[Waaaaay OT but who cares its cool] We might be able to turn anything in Oil soon.

[Umbran]

Okay, we seem to have some misinformation about carbon...

The problem with fossil fuels is not that they release carbon. The problem is that they release carbon that had been taken out of the system. The carbon in fossil fuels has been out of circulation for millions of years - as far as the current atmosphere is concerned, it is a "new" source.

Burning currently active biological stuff (like this "turkey oil") doesn't have that problem, as they are part of the current carbon cycle. The carbon in the turkey comes from grain. The carbon in the grain comes from the atmosphere. So, carbon goes from the atmosphere, into the grain, into the oil. You burn the oil, putting the carbon back into the atmosphere. And the next generation of grain takes it right back out again.

So long as you ultimately get the carbon from currently living plants, the net release of carbon is zero. This is a good thing, greenhouse-wise.

About fuel cells:

Standard electrolysis of water is not the only way to get hydrogen. Recently, I read (I believe in Scientific American, I'll see if I can find the reference) a report about a new process - you take a sugar solution, heat it slightly, and pass it over a catalyst, and you get hydrogen and oxygen coming off.

Note that this is a catalyic reaction. Rather than take electical energy (from a fossil or nuclear fuel) and storing it as chemical energy (in the form of hydrogen and oxygen), you are taking the energy in the sugar, and converting it into energy in hydrogen and oxygen. The energy for this process comes from the sun, via sugar cane. So long as it doesn't take too much energy to isolate the sugar from the plant, we effectively have solar-powered cars

DM_Matt: Where do your numbers on Uranium reserves come from? They sound very, very short to me. I think there's a lot more Uranium energy liying around than your numbers suggest.

Fission power does bring up the issue of nuclear waste. As DM_Matt said, the spent fuel of our current reactors can be recycled. Much more energy can be extracted, and the final products are not radioactive for nearly as long.

Why don't we recycle, then? Because back in the Carter Administration, when nuclear energy was just starting to take off, someone asked the question - what happens if a terrorist or aggressive nation gets a hold of the spent fuel? Boom! So, in order to decrease this risk, they decresed the number of hands the Uranium passes through by making the recycling illegal. This leaves us with an ugly waste issue. This part of the thing can be solved by simple legislation.

There's another waste problem, though, that isn't easy to solve - the reactor itself becomes radioactive. At the moment, there's no "good" solution for this problem. The reactor is typically carted off piecemeal into a landfill.

Nuclear fusion has no fuel-waste issue. A fusion reactor takes in hydrogen, and puts out non-radioactive helium. Heluim has no known nasty environmental effects of which I'm aware (other than making people talk like a duck). You do still have some problem with the reactor becoming radioactive, but to a much lesser extent than with fission reactors. The only problem being that nobody yet knows how to control a fusion reaction on a scale large enough to be useful.

 

[Norfleet]

Helium is not KNOWN to have any detrimental effects, because much of it tends to easily escape into space. There's no telling what might happen if massive quantities of helium were to be ejected into the atmosphere, and while hydrogen may feel abundant now, the day will come when we must save our hydrogen, or start stealing it from other planets.

 

[MeepoTheMighty]

Helium is not KNOWN to have any detrimental effects, because much of it tends to easily escape into space. There's no telling what might happen if massive quantities of helium were to be ejected into the atmosphere, and while hydrogen may feel abundant now, the day will come when we must save our hydrogen, or start stealing it from other planets.

That's the most ridiculous thing I've ever heard. If the day comes when we start running out of hydrogen, we're seriously boned. It's not that easy to destroy a proton, after all.

As for the helium in the atmosphere, the vast majority of it would escape into space. If anything, the earth currently has *much less* helium than it should, given current earth-age estimates. There are a few theories as to why this is, but suffice to say that we're in no danger of killing ourselves with helium.

 

[DM_Matt]

DM_Matt: Where do your numbers on Uranium reserves come from? They sound very, very short to me. I think there's a lot more Uranium energy liying around than your numbers suggest.

There most likely IS. This only accounts for the known accessable reserves and assumes that 100% of the world's energy would come from nuclear power. As it stands, 20% of electricity comes from nuclear power plants (Some places more than others, with France in the lead with 79%), and much less other rescources.

That stat came from multiple sources that were included in an Environmental Policy course I recently took.


Oh, and a random fact about helium: Almost all harvestable helium happens to be in the US. thats why the Germans had to use (combustable) hydrogen for their blimps.

 

[Will]

Little misunderstanding there, maybe...

