has thermo-chemical conversion of wood a future ? by xavier deglise

13 November 200613 November 2006 IAWS Meeting 2006 XDIAWS Meeting 2006 XD 11

Has Thermo-chemical Conversion of Wood

a Future ?

by Xavier DEGLISE

Emeritus Professor at University Henri Poincaré, Nancy 1Emeritus Professor at University Henri Poincaré, Nancy 1

Has Thermo-chemical Conversion of Wood

a Future ?

by Xavier DEGLISE

Emeritus Professor at University Henri Poincaré, Nancy 1Emeritus Professor at University Henri Poincaré, Nancy 1

International Academy of Wood Science Meeting 2006


1. Introduction

2. Pyrolysis

3. Gasification

4. Carbonisation

5. Liquefaction

6. Conclusion


Forest Biomass represents 2230 MTOE/year (without deforestation) Forest Biomass represents 2230 MTOE/year (without deforestation) around 65% of 3365 MTOE in potential Renewable Energies. Biomass around 65% of 3365 MTOE in potential Renewable Energies. Biomass could fulfill 22 % of the actual world energy needs…and Wood is the could fulfill 22 % of the actual world energy needs…and Wood is the major biomass!major biomass!


But, there is a lot of issues for Forests!

1. Climate change

3. Nature oriented management

Forest owner behavior

Vulnerability

and extremes

2. Increased demand; incl. bio energy

New giants:

Russia, China

4. Forestry in broader context of all land uses

New services & functions: C sequestratio

n


Forests resources are increasing vs time!: C

sequestration

-0,030

0,020

0,070

0,120

0,170

1950 1955 1960 1965 1970 1975 1980 1985 1990 1995

Co

mp

on

en

ts o

f th

e t

ota

l fo

res

t s

ec

tor

sin

k (

Pg

C y

-1)

Tree Biomass

Coarse woody debris

Forest floor

Mineral soil

Wood Products

Total

European forest sector carbon balance 1950 –1999 (Nabuurs et al. 2003) Pg C y-1= Petagram C / year =1015 gram / year


In EU 25, still fellings remain rather stable, In EU 25, still fellings remain rather stable, and the resource is growing fast!and the resource is growing fast!

0

100

200

300

400

500

600

700

800

1950 1960 1970 1980 1990 2000

Net annual increment

Fellings

Mil. m3 over bark

Latest German inventory gave a net

annual increment of 12 m3.ha-1.y-1


““Bio energy” will lead to anBio energy” will lead to an extra extra

demanddemand

Value added will be very low

…but the stove needs to burn

Current oil price rise

~ 100 $ /ton CO2 carbon tax

Suitability of residue extraction

from EU 25 forests


Extra Resource Wood Biomass ?Extra Resource Wood Biomass ?


Source of Residue Type of Residue Forest operations Branches, needles, leaves, stumps,

roots, low grade and decayed wood, slashings and sawdust

Pulp industry, Sawmilling and planning

Bark, sawdust, trimmings, split wood, planer shavings

Plywood production Bark, core, sawdust, veneer clippings and waste, panel trim, sanderdust

Particleboard production

Bark, screening fines, panel trim, sawdust, sanderdust

Wood Wastes Packing material, old wooden furniture, wooden building waste (demolition wood)

Wood ResiduesWood Residues


Estimated potential of Wood ResiduesEstimated potential of Wood Residuesin the Worldin the World

Overall quantity of WR * Overall quantity of WR * ~~ 2,000 MT/y or 2,000 MT/y or ~~ 650 MTOE/y to compare with 650 MTOE/y to compare with

7,000 MT/y of Forest biomass or 2 230 7,000 MT/y of Forest biomass or 2 230 MTOE/yMTOE/y

WR WR ~ 30% of potential Forest Biomass~ 30% of potential Forest Biomass

* Matti Parikka, Biomass and Bioenergy 27 (2004) 613–620


Wood Residues vs “Clean Wood”Wood Residues vs “Clean Wood”in Francein France

Overall quantity of WR: 16 MT / year to compare Overall quantity of WR: 16 MT / year to compare withwith

o ~ ~ 23 MT / Year of processed wood (5 MT/y imported) 23 MT / Year of processed wood (5 MT/y imported)

o ~ ~ 40 MT / Year of Wood biologically produced by the 40 MT / Year of Wood biologically produced by the forestforest

o ~ ~ 20 MT / Year of Fuel Wood (estimated) with 80% 20 MT / Year of Fuel Wood (estimated) with 80% domestic consumptiondomestic consumption

WR represent an important source of Biomass (5.5 WR represent an important source of Biomass (5.5 MTOE)…but is scattered!MTOE)…but is scattered!

