gasification of biomass lecture no. 7 - strona główna...

Gasification of biomass

Lecture no. L3-1

Dr hab. inż. Marek Ściążko

Prof. nadzw.

Copyright-MS-2013 1

Technologies and products of thermo-chemical

biomass conversion

Combustion

Pyrolysis

Gasification

Heat

Gas

Bio-oilstorage

Turbine

Engine

Boiler

Chemicals

Fuels

Hydrogen

Power

Heat

PROCESS MARKETCONVERSIONPRODUCT

Copyright-MS-2013 2

Potential Biomass Gasifier

Feedstocks

Copyright-MS-2013 3

Gasifier Classification

Copyright-MS-2013 4

BIOMASS GASIFICATION TECHNOLOGIES

Pyrolysis

Gasification

Combustion

Ash

Air

Gas

C + CO2 = 2CO

C + H2O = CO + H

2

C + O2 = CO

2

4H + O2 = 2H

2O

Pyrolysis

Combustion

Gasification

Ash

C + O2 = CO2

4H + O2 = 2H2O

C + CO2 = 2CO

C + H2O = CO + H

2

BiomassBiomass

gas

Air

Biomass

Air

Steam

Gas

Ash

Cyclone

CycloneCyclone

Ash

Biomass

Air

Steam

Ash

COUNTER CURRENT/

UPDRAFT

CO-CURRENT/

DOWNDRAFT

BUBBLING FLUIDISED BED (BFB) CIRCULATING FLUIDISED BED (CFB)

Copyright-MS-2013 5

BIOMASA

POPIÓŁ POWIETRZE

GAZ BIOMASA

POPIÓŁ

POWIETRZE

GAZ

A) B)

SUSZENIE

ZGAZOWANIE

PIROLIZA

UTLENIANIE

SUSZENIE

PIROLIZA

ZGAZOWANIE

UTLENIANIE

Fixed bed biomass gasiefiers

Ash Air Ash Gas

Biomass Gas Biomass

Air

Drying

Pyrolysis

Combustion

Gasification

Drying

Pyrolysis

Gasification

Combustion

Copyright-MS-2013 6

Fluid bed reactors features

Ideal radial gas mixing Ideal radial and axial gas mixing

Biomass

Process gas

Oxygen (Air)

Steam

Copyright-MS-2013 7

Gasification steps

Copyright-MS-2013 8

Gasification reactions

Copyright-MS-2013 9

Evaluation of reactors’

characteristics PARAMETERS

Up-draft Down-draft Cross flow Bubbling Circulating

Reaction temperature [C] 1000 1000 900 850 850

Gas temperature [C] 250 800 900 800 850

Throughput [t/h] 10 0.5 1 10 50

Electric power [MWe] 1 - 10 0.1 - 5 0.1 - 2 1 - 20 2 - 100

Tars content v. high v. low v. high medium low

Particulates av. high medium high v. high v. high

Mixing intensity low low low good v. good

Limits for particle size some some some specific specific

Moisture content any limited limited limited limited

Fuel flexibility no effect low effect low effect strong strong

Scaling up limited low low good v. good

Process control medium medium low v. good v. good

Conversion efficiency v. good v. good low good v. good

Thermal efficiency v. good v. good good good v. good

DEVELOPMENT POTENTIAL

EFFECTIVITY

FIXED BED FLUID BED

GAS CHARACTERISTIC

FEEDSTOCK REQUIRAMENTS

Copyright-MS-2013 10

Syngas Contaminants


GASIFIER CHARACTERISTICS

• P.Quaak, H.Knoef, H.Stassen, ENERGY FROM BIOMASS, A Review of Combustion and Gasification Technologies; World Bank Technical Paper No. 422, Energy Series, 1999

• H.E.M. Stassen, H.A.M. Knoef, SMALL SCALE GASIFICATION SYSTEMS, Biomass Technology Group BV, The Netherlands

• P. Hasler*, Th. Nussbaumer, GAS CLEANING FOR IC ENGINE APPLICATIONS FROM FIXED BED BIOMASS GASIFICATION, Biomass and Bioenergy 16 (1999) 385±395

• A.V. Bridgwater, Fuel 1995, 74 (5), 631.

