Biomass – Thermal Conversion

Niko DeMartini, Tooran Khazraie

Cellulosic

Biomass Pyrolysis etc.

SynGas

(CO+H2)

Fischer-Tropsch

Methanol

Water-Gas Shift

Dehydroxygenation

Zeolite Upgrading

Bio-oils

Aqueous

Sugars

Lignin

Fermentation

Dehydration

Aq.-Phase Processing

Lignin Upgrading

Liquid Fuels

Alkanes

Methanol, DME

Hydrogen

Ethanol

Aromatic

Hydrocarbons

Liq. Alkanes or H2

Etherified Gasoline

Combustion Heat & Power Heat & Power

Conversion Routes for Cellulosic Biomasses

Biorefinery - Application of Chemical

Engineering Principles

Thermal Conversion

Pyrolysis

+O2 / H2O,

λ<1, hv Gasification

Combustion

Torrefaction

Solid

Bio

ma

ss

240 to

300 °C

400 to

600 °C

650 to

1100 °C

900 to

1300 °C

+O2, λ>1

hv, No O2

hv, No O2

Cellulosic

Biomass Pyrolysis etc.

SynGas

(CO+H2)

Fischer-Tropsch

Methanol

Water-Gas Shift

Dehydroxygenation

Zeolite Upgrading

Bio-oils

Aqueous

Sugars

Lignin

Fermentation

Dehydration

Aq.-Phase Processing

Lignin Upgrading

Liquid Fuels

Alkanes

Methanol, DME

Hydrogen

Ethanol

Aromatic

Hydrocarbons

Liq. Alkanes or H2

Etherified Gasoline

Combustion Heat & Power Heat & Power

Conversion Routes for Cellulosic Biomasses

Biorefinery - Application of Chemical

Engineering Principles

Solid fuel

Ash

Drying

Pyrolysis/

devolatilisation

and

gas combustion

Char

combustion

Combustion of a solid fuel

O2

O2

CxHyOz

CO2

+H2O

CO/CO2

H2O

Air

200

400

600

800

Te

mp

era

ture

(°C

)

0

20

40

60

80

100

We

igh

t (%

)

0 50 100 150 200 250

Time (min)

Sample: Birch, 1) 100% N2, 2) 20% O2 + N2Size: 9.1080 mg

Synthetic air

(20% O2 + 80% N2)

Drying

Pyrolysis

Char-C oxidation Only N2

Solid fuel

Ash

Drying

Pyrolysis/

devolatilisation

and

gas combustion

Char

combustion

O2

O2

CxHyOz

CO2

+H2O

CO/CO2

H2O

Air

Endothermal

Exothermal

Exothermal

RXN: endo-/exothermal

Process: endothermal

Energy release during combustion

Cellulosic

Biomass Pyrolysis etc.

SynGas

(CO+H2)

Fischer-Tropsch

Methanol

Water-Gas Shift

Dehydroxygenation

Zeolite Upgrading

Bio-oils

Aqueous

Sugars

Lignin

Fermentation

Dehydration

Aq.-Phase Processing

Lignin Upgrading

Liquid Fuels

Alkanes

Methanol, DME

Hydrogen

Ethanol

Aromatic

Hydrocarbons

Liq. Alkanes or H2

Etherified Gasoline

Combustion Heat & Power Heat & Power

Conversion Routes for Cellulosic Biomasses

Biorefinery - Application of Chemical

Engineering Principles

Pyrolysis

Torrefaction

Solid

Bio

ma

ss

240 to

300 °C

400 to

600 °C

650 to

1100 °C

900 to

1300 °C

hv, No O2

hv, No O2

(DeMartini) (Khazraie)

Thermal Conversion

Torrefaction

Volatiles H2O,

CO2,Acetic

Acid,tars,

CO, H2, CH4

Biomass

Volatiles

Torrefaction

Temp.: 240 – 300 °C

~30-60 min

Biomass

Combustion

Heat

Torrefaction Demonstration

Plants - WPAC November

2012 11

Andritz ACB Process, Austria (1 t/h)

Torrefaction of biomass

(Andritz)

Benefits Improved storage properties

Higher energy density possible

Reduced water uptake

Reduced biological decay

Improved grindability Can use same grinders as for coal

Lower energy consumption during grinding

Smaller particles after grinding

Co-combustion with pulverized coal (?)

Thermal Conversion

Pyrolysis

Torrefaction

Solid

Bio

ma

ss

240 to

300 °C

400 to

600 °C

650 to

1100 °C

900 to

1300 °C

hv, No O2

hv, No O2

(Khazraie)

Metso supplies a bio-oil production plant to

Fortum Joensuu power plant in Finland

Demonstration plant will produce bio-oil

from forest residue

• Bio-oil capacity 30 MW

• Annual production 50 000 t, 210 GWh

• Forest residue usage 225 000 solid-m3/year

Bio-oil production technology

Metso DNA automation system High pressure steam Turbine

Electricity

Non-condensible gas

District heat

Condenser Crusher

Drying

Sand and

coke 500 ºC

Sand

800 ºC

Forest residue

Fluidized bed boiler Pyrolyzer Bio-oil

Bio-oil characteristics

Heating value (LHV) 13-18 MJ/kg,

i.e. about half of LHV of heavy fuel

oil

Water content 20-35 weight-%

Viscosity between that of light and

heavy fuel oil

Acidic, pH 2-3

Density about 1.2 kg/l

Immiscible with mineral oils

Can be used instead of heavy fuel

oil

In the future also as raw material for

chemical industry or for biodiesel

production

0

10

20

30

40

50

60

70

80

90

100

Bio-oil W

eig

ht-

%

Aldehydes, ketones

Acids

'Sugars'

