Biomass Gasification Overview Presentation)

National Renewable Energy Laboratory

Biomass Gasification Overview Presented by Richard L. Bain January 28, 2004 Operated for the U.S. Department of Energy by Midwest Research Institute • Battelle

Office of the Biomass Program Goals Reduce U.S. dependence upon foreign sources of petroleum Realization of the Industrial Biorefinery

Mission To foster research and development on advanced technologies to transform our abundant biomass resources into clean, affordable, and domestically-produced biofuels, biopower, and high-value bioproducts for improving the economic development and enhancing the energy supply options of the U.S.

The Unique Role of Biomass While the growing need for sustainable electric power can be met by other renewables…

Biomass is the only renewable that can meet our demand for carbon-based liquid fuels and chemicals

Research Focus for the Biorefinery Advanced Biomass R&D

Sugar Platform

Sugar Feedstocks

Residues

Biomass

Combined Heat & Power

Fuels, Chemicals, & Materials

Clean Gas

Thermochemical Platform

Systems Integration

Conditioned Gas

Integrated Industrial Biorefineries

Thermochemical Platform Costs for SynGas Intermediate Impact of Overcoming Technical Barriers 20 Reference: Hamelink and Faaij (2001)

18

Cost of Production ($/GJ)

16 14

Without Integrated Demonstrations

Pioneer Plant Costs

12 10 8 With Integrated Demonstrations

6 4 2 0 Base 550 tpd Nth plant

Feed Handling

Thermochemical Conversion

Gas Conditioning

Sensors & Controls

Process Integration

Performance Specific Program Goals Ye a r Minim um Synga s Se lling Price ($/GJ, LHV) Corre sponding H2 cost ($/kg) j product, e .g., m e tha nol ($/ga l) Fe e dstock cost ($/dry ton de live re d) Pla nt size (dry tons/da y)

2003

2005

2010

2015

2020

2025

2030

9

8.3

6

5.6

5.1

4.7

4.3

2.16

1.98

1.26

1.17

1.08

0.99

0.90

1.30

1.20

0.90

0.70

0.65

0.60

0.54

30

30

30

30

30

30

30

550

550

2,000

2,000

2,000

2,000

4,000

Feed Preparation/Gasification: 10% reduction in product cost by 2010 Gas Cleanup: 20% reduction in product cost by 2010 System Integration: 10% reduction in product cost by 2010

Strategic Fit

Biomass Thermochemical Conversion For Fuels and Chemicals

Biomass

Gasification

Cleanup

Pyrolysis

Conversion or Collection

Other Conversion *

Separation

Synthesis

PRODUCTS • Hydrogen • Alcohols • FT Gasoline • FT Diesel • Olefins • Oxochemicals • Ammonia • SNG

Purification

• Hydrogen • Olefins • Oils • Specialty Chem

Purification

• Hydrogen • Methane • Oils • Other

* Examples: Hydrothermal Processing, Liquefaction, Wet Gasification

Basic Definitions Biomass is plant matter such as trees, grasses, agricultural crops or other biological material. It can be used as a solid fuel, or converted into liquid or gaseous forms for the production of electric power, heat, chemicals, or fuels.

Black Liquor is the lignin-rich by-product of fiber extraction from wood in Kraft (or sulfate) pulping. The industry burns black liquor in Tomlinson boilers that 1) feed back-pressure steam turbines supplying process steam and electricity to mills, 2) recover pulping chemicals (sodium and sulfur compounds) for reuse.

Representative Biomass & Black Liquor Compositions Poplar

Corn Stover

Chicken Litter

Black Liquor

Proximate (w t% as rece ived) Ash Volatile Ma tter Fix ed Carbon Moisture

1.16 81.99 13.05 4.80

4.75 75.96 13.23 6.06

18.65 58.21 11.53 11.61

52.01 35.26 6.11 9.61

HHV, Dry (Btu/lb)

8382

7782

6310

4971

47.05 5.71 0.22 0.05 41.01 <0.01 1.16

43.98 5.39 0.62 0.10 39.10 0.25 4.75

32.00 5.48 6.64 0.96 34.45 1.14 19.33

32.12 2.85 0.24 4.79 0.71 0.07 51.91

1.20 --0.05 0.01 1.08 0.29 0.18 0.18

0.82 0.25 0.14 0.77 2.72 2.79 0.87 1.59 14

<0.01 0.05 <0.01 8.65 0.82 0.05 <0.01 <0.01

Ultimate, w t% as rece ive d Carbon Hydrogen Nitrogen Sulfur Oxygen (by diff) Chlorine Ash

Ele mental Ash Ana lysis, w t% of fuel a s re ceive d Si Fe Al Na K Ca Mg P As (ppm)

0.05 --0.02 0.02 0.04 0.39 0.08 0.08

Representative Biomass and Coal Properties

Biomass 1 Name Classification Proximate Analysis, wt% Dry Moisture Volatile Matter Fixed Carbon Ash Ultimate Analysis, wt % Dry C H N Cl O S Ash H/C Atomic Ratio HHV, Dry, Btu/lb

Wood

Biomass 2

Coal 1

Red Corn Cob Grundy, IL. No 4 HvBb

Coal 2

Tar Sands

Rosebud, MT sub B

Athabasca Bitumen

25-60 77-87 13-21 0.1-2

16 ca. 80 -4

8.16 40.6 45.47 13.93

19.84 39.02 49.08 9.16

50-53 5.8-7.0 0-0.3 .001-0.1 38-44 0-0.1 0.1-2

45 5.8 2.4 -42.5 0 4

68.58 4.61 1.18 0.12 6.79 4.76 13.93

68.39 4.64 0.99 0.02 16.01 0.79 9.16

1.4-1.6 8,530- 9,050

1.5 7,340

0.8 12,400

0.81 11,684

83.6 10.3 0.4 -0.2 5.5

1.47 17,900

Pyrolysis

Basic Definitions

Thermal conversion (destruction) of organics in the absence of oxygen • In the biomass community, this commonly refers to lower temperature thermal processes producing liquids as the primary product • Possibility of chemical and food byproducts •

Gasification • Thermal conversion of organic materials at elevated temperature and reducing conditions to produce primarily permanent gases, with char, water, and condensibles as minor products • Primary categories are partial oxidation and indirect heating

Thermochemical Conversion Of Biomass and Black Liquor

Product

Bio-Oil Changing World Technologies

High Pressure

Syngas Dry Ash

Gas Product: PNNL Wet Gasification (CH4/H2)

GTI (O2) Carbona (O2) HTW O2) Foster Wheeler (O2)

10-25 MPa

1- 3 MPa

Slag

Chemrec (O2) Noell

2 – 3 MPa

Feed: Biomass Feed: Biomass

Low Pressure 0.2 MPa

ENSYN Dynamotive BTG Fortum

Low (300-600°C)

MTCI-also Black Liquor FERCO (Indirect) MTCI (Indirect) Pearson (Indirect) TUV (Indirect) For CHP:TPS (Air) Carbona (Air) Lurgi (Air) Foster Wheeler (Air) EPI (Air) Prime Energy (Air)

Medium (700-850°C) Temperature

Feed: Black Liquor

Chemrec (Air)

High (900-1200°C)

Technical Barrier Areas Biomass Residues Dedicated Crops

Feed Processing & Handling

Gasification & Pyrolysis

Hydrogen & Bioproducts

Fuels & Chemicals

Export Electricity

Gas Conditioning & Separation

Syngas Utilization

Heat & Power Generation

Biorefinery Residues

™ ™ ™ ™ ™ ™ Critical Issues

Feed Processing and Handling Gasification / Conversion Gas Cleanup and Catalytic Conditioning Syngas Utilization Process Integration Process Control, Sensors, and Optimization

Biomass Thermochemical Conversion Primary Technical Barriers Gasification • Feed Pretreatment - Feeder reliability - Feed modification • Gasification - Tar & Heteroatom chemistry - Gasifier Design • Gas Cleanup & Conditioning - Catalytic Conversion - Condensing Cleanup - Non-condensing Cleanup • Syngas Utilization - Cleanliness requirements - Gas composition • Process Integration • Sensors and Controls

Pyrolysis • Oil Handling - Toxicity - Stability - Storage - Transportation • Oil Properties - Ash - Acidity • Oil Commercial Properties - Commercial Specifications - Use in Petroleum Refineries

Black Liquor Gasification • Containment - Metals - Refractories - Vessel design - Bed behavior/agglomeration • Mill Integration - Steam - Power - Causticizing • Fuels Chemistry - Carbon management - Tars - Sulfur management - Alkali management - Halogen management • Sensors and Controls

Representative Gasification Pathways Biomass

Feed Preparation & Handling

Low Pressure Gasification

Shift Conversion

Compression

Oxygen

High Pressure Gasification

Hot Gas Cleanup

Reforming

Compression

LP Indirect Gasification

Cold Gas Cleanup

Compression & Reforming

LP Indirect Gasification

Catalytic Conditioning & Reforming

Compression

CO2

Product

Acid Gas Removal

Synthesis

Biomass

Biomass Cyclone

Freeboard

Gas, Tar, Water

Gas, Tar, Water

Ash

Pyrolysis C + CO2 = 2CO C + H2O = CO + H2 C + O2 = CO2 4H + O2 = 2H2O

Pyrolysis

C + O2 = CO2 4H + O2 = 2H2O

Reduction

Fluid Bed

Combustion

C + CO2 = 2CO C + H2O = CO + H2

Combustion

Biomass

Reduction

Air

Plenum Air/Steam

Ash

Ash

Air

Fluid-Bed Gasifier

Downdraft Gasifier

Updraft Gasifier

Flue Gas

Secondary Cyclone

Primary Cyclone

Gasifier

Fly Ash

Char

Biomass Furnace

Biomass

Recycle Gas N2 or Steam Air/Steam

Air

Bottom Ash

Circulating Fluid-Bed Gasifier

Entrained Flow Gasifier

Community Power Corporation’s BioMax 15 Modular Biopower System

FERCO GASIFIER- BURLINGTON, VT 350 TPD

Carbona Project: Skive, Denmark TAR CRACKER GASIFIER

STACK GAS COOLER

BIOMASS

ASH

FUEL FEEDING

GAS COOLER GAS TANK

HEAT RECOVERY POWER AIR

HEAT GAS ENGINE(S)

ASH

Typical Gas Heating Values Gasifier

Inlet Gas

Product Gas Type

Product Gas HHV 3

MJ/Nm Partial Oxidation Partial Oxidation Indirect

Air Oxygen Steam

Producer Gas Synthesis Gas Synthesis Gas Natural Gas Methane

7 10 15 38 41

Gas composition versus reactor type Gas ifie r

FERCO

Carbona

Prince ton

IGT

M ode l Type

Indire ct CFB

Air FB

Indire ct FB

PFB

Age nt

s te am

air

s te am

O2/s te am

Be d M ate rial

olivine

s and

none

alum ina

w ood chips

w ood pe lle ts

black liquor

w ood chips

H2

26.2

21.70

29.4

19.1

CO

38.2

23.8

39.2

11.1

CO2

15.1

9.4

13.1

28.9

2

41.6

0.2

27.8

CH4

14.9

0.08

13.0

11.2

C2+

4

0.6

4.4

2.0

16.3

5.4

17.2

9.2

Fe e d Gas Com pos ition

N2

GCV , M J/Nm 3

Gas composition versus reactor type Gas ifie r

USEPA

IGT

Dow ndraft

Updraft

PFB

air

air

air

O2/s te am

s ilica

s ilica

none

none

alum ina

w ood chips

w ood chips

w ood chips

w ood chips

w ood chips

H2

31.5

9 - 11

16

10

19.12

CO

22.7

15 - 17

21.5

14.8

11.07

CO2

27.4

18

14.4

12.8

28.88

2.8

Diff

44.4

28.9

27.77

CH4

11.2

5-7

3.3

4.9

11.21

C2+

4

3

NA

NA

1.95

Type Age nt Be d M ate rial Fe e d

Te ch Univ

Fre e Univ

Univ of

V ie nna

of Brus s e ls

Zaragos a

Indire ct FB

Air FB

s te am

Gas Com pos ition

N2

Gasifier Types-Advantages and Disadvantages G asifier

A dvantages

D isadvantages

Updraft

M ature for heat Sm all scale applications Can handle high m oisture No carbon in ash

Feed size lim its High tar yields Scale lim itations Producer gas Slagging potential

Dow ndraft

Sm all scale applications Low particulates Low tar

Feed size lim its Scale lim itations Producer gas M oisture sensitive

Fluid Bed

Large scale applications Feed characteristics Direct/indirect heating Can produce syngas

M edium tar yield Higher particle loading

Circulating Fluid Bed

Large scale applications Feed characteristics Can produce syngas

M edium tar yield Higher particle loading

Entrained Flow

Can be scaled Potential for low tar Can produce syngas

Large am ount of carrier gas Higher particle loading Potentially high S/C Particle size lim its

Typical Gas, Contaminant Yields Hybrid Poplar 33.99 36.67 17.91 12.56 4.41 1.35 0.31 0.93 64-72 290 max

Switchgrass 24.31 39.47 14.97 13.77 5.86 0.96 0.20 0.62 323-396 760 max

Mixed Woods 31.82 31.59 17.96 11.73 4.50 1.06 0.24 1.01 36-63 339-369

-

0

486 max

4 max

+

10 max 2060 max 37

208 max 2320 max 1442-1472

7 max 2480 max ND

H2, vol % CO CO2 CH4 C2H4 Benzene Toluene H2/CO H2S, ppmv Ammonia, ppmv Cl cond, ppm-m/v K cond, ppm-m/v Tot org. C cond ppm-m/v Cyanide, ppm-m/v

Primary Processes Vapor Phase

CO, CO2, H2O

Light HCs, Aromatics, & Oxygenates

Primary Vapors

Tertiary Processes

Secondary Processes Olefins, Aromatics CO, H2, CO2, H2O

Low P Primary Liquids

Liquid Phase

High P

Condensed Oils (phenols, aromatics)

Low P Solid Phase

Biomass

High P

Charcoal

Coke

Pyrolysis Severity

Soot

PNA’s, CO, H2, CO2, H2O, CH4

CO, H2, CO2, H2O

Mixed Oxygenates 400

o

Phenolic Ethers

C

500

o

C

Alkyl Phenolics 600

o

C

Heterocyclic Ethers 700

o

C

Larger PAH

PAH 800

o

C

900

o

C

C o n v e n tio n a l F la s h P y r o ly s is (4 5 0 - 5 0 0 oC )

H i- T e m p e r a tu r e F la s h P y r o ly s is (6 0 0 - 6 5 0 oC )

C o n v e n tio n a l S te a m G a s ific a tio n (7 0 0 - 8 0 0 oC )

H i- T e m p e r a tu r e S te a m G a s ific a tio n (9 0 0 - 1 0 0 0 oC )

A c id s A ld e h y d e s K e to n e s F u ra n s A lc o h o ls C o m p le x O x y g e n a te s P h e n o ls G u a ia c o ls S y r in g o ls C o m p le x P h e n o ls

Benzenes P h e n o ls C a te c h o ls N a p h th a le n e s B ip h e n y ls P h e n a n th r e n e s B e n z o fu r a n s B e n z a ld e h y d e s

N a p h th a le n e s A c e n a p h th y le n e s F lu o r e n e s P h e n a n th r e n e s B e n z a ld e h y d e s P h e n o ls N a p h th o fu r a n s B e n z a n th r a c e n e s

N a p h th a le n e * A c e n a p h th y le n e P h e n a n th r e n e F lu o r a n th e n e P y re n e A c e p h e n a n th r y le n e B e n z a n th r a c e n e s B e n z o p y re n e s 226 M W PAH s 276 M W PAH s

* A t th e h ig h e s t s e v e r ity , n a p h th a le n e s s u c h a s m e th y l n a p h th a le n e a r e s tr ip p e d to s im p le n a p h th a le n e .

Chemical Components in biomass tars (Elliott, 1988)

Gasification Applications • Heat • District heating • Plant steam • Institutional heating • Combined heat and power • Pulp and paper industry • District heating/electricity • Electricity only • Cofiring - ash segregation • Integrated gasification combined cycle • Synthesis gas • Oxygenates - methanol, ethanol, DME, etc. • Fischer-Tropsch Liquids • Hydrogen • Methane • Chemicals

Biorefinery Utilities Applications

Synthesis Gas - Examples of Conversion Processes • Oxygenates • Methanol, DME, Mobil MTG • Mixed alcohols • Snamprogetti/Topsoe, Lurgi, Dow, IFP/Idemitsu • Modified Fischer Tropsch - ethanol • Dow, Pearson Technologies • Biochemical (fermentation) • Mississippi State University, University of Arkansas • Hydrocarbon fuels • Methane • Fischer Tropsch • Iron based - Sasol Synthoil • Cobalt based - Shell middle distillate synthesis (SMDS) • Hydrogen • Methane steam reforming • High and low temperature shift • H2 separation

Fe, Co, Ru

Rh

Ethanol

MTO MTG

se

sis

Aldehydes Alcohols

Methanol U ect Dir

, Co

H2

e th yn

) os 3 ) 4 (Bu Ox CO ) 3P 3) 3 o( CO Ph HC o( )(P HC h(CO R

(K2O, Al2O3, CaO)

zeolites

Cu/ZnO

hom Co ologa tion

3

ThO2 or ZrO2

H2O WGS Purify

NH3

Ag

Syngas CO + H2

Isosynthesis

N2 over Fe/FeO

Formaldehyde

Acetic Acid ca CH rbon yla 3O H Co + Ction ,R O h, Ni

Fischer-Tropsch

d l 2O pe /A do nO li3 /Z 3 ka r 2O Cu l 2O Al /C ; A O nO O/ Zn u/Z /Co C O Cu oS 2 M

i-C4

MTBE isobutylene acidic ion exchange

Mixed Alcohols

Olefins Gasoline

Al2O3

Waxes Diesel

DME M100 M85 DMFC

Olefins Gasoline

BIOMASS

FEED PREP

GASIFICATION

CLEANUP & CONDITIONING

Ethanol From Biomass

SYNGAS

BIOCONVERSION

Thermochemical Syngas – Biochemical Ethanol SEPARATION

ETHANOL

Fischer Tropsch Synthesis Low T FTS Slurry (Co) or Tubular (Fe) Reactor

Air, Oxygen, Steam

Coal, Natural Gas, or Biomass

Gasifier

Waxes (> C20) Hydrocracking

Gas Cleanup and Conditioning Particulate Removal Wet Scrubbing Catalytic Tar Conversion Sulfur Scrubbing WGS etc.

Clean syngas H 2 and CO

CFB or FFB(Fe) Reactor

High T FTS )1)

CO + 3H2 Æ CH4 + H2O (Methanation)

)2)

nCO + (2n+1)H2 Æ CnH2n+2 + nH2O (Paraffins)

)3)

nCO + 2nH2 Æ CnH2n + nH2O (Olefins)

)4)

nCO + 2nH2 Æ CnH2n+1OH + (n-1)H2O (Alcohols)

Diesel

Olefins (C3 - C11) Oligomerization Isomerization Hydrogenation

Gasoline

Simplified Methanol Synthesis Process Flow Diagram

Steam, O2 Natural Gas

Desulphurization

Steam Reforming BioSyngas

syngas (CO/CO2/H2) Compressor Purge Gas

Cooling and Distillation

Methanol Converter

syngas recycle loop CO + 2H2 Æ CH3OH

∆Hr = -90.64 kJ/mol

CO2 + 3H2 Æ CH3OH + H2O CO + H2O Æ CO2 + H2

∆Hr = -49.67 kJ/mol ∆Hr = -41.47 kJ/mol

Preferred Stoichiometry: (H2 – CO2)/(CO + CO2) = 2

Methanol

Heat and Power - Prime Movers Steam turbines Extracting - for CHP Non extracting - electricity only Small to large scale IC engines 5 kW to 2 MW Control of NOx and CO Turbines Microturbines Gas Turbines - GT and IGCC applications Stirling engines Fuel cells

Why Biomass + Fuel Cells? Good temperature and pressure match Attractive fuel gas characteristics Allows penetration of fuel cells into markets without natural gas distribution networks High efficiency maximizes biomass conversion to electricity - reduces biomass demand for energy production Fossil carbon substitution

Fuel Cells are "Reverse" Electrolysis

Fuel Cell Schematic Electrolyte (Ion conductor) Depleted fuel Out

Depleted Oxidant Out O2 +

PEMS

H2

H

PAFC

H2

H+

MCFC SOFC

H2 CO2 H2O H2 H2 O

H2O O2 H2O O2

CO3=

O=

80ºC 200ºC

650ºC

CO2 O2

Fuel In

1000ºC Oxidant In

Anode

Cathode

Cyclone

Gas Cleanup Product Gas

Freeboard

Exhaust Isothermal Pre-reformer

Ash

Compressor

Fluid Bed Biomass Plenum

Cooling Air

HRSG

Air/Steam

Fluid-Bed Gasifier

Carbonate Fuel Cells

A

C

Process Water A.C. Output

DC/AC Inverter Air Burner

Research and Development Areas (not all-inclusive)

• Feed characterization • Materials handling • Storage • Conveying • Moisture control • Comminution • Feeding • Gasification • Kinetics • Phase equilibria • CFD modeling • Gas cleanup • Tar, ammonia, water • Particulates, ash • Residual carbon control • Integrated process specific species • Gas separations • Process integration • Prime mover systems • Catalytic syngas conversion • Sensors and controls • LCA and TE modeling

