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Zero-emission Power Plants Proposed
ckbreckenridge writes "Supercompact, superfast, superpowerful turbines called ZEPPS (zero-emission power plants), designed to combat global warming, could help produce the electrical power needed to keep up with 21st century demand. They would consume methane and oxygen and produce liquid carbon dioxide, which could be sequestered underground. The current electricity grid would need to be replaced by a 'supergrid' across the USA, says Jesse H. Ausubel in The Industrial Physicist. Work on such a system should start as soon as possible, since CO2 levels leaped up 2 ppm in the past two years as global warming becomes more of a reality."
The problem with all of these is you have to worry about the re-emergence of the CO2. Limestone seems like a good option because you just have to keep it dry. The downside is that limestone is heavy and even though the production is exothermic, producing lime has not been worked out. Pressurizing CO2 and storing it underground works, unless it leaks out. Then you have the same problem. Liquid bubbles are good if you have a very high pressure place to store them (the ocean), but the long term effect is acidification of the ocean and exhaustion of the carrying capacity (estimated to be around 1000-1500Gtons, we produce around 3Gtons/year).
There aren't any easy answers. However long term, since coal is about 57% of current electricity in the U.S., it's not going away. What carbon sequestration will do is allow us to bridge the gap economically and technologically between high and low carbon fuel sources.
I'm a big fan of wind, but there are still lots of hurdles.
-- Bird in the Bush: The Renewable Energy Blog http://www.birdinthebush.org
http://www.netl.doe.gov/publications/proceedings /01/vision21/v211-5.PDF
Chris Williams clw7500nc@gmail.com
It sublimates directly at atmospheric pressure. It will form a liquid at high pressures however.
Only in a Slashdot fantasy can a Slackware install turn into several hours of sex . . . . .
I know this isn't a popular option, but there is only one way left to combat CO2 emissions without winding the planet back to the stone age.
It's nuclear power. There is no other technology available that has sufficient output, whilst not outputting CO2 that will put the Florida Quays any further underwater.
The common argument in return is saving CO2 isn't much use if you make the planet uninhabitable due to reactors melting down. Well, the Chinese, with some help from the Germans, have very kindly solved this problem for us. Go check the link out - it's to wired.com - they have developed a nuclear reactor that doesn't go critical when the coolant system is switched off.
We can save the planet, if we're willing to get over the Cold War era stereotypes.
Iran has endorsed
The CO2 is a liquid because of the pressure, not because it is really cold.
"Warming it up" won't make it boil.
A friend who worked in the Hazardous Waste disposal industry lamented the ignorance of many protesters who came out to his site and harrassed the workers. They didn't know the difference between Hazardous and Toxic waste. CO2 is not toxic. In high concentrations it can be harmful (depending on the lifeform), but that is the definition of Hazardous. Toxic means it does harm even in small concentrations.
Example:
1,000 gallons of horse urine if dumped on a field would probably kill the grass, but if dilluted and spread over time it would not.
1 milligram of plutonium spread on a field would kill the grass, no matter how you dilluted it and grass wouldn't grow again for a long time.
I'm sure I didn't explain this as well as he could have, but I hope you get the gist of it.
A feeling of having made the same mistake before: Deja Foobar
>I thought carbon dioxide sublimates, as in goes from solid to gas with no liquid step. Or, if it has a liquid stage, its only under very specific conditions of temperature and pressure.
It's pressure that makes the difference. At atmospheric pressure CO2 doesn't have a liquid phase. At higher pressures it does. In fact, the way you make dry ice (at least used to be) taking the pressure off some liquid CO2, letting some evaporate to chill the rest into a solid.
The proposed power plants operate at high pressure including the exhaust stream. So all you need to do is cool the exhaust and you have liquid CO2.
For sake of reference, the suffocation incident was at Lake Nyos in Cameroon and is documented at http://www.snopes.com/horrors/freakish/smother.asp . 1,746 people killed in a matter of minutes... evidence of how scary Mother Nature can be. Although, to be fair, death was apparently very swift and likely painless.
This sig has absolutely no significance and serves only to take up screen space and waste the time of the reader.
What a rosy view of the future!
NO. 300 gigatons of CO2 cycle through the environment every year. In a closed cycle.
