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Gasification and Pyrolysis

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Forest Biomass represents 2230 MTOE/year (without deforestation) around 65% of ... Naphtalene, Anthracene, Pyrene, Benzopyrene . – PowerPoint PPT presentation

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Title: Gasification and Pyrolysis


1
International Academy of Wood Science Meeting 2006
Has Thermo-chemical Conversion of Wood a Future
? by Xavier DEGLISE Emeritus Professor at
University Henri Poincaré, Nancy 1
2
  • Introduction
  • Pyrolysis
  • Gasification
  • Carbonisation
  • Liquefaction
  • Conclusion

3
Forest Biomass represents 2230 MTOE/year (without
deforestation) around 65 of 3365 MTOE in
potential Renewable Energies. Biomass could
fulfill 22 of the actual world energy needsand
Wood is the major biomass!
4
But, there is a lot of issues for Forests!
3. Nature oriented management
Vulnerability and extremes
1. Climate change
2. Increased demand incl. bio energy
5
Forests resources are increasing vs time! C
sequestration
European forest sector carbon balance 1950 1999
(Nabuurs et al. 2003) Pg C y-1 Petagram C / year
1015 gram / year
6
In EU 25, still fellings remain rather stable,
and the resource is growing fast!
Latest German inventory gave a net annual
increment of 12 m3.ha-1.y-1
7
Bio energy will lead to an extra demand
Current oil price rise 100 /ton CO2 carbon
tax
Value added will be very low but the stove
needs to burn
Suitability of residue extraction from EU 25
forests
8
Extra Resource Wood Biomass ?
9
Wood Residues
10
Estimated potential of Wood Residuesin the World
  • Overall quantity of WR 2,000 MT/y or 650
    MTOE/y to compare with
  • 7,000 MT/y of Forest biomass or 2 230 MTOE/y
  • WR 30 of potential Forest Biomass

Matti Parikka, Biomass and Bioenergy 27 (2004)
613620
11
Wood Residues vs Clean Woodin France
  • Overall quantity of WR 16 MT / year to compare
    with
  • 23 MT / Year of processed wood (5 MT/y
    imported)
  • 40 MT / Year of Wood biologically produced by
    the forest
  • 20 MT / Year of Fuel Wood (estimated) with 80
    domestic consumption
  • WR represent an important source of Biomass (5.5
    MTOE)but is scattered!
  • WR corresponds only to 6 of the oil consumption
    (96 MT/y)

12
Biomass upgrading into Energy or Chemicals

Co-combustion
Electricity Heat
Biomass
Direct Combustion
Fuel cells
SNG DME H2 Fischer Tropsch hydrocarbons Alcohol
s Methanol Ethanol Bio-fuel
Engine Turbine
Gasification
Pyrolysis
Direct Liquefaction
N/A ?
Bioprocesses
N/A ?
13
Overview of Wood thermal Processes
Wood
(Co) combustion
Gasification
Pyrolysis
Direct Liquefaction
slow fast, flash
Atmospheric or pressurized O2, air, H2O
H2O, critical conditions, Hydro liquefaction
(H2) High Pressure
Direct heating
Indirect Heating
Flue gas
char oil gas
Liquid biomass Heavy bio-oil
syngas
Upgrading treatment
Synthesis/cleaning
Engine or Turbine
Bio-fuels
Charcoal
Heat and Electricity
CH3OH, CnHm, H2
14
Operating conditions of the thermal processes
15
  • Introduction
  • Pyrolysis
  • Gasification
  • Carbonisation
  • Liquefaction
  • Conclusion

16
Pyrolysis is the Key Reaction of all the thermal
Processes
WOOD
Cutting or Grinding
Drying
17
Mechanism of the pyrolysis
18
Operating conditions of the pyrolysis process
PAH
19
To lower the PAHs
  • Naphtalene, Anthracene, Pyrene, Benzopyrene
    which are formed during the pyrolysis step of the
    thermal conversion, it is compulsory
  • to decrease the Residence Time
  • to increase the Temperature
  • when it is possible!

