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[Don Bowen <don.bowen AT earthlink.net>]

At 5/31/2005, you wrote:
> The reason I'm calling them dirty coal plants is because, according to the
> SF Chronicle lead story, if it's credible, they could make ones that turn
> the exhaust into a gas that have virtually no particulate emissions. I
> wonder is that coal gas, a useful fuel I believe?

Coal gas is an entirely different process.  Coal is heated to drive off the 
gasses then those gasses are captured, very similar to generating wood 
gas.  Most of the gas is hydrogen with some CO and CO2 mixed in.  In many 
areas this is called "town gas" because the first city lighting in the late 
1700s was with coal gas.   The first IC engines in the early 1800s used 
coal gas.

The by products are coke and some nasty tars.  Coke is used for heating and 
the tars gave rise to the German chemical and munitions industries in the 
1800s.

> Or if it's a slight of
> hand like the electric car where there's no emissions there but emissions as
> usual somewhere else?

Scrubber technologies are expensive and significantly reduce power plant 
efficiency.  There are some raw materials that can be derived from exhaust 
gasses but they are very expensive when compared to normal extraction 
technologies.  It is somewhat of a declining returns problem.  To make up 
for the power lost in a scrubber you have to increase the coal consumption 
which needs more scrubbers which require more energy.......  I have a 
friend who wrote a text book on scrubbers.  As has been said many times but 
almost completely ignored by politicians and therefore the 
populace,  "there ain't no free lunch."


Don Bowen                          Awl Knotted Up

My travel journal
http://www.braingarage.com/Dons/Travels/journal/Journal.html

My present location is the star on the map in the link below
http://www.mapquest.com/maps/map.adp?latlongtype=decimal&latitude=33.506083&longitude=-117.099019