How Coal Gasification Power Plants Work

[madokie]

The heart of gasification-based systems 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, carbon monoxide and other gaseous constituents, the proportions of which can vary depending upon the conditions in the gasifier and the type of feedstock.

Minerals in the fuel (i.e., the rocks, dirt and other impurities which don't gasify like carbon-based constituents) separate and leave the bottom of the gasifier either as an inert glass-like slag or other marketable solid products. Only 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.

http://www.fe.doe.gov/programs/powersystems/gasification/howgasificationworks.html

[sam sarrha]

1. you forgot about 'Mountain Topping' in the Ozarks..Google:Mountain topping

[madokie]

2. I guess I shouldn't bring up gasification as an alternative to burning

:shrug:

[NNadir]

3. What do you suppose the market for sulfuric acid is?

If it's so damn valuable, why are millions of metric tons dumped in the atmosphere each year?

If sulfuric acid is so "easily" extractable from waste gases, why is it not "easily" accomplished already?

Where are the carbon dioxide waste dumps? Do you think it is acceptable for the earth's atmosphere to be such a dump?

[sam sarrha]

4. ELECTRIC CAR BATTERIES

[NNadir]

6. Any idea what proportion of the world's sulfuric acid goes into car batteries?

I guess you don't get it.

[XemaSab]

5. You can get IGCC with CO2 sequestration

Right now at work the big argument is using lake beds in the desert as sites for solar thermal. :P

[NNadir]

7. You cannot get IGCC with CO2 sequestration.

Not off the shelf.

No carbon dioxide dump capable of addressing 1 day's worth of the world's carbon dioxide output which is 74,000,000 tons per day.

http://www.eia.doe.gov/pub/international/iealf/tableh1co2.xls

The largest sequestration facility in the world, the Sleipner facility, which merely strips carbon dioxide from natural gas already under the sea, sequesters about a million tons a year, and three percent of that leaks out each year.

Where is there one, just one,.
IGCC plant on the face of this planet that sequesters all of its carbon? It's all just talk.

Coal is an unacceptably dangerous fuel and should be banned. Nobody knows what to do with the waste.