Examination of Activity of Oxidation Catalysts Toward Co and Hydrocarbon Emission Reduction from 4-Stroke Gasoline Carburetor Scooters in Tehran

Lotfollahzadeh Moghaddam, Alireza | 2020

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  1. Type of Document: M.Sc. Thesis
  2. Language: Farsi
  3. Document No: 52853 (06)
  4. University: Sharif University of Technology
  5. Department: Chemical and Petroleum Engineering
  6. Advisor(s): Hamzehlouyan, Tayebeh; Hosseini, Vahid
  7. Abstract:
  8. Over one million motorcycles operating in Tehran produce significant amounts of CO and unburnt hydrocarbons, thereby considered as one of the major contributors to air pollution in the city of Tehran. Oxidation catalysts, as emission control device, can reduce CO and hydrocarbon emissions from motorcycles. The efficiency of these catalysts under typical operating conditions of vehicles exhaust gas has been studied in the literature. However, due to the specific features of motorcycles exhaust gas in Tehran, such as low air to fuel ratio, different exhaust gas composition and significant amount of lubricating oil consumption, selection of a highly active, durable and cost-effective catalyst for motorcycles in Tehran is a challenge. Therefore in the present work, the activity of a commercial catalyst samples is evaluated under relevant operating conditions of Tehran’s motorcycles fleet and kinetic study of CO oxidation and C3H6 oxidation is performed. The commercial catalyst was provided by Baumot Company. Its charatecterization tests show that Pt and Pd are the active metal phase and Al2O3 is the washcoat. Steady state experiments showed that CO and C3H6 oxidation light off temperatures were 263C and 230C, respectively. For CO oxidation, the reaction order was -1.52 for CO and 0.49 for O2. Also for C3H6 oxidation, the C3H6 reaction order was 0.94 and O2 reaction order was -1.23. An apparent activation energy of CO and C3H6 oxidation was 159.52 kJ mol-1 and 81.27 kJ mol-1, respectively. CO high surface adsorption on Pt/Al2O3 cause self-inhibition for CO oxidation which decreases at high temperatures. Design of experiment approach was used to study the effect of CO, C3H6 and temperature on CO and C3H6 catalytic oxidation. 34 experiments were designed using Design Expert software. A mathematical model was presented for the conversion of CO and C3H6 oxidation. CO oxidation was affected most by CO concentration. Increase in O2 concentration enhanced the conversion in CO and C3H6 co-oxidation
  9. Keywords:
  10. Catalytic Activity ; Exhaust Gases ; Kinetics Study ; Exhaust Gas Emission ; Gas Refine ; Motorcycle Pollution ; Oxidation Catalysts

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