aak777
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Fuel For Airliners When No More Fossil Fuel!?

Sun Mar 11, 2007 7:43 pm

So after a while when oil wells are dried out what will fuel the airplanes?
Is there any cheap and coast effective alternative fuel under research now days?
 
newagebird
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RE: Fuel For Airliners When No More Fossil Fuel!?

Sun Mar 11, 2007 8:11 pm

Theyre trying hydrogen fuel but there is a lot of logistical issues such as the great quantity required to achieve the same range aircraft have today. Don't worry about it, let the scientists come up with it, im sure they will as the world can't live without aviation.
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N231YE
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RE: Fuel For Airliners When No More Fossil Fuel!?

Sun Mar 11, 2007 10:14 pm

In the United States, there is a college that designed a way to derive bio-Jet fuel from soybeans. The problem was, is that the United States uses more Jet fuel than every farm in the USA could produce.

As for smaller, piston engined aircraft, there is aviation-grade ethanol in the works, but I don't know much on it.
 
levg79
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RE: Fuel For Airliners When No More Fossil Fuel!?

Sun Mar 11, 2007 10:24 pm

There was an article in the Airways a few months back talking about this problem. It made the problem sound so bad that you would get an impression that a few years down the road there would not be such a thing as the aviation. If I remember correctly, the quote used in the article was "the world would once again become large."

But as everyone else here, I hope that this problem will get resolved before it becomes a problem.

Leo.
A mile of runway takes you to the world. A mile of highway takes you a mile.
 
ba97
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RE: Fuel For Airliners When No More Fossil Fuel!?

Sun Mar 11, 2007 10:34 pm

There is a lot of time to work on this one. There is not much fuel out there at less than $40/bbl. More oil at $60/bbl and lots of oil at $100/bbl. When you start into the $150/bbl range, lots of options open. A very good example are the oil sands. Oil shales and extraction from some tricky places kick into gear the higher you go. The higher the price of oil, the more viable alternative energies become and the more competitive they are in the market. The alternate energy source price and what people are willing to pay to go from a to b will kick start the alternatives into real research and application. The issue with planes is that you need global adoption. A car is "local" transportation and having alternative energy for that engine is rather straightforward town/city/country specific. Having airports all over the world adopt fueling alternatives and the turn over of vehicles (the average car changes from its first owner after 5-7 years for example- a plane?--15 years?) makes all this much more tricky in action compared to the theory.

First you convert the cars, boats, trains, home heating, which will free up the refining into more sensitive uses like planes. I would say you have another good 20 plus years before alternatives on planes make any appearance. But then, I could be off my rocker.
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LAXintl
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RE: Fuel For Airliners When No More Fossil Fuel!?

Sun Mar 11, 2007 11:54 pm

With the US sitting on the worlds largest deposits of coal, there has been renewed interest into the use of coal based fuels. The technology has been around since pre WW2 with Germany having made successful mass use of such fuels. In addition there has been a strong push for hydrogen based synthetic fuels blends particularly by the USAF.

The US Dept of Defence along with private companies are actively involved in the research and trial of such fuels. Matter of fact a USAF B-52 was flown at the end of last year with such a fuel blend. Also David Neeleman of Jetbue has personally gotten involved in such research and is sponsoring legislation that would help make such fuels realistic.

Stories on USAF B-52
http://www.af.mil/news/story.asp?storyID=123026906
http://www.af.mil/news/story.asp?id=123035568

Jetblue / David Neeleman presentation
http://www.glennbeck.com/2006ads/jbluctl.pdf
From the desert to the sea, to all of Southern California
 
OPNLguy
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RE: Fuel For Airliners When No More Fossil Fuel!?

Mon Mar 12, 2007 3:00 am

Quoting Levg79 (Reply 3):
It made the problem sound so bad that you would get an impression that a few years down the road there would not be such a thing as the aviation.

At Hayden, Colorado (HDN), that's exactly what's going on now--they're out of Jet-A, and awaiting a delivery truck. Lots of folks flying in for spring break skiing causing high demand, but a refinery fire in Texas in mid-February has the normal distribution process all fouled up...
ALL views, opinions expressed are mine ONLY and are NOT representative of those shared by Southwest Airlines Co.
 
