Project Title: Advanced Thermal Hydrogen CompressionContractor: Ergenics, Inc.

Advanced Thermal Hydrogen Compressionpresented to the

US DOE Hydrogen and Fuel Cells Program

2003 Annual Merit ReviewMay 20, 2003

by

David H. DaCosta (presenter) and Mark Golben

Ergenics, Inc.373 Margaret King Ave.

Ringwood, NJ 07456(973) 728-8815

dacosta@ergenics.com

Project Title: Advanced Thermal Hydrogen Compression Contractor: Ergenics, Inc.Relevance / Objective

Project Objective: Develop an advanced thermal hydrogen compressor that operates in conjunction with advanced hydrogen production technologies and improves the efficiency and economics of the compression process. Thermal hydrogen compression must offer a sustainable competitive advantage over mechanical compression for market penetration.

Relevance to National Technical Targets:H2 Cost: Reduce compression energy costs by an order of magnitude to

meet the H2 cost goals of:Long Term: $1.50/gallon of gasoline equivalent (2010)Near Term: $3.00/gallon of gasoline equivalent (2004)

Energy Density: Demonstrate pressures of 5,000 and 10,000 psi to support high pressure tank development.

H2 Purity: Increase H2 quality to protect both fuel cell catalyst and advanced hydrogen storage materials. (≤10 ppm CO)

Complex/Carbon: Knowledge of impurity-effects on compressor hydrides will establish a baseline for understanding impurity impact on advanced storagematerials (alanates & carbon nanomaterials).

Slide 2 of 16

Project Title: Advanced Thermal Hydrogen Compression Contractor: Ergenics, Inc.Approach

0.0 0.2 0.4 0.6 0.8 1.0 1.20.1

1

10

100

50

5

0.5

25oC

175oC

100oC

40oC

70oCPr

essu

re, A

tm H

2

Hydrogen:Metal Atomic Ratio

Thermal Compression withMetal Hydride Alloys

A modest increase in temperature results in a large increase in pressure.

Compression energy can be provided by hot water, rather than electrical power.

High compression ratios are achieved by staging alloys with increasing plateau pressures.

Hydride alloys and systems must tolerate impurities and elevated temperatures.

Slide 3 of 16

Project Title: Advanced Thermal Hydrogen Compression Contractor: Ergenics, Inc.Approach

Long LifeTolerate ImpuritiesHigh T alloydevelopment

Materials

Long LifeTolerate ImpuritiesHigh Pressures

Materials

Preliminary DesignTotal Eval. Cost Est.Safety Analysis

System

Classify H2 qualityDevelop approaches tomitigate impuritiesDefine product (~60%)Fe

asib

ility

Fab. pilot comp. & teststand

Determine impuritythresholdsInvestigate compressionwith purificationTest multi-stage systemHigh P alloy development

Valid

ate

& Te

st

Needs: (Market & Reviewer Feedback)Waste heat sources are unique and arehard to integrate.Better purification technique for CO &CO2

Look at closed loop heater/coolerReduce energy costIncrease efficiency with higher temp.Reuse vented H2

Include heater/coolerMeasure EfficiencyNew Purification MethodSafety Analysis

System

Customer NeedsDesign StandardsSafety AnalysisMiniature Hydride HX:

