Hydrogen: The Alternate, Alternate Fuel
Prashast Pittie
Viterbi School of Engineering, USC
Prashast Pittie is a Junior at the University of Southern California
studying Industrial Engineering. His dream is to drive the Swedish
supercar, the Koenigsegg Agera R around the Nordschleife.
The worldwide phenomena known as the green movement has it hit an all time
high. In order to tackle this phenomenon, automobile manufacturers have started
producing hybrid and electric vehicles. This paper will go into detail on how one
seemingly overlooked alternative fuel in the automobile industry is hydrogen. It
also goes on to explain why hydrogen is currently not used, and also why it
should be developed further in order to be made a viable alternative to gasoline
in the automotive sector. The use of hydrogen fuel cells hasn’t seem to caught on
and even though every manufacturer claims they make a hydrogen powered
vehicle, they are all only one off concept vehicles. This technology needs to be
further developed because it has the potential to completely replace human
dependence on the rapidly depleting fossil fuels.
With massive organizations like Greenpeace and the worldwide media proclaiming the
desperate state the atmosphere and the general environment is in, the average consumer
has become attentive of his or her environmental impact. The major corporations of the
world have used this to their advantage by advertising that their products are in some way
green and help save the environment. However one major industry has taken the brunt of
the beating from the green movement, and this is the automobile industry. Whereas
carmakers were once making big and powerful dream machines, they have now started
producing small fuel-efficient cars because of their rising demand. Because of this rising
demand for more fuel-efficient vehicles (caused by the rise in fuel prices), automobile
manufacturers have started the research and development of engines using alternative
forms of fuel, the most popular being hybrid and electric cars. However one under
developed technology seems to be the use of fuel cells. A hydrogen fuel cell powered
engine can be up to 25% more efficient that a regular gasoline powered engine while
providing almost zero emissions [1]. This doesn’t mean that consumers have to give up
on the power of an engine because some hydrogen-powered engines are considered to be
upwards of 15% more powerful than a similarly sized gasoline engine [2]. These statistics
show that if developed and exploited, this technology has the potential to replace the
dependence on fossil fuels for powering cars.
Hydrogen as a fuel
Hydrogen traditionally has been used as rocket fuel. This is because when burned in air,
hydrogen gives out massive amounts of energy that can be harnessed as power to move
the rocket. However there are two ways in which hydrogen can be used to power
automobile engines. The first is the hydrogen internal combustion engine and the second
is the hydrogen fuel cell.
Hydrogen internal combustion engine
The hydrogen internal combustion engine is exactly like a regular gasoline engine.
Instead of the gasoline mixed with air that is used as fuel, a mixture of hydrogen and air
is used. The hydrogen is burned in the presence of air to give out heat, which is converted
to mechanical energy that is used to move the car, and water. There are traces of other
gasses that are also formed during this reaction and given out as the exhaust. A regular
gasoline engine can be made to use hydrogen as fuel with minimum modifications to its
components.
This engine was first designed and used in Jean Joseph Etienne Lenoir’s Hippomobile
(Figure 1) in 1860. This was also actually one of the first internal combustion engines
ever used. The hydrogen he obtained to power the engine was created by the electrolysis
(the splitting up into its components) of water [3]. However this engine is vary sparingly
used today, primarily by people who want to do research to see how fuel-efficient
hydrogen can be.
Hydrogen fuel cell
The hydrogen fuel cell is relatively more
common (as opposed to the hydrogen
internal combustion engine) and it has a
much simpler concept behind it. When
used to power a car, however, the fuel cell Figure 1: Lenior's Hippomobile
needs to be mated with an electric motor.
Instead of hydrogen burning with air, in a Source: http://www.xtimeline.com/evt/view.aspx?id=30994
fuel cell hydrogen combines with pure
oxygen to form water and electricity. This is the reverse of electrolysis. The electricity
generated is sent to the electric motor that converts it to mechanical energy, which
eventually makes the car move [4].
The first fuel cell was created in 1839 by a British lawyer whose the name was Sir
William Grove. He discovered the principle by accident during an electrolysis experiment
and his device came to be known as a ‘Gas Battery’. It wasn’t until 1950 that further
development of the fuel cell took place. A chemical engineer named Francis Bacon made
significant advancements that made the fuel cell an efficient source of energy [5].
Disadvantages of hydrogen as a fuel
Even though pound for pound hydrogen contains three times as much energy as natural
gas, there are still some issues with using hydrogen as a fuel. The three major
disadvantages of hydrogen are production, storage and distribution. [6]
Production of hydrogen
Even though the United States uses 10 million tons of hydrogen every year for various
industrial purposes, if a majority of the cars were to switch to fuel cells, another 10
million tons will need to be produced. The trick here is to produce this amount of
hydrogen in an efficient and environmentally efficient way. At present most of the
hydrogen produced is from natural gas or fossil fuels. By putting this natural gas under
high temperature and pressure, it is split into its components of hydrogen and carbon
dioxide (which is a greenhouse gas and bad for the environment). However using fossil
fuels (which could get depleted in the next 10 years or so) to produce clean fuels isn’t
environment friendly. Future methods of production of hydrogen could be either through
electrolysis or with the use of nuclear plants. “Next-generation nuclear power plants will
reach temperatures high enough to produce hydrogen as well as electricity, either by
adding steam and heat to the electrolysis process, or by adding heat to a series of
chemical reactions that split the hydrogen from water. Though promising in the lab, this
technology won't be proved until the first Generation IV plants come on line — around
2020” says Jeff Wise of Popular Mechanics. [6]
Storage of hydrogen
There are three primary forms in which hydrogen can be stored effectively. Firstly
reducing its temperature to nearly freezing can liquefy it and it can be stored like a liquid.