Parameter Downdraft Updraft CFB

Fuel

-moisture content (%)

-ash content (%, daf)

-size (mm)

< 25

<6

20-100

< 60

<25

5-100

< 25

<25

<20

Gas

- temperature (oC)

- LHV (kJ/mn3)

- tar content (g/ mn3)

- particulates (g/

mn3)

- composition (%

v/v.)

H2

CO

CO2

CH4

800

4-6

0,01-6

0,1-8

15-21

10-22

11-13

1-5

200-400

4-6

10-150

0,1-3

10-14

15-20

8-10

2-3

850

5-6,5

2-30

8-100

15-22

13-15

13-15

2-4

Max commercial capacity

(forecast) (MWth) 1 10 100

Scale-up ability poor good v. good


Composition of biomass derived

syngas


Technology: fixed bed, updraft reactor

Power: 2,5-3,5 MWt

Fuel: Waste Biomass granulation: > 300 mm

Gasification agent: Air

1 – gas generator

2 - lock

3 – transport and feeding system

4 – ash removing system

5 – gas pipeline

6 – air installations

7 - burner

Pilot scale tests

EKOD gasification reactor - construction and process description


Pilot scale tests Stand for gasification tests

Gasifier

Boiler

se

pa

rato

r

Fuel

(biomass)Gas

Aircombustion

gases

AshDust

P - pressure

T - temperature

V - flow

A - composition

Air

Ash

1

V

1

A

3

A

3

P

3

T

3

V

2

P

2

T

2

V 4

P

4

T

4

V

5

V

3

A

6

P

6

T

3

V


Pilot scale tests Fuel characteristics

Feedstock Form of

the fuel

LHV,

MJ/kg

Volatile

matter

% w/w,

Ash

% w/w

Moisture

% w/w

Ultimate analysis,

% w/w.

C H O N

Waste wood

Irregular

fuel

pieces up

to 30 cm

17,6 79,6 0,4 7,5 48,7 5,9 37,4 0,1

Wood chips

Wood

chips 3-5

cm

16,1 71,9 0,4 15 44,1 5,2 35,3 0,05

Fiber and chipboard

Irregular

fuel

pieces up

to 30 cm

15,6 69,0 0,5 15 42,9 5 35,8 0,8

Tyres / wood mixture

Irregular

fuel

pieces up

to 30 cm

25,6 68,2 2,7 8 63,1 4,8 20,5 0,1


Pilot scale tests Results: gasification reactor

Feedstock

t, Fuel flow

rate

Air/fuel

ratio

Gas flow

rate (dry)

Gas LHV

(dry)

