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Aerospace
and Greenhouse Gases –
Background Brief
“Man’s
battle with nature has been won. Whether we like it or not, we are
now burdened with the administration of the conquered territory.
Nature reserves, landscapes, townscapes: they will all be wantonly
destroyed, to the ultimate ruin of man, or they must be deliberately
planned to serve his needs” – Ove Arup, one of the 20th
century’s great engineers.
“What’s the use of curing cancer if
we destroy the planet?” J. Craig Venter
Air Traffic Control (ATC) improvements
provide the easiest short term initiative to dramatically reduce
greenhouse emissions from transport aircraft.
Aviation’s Goal

Aerospace has always been a technology
leader, and together with the air transport industry has taken a lead in the
reduction of greenhouse gases. On April 22, 2008, the
world’s airlines, airports and major aircraft manufacturers came
together to announce a goal of:
The announcement was made in Geneva
and Washington, D.C.
New technology has the potential to
provide:
- Air
Traffic Control – a 15% to 20% reduction;
- Airframe
and engine advances – 15% to 25% reduction;
- Airport
efficiencies – 10% to 15% reduction.
The reductions can be cumulative.
They cannot occur overnight and will take time to phase in, but they
are feasible. It’s a matter of application rather than research.
Air Traffic Control improvements are
the low hanging fruit currently difficult to pick, due to politics in the
United States and Europe.
The “carbon neutral” goal will require
research and may well need technological breakthroughs that would
then also be available to other industries.
Historic Reductions
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Between 2000 and 2006, U.S.
airlines reduced fuel burn (and thus greenhouse gas emissions)
by 4% while carrying 12% more passengers and 22% more cargo.
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Commercial aircraft are 70% more
fuel efficient today than they were 40 years ago.
In the United States
The Airlines
Three key points are being stressed by
aviation officials and airlines.
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U.S. carriers have reduced fuel burn
significantly in this decade.
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The industry is eagerly exploring
alternative fuels.
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A “Next Gen” satellite based ATC
system is the best way to rapidly enhance aviation’s environmental
efficiency.
Air Traffic Control Improvements
In 2007, the airlines spent $40 billion on
fuel,
of which $9 billion was wasted through delays. That means their
greenhouse gas emissions were 22% higher than was necessary (FAA
Forecasting Conference, March 2008).

Alternate Fuels
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Planes need fuel that does not freeze at high altitudes
and which is uniform the world over. As there are some 19,000
turbine powered
transports flying around the world, the best solution would be a
“drop in” replacement for existing fossil based jet fuel that emits
substantially less carbon. This is a major challenge.
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Virgin Atlantic has flown a Boeing 747 from London to Amsterdam
using 5% coconut oil to demonstrate a bio-fuel that could take high
altitude, cold temperatures. But the short flight reportedly used
oil from 150,000 coconuts, so there is unlikely to be enough coconut
production to fulfill aviation’s fuel needs.
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As part of a research project, Airbus has flown an A320 with one of
its engines powered by an alternate fuel generated from natural gas
and formulated to produce less greenhouse gas.
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Continental Airlines with Boeing and
GE Aviation will conduct a bio-fuels demonstration flight in the
first half of 2009 using one of the airline’s 737 NGs. Boeing has
cited algae, babassu nuts, halophyte plants, jatropha plants and
switchgrass as possible sources for the fuel, which could comprise
as much as 50% of the blend powering one of the 737’s two engines.

Switchgrass
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Airbus also is working with Honeywell to develop an Auxiliary Power
Unit (APU) in the form of a fuel cell which would be powered by
hydrogen. The exhaust would be water, which could be used in the
aircraft’s sanitary systems. APUs are used to provide ground power
for air conditioning and aircraft services, for engine starting, and
for emergency systems power in flight.
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Ethanol – the currently popular automotive bio-fuel – will not work
for aircraft, as it typically freezes at 36,000-ft., which would
create a safety problem. Also, ethanol competes for corn as a
source of food, and according to some reports, consumes more energy
in its production than it saves as an alternative fuel.
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Airbus and Honeywell International, Inc. recently announced their
plans to develop a bio-fuel “that by 2030 could satisfy nearly
one-third of the worldwide demand from commercial aircraft without
affecting food supplies.” According to the Wall Street Journal,
they plan to produce fuel from vegetation and algae-based oils that
do not compete with existing food production or land and water
resources. The Airbus/Honeywell team includes JetBlue and
International Aero Engines – largely a partnership between Pratt and
Whitney and Rolls-Royce – and other companies. According to
Airbus, each company will invest time and intellectual property into
developing and testing a bio-fuel “that can later be sold to
refiners or others interested in producing it.” “In order to
replace a significant portion of jet fuel with bio-jet, we need to
find something that has much greater yield than the current bio-mass
sources available,” according Sebastian Remy, head of alternative
fuels research programs for Airbus.
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Honeywell also was selected by DARPA (Defense Advanced Research
Projects Agency) last June to develop and commercialize the
production of jet fuel from the same renewable sources for use by
U.S. and NATO military aircraft.

Airbus and Honeywell recently announced their plans to develop a
bio-fuel
The Promise of Bio-fuels
While it’s technically feasible to power
aircraft with bio-fuels today, some technical breakthroughs will be
required before bio-fuels can be produced in the quantities required to
meet the needs of world aviation, i.e. a breakthrough similar to the
enzyme discovered several decades ago that enables soybeans to be turned
into protein rich food digestible by humans.
Improvements in Aircraft Efficiencies
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The next generation of aircraft could reduce fuel consumption, and
thus greenhouse gas production by 10% to 15%.
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All the aircraft and engine manufacturers have research programs
underway in order to improve the efficiency of their products. For
example, Airbus UK recently launched a Next Generation composite
wing project. The program will not only look at wing and aircraft
design, but also will examine how to reduce the overall
environmental impact of the manufacturing process and the factory.
The program provides a fundamental opportunity to re-examine the
configuration of commercial aircraft in order to meet the
increasingly intertwined issues of environmental impact and fuel
burn, Aviation Week reports. Boeing has a similar
program underway.
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A Boeing research center in Spain has
successfully flown the first fuel cell powered aircraft.
United States Air Force Initiatives
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The United States Air Force plans to buy 50% of its fuel from
synthetic domestic sources by 2016.
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Currently, the U.S. military is 1.5% of U.S. fuel use, and consumes
340,000 barrels of oil a day.
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The Air Force goal is to:
- Reduce its dependency on foreign oil.
- Stimulate large scale commercial production of synthetic
fuels.
“Our goal is to drive the development of a market here in the U.S.”
Air Force Assistant Secretary, William Anderson, told the Wall
Street Journal.
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The Air Force is working with aircraft and engine manufacturers,
such as Boeing and Pratt and Whitney. North American synthetic fuel
producers include Rentech, Inc., Baard Energy, and Syntroleum
Corporation. All operate or hope to build synthetic fuel refineries
to feed the military’s growing thirst, the Wall Street Journal
reports.
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Synthetic fuel, according to the Wall Street Journal, which
can be made from coal or natural gas, could cost far less than oil
at its current price (about $130/barrel), if the synthetic is mass
produced.
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South African Airways has been using a similar blend of half
synthetic/half conventional fuel in its commercial aircraft for
years.
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The Air Force has now tested its alternative fuel in a B-52 bomber,
in a C-17 transport, and in a B-1 bomber flying at supersonic speed.
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The process for turning raw carbon sources, such as coal or natural
gas, into usable aviation fuel was developed by German scientists in
the 1920s.

Alternative fuel has been tested in a B-52 bomber
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