Tuesday, May 1, 2018

                   WHAT  COLOR  IS  YOUR  CARBON  BLACK ?

 An  exchange  on the difference between fossil hydrogen and  fossil carbon at Rabbet Run

Blogger Ken Fabian said...
Anything to do with CCS has to be treated with suspicion. 2.8 tons of CO2 for every ton of black coal burned is the fundamental arithmetic that can't be gotten around; lots more waste output by weight than input and requiring it's own specialised infrastructure.

But the post is about carbon pricing. I think it needs to apply to something nearer the centre of the problem, to actual emissions, to have real significance and absolutely not give tax benefits to enhancing fossil fuel recovery. 
28/4/18 7:46 PM
Blogger Russell Seitz said...
Ken needs to adjust his 'fundamental arithmetic.'

"Black coal" is not the same thing as carbon, in theory or energetic practice , because its composition varies so greatly. Some deposits yield solid fossil fuel with hydrogen to carbon ratios approaching those of liquid benzene or acetylene gas, and the CO2 per Kg burned varies in proportion.

It is mildly scandalous that carbon mitigators ignore what policies aimed at fuel chemistry mitigation might accomplish - favoring high hydrogen coals over those closer to anthracite could cut US CO2 emissions as much as instantly jumping to cars hat get 55mpg- it adds up to half a wedge. 

Russell, if I was treating high quality black coal as the same as pure carbon it would be closer to 3.6 tons of CO2. Best quality black coal makes 2.86 times it's weight in CO2. Yes, lower quality coal makes less - by weight of coal burned; but you burn more of it to make the same amount of energy so the total burden of CO2 for sequestration is not less. Which would be your point that shifting to black coal would reduce emissions. Just not by much, and nowhere near the emissions reductions we need to be making. Also, like any significant changes to our energy mix, there is no way to simply shift to high quality black coal on any near term time scale.
We get ads all the time on free to air TV (from Minerals Council of Australia) urging Australians to support new HELE coal plants. HELE is a misleading naming of high emissions coal plants as "high efficiency, low emissions". It may be higher efficiency than other coal plants but in climate terms it is - like gas - undisputedly high emissions, and a shift to them will entrench too high emissions for the lifetime of those plants.
So I don't think my arithmetic is in error.

Wrong  Ken-   you have to correct for  the atomic weight differential between C and H.

 Do so and you will find plenty of high volatile bitumenous deposits  offering substantial improvement in  energy  per pound at constant carbon content, with proportionate reductions both in CO2 per KWH when burned, and the amount of CO2 that needs sequestering - here's a table showing   a  16 % difference in carbon content  at constant energy density between Pennsylvania anthracite and Maryland bitumenous , and a whopping 35% relative to high volatile Ohio bitumenous coal: