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:
Being carbon neutral by 2050.
Expanding to meet the world’s transportation demands without
expanding the emission of greenhouse gases.
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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[1].
Commercial aircraft are 70% more fuel efficient today than they were
40 years ago[2].
In the United States
The Airlines
Three key points are being stressed by aviation officials and airlines.
1. U.S. carriers have reduced fuel burn significantly in this decade.
2. The industry is eagerly exploring alternative fuels.
3. 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[3], 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.
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.
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.
Continental Airlines with Boeing and GE Aviation has conducted a biofuel demonstration flight 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.
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Switchgrass
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.
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.
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 RollsRoyce – and other companies. According to Airbus, each company will
invest time and intellectual property into developing and testing a biofuel “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
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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.
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%.
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
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of environmental impact and fuel burn, Aviation Week reports. Boeing
has a similar program underway.
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.
Currently, the U.S. military is 1.5% of U.S. fuel use, and consumes
340,000 barrels of oil a day.
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.
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.
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.
South African Airways has been using a similar blend of half
synthetic/half conventional fuel in its commercial aircraft for years.
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.
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
[1] Air Transport Association (ATA)
[2] Federal Aviation Administration (FAA)
[3] Even with the planned cutbacks, the U.S. carriers’ fuel bill is expected to
exceed $60 billion in 2008.
Other Resources:
Climate Change State of Knowledge
For more information:
The Boeing Company
Airbus