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HYDROGEN
FUEL
Hydrogen
is considered an ideal energy carrier in the near future.
It
can be produced from water by using a variety of energy sources, such as solar,
nuclear and fossils, and it can be converted into useful energy forms
efficiently and without detrimental environmental effects.
The
only by-product is water or water vapour (if air is used for flame combustion of
hydrogen, small amounts of NOx are produced).
When
solar energy, in its direct and/or indirect forms, is used to produce hydrogen
from water, both the primary and secondary forms of energy become renewable and
environmentally compatible, resulting with an ideal, clean and permanent energy
system… the Solar Hydrogen Energy System.
Hydrogen
can be used in any application in which fossil fuels are being used today, with
sole exception of cases in which carbon is specifically needed. Hydrogen can be
used as a fuel in furnaces, internal combustion engines, turbines and jet
engines, even more efficiently than fossil fuels (i.e. coal, petroleum and
natural gas).
Automobiles,
trucks, buses, trains, ships, submarines, aeroplanes and rockets can run on hydrogen.
Hydrogen
can also be converted directly to electricity by the fuel cells with a variety
of applications in transportation and stationary power generation.
Metal
hydride technologies offer a variety of applications in refrigeration, air
conditioning, hydrogen storage and purification. Combustion of hydrogen with
oxygen results in pure steam, which has many applications in industrial
processes and space heating.
Moreover,
hydrogen is an important industrial gas and raw material in numerous industries,
such as computer, metallurgical, chemical, pharmaceutical, fertilizer and food
industries.
The
hydrogen industry has an enviable safety record spanning more than a
half-century. Any fuel is hazardous and needs due care, but hydrogen's hazards
are different and generally more tractable than those of hydrocarbon fuels. In
the vast majority of cases, leaking hydrogen, if lit, will burn but not explode.
However,
in the rare cases where it might explode, its theoretical explosive power per
unit volume of gas is 22 times weaker than that of petrol vapour. It is not,
as has been claimed, "essentially a liquid or gaseous form of
dynamite."
Hydrogen
is four times more diffusive than natural gas, or 12 times more than petrol
fumes, so leaking hydrogen rapidly disperses up and away from its source.
If
ignited, hydrogen burns rapidly with a non-luminous flame that can't readily
scorch you at a distance, emitting only one-tenth the radiant heat of a
hydrocarbon fire and burning 7% cooler than gasoline.
Although
fire fighters dislike hydrogen's clear flame because they need a viewing device
to see it in daylight, victims generally aren't burned unless they're actually
in the flame, nor are they choked by smoke.
One
videotaped test of a standard passenger car compared a hydrogen leak with a
petrol leak.
In
the first test, a hydrogen leak was created, assuming a very unlikely triple
failure of redundant protective devices. The leak discharged the entire 1.54-kg
hydrogen inventory of the fuel-cell car, but the resulting vertical flame plume
raised the car's interior temperature by 1-2C° (0.6-1.1 F°). The passenger
compartment was unharmed.
In
the second part of the test, petrol leaked from a 1.6-mm (1/16") hole in
the fuel line. The resulting explosion gutted the car's interior and would have
killed anyone trapped inside. Because the hydrogen-leak test didn't damage the
car, the petrol part of the test was conducted using the same car. Had the
petrol portion of test been done first, a second car would have been required
for the hydrogen leak test.
Contrary
to a popular misunderstanding, these safety attributes of hydrogen actually
helped save 62 lives in the 1937 Hindenburg disaster.
An
investigation by NASA scientist Dr. Addison Bain found that the disaster would
have been essentially unchanged even if the dirigible were lifted not by
hydrogen but by non-flammable helium, and that probably nobody aboard was killed
by a hydrogen fire. (There was no explosion.)
The
33 passengers who died were killed by jumping out or by the burning diesel oil,
canopy, and debris… the cloth canopy was coated with the primary chemical
components of rocket fuel which ignited due to discharge of static electricity
when the zeppelin docked. The other 62 survived, riding the flaming dirigible to
earth as the clear hydrogen flames swirled harmlessly above them.
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hf
HYDROGEN FUEL - Not
Just Hot Air
Larry Burns doesn't
look like an evangelist. It's impossible to imagine this urbane engineer on
street corners in a sandwich board declaring, "... the hydrogen economy is
coming."
However, when he
says it, in his quiet and precise tones, he has the power to make converts. To
turn faithless rev-heads high on fumes into hydrogen true believers. To persuade
petro-holics that water, the only "waste" product of fuel cells, could
become their favourite tipple.
In January 2005, General Motors
Vice-President for Research, Development and Planning was at the Detroit motor show telling the world press about
Sequel, the car giant's new hydrogen fuel cell vehicle.
It's a concept that
represents the next stage in what GM chairman Rick Wagoner says will be the auto
industry's "moon shot"; the ambitious goal of replacing petrol as
first choice for the global fleet.
Alone among car
companies, GM has set a target of 2010 for a workable version of the technology
that delivers on ability and bottom line. And Burns is GM's hydrogen prophet.
"Our goal is to
have a fuel cell propulsion system, designed and validated, that would give you
the performance required and also that would be comparable in cost when you're
building about 1 million a year," says Burns.
With the price of
oil making headlines daily, it's not the prospect of dry wells that worries
Burns, but an uncertain, stifling future.
"We're in the
camp that feels there's plenty of petroleum for a long time on the planet, but
that's not the issue. It's the volatility around that supply that's the
issue," he says.
