Help me understand "clean coal"

[margotb822]

What makes it a myth? Why doesn't it work like people advocate? Why does Obama support it?

[Idealism]

1. Its an oxymoron?

There is no such thing as clean-burning coal, it all produces harmful emissions, from what I've read. Obama supports it because its a good sounding political phrase? There have been efforts to make it burn cleaner but I think its very costly (which is why most new plants built are still not geared towards the "cleaner" variation).

[NMDemDist2]

2. as far as I can tell, it's the same as a Hydrogen car

theoretically possible, but a long way from ready for real world application

[XemaSab]

15. It's not that far off

Maybe a year?

But there's still a lot of kinks to work out.

[Radical Activist]

3. The coal industry is extremely powerful in Illinois.

They employ a lot of people and they have good propaganda. That's why Obama supports it. Its nice to be able to think that with the right technology they can keep using coal without the pollution but it hasn't been proven to work and the technology they do have is much more expensive than wind or solar.

[kristopher]

4. What makes it a myth?

It won't work.

Why doesn't it work?
Fossil fuels are mostly carbon. In order for it to work, we would have to mine the carbon, refine, ship, and then convert into thermal energy, at which point all that carbon is released, only now it is locked with Oxygen and weighs about 3X its carbon only weight and volume.
Now we need a place to sequester it. Where should that be? There are problems with specific sites and such, but some of them would probably word. Trouble is, we need as nmuch room to store it as it occupied before extraction from the ground. You know that whole big system we have for getting the original fossil fuels out of the ground? Now we need a similar infrastructure to put it back.

An oh, did I mention that all of this takes energy and that the amount of energy we get in excess of the amount it takes to mine, refine and transport the stuff is rapidly dropping to an uncomfortable low level. Meaning of course, that if the energy load to prepare transport and sequester as high as it appears at first blush, there will be damned little energy left to do anything but mine energy ans sequester the carbon.

Obama supports it because a lot of ery powerful people own a lot of coal mostly. They are getting ready to lose in a large way. He is promising support for investigation, but he must know it wont work. The research money gives the resource owners hope, is my take on it. JIMHO

[Veritas_et_Aequitas]

5. It's somewhat complex.

Clean coal technology catches some of the pollutants produced by using coal. It's gotten better over time and today's clean coal technology is notably more clean than that technology of 30 years ago. However, it still does pump out a significant amount of pollution.

Advocates point out that the technology is still developing and improving over time. With use and funding, it could eventually get to the point of being able to capture 90+% of pollutants.

Detractors point out that the technology is further away than advocates lead on and believe energy should be put into improving renewable energy technologies.

Last week there was a good segment about it on Day to Day on NPR. Check it out. I think it was on last Friday.

[margotb822]

6. Interesting, thank you

I will definitely check that NPR segment out.

[HillbillyBob]

18. And it still destroying huge swaths of what now USED to be one of the most

Beautiful places on earth in Appalachia, destroying lives and streams that become rivers that we use for crops and to drink. The mines use very few workers so there is not much employment.
I wonder how many people does it take to set out dynamite. or bulldoze the remains into valley fills that are habitat and farm fields?
Poisoned water, dead fish and plants at the very bottom of the food chain, that lead eventually right to our plate.
There claims there are plans to normalize it or there were before boosh.
When I grew up there, you could go by an area that had been strip mined see that they would leave pieces of equipment around to say oh we are not done here it is still a going concern they never did clean anything up and that was when there were laws and on occasion there would be an ittybittytiny bit of reconstruction, I have no been home in some time but the last time I was and from what family tells me things are worse than ever since boosh and crooks stole the White House.
I would go do something but all I can do is advocate, I am too sick to go shoot at em. then there are the slag ponds. One burst a couple decades ago in Ky wiping out a town. There are a bunch more that are unstable overfilled and poorly constructed that will let go it is only a matter of time.

[OhioBlue]

7. It is a myth b/c it isn't really clean

it is a process to make it burn "cleaner" than it currently does while burying the carbon. My guess is that Obama supports it b/c it isn't exactly feasible to go to all clean/all renewable in a short time frame or without serious changes in the way we live - and there are many people whose livelihoods depend on the coal industry.