Water

Extractives

Lignin

Fossil oil

Fossil hydrocarbons

Thermal Conversion

Pyrolysis

+O2 / H2O,

λ<1, hv Gasification

Combustion

Torrefaction

Solid

Bio

ma

ss

240 to

300 °C

400 to

600 °C

650 to

1100 °C

900 to

1300 °C

+O2, λ>1

hv, No O2

hv, No O2

What Happens in a Gasifier?

Char

Pyrolysis

Volatiles,

tars

Droplet/particle Solids

Drying

Moisture

Ash

Char gasification

O2, CO2, H2O

H2, CO

(M. Hupa)

200

400

600

800

Te

mp

era

ture

(°C

)

0

20

40

60

80

100

We

igh

t (%

)

0 50 100 150 200 250

Time (min)

Sample: Birch, 1) 100% N2, 2) 20% O2 + N2Size: 9.1080 mg

Synthetic air

(20% O2 + 80% N2)

Drying

Pyrolysis

Char-C oxidation Only N2

What would happen if we

use CO2 + N2

instead of synt. air?

200

400

600

800

Te

mp

era

ture

(°C

)

0

20

40

60

80

100

We

igh

t (%

)

0 50 100 150 200 250 300

Time (min)

Sample: Birch, 1) 100% N2, 2) 20% N2 + 80% CO2Size: 8.4260 mg

(80% CO2 + 20% N2)

Drying

Pyrolysis

Char-C oxidation Only N2

C(s) + CO2 → 2 CO

(endothermic)

What Happens in a Gasifier?

Char

Pyrolysis

Volatiles,

tars

Droplet Solids

Drying

Moisture

Ash

Char gasification

O2, CO2, H2O

H2, CO

Product gas / Syn Gas

(M. Hupa)

Gasification Concepts

I. Combustion of the product gas

II.Combustion of the product gas in a gas engine

III.Gasification to liquid fuels / synthetic natural gas

CFB Gasifier

850 °C

900 °C

BOTTOM ASH COOLING SCREW

HOT LOW CALORIFIC GAS (750 - 650 °C)

UNIFLOW CYCLONE

FUEL FEED

REACTOR

BOTTOM ASH

GASIFICATION AIR FAN

COOLING WATER

AIR PREHEATER

RE

TU

RN

LE

G

Foster Wheeler

BIOMASS GASIFICATION - COAL BOILER - LAHTI PROJECT

Bottomash

Gasifier

Coal

540 °C/170 bar

Processing

Biomass

Fly ash

Pulverized coal flames

Gas flame

Natural Gas

50 MW

300 GWh/a -15 % fuel input

1050 GWh/a -50 %

350 MW

650 GWh/a -35 %

Power

* 600 GWh/a

District Heat

* 1000 GWh/a

CO2 Reduction -

10 %

Foster Wheeler

Metsä Fibre, Joutseno lime kiln

CFB-gasification process

Wood biomass 22 t/h (58 % MC)

Max. evaporation 12 t/h

Hot water and steam from mill

12 MW

Nominal heat flow 48 MW

750 – 800 C / 7 kg/s

Fuel

receiving

Belt Dryer

Fuel feeding silo

Bed material feeding silo

CFB gasifier

Burner

Lime kiln

Fuel to gasifier

11 t/h (15 % MC)

(Andritz)

Biomass/Waste Gasification, Gas Cleaning and Gas Burning (Lahti Energia, Lahti, Finland)

2.

Gas cooling and cleaning

Gas combustion boiler 121 bar, 540 °C

(Metso Power)

Fuel Treatment 250 000 t/y SRF

Fluidzed bed gasifier

Gasification and Gas Burning vs Direct Combustion 160 MWth Fuel Feed

Palonen et al., 2008

Gasification Concepts

I. Combustion of the product gas

II.Combustion of the product gas in a gas engine

III.Gasification to liquid fuels / synthetic natural gas

Biomass gasification to liquid fuels

Fischer-Tropsch process:

CO + 2H2 → (CH2) + H2O

(2n+1)H2 + nCO → CnH(2n+2) + nH2O

Cellulosic

Biomass Pyrolysis etc.

SynGas

(CO+H2)

Fischer-Tropsch

Methanol

Water-Gas Shift

Dehydroxygenation

Zeolite Upgrading

Bio-oils

Aqueous

Sugars

Lignin

Fermentation

Dehydration

Aq.-Phase Processing

Lignin Upgrading

Liquid Fuels

Alkanes

Methanol, DME

Hydrogen

Ethanol

Aromatic

Hydrocarbons

Liq. Alkanes or H2

Etherified Gasoline

Combustion Heat & Power Heat & Power

Conversion Routes for Cellulosic Biomasses

Biorefinery - Application of Chemical

Engineering Principles