Fossil fuels vs. renewable energy sources

[Nathan]

There's 2 factors to that.

-America has a "bigger is better" mentality. This is partially because the country's so big, and there's a lot of wide open space that Europe simply doesn't have. We also don't have 500 year old cities with narrow streets.

-Europe has low-sulphur diesel fuel, and they're willing to use it. America is crippled with eco-weenies who won't allow us to have diesels, even though we get the low-sulphur fuel here next year.

I wasn't aware that you guys didn't use diesel... By far the majority of cars here run on petrol though. Diesel engines are known to be more efficient, but people find them irritating because they are (or were) larger/less powerful than their petrol counterparts. Now that this is not so much the case any more, they've grown in popularity.


I'd have thought that having a larger country (and larger distances to drive) would cause you to be very miindful of your fuel consumption. I don't understand why driving further would make you get vehicles with lower fuel efficiency.

[Prebe]

I'd have thought that having a larger country (and larger distances to drive) would cause you to be very mindful of your fuel consumption. I don't understand why driving further would make you get vehicles with lower fuel efficiency.

Good point Nathan

Oh, and let me tell you why I think that oil companies are not so interested in developing new renewable energy sources, as they would have it seem: Because they are renwable. Because you can sell people a windmill, but you can't sell them wind!

[kevinswatch]

I know what Photosynthesis is.

But you're right, that makes sense. It just slipped my mind for a second.

Although there would still be a problem with the unbalanced need of fuel. Basically, in cities, we'd be burning a whole lot more fuel than in the country (where this biofuel would be grown). So this could lead to some dangers.

(I'm an environmental engineer...if anything I should know how environmental input/output systems work. ) Heh.-jay

[Loredoctor]

Because you can sell people a windmill, but you can't sell them wind!

Duh! They will make wind and sell it!

[Cail]

Prebe, the short answer is yes, the eco-weenies (and I never meant to imply that you are one) have convinced the public that nuclear power is evil, and therefore we haven't done what the French have done. Nuclear power, for lack of a better phrase, kicks major booty. But after the 3 Mile Island hiccup, we don't want to play with it anymore.

Nathan-Yeah, you're right to a certain extent. You'd think we'd want to save gas on all those long-distance trips, but what we really like is being in a big "safe" comfortable vehicle.

We don't get all the cool stuff you guys get. We don't get the Smart cars, we don't get the Mondeo or the Fiesta, we don't get Vauxhall or Opel. With the exception of Mini, you can't buy a small luxury car from an American brand.

[Prebe]

Although there would still be a problem with the unbalanced need of fuel. Basically, in cities, we'd be burning a whole lot more fuel than in the country (where this biofuel would be grown). So this could lead to some dangers.

I wouldn't consider that a problem. Oil products are not mainly used where they are produced either. The main problem with biofuels is the production speed, and of course someone will have to make the processing plants. I don' think private contractors are ready to roll up their sleeves and duke it out with Big Oil. This is why (at least to begin with) biofuels should be a supplement, and why the first processing plants should be government driven, because competition would not be an issue.

Cail: So we will have to agree to disagree. You think that the eco-greenies are hindering the progress of renewable energy. I will agree as far as they might have had some influence on the construction of new nuclear power plants and oil refineries (non-renewable energy). But when it comes to renewable energy I am convinced Big Oil is the major reason that the progress has been so slow. Somehow that seems more logical to me for the reasons stated above.

What do you think about the eco-greenies effect on the Monsanto industry? And where did you hear that hydrogen production costs massive amounts of energy?

[kevinswatch]

^Well, all I meant from that is just to restate a current problem that we already have in cities. The large number of factories and cars in cities leads to a large buildup in gases and smog and other crap that causes all sorts of health problems. Places like LA and Mexico City already have this going on.

after the 3 Mile Island hiccup

That, and, the small issue of the fact that nuclear plants generate a crap load of radioactive waste, which, currently, we have no good method of dealing with that stuff right now. It'd be nice if we put some more research money into good methods for getting rid of nuclear waste. Because right now, "burying in the ground" just isn't the best long term solution. There are just too many problems with that, such as radioactive material leaking into the groundwater. -jay

[Cail]

No question Jay. We need to spend some serious dough to figure out ways to dispose of nuclear waste.

[Prebe]

Jay: Alcohol as a biofuel is practically parcticle free as far as I know.

