Fuel Cell Technology: Experimental Analysis and Review of Types

This assignment is a comprehensive report on fuel cell technology, encompassing both a literature review and an experimental analysis. Part A reviews five main fuel cell types (Direct Methanol Cell, Zinc Air Fuel Cell, Protonic Ceramic Fuel Cell, Phosphoric Acid Fuel Cell, and Microbial Fuel Cell), detailing their reaction chemistry, operating temperatures, cell designs, and electrode materials. Part B presents an experimental report using the Cussons P9040 Demonstration Unit, focusing on the characteristics and efficiencies of a PEM fuel cell. The experimental setup, procedure, and results, including graphs of current vs. voltage and power, are detailed. The report also explores the effect of load on the rate of response, current efficiency, and system efficiency, along with calculations and analysis of the fuel cell's performance. The report thoroughly analyzes the fuel cell's performance under varying load conditions and determines the overall system efficiency.

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ABSTRACT
This demonstrated project adds to the information base in the zone of energy units in stationary
applications, hydrogen powered vehicles, edge-of-matrix applications for energy units, and
energy stockpiling in blend with energy units. The project showed that it is in fact doable to meet
the entire transport energy needs of an ordinary upstate London, UK. The energy component that
has been studied previously performed well over the 1-year exhibition period as far as
accessibility also, effectiveness of transformation from chemical energy (propane) to electrical
energy at the energy unit yields terminals. Another quality of energy unit execution in the show
was the low necessities for support and fix on the energy component. The undertaking revealed
another and essential establishment thought for hydrogen fuel cells. Regardless of good in
general specialized execution of the power module and the entire energy framework, the project
demonstrated that such a framework is financially plausible as contrasted with other industrially
accessible innovations, for example, diesel combustion motor generators.

PART A
INTRODUCTION
A fuel cell refer to an electrochemical device that basically combines oxygen and hydrogen in
order to ensure that there is production of electricity, heat and water as the by-products. For
whatever length of time that fuel is provided, the energy component will keep on producing
power. Since the change of the fuel to vitality happens by means of an electrochemical
procedure, not ignition, the procedure is spotless, calm and exceedingly productive – a few times
more proficient than fuel consuming. No other vitality age innovation offers the mix of
advantages that energy components do. Notwithstanding low or zero outflows, benefits
incorporate high proficiency and dependability, multi-fuel capacity, siting adaptability,
sturdiness, versatility and simplicity of upkeep. Energy units work quietly, so they decrease
commotion contamination and also air contamination and the waste warmth from a power
module can be utilized to give high temp water or space warming for a home or office.
Direct Methanol Cell
This kind of the cells is basically the same as those of the PEM cell. This is because they both
have an application of the membrane as the key polymer of the electrolyte. In this kind of the
fuel cell however; the anode catalyst itself draws the hydrogen from the liquid methanol. This
kind of the operation leads to the elimination of the use of the fuel reformer. The operation of
this kind of the cell is expected at efficiencies of 40%.This kind of the operation is achievable at
the temperature range of 120-190 F.The identified range is actually very low and this makes this
type of the fuel cell less attractive for any tiny and mid-sized areas or applications tasks. They

can therefore be used in the process of powering on the laptops and cellular phones. The higher
the temperature the higher the efficiencies. Most of the companies that deal with this kind of the
cell have been exploiting this kind of the direct proportional relationships. The military normally
use the products of the DMFC cells in the powering of the electronics in the field.
Zinc Air Fuel Cell
In the original sample of the zinc/air fuel cell, there is normally gas diffusion electrode, some
elements of the mechanical separators and the zinc anode separated by the electrode. The most
commonly known characteristics of the GDE are that the membrane is actually permeable. This
property allows for the passage of the oxygen. After the oxygen has been converted into the
byproducts of the water and the hydroxyl ions, these ions of the hydroxyl will travel through an
electrolyte thereby reaching the zinc anode(Zammit, Staines and Apap 2014). Upon reaching the
zinc anode, it will react with the zinc leading to the formation of the zinc oxide. This procedure
makes an electrical potential; when an arrangement of ZAFC cells are associated, the
consolidated electrical capability of these cells can be utilized as a wellspring of electric power.
This electrochemical procedure is fundamentally the same as that of a PEM power device, yet
the refueling is altogether different and shares qualities with batteries. ZAFCs contain a zinc
"fuel tank" and a zinc icebox that consequently and quietly recovers the fuel. In this shut circle
framework, power is made as zinc and oxygen are blended within the sight of an electrolyte (like
a PEMFC), making zinc oxide. When fuel is spent, the framework is associated with the network
and the procedure is turned around, leaving indeed unadulterated zinc fuel pellets. The key is this
turning around process takes just around 5 minutes to finish, so the battery energizing time hang
up isn't an issue. The main favorable position zinc-air innovation has over other battery advances

