Can Airplanes Progress To Fly Without Petroleum?

[KittyWampus]

It seems like a lot of what we depend on in modern life can feasibly be run on alternative fuels/technologies.

But what about flying?

Is there a green version of the airplane?

[MadHound]

1. Theoretically yes,

Electric motors and jam scoops to gather and compress atmospheric gases, then shoot the compressed gas out to propel the plane forward.

Trouble is it would take far more power, and longer batteries than can be generated at this point.

[onehandle]

4. Storing power is Always the biggest problem. My Mac laptop can run 8-9 hours on a charge.

Which is a miracle these days, but is nothing compared to what it would take to power a sustained flight.

They really need to work on battery technology.

[Xithras]

11. Actually, NASA was working on an electric tuboject centered around a superconducting motor.

They had the science down, but were trying to find the funding to build some real world mockups. The big deal about the engines was that their watt-to-thrust ratio was three to four times higher than that found in a conventional fuel burning turbofan.

Their hope was that they could take a single electric turbine generator (which is far more efficient than a jet engine) and produce enough electricity to fully power at least two, and possibly four, electric turbojet engines. In the short term, this would massively reduce the fuel costs associated with commercial flight. Over the longer term, it could spur research into high output industrial fuel cells or other technologies to cut the turbine generator out entirely.

The problem today is that NASA has more good ideas than they have money to fund research into them.

[onehandle]

2. Biofuel is the only feasible alternative that I know of --->

May 20, 2008 Virgin Atlantic and Boeing launched the world's first commercial airline flight on biofuel earlier this year, then Continental Airlines joined the push towards alternative fuels and now Airbus has announced that it will partner with Honeywell, IAE and JetBlue in order to develop a sustainable second-generation biofuel for use in commercial aircraft.

The alternative fuel partnership is being driven by a desire by Airbus to help the aviation sector prosper with less impact on the environment. The companies' joint activity will help develop renewable energy technology to convert vegetation - and algae-based oils into aviation fuels. With much controversy surrounding food-based biofuel crops such as ethanol, the focus will be on non-food-crop biomass fuels. Aside from their environmental benefits, they are believed to provide a better fuel-to-emissions lifecycle than current kerosene. This second-generation bio-jet fuel will be produced using technology developed by Honeywell's UOP, a creator of technology and products for the refining industry. UOP has developed a process to convert biological material into renewable jet fuel that performs identically to traditional fuels while meeting the stringent performance specifications for flight.

Over the last 40 years, the aviation industry has reduced fuel burn by 70%, however the sector is still a major global contributor of greenhouse gas emissions. Sebastien Remy, Head of Alternative Fuels Research Programs for Airbus, said that demand for aircraft fuel is growing and in order to replace a significant portion of that jet fuel with bio-jet, they need to find something that has much greater yield than the current biomass sources available. “Airbus believes that second-generation bio-jet could provide up to 30% of all commercial aviation jet fuel by 2030," Mr Remy said.

http://www.gizmag.com/airbus-commercial-airline-biofuel/9350/

[SidDithers]

3. Probably...

Electric motors could turn propellers. But that would require a ton of electricity. Small nuclear reactor, like on a sub?

Sid

[tech9413]

6. I fly radio control and electric is the future

Brushless electric motors can achieve an efficiency of 85%. An internal combustion engine can at best convert 10% of the energy into usable output.
The problem is energy storage but the developments in the last few years indicate that won't be much of a problem.

[NYC_SKP]

5. Sure. The challenge has to do with "Energy Density".

Since weight is the enemy of efficient flight, whatever fuel is used has to have high Energy Density.

Fossil Fuels have high energy density in the form of stored chemical energy.

Non-fossil chemical fuels, like Ethanol, are good candidates.

Far in the future we may find other high-density chemical fuels or battery/capacitor technologies might improve to allow electrically powered flight on a commercial scale.

And a nuclear powered aircraft is feasible.

:patriot:

[Ready4Change]

17. Also involves desire for speed.

One reason jet liners are so popular is that they are fast. But speed comes at a cost. It takes more fuel to go fast. If people would be willing to add just a few hours to a trip fuel savings could be substantial.

Speed is also one of the big bugaboos of lighter than air travel. While slow, blimps and dirigibles could be very low energy intensive. But then you run into problems with peoples impatience. You also run into competition with the speed and cost of rail or ocean ship transport.

When you get down to it, the high energy demands of fast jet liner travel may be too high for the common Joe/Jane to enjoy in a non-fossil fueled future.