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Starlionblue
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RE: Fuel For Airliners When No More Fossil Fuel!?

Mon Mar 12, 2007 3:02 am

Quoting Ba97 (Reply 4):
There is a lot of time to work on this one. There is not much fuel out there at less than $40/bbl. More oil at $60/bbl and lots of oil at $100/bbl. When you start into the $150/bbl range, lots of options open.

Ba97 hits the nail on the head. When current fuels become more and more costly, investments in other fuels will start looking very reasonable.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
ma2mw
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Mar 13, 2007 5:16 am

There's no reason a jet engine couldn't run on ethanol if it was first set up to do so. What reply 3 might not be aware that the newest research is to turn the cellulose or the whole plant into ethanol as opposed to just the bean or kernel. They are developing special enzymes that will bread down the plant matter into ethanol. With this approach, I think the farmers could do the job (especially with more farmers). This is what Pres. Bush was talking about with switchgrass.
 
rwessel
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Mar 13, 2007 3:02 pm

Quoting Ma2mw (Reply 8):
There's no reason a jet engine couldn't run on ethanol if it was first set up to do so.

While running a turbine on ethanol would be no problem (with a few small modifications), ethanol has about 41% lower energy content than Jet-A per unit volume, although since it's about 7% less dense, it's only about 37% lower in energy content on a per unit mass basis. That’s not too big a deal on a ground vehicle carrying only a modest amount of fuel, but it would probably be way too big a hit for most aircraft.

Biodiesel is much closer to Jet-A energy densities (about 92% on a volume basis, 88% on a mass basis), although it's of *very* variable quality at the moment.

But in any event, there are all sorts of ways to make something like Jet-A if you’re willing to pay for it.
 
saintsman
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Mar 13, 2007 3:49 pm

The most obvious source of fuel is water. Hydrogen and oxygen. Once a cheap method of separating the two elements is invented the answer to the fuel crisis is there for all (except the Arabs as they haven't got any!). Non poluting too.

However, would big business stand for this? If you can get your fuel for free they are not going to make huge profits so it wouldn't surprise me to see the technology suppressed.
 
rwessel
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Mar 13, 2007 4:26 pm

Quoting Saintsman (Reply 10):
The most obvious source of fuel is water. Hydrogen and oxygen. Once a cheap method of separating the two elements is invented the answer to the fuel crisis is there for all (except the Arabs as they haven't got any!). Non poluting too.

Unfortunately you need to put as much energy into cracking H2O as you can get out of it by reacting the hydrogen and oxygen back to water. That might be an application for solar powered cracking stations (the sulfur-iodine cycle looks somewhat promising), since the hydrogen is basically a good energy storage mechanism.

At the very (and seriously unrealistic) best, you could collect a joule of solar (or any other) energy, crack some water, transport the hydrogen to some end user, and get back a joule. But it cannot be any less expensive than the original energy source.

If you want hydrogen, it's actually much less expensive to crack methane (natural gas) at the moment.
 
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Starlionblue
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Mar 13, 2007 7:36 pm

Quoting Saintsman (Reply 10):
The most obvious source of fuel is water. Hydrogen and oxygen. Once a cheap method of separating the two elements is invented the answer to the fuel crisis is there for all (except the Arabs as they haven't got any!)

"The Arabs as the haven't got any"? Your statement is a bit generalized. You seem to assume all Arabs live in the desert. Let's for a moment assume you mean Saudi Arabia. In that case there is plenty of water in the Red Sea for example.

Quite frankly I think you are suffering from the misconception that all oil producing countries in the Middle East are deserts populated by Arabs.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
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SEPilot
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Mar 13, 2007 8:21 pm

Quoting N231YE (Reply 2):
As for smaller, piston engined aircraft, there is aviation-grade ethanol in the works, but I don't know much on it.

