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What's So Special About Fossil Fuels?

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mejane

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Coal and oil are, of course, primary energy sources. But, the petrochemical industry goes far beyond this.

Am I right in thinking that all modern plastics are derived from fossil fuels? If so, why? What is so special about them? Why can't these long-chain polymers be derived from, say, sesame seed oil?

Help, please.

Jane.
 
My uninformed guess is that it would be easier (read: more convinient) to drag the stuff out of the ground, than arse about farming oils.

We'll have to consider something different soon though, it won't last forever.
 
Quantity for starters.

Pressed oils aren't normally sold by the barrel.
 
The future lies in crap; vast quantities of methane produced from the stuff could be tampered with and used to carry on at least a limited plastics industry after the oil dries up. Of course,if we stop burning all our oil and run engines on something else, we could have plastics for thousands of years.

*Edit: having just seen the above post, the future does indeed seem to lie in crap.*
 
that would be good.."long trip in the car tommorow dear... i'll have double curry tonight"
 
mejane said:
Coal and oil are, of course, primary energy sources. But, the petrochemical industry goes far beyond this.

Am I right in thinking that all modern plastics are derived from fossil fuels? If so, why? What is so special about them? Why can't these long-chain polymers be derived from, say, sesame seed oil?

Help, please.

Jane.
Click to expand...

Er. Ain't it to do with powerful oil multinationals? A vested interest in controlling as much production and market share of as many industries as possible?
It's just a question of greed and power.


If anyone tries to start a scheme to run cars on cheap veg oil, it get's scuppered by customs and excise or the fuel giants...
I'm sure the diesel engine was originally designed to run on plant oils!
There are countless conspiracy theories about it!


(I'd rather run my car on crap!):)
 
You cynical lot!

I was wondering whether fossil fuels are chemically better suited to producing long-chain polymers. Is it really just all about power and money? Why don't Exxon and their ilk spend a vanishing small percentage of their profits on researching alternatives?

Jane.
 
Oil is made up of thousands of different types of compounds, the vast majority of which are useful, so the products made from oil are many and varied, from different types of fuel, to different types of plastic.
Economics is the biggest factor, as oil is an extremely abundant resource that we're getting better at exploiting. There are vast reservoirs of the stuff.
The building blocks of the most common plastics are not present in vegetable oils. The most common plastic, polythene, is made up of polymerised gas molecules.

Exxon and co. are already researching alternatives in order to stay ahead of the curve, and have dedicated R&D departments. But until it becomes economically viable, it'll remain marginalised.

Hope this helps. I can provide more detail if you need it. :)
 
the long chain polimers in fossil fuels take milloins of years at high pressures. presures so high that it would be financially unviable to recreate in a production line, not to mention the fact we don't have a few million years to spare.

the reason why you cant use sesamie seed oil or rape seed oil is because the polimers (long chain molicules) just aren't long enougth, the ones you use to make plastics are extreamly long, and can oly be found in crude oil
 
I'm going to respectfully disagree there, Flash. Polymerisation is carried out in industrial processes and are not formed within the oil. The simpler building blocks, the monomers, are. You may be getting confused with the formation of diamonds which require ultra high pressures and temperatures to form. ;)
 
Dark Detective said:
Hope this helps. I can provide more detail if you need it. :)
Click to expand...

Thanks. Yes that does help... and more details would be most appreciated. :)

Thanks also to Lord Flashheart (and everyone else who took me seriously - I know it's difficult!). Don't argue now.

Jane.
 
It's a big subject, Jane, so if you have any specific questions feel free to ask.
The process of making plastic is to separate the gas and oil into its various components, in the case of polythene, for example, we need ethylene (poly+ethylene). Ethylene is generated from ethane, which is the slightly heavier cousin of methane and is a gas under atmospheric conditions. Ethane is converted industrially in a reaction called "cracking" into ethylene - ethylene molecules are then reacted together to form long chain polymers which is polythene.
 
Dark Detective said:
I'm going to respectfully disagree there, Flash. Polymerisation is carried out in industrial processes and are not formed within the oil. The simpler building blocks, the monomers, are. You may be getting confused with the formation of diamonds which require ultra high pressures and temperatures to form. ;)
Click to expand...