[NYC_SKP]

21. Excellent point. Resistance increases exponentially with speed.

Lighter than air airships would certainly introduce many possibilities, including hybrid electric ethanol run, or hydrogen fuel cell run electrics, with solar PV added to the surface of the airship.

I wonder if slower aircraft with long aspect ratio wings and very high efficiency engines and propeller designs offer hope?

Calling Burt Rutan!

http://www.theage.com.au/ffximage/2008/01/24/VirginGalactic2_wideweb__470x323,0.jpg

[krispos42]

31. But planes fly very high up where the air is thin.

Which negates a lot of the excess consumption. If you fly slower, you have to go down into the denser air to generate enough lift to stay afloat.

[DrCory]

28. I For One Would Love To Travel By Zeppelin Across the Pacific...

To my second home in China. I'm in no hurry though, having learned to enjoy the journey as much as the destination.

[Speck Tater]

7. In theory: YES. In time to do us any good: NO. nt

[ThoughtCriminal]

8. They could use hydrogen

it would probably have to be liquid H2 to have a decent range though. Not as easy to store and pump, but it could work. I suspect that the economics are still not favorable.

[Motown_Johnny]

9. do you mean Petroleum or all fossil fuels? Either way the answer is Yes but it will ne costly.

Here is a link to an article from 1981 which explains some of Germany's progress on synthetic fuels during WW II. (coal based fuels)


http://www.airpower.maxwell.af.mil/airchronicles/aureview/1981/jul-aug/becker.htm




I assume that ethanol based engines are also in aviation's future although I doubt they will ever be as powerful as the engines of today.


I also agree with the post above about fuel cells. Electric engines powered by fuel cells seem likely also.

[glowing]

10. There was an article the other day about the first solar powered airplane.

It used lithium batteries to store the solar power for night flight and the outside had lots of solar panels on it.. It was posted here on DU I believe.

[hobbit709]

22. Very slow with very low payload.

[neverforget]

12. the US Air Force is testing bio fuels

http://www.wired.com/dangerroom/2010/03/air-force-debuts-biofuel-guzzling-warthog/


Air Force Debuts Biofuel-Guzzling Warthog

* By Jason Paur Email Author
* March 30, 2010 |
* 9:09 am |
* Categories: Air Force



For the first time ever, the U.S. Air Force has flown one of its jets powered entirely by a biofuel blend. The flight took place at Eglin Air Force Base in Flordia with an A-10 Thunderbolt II — an aircraft affectionately known as a Warthog — burning a combination of a fuel derived from camelina oil with conventional JP-8 jet fuel.

In a bid to reduce dependence on imported fossil fuels, the Pentagon has been looking to new energy alternatives. Under the Air Force’s current energy plan, the goal is to acquire 50 percent of the domestic aviation fuel from an alternative blend by 2016. Terry Yonkers, the assistant secretary of the Air Force for installations, environment and logistics, said in a statement the goal was to encourage a major shift in the way the service powers its aircraft. “Our goal is to reduce demand, increase supply and change the culture and mindset of our fuel consumption,” he said.

The Air Force is the largest user of jet fuel within the Department of Defense, and plans to have all of the aircraft in its inventory certified to fly using alternative fuels by the end of 2012. The current fleet of aircraft consumes 2.4 billion gallons of jet fuel per year. The A-10 test flight went well with “no problems whatsoever” according to the pilot.

[Motown_Johnny]

15. bio fuels do have a drawback

besides that this was a blend, and that the Warthog is one of the more fuel efficient fighters...


You can only produce about 100 gallons of Carmelina oil per acre.
http://www.ecogeek.org/component/content/article/2022

I don't know how much that oil weighs but I assume it is lighter than water, water weighs 8 lb. per. gallon so I will estimate it at 6 lb. per. gallon.


So you can get about 600 lb. of oil from one acre of land.



http://www.aerospaceweb.org/aircraft/attack/a10/

^snip^

Fuel Capacity internal: 10,700 lb (4,855 kg)

Range typical: 1,080 nm (2,000 km)


So you would need roughly 18 acres of land to produce one tank full (internal tanks only) of fuel for one plane IF it could run on pure Carmelina oil. This gets you about 1000 miles of flight.


Until there is a huge breakthrough in production using algae I don't consider this a viable alternative. Corn based ethanol is bad enough.

[neverforget]

16. I realize all that. I was just posting to show that the USAF is working on

alternates be they sustainable or not.

The USAF was also going to work on coal-to-liquid fuel like the Germans used in WW2.
http://www.msnbc.msn.com/id/23811258/

but apparently not anymore:
http://www.af.mil/news/story.asp?id=123133232

then again, maybe so:
http://www.technologyreview.com/energy/24405/

[Motown_Johnny]

18. ROFL.... I guess that is on a need to know basis

So basiclly....



