High Temperature Fuel Cell Tri-Generation of Power, Heat & H from ...

© National Fuel Cell Research Center, 2012 1/35

High Temperature Fuel Cell Tri-Generation

of Power, Heat & H2 from Waste

Jack Brouwer, Ph.D. December 6, 2012

AEE SoCal Chapter Monthly Luncheon


Outline

• Introduction and Background

• Tri-Generation/Poly-Generation Analyses

• OCSD Project Introduction

• OCSD Project Performance

• Summary


Introduction and Background

• Hydrogen fuel cell vehicle performance is outstanding

• Energy density of H2 is much greater than batteries

• Rapid fueling, long range ZEV

• H2 must be produced

• energy intensive, may have emissions, fossil fuels, economies of scale

• Low volumetric energy density of H2 compared to current

infrastructure fuels (@ STP)

• H2 handling (storage, transport and dispensing) can be energy and

emissions intensive

An emerging strategy is poly-generation

of hydrogen, heat and power from a

high-temperature fuel cell (HTFC)

There is a need for a distributed,

high-efficiency, low emissions hydrogen

production method able to use a

variety of feedstocks


Tri-Generation Energy Station Concept 1, 2, 3

Locally

available

feedstock:

Natural Gas,

ADG,

Landfill Gas, ….

Electricity

Heat

Hydrogen

Energy Station Concept Introduction and Background

1 Brouwer et al., 2001; 2 CHHN Blueprint Plan, 2005; 3 Leal and Brouwer, 2006



Poly-generation of Power, Heat and H2

• Advantages: 4, 5, 6

• H2 production is at the point of use averting emissions and energy

impacts of hydrogen and electricity transport

• Fuel cell produces sufficient heat and steam as the primary inputs

for the endothermic reforming process

• Synergistic impacts of lower fuel utilization increase overall

efficiency (i.e., higher Nernst Voltage, lower polarization losses,

lower cooling requirement and associated air blower parasitic load)

• Potential Disadvantage:

• Distributed production may not be compatible with carbon

sequestration

4 Leal and Brouwer, 2006; 5 O’Hayre, R., 2009; 6 Margalef et. al, 2008


High Temperature Fuel Cell (HTFC) Stack

• Solid Oxide Fuel Cell Example


CH4+H2O 3H2+CO

2H2+O2- 2H2O + 4e-

O2 + 4e- 2O2-

Electrolyte

Reformation rxn

Fuel cell rxn

AN

C

AT

H

load

Stack Operating Temperature Range = 650oC to 950oC

HE

AT

{CH4, H2O}

O2 Depleted

Air

O2(Air)

{H2, CO,

CO2}

{H2}

HE

AT

• Fuel Utilization Factor (Uf) = ~ 85%

• Air Utilization Factor = ~ 15 %

~ 60%

~ 30%

O2-


Outline





• Summary


~

C.C.

CH4 Air

Exhaust

gases

1

Water

S O F C

2

3

4

7 8

9

6

5

CH4

H2

H2O

Reformer

(1)

CH4

H2

H2O

Reformer

(2)

CH4

H2

H2O

Reformer

(3)

CH4

H2

H2O

Reformer

(4)

~

C.C.

Exhaust

gases

1

S O F C

2

3

4

7 8

9

6

5

CH4

H2

H2O

Reformer

(1)

CH4

H2

H2O

Reformer

(2)

CH4

H2

H2O

Reformer

(3)

CH4

H2

H2O

Reformer

(4)

Placement of a reformer in different locations:

Configuration 1 reformer after the air preheater,

Configuration 2 reformer after the water preheater,

Configuration 3 reformer after the natural gas preheater,

Configuration 4 reformer after the combustion chamber.

Cycle Configurations Air Water Natural Gas


Configuration 5: External reforming with

combustion chamber after the air preheater.

15

~

S O F C

H2

H2O

C.C.

Water Air

7

10

CH4

CH4

8

3

2

9

4 6

REF

11 12

Exhaust gases 13

14 16

5

1

Configuration 6: Internal reforming

1

C.C.

~

S O F C

H2

8 7

13

9

H2O CH4 Air

Exhaust gases

11

12

2 6 4

5 3

10

Cycle Configurations


0.00

0.50

1.00

1.50

2.00

2.50

3.00

3.50

1 (S

/C=2

)

1 (S

/C=3

)

2 (S

/C=2

)

2 (S

/C=3

)

3 (S

/C=2

)

3 (S

/C=3

)

4 (S

/C=2

)

4 (S

/C=3

)

5 (S

/C=2

)

5 (S

/C=3

)

6 (S

/C=2

)

6 (S

/C=3

)

Configurations

Hy

dro

ge

n p

rod

uc

tio

n [

g/s

]

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

Fir

st

La

w E

ffic

ien

cy

Hydrogen production Electrical efficiency Thermal efficiency Overall efficiency

Thermodynamic Analyses

• Energy performance analysis


0

1000

2000

3000

4000

5000

6000

7000

8000

0

0.1

0.2

0.3

0.4

0.5

0.6

0.7

0.8

0.9

1

1.1

1.2

1.3

0 1000 2000 3000 4000 5000 6000 7000 8000 9000 10000

Po

we

r D

en

sit

y [

W/m

2]

Cell

vo

ltag

e [

Vo

lts]

Current Density [A/m2]

Electrochemical heat at different utilization factors (P=5000 A/m2)

0.4 0.6 0.8 EMF 0.4 0.6 0.8

Poly-Generation Analyses

Electrochemical

Heat

]kW[hΔnV

)VV(Heat fH

max

cellmax

2

• Synergy #1: Electrochemical heat & voltage

Fuel Utilization Values


• Electrochemistry & Reformation Synergy #2 – Air Flow

30

40

50

60

70

80

90

100

0.4 0.5 0.6 0.7 0.8

Air

flo

w in

[km

ol/

hr]

Fuel Utilization Factor

Factor #1 electrochem.

heat


Factor#2 reformation

cooling


• EXAMPLE: Efficiency of a Poly-Generating Hydrogen

Energy Station (H2ES) without valuing heat


Electricity

production with

state-of-the-art

natural gas

combined cycle

Centralized SMR

Plant

(H2 production)

(Case: H2ES)

Poly-generating

HTFC

Fuel

Fuel

Fuel

Electricity

Hydrogen

η el,1 = 61.2%η el,2 = 51.7%η el,3 = 58.4%

η H2,1 = 80.9%η H2,2 = 54.9%η H2,3 = 83.5%

η el,pp = 60%

η H2,SMR = 79%

ηtot = 69.5%


Poly-Generation Dynamic Analyses

0 0.2 0.4 0.6 0.8 10

250

500

750

1000

Po

wer

[kW

]

0 0.2 0.4 0.6 0.8 10

20

40

H2 in

Tan

k [

kg

]

12:00 AM 6:00 AM 12:00 PM 6:00 PM 12:00 AM0.5

1

1.5

2

2.5

3

3.5

H2/C

O o

ut

of

co

llecto

r[g

/s]

H2

CO

• Diurnal dynamic operation of SOFC

• Hydrogen tank fills forcing end of tri-generation

• Control of system temperatures during transient is possible

12:00 AM 6:00 AM 12:00 PM 6:00 PM 12:00 AM950

1000

1050

1100

1150

1200

1250

1300

Tem

p [

K]

Tan,in

Tca,in

Tca,out

Tan,out


Outline





• Summary


STORAGE

TANK

ADG

HOT

WATER

HEAT

EXCHANGER ANAEROBIC

DIGESTION

GAS HOLDER

SLUDGE

DIGESTER

BOILER

HYDROGEN HYDROGEN

STORAGE

HYDROGEN

DISPENSER

FUEL

TREATMENT

AC

POWER

HIGH-T

FUEL CELL

World’s First Demonstration

• Orange County Sanitation District

• Euclid Exit, I405, Fountain Valley

• Support: DOE, ARB, AQMD

Renewable Tri-Generation of Power, Heat & H2

Sponsors/Participants:


OCSD Project – World’s First

• Installation complete, Operation on natural gas (6 months),

ADG operation underway for ~1 year

Renewable H2

Filling Station

ADG fueled

DFC-H2 ®

Production Unit


FCE

Equipment

Air Products

Equipment

Anode

Exhaust

Skid

DFC

(Direct

Fuel

Cell)

ADG Clean-

up Skid

Syngas

Compressor

Skid PSA Skid (pressure swing

absorption)

Compressor

Skid

Hydrogen

Storage

Tubes

Inverter

&

Electrical

BoP

Mechanical

BoP


Renewable Fuel Flexibility

Anaerobic Digester Gas (ADG) Clean-up

• Sulfur compounds: e.g., H2S, COS, ethers, thioketones,

mercaptans – all catalyst poisons

• Siloxanes – e.g., hexamethylcyclotrisiloxane (D3 =

((CH3)2SiO)3), octamethylcyclotertrasiloxane (D4),

decamethylcyclopentasiloxane (D5) – break down into

amorphous silica when heated, covering catalytic surfaces

• Halogens – catalyst poison, toxic

• Heavy metals – e.g., Cd, As, Hg, Pb – toxic, plate out to

cover surfaces

• High MW volatile organic compounds - coking


Need Robust ADG Clean-Up

• Gas composition variability data summarized

• FuelCell Energy developed rigorous design specifications

• Allow use of H2 in the clean-up system design for first time

• Quadrogen produced the winning bid

• Very robust & reliable system

• Siloxanes removed by -10°F temperature (Pioneer System),

water condensation and removal

• Sulfur compounds removed by HDS/zinc-oxide

• Polisher beds for both siloxanes and sulfur compounds

• Factory acceptance test passed in April, 2011

• Site installation and start-up successful in June 2011

• Only minor outages due to the clean-up skid


DFC® Fuel Cell

• CO2 Diluent in Biogas

inhibits FC Anode

Performance – all fuel

cells

• DFC® has improved

Cathode Performance

• CO2 neutral techology

High Temperature Internal Reforming

Direct FuelCell®

CH 4 + 2H 2 O 4H 2 + CO 2

Anode

Catalyst

CATALYST CATHODE

Electrolyte

Internal Reforming

H 2 + CO 3 H 2 O + CO 2 + 2e =

= 1/2O 2 + CO 2 + 2e CO 3

Steam

Hydrocarbon Fuel

e.g. Natural Gas / Coal Gas

Air

-


Increase robust operation and system availability

0

5

10

15

20

25

30

0 10 20 30 40 50

Dig

este

r P

ressure

0

50

100

150

200

250

300

0 10 20 30 40 50

Pow

er,

kW

0

50

100

150

200

250

300

0 10 20 30 40 50

Pow

er,

kW

P

ow

er,

kW

0

50

100

150

200

250

300

0 10 20 30 40 50

0

10

20

30

40

50

60

70

80

90

100

Power, kW

DG Flow, scfm

NG flow, scfm

Flo

w,

scfm

• Anaerobic Digester Gas (ADG)

Availability Naturally Fluctuates

• Initial plant response trip offline

• Automated fuel switching/blending

developed

• With fuel switching/blending, full load is

maintained and rapid recovery from

trips supported

Automated Fuel Switching/Blending


Hydrogen Co-Production

“Hydrogen Booster” Anode Off-Gas Shift Reactors, water

removal

• Use water-gas-shift (WGS) reaction (CO + H2O(g) → CO2 + H2)

• Also includes Regenerative Heat Removal (heat transfer)

• Overall impact is to increase hydrogen concentration to meet

the inlet requirements of the PSA and reduce the parasitic

separation load of the PSA

• Also includes water condensation and drop-out (removal)

• WATER INDEPENDENT


Hydrogen Purification

Hydrogen Purification from dilute low-pressure stream:

• Improvement in hydrogen purification cycle:

• Phase 1: 300 psig inlet, 75% H2 recovery

• Phase 3: 150 psig inlet, > 85% H2 recovery

• Patent issued to APCI (13 April 2010)

US Patent 7,695,545


Hydrogen Pipeline

• More than

1000 ft. long

• SS tubing

• Into utility

tunnel

• Underground

• Along Santa

Ana river fence

• To fueling

station


Hydrogen Fueling Station

• Dispenses at 35 and

70 MPa (5000 and

10,000 psi)

• Fully compliant with

SAE standards for

rapid fueling

• 3-minute 6kg fill

(empty -> full for

typical FCV)

• Pre-cooling down to

-40oC before

dispensing

• IR communications in nozzle

• High pressure compression and high pressure storage


Outline





• Summary


Steady State performance examples – Power & H2 only

• Overall efficiency 54.5% (Factory Test 8/28/09)

DFC @ 200 kW net AC

(without PSA)

Syngas 886 lb/hr

A/E

Skid PSA

225 kW

Gross AC + -

159 kW

Export to Grid

8.3 kW 39.4 kW Comp A Only

12.3 scfm

(3.9 lb/hr)

Hydrogen

Natural Gas 29.8 scfm, 491 kW eq.

Water 171 lb/hr, 60.2 scfm

19.8 scfm CO2

ADG Simulation

Syngas 407 lb/hr

Syngas 479 lb/hr

CO2 Return Gas

18.2 kW

Exceeds Efficiency Targets

Standard

Operation

NG or ADG

NG 10/27/10

268 kW

7.5 lb/hr H2

ADG 7/25/11

260 kW

7.6 lb/hr H2

ADG 7/28/11

260 kW

10.7 lb/hr H2

47% 54.3% 50.4% 53.2%

Site Tests


Additional Efficiency Improvements Possible

• CHHP Efficiency >70%

0%

10%

20%

30%

40%

50%

60%

70%

80%

90%

100%

NG 10/27/2010

268 kW Gross AC

7.5 lb/hr H2

NG 10/27/2010

260 kW Gross AC

7.7 lb/hr H2

NG 10/27/2010

260 kW Gross AC

10.7 lb/hr H2

Losses (Parasitic, Heat,Thermodynamic)

Exhaust Heat (to 120°F)

Hot Water (to 100°F)

Hydrogen

net AC


Grid Disturbance Issues

OCSD DFC-H2 Renewable H2 Production History

2-year Operating History at OCSD


OCSD Project – Quarterly Status Update

Last Quarter Performance:

MONTH OPERATING

HOURS GROSS AC GENERATED

kWh

NET AC GENERATED

kWh

July 665 146,528 96,061

August 595 121,520 69,468

September 720 153,099 91,286

Quarter Total

1,980 421,147 256,815


Outline





• Summary


Summary

• > 2M kWh electricity; > 25,000 lbs H2; > 9M scf ADG processed

• Demonstrated many features of tri-generation with DFC®

technology

• Water Independence

• Fuel Flexibility

• Ultra-low Emissions

• Met Efficiency Target

• Dispensing to vehicles (meeting FCV quality requirements)

• Demonstrated system robustness

• Number of trips (mostly due to inverter/power issues)

• Robust operation

• Remote operation (re-integration, de-integration)

• High level of safety

• Very popular site due to innovative technology and

application – large number of visitors

The UC Irvine Team

Credit: Steve Zylius/UC Irvine Communications


Recall: High Temperature Fuel Cell (HTFC) Stack

• Molten Carbonate Fuel Cell Example

Analyses of Synergies

CH4+H2O 3H2+CO

2H2+2CO32- 2H2O + 2CO2 + 4e-

O2 + 2CO2 + 4e- 2CO3

2-

Electrolyte

Reformation

Electrochemistry

AN

C

AT

H

load

Stack Operating Temperature Range = 550oC to 650oC

CH4, H2O

O2 Depleted

Air

O2, CO2

H2, CO,

CO2

HE

AT

2CO32-

Air Flow and parasitic blower power can be reduced

Endothermic

Exothermic


Energy System Dynamics & Control: Approach

First Principles Dynamic Models – Examples


Energy System Dynamics & Control: Approach

First Principles Dynamic Models – Examples

0 50000 100000 150000 2000000.6

0.61

0.62

0.63

0.64

0.65

FC

Voltage [

V]

