BIO-SYNGAS GENERATION

BIO-SYNGAS GENERATION

A. van der Drift, H. Boerrigter, R. ZwartECN-biomass, Petten, the Netherlands

2 International Conference on IGCC & XtL Technologies, Freiberg, 16 June 2005

CONSIDERATIONS

- typical syngas processes are 100 MW (chemical sector), >100 MW (gas- and electricity sector), and >1000 MW (transportation fuels)

- 50% of the biomass globally available (i.e. technical potential) is woody material; 20-40% is grassy

- so: focus on woody and grassy biomass (different pre-treatment) in large bio-syngas plants

- (bio-)syngas contains H2 and CO (and CO2 and H2O), but no or little N2, CH4, etc…

- thermodynamics: temperature needs to be 700 - 1000°C, but kinetics need 1300°C…

biomass bio-syngas


GASIFIER CHOICE

biomass

high T: >1300°C(EF: entrained flow)

low T: <1000°C(catalytic)

slagging

non-slagging

new: not existingnot fuel flexible2 steps; expensive

not robustnot fuel flexible

+ flux + recycle


SLAGGING ENTRAINED FLOW GASIFIER

• high temperature (typically 1300-1500°C)• pure oxygen• wall protected by liquid melt: slag • pressurized (20-50 bar)• short residence times (1-2 seconds)• small fuel particles needed (100 µm,

might be 1 mm for biomass)• high conversion

[Future Energy, Freiberg]


ASH MELTING (1)

clean wood deposit from LCS lab-scale facility, 1400°C [ECN-report: ECN-C-04-039]


ASH MELTING (2)

thermodynamic calculations, clean wood

0%

20%

40%

60%

80%

100%

800 1000 1200 1400 1600 1800

T [°C]

slag

as

wt%

of f

uel a

sh (

incl

. flu

x, e

xcl

gas

phas

e)

Silica/fuel ash =0.25 kg/kg



Silica/alumina/fuelash = 0.5/0.45 kg/kg

Original clean wood


ASH MELTING (3)

thermodynamic calculations, clean wood, 1300°C, flux added Ca/Si/Al = 1/1/1, average 12% solid, 81% liquid,7% gas

0%

20%

40%

60%

80%

100%

Ca Si Al K Mg P Na Mn Fe Pb Zn

wt%

gas liquid solid


BIOMASS FEEDING

biomassfeeding

conventional

like coal(100 µm)

direct

torrefaction

slurry

dedicatedlow temperature gasifier

1 mm

flash pyrolysis


TORREFACTION

[ECN-report: ECN-C-05-013]

0

20

40

60

80

100

0.0 0.2 0.4 0.6 0.8 1.0 1.2

average particle size after pulverisation [mm]

pow

er c

onsu

mpt

ion

[kW

e/M

Wth

]

wood

torrefied wood


SYSTEM ASSESSMENT (1)

FROM clean wood “there”TO Fischer-Tropsch diesel “here”

pre-treatment options:• direct milling• torrefaction + milling• flash pyrolysis• low-T gasification

transportation/import options:• wood chips• wood pellets• pyrolysis oil/char slurry• torrefied wood pellets• Fischer-Tropsch crude

η? €?


SYSTEM ASSESSMENT (2)BCF ROTTERDAMHUB

FT-synthesisEF

1300°C40 bar

Pulverizing

FT-synthesisEF

1300°C40 bar

PyrolysisPulverizing

FT-synthesisEF

1300°C40 bar

PulverizingTorrefaction

FT-synthesisEF

1300°C40 bar

CFB

FT-synthesisEF

1300°C40 bar

Grinding

FT-synthesisEF

1300°C40 bar

PyrolysisGrinding

FT-synthesisEF

1300°C40 bar

Pulverizing

FT-synthesisEF

1300°C40 bar

FT-synthesisEF

1300°C40 bar

Grinding

Chips

Chips

Chips

Chips

Pellets

Pellets

Pellets

Slurry

Pellets

FT-Crude

Chips

Chips

Chips

Chips

Pellets

Pellets

Pellets

Slurry

Pellets

Chips

PelletizingPulverizingTorrefactionDryingChipping

FT-synthesisEF

1300°C40 bar

PulverizingTorrefactionGrinding

DryingChipping

PyrolysisDryingChipping Pulverizing

PelletizingDryingChipping

DryingChipping PelletizingPulverizing

DryingChipping PelletizingPulverizing

DryingChipping

DryingChipping

DryingChipping

DryingChippingC1

C2

C3

C4

C5

C6

C7

C8

C9

C10

C1

C2

C3

C4

C5

C6

C7

C8

C9

C10


SYSTEM ASSESSMENT (3)

0 500 1000 1500 2000 2500 3000 3500

C1

C2

C3

C4

C5

C6

C7

C8

C9

C10

Cas

e

Absolute annual costs [M€/yr]

0.0 2.2 4.4 6.6 8.8 11.0 13.2 15.4

79%

69%

72%

77%

79%

69%

72%

69%

72%

79%

Absolute costs [€/GJsyngas]

Biomass costs

Transhipment costs

Transportation costs

Storage costs

Capital costs

O&M costs

Utility, by- and restproduct costs

wood pellet transport

Fischer-Tropsch products transport

torrefied wood pellet crude transport

pyrolysis oil/char slurry transport

wood chips transport


TRAJECTORY (1)from now to large-scale biosyngas plants

time

inst

alle

d ca

paci

ty [M

W]


upscaling, starting with present CHP plants

biomass replaces coal: modification of existing

large-scale coal gasification technology


TRAJECTORY (2)

starting point: coal dry-feed gasification technology

replacing coal with biomass, main R&DD issues:- biomass pre-treatment and feeding- burner design and gasification- ash and slag behavior- hot gas treatment



CONCLUSIONS

- bio-syngas generation should preferably take place in a slagging entrained flow gasifier:- maximum analogy with existing large-scale coal gasification- fuel flexible- quick implementation

- slagging behavior of pure biomass ash is poor, Si/Al flux seems good option

- torrefaction turns biomass into “coal”, it may play a crucial role in short-term large-scale bio-syngas generation

- transport crucial in final syngas costs, high energy density needed: (torrefied) wood pellets, oil/char-slurry or FT-products


EPILOGUE

IGCC and XtL

X = biomasst = toL = SNG (Substitute Natural Gas)


MORE INFORMATION

Bram van der Drift or Harold Boerrigtere: [email protected] or [email protected]: +31 224 56 4515 or 4591PO Box 1NL 1755 ZG Pettenthe Netherlands

Publications can be found on: www.ecn.nl/biomass

“Phyllis” - internet database for biomass, coal, and residues: www.phyllis.nl

Documents

BIO-SYNGAS GENERATION