is its high explicit vitality, which is a key factor that decides the running span of a battery in
respect to its weight.
Protonic Ceramic Fuel Cell (PCFC)
This is a new type of the fuel cell that is based on the electrolyte material that is ceramic. This
kind of the material exhibits high conductivity of the protons. The conductivity of the protons
takes place as an elevated temperature. This kind of the ceramic share kinetic and the thermal
advantages of the operations the high temperature of almost 700degress celcius.This temperature
is responsible for the molten carbon and the fuel cell of the solid oxide. This has been happening
in the expression of the intrinsic advantages of the proton conduction in the case of the PEM and
also the phosphoric fuel cells(Rus and Tolley 2015). The high working temperature is important
to accomplish high electrical eco-friendliness with hydrocarbon powers. PCFCs can work at high
temperatures and electrochemically oxidize non-renewable energy sources straightforwardly to
the anode. This dispenses with the halfway advance of creating hydrogen through the exorbitant
improving procedure. Vaporous particles of the hydrocarbon fuel are assimilated on the surface
of the anode within the sight of water vapor, and hydrogen iotas are productively peeled off to be
consumed into the electrolyte, with carbon dioxide as the essential response item. Furthermore,
PCFCs have a strong electrolyte so the layer can't dry out as with PEM energy components, or
fluid can't spill out as with PAFCs.
Phosphoric Acid Fuel Cells (PAFC)
Phosphoric acid fuel cells are commercially available in the today world. There has been
installation of over hundreds of this kind of the fuel cell in 19 nations. This fuel cell find its
application in the hotels, hospitals, nursing homes, utility power plants and schools.The4

efficiency of the generation of the electricity by this kind of the fuel cell is 40% efficiency and
this is equivalent to almost 85% of the stream. PAFCs create power at over 40% effectiveness -
and almost 85% of the steam this energy component produces is utilized for cogeneration - this
thinks about to about 35% for the utility power lattice in the United States. Phosphoric corrosive
power devices utilize fluid phosphoric corrosive as the electrolyte and work at about 450°F. One
of the principle points of interest to this sort of energy component, other than the about 85%
cogeneration effectiveness, is that it can utilize sullied hydrogen as fuel. PAFCs can endure a CO
centralization of about 1.5 percent, which widens the selection of energizes they can utilize. In
the event that fuel is utilized, the sulfur must be expelled
Microbial Fuel Cell (MFC)
Microbial fuel cells use the catalytic reaction of the microorganism including the bacteria that
assist in the conversion of organic material into the fuel itself. The commonly broken down
organic matter include waste water, glucose and acetate. Encased in without oxygen anodes, the
natural mixes are devoured (oxidized) by the microscopic organisms or different
microorganisms. As a feature of the stomach related process, electrons are pulled from the
compound and led into a circuit with the assistance of an inorganic arbiter. MFCs work well in
gentle conditions in respect to different kinds of energy components, for example, 20-40 degrees
Celsius, and could be fit for delivering over half proficiency. These cells are appropriate for little
scale applications, for example, potential medicinal gadgets energized by glucose in the blood, or
bigger, for example, water treatment plants or bottling works delivering natural waste that could
then be utilized to fuel the MFCs(Ortega, Perez, Nicklasson and Sir 2013).
PART B, Experimental write up:

Introduction:
In this experiment desk top mounted Cussons P9040 system is used to study the characteristics
of a fuel cell. The system consists of a fuel cell stack comprising 10 cells set on top of a control
unit. The type of fuel cell used is PEM with an efficiency of around 40%. The maximum output
from stack is 12W. The control unit includes a loading system consisting of an ammeter,
voltmeter and variable rheostat. No power supply is required for the system; only Hydrogen flow
at approx. 160 cc/min will be needed. The whole set up is shown in the figure below.
Fig: Experimental set up for investigating fuel cell performance (Cussons P9040 demonstration
unit)
Apparatus:
Cussons P9040 demonstration unit consisting of,
 Fuel cell stack (comprising 10 PEM fuel cells with 10-12 W output at 6V DC)
 Control unit which consists of following instrumentation,
i) Voltmeter for displaying voltage.
ii) Ammeter for displaying current.

iii) Pyrometer, switchable to show inlet and outlet air temperatures.
iv) Rheostat for adding variable resistance in order to perform load test on fuel cell.
v) Selector switch for selecting the test which needs to be performed.
vi) Sockets for data output.
 Metal Hydride Hydrogen storage bottle
 Hydrogen flow meter with control valve for setting Hydrogen flow (fixed on the right
side of control unit)
 Solenoid valve which is fixed on top of control unit and helps the system to operate in
load following mode (when operating in this mode Hydrogen consumed is directly
proportional to the power used)
Procedure:
Starting of Stack:
 Small quantity of distilled water was sprayed through the air holes present on top of
control unit for humidification purpose so that fuel cell doesn’t get dehydrated under
load.
 Pipe from the outlet of stack was removed and hydrogen gas was passed from the storage
bottle at the pressure of 2 psi (pound-force per square inch) and flow rate of 100 cc/min
(cubic centimetres/minute) for about 2-3 seconds.
 The selector switch was put to characteristic option.
 Hydrogen flow was set to approx. 75 cc/min and rheostat was adjusted to get the current
value of 0.5-0.8A. Fuel cell was run at this condition for around 10 minutes.
 Now the Hydrogen flow rate was adjusted to 140 cc/min.