[Cail]

I don't remember, how does alcohol compare to gas as far as energy per gallon? I know you can make a ton of horsepower with it (it's what dragsters run), but how is it on efficiency? And how much energy does it take to produce it?

[Prebe]

They should have some experience in Brazil. I will look it up. But why hasn't anyone asked the question what it costs in energy to refine oil?

[Cail]

Simple, that's a known. I could buy gas for $1.50/gallon last year that'd push my 4000# pickem'up truck 17 miles. Fossil fuels are incredibly efficcient.

[Prebe]

But why hasn't anyone asked the question what it costs in energy to refine oil?

I wasn't asking the fuel efficiency. I was asking what the energy cost of oil refining is, just as you asked what the energy cost of producing alcohol is.

[Cail]

But I gave you the answer. At $1.50/gallon the oil companies were making record profits.

[Prebe]

True. But I was thinking energy. How many calories does it take to convert crude oil to gasoline? Price is not indicative of production effectivity, as the petrochemical industy runs on their own products. But don't worry, I'll look it up.

[Cail]

Good question, but I think it's pretty obvious that if the oil companies are making money selling gas for $1.50/gallon, or $.95/gallon 3 years ago, they're more than covering the cost of refining.

[Nathan]

Alcohols are just the same as hydrocarbon fuels but with their own oxygen built in! It makes them burn more cleanly, as they automatically have a richer oxygen supply, but their energy:mass and energy:volume ratio will be poorer as oxygen is rather a large atom compared to Carbon and hydrogen.

Depending on the number of hydroxyl groups in the alcohol you could end up doubling the mass of the molecule.

[Prebe]

Nathan: The O has already reacted with (partially oxidized) one of the carbon atoms. It is no more, than - as you say - a waste of space. It does not make combustion cleaner (EDIT: According to the the link below it might. I just can't see the chemical logic of that). However, It is correct that you will need less molecular oxygen to complete combustion, but that is because the presence of the alcohol group means, that the compound is already partially oxidized or "combusted". So needing less oxygen is simply because you can't squeeze as much energy out of it, as the coresponding hydrocarbon (ethane). The real advantage of the oxygen atom is, that it polarises the molecule making hydrophilic interaction possible, making the compound much more dense (a liquid as opposed to a gas), and thus much easier to handle and transport.


Fuel efficiencies (this is the easy bit, the hard bit is calculating/finding the exact production costs in terms of energy and money).

Ethanol compares reasonably well to gasoline as a transportation fuel. Like gasoline, it is in liquid form, making it easy to deliver, store, and pump. Gasoline has an energy value of approximately 124,000 BTU per gallon, about 30% more than ethanol and 80% more than methanol. The practical effect of alcohol's lower energy content is to decrease driving range. However, the alcohols have higher octane ratings than gasoline and its use allowed for the replacement of lead-containing anti-knock agents. This allows for more efficient combustion and offsets alcohol's lower energy content to some degree. In addition, more efficient combustion generally results in cleaner emissions.

I'll need to double check these numbers of course.

they're more than covering the cost of refining.

I am sure that is true.

[Prebe]

The chemical potential, or Gibbs free energy, of a substance is equal to its chemical exergy.

Exergy of crude oil refining: 14.0 - 43.8 %
scitation.aip.org/getabs/servlet/Getabs ... s&gifs=yes
And add to that, that the power input into the process is high quality fuel oil.

Exergy of water electrolysis: 62 - 84 %
www.inderscience.com/storage/f911163247581012.pdf
The power input here is electricity, that can be produced by renewable sources.

So, I wonder where the argument of "tons" of energy required for hydrogen fuel production comes from.

I know that these analyses do not take the transport and pressurisation of hydrogen into account. But as I argued earlier, I see hydrogen used at a decentralised energy storage compound, and not as a fuel for vehicle propulsion. Here I am for the use of biofuels. The sources on exergy of biofuel production are many and confusing to say the least, so I will get back to you with more info on that, once I have established an overview.

Oh yes, and guess what? Free hydrogen is used by the ton in crude oil refining. Big refineries make it by catalytic conversion of natural gas, but smaller refineries have it delivered. So somewhere, in oil refining of all places, it has been found sensible to pressurise and transport free hydrogen.

[Cail]

In English, please.