They are spending tax payer money on a non-sustainable program, nice.



At least they are trying

[Motown_Johnny]

19. ROFL.... I guess that is on a need to know basis

So basiclly....



They are spending tax payer money on a non-sustainable program, nice.



At least they are trying

[Dr Morbius]

13. Maybe, and maybe not, but there are things we can do to "green"...

...up the airline business. Like applying a small tax on air freight, say a tenth of a penny a pound. This won't bother most businesses; it doesn't even come to $100 until one is shipping ten thousand pounds. But it will discourage companies from picking fruit in America and sending it to South America or Mexico to be sorted and polished. It will discourage companies from catching tuna off the New England coast and shipping it to the far east for canning, only to ship it back to America for consumption. This sort of thing happens all the time, and a very small tax on air freight will serve to disencourage this kind of business model. That's better for our economy; local businesses do a lot more good than merely employing people. It's also something that will cut down on the fossil fuels needed for planes.

I really believe that lots of planes are carrying cargo, not people; I don't know the percentages but I know it's significant.

[KG]

14. Steam

http://www.youtube.com/watch?v=qdgLtzWJhbU&feature=related

[bridgit]

20. Not sure they'd be any good for crop dusting but yeah - once you get them up there ~

http://www.solarimpulse.com

http://www.nasa.gov/centers/dryden/news/FactSheets/FS-034-DFRC.html

[KittyWampus]

26. that is beautiful.

[bananas]

23. Planes are very fuel-efficient - about 100mpg per passenger

They are developing even more fuel-efficient designs, as well as biofuels.

http://www.howstuffworks.com/question192.htm

How much fuel does an international plane use for a trip?

A plane like a Boeing 747 uses approximately 1 gallon of fuel (about 4 liters) every second. Over the course of a 10-hour flight, it might burn 36,000 gallons (150,000 liters). According to Boeing's Web site, the 747 burns approximately 5 gallons of fuel per mile (12 liters per kilometer).

This sounds like a tremendously poor miles-per-gallon rating! But consider that a 747 can carry as many as 568 people. Let's call it 500 people to take into account the fact that not all seats on most flights are occupied. A 747 is transporting 500 people 1 mile using 5 gallons of fuel. That means the plane is burning 0.01 gallons per person per mile. In other words, the plane is getting 100 miles per gallon per person! The typical car gets about 25 miles per gallon, so the 747 is much better than a car carrying one person, and compares favorably even if there are four people in the car. Not bad when you consider that the 747 is flying at 550 miles per hour (900 km/h)!

[scubadude]

24. No Problem. We invented nuclear ramjets way back in the 50's. nt

[Tesha]

29. Yeah, they didn't have any shielding and irradiated everything in their path...

...but considering that they were designed for one-way missions
to deliver nuclear weapons, the swath of destruction that they left
in their wake was considered a feature, not a bug.

Tesha

[scubadude]

30. Yeah, it is kinda funny how things work out....

[NNN0LHI]

25. Solid fuel rockets?

Be a hell of a ride.

Don

[anarch]

27. I sure hope so

or else it's so long to aviation, which I would regard as an awful shame.

I have high hopes for advances in renewable biofuels that would work much like petroleum, and/or eventual advances in physics that would allow for electro-gravitic propulsion or something else all science-fictiony.

Personally, I'd like to see some research with high-capacity, high speed (or at least higher speed than what we can do now) airships. Maybe if we could get one across the Atlantic in the timeframe of a day or two, that would be a relatively environmentally friendly alternative to our current options.

[krispos42]

32. Too much frontal area. to make it efficient

You're pushing a lot of air out of the way with a dirigable. Probably could simply use a propeller plane with nice straight wings to do the same thing in the same timeframe with better mileage.

Check it out:
http://www.democraticunderground.com/discuss/duboard.php?az=view_all&address=115x115137

[bridgit]

33. Negative Mass Propulsion

Context Physics excursus on negative mass propulsion

Description Negative matter is a hypothetical form of matter whose active-gravitational, passive gravitational, inertial, and rest masses are oppisite in sign to normal, positive matter. Negative matter is not antimatter (which has a positive mass). If an object made of negative matter could be obtained and coupled by elastic, gravitational, or electromagnetic forces to an object containing an equal amount of positive matter, the interaction between the two objects would result in an unlimited amount of unidirectional acceleration of the combination without the requirement for an energy source or reaction mass. This would not violate the Newtonian laws or General relativity.

http://www.itsf.org/resources/factsheet.php?fsID=79

[Tailormyst]

34. I think eventually they will be