"So there's a
reason why we set that target. We believe the industry is extremely vulnerable
relative to its ability to grow.
"Not that
there's demand issues with growth, only 12 per cent of the people in the world
own a car.
"But could that
growth be capped by an energy issue, an environmental issue, a safety issue or a
congestion issue?"
Climate warming,
energy independence, political instability or rapid growth in China, in the huge
Cobo Centre Hall where the motor show is being held, car companies have already
responded with a swag of hybrid cars that combine petrol engines with electric
motors for efficiency.
The success of the
few models already on sale has taken the industry by surprise.
But Burns says
hybrid maths just doesn't add up.
"Let's say
tomorrow morning we woke up and every one of the cars in the US, 220 million
cars and trucks, had a hybrid system in it that could make it 25 per cent more
efficient," he supposes.
"How many years
do you think the US could go forward before we started consuming more petrol
that we consume today?
"Six."
He explains:
"Vehicle miles travelled correlate directly with economic growth, which is
running at 3 per cent to 4 per cent a year. Compound that over six years and you
get 25 per cent, wiping out all your hybrid gains."
In engineering terms
too, hybrids have fundamental problems.
"A hybrid adds
hardware, batteries, electric motors, power electronics, and things to the car
which have mass, package requirements and cost implications. Hydrogen fuel cells
take you in the other direction. They're simpler, and we think they have the
chance of solving the problem."
The principle, at
least, has been around a long time, after being discovered in 1839. Fuel cells
were used by NASA in the Apollo projects and today there are even fuel cell
mobile phones.
But fuel cells for
cars seem forever around the corner, with cost a major hurdle. Vehicles already
running around the US and Japan represent small-scale, pre-commercial trials.
Burns says huge
production gains remain to be released.
"There's
one-tenth as many moving parts in a fuel cell propulsion system (FCPS) as there
is in an internal combustion engine system," he explains. "That's a
huge opportunity for cost competitiveness.
"Furthermore,
the parts that you do have in an FCPS have very simple geometry, it's more like
making CDs or video cassettes than the traditional heavy-duty engine
manufacturing line.
"So what you
have working for you is a quite different manufacturing system that wouldn't be
as capital-intensive and a design that has one-tenth as many moving parts.
There's nothing in the pile of molecules that makes up a fuel cell propulsion
system that says it should cost more."
Based on an
equivalent petrol engine, GM says its target is $US50 ($65) per kilowatt. Burns
reckons the Sequel, which uses fourth-generation fuel cells, comes in at around
$US500 ($650) a kilowatt.
But only six years
ago it was $US5000 and the example of chip power in the computer industry shows
how rapidly gains can be made. Burns can smell success.
"We have a
vision for the design; we know how you would take your $US50 per kilowatt and
allocate it to every part and subsystem in that design. And we have people
working very hard to meet those cost and durability targets ... and nobody is
saying it can't be done."
Take away
feasibility and the sceptics raise other objections: how will we produce enough
hydrogen? What about the cost of building thousands of refilling stations? And
safety... remember the Hindenburg airship disaster?
Burns has answers
for them, too. Hydrogen is already being produced in large quantities, he says,
and the sources are many and varied, coal, natural gas, any source of
electricity. Even petrol.
He quotes a gas
specialist company called Air Products, which has calculated that enough
hydrogen is made around the globe to fuel 200 million fuel cell vehicles... every
day!
"You don't have
to invent something to know how to create hydrogen, that's well-known technology
given the quantities being produced," Burn says.
"This industry
apparently handles it safely because I never hear about a hydrogen accident.
There's a lot of safety knowledge out there."
And Burns demolishes
the infrastructure argument like this: "Suppose you put hydrogen stations
in the 100 largest US cities (representing 70 per cent of the population) so
that none is more than 3.2 kilometres away, plus every 40 kilometres on all
interstate highways. That equals 12,000 stations across the US.
"Companies like
Shell, Exxon Mobile, Chevron Texaco suggest those stations would cost about $US1
million each, that's $US12 billion," Burns continues. "If you were
going to build the Alaskan pipeline today it would cost $US25 billion.
"The Alaskan
pipeline is one sliver of the petroleum infrastructure in the US."
Hydrogen could be
trucked from refineries to the stations or made at the station itself from
natural gas or water and electricity.
"We believe
$US12 billion is a pretty good option for the US Government to buy to have an
alternative to petroleum. When you consider what it costs to keep the Iraq war
going, it's not an astronomical number."
Petrol may be around
a long time, 750 million cars depend on it, but "hydrogen has to become the
dominant technology".
Governments will
need to get the hydrogen wheels rolling, perhaps with favourable tax structures,
certainly with codes and standards. But the market must steer the course, Burns
says.
"Governments
can't subsidise shifts of that magnitude and certainly industries can't sell
products below cost to make that happen. It really has to be a market
dynamic."
So there's no point
finding favour with a small circle of Hollywood early-adopters who can afford to
care. Here, for Burns, is the biggest challenge: widespread consumer acceptance.
A hydrogen fuel cell
car will be better, possibly even more affordable, but it will be different,
without the sensual qualities of internal combustion.
The solution lies in
software.
"If you want
the sound of a car accelerating we can just put it through the sound system, the
thing that makes it feel like a Porsche instead of a VW is going to be
software and you just program that in."
And horsepower has
lost some of its pull.
"For a lot of
kids growing up today that's just not what it is. The technology is the computer
and mobile telephone and they're more environmentally sensitive due to the education
system. That could accelerate this change."
