TOPIC:

PROTON EXCHANGEMEMBRANE FUEL CELL

By-

ABU DARDA ZILLI

PEM Fuel Cell

REPORTERS

Aliñabon, Louella Ann

Delima, Venus

Dizon, Clark

Inot, Lysa

Lamanilao, Juphil

Tuquib, Percy

What is PEMFC?

Contents

OVERVIEW of FUEL CELL

HISTORY of PEMFC

Contents

Basic Elements in a PEMFC

How PEM Fuel Cell Works

How PEM FC SYSTEM works

PEM FUEL CELL Applications

The Current PEM Market

Part II

Overview of a Fuel CellA fuel cell consists of two electrodes sandwiched around an electrolyte. Oxygen passes over one electrode and hydrogen

over the other, generating electricity, water and heat.

A fuel cell system which includes a "fuel reformer" can utilize the hydrogen from any hydrocarbon fuel -

from natural gas to methanol, and even gasoline.

Different Types of Fuel Cell

Description:PAFC - uses phosphoric acid as the electrolyte.

(MCFC) uses high-temperature compounds of salt (like sodium or magnesium) carbonates (chemically, CO3) as the electrolyte.

(AFC) operates on compressed hydrogen and oxygen. They generally use a solution of potassium hydroxide (chemically, KOH) in water as their electrolyte.

(SOFC) uses a hard, ceramic compound of metal (like calcium or zirconium) oxides (chemically, O2) as electrolyte.

PROTONEXCHANGEMEMBRANE

(PEM) works with a polymer electrolyte in the form of a thin, permeable sheet.

History of PEM Fuel Cell

PEM technology was invented at General Electric through the work of Thomas Grubb and Leonard Niedrach.

GE developed a small fuel cell for a program with the U.S. Navy's Bureau of Ships (Electronics Division) and the U.S. Army Signal Corps. The unit was fueled by hydrogen generated by mixing water and lithium hydride.

GE developed PEM water electrolysis technology for undersea life support, leading to the US Navy Oxygen Generating Plant.

Los Alamos National Lab and Texas A&M University experimented with ways to reduce the amount of platinum required for PEM cells.

19601960

mid-1960smid-1960s

mid-1970smid-1970s

1990s1990s

1980s1980s The British Royal Navy adopted this technology in early 1980s for their submarine fleet.

What is PEM Fuel Cell?

Polymer Electrolyte Membrane FC

Description

Concept

- consists of an electrolyte membrane sandwiched between an anode (negative electrode) and a cathode (positive electrode).

PEM fuel cells work with a polymer electrolyte in the form of a thin, permeable sheet and allow hydrogen protons to pass through but prohibit the passage of electrons and heavier gases.

- a thin, solid, organic compound, typically the consistency of plastic wrap and about as thick as 2 to 7 sheets of paper. This membrane functions as an electrolyte: allows the solution to conduct electricity

PEM Fuel Cell Basics

Fuel cells are operationally equivalent to a battery.

For automotive applications hydrogen is the fuel choice.

Low temperature; Polymer Electrolyte Membrane (PEM) type cells are the standard devices.

The reactants or fuel in a fuel cell can be replaced unlike a standard disposable or rechargeable battery.

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42

5

3

Electrochemical energy comes from the reaction: ½ H2 + ½ O2 → H2O.

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Theoretically the maximum voltage that this reaction can generate is 1.2 V. However, in practice the cell usually generates about 0.7 V to 0.9 V and about 1 W cm-2 of power.

What is PEM Fuel Cell?

Electrolyte

SystemOutput

CHPEff.

ElectricalEff.

OperatingTemp.

50 - 100°C122 – 212°F

53 – 58% (transportation)25 – 35% (stationary)

Solid organic polymer poly(perfluorosulfunic acid)

1KW – 250 KW

70 – 90%(low grade waste heat)

ADVANTAGES

Rapid load following capability

Lower cost of fabrication

Robust

High power density

The Proton Exchange Membrane The Proton Exchange Membrane (PEM)(PEM) system allows compact system allows compact designs and achieves a high energy designs and achieves a high energy to weight ratio.to weight ratio.

Efficient

In comparison, the internal compaction motor has an efficiency of

about 15%.

HIGH Manufacturing

Cost

Heavy Auxiliary Equipment

Needs Pure Hydrogen

Complex Heat and Water

Management

Start and stop conditions induce drying and wetting, which contributes to membrane stress. If run continuously, the stationary stack is

estimated at 40,000 hours. Stack replacement is a major expense.

Disadvantages

-It conducts the electrons that are freed from the hydrogen molecules so that they can be used in an external circuit.

-It has channels etched into it that disperse the hydrogen gas equally over the surface of the catalyst.

Basic Elements of PEMFC

Anode

-has channels etched into it that distribute the oxygen to the surface of the catalyst.

-conducts the electrons back from the external circuit to the catalyst, where they can recombine with the hydrogen ions and oxygen to form water

Cathode

Anode Reaction Cathode Reaction

H2 → 2H+ + 2e- O2 + 4H+ + 4e- → 2H2O

Basic Elements of PEMFC

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Electrolyte

-This specially treated material, which looks something like ordinary kitchen plastic wrap, only conducts positively charged ions.

- The membrane blocks electrons.

Catalyst

- It is usually made of platinum powder very thinly coated onto carbon paper or cloth.

- The catalyst is rough and porous so that the maximum surface area of the platinum can be exposed to the hydrogen or oxygen.

- The platinum-coated side of the catalyst faces the PEM.

How a PEM Fuel Cell Works?

How a PEM Fuel Cell Works?

How a PEM Fuel Cell Works?

How a PEM Fuel System Works?

Fuel Cell Stack

PEM Fuel Cell Applications

The first viable The first viable electric alternative to electric alternative to

the internal the internal combustion engine combustion engine

for vehicles, e.g. for vehicles, e.g. cars, motorbikes, cars, motorbikes,

buses, locomotives, buses, locomotives, forklifts, light aircraft forklifts, light aircraft

and UAVs.and UAVs.

Portable generation systems for domestic, industrial, military and

maritime application

Small scale power packs for remote, unattended and

military application

On board On board auxiliary power auxiliary power units (APUs) for units (APUs) for

land and air land and air transportationtransportation

Decentralized Decentralized power generation power generation for industrial and for industrial and

domestic domestic applicationsapplications

General battery replacement/displacement.

The Current PEM Market

63%

6%10%

2%Portable

Niche Transportation

Light Duty Devices

Large Stationary

3%Buses 16% Small Stationary

Total Number of PEM Units Installed Globally By Application