Ethanol is totally unacceptable for all existing piston engine planes; all of them have components in the fuel system that ethanol attacks. Since the average age of a single engine plane is over 30 years, any new avgas replacement must not contain ethanol. The costs to convert all the planes out there to tolerate ethanol would be prohibitive.
There are many ways of making synthetic petroleum, and any organic matter is a potential source. I have read of one where they are converting garbage to oil, and are on the verge of making it commercially viable. The greatest potential source of fossil fuels in the world is actually the oil shale deposits in the Rockies, dwarfing the Middle East oil fields. Sooner or later someone will come up with an economically viable way to extract it.
The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
 
baroque
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Mar 13, 2007 9:16 pm

Quoting Starlionblue (Reply 12):
Quite frankly I think you are suffering from the misconception that all oil producing countries in the Middle East are deserts populated by Arabs.

This is a well established factoid.  sarcastic  And that entropy has yet to be invented is one of the most important corollaries of this factoid.
 
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Starlionblue
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Mar 13, 2007 9:27 pm

Quoting Baroque (Reply 14):
This is a well established factoid.

Lol. Just like all Iranians and Afghans are Arabs then? Sigh...
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
mrocktor
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Mar 13, 2007 10:02 pm

There is plenty of oil on the planet to fuel planes for centuries. Before oil runs out we will have workable fusion - unless the enviro-crazies manage to destroy our industrial society, that is.
 
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Starlionblue
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Mar 13, 2007 10:08 pm

Quoting Mrocktor (Reply 16):
There is plenty of oil on the planet to fuel planes for centuries. Before oil runs out we will have workable fusion - unless the enviro-crazies manage to destroy our industrial society, that is.

Have you been reading "Fallen Angels" by Flynn & Pournelle & Niven?  Wink In that book, the "enviro-crazies" have taken over the asylum and the lack of heating from industrial society has plunged the Earth into a new ice age.

Before you flame me, note that this was a work of FICTION.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
mrocktor
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Mar 13, 2007 10:31 pm

Quoting Starlionblue (Reply 17):
Have you been reading "Fallen Angels"

Never heard of it. I'm reading newspapers...
 
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Starlionblue
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Mar 13, 2007 10:51 pm

Quoting Mrocktor (Reply 18):
Quoting Starlionblue (Reply 17):
Have you been reading "Fallen Angels"

Never heard of it. I'm reading newspapers...

I know. I was making a joke. The book isn't really that good either.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
InnocuousFox
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RE: Fuel For Airliners When No More Fossil Fuel!?

Wed Mar 14, 2007 12:08 pm

I can't believe that we are having this discussion.  Yeah sure
Dave Mark - Intrinsic Algorithm - Reducing the world to mathematical equations!
 
baroque
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RE: Fuel For Airliners When No More Fossil Fuel!?

Wed Mar 14, 2007 2:14 pm

Quoting Starlionblue (Reply 15):
Lol. Just like all Iranians and Afghans are Arabs then? Sigh...

Of course, and while we are teaching them to be good Arabs, we can (part time) work on controlled heat transfer problems from fusion reactors running at 2 million C and then some. Actually, the heat transfer problem might be the easier one.  Wow!
 
thegeek
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RE: Fuel For Airliners When No More Fossil Fuel!?

Sun Feb 10, 2008 1:41 am

I personally think that by far, the most practical alternate fuel for airliners is LNG (i.e. liquid methane) in super insulated tanks. It actually contains about 15% more energy per unit weight (~50MJ/kg vs ~43MJ/kg) so on a long haul plane would likely result in weight and therefore fuel efficiency saving. Would result in a few challenges for refueling the cryogenic liquid, but nothing impossible, and with Jet Fuel getting more and more expensive, it is likely to pay eventually.
 
Jawed
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RE: Fuel For Airliners When No More Fossil Fuel!?

Sun Feb 10, 2008 3:44 am

We'll just go back to sail ships. Getting your FedEx package might take 6 months instead of 24 hours, but it will still arrive, eventually.
 
a380us
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RE: Fuel For Airliners When No More Fossil Fuel!?

Sun Feb 10, 2008 4:21 am

If they were to use water would that mean we would have more rain and snow?
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Sasha
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RE: Fuel For Airliners When No More Fossil Fuel!?

