Non-fossil based fuels

[Martin]

Hi' date=' I'm a writer, not a science-type person. I'm hoping someone here can help me out. I'm working on a piece of fiction that takes place in a futuristic time when fossil fuels are not available (either by depletion, lack of access or perhaps cultural taboo; I've not determined).

 

My question is this: What other fuels, not based on petroleum, would be available to this society?[/quote']

 

As everybody seems to always be pointing out

the easiest fuel to make if you have electricity, is hydrogen

(by electrolysis of water)

 

But it is possible to react H2 with CO2 to produce methanol CH₃OH

 

and methane (natural gas) CH₄

 

 

Plants do all their chemistry by absorbing CO2 out of the air.

I think a civilization could also get its carbon this way, rather than mining coal or pumping oil from the ground.

 

In your SciFi story, what is the percentage CO2 in the air?

This would be an important fact to know about that world.

If the percentage CO2 is, say, one percent

then all the people need to do is develop a type of porous membrane that

concentrates CO2 from the air (lets O2 and N2 thru but blocks CO2)

then they can electrolyse water and get H2 and make all the usual hydrocarbon chemicals.

 

then they would be like plants are now.

they could do all carbon chemistry but never touch the taboo coal or

the taboo petroleum

and they would not be adding to the greenhouse burden

 

(this would be too expensive right now for our civilization I guess, but it is

chemically possible)

[YT2095]

H2O2 takes more chems and energy to produce, so much so that you may as well use that energy in the 1`st place and cut your losses

[5614]

H2O2 takes more chems and energy to produce, so much so that you may as well use that energy in the 1`st place and cut your losses

 

ok, fine!

 

[there goes those dreams]

 

you can do some cool experiments with hydrogen peroxide, it can be quite violent, when mixed with the right things! but then, so can everything...

 

is h2o2 a suitable fuel? is it reactive enough?

[budullewraagh]

actually, i personally dont think buckminsterfullerene can be too violent when mixed with anythingthing (at stp)

 

h2o2 is a good fuel but, as yt said, the energy required to produce it is greater than the energy one can obtain from it.

[Lance]

H2O2 is not a fuel... It’s an oxidizer. However, if you mix it with any of the liquid fuels mentioned above you will get a nice rocket fuel, Assuming it’s high purity.

[Martin]

 

h2o2 is a good fuel but' date=' as yt said, the energy required to produce it is greater than the energy one can obtain from it.[/quote']

 

I disagree with Lance, who says h2o2 can only serve as oxidizer

and I agree with Budul, who says it can be used as a fuel.

 

I believe if you have a tank of concetrated h2o2 you can use it to run a turbine----if you pump it over a catalyst it will turn to h2o steam and hot oxygen gas and ordinary water----it will expand a lot in volume and this can be used to drive a turbine. So it is a monofuel, one of those fuels that do not need another reagent.

 

But h2o2 has also been used as an oxident in driving German WWII torpedos IIRC. I think the system was to combine h2o2 at the point of combustion with alcohol-----in the right proportions this would make steam and carbon dioxide and could also drive a turbine.

 

this could have advantages over making the torpedos battery-powered electric motor type.

 

I dont know much about torpedos. I just saw this use of hydrogen peroxide mentioned in a magazine long ago.

[Logics88]

And hydroelectric. Steam wells/geysers. Heck, even heat from volcanoes! Radioactive decay. Burning of dead animals. That's all I can think of.

raqdioactivity, what the hell does that have to do with burning animals? radiioactivity would give them cancer!

[jdurg]

How do you think the earth got all of it's heat? The majority of the thermal energy of this planet is caused by the radioactive decay of Uranium, Thorium, and their daughter products.