INL RESEARCH & DEVELOPMENT

Science

Arizona Public Service

Alternative Fuel Pilot Plant & Hydrogen

Internal Combustion Engine Vehicle

Testing

Alternative Fuel Pilot

Plant

The Arizona Public Service

Alternative Fuel Pilot Plant is

a model alternative fuel

refueling system, dispensing

hydrogen, compressed natural

gas (CNG), and hydrogen/

CNG blends (HCNG). The

plant is used daily to fuel

vehicles operated in Arizona

Public Service’s fleet.

Hydrogen Subsystem

The plant’s hydrogen system

consists of production,

compression, storage, and

dispensing. The hydrogen

produced is suitable for use in

fuel cell-powered vehicles, for

which the minimum hydrogen

purity goal is 99.999%.

Hydrogen is produced using

an electrolysis process that

separates water into hydrogen

and oxygen.

At present, the hydrogen is

compressed and stored at a

maximum operating working

pressure of 6,100 psi. The

facility has over 17,000 scf of

high-pressure hydrogen

storage capacity and 9,000 scf

of low-pressure hydrogen

storage capacity. The dispenser can fuel vehicles at

pressures up to 5,000 psi.

Compressed Natural

Gas Subsystem

In addition to producing

hydrogen, the plant also

compresses natural gas for

use as a motor fuel. CNG

vehicles typically have 3,600-

psi storage tanks. However, to

fill a vehicle’s onboard tanks,

storage pressures must be

higher. The APS system

compresses natural gas to

The INL manages the light-duty vehicle testing activities of the U.S. Department of

Energy’s Advanced Vehicle Testing Activity (AVTA). As part of this activity, INL and

AVTA teamed with Electric Transportation Applications and Arizona Public

Service (APS) to develop the Alternative Fuel Pilot Plant that produces and dispenses hydrogen on site. The hydrogen is produced through electrolysis by operating a PEM fuel cell in

reverse. The Pilot Plant also compresses natural gas on site and fuels internal combustion

engine test vehicles that operate on 100% hydrogen, and blends of 15 to 50% hydrogen and

compressed natural gas.

pressures up to 5,000 psi

using a three-stage cascade

pressure arrangement.

Hydrogen and Hydrogen/CNG (HCNG)

Internal Combustion

Engine Vehicle Testing

The U.S. Department of

Energy’s Advanced Vehicle

Testing Activity (AVTA) is

evaluating hydrogen and

Alternative Fuel Pilot Plant and fueling

island (above) and hydrogen lowpressure and two high-pressure

storage tanks with PEM electrolyzer

(inset at left).

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INL RESEARCH & DEVELOPMENT

Continued from front

05-GA50193-03

HCNG internal combustion

engine vehicles in closedtrack and laboratory environments (baseline performance testing), as well as in

real-world applications –

including fleet testing and

accelerated reliability testing

(accumulating life-cycle

vehicle mileage and operational knowledge within 1 to

1.5 years). Emissions testing

has also been conducted on

several vehicles.

In addition to reducing the

use of petroleum, using

hydrogen and HCNG as a

fuel in internal combustion

engine vehicles provides air

emissions benefits. Testing

hydrogen internal combustion engine vehicles also

supports development of the

hydrogen infrastructure

needed for fuel cell vehicles.

Management Contact

Tim Murphy

208-526-0480

Timothy.Murphy@inl.gov

Technical Contact

Jim Francfort

208-526-6787

James.Francfort@inl.gov

For more information

The AVTA, along with its

testing partners APS and

Electric Transportation

Applications, is operating

several 100% hydrogen

internal combustion engine

vehicles – with Ford and

Mercedes Benz engines –

as well as a dozen internal

combustion engine vehicles

Additional information about Arizona Public

Service’s Alternative Fuel Pilot Plant and

these advanced alternate-fueled internal

combustion engine test vehicles can be found

at: http://avt.inel.gov/hydrogen.html

Facts about Arizona Public Service’s Alternative Fuel Pilot Plant

• Location – Downtown Phoenix, Arizona

• Objectives:

– Evaluate the safety and reliability of operating internal combustion engine (ICE)

vehicles on hydrogen and blended HCNG fuels

– Quantify ICE hydrogen and HCNG vehicle costs, performance and emissions

– Ascertain the safety issues for a hydrogen production operation in a commercial

setting

– Develop a working model of a refueling system for ICE and fuel cell vehicles, and

evaluate the vehicle fueling infrastructure and vehicle-to-infrastructure interface

• Hydrogen Generator – PEM fuel cell, 57 kW, 300 scfh hydrogen output

• Hydrogen Compressor – Oil free, three stage, diaphragm compressor, 99.9997% purity

• Hydrogen Dispenser – Dispenses hydrogen up to 5,000 psi

• HCNG and CNG Dispenser – Dispenses HCNG and CNG up to 3,600 psi

• CNG Boot Compressor – 300 scfm @ 60 psi

• CNG Main Compressor – 350 scfm @ 4500 psi

• High Pressure CNG Storage – 50,000 scf @ 4,000 psi

• Fuel Dispenser – Pure hydrogen or CNG and HCNG blended fuels, with metering and

electronic billing interface

(including Daimler Chrysler,

Ford and General Motors

vehicles) that operate on 15

to 50% HCNG blends.

Various fuel blends have

also been tested in a Ford F150 to allow the comparison

of performance and emissions impacts.

INL is a U.S. Department of

Energy national laboratory

operated by Battelle Energy

Alliance