Research on the reforming of ethanol - Bioenergy LAMNET · Research on the reforming of ethanol Seite 2 Reforming of Ethanol, LAMNET-Workshop, Brasilia Introduction - regenerative

Dr.-Ing. Peter Hübner

LAMNET Workshop, Brasilia, Dec. 2 - 4, 2002

Research on the reforming of ethanol

Seite 2

Reforming of Ethanol, LAMNET-Workshop, Brasilia

Introduction

- regenerative energy sources for hydrogen fuel cells- motivation for ethanol as fuel

Reforming of fossil fuels- allothermal reforming- partial oxidation- autothermal reforming

European Project: bioethanol reforming- reformer and shift conversion device- burner development- catalyst screening

Summary, Outlook

CH3CH2OH

H2O

H2-rich gas

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Introduction regenerative energy sources for hydrogen fuel cells

1. Electrolysis of water with electricityfrom regenerative sources like

- windenergy- hydropower- solar energy

regenerative power sources:

until now neglegiblemarket penetration

2. Reforming of biogenic (CO2-neutral) fuels- solid biomass (wood, wood pellets)- biogas- pyrolysis oil- biogenic ethanol

bio-ethanol - can be reformed

most „easily“

- is economically attractive(see following slides)

⇒motivation for ethanol

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Introduction: motivation for ethanol as fuel - economic potential

Preliminary estimation of worldwide market penetration:

550 million tons per year in the transport sector (20 % of present consumption)

500 million tons per year for co-generation capacity (10 % of present capacity)

several hundred million tons per year in the domestic market

200 million tons per year for the chemicals market

Source: Guiliano Grassi, “Bioethanol - Industrial world perspectives” in Renewable Energy World, May-June 2000, p. 86 - 97

potential contribution of ethanol to energy supply is significant

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100

62,950

31,425

15,7

0

20

40

60

80

100

1980 1990 2000

cost in $/barrelcost in EUROC/ l

Cost reduction potential: the Brazilian example

Source: José Goldberg in “Tagungsband zur Veranstaltung Biotreibstoffe”, 22. Juni 1999, Rüschlikon, Switzerland

1 Barrel = 159 literassumption: 1 Dollar = 1 Euro

Introduction: Motivation for ethanol as fuel

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allothermal reforming

heat is transferred via a burner,special burner design required

high hydrogen content of thereformate

convectiveheat transfer

Radiative burner

Reforming reactor

400

600

800

1000

1200

Reformer

Off-gas

Off-gas burner

Temperature/ °C

Reaction path

H2 75-78 Vol %CO2 10-12 Vol %CO 8-10 Vol %CH4 2- 5 Vol %H2O

25 % C of HC75 % H2 O

Reforming of fossil fuels

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partial oxidation

2

HCO2N 2

CO2 (0,6-2 Vol%)CO (14-18 Vol%)CH4 (0 Vol%)N2 (43-52 Vol%)

O

H2 (24-30 Vol%)Reforming reactor

400

800

1200

Reaction path

Temperature / °C

1600

H

without catalyst at 1300 °C - 1400 °C

good dynamic behaviour

simple construction

lowest hydrogen content

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autothermal reforming

heat is released in thecatalyst bed

quick start-up

good dynamic behaviour

temperature peak atthe reactor inlet

HCO2N2H2O

CO2 (8-10 Vol%)CO (9-11 Vol%)CH4 (0,2-4 Vol%)N2 (48-52 Vol%)H2O

H2 (28-32 Vol%)Reforming reactor

400

600

800

1000

1200Temperature / °C

Reaction path

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steam reforming of alcohols,general equation CnH2n+1OH + (2n -1) H2O ⇔ 3n H2 + n CO2

steam reforming of ethanol C2H5OH + 3H2O ⇔ 6 H2 + 2 CO2 ∆RH = 173,5 kJ/mol

endothermal cracking of ethanol C2H5OH + H2O ⇔ 4 H2 + 2 CO ∆RH = 255,9 kJ/mol

exothermal CO-conversion CO + H2O ⇔ H2 + CO2 ∆RH = -41,2 kJ/mol

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Partnership:

Fraunhofer ISE Reforming of bioethanol,CO-conversionCo-ordinat ion

Universt ity of Duisburg Fine purif icat ion by PSA

Nuvera Fuel cell requirements,implementat ion and disseminat ion of the results

Bioethanol as fuel for fuel cell vehicles and small scale stationaryapplications JOR3-CT97-0174

Summary of results: May, 2001

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European project: bioethanol reforming

Reformer- PEM fuel cellsystem with ethanol as fuel

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Reformer und CO-conversion device at Fraunhofer ISE

1

2

34

5

1. Water/ethanol pump

2. Reformer

3. HT-shift reactor

4. NT-shift reactor

5. Gas cooling heat exchanger

European project: bioethanol reforming

Reformer700 - 1000°C

HT-shift350-400°C

NT-shift180-220°C

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Experimental set-up:

Reformer:

Height: 150 mm

Diameter: 121 mm

Catalyst Volume: 600 cm3

Burner:

Height: 150 mm

Diameter: 81 mm

European project:bioethanol reforming

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European project: advantages of the porous burner bioethanol reforming

high effective heat conduction of the pore material( 60 - 100 higher then the effective heat conduction of gas)

⇒ large combustion reaction zone( flame burner reaction zone thickness 1 mm)