WR corresponds only to 6% of the oil consumption WR corresponds only to 6% of the oil consumption (96 MT/y)(96 MT/y)


Biomass upgrading into Energy or Chemicals

Co-combustion

Bioprocesses

Fuel cells

EngineTurbine

SNGDMEH2

Fischer Tropschhydrocarbons

Alcohols

Methanol

Ethanol

Bio-fuel

DirectCombustion

Biomass

ElectricityHeat

GasificationPyrolysis

DirectLiquefaction

N/A ?

N/A ?


Overview of “Wood thermal Processes”Overview of “Wood thermal Processes”

(Co) combustion GasificationPyrolysis

Wood

Upgrading treatment

CH3OH, CnHm, H2

Direct heating

IndirectHeating

Synthesis/cleaning

Atmospheric or pressurizedO2, air, H2O

Bio-fuels

Direct Liquefaction

syngas

H2O, critical conditions,Hydro liquefaction (H2)

High Pressure

Liquid biomassHeavy bio-oil

slowfast, flash

Heat and Electricity

Flue gas

Engine or Turbine

charoilgas

Charcoal


Operating conditions of the thermal Operating conditions of the thermal processesprocesses

Thermal Process

Temperature Atmosphere Products Mean overall Yield

Combustion > 900°C O2 (air) CO2 + H2O + N2

+ ashes to be treated~ 65 %

Pyrolysis < 500°C Inert gas orLow

pressure

char + tars + gas, which proportions are related to the pyrolysis parameters

~ 45 %

Gasification by Fast

pyrolysis

> 700°C Inert gas orLow

pressure

Mainly gas (CO, H2, CH4, C2H4 …) with low quantity

of char used

~ 75 %

Gasification > 800°C Air or H2O vapour

Gas (H2, CO, CO2, CH4, N2) + ashes to be treated

50-60 %

Liquefaction by Fast

Pyrolysis

< 550°C Low pressure

High viscosity liquid (phenols)

~ 75 %

Direct Liquefaction

300°C- 350°CSlurry in water

CO High pressure

High viscosity liquid (phenols) non soluble in

water

~ 80 %


1. Introduction

2. Pyrolysis

3. Gasification

4. Carbonisation

5. Liquefaction

6. Conclusion


Pyrolysis is the Key Reaction of Pyrolysis is the Key Reaction of allall the thermal Processes the thermal Processes

Pyrolysis

Gasification Liquefaction Charcoal makingCombustion Heated Wood

WOOD

Cutting or Grinding

Drying


Mechanism of the pyrolysisMechanism of the pyrolysis

HO LO C ELLULO SE

high T

depolymerization

high T

depolymerization

LIG NIN

fragmentation,decarbonylation(C O),dehydration(H 2O)

transglicos ilation

low T

low T

C har, H 2O,C O, C O 2

C har, C O , CO 2

ac ids, acetol,furfural, lac tons,hydroxyacetaldehyde

levoglucosan and sugars

phenols ,methoxyphenols(guaiacols),dimethoxyphenols(syringols)

C arbonylcompounds,furans, phenols ,C O, C O 2

Primary degradation Sec ondary degradation

Sec ondary degradation

Sec ondary degradation


Operating conditions of the pyrolysis Operating conditions of the pyrolysis processprocess

PAH


To lower the PAH’sTo lower the PAH’s

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!