Sun Feb 10, 2008 8:13 am

Scientists could have come up with the solution of an alternative power source ages ago, maybe they already have... but all their efforts are being hampered and what is more - probably even sabbotaged and otherwise barred by the oil tycoons. This could probably once and for all free us of the need to use oil and this is what would make those few mega rich guys burst (as if they hadnt saved up enough already).

Nuclear energy might be eventually put to more widespread use, becoming conventional by the time it gets into aviation. Hydrogen, coal and cooking (sunflower) oil options would require larger tanks, larges planes (read: more of those composite material, metal...) and even more power would be required from the engines to drive these gigantic structures through air.
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ThirtyEcho
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RE: Fuel For Airliners When No More Fossil Fuel!?

Sun Feb 10, 2008 10:07 am

Out of oil?

You won't be flying anywhere or driving, either.

Mostly, you'll be standing guard with a shotgun all night, ready to shoot any of your neighbors who try to steal the potatoes you have growing in your back yard. You will have nothing to eat but these potatoes, you see.

And you burned all of your furniture in the fireplace just to keep warm this past winter.

Your trees are all gone as they were cut down for fuel by the millions of homeless people who fled the freezing and starving cities. These people now wander the roads, on foot, as a lawless band which is bent on robbery, rape and murder just to survive. They are all headed south in a virtual plague of locusts that devours everything.

Airplanes? They have been stripped of anything useful and people have taken them over for shelter. Talk about fighting for a seat.
 
baroque
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RE: Fuel For Airliners When No More Fossil Fuel!?

Sun Feb 10, 2008 11:37 am



Quoting SashA (Reply 25):
Scientists could have come up with the solution of an alternative power source ages ago, maybe they already have... but all their efforts are being hampered and what is more - probably even sabbotaged and otherwise barred by the oil tycoons. This could probably once and for all free us of the need to use oil and this is what would make those few mega rich guys burst (as if they hadnt saved up enough already).

Don't worry about the oil tycoons, you would be better off fretting at the physical-chemists who thought up the concept of entropy. That is going to be a far more difficult hurdle to overcome.

Crude oil to fuel for cars and planes - not much chemical work to do, low increase in entropy of the system.

Nothing to do with tycoons or strange business practice, just simple physical chemistry.

Coal to fuel for cars and planes - plenty of well understood chemical work, varst increase in entropy of the system, hence low thermal efficiency. Equals high cost.
 
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SEPilot
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RE: Fuel For Airliners When No More Fossil Fuel!?

Sun Feb 10, 2008 7:30 pm

The latest info that I have been seeing is the theory that fossil fuels aren't fossil fuels at all; that they are the product of geological processes and are being continuously generated. If this is true then they are essentially inexhaustible and are being continuously renewed. I can remember my earliest memories of any discussion of oil supplies being when I was about six years old, and my parents and others saying that we had about a 50 year supply of oil. I had a neighbor a while ago who was a generation older, and he recalls discussion in the 30's being that we had about a 50 year supply of oil. During the first oil crisis in the 70's the talk was always that we have about a 50 year supply of oil. Now, 50 years after my first memory of the topic the consensus seems to be that we have about a 50 year supply of oil. My prediction is that we will always have about a 50 year supply of oil.
The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
 
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Starlionblue
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RE: Fuel For Airliners When No More Fossil Fuel!?

Sun Feb 10, 2008 11:25 pm



Quoting SEPilot (Reply 28):
I can remember my earliest memories of any discussion of oil supplies being when I was about six years old, and my parents and others saying that we had about a 50 year supply of oil. I had a neighbor a while ago who was a generation older, and he recalls discussion in the 30's being that we had about a 50 year supply of oil. During the first oil crisis in the 70's the talk was always that we have about a 50 year supply of oil. Now, 50 years after my first memory of the topic the consensus seems to be that we have about a 50 year supply of oil. My prediction is that we will always have about a 50 year supply of oil.

So true. The doomsayers are always around.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
thegeek
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RE: Fuel For Airliners When No More Fossil Fuel!?

Mon Feb 11, 2008 12:09 am



Quoting Starlionblue (Reply 29):
Quoting SEPilot (Reply 28):
... My prediction is that we will always have about a 50 year supply of oil.

