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considering the important role of hydrocarbon in the world economy and everybody everyday life ,
a bit of a quick overview might not be remiss .
Hydrocarbons are ,surprise , surprise chemical compounds made of carbon and hydrogen
chemists are notorious for their descriptive precision since Lavoisier
the basic dynamic is that carbon has a valence of four while hydrogen has one , think of plugs
the first cab of the rank is methane one carbon and four hydrogen , hence its description of CH4
that's natural gas , there is plenty of it just ask Gazprom
next is using one of the plug to put another carbon and another hydrogen to fill the blank .. Ethane C2H5
rather more rare and usually mixed with methane
then on add more carbon and we get ....propane C3H6 , butane C4H7 , pentane C5H8 .......etc etc
the chemical properties they have in common is that they burn very very well
their physical properties is that one start with a gas , hard to liquefies ,
to stuff which might be liquid or gas at a drop of a hat , they are called "condensates" and the name is very much fifty shades of grey
the long hydrocarbons become liquid ....then gooey ....then like pitch ....then like road tar
the gas is great stuff , easy to pipe but pretty hard to transport by ship or train
the liquids are God's gift to the automotive industry
the gooeys are not so popular but can be used or cracked
ultimately the really hard stuff can be used ......as road tar ( you could have guessed it )
when the stuff is extracted from the ground it is virtually useless , except in some benign fields
it is quite common to have everything mixed , but usually one fraction is dominant
the deeper one go the more Methane there is an less of everything else
it has to be scrubbed some , dried some and all the complicated family sorted from each others
the refining is where the good stuff is packaged for retail ,
there is some use for the chemical industry , mostly light stuff like gas , condensates and a light liquid called naphta
the really big sellers are petrol in the Anglo world or called gasoline in the US , its a bit heavier than naphta
for making it the optimum compound is octane C8H18
if it was a boxing class it would be middleweight
always the best technique , fast and furious
the next in weight is the condensates , aviation fuel , diesel this kind of things ,they are the very best fuel
those condensates are the very crux of peak oil for me ,
in a boxing analogy they are the light heavyweight , the most punch for the fastest longest strike
there is at the bottom of the distillation columns some pretty heavy goo , sold as "heavies" or Bunker fuel
it's the bees knee for powering ships and furnaces , lot of heating power
as the heavyweights , they pack a massive heating punch but are not so good for moving around
refining not only use everything but even succeed in making more stuff per volume than came in ,called "refining gain"
residues are either cracked ,refined as carbon black (tyres) burned on site in the furnaces or sold as surfacing material
this is of course a ridiculously simplified view but if you know very little about hydrocarbons
it will allow you to pass to a knowledgeable person as some one which know very little about it