1. Introduction

2. Pyrolysis

3. Gasification

4. Carbonisation

5. Liquefaction

6. Conclusion


Possible applications of the Product Possible applications of the Product

GasGas co-combustion in a coal power plant co-combustion in a coal power plant co-combustion in a natural gas power plant without co-combustion in a natural gas power plant without

modifications at the burners modifications at the burners production of electric energy in a gas turbine production of electric energy in a gas turbine production of electric energy in a gas engine production of electric energy in a gas engine production of electric energy in a fuel cell production of electric energy in a fuel cell as synthesis gas in the chemical industry as synthesis gas in the chemical industry as reduction gas in the steel industry as reduction gas in the steel industry for direct reduction of iron ore for direct reduction of iron ore for production of Synthetic Natural Gas by for production of Synthetic Natural Gas by

methanation methanation for production of Liquid Fuels by Fischer-Tropsch for production of Liquid Fuels by Fischer-Tropsch


Main ReactionsMain Reactions Wood (Pyrolysis) C slightly endothermicWood (Pyrolysis) C slightly endothermic

C + OC + O22 CO CO22 ( (ΔΔHH00= -391,6 kJ mol-1) exothermic= -391,6 kJ mol-1) exothermic

C + HC + H22O O CO+H CO+H22 ( (ΔΔHH00 = + 131,79 kJ mol-1) endothermic = + 131,79 kJ mol-1) endothermic

C + COC + CO22 2 CO ( 2 CO (ΔΔHH00 = + 179,3 kJ mol-1) endothermic = + 179,3 kJ mol-1) endothermic

CO + HCO + H22O O CO CO22 + H + H2 2 ((ΔΔHH00 = - 47,49 kJ mol-1) slightly = - 47,49 kJ mol-1) slightly exothermic exothermic

C + 2HC + 2H22 CH CH44 ( (ΔΔHH00= - 22 kJ mol-1) slightly exothermic = - 22 kJ mol-1) slightly exothermic

With the operating parameters (Pressure, Temperature) it is With the operating parameters (Pressure, Temperature) it is possible to select a gas containing more Syngas (CO+Hpossible to select a gas containing more Syngas (CO+H22) or ) or more SNG (CHmore SNG (CH44))


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 < energy in put!

Problems with Tars!

0 5 10 15 20

vapeur/ catalyseur

vapeur/ olivine

vapeur/ quartz

air/ quartz

Tar content (g/Nm3 dry gas) in the fuel gas

Güssing

EC project

Circulating Fluidized Bed

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 compact……not 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 < energy input!

Circulating Fluidized Beds

Example: FERCO (Battelle)

Numerous systems have been developedsince 1980:- KUNII- FERCO- Our (TNEE)- RENET (Güssing)- ………….


We have an old expertise in wood gasification in dual fluidized bed pyrolysis, until the pilot scaleA pilot with a capacity of 500Kg/H pine barks was operating in a pulp mill in 1984/1985.Its power was around 2 MWand it produces a medium BTU Gas (HHV around 16000 KJ/m3)

bois

gaz de pyrolyse recyclé (300 - 400°C)

lit en pyrolyse( ~ 800°C)

char + caloporteur

lit transporté de combustion(950°C)

caloporteur (950°C)

fumées (950°C)

cyclone dépoussièreur

gaz de pyrolyse(850°C)

20 Years later….always the same process developed in the RENET Biomass Power Station, Güssing, Austria (Schematic layout)

Photos of the RENET Pilot which start in Austria in 2001

Circulating Fluidized Bed with CO2 Absorber


Complete Syngas Complete Syngas ProcessProcess

GasifierCombustor

Heat Exchangers

Steam Dried Biomass

Air

Water treatment &steam production unit

Fly Ashremoval

Bottom AshExtraction

Catalyst heat

carrier

ShiftReactor

Wet scrubber

SynthesisGas

Gas compression

Flue Gas CO2

elimination


Pressurised fl uidised

Bed

Circulating Fluidised

Bed

Fluidised Bed

Downdraf t

Updraf t

1 MW 10 MW 100 MW 1000 MW1 kW 10 kW 100 kW

0,2 kg/ h 2 kg/ h 20 kg/ h 200 kg/ h 2 t/ h 20 t/ h 200 t/ h

Optimum Capacity of Gasification Processes

10t/h could be a great maximum for RW


To solve the problem of capacity, it is necessary To solve the problem of capacity, it is necessary to have a pre-treatment process producing a to have a pre-treatment process producing a char from different kinds of biomass, which char from different kinds of biomass, which could be then transformed at a larger scale.could be then transformed at a larger scale.