So true. The doomsayers are always around.

Even so, isn't the world having significant trouble finding new large fields, combined with rapidly increasing demand in China and India? I think we're looking at $150/barrel or more oil within a decade, which will be enough to cause some alternatives to be economically viable for land transport.
 
N231YE
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RE: Fuel For Airliners When No More Fossil Fuel!?

Mon Feb 11, 2008 12:40 am



Quoting SEPilot (Reply 28):



Quoting Thegeek (Reply 30):

True. I venture to say that oil will always be around, its more of cheap oil that is in question.
 
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Starlionblue
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RE: Fuel For Airliners When No More Fossil Fuel!?

Mon Feb 11, 2008 1:57 am



Quoting Thegeek (Reply 30):

Even so, isn't the world having significant trouble finding new large fields, combined with rapidly increasing demand in China and India? I think we're looking at $150/barrel or more oil within a decade, which will be enough to cause some alternatives to be economically viable for land transport.

I'm going to chime in with the following statement from N231YE.

Quoting N231YE (Reply 31):
True. I venture to say that oil will always be around, its more of cheap oil that is in question.



Quoting SashA (Reply 25):
Scientists could have come up with the solution of an alternative power source ages ago, maybe they already have... but all their efforts are being hampered and what is more - probably even sabbotaged and otherwise barred by the oil tycoons. This could probably once and for all free us of the need to use oil and this is what would make those few mega rich guys burst (as if they hadnt saved up enough already).

Break out the tinfoil hats! Seriously. If there was an economically viable alternative, we would be using it. If oil keeps increasing in price, this will have three effects:
- Known oil fields previously deemed too expensive to exploit will be opened.
- Exploration in places previously deemed too expensive will occur, and oil will be found in some of those places.
- Development and implementation of alternative energy sources will occur.
"There are no stupid questions, but there are a lot of inquisitive idiots." - John Ringo
 
N231YE
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RE: Fuel For Airliners When No More Fossil Fuel!?

Mon Feb 11, 2008 4:55 pm

Quoting Starlionblue (Reply 32):
Break out the tinfoil hats! Seriously. If there was an economically viable alternative, we would be using it. If oil keeps increasing in price, this will have three effects:- Known oil fields previously deemed too expensive to exploit will be opened.- Exploration in places previously deemed too expensive will occur, and oil will be found in some of those places.- Development and implementation of alternative energy sources will occur.

Still, expensive oil=more alternatives open. There are huge deposits of oil sand and oil shales in Canada and the Arctic, and of course, the USA with its massive coal deposits could sustain itself on coal-to-oil technologies. The only problem is, that right now, they are too cost prohibitive to use. But if oil prices rise, then they will become a viable alternative.

Again, these alternatives rely on rising oil prices to become an economic alternative. These alternatives are expensive themselves, so one should be able to see the connection of more costly oil to pay for more costly alternatives or vice-versa.

Thus why I said cheap, oil-that is easily refined stuff that doesn't require cooking rocks, chemically reformulating stuff, etc.

[Edited 2008-02-11 09:12:14]
 
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SEPilot
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RE: Fuel For Airliners When No More Fossil Fuel!?

Mon Feb 11, 2008 5:14 pm



Quoting Thegeek (Reply 30):
Even so, isn't the world having significant trouble finding new large fields, combined with rapidly increasing demand in China and India?

As technology improves more and more oil becomes economically recoverable; it seems that every week or so I hear about some new find. Also, if what I posted earlier about oil being from geological instead of fossil processes, then there are far more places where oil could be found. Presently, exploration takes place in places where the scientists predict that it is likely based on the theory of fossil formation; if in fact it is geologically formed there are many, many places it could be where nobody has thought to look.
The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
 
cloudy
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Feb 12, 2008 12:03 am

Some methods of getting oil that are expensive now - like extracting it from tar sands, etc. - will get less expensive later due to new technologies and economies of scale. That has already happened with oil extracted from deep underneath the seafloor. On the demand side, a lot depends on just what sort of societies China and India turn into as they get richer. What they do matters more than what the US and Europe do, because of their economic growth and huge population.