ManufacturabilityCost Improvement

Phase 1 FY00

Phase 2 FY02Full Scale Demonstration

FY04

Phase 3 FY03

Ref

ine

into

Pro

duct

Slide 4 of 16

Approach

M

MH20H2Mix

COH2Mix

CO2H2Mix

CH4H2Mix

CO

CO2

CH4

CHECK VALVES: VENT TO ATM

H20Analyzer

CO/CO2/CH4Analyzer

"T" Tank Gas Cylinders

Vent to ATM

HydrideHeat Exchanger /

PropaneHeater

Liquid to AirHeat Exchangerwith Fan

LiquidMake-upReservoir

M

Drain

HEATINGSYSTEMLOOP

SYSTEMCOOLING

LOOP

Compressor

Vacuum

SurgeAccumulator

AirEliminator

Vent

Desorption

AbsorptionThermocouple

Over TempSafety Switch

BurnerShut OffFlowSwitch

PUREH2

T1 T2 T3 T4 T5

VI V2 V3 V4 V5

V10V9V8V7V6

CV5CV4CV3CV2CV1

PR1 PR2 PR3 PR4 PR5

PRV1

GAS SUPPLY SECTION

SV1

BPR2

PT1

V11

SV2

T6

AUTOMATICVENTING SECTION

PR6

V13 V14

FM4

FM3

CV9 CV10

GAS ANALYZER SECTION

HYDRIDE COMPRESSOR SECTION

BPR1PT2

PG1

PG2

PRV2

V15 F1

V12 FM1

FM2

PRV3(100 psi)V17FM5CV12SV3V16CV11PG3

T7

PRV4(100 psi)Vent

EliminatorAir

AccumulatorSurge

PG4

V18FM6CV13SV4PG5

CV14SV5 F4

F3CV15SV6

V20PRV6

V19PRV5Drain

Propane

(1000 psi)

Vacuum

THIS DOCUMENT AND ITS CONTENTS:

Piping & Instrumentation Diagram

Thermal Hydride Compressorand Test Station P&ID, showing the closed loop heating and cooling system

Project Title: Advanced Thermal Hydrogen Compression Contractor: Ergenics, Inc.

Slide 5 of 16

Project Title: Advanced Thermal Hydrogen Compression Contractor: Ergenics, Inc.Approach

The compressor bed is a miniature hydride shell and tube heat exchanger measuring 0.75 inches in diameter by 60 inches long (19 mm D x 1524 mm L).

Hydride alloy is contained within four 0.125 inch diameter (3.2 mm) Inconnel tubes that are welded to a stainless steel tube sheet on one end and closed on the other end.

The tube “bundle” slides into the stainless steel shell, which is welded to the back side of the tube sheet. Heating/cooling fluid enters the shell via the perpendicular nozzle. The hydrogen manifold contains a filter disc to prevent alloy migration.

Slide 6 of 16

Project Title: Advanced Thermal Hydrogen Compression Contractor: Ergenics, Inc.Approach

Hydride Compressor Test Stand

Compressor

Inert GasVent Valve

GasAnalyzers

VentCollection

Tank

H2 Inlet

CheckValve

H2 Outlet

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Project Title: Advanced Thermal Hydrogen Compression Contractor: Ergenics, Inc.Project Timeline

FY2000

FY2001

FY2002

FY2003

FY2004

Determine hydride alloys’ resistance to disproportionation.Validate compressor operation at >5,000 psi.Determine hydride alloys’ tolerance to impurities while cycling.Test effectiveness of three purification techniques (passive purification for H2O & O2, elevated temperature desorption for CO & CO2, inert gas venting for N2 & CH4 ).Determine if compression with purification is a viable alternative for improving fuel cell performance.Reduce capital cost via miniature hydride heat exchangers and rapid cycling.

Feasibility

Full ScaleDemonstration

Validateand Test

Refine ProductDesign

To be proposed

Quantified H2 quality anticipated from advanced and renewable production techniques.Preliminary design and Safety Analysis

Status: Completed In Progress FutureSlide 8 of 16

Project Title: Advanced Thermal Hydrogen Compression Contractor: Ergenics, Inc.Accomplishments / Progress - H2 Cost

Hydride Compression’s Low Energy Cost WillSubstantially Reduce the Cost of Hydrogen

H2 Quantity 1 kg 1 kg

Inlet Pressure 15 psia 15 psia

Outlet Pressure 5,000 psia 10,000 psia

Adiabatic Work 1,960 watt hours = 6,690 BTU 2,194 watt hours = 7,485 BTU

Compressor Type Mechanical Hydride Mechanical Hydride

Efficiency 12% 15% 6% 10%

Fuel Electricity at $0.05 / kWh

Natural Gas at $3 / MM BTU

Electricity at $0.05 / kWh

Natural Gas at $3 / MM BTU

Comp. Energy Cost / kg H2 $0.82 $0.14 $1.83 $0.23

Energy Cost / H2 Cost at $3.00/gge (2004)* 27% 5% NA NA

Energy Cost / H2 Cost at $1.50/gge (2010)* 55% 9% 122% 15%

* FY 2004 Congressional Budget Request

gge = gallon of gasoline equivalent, which is ~ 1 kg H2

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Project Title: Advanced Thermal Hydrogen Compression Contractor: Ergenics, Inc.Accomplishments / Progress - Energy Density

0

1000

2000

3000

4000

5000

6000

7000

P In P Out Temp In Temp Out

Pres

sure

(psi

a)

0 1000 2000 30000

20406080

100120140160180

Time (seconds)

Tem

p (C

)

Compressed hydrogen is vented via a back-pressure regulator. The regulator was set at 5,000 psi (34 MPa) for most cycles, but was briefly increased to 6,000 psi (41 MPa) for the cycle that starts at Time = 2,000 seconds. The compressor is capable of operation to 10,000 psi (69 MPa).