NREL Facilities

MBMS

Engine Testing

Gasification (TCUF) TMBMS

Emissions Monitoring

Thermochemical Process Development Unit (TCPDU) ™Base Configuration Thermal Cracker

Biomass Feed

Blower Coalescing Filter

Scrubber

Hopper/Feeder

Wet scrubbed Syngas

Settling Tank Controller

8-in. Fluidized Bed Reactor Cyclones

Aqueous Effluent

Superheated Steam Char

TCPDU Process Conditions and Product Gas Composition TCPDU process parameters 11-Feb-03 to 28-Feb-03 steam feed rate (kg/h) 20.0 ± 0.2 biomass feed rate (kg/h) 10.5 ± 0.9 fluid bed T (ºC) 615 ± 1 thermal cracker T (ºC) 775 ± 2 product gas flow rate (kg/h) 8.2 ± 0.8 material balance 98.9±10% Averaged mass spectrum (TMBMS) of tars from indirect wood gasification 78

1e+5

8e+4

78 - benzene 91,92 - toluene 94 - phenol 104 - styrene 108 - cresol 116 - indene 128 - naphthalene

142 152 166 178 192 202 216

- methylnaphthalenes - acenaphthalene - flourene - anthracene/phenanthrene - methylanthracene? - pyrene/flouranthene - benzo(a)flourene

6e+4

128

91,92

4e+4

94

116

104 108

2e+4

142 152 166 178

192 202 216

0 75

100

125

150

175

200

Average gas composition from indirect wood gasification in TCPDU 2/11 to 2/28/03 GC analysis of Port 3 (vol. %, N2- and steam-free) hydrogen 26.9 ± 1.4 methane 15.6 ± 0.2 carbon monoxide 26.7 ± 1.4 carbon dioxide 23.5 ± 0.8 ethylene 4.1 ± 0.1 ethane 0.68 ± 0.07 acetylene 0.47 ± 0.04 propylene 0.32 ± 0.04 1-butene 0.16 ± 0.04 1.0 ± 0.1 H2/CO ratio Tar concentrations by TMBMS (ppmv, w/ steam and N2) benzene 1732 ± 165 toluene 715 ± 89 cresol 216 ± 44 naphthalene 327 ± 33 phenanthrene 72 ± 7

Experimental Approach 5 cm bench-scale reformer – March, 2001

30 cm pilot-scale reformer – April 2002 Gas Flow Rate

0.35-0.4 kg/hr

7-18 kg/hr

WHSV (weight of feed/hr / weight of catalyst) 1.6 hr-1

0.16-0.48 hr-1

Temperature 700-900°C

850°C

25000

CO

2

(/1 0 )

20000

Difference Mass Spectrum (catalyst outlet-inlet) showing destruction of biomass gasifier tars

15000

Intensity (arb.)

10000

5000

0

p y re n e

-5 0 0 0

to lu e n e

n a p h th a le n e

-1 0 0 0 0

-1 5 0 0 0

benzene -2 0 0 0 0 50

75

100

125

150

m /z

175

200

225

Project Status RFP issued

Response received

1/03

4/03

Revise scope to reduce cost; Contract placed

6/03 Tar Reformer

Cyclones

Expected Installation delivery complete

11/03 12/03 Scrubber

Catalyst testing

2/04-9/04

o

o

850 C

100

o

o

o

825 C

750 C

775 C

800 C

benzene

Methane and benzene breakthrough vs. time-on-stream for temperature ramp experiments with NREL-1 catalyst.

60

m ethane

40

20

0

0

1

2

3

4

5

6

7

tim e-on-stream (h)

105

o

o

850 C

825 C

o

o

o

750 C

775 C

800 C

2000

100

1500

90 1000

85

benzene slip (rt. axis)

500

80

0

75

0

1

2

3

4

time-on-srteam (h)

5

6

7

benzene slip (ppmv)

total tar

95

% conversion

% conversion

80

Total tar conversion and benzene slip for NREL-1Catalyst during temperature ramp experiments

NREL-1 Tem perature Ram p

100

% conversion

80 60

m ethane benzene toluene naphthalene phenan./anthr. cresol

40 20 0

750

775

800

825

850

2FBR tem perature ( o C) Steady State conversion of several tar species and methane for NREL-1 catalyst