Aircraft will be the last vehicles to stop using "fossil" fuels, because energy density is more important to aircraft then to surface vehicles. This goes for both the amount of energy per unit volume and per unit of weight.

A lot of what aircraft carry does not need aircraft speed. Some stuff needs to be shipped faster than a container ship can take it, but doesn't need to be there the next day. We probably will see a revival of alternatives that offer a compromise between the efficiency of the sea and the speed of the air. Airships, ground effect craft such as Boeing's "Pelican", and faster versions of modern ships come to mind.


On the various alternatives..,

Hydrogen has better energy density than kerosene per unit of weight, but much less per unit of volume. The main difficulty is in storing it cheaply and safely. Once people get over their irrational fear of nuclear power and its waste products, making the electricity to produce hydrogen should not be a major problem. More politically correct energy sources can also be used to make the stuff, too.

Others have touched on biofuels such as ethanol and biodiesel. One thing to remember with these is that farmland is itself a limited resource. It may be preferable to look elsewhere then to drive up the price of food, and convert more and more natural lands to agricultural use.

There is no known way of storing electricity that could economically power an aircraft, because of low energy density. Also, batteries, etc. do not loose weight during flight like an aircraft's fuel load does. It may be possible, however, to beam energy to an aircraft. The heavy part of an electric power system is the mechanism used to store electricity. The electric motors, etc. are relatively light. Beamed power could be used at takeoff, to start. This would allow a plane's airframe and conventional engines of a plane to be almost completely optimized for cruise - resulting in a large savings. Also, most of the fuel load needed to carry the plane to altitude would be saved. That is a substantial savings on a long haul flight. Eventually, most of the power for a flight could come from a microwave beam relayed from space. The aircraft would need carry only enough on board energy to take it to an alternate airport in an emergency. A plane using beamed energy could be a lot lighter then modern long-haul aircraft - since a great deal of, say, a 777-200LR's structural weight is only necessary because of its heavy fuel load. This would be for the far future, but I can see it happening if kerosene becomes expensive enough.
 
rwessel
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Feb 12, 2008 6:33 am



Quoting Thegeek (Reply 22):
I personally think that by far, the most practical alternate fuel for airliners is LNG (i.e. liquid methane) in super insulated tanks. It actually contains about 15% more energy per unit weight (~50MJ/kg vs ~43MJ/kg) so on a long haul plane would likely result in weight and therefore fuel efficiency saving.

For aircraft, the big problem with LNG is volumetric energy density. At best it's about two-thirds that of Jet-A, which means that you'd need to increase the size of the tanks by 50%. That plus the added insulation and structure for the quite high pressures involved, make LNG a less than ideal solution.

People keep forgetting how truly remarkable the medium chain hydrocarbons are in terms of ease of handling, and energy density (in both mass and volume terms). Aviation will likely be one of the last users of medium chain hydrocarbons, for just those reasons. And if you had ample methane supplies, but no oil, you can convert that to short/medium chain liquid hydrocarbons without too much difficulty (the Fischer-Tropsch process has been in the news recently for that purpose). Other bigger users, like cars, are much better candidates for alternative fuels with less favorable energy densities (in either or both mass or volume terms).
 
cobra27
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Feb 12, 2008 7:53 am

Coal powered engines. Each engine will have its own coalmen to dig coal
 
thegeek
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Feb 12, 2008 8:55 am



Quoting Rwessel (Reply 36):
Other bigger users, like cars, are much better candidates for alternative fuels with less favorable energy densities (in either or both mass or volume terms).

You, and every one else who has said this is probably right. But I would add that the first thing which should be taken off oil dependence is probably locomotives. Centralised refuelling and virtually irrelevant energy density together with large scale high fuel use swings me to these conclusions. Perhaps cars use more of the world's oil, but they're less easy to change over.
 
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SEPilot
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Feb 12, 2008 11:03 am



Quoting Thegeek (Reply 38):
But I would add that the first thing which should be taken off oil dependence is probably locomotives.

