53
votes
Accepted
Why isn't ethane used for cooking?
Probably the biggest drivers behind using methane as a fuel is that it is abundant in natural gas and is (currently) mostly useless as a chemical feedstock.
Ethane makes up a few percent of natural ...
- 12.9k
43
votes
Accepted
Why doesn't NASA or SpaceX use ozone as an oxidizer for rocket fuels?
As is usual with rocket fuels, the problems of ozone are practicality not performance
Almost every answer for why a specific rocket fuel component is used or not will end up referring to John D Clarke'...
- 35.5k
39
votes
Why isn't ethane used for cooking?
In both cases, there appears to be a confusion of terminology between common and technical uses.
We commonly use methane and propane for cooking (and home heating), but not ethane. I would expect ...
- 17.3k
19
votes
Accepted
Does all fire only emit light on its outermost shell?
The answer is NO.
The article you quote makes a completely unwarranted generalisation that "all flames are hollow". This is true of some flames but only because the fuel that is burning is ...
- 35.5k
18
votes
What single, pure compound would best replace petrol?
Higher $\mathrm{RON}$ seems possible. Yet the boiling point rises accordingly while heat of combustion remains roughly the same. Here are two compounds that fit all posed criteria.
\begin{array}{|c|c|...
- 7,021
17
votes
Accepted
Can a stoichiometric mixture of oxygen and methane exist as a liquid at standard pressure and some (low) temperature?
There's a NASA report that looks into this: "ON THE SOLUBILITIES AND RATES OF SOLUTION OF GASES IN LIQUID METHANE", Hibbard and Evans, 1968 and concludes that such mixtures are possible.
Starting on ...
- 544
17
votes
Accepted
Where does the energy in coal bonds come from?
Indeed it's in some way counterintuitive to say that the sun's energy is 'stored' in the coal bonds. Energy never comes from breaking bonds, it is released when forming bonds.
In the case at hand, the ...
- 717
15
votes
Why doesn't NASA or SpaceX use ozone as an oxidizer for rocket fuels?
Liquid ozone is rather stable (as in "can be stored") as an up to 70% solution in LOx, if you add some stabilisers. That would give quite a bit of additional boost in a rocket, but it's ...
- 12k
14
votes
Where does the energy in coal bonds come from?
As has been pointed out the energy comes in the form of visible light from the sun. The reaction written in summary or overview is
$$\displaystyle \ce{2H2O \overset{light}\to O2 + 4H^+ + 4e^-}$$
$$\...
- 30.1k
12
votes
What can I use as a fuel for an engine with carbon dioxide as the oxidizer?
Usually when we say something "burns", it's being oxidized. In the case of carbon dioxide only the oxygen can be oxidized, by displacing it as the element; that requires fluorine or a sufficiently ...
- 53.3k
12
votes
Can a stoichiometric mixture of oxygen and methane exist as a liquid at standard pressure and some (low) temperature?
To add to the Bob's excellent answer (and expand a bit on my comment there), I've found two other potentially interesting papers to peruse.
The first is R.J. Hodges and R.J. Burch, Cryogenics 7 112-...
- 8,349
10
votes
What chemical reactions could ancient people use to propel projectiles?
The answer depends on what do you mean for ancient people. There are a lot of reactions that could produce gas for ejecting projectiles. The most common was the mixture of sulphur, potassium nitrate $\...
- 9,069
9
votes
Accepted
Can ethanol alone be used as Fuel?
Ethanol clearly can be used as a fuel.
But there are several reasons why it isn't.
First is simple economics. Ethanol costs more to produce than gasoline: oversimplifying only slightly, ...
- 35.5k
9
votes
How is octane rating defined for negative values and those over 100?
I recommend the @Stanley Yu own answer, as I admit I was not particular familiar with the shape of the ON number curve.
It is done by an extrapolation of the critical compression ratios of mixtures 0-...
- 39.4k
9
votes
Accepted
Effect of coal and natural gas burning on particulate matter pollution
At the same energy outcome, natural gas produces less carbon dioxide than coal. In a way, natural gas is half way between coal and hydrogen.
Coal produces smelly smoke, solid particles, sulfur dioxide ...
- 39.4k
8
votes
Accepted
How can we produce gasoline from electricity without fossil fuels?
Historically, this sort of process has been done with the Fischer–Tropsch process.
The core of this process is to use "syngas" (a mixture of $\ce{CO}$ and $\ce{H2}$) in the presence of a catalyst to ...
- 4,855
8
votes
What is the carbon content, by weight, of vegetable oil?
Vegetable oils are mainly made of glycerol esters of oleic acid, linoleic acid and palmitic acid. For example, the fatty acids extracted from olive oil are a mixture of $74$% oleic acid, $11$% ...
- 27.1k
8
votes
Where does the energy in coal bonds come from?
Photosynthesis is a little like the reverse of burning
The idea that chemicals or their bonds store energy needs some clarification. The storage is always relative to some other reachable arrangement ...
- 35.5k
7
votes
Is it more economical to liquify natural gas to ship overseas or convert it to propane (C3H8) and ship it overseas?
Gas to liquid technology is known, but propane isn't a good choice of end product
The idea of converting natural gas (which is mostly methane) into liquids is widely used not least because the earth ...
- 35.5k
7
votes
How is it possible to safely use carbon monoxide as a fuel?
During WWII many cars were powered by a gasogene engine, which transformed wood or charcoal into a synthetic gas composed by $\ce{CO}$, $\ce{N2}$, $\ce{H2}$ and $\ce{CO2}$. Thus the use of $\ce{CO}$ (...
- 301
7
votes
Accepted
Is liquid hydrogen rocket propeller pollution free?
I'll address you questions in order:
1) Yes, that is basically the correct reaction, although not quite balanced; here is how I would write it:
$$\ce{2H2(l) + O2(l) -> 2H_2O(g)}$$
2) ...
- 17.4k
6
votes
Accepted
How is it possible to safely use carbon monoxide as a fuel?
Carbon monoxide has been used as a fuel but not usually by itself.
The reason why we don't use it much now is that there are better, safer alternatives.
Before the widespread use of natural gas as a ...
- 35.5k
6
votes
Accepted
Why are branched alkanes used as fuels instead of straight chain alkanes?
Because petrol engines work differently to diesel engines and the property differences matter more than the absolute energy of combustion
Your basic assumption is wrong: diesel engines use mainly ...
- 35.5k
6
votes
Flash point of naptha and propanol
Flash point relates to a open pan or pool of liquid with no wick.
The definition of flash point is the lowest temperture of a combustable liquid at which it will catch fire when a flame is presented ...
- 5,151
5
votes
What is the oxidation mechanism of gunpowder?
$\mathrm{KNO_3(s)}$ can oxidize charcoal without sulfur. It needs a "hot" primer through to get the reaction started. Sulfur's role is to lessen the ignition temperature.
See section in Wikipedia ...
- 22.2k
5
votes
What chemical reactions could ancient people use to propel projectiles?
One of the earliest use of Black Powder was crude large-bore handheld guns (early China). And, actually much more, to quote a source:
Other Song military applications of gunpowder included ...
- 5,468
5
votes
Why are branched alkanes used as fuels instead of straight chain alkanes?
The main reason for the high quantity of iso-octane is to prevent Engine Knocking. The Wikipedia page for Octane explains this quite well:
The octane rating was originally determined by mixing fuels ...
- 6,218
5
votes
Which is more efficient way to generate energy using hydrogen: direct hydrogen combustion or through fuel cell?
If you want energy as heat, the best way to generate energy is combustion. If you want energy as electricity, the best way is a fuel cell (which also produce some heat). If you want mechanical work, ...
- 27.1k
5
votes
Effect of coal and natural gas burning on particulate matter pollution
Dealing specifically with particulates would depend on the coal and burning conditions. You could look up a specific coal you are interested in; However generally it will contain a few % of each ...
- 3,719
4
votes
Accepted
Storage of methane in mineral oil or other liquid hydrocarbons
"Practical" can mean different things to different people, so I am not going to comment on that.
Instead I am going to address the question, of solubility of methane in hydrocarbons, without any ...
- 8,465
Only top scored, non community-wiki answers of a minimum length are eligible