A carbon sink is a reservoir of carbon, often important in the carbon cycle. For example, carbon dioxide is bound up in the deep ocean. Some worry that if the world heats up, this sink might start releasing its stored carbon.

Landfills and plastics are not a 'sink,' at least not in a short-term sense. (As in less than hundreds of thousands - millions of years)

This technology, however, would make landfills and all of civilization a carbon sink, a safe reservoir of carbon resources that cycle through our technology. Which is a good thing. What we have now is a consumer system, dangerously linear.


Oh, a note about infrastructure. The article notes that gas/oil companies _like_ this technology and will likely invest in it. Why?

Because refining produces a lot of waste oil, and mining often leaves behind large quantities of tar sands. These resources are unusable with conventional technology... but surprise surprise, thermal depolymerization can convert both into useful hydrocarbons.

 

[Wulf Ratbane]

[edit] I'm just in a bad mood today.

 

[buzzard]

Not doubting you, but what are some? Expand the minds of your fellow posters already.

Oh, say all plastics and maybe 50% of chemicals used. That's all. No big deal. While steel still remains the largest single use substance (well I'd have to check against concrete and wood, but this is hyperbole, so forgive me) the world would come to a screeching halt without plastics.

buzzard

 

[buzzard]

There's another waste problem, though, that isn't easy to solve - the reactor itself becomes radioactive. At the moment, there's no "good" solution for this problem. The reactor is typically carted off piecemeal into a landfill.

Actually I worked on a project on this subject. The real problem you have in nuclear reactors, in terms of the reactor becomming radioactive, is the stainless steel pipes getting contaminated with radioactive salts. Iron itself doesn't become a very radioactive substance (iron, in fact is the dead spot in both directions for nuclear reactions, more energy is required to fuse or fission iron than is released in the process). Thus if you can get the radioactive salts off, you can re-use the metal. At Sandia I worked on using Electro Slag Remelting to melt radioactive stainless steel pipes and trap all the radioactive salts in a slag and produce pure stainless steel. The slag still has to be disposed of, but by mass it is a small fraction of the mass of the pipes. Also it can be re-used untill you have concentrated a good amount of the radioactive material in the slag. The process is currently in trials in Russia. I imagine that the reactor vessel isefl might managed to become a radioactive isotope of iron, but this process will solve the problems of the pipes in the heat exchanger, which, by mass, is a much bigger problem.

Also, for future nuke technology, there are the pebble bed reactors which use noble gasses as the heat exchange media, so the pipe issue goes away altogether.

buzzard

 

[buzzard]

Helium is not KNOWN to have any detrimental effects, because much of it tends to easily escape into space. There's no telling what might happen if massive quantities of helium were to be ejected into the atmosphere, and while hydrogen may feel abundant now, the day will come when we must save our hydrogen, or start stealing it from other planets.

Just to back up Meepo here, worrying about helium is wholy ridiculous. It is an INERT gas. It CANNOT react with things. You cannot, make it react with things. Heavier inert gasses(argon, neon, etc) can be forced to react with halides under some circumstances, but not helium. The only way helium could kill a person is if you fill a room with it to the extent of driving off all the other gasses.

buzzard

 

[Conaill]

A carbon sink is a reservoir of carbon, often important in the carbon cycle. For example, carbon dioxide is bound up in the deep ocean. Some worry that if the world heats up, this sink might start releasing its stored carbon.

Landfills and plastics are not a 'sink,' at least not in a short-term sense. (As in less than hundreds of thousands - millions of years)

This technology, however, would make landfills and all of civilization a carbon sink, a safe reservoir of carbon resources that cycle through our technology.

A carbon sink is not just a reservoir! It's a reservoir that has a net uptake of carbon from the atmosphere. That's why it's called a "sink", and not a "source".

Examples of carbon sinks are growing forests (locks up lots of carbon as biomass in the tres and soil - doesn't really take carbon out of the carbon cycle, but at least out of the atmosphere), pumping CO2 into abandoned oil wells, absorption of CO2 in the oceans, etc.

Anything that sequesters carbon - like plastic in landfills that won't deteriorate for millions of years - could be considered a sink (although indirectly - it sequesters carbon that would otherwise wind up into the atmosphere, e.g. by burning trash). However, putting this already sequestered carbon back in the carbon cycle (by making fuel out of it, and then burning that fuel) would make it a carbon source! Just like pumping oil out of the ground is a net carbon source.

Not that I think it's a bad idea to do something about landfills mind you. Just wanted to get the semantics right...