Locomotives are the best candidates for electrification (as has already happened in much of Europe) as the cost of adding wiring to the tracks is relatively minor. Other posters have brought up nuclear power; I agree that it is vastly underutilized, mostly because of politics. Even if it does turn out that oil is a fossil fuel instead of geologically formed I believe that the future is synthetic oil rather than any new form of energy storage; synthetic oil can be made from coal, from garbage, and from natural gas, and seems to be the most suitable fuel for most transportation applications. I do not think hydrogen will ever be practical as a fuel; it is too dangerous and too difficult to store and transport. Since hydrogen molecules are the smallest molecules that exist hydrogen will leak where no other gas will. And since hydrogen doesn't liquefy until very close to absolute zero liquid hydrogen is not practical. But in fact the most abundant known source of petroleum on earth is the oil shale in the western US; sooner or later someone will come up with an economical process to recover it.
The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
 
xv408
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Feb 12, 2008 11:34 am

Some posters have suggested that big business is squashing any attempt to develop alternative fuels. Others have pointed out that biofuels need large areass of land otherwise needed for food, and clearance of rainforest generates huge ammouts of carbon dioxide.
This article is interesting in that context. Shell, the petroleum giant, is funding a research project to use algae to create diesel.
http://www.independent.co.uk/news/bu...esearch-site-in-hawaii-764606.html
Interesting reading.
 
tdscanuck
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Feb 12, 2008 4:54 pm



Quoting SEPilot (Reply 39):
I do not think hydrogen will ever be practical as a fuel; it is too dangerous and too difficult to store and transport.

It's difficult to store and transport, but why dangerous? Gasoline is far worse.

Tom.
 
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SEPilot
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Feb 12, 2008 7:20 pm



Quoting Tdscanuck (Reply 41):

It's difficult to store and transport, but why dangerous? Gasoline is far worse.

Gasoline vapors will only ignite at certain concentrations; I believe hydrogen will ignite much more readily and with a much wider range of concentrations.
The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
 
bond007
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Feb 12, 2008 7:36 pm



Quoting Aak777 (Thread starter):
So after a while when oil wells are dried out what will fuel the airplanes?

Well, we should really be honest here and say we have no clue.

We are talking so far into the future, I guarantee we won't be using conventional turbines or conventional aircraft ... we can only guess what will power the aircraft of the future... none of us really have any idea!

We only invented the gasoline internal combustion engine in the past 150 years, and the jet engine in the past 70 years ... We couldn't even fly 100 years ago .... and since technology does not increase in a linear fashion, we are in for a suprize if we live another 100 years.


Jimbo
I'd rather be on the ground wishing I was in the air, than in the air wishing I was on the ground!
 
rwessel
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RE: Fuel For Airliners When No More Fossil Fuel!?

Tue Feb 12, 2008 10:36 pm



Quoting SEPilot (Reply 42):
Gasoline vapors will only ignite at certain concentrations; I believe hydrogen will ignite much more readily and with a much wider range of concentrations.

While that's true (H2 will ignite at concentrations of 13-59% in ordinary air, while most of the hydrocarbon vapors are limited to about 6-14%), and it will ignite from a smaller spark (although that's not significant given that the energy needed to ignite hydrocarbon vapors is basically miniscule to start with). OTOH, it's almost impossible to achieve the required concentration of H2 in an open space, since it mixes with air so rapidly, unlike hydrocarbon vapors which are quite heavy and pool well. On the flip side, there's a similar level of hazard in enclosed spaces.

H2 also will not self ignite as readily as most hydrocarbons (H2 won't ignite until about 550C, where as gasoline vapors will go in the mid-200s).

In short, the hazards are somewhat different in nature and quality, but we're not talking a big change from hydrocarbons. There are situations where H2 is clearly less hazardous, and situations where it's more hazardous. Overall I'd rate its net hazard as somewhere between gasoline and diesel-type fuels (including kerosene and Jet-A).
 
thegeek
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RE: Fuel For Airliners When No More Fossil Fuel!?