1800 2000 2200 2400 26000

2000

4000

6000

P (P

SIA

)

1800 2000 2200 2400 26000

50

100

150

200

T (C

)

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Project Title: Advanced Thermal Hydrogen Compression Contractor: Ergenics, Inc.Accomplishments / Progress - Energy Density

High Outlet Pressure

• Single Stage• Inlet P = 1,200 psia• Outlet P = >8,000 psia• 10,000 psia will be

achieved with elevated temperature

Pressure responds tofluctuation in water temperature as the heatercycles on and off

0

2,000

4,000

6,000

8,000

10,000

Pres

sure

(psi

a)

0

50

100

150

200

9,000 9,500 10,000Time (seconds)

Tem

pera

ture

(C)

Outlet Pressure

Inlet Pressure

165

170

175

180

9250 9500 9750

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Project Title: Advanced Thermal Hydrogen Compression Contractor: Ergenics, Inc.Accomplishments / Progress - H2 Purity - Tolerating Impurities (1 of 2)

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21

Cycle No.

5

6

7

8

9

10

Lite

rs H

2 pe

r Cyc

le

Pure H2300 PPM CO

5

6

7

8

9

10

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25

Cycle No.

Lite

rs H

2 pe

r Cyc

leWhen CO is added to feed H2, alloy capacity-per-cycle gradually declines.

A recently developed, proprietary CO conversion feature maintains alloy capacity.

Operation w/o COConversion Feature

Operation with COConversion Feature

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Project Title: Advanced Thermal Hydrogen Compression Contractor: Ergenics, Inc.Accomplishments / Progress - H2 Purity - Tolerating Impurities (2 of 2)

Compressor Alloy PCT Isotherms

0.0 0.5 1.0 1.5100

200

300

400

500600700800900

5th Abs 25 C(After 26 cycleson 300 ppm CO)

2nd Abs 21 CAfter 10 cycleson 300 ppm CO)

1st Abs 20 C(virgin alloy)

(Mass Percent H2 in Hydride, %)

(Pre

ssur

e in

psi

a)PCT Isotherms* indicate the alloy was not damaged by CO. The differences in plateau pressures are a function of ambient temperature.

* PCT = pressure, composition, temperature

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Project Title: Advanced Thermal Hydrogen Compression Contractor: Ergenics, Inc.Accomplishments / Progress - H2 Purity - Removing CO (1 of 2)

10,000 15,000 20,000 25,000 30,000Time (seconds)

0

50

100

150

200

250

300

PPM

CO

CO2

CH4

Pure H2 Inlet H2 with 300 PPM CO Pure H2

Outlet Hydrogen Composition w/o CO Conversion FeatureWith 300 ppm inlet CO, CO outlet concentrations approach 250 ppm

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Project Title: Advanced Thermal Hydrogen Compression Contractor: Ergenics, Inc.Accomplishments / Progress H2 Purity - Removing CO (2 of 2)

Outlet Hydrogen Composition with CO Conversion Feature

300 ppm Inlet CO is reduced to 10 ppm to protect fuel cell electrode catalyst.CH4 will be removed via inert gas venting, made possible by the >1,000 ppmspike that is released at the very beginning of each desorption cycle.

0

200

400

600

800

1,000

1,200

0 5,000 10,000 15,000 20,000 25,000Time (seconds

Out

let C

H4

& H

2O P

PM

0

24

68

10

1214

1618

20

Out

let C

O &

CO

2 PP

M

CO CH4

H2O

CO2

StartupAdjustments

Inlet H2 with 300 PPM CO

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Project Title: Advanced Thermal Hydrogen Compression Contractor: Ergenics, Inc.Collaboration and Future Plans

Ergenics is contributing to the International Energy Agency Hydrogen Implementing Agreement for Solid and Liquid State Hydrogen Storage Materials.

Submitting patent application for CO conversion feature.

Seeking a H2 refueling site and partners for a full scale thermal hydrogen compressor demonstration for FY2004. Are in discussions with three site operators, two hydrogen producers and a major oil company.

Slide 16 of 16