an additional oxidant. We varied the residence time in the PCO reactor, the initial concentration of the organic pollutant, and the initial ozone concentration in a single-pass reactor. Because aromatic hydrocarbons represent only a small fraction of the total hydrocarbons present in gasoline and other fuels, we also added octane to the reaction mixture to simulate the composition of air streams produced from soil-vapor-extraction or groundwater-stripping of sites contaminated with gasoline.

Book Photocatalytic Oxidation of Gas Phase Volatile Organic Compounds Using Undoped and Metal Ions Doped Titanium Dioxide Thin Films

Download or read book Photocatalytic Oxidation of Gas Phase Volatile Organic Compounds Using Undoped and Metal Ions Doped Titanium Dioxide Thin Films written by Noor Khaida Wati Mohd. Saiyudi and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Surface Science

    Book Details:
  • Author : Kurt W. Kolasinski
  • Publisher : John Wiley & Sons
  • Release : 2008-04-30
  • ISBN : 9780470997819
  • Pages : 503 pages

Download or read book Surface Science written by Kurt W. Kolasinski and published by John Wiley & Sons. This book was released on 2008-04-30 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface chemistry is an essential and developing area of physical chemistry and one that has become increasingly interdisciplinary. The Second Edition of Surface Science: Foundations of Catalysis and Nanoscience has been fully revised and updated to reflect all the latest developments in the field and now includes an extensive discussion about nanoparticle growth and the quantum confinement effects in nanoscale systems. Two new chapters have been added and discuss The Liquid/Solid Interface and Non-Thermal Reactions, and Photon and Electron Stimulated Chemistry and Atom Manipulation. There are now many more worked examples included throughout to help students develop their problem-solving skills.

Book Photo catalytic Control Technologies of Flue Gas Pollutants

Download or read book Photo catalytic Control Technologies of Flue Gas Pollutants written by Jiang Wu and published by Springer. This book was released on 2018-09-20 with total page 162 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book introduces the theory and applications of nanometer photocatalysis, and it briefly presents the concept of photocatalysts, photocatalytic reaction mechanisms and kinetics, and photocatalytic reactor design. In addition, the use of photocatalysis in the control of flue-gas pollutants is discussed in detail. The book also describes how a photocatalytic reactor is designed and implemented to evaluate the photocatalytic oxidation capacity of different photocatalysts on elemental mercury in a simulated flue gas. After that, the effect of photocatalysts on the SO2, NOx and Hg removal in the flue gas is studied. Photocatalytic cleaning technology can be applied not only in gas pollutant cleaning at power plants, but also in wastewater purification. Readers gain a comprehensive understanding of possible mercury emission control methods and the industrial applications of these technologies.

Book Aquatic and Surface Photochemistry

Download or read book Aquatic and Surface Photochemistry written by George R. Helz and published by CRC Press. This book was released on 2018-01-10 with total page 665 pages. Available in PDF, EPUB and Kindle. Book excerpt: Aquatic and Surface Photochemistry provides a broad overview of current research in the emerging field of environmental aquatic and surface photochemistry. Selected reviews and current research articles are blended to provide an in-depth treatment of various aspects of this research area. The first part of the text deals with photochemistry in the environment, covering recent research on the following topics: aquatic photochemistry of organic pollutants and agrochemicals, photochemical cycling of carbon and transition metals (especially iron), photochemical formation of reactive oxygen species in natural waters, photoreaction in cloud and rain droplets, and photoreactions on environmental surfaces (soil, ash, metal, oxide). The second part provides discussions and data on both heterogeneous photocatalytic and homogeneous processes, with topics ranging from applications to mechanistic studies. These chapters illustrate the wide diversity of pollutant classes that are degradable by photochemical techniques and the effects of various reaction conditions on the rates and efficiency of the techniques. Current kinetic studies are presented, which provide new information about the role of adsorption and the nature of the reactive oxidizing species that mediate these photoremediation processes.This book will interest civil, chemical, and environmental engineers, as well as chemists, soil scientists, geochemists, and atmospheric chemists.