Wed Feb 13, 2008 12:23 am



Quoting SEPilot (Reply 39):
Locomotives are the best candidates for electrification

At the risk of going further off the topic, it is worth noting that in Oz there are diesel locomotives operating routes completely under wires. In Queensland this occurs mostly due to a shortage of electric locomotives, and in NSW, due to extortionate charges for electricity.

Technically, you are correct, but there doesn't seem to be much interest from the rail operators in electrification for freight in the US, and less in Oz.
 
baroque
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RE: Fuel For Airliners When No More Fossil Fuel!?

Fri Feb 15, 2008 2:39 pm



Quoting Thegeek (Reply 30):
Even so, isn't the world having significant trouble finding new large fields, combined with rapidly increasing demand in China and India? I think we're looking at $150/barrel or more oil within a decade, which will be enough to cause some alternatives to be economically viable for land transport.



Quoting N231YE (Reply 33):
Again, these alternatives rely on rising oil prices to become an economic alternative. These alternatives are expensive themselves, so one should be able to see the connection of more costly oil to pay for more costly alternatives or vice-versa.

Thus why I said cheap, oil-that is easily refined stuff that doesn't require cooking rocks, chemically reformulating stuff, etc.

Both good points, and there is no doubt that higher oil prices do make alternatives more attractive. However, beware the great con trick in citing a dollar price at which process X becomes economic. What actually happens is that all the known costs climb with the price of oil, and then just to make life difficult a few new costs pop up to ruin the day. Some alternatives will prove attractive as tar sands have already, but beyond that, it is difficult to predict which and at what price.

Quoting SEPilot (Reply 34):
Presently, exploration takes place in places where the scientists predict that it is likely based on the theory of fossil formation; if in fact it is geologically formed there are many, many places it could be where nobody has thought to look.

OK, well this is so well known, you had better tell us ignorami where to drill.

The sedimentary basins certainly have the most extensive deep drilling. Presumably you are suggesting that the older metamorphosed cratons around the basin margins are where to look??? Well they happen to be prospective for minerals and huge numbers of mineral holes have been drilled. None of the mineral holes in metamorphics has ever struck oil, although curiously a few in sedimentary basins have had oil returns.

So let me know where has not been drilled? I am really curious to extend my experience to find this mantle derived oil.
 
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RE: Fuel For Airliners When No More Fossil Fuel!?

Fri Feb 15, 2008 3:54 pm



Quoting Baroque (Reply 46):

So let me know where has not been drilled? I am really curious to extend my experience to find this mantle derived oil.

I do not know much about it myself, other than what I read. But my understanding is that if the theory I cited is correct, there could be oil just about anywhere, but it would be deeper than where it is currently found.
The problem with making things foolproof is that fools are so doggone ingenious...Dan Keebler
 
baroque
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RE: Fuel For Airliners When No More Fossil Fuel!?

Fri Feb 15, 2008 4:11 pm



Quoting SEPilot (Reply 47):
Quoting Baroque (Reply 46):

So let me know where has not been drilled? I am really curious to extend my experience to find this mantle derived oil.

I do not know much about it myself, other than what I read. But my understanding is that if the theory I cited is correct, there could be oil just about anywhere, but it would be deeper than where it is currently found.

So deeper than the 30,000 feet of wells such as Knotty Head in the GoM.

To cut a long argument short, while small amounts of methane are found in volcanics and in some deep metamorphic terrains, they are not similar in isotopic terms to the methane associated with oils and coal.

If you drill to say 15 kms, the average temperature at that depth is going to be about 15 +(28*15) Celsius = 435 C. We know that oils become unstable at temperatures of about 150 C. Any oil at that depth, would break down to methane and a petroleum coke, and possibly over 435 C some hydrogen would be generated.

If there were oil down there, where would it be and how would you get it to flow to the well? Porosities are extremely low - probably less than 0.5%. Conventional oilfields start to become difficult to produce once porosity gets below about 5%.

Aside from oil just not being in the deep crust or mantle (see the data on Siljan Ring drilling - Castano, J) it would be an impossible task to produce it if it were there.

The chemistry and physics of mantle derived oil have been discussed at great length. Basically, the chances of deep mantle oil are less than those of someone inventing a perpetual motion machine.

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