I hope that Senator Obama does use his administration to stop the mountain top removal process and hopefully use some of the areas in WV and other areas where MTR has been done for wind energy - which would hopefully produce clean energy and provide local jobs.

[RaleighNCDUer]

8. There is no such thing as 'clean coal'.

Only 'cleaner coal'.

[dbonds]

9. Same as Free Energy, or the Tooth Fairy

[madokie]

10. Here is an explanation of the process and a couple links

This first link is to this article here the one at the end is another article on the same subject.
When I've asked about this here I've only been ridiculed for bringing it up as can be seen from the replys you gotten so far. I gave up on trying to get any dialoge going on this. All of our coal power plants could be convert to using a gasifier with a minimal of cost in relationship to a complete new plant from scratch. the gasifier burns coal with close to a 60 percent reduction in co2 produced to begin with. Even without the carbon capture it would be good for us to use this technology as we're building out our alternates. dm

Some good reading here and at the other link too. I'm turning in now but maybe we can share some ideas on this technology later.


http://www.fossil.energy.gov/programs/powersystems/gasification/howgasificationworks.html

How Coal Gasification Power Plants Work


The heart of a gasification-based system is the gasifier. A gasifier converts hydrocarbon feedstock into gaseous components by applying heat under pressure in the presence of steam.

A gasifier differs from a combustor in that the amount of air or oxygen available inside the gasifier is carefully controlled so that only a relatively small portion of the fuel burns completely. This "partial oxidation" process provides the heat. Rather than burning, most of the carbon-containing feedstock is chemically broken apart by the gasifier's heat and pressure, setting into motion chemical reactions that produce "syngas." Syngas is primarily hydrogen and carbon monoxide, but can include other gaseous constituents; the composition of which can vary depending upon the conditions in the gasifier and the type of feedstock.

Minerals components in the fuel, which don't gasify like carbon-based constituents leave the gasifier either as an inert glass-like slag or in a form useful to marketable solid products. A small fraction of the mineral matter is blown out of the gasifier as fly ash and requires removal downstream.

Sulfur impurities in the feedstock are converted to hydrogen sulfide and carbonyl sulfide, from which sulfur can be easily extracted, typically as elemental sulfur or sulfuric acid, both valuable byproducts. Nitrogen oxides, another potential pollutant, are not formed in the oxygen-deficient (reducing) environment of the gasifier; instead, ammonia is created by nitrogen-hydrogen reactions. The ammonia can be easily stripped out of the gas stream.

In Integrated Gasification Combined-Cycle (IGCC) systems, the syngas is cleaned of its hydrogen sulfide, ammonia and particulate matter and is burned as fuel in a combustion turbine (much like natural gas is burned in a turbine). The combustion turbine drives an electric generator. Exhaust heat from the combustion turbine is recovered and used to boil water, creating steam for a steam turbine-generator.

The use of these two types of turbines - a combustion turbine and a steam turbine - in combination, known as a "combined cycle," is one reason why gasification-based power systems can achieve high power generation efficiencies. Currently, commercially available gasification-based systems can operate at around 40% efficiencies; in the future, some IGCC systems may be able to achieve efficiencies approaching 60% with the deployment of advanced high pressure solid oxide fuel cells. (A conventional coal-based boiler plant, by contrast, employs only a steam turbine-generator and is typically limited to 33-40% efficiencies.)

Higher efficiencies mean that less fuel is used to generate the rated power, resulting in better economics (which can mean lower costs to ratepayers) and the formation of fewer greenhouse gases (a 60%-efficient gasification power plant can cut the formation of carbon dioxide by 40% compared to a typical coal combustion plant).

All or part of the clean syngas can also be used in other ways:

As chemical "building blocks" to produce a broad range of higher-value liquid or gaseous fuels and chemicals (using processes well established in today's chemical industry);

As a fuel producer for highly efficient fuel cells or perhaps in the future, hydrogen turbines and fuel cell-turbine hybrid systems;

As a source of hydrogen that can be separated from the gas stream and used as a fuel (for example, in the hydrogen-powered Freedom Car initiative) or as a feedstock for refineries (which use the hydrogen to upgrade petroleum products).