Time [sec]

Experiment

Model

V

olt

age

[V]

Experiment

Simulation

0 50k 100k 150k 200k0.6

0.61

0.62

0.63

0.64

0.65

Time [s]

0 50000 100000 150000 2000000.6

0.61

0.62

0.63

0.64

0.65

FC

Voltage [

V]

Time [sec]

Experiment

Model

V

olt

age

[V]

Experiment

Simulation

0 50k 100k 150k 200k0.6

0.61

0.62

0.63

0.64

0.65

Time [s]

1000 2000 3000 4000 5000

Time [s]

56

58

60

62

64

66

Vo

ltag

e [V

]

Simulation

Experiment

1000 2000 3000 4000 5000

Time [s]

56

58

60

62

64

66

Vo

ltag

e [V

]

Simulation

Experiment

650oC, 1 atm.

ExperimentalSimplified ModelAgglomerate Model

0 5 10 15 20 25 30Time [s]

0.86

0.84

0.82

0.80

0.78

0.76

0.74

0.72

0.70

Vo

ltag

e [V

] 650oC, 1 atm.



0 5 10 15 20 25 30Time [s]

0.86

0.84

0.82

0.80

0.78

0.76

0.74

0.72

0.70

Vo

ltag

e [V

]

Siemens Westinghouse 220 kW

SOFC-GT Hybrid SystemPlug Power 5 kW PEM GenSysSingle Cell MCFC Test Stand


Poly-Generation Renewable Energy System

Orange County Sanitation District (OCSD) Project

Sponsors & Participants


• Steady-State AspenPlus® Modeling


HTFC Anode exhaust preparation PSA

550

1

561

42

1.0

REFRMATE

467

1

1603

52

1.0

13

700

1

919

46

1.0

ANEX

617

1

1244

41

1.0CAEX

0

HEATLOS

-901

FCWORKW

800

0

919

48

1.0

ANEX2-0

QEQUI

0

QFCNETQ

15

2

450

25

0.0

21

15

2

450

25

0.0

31

265

20

393

19

1.0

5

47

20

373

18

1.0

12

110

2

450

25

0.0

33

47

20

20

1

0.0

14

77

5

393

19

1.02

101

1

526

29

0.4

17

117

2

2702

150

0.01

22

15

2

450

25

0.06

277

5

393

19

1.03

62

2

450

25

0.0

24

77

1

526

29

0.025

235

1

919

48

1.07

77

1

393

19

1.0

18

25

1

1246

43

1.015

323

7

1246

43

1.016

106

30W

57

1

357

10

1.011

57

20

16

8

1.0

10500

2

919

48

1.0HSUIN2

200

2

919

48

1.0

8

0

0

9

32

500

2

128

8

1.0

FUELIN

FC

ANEQ

Q=0

Q

MIXER

QMIX

B13

Q=0

B4

W=35

B10

W=0

B9

Q=0

B3

Q=0

B2

W=106

B7

Q=0

B1

Q=0

B12Q=0

B5

W=37

B17

Q=0

REFORM

Q=0

Heat and Material Balance Table

Stream ID 8 32 7

Temperature C 200.0 234.7

Pressure bar 1 .793 1 .448 1 .448

Vapor Frac 1 .000 1 .000

Mole Flow kmol/hr 48.000 0 .000 48.000

Mass Flow kg/hr 919.095 0 .000 919.095

Volume Flow cum/hr 1048.382 0 .000 1395.517

Enthalpy MMkcal/hr -2 .425 -2 .425

Mole Flow kmol/hr

O2 trace

N2

AR

H2 8 .087 9 .573

CO 1 .513 0 .027

CO2 6 .487 7 .973

H2O 31.913 30.427

CH4 trace trace

HX1

Q=-0

PUMP2

W=0

15

1

450

25

0.0

H20IN

SEP1

102

1

94

5

0.42

WASTEW

102

1

432

24

0.42RECVDWAT

HX2

Q=0

96

1

432

24

0.99RCVDSTM

0

HEAT1

PUMP1

W=0

15

1

2702

150

0.0

WTRIN1

15

2

2702