 The pipe on the outlet was inserted back. The system was now running, and cell
characteristics could be test.
Testing cell characteristics:
 The system was allowed to warm up for 5-10 minutes and outlet pipe was removed then.
The flow rate for Hydrogen was set to 160 cc/min and pressure to 1.5-2 psi. The outlet
pipe was put back inside.
 The load was set to minimum by turning the control knob fully anticlockwise.
 Open circuit voltage was recorded by turning off the selector switch for few seconds.
 Selector switch was set back to cell characteristic option and values for voltage, current
and Hydrogen flow rate were recorded.
 The load was increased slowly and voltage, current and Hydrogen flow was recorded for
each unit increase.
 Now the selector switch was set to “characteristic with fan” option and all the above steps
were repeated. Selecting “characteristic with fan” allows more air (oxygen) get inside the
cell hence increasing the power output.
 Cell characteristics were analysed by plotting graphs for current against voltage, current
against power and Hydrogen flow rate against power.
 Current efficiency and system overall efficiency was determined.
Effect of load on rate of response test:
Some applications such as automotive vehicles have quickly changing power demands. In such
cases knowledge of the response time of the cell for varying load is essential. This can be studied

by changing the load demand on the cell. Following steps were carried to study the effect of load
on rate of response.
 The system was already running and solenoid was connected (with this set-up change in
load changes Hydrogen flow accordingly). The load was set to maximum by rotating
control knob full clockwise and Hydrogen flow was recorded.
 The load was quickly changed to minimum and time taken for Hydrogen flow to reach a
steady value was recorded.
 Now the above step was repeated by changing the load quickly from minimum to
maximum.
 Graph was plotted for load against response rate and result was analysed for effect of
load on rate of response.
Stopping of stack:
 Selector switch was set to cell characteristic position.
 Load was increased to maximum and Hydrogen flow was stopped.
 Once the voltage reached to zero selector switch was put to off position.
 Hydrogen supply was cut off.
Current and thermal efficiency Calculations:
Current efficiency:
There are always some faradaic losses in fuel cells for instance practically electrolyte
membrane is not always perfectly insulating due to which some of the electrons leak through
the membrane and reach directly to cathode instead of following the external path. Due to

these losses observed (experimental) current is always less than the theoretical current
(maximum current at a particular flow rate under ideal operating conditions). The ratio of
theoretical current to the observed current gives current efficiency.
Current efficiency (%) = Observed current/Theoretical current × 100
Where theoretical current can be calculated using Faradays law,
Since, 1 g mol = nF Coulombs
Where, n (number of electrons) = 2 for Hydrogen fuel cell
And F (Faraday number) = 96,500 Coulombs
Since, 1 g mol of Hydrogen at STP (standard temperature and pressure) = 22.4 litres
So, 22.4 litres of Hydrogen at STP = 2 × 96,500 Coulombs = 193000 Coulombs
Or alternatively,
22.4 litre/sec of Hydrogen flow rate = 193000 Ampere
1 litre/sec of Hydrogen flow = 193000/22.4 Ampere = 8616.07 Ampere
Since in our case flowmeter is showing flow rate in cc/min and 1 cc/min= 0.0000167
litre/sec
So converting cc/min to litre/sec we get,

Theoretical current = [flow rate (in cc/min) × 0.0000167] × 8616.07
Ampere
Theoretical current = flow rate (in cc/min) × 0.143 Ampere
Thermal efficiency (overall efficiency):
Similarly, theoretical power (power delivered to the external load in the absence of internal
resistances) is different from measured power ( the actual power delivered in the presence of
internal resistances) . We can determine theoretical power of fuel cell by converting calorific
value of Hydrogen to joule.
Since, 1 g mol of Hydrogen = 68,300 calories
Also we know, 1 g mol of Hydrogen at STP = 22.4 litres
So, 22.4 litres of Hydrogen = 68,300 calories
Which gives, 1 litre of Hydrogen = 68,300/22.4 = 3049.11 calories
And 0.239 calories = 1 Joule
So, 1 litre of Hydrogen = 3049.11/0.239 = 12757.78 joules
Or 1 litre/sec of Hydrogen flow = 12757.78 watts
Since we have flow rate in cc/min, and 1cc/min = 0.0000167 litre/sec
Converting cc/min to litre/sec we get,