20
  • Introduction
  • Pyrolysis
  • Gasification
  • Carbonisation
  • Liquefaction
  • Conclusion

21
Possible applications of the Product Gas
  • co-combustion in a coal power plant
  • co-combustion in a natural gas power plant
    without modifications at the burners
  • production of electric energy in a gas turbine
  • production of electric energy in a gas engine
  • production of electric energy in a fuel cell
  • as synthesis gas in the chemical industry
  • as reduction gas in the steel industry
  • for direct reduction of iron ore
  • for production of Synthetic Natural Gas by
    methanation
  • for production of Liquid Fuels by Fischer-Tropsch

22
Main Reactions
  • Wood (Pyrolysis) C slightly endothermic
  • C O2 ? CO2 (?H0 -391,6 kJ mol-1) exothermic
  • C H2O ? COH2 (?H0 131,79 kJ mol-1)
    endothermic
  • C CO2 ? 2 CO (?H0 179,3 kJ mol-1)
    endothermic
  • CO H2O ? CO2 H2 (?H0 - 47,49 kJ mol-1)
    slightly exothermic
  • C 2H2 ? CH4 (?H0 - 22 kJ mol-1) slightly
    exothermic
  • With the operating parameters (Pressure,
    Temperature) it is possible to select a gas
    containing more Syngas (COH2) or more SNG (CH4)

23
Main kinds of Reactors for Gasification
Updraft and Downdraft reactors have been
developed since 1930. They produce a low BTU
Gas ( 6000 KJ/m3) with tars. Actually the new
systems use mainly fluidized beds and circulating
fluidized beds.but they are often too
complicated energy output lt energy in put!
24
Problems with Tars!
25
Circulating Fluidized Bed
26
Advantages of Gasification by fast Pyrolysis in
a Circulating Fluidized Bed System
  • product gas nearly free of nitrogen
  • calorific value higher than 13 MJ/Nm³
  • very low tar content due to steam gasification
  • gas quality is independent of water content in
    biomass feed
  • now, the apparatus are compactnot enough!
  • a wide range of feedstock can be gasified
  • possibility to use a catalyst as bed material
    (regeneration of catalyst in combustion zone) to
    influence the gas composition and gasification
    kinetic in a more positive way
  • But sometimes energy output lt energy input!

27
Circulating Fluidized Beds
Numerous systems have been developed since
1980 - KUNII - FERCO - Our (TNEE) - RENET
(Güssing) - .
Example FERCO (Battelle)
28
We have an old expertise in wood gasification in
dual fluidized bed pyrolysis, until the pilot
scale A pilot with a capacity of 500Kg/H pine
barks was operating in a pulp mill in
1984/1985. Its power was around 2 MW and it
produces a medium BTU Gas (HHV around 16000 KJ/m3)
29
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30
20 Years later.always the same process developed
in the RENET Biomass Power Station, Güssing,
Austria (Schematic layout)
31
Photos of the RENET Pilot which start in Austria
in 2001
32
Circulating Fluidized Bed with CO2 Absorber
33
Complete Syngas Process
Flue Gas
Fly Ash removal
Shift Reactor
Wet scrubber
CO2 elimination
Heat Exchangers
Gas compression
Gasifier
Combustor
Catalyst heat carrier
Water treatment steam production unit
Synthesis Gas
Bottom Ash Extraction
Air
Dried Biomass
Steam
34
Optimum Capacity of Gasification Processes
10t/h could be a great maximum for RW
35
  • To solve the problem of capacity, it is necessary
    to have a pre-treatment process producing a char
    from different kinds of biomass, which could be
    then transformed at a larger scale.
  • Such a system is proposed for the production of
    Hydrogen from Biomass
  • The Philosophy of this two step process could be
    adapted, as the optimum input feed of the
    gasification must be over 10T/H