150

0.0

WATER2

Hydrogen Separation Unit (HSU)

Water-Gas Shift

Reactor (WGSR)


Poly-Generating Efficiencies for HTFC

• Some have recently reported poly-generation efficiencies

that are misleading and unattractive

• Recent NFCRC paper published to address this issue


Etot Poly-generating

HTFC

Ee-

Electricity

(Pnet)

Heat (Qnet)

Chemicals

(C)

EC

EQ

Efficiency of poly-generating high temperature fuel cells, J. Power Sources,

Volume 196, Issue 4, 15 February 2011, Pages 2055-2060

Pere Margalef, Tim Brown, Jacob Brouwer, Scott Samuelsen


• Poly-Generating Efficiencies for HTFC

• State-of-the-Art plant efficiencies


Electrical Efficiency

(LHV) Thermal Efficiency (LHV)

Chemical Product

Efficiency (LHV)

Total Mixed Efficiency

(LHV)

ηe− ηQ ηC ηtot

Pnet Ee− Qnet EQ C EC (Pnet + Qnet + C) Etot

Comparable

Efficiency Considered

Value (based

upon LHV) Comments

Power plant Efficiency

ηPP

0.47 Distributed electricity generation using a stand-alone HTFC

without poly-generation or co-generation [6]

0.92 Average U.S. T&D system efficiency [7]

0.60 Typical modern natural gas combined cycle plant [7]

Boiler Efficiency

ηboiler

0.60 Fueled boiler at less than full load [5]

0.85 Natural gas boiler at full load [5]

Chemical Plant

Efficiency ηCP

0.79 Centralized steam methane reformation (SMR) to produce pure

hydrogen from natural gas [8]

0.65 Centralized methanol production from natural gas [9]

0.65 Distributed SMR to produce pure hydrogen [10]


• Efficiency of Poly-Generating Systems


Methodology Electrical Efficiency

ηel = Pnet /Ee−

Thermal Efficiency

ηth = Qnet /EQ

Chemical Product

Efficiency

ηC = C/EC

(1) State-of-the-art

method

Pnet

Etot − Qnetηboiler

− CηCP

Qnet

Etot − Pnet

ηPP−

CηCP

C

Etot − Pnet

ηPP−

Qnet

ηboiler

(2) Ideal

method

Pnet

Etot − Qnet − C

Qnet

Etot − Pnet − C

C

Etot − Pnet − Qnet

(3) Supplemental

input method

Pnet

Etot − EQ − ECP

Qnet

Qnet − Eburner ηburner ηboiler

+ EQ

C

ECP


Hydrogen Compression and Storage

Production Site:

Hydrogen compression:

• PDC Piston-metal diaphragm compressor

• Stationary high-pressure compressor, four-staged water-

cooled, 11–15 kW, 30–50 Nm3/h, 45 MPa (~6500psi) for

storage at site and in pipeline

Hydrogen storage:

• Six (6) metal tubes

• Storage at ~6500psi

• Total storage capacity of ~120 kg


Hydrogen Compression and Storage

Fueling Station:

Hydrogen compression:

• Hydro-Pac, single stage, piston intensifier

• 6,000 – 12,000 psi compressor, 40 hp motor

Hydrogen storage:

• Three (3) carbon fiber tanks

• Storage at ~10,000 psi

• Total storage capacity of ~36 kg

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