@pivoxa15
Andrew Mason said:
Not a very scientific approach. Since humans don't work as well when drinking gasoline does that mean that gasoline contains less energy than milk?
Is it that there is more energy in fossil fuel or is it that the energy is more accessible?
AM
Interesting question.
Since fossil fuels are simple Hydrocarbons they are all carbon backbones with Hydrogen atoms attached. For example, the simplest fossil fuel is Methane (C1H4), which is one Carbon surrounded by four Hydrogens. The next simplest is Ethane (C2H6), then Propane (C3H8), Butane, Pentance, Hexane, Heptane, Octance, etc...
To give you more perspective on the word Fossil Fuels, it includes all of these:
- Natural gas (C1-C4)
- Straight-run gasoline (C5-C11)
- Kerosene (C11-C14)
- Gas oil (C14-C25)
With this in mind, to answer your question, live plants have their Hydrocarbon content locked into complex molecules that they use for biological function, so that the hydrocarbons are not found isolated in any part of the plant. For example, a live plant may have compounds in it that have the basic hydrocarbon backbone structure to them, but they are also attached to atoms like Phosphorus, Nitrogen, Oxygen, etc. Whereas, dead plants which have been buried under heavy pressure for millions of years, have two factors that contribute to their liberation of their hydrocarbons; namely Decay, and Heat/Pressure. Both of these factors combined, over sufficient time, help to break the atomic bonds of a plant's hydrocarbon compounds and break off any undesirable residues like the atoms mentioned above, so that a purer, more combustable hydrocarbon emerges.
As a side note, the best fuels have high octane numbers (100 = best, 0 = worst). Octane number is determined prinipally by how 'branced' a hydrocarbon is. For example, Heptane (C7-H16) is a straight line of carbons that looks like this C-C-C-C-C-C-C and has an awful octane number of 0. While, 2,2,4-Tirmethylpentane (C8-H18) has three branches and has a perfect octane number of 100. For this reason, unbranched hydrocarbons are 'catalytically cracked' into smaller pieces and then recombined into larger branched hydrocarbons that are more useful as fuel.
Hope this helps.
