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

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54 Results and Discussion Table 6: LHV dependency on operational parameters for Iron based catalysts Gas LHV (KJ/Kg) Space Velocity (1/h) Temperature (°C) 7652 4500 800 7486 6500 750 7546 6500 800 7750 6500 860 7434 8500 800 7200 10000 800 Table 7: LHV dependency on operational parameters for Nickel based catalyst at 800°C Gas LHV (KJ/Kg) Space Velocity (1/h) 8159 6500 8161 10000 8228 12500 8188 14500 Table 8: LHV dependency on operational parameters for precious metal catalysts at 800°C Gas LHV (KJ/Kg) Space Velocity (1/h) 8248 4500 7546 6500 7750 10000 In the following Figure 27and Figure 28 the gas composition in the presence of iron based catalysts is presented. It is easily concluded that Le Chatelier’s principle affects a lot the result of the product gas. The CO2 is decreased both with the raise of temperature and the decrease of the residence time. In comparison, CO increases in both cases and CH4 and H2 are stable. There is a wide range of equations that either consume or produce these components. However, the mechanism of their occurrence and the exact influence of each one of these equations are not exactly known, but probably the water gas shift reaction is the most dominate. The fact that the H2O value decreases compared to the one obtained before the catalyst indicates that it is consumed for steam reforming of tar.
Results and Discussion 55 Wet Gas Composition (%) Wet Gas Composition Vol (%) 40 35 30 25 20 15 10 5 0 750 800 860 Figure27: Iron catalyst-Wet gas composition-Temperature dependence 40 35 30 25 20 15 10 5 0 Temperature (°C) 4500 6500 8500 10000 Space Velocity (1/h) Figure28: Iron catalyst-Wet gas composition-SV dependence As the tar conversion was higher with the use of nickel based catalysts we can see a significant difference in the gas composition in Figure 29. Hydrocarbons are apparently fully converted, so CH4 is almost zero and the CO value is increased. As a result of the water-gas shift reaction and methane reforming, the production of H2 is much higher as well as the value of CO2. Of course steam is a lot lower (~27.5%) in the gas composition after the catalyst the before the bed (~ 43%), due to the steam reforming. It also clear that as the residence time decreases, the catalyst works better, but still in all the operating conditions it efficient enough. CH₄ CO CO₂ H₂ H₂O CH₄ CO CO₂ H₂ H₂O
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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]
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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 and 66: Experiments 49 6.3.2 Tar Sampling M
Page 67 and 68: Results and Discussion 51 7 Results
Page 69: Results and Discussion 53 7.2 Sampl
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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