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

IV List of Figures
List of Figures
Figure 1: Biomass Gasification ...................................................................................................... 5
Figure 2: Entrained flow bed (Basu,2010) ..................................................................................... 6
Figure 3: Fixed or moving bed (Basu,2010) .................................................................................. 6
Figure 4: Spouted bed (Basu,2010) .............................................................................................. 7
Figure 5: Bubbling Fluidized bed (Basu,2010) .............................................................................. 7
Figure 6: Circulating Fluidized bed (Basu,2010) ........................................................................... 8
Figure 7: Typical compositions of biomass tar (Coll,2001) ......................................................... 12
Figure 8: Catalyst contribution in reaction progress .................................................................... 17
Figure 9: Langmuir-Hinshelwo and Eley-Riedeal mechanism ................................................... 18
Figure 10: Composition of Ni-based catalysts ............................................................................. 20
Figure 11: Sulfur poisoning of Ni-based catalysts ....................................................................... 22
Figure 12: Sulpfur formation (Lassi,2003) ................................................................................... 23
Figure 13: Carbon formation (Lassi,2003) ................................................................................... 24
Figure 14: Particles sintering (Lassi,2003) .................................................................................. 25
Figure 15: Ellingham lines (Nordgreen,2012).............................................................................. 33
Figure 16: Mechanism of decomposition of tar on a calcinated scallop shell ............................. 39
Figure 17 : Orifice Plate ............................................................................................................... 44
Figure 18: Overview of the facility ............................................................................................... 45
Figure 19 : Catalyst Bed .............................................................................................................. 46
Figure 20: Reduction of Iron based catalyst ................................................................................ 47
Figure 21: Reduction of Nickel based catalyst ............................................................................ 48
Figure 22: SPA sampling method (Ziad Abu El-Rub 2008) ......................................................... 49
Figure 23: SEM image of Fresh catalyst ..................................................................................... 51
Figure 24: SEM image of Used Catalyst, grey particles .............................................................. 52
Figure 25: SEM of Used Catalyst, black particles ....................................................................... 52
Figure 26: Gas composition before catalyst test rig .................................................................... 53
Figure 27: Iron catalyst-Wet gas composition-Temperature dependence .................................. 55
Figure 28: Iron catalyst-Wet gas composition-SV dependence .................................................. 55
Figure 29: Nickel catalyst-Wet gas Composition-SV dependence .............................................. 56
Figure 30: Precious metal catalyst-Wet gas composition-SV dependence ................................ 56
Figure 31: Change of wet gas composition of CH4 with time ...................................................... 57
Figure 32: Effect of the char built up in the reactor for iron catalysts .......................................... 58
Figure 33: Effect of char built up in the reactor for nickel catalysts ............................................. 58
Figure 34: Conversion of known tar compounds-Effect of Temperature .................................... 59
Figure 35: Conversion tar - Effect of SV ...................................................................................... 59
Figure 36: Conversion of tar compounds- Effect of temperature ................................................ 60
Figure 37: Conversion of tar compounds –Effect of SV .............................................................. 61
Figure 38: Tar conversion for nickel based catalysts .................................................................. 62
Figure 39: Tar conversion for precious metal catalysts ............................................................... 62
Figure 40: Conversion of tar in an empty catalytic reactor .......................................................... 65