⇒ lower temperature in the reaction zone⇒ homogeneous temperature profile⇒ lower NOx- and CO-emission

high flame velocity in the pore medium without flame instability( 8 - 10 higher then a flame burner)

⇒ large performance modulation range 1:20 ( flame combustion 1:3)

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European project: catalyst screeningbioethanol reforming

name composition sign. operation rangenickel-cat. nickel on Al2O3 Ni treact ion < 800ruthenium-cat. ruthenium on Al2O3 Ru treact ion < 800platinum –cat. platinum on Al2O3 Pt treact ion < 800palladium –cat. palladium on Al2O3 Pd treact ion < 800Perovskite-cat. lanthanum, manganese, cobalt, strontium Pe treact ion < 800nickel-platinum-cat. nickel; platinum on Al2O3 PtNi treact ion < 800nickel-palladium-cat. nickel; palladium on Al2O3 NiPd treakt ion < 800

investigation parametersTemperature: 600; 700; 800 °C

steam to carbon ratio: 2; 3; 4

pressure: 2; 5; 9 bar

gas hourly space velocity: 2000 - 6500 sleducts/(lcat h)

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Operation load 38 115 [%]Porous burner temperature 910 1100 [°C]Temperature of the fixed catalyst bed 720 - 800 390 - 880 [°C]Pressure 7,3 7,3 [bar]S/C ratio 4 4 [moleH2O/atomC]Reformer ethanol inlet stream 3,45 10,36 [mole/h]Enthalpy stream of the ethanol 1,19 3,57 [kW]Product gas stream 42,89 128,9 [mole/h]Hydrogen stream of the product gas 14,90 44,63 [mole/h]Enthalpy stream hydrogen reformer 1,00 3,00 [kW]Burner hydrogen stream 7,5 22 [lN/min]Enthalpy stream hydrogen burner 1,35 3,96 [kW]Burner exhaust stream 23,7 64,3 [lN/min]

operation parameters of the Fraunhofer ISE-ReformerEuropean project:bioethanol reforming

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catalyst screening

T = 700 °CS/C = 4

⇒ selection of Ni-catalyst

0,5

0,6

0,7

0,8

0,9

1

2 3 4 5 6 7 8 9

pressure [bar]

H2-y

ield

[(m

ole/

h)H

2/(m

ole/

h)Et

h.]

Ni Pd Pt Ru Pe PtNi NiPd

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Ni catalyst

T = 700 °Cp = 2 bar

influence of S/C

H2CH4CO2CO

13,9

10,9

8,7

14,0

16,4

18,4

2,4

1,0

0,5

68,5

70,5

71,2

0,0 10,0 20,0 30,0 40,0 50,0 60,0 70,0 80,0

2

3

4

S/C-

ratio

molar fractionl [%,dry]

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10,3

8,8

7,7

17,4

18,5

19,3

10,3

7,3

4,3

61,5

65,1

67,7

0,0 10,0 20,0 30,0 40,0 50,0 60,0 70,0 80,0

2

3

4

S/C-

ratio

molar fraction [%,dry]

H2CH4CO2CO


Ni catalyst

T = 700 °Cp = 9 bar

influence of S/C

higher pressuredue to PSA

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HTS

Fe-oxide-catalystGHSV = 4000/hS/C = 4

377 374 372

422 424 425402 402 403

2,72

2,03

2,23

0

50

100

150

200

250

300

350

400

450

2 5 9pressure [bar]

tem

pera

ture

[°C

]

0

0,5

1

1,5

2

2,5

3

CO

con

tent

[mol

e %

]temperature top temperature middle temperature bottom CO content

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184173 175

193 195 196

177 177184

0,0860,087

0,135

0

50

100

150

200

2 5 9

pressure [bar]

tem

pera

ture

[°C

]

0,00

0,02

0,04

0,06

0,08

0,10

0,12

0,14

CO

con

tent

[mol

e%]

temperature top temperature middle temperature bottom CO content

LTS

Cu/Zn-catalystGHSV = 4000/hS/C = 4

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45,4 42,4 40,5

38,5 41,7 43,4

10,3 13,6 14,9

4,71,2 0,1

1,1 1,1 1,2

05

101520253035404550

gas

com

posi

tion

[mol

e%]

Reformer HT-shift LT-shift

CH4

CO

CO2

H2

H2O

CH4 CO CO2 H2 H2OEuropean project:bioethanol reforming

Results of reformer andCO-shift device

S/C = 4p = 9 bar

With CO fine purification:Reformate suitable for PEM- fuel cell

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Hydrogen generation from biogenic ethanol is attractive due to - good availability,- competitive costs,- „easy“ realisation of reforming process

Research of bioethanol reforming at Fraunhofer ISE:

- development of a compact steam reformer with preheatingof liquid reformer feedstream (with burner exhaust gas) andof the air for the burner (with the reformer product gas)

- development of a porous burner with stable combustion for offgas, methane, or ethanol

- optimisation of heat losses and performance

Outlook:

- reduction of volume and weight of the reforming unit- reduction of start-up time- further improvement of performance- cost reduction - longtime-operation to show catalyst stability

European project:bioethanol reformingSummary

Summary

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Outlook5 kW Fuel processor unitfor stationary electricitygeneration

Source: Nuvera Fuel Cells Europe, Milan, methanol reformer

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Thank you very much for your attention!

Documents

Research on the reforming of ethanol - Bioenergy LAMNET · Research on the reforming of ethanol Seite 2 Reforming of Ethanol, LAMNET-Workshop, Brasilia Introduction - regenerative