With energy production, fossil fuels, global warming, and related issues so much in the news lately, I have a few questions that I’ve been pondering about oil and how it is used.
[li]The press seems to discuss oil in terms of energy use, but oil is also a key ingredient in various products, such as plastics. How is the scarcity of oil affecting the future of plastic and other oil-dependent commodities? Even if some other energy source magically appeared tomorrow, there would still be a strong demand for a non-renewable resource. Is there research being done to replace oil as a key component of such products?[/li][li]What about oil’s utility as a lubricant? Are there other products that can be used as easily or effectively? Of course, lard can be used as a lubricant, but it doesn’t help much in my car’s crankcase. Supposing my car ran on our new magical energy source, how could I keep the motor running without motor oil?[/li][li]There are lots of other products in the house called “oils”. Why? Does the vegetable oil in the kitchen have anything in common with the oil in the car?[/li][/ul]
With energy production, fossil fuels, global warming, and related issues so much in the news lately, I have a few questions that I’ve been pondering about oil and how it is used.
You can’t be unaware of the existence of synthetic motor oils.
I would guess that there will still be quite a bit of oil available by the time it gets too expensive to burn.
Yes, I am aware of synthetic motor oils. Do they require any fossil oil, though? Are they made entirely from renewable resources?
Nope and yep, respectively. Yeah, when they say synthetic, they mean synthetic.
But ‘synthetic’ just means that it is put together from more than one ingredient, right? Doesn’t say anything about what those ingredients are. I think that would be the relevant definition here as opposed to ‘not real or genuine, artificial.’
And there are all kinds of ‘synthetic’ things were crude petroleum is one of the ingredients of synthesis, so I don’t think it’s unreasonable to ask about this specific case.
Motor oils can be re-refined. It’s not the oil that “wears out”, it’s the additives that do, plus the dirt and contaminates that end up suspended that dictate the life of oil in the sump. By re-refining it and adding additives, it’s good to go again.
This is incorrect, synthetic motor oils are almost entirely dependent of hydrocarbons for its manufacture. When they synthetic, they mean made up from smaller molecules into a design chain not found in the base crude mix.
The base component of most synthetic lubricants is PAO or polyalphaolefin which is essentially 3 ethylene molecules stuck togeather ina complex way. Ethylene is one of the main products from hydrocarbon steam cracking, done my none other than our good friends , big oil. Useful link here.
The synthetic part comes about through the mfg process. Conventional lubricants are refined by breaking crude into its component fractions. Synthetics are made, by breaking crude down into very small molecules, then building those molecules back up again into longer designer molecules with more desirable properties than those found in the crude stream.
Now you can make ethylene by dehydrating ethanol with sulfuric acid at a high
temperature. As far as i know this is not a very economical way of doing it.
Sorry of my last post was lacking any traces of clarity, I swear it was legible when I posted it.
OK from last to first. The oils that you get from vegtables, nuts and other food products are all pretty much tri glycerides and esters, which are long chains of carbon hydrogen and oxygen atoms arranged into varying length chains, with various groups of carbon, hydrogen and oxygen at the ends, these ends pretty much define the type of hydrocarbon.
The oil you get out the ground is pretty much the same stuff, the ending of the chains and the arrangement of the hydrocarbon chains may be slightly different, but it will all break down into the same basic components.
If you take a trawl for alkanes, alkenes alkynes, esterer, aryl and carboxilic groups that should give a fair overview of the building blocks that make up organic chemistry. No doubt a proper organic chemist will be along shortly to fill in the gaps, but essentially they (vegtable and mineral oils) are made up of the same stuff.
The second question regarding running a car without lubricants. In the current designs for the commonly available car, no. There is a a fair bit of work being done on dry lubricants using techniques such as bonding one or two layers of graphite atoms onto a substrate which is then bonded onto the material that needs the lubrication. No doubt other surface technologies are work in progress.
Today it is more economical to use imperfectly ground surfaces and lubricate them with oils. In the future (sorry getting out of GQ land here) who the hell knows, it may be cheaper to manufacture super high finish surfaces with inbuilt friction reducers.