Cold gas

efficiency

oC kg/h kg/kg mn3/kgfuel kJ/mn

3 %

Waste wood 760 490 2,1 2,5 5660 80

Wood chips 685 580 1,9 2,3 5200 75

Fiber and chipboard 685 680 1,8 2,2 4770 68

Tyres / wood mixture 690 360 2,1 2,4 9250 86

Feedsto

ck

Gaseous compounds, % v/v(dry) Dus

t,

mg/

mn3

Tar,

mg/

mn3 H2

N2 +

O2 CO

CH

4

CO

2

C2

H4

Other

s*

Waste

wood 7,4 59,3

18,

9 4,4 8,6 1,1 0,3

105

5 643

Wood

chips 6,8 59,1

17,

3 3,7

11,

8 0,9 0,4 350 406

Fiber

and

chipboa

rd

6,2 60,9 16,

7 2,8 12 1,0 0,4

197

0

293

4

Tyres /

wood

mixture 3,0 58,0

20,

0 3,5 8,0 6,5 1,0

287

0

121

0


Gas composition


Pilot scale tests Results: gasification reactor- boiler

pollutant

Feedstock

Emission

Standard Waste wood

Wood

chips

Fiber and

chipboard

Tyres / wood

mixture

CO, mg/mn3 76 341 338 50 -

SO2, mg/mn3

Bellow

detection

level

39 173 293 400

NO2, mg/mn3 209 212 625 341,3 400

Pył, mg/mn3 54 58 230 284 100


Pilot scale tests Results: comparison with literature

0

5

10

15

20

25

LHV

(MJ/Nm3)

Tar (g/Nm3) particulates

(g/Nm3)

H2 (% vol.) CO (% vol.) CO2 (% vol.) CH4 (% vol.)

co-current

counter current

Ecod

Ecod (biomass)

150


Simulation of the process

0

10

20

30

40

50

60

0,5 1,0 1,5 2,0 2,5

Vp/mpal [mn3/kg]

%o

bj.

H2

CH4

CO

CO2

O2

N2

H2O

A)

0

10

20

30

40

50

60

0,5 1,0 1,5 2,0 2,5

Vp/mpal [mn3/kg]

%o

bj

H2

CH4

CO

CO2

O2

N2

B)

Free Gibbs enthalpy minimization.

Composition of generated gas:

CO, CO2, O2, H2, CH4, H20, N2.

Temperature of the process: 750oC

Feedstock properties: waste wood

Chemcad software (Chemstations Inc.)

16,2

3,2

18,5

8,47,4

59,3

53,8

4,4

18,9

8,6

4700

4712

0

10

20

30

40

50

60

70

80

H2 CH4 CO CO2 N2+O2 LHV

compound

% v

ol

0

1000

2000

3000

4000

5000

6000

LH

V,

kJ/m

3

calculation

experiment

LHV, calculation

LHV, experiments


Raw wood Wood chips

Wood cutter

Start up: 2005

WOOG CHIPS GASIFICATION – 5 MWth

PELLETS


Wood chips gasification

Current state

Furniture production plant Holzwerk,

Drygały Poland (waste wood)

Lubuski Tannery Plant, Leszno Górne,

Poland (tanning wastes)

Enpal (Słubice, Poland) – wood chips

ICPC, ZAMER, Modern Technologies

and Filtration

drying installation of wood waste for the

pellets production

Parameter Unit value

Gasification agent - air

Thermal output MWth 3 - 5

Gas temperature oC <800

Fuel (wood chips)

Water kontent

LHV

granulation %

GJ/Mg

mm

< 20

> 14

6-40


Gasifier

Combustion chamber

Process gas

Air

Wood chips Flue

gas

Fuel: Wood chips

Moisture content:

20%

LHV: 14 GJ/Mg

Capacity:

1500 kg/godz

THERMAL CAPACITY 5 MWt


Process instrumentation and

control template


Visualization of gasifier

performance


Gas combustion chamber


Coal – biomass co-firing systems

Indirect co-firing

High flexibility in arranging and integrating

the main components into existing plants

Now pretreatment of biomass is needed –

low gas quality is sufficient for co-firing

Gas could be fed to the boiler without

cooling and cleaning

No slag formation in the boiler (most

important issue in case of direct co-firing)

Favorable effects on power plant

emissions (CO2 - biomass, NOx -

reburning effect)

No severe modifications of the existing

coal fired boiler

biomass

BOILER

B)

BIOMASS

PULVERIZER

C)

BOILERgas

D)

GASIFICATION REACTOR

BOILER

BOILER

COMBUSTION

CHAMBER

flue gases

A)

BIOMASSbiomass

• T. Nussbaumer, Combustion and co-combustion of biomass, “12th Conference and Technology Exhibition on Biomass for Energy, Industry and

Climate Protection”, Amsterdam, 2002.

