Can burning coal and garbage really be 100% clean?

[fuzzybabybunny]

I have a friend who is really big on garbage burning. In areas where the landmass is too low and/or population is too high, trash burning can be made to be 100% clean. At high enough temperatures everything burns away and it's clean, and it is a self-perpetuating fire due to the waste being the fuel?

Is this the same as clean coal?

 

[Oil]

Wait what

 

[D1gger]

Short answer is no, but they are getting closer and closer to clean enough to be practical.

http://www.scientificamerican.com/article.cfm?id=does-burning-garbage-to-produce-energy-make-sense

 

[lxskllr]

It can be burned at very high efficiency, but when you're burning hundreds of thousands of tons of stuff, you're getting a shitload of pollution in the air even at 99% efficiency.

 

[Mark R]

Clean burning technologies are quite well advanced.

High temperature combustion with electric arc pyrolysis, electrostatic precipitation and selective catalytic reduction and heavy metal filtration will remove essentially all relevant toxins from the flue gases.

This sort of technology is pretty standard on modern refuse incinerators - the ultra-high temperature pyrolysis unit will destroy the dioxins and other toxins produced from combustion of plastics; the precipitators will remove fly ash debris, the urea reduction will remove the nitrogen oxides (often leaving lower levels of these smog forming agents than were found in the incoming air) and the heavy metal filters will trap mercury and other volatile metals (e.g. from CFLs or similar items going into the incineration stream).

This type of technology is expensive though. We have one here, and even though it has generators and sells the electricity, and instead of cooling towers it sells hot-water to nearby the university and downtown office buildings, it barely breaks even. It only stays in business because the local govt won't allow landfill.

 

[drinkmorejava]

that guy ^^

 

[Dice144]

Better than having landfills take over the free space!

 

[PowerEngineer]

It seems to me that the answer depends on your definition of "clean". As Mark_R describes, there have been significant improvements made in our ability to capture impurities and to force buring toward complete combustion. But combustion of any carbon-containing fuel leaves you with carbon dioxide as an end product. Is carbon dioxide "clean"?

There have been proposals made to somehow extract carbon from fossil fuels (like coal) before burning (i.e. just burn the hydrogen) and to capture and sequester the carbon dioxide after burning. I have a hard time seeing how this can be made practical.

 

[benzylic]

Clean coal really isnt clean, its just cleaner.

 

[qliveur]

LOL @ "burning coal".

 

[dud]

Can you imagine all the toxins released by burning garbage ...

No, its not "clean".

 

[Anonemous]

Still stuck in China?

 

[KeithP]

Can you imagine all the toxins released by burning garbage ...

No, its not "clean".

Imagination is nice but I think the thread is going in the direction of facts.

-KeithP

 

[MonKENy]

I have a friend who is really big on garbage burning. In areas where the landmass is too low and/or population is too high, trash burning can be made to be 100% clean. At high enough temperatures everything burns away and it's clean, and it is a self-perpetuating fire due to the waste being the fuel?

Is this the same as clean coal?

the big question is it in his backyard or in a high eff furnace?

 

[Imp]

Getting ideas from the locals in China?

 

[Anonemous]

Getting ideas from the locals in China?

http://www.usnews.com/news/world/articles/2013/01/13/air-pollution-in-beijing-goes-off-the-index

I'll just leave this here.

 

[fuzzybabybunny]

Like KeithP says, I don't think most in here know what's going on.

The situation was told to me by an American electrical and mechanical engineer that I met while over here. At high enough temperatures, everything gets burnt off.

I actually visited a Chinese coal and garbage burning plant. I could not smell anything off when I was touring the plant's grounds, but that in itself doesn't say much.

But if the results are really:

Garbage is disposed of, permanently.
There is little or no pollution.
Power is generated.

Even if economically it only breaks even or needs government to prop it up, it's still a hell of a lot better than burying our garbage in the ground, where you'll find 60-year-old hot dogs that still haven't decomposed due to the lack of oxygen down there. Not to mention I don't think landfills generate any kind of income - they're all just a "necessary" cost for the community.

 

[fuzzybabybunny]

http://www.usnews.com/news/world/articles/2013/01/13/air-pollution-in-beijing-goes-off-the-index

I'll just leave this here.

I'm in Beijing as I'm typing this. It's horrible. But if the facts and physics are right, part of the problem is that Beijing doesn't have *enough* clean garbage incinerators.

 

[fuzzybabybunny]

Clean burning technologies are quite well advanced.

High temperature combustion with electric arc pyrolysis, electrostatic precipitation and selective catalytic reduction and heavy metal filtration will remove essentially all relevant toxins from the flue gases.

This sort of technology is pretty standard on modern refuse incinerators - the ultra-high temperature pyrolysis unit will destroy the dioxins and other toxins produced from combustion of plastics; the precipitators will remove fly ash debris, the urea reduction will remove the nitrogen oxides (often leaving lower levels of these smog forming agents than were found in the incoming air) and the heavy metal filters will trap mercury and other volatile metals (e.g. from CFLs or similar items going into the incineration stream).

This type of technology is expensive though. We have one here, and even though it has generators and sells the electricity, and instead of cooling towers it sells hot-water to nearby the university and downtown office buildings, it barely breaks even. It only stays in business because the local govt won't allow landfill.

But it's gotta be better in the long run than a landfill, right? Landfills don't generate any useful resources, do they?

Larger initial expenditure than landfills, but better in the long run. That's the issue with modern incinerators?

 

[TurtleCrusher]

There's no getting around this. CO2 is produced.

 

[Thebobo]

But it's gotta be better in the long run than a landfill, right? Landfills don't generate any useful resources, do they?

Larger initial expenditure than landfills, but better in the long run. That's the issue with modern incinerators?

Landfills generate methane which is often used to generate power, no sure at what efficiency.

Also landfills produce open land and step sided hills where I can fly my RC sailplanes

 

[oynaz]

There's no getting around this. CO2 is produced.

Burning garbage is CO2 neutral.

Garbage burning has been going on for some time in Denmark. The pollution problems are not any bigger than when using coal or oil (coal is far worse, actually).
The incenerators here are quite modern, though.

 

[rcpratt]

There's no getting around this. CO2 is produced.

There's a lot more to energy pollution than that.

 

[bignateyk]

Can you imagine all the toxins released by burning garbage ...

No, its not "clean".

Well that depends. If you're talking about your average redneck burning trash in a barrel in his backyard, then yes, it's pretty much dumping toxins into the air.

If you're talking about highly sophisticated large scale burning operations, then no, they're actually quite clean.

 

[lxskllr]

If you're talking about highly sophisticated large scale burning operations, then no, they're actually quite clean.

Quite clean isn't good enough when dealing with large volumes. I don't follow the tech, nor am I in the industry, but the incinerator in Baltimore produced an enormous amount of crap from it's stacks. You can't see it, but it comes out non the less. Invisible pollution isn't any better than visible. That's a couple decades old now, so maybe they're better now, but I won't believe absolute cleanliness until I see the numbers.

None of that is to say it isn't a good idea. Incineration is probably one of the best ideas for getting rid of crap, but whitewashing it's detriments isn't productive.