Another advantage of gasification-based energy systems is that when oxygen is used in the gasifier (rather than air), the carbon dioxide produced by the process is in a concentrated gas stream, making it easier and less expensive to separate and capture. Once the carbon dioxide is captured, it can be sequestered - that is, prevented from escaping to the atmosphere, where it could otherwise potentially contribute to the "greenhouse effect."


http://www.fossil.energy.gov/programs/powersystems/gasification/index.html

[margotb822]

12. Very helpful, thanks!

[MUAD_DIB]

11. It's like Military Intelligence...

[Cirque du So-What]

13. An excellent ad from the Sierra Club

http://www.thisisreality.org/#/?p=facility

[XemaSab]

14. I know people who have worked on clean coal

It's as much of a myth as hydrogen cars or fusion: In short, it's something people are working on that hasn't been perfected yet.

[doc03]

16. Not "clean coal" but much cleaner than in the old days

I live in coal country and back in the 50s just about everyone heated with coal, now that was dirty. Back in the 60s nearly everyone switched to oil that was a big improvement. Today most people are using electric heat generated from coal. A power plant with the latest environmental systems is far cleaner than if you had thousands of individual homes using either coal or oil furnaces with absolutely no pollution controls. Back in the 50s snow turned gray in a few hours. I remember going on a field trip to the Carnegie Museum in Pittsburgh back in the 5th grade and you could barely see the other side of the street. In Weirton WV you could actually feel the particulates hitting your face when you walked down the street. The Ohio river was an open sewer back in those days and totally dead outside of carp and rats. Today the Ohio river is a great fishery.

[all.of.me]

17. But what about how clean coal itself actually is.

It is filthy! Ever looked around a coal-fired power plant? It is gross. I imagine it's toxic, too. It would seem to me that you can clean up the emissions, but can you clean up the coal? Mining, transporting, and letting a pile sit at a power plant seem pretty dirty to me.

[margotb822]

22. Have you ever seen the Bodies exhibit?

I saw it in Boston a few years back, and they had three sets of lungs: non-smoker, smoker, and coal miner. It was fascinating because the coal miner's lungs were black, but the coal made them sparkle. They were very different compared to the withered, crusty lungs of the smoker. Coal is filthy and when it's broken into those fine particles, it's near impossible to filter.

[all.of.me]

24. Ewwwwwww... no! Sounds gross, but very enlightening.

When I drive my kiddo to school in AZ, we go by a coal-fired plant on I-40. There is a huge pile of coal out there probably bigger than five super Wal Marts. When that wind is blowing, you can't tell me it's ok for the people and critters in the area! Thank God it's sparsely populated, but still......... it's in the air. Nasty, nasty, nasty.

[bananas]

19. I like this description of carbon capture

"Clean coal through carbon capture is fine if it can be made to work. But if you actually injected all of the CO2 produced in the United States (1.5 billion tonnes) the entire country would jack up in the air by 1mm/year. You don’t have to be a scientist to know that is not sustainable."
http://www.theclimategroup.org/news_and_events/stephen_pacala/

[Nihil]

20. Great. NOW you've done it ...

> But if you actually injected all of the CO2 produced in the United States
> (1.5 billion tonnes) the entire country would jack up in the air by 1mm/year.

How long before some bozo starts touting this as the solution to sea-level rise?

:spank:

[margotb822]

21. Well, we better get started then, since

the seas are rising faster!

[TheWraith]

23. It's all based around the principle of reducing a coal plants emissions. There's several ways.

The most widespread at this point is to install scrubbers and filters on the exhaust from the plant, to remove smog-causing particles and other harmful elements before it's released into the air. There's also things like coal gasification, which is more difficult but provides a correspondingly cleaner end result.

People call it a myth mostly because it's not really "clean," simply "cleaner." However, considering that the alternative is the continued use of regular coal, clean coal is an obviously more palatable alternative until the stuff can be replaced entirely. Some are afraid that if the public gets sold on clean coal, it'll mean no one wants to switch to anything else, which is why some people fight it. Of course, others fight it because it would cost the coal industry money to upgrade their plants.