36
  • Introduction
  • Pyrolysis
  • Gasification
  • Carbonisation
  • Liquefaction
  • Conclusion

37
Van KREVELEN Diagram giving the elementary
Composition and yield of Charcoal vs
carbonization temperature It is possible to
select which kind of Char you want high
Carbon content high Yield .. Porosity
depends on the heating Rate
38
Low temperature Pyrolysis for Wood Residues The
Chartherm Process

39
(No Transcript)
40
  • Introduction
  • Pyrolysis
  • Gasification
  • Carbonisation
  • Liquefaction
  • Conclusion

41
  • Introduction
  • Pyrolysis
  • Gasification
  • Carbonisation
  • Liquefaction
  • Conclusion

Liquid fuels from Syngas
Liquid fuels from Pyrolysis
42
With Syngas we can produce Hydrocarbons or
Methanol
For hydrocarbons the main Reaction of Fischer
Tropsch Synthesis
n CO (m/2 n) H2 CnHm nH20
Catalyst (metal oxides)
The relative proportion of CO and H2 vary as a
function of what you want gas or diesel
This process is used in RSA, its name is SASOL,
producing around 15 Mio T/y of liquid fuel
For methanol the main reaction is
CO2H2 CH3OH
43
Biomass-derived Fischer-Tropsch diesel production
  • energy efficiency from tree-to-barrel 44light
    products 11, power 14overall energetic
    efficiency about 69

44
Stepwise gasification to bio-diesel production
45
  • Introduction
  • Pyrolysis
  • Gasification
  • Carbonisation
  • Liquefaction
  • Conclusion

Liquid fuels from Syngas
Liquid fuels from Pyrolysis
46
Wood Liquefaction via Fast Pyrolysis

47
Wood Liquefaction via Fast Pyrolysis

Bubbling fluid bed reactor with electrostatic
precipitator
Circulating fluid bed reactor
48
Wood Liquefaction via Fast PyrolysisProduct
Yield vs temperature

49
Bio-oil from fast Pyrolysis

50
  • Direct Hydrothermal Liquefaction
  • Direct hydrothermal liquefaction involves
    converting Wood to an oily liquid (crude oil), in
    a pressurized reactor with CO
  • The reaction was
  • CO wood product CO2 reduced wood
  • Wood react with CO, (in fact H2 coming from a
    shift reaction, COH2O CO2H2) in water at
    elevated temperatures (300-350C) with sufficient
    pressure to maintain the water primarily in the
    liquid phase (12-20 MPa) for residence times up
    to 30 minutes.


51
  • Direct Hydrothermal Liquefaction (continued)
  • The overall approx. stoichiometry is
  • 100 Kg wood 1 mol CO 2.2 mol CO2 1 mol H2O
    55 Kg of non vapor product.
  • oil yield was 33 of dry wood feed with a rather
    high energy content, giving a high energy yield,
    around 65 of the HHV of wood.
  • Hydrothermal treatment is based on early work
    performed by the Bureau of Mines Albany
    Laboratory in the 1970s.


52

53
  • Introduction
  • Pyrolysis
  • Gasification
  • Carbonisation
  • Liquefaction
  • Conclusion

54
  • Actually, all the thermo-chemical processes are
    not able to convert wood into liquid fuels.
  • The main problems are
  • Capacity of the plant in relationship with the
    input feed
  • How to use different sources of dry biomass
    (residues from forest and wood industries,
    treated wood, wastes)
  • What to do with the by-products of the different
    steps of the conversions (gas, liquid or solid)
  • Energy efficiency

55
Idea ?
Charcoal
Treated Wood wastes
SNG
Untreated Wood Wastes Primary Processing
Charcoal
Methanol
Gasification CO H2
Recovered wood from Forest Operations Thinnings.
Charcoal
Bio-diesel (FT)
Hydrocarbons (FT)
Charcoal
Dry urban Wastes Paper, cardboard
Pyrolysis
56
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