But every year, humans add an extra 6 gigatons to that cycle that was not there the previous year. We do this by taking carbon from deep underground (in the form of oil) and burning it to release that CO2 to the atmosphere.
Natural processes do not change the global CO2 balance, at least not on the short time scales that humans are capable of changing it.
CO2 also doesn't explode, so it's safe to store.
... neither does nuclear waste. What CO2 does do, that nuclear waste does not, is roll down mountains as a cloud, smothering entire villages.
Um
"Because Science" is one step from "Because old book". Try "Because of my experiment testing my falsifiable assertion".
How is this diffrent then toxic waste from nuclear plants being stored under ground....
Much more hazardous, especially on an immediate basis.
Liquid CO2, pushed down injection wells under pressure, occasionally springs a leak. When this happens you suddenly get a giant bubble of CO2 on (and in) the ground, displacing the oxygen and killing everybody and everything (even plants if it persists in the soil long enough) for miles around.
This has happened when CO2 injection was used to pressurize oil wells to squeeze more oil out of the gound.
A similar phenomenon happens naturally (though fortunately VERY rarely) when largely CO2 volcanic gasses vent into a deep still lake (such as in a volcanic crater). The gasses disolve, carbonating the lower waters. Then suddenly something disturbs the water and some of the carbonated water comes up and starts to bubble - rapidly "turning over" and boiling out the CO2 in the rest of the lake in a matter of minutes and releasing a similar ground-hugging toxic bubble.
Think of a shaken soda can the size of Lake Tahoe.
if we continue storring all this wouldn't eventually run out of place to put it?
Nuclear, at least, takes up very little space and decays over years/centuries/millenia (depending on the isotope - generally the hotter the faster). Some of its components are also useful and can be separated out and put to work. Others can be "burned" in nuclear reactions into less hazardous and/or more useful material.
That's not to say it's safe or good stuff. Some of it is horrid. But "running out of room" isn't the problem. (Keeping it in its room until it promises to be a good little kid and MEANS it is the problem.)
Bantam Dominique roosters crow a four-note song. Once you've heard it as "Happy BIRTHday" you can't NOT hear it that way
No, we won't suddenly be growing wheat in fucking north dakota, the soil isn't right for it.
Wheat growers in North Dakota beg to differ.
You can never go home again... but I guess you can shop there.
No politician? Granted, $7.2 million isn't a huge amount of money, but it was enough for Bush to bring it up during the debates. I think the fact that it would increase agriculture jobs is just as important as helping the environment.
You have enemies? Good. That means you've stood up for something, sometime in your life. --Winston Churchill
Problem is, every so often, the carbon dioxide gets out. And lots of people die. Now, there are degassing projects which release the gas from the lakes into the atmosphere in a gradual controlled process.
Degassing
"Reality is that which, when you stop believing in it, it doesn't go away." - Philip K. Dick
This guy talks about 3000 RPM as a novel, high, shaft speed. Standard power generation turbines normally run at 3600 RPM, or sometimes 1800 RPM, to synch with the power grid. Modern microturbines run up to 96,000 RPM. (Yes, at last, Capstone Turbine isn't vaporware any more. You can actually buy a 60KW generator from them. This is an option worth considering if you need backup power for your data center.) Only 24% efficient, though. General Electric's most efficient gas turbines have reached 60%. (Big turbines are more efficient than little ones.)
Turbine technology is up against materials limits. Vast amounts of effort (many billions of dollars) have been put into finding better materials for turbine blades, because this limits aircraft performance. Current blades are single crystals of metal, often with a ceramic coating. Pure ceramic blades have been made, but have tensile strength and brittleness problems. The turbine this guy is talking about requires materials way beyond anything that exists today.
If it's thermodynamically possible to build a big machine of the type this guy is talking about, it should possible to build a little one right now.
Neo-conservatives (in the derogatory sense) are not conservative fiscally. Their plan is to increase government spending in the form of corporate welfare while cutting taxes. The theory is that this will cause the economy to grow so much that the resulting deficit doesn't matter. They also believe in restricting civil rights; for instance granting the executive branch powers to lock people up without trial. They believe in solving international problems by going to war with the countries that are causing those problems.
To some degree these are valid attacks on the current Republican administration. Many people are wondering where the small-government Republicans of the '90s went.
I have seen the future, and it is inconvenient.