Development of a kW Prototype Coal-based Fuel Cell

DE-FG36-06GO86055

Steven S. C. ChuangDepartment of Chemical and Biomolecular Engineering

The University of AkronAkron, OH 44325-3906 USA

Acknowledgement: US Department of Energy, Ohio Coal Development Office, Ohio Board of Regents; Univ. of Akron Students: J. Fisher, D. Miller, F. Guzman, R. Singh, and Z. Yu,

FCP 41

This presentation does not contain any proprietary or confidential information

Relationship between fuel processing and fuel cells

Rita Bajura, CCPI-Round 2, Planning Workshop, Aug. 23, 2003_

Coal is Important

1. Prices current as of Jan-March 2005 (www.eia.doe.gov)2. Natural Gas prices DOE (Average Commercial

Prices)3. Gasoline & Diesel Fuel Prices (tonto.eia.doe.gov)

Coal Fuel Cell

Source: The University of Akron

Disposal

Coal-based Fuel Cell

Coal Gasification + Cleaning + Syngas Fuel Cell and Turbine/ Generator

J. Johnson, Volume 82, Number 08, Chemical & Engineering News, February 23, 2004

Pt Ink

Fuel/CH4

Effluent

CH4 + CO2 2CO + 2H2CH4 + H2O CO2 + 3H2CO + H2O CO2 + H2CH4 + 0.5 O2 CO + 2H2

O2-

CH4 + 3O2- CO2 + H2O + 2e-

Electrolyte Disc

Cathode catalyst layer

Anode catalyst layer

Pt Wire

Yttrium-stablized Zirconia (>950 °C)Galladium-doped Ceria (>600°C)

O2 + 4e- 2O2-

A Oad Products T (°C)

CH4 Oad CO, H2, CO2, H2O 600-1200

CnH2n Oad CnH2nO, CO2, H2O

C Oad CO2 550-950

vA

RL

SOFC Materials and Reactions

Ni/YSZ-Anode-supported fuel cell with H2 feed

0 100 200 300 400 500 600

0.4

0.5

0.6

0.7

0.8

0.9

1.0

1.1

800 degreeVol

tage

(Vol

ts)

current density (mA/cm2)

H2=20cc/minVopen=1.010 VIclose=940 mA/cm2

850 degree

area=0.5 cm2

0 100 200 300 400 500 6000.0

0.2

0.4

0.6

0.8

1.0

1.2

0

50

100

150

200

250

Current Density (mA/cm2)

volta

ge (V

)

Pow

er (m

W/c

m2 )

H2 after coking

CH4

H2

20 μm Ni-based anode/600 μm YSZ disk/50 μm LSM/YSZ cathode

Cathode area=0.5 cm2

Temperature=850 oC

PROXIMATE ANALYSIS ULTIMATE ANALYSIS

% Moisture as received 4.15 % Carbon 83.99

Dry % ash 4.80 % Hydrogen 5.50

Dry % volatile matter 37.98 % Nitrogen 1.88

Dry % fixed carbon 57.22 % Oxygen 8.63

SULFUR FORMS

% Pyritic 0.70 % Organic 1.21

% Sulfate 0.01 % Total 1.92

CALORIC VALUE (BTU/lb) 14258

EQULIBIRUM MOISTURE (%) 7.98

Ohio Coal no. 5

LCathode

Anode

O2 + 4e- 2 O2-

C + 2O2- CO2-

Electrolyte

Pfeiffer QMS200Mass Spectrometer

Picture of the fuel cell assembly

Anode

Cathode

Electrolyte

Ceramic seal (Aremco)

Ar/Hesaturator

Mass flow controller

NI-DAQ/Labview

V, I

SRI 8610 CGC

FuelL

(2-a)

(2-b)

0

0.2

0.4

0.6

0.8

1

1.2

0 50 100 150

Volta

ge (V

)

Coal Fuel Cell

Methane Fuel Cell

Current density (mA/cm2)

Comparison of IV curves for Promoted-Metal Anode SOFC at 900 oC

200 μm

400 μm

200 μm

Coke before reaction

Coke after reaction

Fly ash after reaction

Coke and fly ash after the SOFC reaction in the reactor

Coal Gas Fuel Cell

Temperature(degC)

H2 (m/e = 2)

HD (m/e = 3)

C (m/e = 12)

CH4 (m/e = 16)

CO ( m/e = 28)

CO2 (m/e = 44)700

(60 min)27 800

(60 min)900

(60 min)950

(60 min)

AB C D E F G H I

MS

Inte

nsity

(a.u

.)

2e-10

SO2 ( m/e = 64)

MS Profiles during Gasification of Ohio Coal # 5

0

0.2

0.4

0.6

0.8

1

0 10 20 30 40 50 60

Vol

tage

(V)

Current Density(mA/cm2)

AB

C

DE

FGH

I

V-I Curves of Coal Gas Fuel Cell

Efficiency of Fuel Cells

John F. Cooper, Direct Caron Fuel Cell Workshop, NETL, July 30, 2003

Research in Coal-based Fuel Cells

• The performance of all the fuel cells is limited by the rate of ion diffusion across the membrane.

• Solid Oxide Fuel Cell– Long Term Catalyst Activity (poisoning of anode

catalyst)– Material compatibility – Robustness (Strength of the fuel cell assembly)

Ar/HeFTIR Bench

Detector

Computer Controlled Switching valve

64 ChannelsNI-DAQ card Labview

Quadrupole Mass Spectrometer

SRI 8610GC

Fuel Cells

Fuel Cell Testing System

Summary • Power density: Petcoke> Coal > Coal gas > CH4

• Fly ash produced from coal at 950 0C did not foul the anode catalyst surface.

• Future Tasks:– Task 1: Improvement of the anode catalyst structure and

the interface between electrode and membrane. – Task 2: Refinement of the techniques for fabrication of the

fuel cell assembly – Task 3: Selection and testing of interconnect materials for

the coal-based fuel cell. – Task 4: Investigation of the design factors for the coal

injection and flyash removal systems. – Task 5: Design and fabrication of a 5 kW prototype coal

fuel cell.