Title: Gasification and Pyrolysis
1International 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
3Forest 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!
4But, there is a lot of issues for Forests!
3. Nature oriented management
Vulnerability and extremes
1. Climate change
2. Increased demand incl. bio energy
5Forests 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
6In 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
7Bio 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
8Extra Resource Wood Biomass ?
9Wood Residues
10Estimated 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)
12Biomass 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 ?
13Overview 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
14Operating conditions of the thermal processes
15- Introduction
- Pyrolysis
- Gasification
- Carbonisation
- Liquefaction
- Conclusion
16Pyrolysis is the Key Reaction of all the thermal
Processes
WOOD
Cutting or Grinding
Drying
17 Mechanism of the pyrolysis
18Operating conditions of the pyrolysis process
PAH
19To 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
21Possible 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
22Main 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)
23Main 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!
24Problems with Tars!
25Circulating Fluidized Bed
26Advantages 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!
27Circulating Fluidized Beds
Numerous systems have been developed since
1980 - KUNII - FERCO - Our (TNEE) - RENET
(Güssing) - .
Example FERCO (Battelle)
28We 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(No Transcript)
3020 Years later.always the same process developed
in the RENET Biomass Power Station, Güssing,
Austria (Schematic layout)
31Photos of the RENET Pilot which start in Austria
in 2001
32Circulating Fluidized Bed with CO2 Absorber
33Complete 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
34Optimum 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
37Van 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
38Low 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
42With 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
43Biomass-derived Fischer-Tropsch diesel production
- energy efficiency from tree-to-barrel 44light
products 11, power 14overall energetic
efficiency about 69
44Stepwise 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
55Idea ?
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
56Questions?