PREAPRED BY:

ABHINAV KUMAR

0901213308

CHEMICAL ENGINEERING DEPARTMENT

Different types of Fuel cell

ContentsContents

History of fuel cell

Fuel cell introduction

Overview of PEMFC

PEMFC basis

ContentsContents

Basic Elements in a PEMFC

How PEM Fuel Cell Works

Comparison with IC engine and battery

PEM FUEL CELL Applications

The Current PEM Market

Part IIPart II

History of PEM Fuel CellHistory 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.

Fuel cell introductionFuel cell introduction

A fuel cell is an electrochemical

conversion device.

They are being publicized as a source of

energy of tommorow.

Different Types of Fuel CellDifferent 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 Proton Exchange Membrane in the form of a thin, permeable sheet.

Proton Exchange Membrane FC Proton Exchange Membrane FC

Description Description

Concept Concept

- consists of an 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

A PEM fuel cell uses hydrogen and oxygen to produce electricity .

-A thin, solid, organic compound known as Nafion.

-the consistency of plastic wrap and about as thick as 2 to 7 sheets of paper.

-This membrane functions as an gateway, allowing only +ive ions (protons) to pass through it.

Fuel cells are operationally equivalent to a battery.

For automotive applications hydrogen is the fuel choice.

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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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 of power.

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

Basic Elements of PEMFCBasic 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 PEMFCBasic Elements of PEMFC

Electrolyte

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

- The membrane blocks electrons.

-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.

- 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 System Works?How a PEM Fuel System Works?

Membrane

SystemOutput

heatEff.

ElectricalEff.

OperatingTemp.

50 - 100°C

70-80%

Proton exchange membrane nafion mainly

.01KW – 250 KW

70 – 90%(low grade waste heat)

PEMFC

ADVANTAGES

Rapid load following capability

No Internal combustion 

Zero emission

High power density

  The Proton Exchange Membrane (PEM) The Proton Exchange Membrane (PEM) system allows compact designs and achieves a system allows compact designs and achieves a high energy to weight ratio.high energy to weight ratio. In comparison, the internal compaction motor has an efficiency of about 15%. More then internal combustion engines.

Energy Efficient

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.

DisadvantagesDisadvantages

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

the internal the internal combustion engine combustion engine for vehicles aircraft for vehicles aircraft

and UAVs.and UAVs.

Portable generation systems for domestic, industrial 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 transportation.transportation.

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

domestic domestic applications.applications.

.PEM Fuel Cell Applications

PEM Fuel Cell REFERENCES

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Free Yourself!BREAK the petroleum chain!