Dissertation > Excellent graduate degree dissertation topics show

Studies on the Cobalt and Ruthenium Catalysts Supported on Silica Nanotubes for Fischer-Tropsch Synthesis

Author: TangHuoQiang
Tutor: LiJinLin
School: Central South University for Nationalities
Course: Physical and chemical
Keywords: Fischer-Tropsch synthesis Cobalt Ruthenium Catalyst Activity Selectivity Silica nanotubes
CLC: TQ529.2
Type: Master's thesis
Year: 2011
Downloads: 21
Quote: 0
Read: Download Dissertation

Abstract


Fischer-Tropsch synthesis （FTS） is an important route to catalytically convert syngas （CO and H2） to clean fuels. For the development of Fischer-Tropsch catalysts, one of the most important goals is to develop the cobalt catalyst with high FTS reaction activity and high long chain hydrobarbon selectivity. In the present work, SNT was synthesized using CNT as a template, and used as a support to prepare cobalt and ruthenium catalysts.All cobalt catalysts were prepared by incipient wetness impregnation.All ruthenium catalysts were prepared by slurry impregnation. The catalysts were characterized using different techniques such as N2 physisorption measurement, X-ray diffraction （XRD）, transmission electron microscopy（TEM）, temperature-progra -mmed reduction （H2-TPR）. The catalyst activity and selectivity were evaluated in a fixed-bed reactor under typical hydrocarbon synthesis conditions. The main results are as follows:1. For Ru/SNT catalysts, silica nanotube （SNT） was synthesized by using the carbon nanotube （CNT） as a template, the catalysts were prepared by slurry impregnation. Ruthenium particles were found to disperse mainly inside the nanotubes. The Ru/SNT catalyst had a good catalytic activity, while Ru/SiO2 catalyst showed a poor catalytic activity due to large Ru particles and the poor dispersion. The larger Ru particles are more selective for heavier hydrocarbons for F-T synthesis.2. Silica coated carbon nanotubes （SNT-CNT） and SNT were used to load cobalt catalyst in Fischer-Tropsch synthesis （FTS）. The catalysts were also prepared by incipient wetness impregnation. The Co/SNT catalyst showed the best catalytic performance because of high degree of reduction. Co/SNT-CNT catalyst had a poor catalytic performance, which was attributed to the low BET specific surface area of SNT-CNT, the large cobalt particle and poor dispersion. The high CH4 selectivity of Co/CNT might be due to the small cobalt particle size as well as the ease of gasification of the carbon to produce CH4 under the hydrogen atmosphere.3. SiO2、SBA-15 and SNT were used as supports to prepare cobalt catalysts FTS. The catalysts were prepared by incipient wetness impregnation. The three catalysts in F-T synthesis showed the similar activity for FTS, but the selectivity was different. The Co/SNT catalyst showed the high C5+ selectivity and low CH4 selectivity. The cobalt particle size in Co/SNT is the largest among those catalysts, so the higher C5+ selectivity is thus expected. The Co/SiO2 catalyst showed the high CH4 selectivity, due to the unreduced cobalt oxides which can catalyze the WGS reaction, resulting in an increasing in H2/CO ratio on the catalyst surface. This led to both an increase in methane selectivity and CO2 selectivity.

Related Dissertations

  1. Study on the Syntheses and Antibacterial Acticity of Metal Organic Complexes Built from Three Carboxylate Ligands,O621.13
  2. Studies on Synthesis, Characterization and Properties of Fe-V Co-doped TiO2 Catalyst,O614.411
  3. Study on Using Sepiolite As Supported Catalysts in Selective Hydrogenation of Cinnamaldehyde to Cinnamyl Alcohol,O643.32
  4. Synthesis and Characterization of Monovalent, Divalent Imidazolium Ionic Liquids Containing Hydrocarbons,O621.3
  5. Extraction, Purification and Antifungal Activity of Anthocyanins in Drop Fruits of Chinese Baberry,TQ914.1
  6. Theeffect of Environmental Factor on Rooting Culture of Paeonia Suffruticosa in Vitro,S685.11
  7. Effects of Organic, Specially Grown and Conventiinal Farming Systems on Vegetable Yield, Quality and Soil Fertility in Nanjing Region,S63
  8. Isolation and Identification of Pyrene-Degrading Strain SE12 and Its Degrading Effect,X172
  9. The Basicity of MO/ZrO2 Catalyst and Their Use in the Synthesis of 2-Ethyl-Hexyl Carbonate,O623.662
  10. Water-soluble hypocrellin / titanium dioxide dosing system and its properties of,TQ460.1
  11. Isolation, Purification and Antioxidant Activity of Proteins from Chinese Yam,TS255.1
  12. Syntheses of Novelbenzopyran Compounds Containing Fluorine and Induced Resistance to TMV,S435.72
  13. Preparation of Essence and Residues Powder from Flammulina Velutipes and Evaluation of Their Physical-Chemical Properties,S646.15
  14. Research on the Quility of Pear and Soil Physical and Chemical Properties in Crop-Animal Mixed Orchard,S661.2
  15. Study on the Pathogenesis of Soil-Borne Fusarium Wilt of Cucumber and Biological Control,S436.421
  16. The Involvement of Heme Oxygenase/Carbon Monoxide System in Cobalt Chloride-Induced Lateral Root Development in Tomato Seedlings,S641.2
  17. Biochemical and Molecular Markers and Genetic Model Analysis of Bolting Traits in Non-Heading Chinese Cabbage,S634.3
  18. Process Selenuum Enriched Flos Chrysanthemi and Its Antioxidative Activity,S682.11
  19. More than enough calcium and magnesium metal ligand complexes Synthesis, Structural Characterization and Antibacterial Activity,O641.4
  20. Rubber - cobalt - nickel- Preparation of adhesion promoters,TQ430.1
  21. Ru-catalyzed Cross Couping Reaction Via C-H Activation Using Arylbronic Acids,O643.32

CLC: > Industrial Technology > Chemical Industry > Coke chemical industry > Coal liquefaction > Indirect liquefaction
© 2012 www.DissertationTopic.Net  Mobile