Are there any sources of lubricants. Well as mentioned up thread, synthetic motor oils are made by breaking large hydrocarbon molecules down into small building blocks, then constructing a ´better´hydrocarbon chain. Given the same building blocks can be obtained from more organic methods such as heating up an alcohol and an acid, the same motor oils could be made without a crude oil base. It all boils down to a question of economics and cost of alternatives.
Is there research being done to replace oil as a key component of such products?
I really dont know.
How is the scarcity of oil affecting the future of plastic and other oil-dependent commodities?
Of the mix of products coming out of the refineries, about 34% is gasoline, 27% is fuel oil (diesel), 9% aviation kersene and 12% heads off to the petrochemical industry. Half of this is ethylene, propylene and butylene, the rest is napatha, waxes and lubricants (1%).
Now the crude oil can be cracked down in many different ways, and the refinery mmgt are often deciding which way they want to tilt the basket, more refinary gases and naptha or boost gasoline production. They do not have a complete free hand in this, the quality of crude and the plant design have a large say. The point is petrochemicals are already (and always have been) in competition with gasoline with respect to crude input. If supplies tighten further and if demand for gasoline does not relent, then expect plastic bags to start getting very expensive.
If we find some super new fuel to replace gasoline, then all is well for petrochemicals, as mentioned the bulk of crude is used for gasoline and diesel so we dont need nearly as much for the world petrochemical industry. Now is it economical for a refinary to run without the bulk of the gasoline sales to keep it solvent?
hope that waffle was of some use.
Not very much. The oil is only a source of carbon and hydrogen atoms, no more.
We use oil to produce plastics only because it’s easy to transport and because it’s available cheaply, that is it entirely. Even if we were to run out of oil tomorrow then we would simply switch to making plastics using coal as the source of carbon and hydrogen atoms. It’s a bit more expensive, but not prohibitively so. Best guesses I’ve seen suggets that coal source polymers would be about 10% more than oil source. Not a serious cause for concern.
But there wouldn’t necessarily.
If some other energy source magically appeared tomorrow that made the costs associated with the transport and cracking of coal effectively non-existent, say fusion electric power, then the demand for oil would vanish almost instantly. Coal is much more abundant than oil and much cheaper, it’s solely the costs associated with transport and pre-processing that makes manufacturers prefer oil as their feedstock. Eleimate those costs by providing cheap energy and coal will be cheaper and more convenient than oil.
There doesn’t need to be. We perfected that technology over 50 years ago.
Yes, oil. The only difference is that it is oil produced, once again, from coal. Your car doesn’t know whether the atoms the oil contains come from oil or coal originally. Since the two products are chemically identical they will function identically. Once more the sole reason we don’t make lubricants out of coal right now is because it’s more ocnvenient and cheaper to use oil. Once that ceases to be true we wil switch over to coal immeditaely.
Why would you even try? Why not just continue to use motor oil? You do realise that motor oil is not something distilled from crude, that is a mix of almost entirely synthetic chemicals? As such why not just syntyhesise identical chemicals from coal?
Beyond both being polymers, nothing whatsoever.
I think this is one of the biggest probelms with oil dommsayers. They focus on oil as though it were the sole source of energy and hydrocarbons on this planet, when in fact it is an insignificant proportion of the total fossil fuel reserves. We use oil as an energy soucre and industiral feedstock because it;'s chepa and easy. Once it ceases to be cheap and easy we can switch over to coal almost instantly.
Thank you to everyone for the responses. This paragraph above doesn’t make a lot of sense to me.
Oil seems to be costly and difficult to get in some places. We go to the arctic tundra and into deep water to find it. We go to great trouble and expense to extract oil from inhospitable climates. If coal is so much easier and yields the same results, why go to the trouble of drilling in the North Sea or worrying about environmental damage in the the Alaskan wilderness?
