Search for dissertations about: "Deactivation processes"

Showing result 1 - 5 of 48 swedish dissertations containing the words Deactivation processes.

2. 1. Study of Catalyst Deactivation in Three Different Industrial Processes

   Author : Ann-Charlotte Larsson; Mehri Sanati; Ferruccio Trifiro; Växjö universitet; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; deactivation; catalyst; SCR; VOC; steam reforming; aerosol particle; potassium; zinc; ash salts; biomass; organosilicon; Chemical engineering; Kemiteknik; Kemi; Chemistry;

   Abstract : Deactivation of catalysts were investigated focusing on three industrial processes: 1) Selective Catalytic Reduction (SCR) for abatement of NOx from biomass combustion using V2O5-WO3 /TiO2 catalysts; 2) Catalytic oxidation of volatile organic compounds (VOC) from printing industries using a Pt/γ-Al2O3 catalyst; and 3) Ni and Pt/Rh catalysts used in steam reforming reaction of bio-syngas obtained from biomass gasification.The aim has been to simulate industrial conditions in laboratory experiments in order to comprehend influence of compounds affecting catalysts performance. READ MORE

4. 2. Hydrodeoxygenation (HDO) catalysts Characterization, reaction and deactivation studies

   Author : Houman Ojagh; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; NATURVETENSKAP; NATURAL SCIENCES; Poisoning; Carbon deposition; Ring opening; Hydrodeoxygenation HDO ; Deactivation; Hydroconversion; Brønsted acid sites; Renewable diesel; Sulfided phase;

   Abstract : Production of biomass derived fuels such as renewable diesel, are primarily intended to reduce the reliance of the conventional engines on petroleum fuels as well as the emission of CO2 from fossil hydrocarbons. Hydrodeoxygenation (HDO) is a powerful technique that has been regularly used in the fuel upgrading processes. READ MORE

5. 3. Photo-induced molecular processes and charge recombination reactions driven by non-adiabatic couplings

   Author : Michael Stenrup; Åsa Larson; Horst Köppel; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Non-adiabatic processes; Photophysics; Photochemistry; Radiationless deactivation; Conical intersections; Five-membered aromatic heterocyclic compounds; Mutual neutralization; Dissociative recombination; kemisk fysik; Chemical Physics;

   Abstract : This thesis is based on a number of theoretical studies of molecular processes in which non-adiabatic effects play a crucial role. The main part is devoted to the photophysics and photochemistry of five-membered aromatic heterocyclic compounds, with particular focus on furan and thiophene. READ MORE

6. 4. Deactivation of diesel oxidation catalysts

   Author : Jonas Andersson; Chalmers tekniska högskola; []
   Keywords : TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Accelerated aging: Diesel exhaust: Oxidation catalyst: Sulfur deactivation: Phosphorous poisoning: CO oxidation: Pt dispersion: Al2O3: Sintering: TEM: XPS;

   Abstract : To meet the demand for heavy- and light-duty diesel vehicles on expansive markets while complying with current and future emission standards, it is necessary to reinsure the long-livety of the applied exhaust aftertreatment technology. Loss of catalytic performance may be associated with environmental as well as economical consequences. READ MORE

7. 5. Exploring Organic Dyes for Grätzel Cells Using Time-Resolved Spectroscopy

   Author : Ahmed M. El-Zohry; Burkhard Zietz; Ana Morandeira; Leif Hammarström; Eric Vauthey; Uppsala universitet; []
   Keywords : Laser spectroscopy; DSSCs; DSC; Electron dynamics; Deactivation processes; Isomerization; Twisting; TICT; Quenching by protons; Semiconductor; Electrolyte; Electron injection; Regeneration; Recombination; Chemistry with specialization in Physical Chemistry; Kemi med inriktning mot fysikalisk kemi; Kemi med inriktning mot kemisk fysik; Chemistry with specialization in Chemical Physics;

   Abstract : Grätzel cells or Dye-Sensitized Solar Cells (DSSCs) are considered one of the most promising methods to convert the sun's energy into electricity due to their low cost and simple technology of production. The Grätzel cell is based on a photosensitizer adsorbed on a low band gap semiconductor. READ MORE