• G. Moritz, J. Tauschitz, Mitverbrennung von Biomasse in Kohlekraftwerken. Conference „Bois-Energie, Mulhouse, France, 2001

• Energetische Nutzung biogener (Ersatz-)Brennstoffe durch Vergasung und emissionsoptimierte Einspeisung mittels Gasfeuerung in (Dampf-)

Kesselanlagen und Ofenprozessen. Konzeptpapier, Fraunhofer-Institut für Umwelt-, Sicherheits- und Energietechnik UMSICHT, November 2002.

• A. Mory, J. Tauschitz, Holz Energie 1999, 4, 37.


Future development

Small scale CHP systems

Contami

nant Examples Problems Cleanup method

Particula

tes Ash

Erosion,

emission

Filtration,

scrubbing

Tars Refractory

aromatics

Clog filters,

deposit

internally,

Tar cracking, tar

removal

Alkali

metals

Sodium and

potassium

compounds

Hot

corrosion

Condensation,

adsorbtion,

filtration

Sulfur,

chlorine H2S, HCl

Corrosion,

emission

Scrubbing,

absorption

biomass

Gasification Gas cleaning Power and heat production

• Tars

• Particulates

• Alkali metals

• Sulfur, chlorine


Max concentration

of CO for FC – 100 ppm

IMURITIES CONTENT [g/m3]

REQUIRAMENTS

Ash 1.33

Nitrogen (NH3+HCN) 0.47

Sulphur (H2S+COS) 0.01

Alkalis 0.1

Chlorine (HCl) 0.1

Tars 0.15

Heavy metals 0

GAS QUALITY REQU. BOILER ENGINE GT

LHV [MJ/m3] X >4 >4

Particulates [mg/m3] X 5 - 50 5 - 7

Tars [mg/m3] X < 0.5 <0.1

Alkali metals [ppm] X 1 - 2 0.2 - 1

Gas quality required


CAT

CAT QUE

EXTERNAL

THERMAL

CRACKING

EXTERNAL

CATALYTIC

CRACKING

INTERNAL

CATALYTIC

CRACKING

PHYSICAL TAR

SEPARATION

INTERNAL

THERMAL

CRACKING

ULTRA-HIGH TEMPERATURE

GASIFICATION

Biomass

Process gas

Oxygen (Air)

Steam

Waste water

Gas treatment methods


ELECTRICAL

POWER

SNG

H2

METHANOL

MOTOR FUELS

TE

CH

NO

LO

GY

OP

TIO

NS

Plant capacity

1 MM t/a

6 MM t/a

700 MM $

2000 MM $

Technology options dilemma

-scale effect


Indirect biomass gasification –

prospect for efficient hydrogen

production

FLUID BED

COMBUSTION

PYROLYSIS

SHC+CFBR

Air

CONVERSION

GAS CLEANING

Tlen

Ch

ar

+S

HC

Heat

Biomss

BLOCK DIAGRAM - BIOMASS

PYROLYSIS WITH SOLID HEAT

CARRIER FOR SYNTHESIS GAS

DRYING

Process gas

SOLID HEAT

CARRIER

SEPARATION

Heat carrier

Acronym:

PYROSYN

Oxygen


Summary EKOD fixed bed gasifier is characterized by relatively high conversion

efficiency. Depending on used feedstock, the efficiency was in range

68-86 % (cold gas efficiency).

Produced gas was characterized by relatively high calorific value

(4800 – 9200 kJ/mn3) and low tar content (400 – 3000 mg/mn3).

Operation experiences confirm the flexibility and reliability of the

construction and readiness for commercial applications particularly

for heat generation in stand alone boilers or in existing co-fired units.

Possible further development direction comprises small scale CHP. It

needs to develop tars free gasification systems. This option gives the

opportunity for broad application in heat and power generation

industry.

Biomass gasification and related syngas production for chemical

synthesis or hydrogen production still needs new technology options.


gasification of biomass lecture no. 7 - strona główna...

Documents