Such a system is proposed for the production of Such a system is proposed for the production of Hydrogen from BiomassHydrogen from Biomass

The Philosophy of this two step process could be The Philosophy of this two step process could be adapted, as the optimum input feed of the adapted, as the optimum input feed of the gasification must be over 10T/Hgasification must be over 10T/H


1. Introduction

2. Pyrolysis

3. Gasification

4. Carbonisation

5. Liquefaction

6. Conclusion


cellulose

00,2 0,4 0,6

rapport O/C0,8

pétroles

rapport H/C

1,5asphaltesbitumes

charbons

1000 °C (26,5 %)800 °C (26,7 %)

600 °C ( 31 %)

500 °C (33 %)

400 °C (37,8 %)

300 °C (51,4 %)

200 °C (91,8 %)

(rendement de production en % de la masse anhydre)

lignine

230 °C1

0,5

bois

charbons

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


Low temperature Pyrolysis for Wood Low temperature Pyrolysis for Wood Residues Residues “The Chartherm Process”“The Chartherm Process”


1. Introduction

2. Pyrolysis

3. Gasification

4. Carbonisation

5. Liquefaction

6. Conclusion


1. Introduction

2. Pyrolysis

3. Gasification

4. Carbonisation

5. Liquefaction

6. Conclusion

Liquid fuels from Syngas

Liquid fuels from Pyrolysis


For hydrocarbons the main Reactionof Fischer Tropsch Synthesis:

n CO + (m/2 +n) H2 = CnHm + nH20Catalyst (metal oxides)

This process is used in RSA, its name is SASOL, producing around 15 Mio T/y of liquid fuel

The relative proportion of CO and H2 vary as a function of what you want: gas or diesel

With Syngas we can produce Hydrocarbons or Methanol

CO+2H2 = CH3OH

For methanol the main reaction is:

energy efficiency from tree-to-barrel: 44%light products: 11%, power: 14%

overall energetic efficiency: about 69%

Biomass-derived Fischer-Tropsch diesel production

Stepwise gasification to bio-diesel production


1. Introduction

2. Pyrolysis

3. Gasification

4. Carbonisation

5. Liquefaction

6. Conclusion

Liquid fuels from Syngas

Liquid fuels from Pyrolysis


Wood Liquefaction via Fast Pyrolysis


Wood Liquefaction via Fast Pyrolysis

Bubbling fluid bed reactor with electrostatic precipitator

Circulating fluid bed reactor


Wood Liquefaction via Fast PyrolysisProduct Yield vs temperature


Bio-oil from fast Pyrolysis The crude pyrolysis liquid or bio-oil is dark brown

and approximates to biomass in elemental composition.

Ready substitution for conventional fuels in many stationary applications such as boilers, engines, turbines

Heating value of 17 MJ/kg at 25% wt. water, is about 40% that of fuel oil / diesel

Does not mix with hydrocarbon fuels

Not as stable as fossil fuels


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, CO+H2O = CO2+H2) in water at elevated temperatures (300-350°C) with sufficient pressure to maintain the water primarily in the liquid phase (12-20 MPa) for residence times up to 30 minutes.


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.


1. Introduction

2. Pyrolysis

3. Gasification

4. Carbonisation

5. Liquefaction

6. Conclusion


Actually, all the thermo-chemical processes are Actually, all the thermo-chemical processes are not able to convert wood into liquid fuels.not able to convert wood into liquid fuels.

The main problems are:The main problems are:

Capacity of the plant in relationship with the Capacity of the plant in relationship with the input feedinput feed

How to use different sources of dry biomass How to use different sources of dry biomass (residues from forest and wood industries, (residues from forest and wood industries, treated wood, wastes…)treated wood, wastes…)

What to do with the by-products of the different What to do with the by-products of the different steps of the conversions (gas, liquid or solid)steps of the conversions (gas, liquid or solid)

Energy efficiencyEnergy efficiency


Idea ?Idea ?

CharcoalTreated Wood wastes

Untreated Wood WastesPrimary Processing

Recovered wood from Forest Operations

Thinnings….

Dry urban WastesPaper, cardboard

Charcoal

Charcoal

Charcoal

Gasification

CO + H2

SNG

Methanol

Bio-diesel (FT)

Hydrocarbons(FT)

Pyrolysis


Questions?Questions?

has thermo-chemical conversion of wood a future ? by xavier deglise

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