IIRC from my geology lessons (it was gcse in geology so probably wasen't teribly sophisticated) crude oil is formed when organisams die and become crushed by high pressures over a long period of time, coal and diamond form in much the sameway, the differences that produce the diffrent forms are the different componants (eg wood from marshy forests caractoristicly found during the carboniferous period were perfect for coal).

on the quetion at chemistry though I didn't do too well in my alevel in that and have fogoten most of it out of spite. but I do recall learning about oil refineing towers (thats probably not the right name for them but there you go) which if it polimers were not formed within oil and it was all monomers where dose all the petrol, deisel seperated in this process etc come from?

(apologies if I've misread your post dd, It's quite late at night).
 
Lord_Flashheart said:
but I do recall learning about oil refineing towers (thats probably not the right name for them but there you go) which if it polimers were not formed within oil and it was all monomers where dose all the petrol, deisel seperated in this process etc come from?
Click to expand...
Petrol, diesel and so forth are made up of longer chain molecules - the molecules are larger than, say, ethane and the lighter ends, but aren't polymers.
 
Hello all, on the subject of alternative fuels there is one large scale operation that I know of.

In Brazil there is a widespread use of cars that run on alchohol produced from processing sugar cane which is farmed in a massive scale there ( for the world sugar industry as well ). Many cars are build by the manufacturers in the factory to use this ( called "alcohol" variants of the standard models ) and they are around 90% of the performance of petrol.

I would guess 15% of the cars I see in Sao Paulo use this at the moment, so there is a huge base of knowledge on how these work in real life.

The fuel is less than half the price of petol since it is so cheap to produce and short of a crop blight will be infinately reproducable.

We know that fuel alcohol is easily available in volume in this place at least so is likely to be a candidate for other applications.

The question for the chemists out there is: given that alcohol contains Carbon and Hydrogen, can it be processed effectively into monomers?

thanks

Uncle Bulgaria
 
Yes, but it isn't cheap.
The thing about fossil fuels is that there is so much of them... at least there was before we started burning themn and making them into plastics.
Convereting biomass into fuel is less than 50% efficient at the moment- and making plastics is even worse...
this new process is better,
http://www.discover.com/may_03/featoil.html
but it still takes a year or so to grow the biomass at the moment...
nevertheless we will have to get used to it, as the extraction of fossil fuels will stop being economical in the next 100-200 years.

I expect genetic engineering will produce some fast growing biomass organism before long-
however the Green party don't like GM so they will probably will be against anything like that.
Which would be a shame, as it could be the answer to the energy crisis and so on.
(Benign Green Goo, we like to call it.)
 
fossil fuels are nothing special

I'm a mechanic and have worked on various kinds of combustion engines for probably close to thirty years and I can tell you there is absolutely NO reason for us to be using fossil fuels. Henry Ford's Model T was origionally meant to run on ethanol which is basically the drinkable alcohol in things like beer and whisky. It's made from grain. There are also various other alcohol-like alternatives made from things like wood, etc. I know from personal experience that I can run my simple two stroke motorcycle engine on alcohol and vegetable oil quite happily and still have fewer nasty gasses coming out my exhaust than if I were running on regular fossil fuels. Oil as we have always grown up is just nothing special. It has no magical properties that can't be replicated in some other way. I can only assume that things are the way they are because somebody somewhere keeps it that way for their private interests and damn the consequences for humanity and environment.
 
oll_lewis said:
the long chain polimers in fossil fuels take milloins of years at high pressures. presures so high that it would be financially unviable to recreate in a production line, not to mention the fact we don't have a few million years to spare.
Click to expand...

I don't have the scientific knowledge to dispute this, but I have a friend who is an expert in synthetic diamonds. They are now made on a semi-industrial scale--why are long-chain polymers such a problem?

https://en.wikipedia.org/wiki/Synthetic_diamond
 
It's not really a problem but you would spend as much energy making it as you would gain combusting it. Plus expenses.
 
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