As we’ve seen recently, coal seems to be a risky proposition to extract, too. Many miners are killed each year in the United States alone. A coal mine is among the most dangerous places in the world to be. Certainly, I understand that people die in all sorts of occupations and that danger is not a reason to abandon something, but coal doesn’t appear to be all that easy to get, at least not all the time.
So, can gasoline be refined from the more abundant coal?
My car can operate on E80 fuel, which is part alcohol and part gasoline. However, the owners manual warns that the energy content of E80 is not as high, so expect poorer mileage and poorer performance. Does this mean that organic fuels cannot be competitive will oil? If vegetable and mineral oil are essentially the same stuff, why aren’t we using vegetable oil? (Perhaps unrelated, but why can I safely eat vegetable oil but not eat or drink mineral oil?)
Yes , fischer tropsch method, used by Germany in WWII and may see a resurgence of new investment.
Incidentally recently BP and Rio Tinto (big mining company) announced they would work together on clean burning coal. Pure speculation but I wonder if they are also looking at improving the FT or something similar
It is a matter of economics and supply and demand. Can enough organic fuels be produced, and not conflict with land use for animal and human food? Probably GD territory there.
Well they are made from the same building blocks, that does not mean the end product is the same. I would not like to have a lug full of crude, although there was a thread somewhere on using mineral oil for medicinal purposes.
Why not use vegetable oil, because crude is much more plentiful and cheaper.
Well, even with the fantastic expense of constructing a pipeline from Prudhoe Bay to Valdez, and building those offshore platforms and so on, gasoline made from crude oil is still much cheaper than synthetic gasoline created via the Fischer-Tropsch process. If prices for crude oil continue to increase, and prices for coal stay flat, then at some point synthetic gasoline becomes cheaper than regular gasoline. Note that the Fischer-Tropsch process isn’t cutting edge, it’s been around for a long time and was used by Germany during WWII because Germany had a lot of coal but no oil. Since there’s a world market for crude oil, it doesn’t matter much that the US is packed with coal but only has a medium amount of oil, because we can simply buy cheap oil from other countries, and that cheap oil is still cheaper than what we could make from coal.
As for the energy content of fuel, it depends on the product. Gasoline–mostly octane–has more energy per liter than ethanol. So the comparison shouldn’t be price per liter, but price per energy. As to why your gas station adds ethanol to gasoline, it’s essentially a subsidy for Archer-Daniels Midland.
But vegetable oil has the same energy per liter as diesel fuel. Why don’t more people use vegetable oil? Because vegetable oil is a lot more expensive per liter than diesel fuel, UNLESS you can get vegetable oil that was just going to be thrown away anyway, like the used leftover vegetable oil from restaurants. You could go down to your local grocery store, buy bottles corn oil, and pour it directly into the tank of your diesel car, and it would run. But it would cost a lot, and generally you want to either add a bit of detergent to the vegetable oil which makes “bio-diesel” so you can run it on a standard diesel, or make a few simple modifications to your engine so it can run better on straight vegetable oil.
The answer to most of your questions is simply cost. How much does it cost to provide a particular product vs another product? What would be the price if the scale of supply or demand changes? If we’re converting megatons of corn to ethanol, what does that do to the price of corn? If we’re producing megatons of ethanol, what does that do to the price of gasoline? And none of these costs are static, they vary depending on a couple thousand factors.
Somehow, whenever I imagined what would happen if we made fusion power plants work, I never pictured a future of massive coal mining. If we could have virtually unlimited electric power from a clean, renewable source, couldn’t we synthesize whatever hydrocarbons we needed starting with hydrogen and carbon?
Sure you could, with unlimited fusion power we could synthesize octane out of any feedstock you like, even H2O and CO2.
The only trouble is that it’s not likely that fusion power will be essentially unlimited, because even if a fusion plant can generate arbitrary amounts of electricity it’s probably going to require a gigantic capital investment, and even if the only fuel is seawater the plant is going to have other operating costs. And even if fusion power provides cheaper electricity that doesn’t mean it would be economical to synthesize octane rather than refine it from natural sources. Even if the cost of the energy input for your synthetic octane plant is zero (which it wouldn’t be even with fusion), the total cost to manufacture and distribute that octane would not be zero. It would have to compete with other fuels, and it could easily be much more expensive than regular octane.