NASA has been using liquid nitrogen to liquefy hydrogen and has been using this
hydrogen as fuel for their space shuttles in this method. This, however, is not very
convenient because the hydrogen has to be stored in big and bulky containers at near
freezing temperatures. Hydrogen can be stored at room temperature in a compressed state
at more than 10,000 psi, but big bulky containers are still required in this case. Finally
hydrogen can be stored in its solid state by using certain compounds known as hydrides.
However as Dan O'Connell, a director of GM's hydrogen vehicle program says "Highpressure tanks are a stopgap until we can develop materials that will allow us to do solidstate storage efficiently."
Distribution of hydrogen
Again there are three ways in which hydrogen is distributed. Firstly it is transported by
trucks in liquid for around the country to where it is needed. Secondly it can be
transported via pipelines, which will require massive infrastructure expansion. And
finally as many of the fuel stations in the United States currently practice, hydrogen can
be produced at the local sight either by electrolysis or by using fossil fuels.
Hybrid vs. hydrogen
The problem with the hybrid car is that it uses gasoline to power its engine. It is very
fuel-efficient because at low speeds the electric motor moves the vehicle, but at regular
freeway speed, both the gasoline engine and the electric motor work in sync to send
power to the wheels. Moreover the electric motor needs to be charged constantly which is
done by the gasoline engine. Therefore this technology seems more like a stepping stone
rather than the solution to a greener planet. The hydrogen fuel cell as explained works on
the principle of a chemical reaction, and because hydrogen burns much quicker and
cleaner than gasoline, fuel cell engines are three times more efficient that hybrid engines
[7]. And as mentioned before, the hydrogen powered vehicle is much more powerful than
its gasoline counterpart. These are major advantages that car companies are looking to
explore. However due to the high initial cost for the infrastructure required to produce
hydrogen, most companies shy away from this technology and only produce concept cars
that they say can be used in the future.
Future use of hydrogen as a fuel
Currently, hydrogen is used very rarely as an alternative fuel. Even though every major
car company has developed some sort of vehicle that runs on a fuel cell, there is only one
manufacturer that has mass-produced a car that uses a fuel cell. The Honda FCX Clarity
(figure 2) is currently the only hydrogen fuel cell car available to consumers. It uses
hydrogen as fuel and produces only water as by products. However this is a normal four
door family car, and its hydrogen tank can be refilled with compressed hydrogen just as a
regular gasoline car [8]. The best part about this car is that unlike an electric car, it
doesn’t take 12 hours to fully recharge, rather it takes just a few minutes at a gas station
to refill it with hydrogen. And again, unlike an electric car its charge doesn’t run out
every hundred miles. It is just like a regular car that is been driven today.
Yes, the Honda FCX is
very expensive, but it is just
a matter of developing
efficient methods of
production and storage of
hydrogen that could drive
prices of the fuel cell
powered vehicle down.
And because the electric
motor that actually runs the
car has just one moving
part, there will be almost
zero maintenance costs.
Figure 2: Honda FCX Clarity
Source: http://www.hydrogencarsnow.com/honda-fcx-clarity.htm
References:
[1] Fuel Cell Vehicles, Consumer Energy Centre, California [Online]. Available:
http://www.consumerenergycenter.org/transportation/fuelcell/index.html
[2] Hydrogen Use in Internal Combustion Engines [Online]. Available:
http://www1.eere.energy.gov/hydrogenandfuelcells/tech_validation/pdfs/fcm03r0.pdf
[3] Fairbanks John W. Engine Maturity, Efiicieny and Potential Improvements. presented at
Diesel Engine Emission Reduction Conference [Online]. Available:
http://www1.eere.energy.gov/vehiclesandfuels/pdfs/deer_2004/session1/2004_deer_fairbanks.pdf
[4 Honda FCX Clarity [Online]. Available: http://automobiles.honda.com/fcx-clarity/
[5] Cook Brian. (2002, December.) Introduction to fuel cells and hydrogen technology.
Engineering Science and Education Journal.
[6] Wise, Jeff. (2006, November.) The truth about hydrogen. Popular Mechanics. [Online].
Available: http://www.popularmechanics.com/science/energy/next-generation/4199381
[7] Onion, Amanda. (2004, November.) Hybrids vs. hydrogen: which future is brighter. ABC
News. Available:
http://abcnews.go.com/Technology/Hybrid/story?id=266883&page=1#.Tti7BWChBXU
[8] Top Gear. (2008.) Episode 7, season 12. Review of Honda FCX Clarity.