Dipl. Ing. Matthias Mayerhofer Technische Universität München ...

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50 Experiments 6.3.3 Gas analysis in GC-FID After the sample is obtained, the quantification of tar is made in Gas Chromatographer-Flame Ionization Detector (GC-FID); Agilent Type 7890A.The amount obtained by sampling has to be a representative amount for the chromatographic analysis, so the determination of the concentration of the organic contaminants is facilitated. The calibration was made in-house. The eluted sample is injected into the GC at 250°C via a rubber septum, with hydrogen used as a gas carrier. The compounds are identified by the retention time which depends on the physical and chemical characteristics of the sample. The size of the spectral peak is proportional to the amount of the substance that reaches the detector in the GC instrument. The only disadvantage of this method is that because for o-xylol and styrol have similar retention times and the identification can be wrong. The error value of the device used in this work is ±7%.
Results and Discussion 51 7 Results and Discussion 7.1 Iron based Catalyst Characterization BET surface depends mainly on the amount of the support that is impregnated on the iron based catalyst. The catalyst in this study contains 16 wt% of Al2O3. Generally, Addition of alumina improves significantly the surface area, but the WGSR is decreased (Azhar Uddin,2008),(Noichi,2010). Hence, according to these studies the surface of the catalyst is expected ~ 40 m²/g and the obtained results indicated a surface area of 45.1 m²/g. The active surface area of the catalyst was measured after the tests and the result obtained was 15.6 m²/g. This indicates a significant decrease of the potential surface for reaction with the tar. According to the results from (Azhar Uddin,2008),in some cases the active surface area was also decreases more than 50% after the use of the catalyst. X-ray diffraction (XRD) patterns were recorded with PHILIPS X’Pert Pro System with a Cu-Karadiation of λ=0.154056 nm (45kV, 40mA) and step size 0,017° (40 sec/step). The measurements were acquired both for the fresh and used catalyst in order to determine the influence of the reduction and the interaction of the hydrocarbons with its crystallites. The measurements indicated that the Magnetite (Fe3O4) is much more intense in the fresh catalyst. Iron oxide (FeO), aluminum oxide (Al2O) and hematite (Fe2O3) are the main crystallites of the used catalyst. This is expected as after the use, the catalyst is more reduced iron state and it is more active. Scanning Electron Microscope was used to scan the fresh and used iron based catalyst. The used catalyst was observed to have grey and black particles, so with the microscope analysis, the point was to investigate whether this difference could be evident. In the following Figure 23: SEM image of Fresh catalyst Figure 24 and Figure 25 are presented the results from the measurements. From this measurement, the particle size growth is evident, and this could lead to possible deactivation. Still in these tests, the growth of the particles didn’t affect the catalyst’s performance. Figure 23: SEM image of Fresh catalyst
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Betreuer der Arbeit: Dipl. Ing. Mat
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Acknowledgements This work was acco
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II Content Content Acknowledgements
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IV List of Figures List of Figures
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VI List of Abbreviations List of Ab
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VIII Notation Notation ΔH [Kj/mol]
Page 17 and 18: Introduction 1 1 Introduction The d
Page 19 and 20: Introduction 3 1.2 Tasks The presen
Page 21 and 22: Biomass Gasification 5 2 Biomass Ga
Page 23 and 24: Biomass Gasification 7 Spouted Bed
Page 25 and 26: Biomass Gasification 9 2.2 Gas Clea
Page 27 and 28: Biomass Gasification 11 types of ca
Page 29 and 30: Biomass Gasification 13 Mechanical
Page 31 and 32: Biomass Gasification 15 Partial oxi
Page 33 and 34: Biomass Gasification 17 The followi
Page 35 and 36: Biomass Gasification 19 Groups of C
Page 37 and 38: Nickel Based Catalysts 21 even show
Page 39 and 40: Nickel Based Catalysts 23 The conte
Page 41 and 42: Nickel Based Catalysts 25 ing press
Page 43 and 44: Nickel Based Catalysts 27 3.4 Proce
Page 45 and 46: Iron Based Catalysts 29 4 Iron Base
Page 47 and 48: Iron Based Catalysts 31 Measurement
Page 49 and 50: Iron Based Catalysts 33 The percent
Page 51 and 52: Iron Based Catalysts 35 4.6 Catalys
Page 53 and 54: Iron Based Catalysts 37 Reduction i
Page 55 and 56: Iron Based Catalysts 39 and MgO (Di
Page 57 and 58: Precious Metal Catalysts 41 5 Preci
Page 59 and 60: Precious Metal Catalysts 43 Bimetal
Page 61 and 62: Experiments 45 Table 3: Biomass fee
Page 63 and 64: Experiments 47 6.3.1Experimental Pr
Page 65: Experiments 49 6.3.2 Tar Sampling M
Page 69 and 70: Results and Discussion 53 7.2 Sampl
Page 71 and 72: Results and Discussion 55 Wet Gas C
Page 73 and 74: Results and Discussion 57 er, the v
Page 75 and 76: Results and Discussion 59 7.3.1. Ef
Page 77 and 78: Results and Discussion 61 The conve
Page 79 and 80: Results and Discussion 63 7.3.3 App
Page 81 and 82: Results and Discussion 65 7.4 Blank
Page 83 and 84: Summary/Outlook 67 The aim is to pr
Page 85 and 86: References 69 (Aznar,1993) Aznar, M
Page 87 and 88: References 71 (Hepola,1997b) Hepola
Page 89 and 90: References 73 (Sarvaramini,2012) Sa
Page 91 and 92: 75 Appendix Appendix A: Iron based
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Dipl. Ing. Matthias Mayerhofer Technische Universität München ...

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