But the point is valid that octane is used as a transportation fuel for more reasons than cheapness, and even if no more natural octane is pumped out of the earth it would still be possible to manufacture octane from other sources. The question is what that would cost, and whether that cost is worth paying. Octane can therefore be considered an energy storage medium rather than just an energy source, you can use electrical power to charge a battery that powers a vehicle, or use electrical power to synthesize octane that powers a vehicle, the battery and the octane aren’t energy sources but energy storage. But what energy storage mechanism we use in future vehicles–hydrogen, methane, ethanol, octane, diesel, battery or whatever–would be an economic question. What can deliver the best performance for the lowest cost, and for what externalities, and who pays for the externalities?
Not that I know of. They are working together on a current project for carbon capture/sequestration for a new plant in Australia, and that’s what most of the fuss is about. It’s a great first step because AFAIK 90% carbon capture + sequestration has never been applied on a unit as large as the one they’re planning (500MW or so).
Ah cool, thanks, I was idly wondering what they were up to. So BP has the holes to stuff the CO2 into and RioT provides the coal.
Totally off topic but are there any specific coal types that are cleaner burning with either less particulates or CO2 produced?
Sadly, that’s a large a part of my career for the last 15+ years. I’m beyond the point of giving any answer I feel good about other than “yes, yes there are.”
But let me try - limiting my answer just to the CO2 aspect of it, and not dumping one of my books onto you, there are two aspects to it. First, there are some coals which have a slightly better H/C ratio than others, but generally speaking, until you get down to lignites (which have their own serious problems) you don’t tend to have the H/C ratio change by much.
Second, the efficiency by which the coal burns is important, because at lower efficiency levels more coal is required. High moisture content creates latent heat losses, which can cause as much as 3-8% efficiency loss overall. A very high level of fixed carbon can lead to high levels of unburned carbon, between 1-3% (typically, with good coal, less than 1%). And of course depending upon the ash mineralogy and constituents, slag buildup in the furnace during combustion can reduce heat transfer, leading to increased latent heat losses (typically, these are 3-5% of total efficiency loss).
Now in terms of particulates, sulfur pollution, NOx, mercury, arsenic…erm, that’s about a few hundred page discussion, probably.
You already answered your own question. Coal isn’t all that easy to get, at least not all the time. As we’ve seen recently, coal is a risky proposition to extract, too. Many miners are killed each year in the United States alone. A coal mine is among the most dangerous places in the world to be.
Once you factor in the that oil is much cheaper and easier to transport ( an unmanned pipeline vs. the equivalent of 200 trains a day) and much cheaper to crack then you can see why we use oil. Oil is used because it’s cheap and easy That’s it. If we had to abandon oil for some reason we would switch over to coal in a minute.
Yes, but it wouldn’t be the starting point in the real world. First we would exploit the 2, 000+ years worth of resources that are found in surface oil shale and tar sands. That is a much easier, cheaper and convenient source of gasoline.
Not only can’t they be economically competitive, they aren’t even energetically practical. By the time you make the fertiliser, operate the irrigation pumps, run the tractors and power the distilleries and so forth you use more gasoline making a gallon of ethanol than you actually replace with ethanol.
IOW using ethanol burns more ethanol than just burning gasoline.
They aren’t essentially the same stuff. Everybody in this thread has said this. Aside form both being polymers they have n similarities at all.
Because vegetable oil is a fatty acid and utilisable as food source. Mineral oil is a long chain alkane and aside from being totally indigestible will dissolve your cell membranes.
Well, it goes a little further than that. They’re both carbon-backbone polymers and both have a low polerization. They have comparable energy content, and are both liquid at room temperatures. Both are lighter than water, and will not dissolve in it, and both will produce translucent stains on paper. But yeah, they’re different in the details.