Coal is a vital fuel in most parts of the world. Burning coal without adding to global carbon dioxide levels is a major technological challenge which is being addressed. The most promising "clean coal" technology involves using the coal to make hydrogen from water, then burying the resultant carbon dioxide by-product and burning the hydrogen. The greatest challenge is bringing the cost of this down sufficiently for "clean coal" to compete with nuclear power on the basis of near-zero emissions for base-load power. Coal is an extremely important fuel and will remain so. Some 23% of primary energy needs are met by coal and 39% of electricity is generated from coal. About 70% of world steel production depends on coal feedstock. Coal is the world's most abundant and widely distributed fossil fuel source. The International Energy Agency expects a 43% increase in its use from 2000 to 2020. Here is an information that might be useful: lincenergy.us
With "Clean Coal" dont they just pump the emissions from the power plant into a big hole in the ground. Don't get me wrong there is a place for coal and nuclear energy, but to soften it up by saying its clean to give off the impression that there isn't any harmful waste is misleading. More renewable energy sources are the future, obviously in places that have less hours of sunlight or less consistent wind would need supplemented by coal, nat. gas, and nuclear energy.
The observed rate of increase of atmospheric CO2 shows that we are producing an excess of more than one thousand cubic miles (roughly ten billion tonnes) of the gas every year. It might be physically impossible, never mind economical, to capture and permanently bury anything like that much material. On the flip side, if we continue using coal at today's rate the world will run out in roughly a hundred years. We need to start replacing it and not waste money, time and political will trying to patch it up.
Richard and Sage have stolen my thunder,, Clean coal IS an oxymoron! And the shear cubic volume of carbon that needs to be sequestered from coal fired plants is greater than the volume of Lake Erie,,,,each and every year. Where are you going to get that volume every year in secure geology? Until we find a different 'use' for the carbon it is a non starter. This doesn't diminish the present importance of coal,, it just points out the scope of the problems that we have to solve,,,,sooner or later. Icarus
Efficiency and conservation are the most cost effective sources of energy. As said above, "clean coal" is an cruel oxymoron. We need a national "Interstate Highway" effort on transportation - walking & bicycle routes, electric & high speed rail. Coal is stored "old sunlight," that we need to keep sequestered, not transferred to the atmosphere. While coal is abundant, we cannot afford to choose coal.
One interesting aspect of shoving coal into the ground is that it can react with in situ materials to form calcite, the basic component of coral and the like (actually, these creatures create Aragonite, which has the same chemical composition as calcite, but a different crystalline structure). Peridotite can also react with CO2 to create stable, solid compounds. Unfortunately, peridotite isn't very common at the earth's surface (though this is the case in Oman). So it's a little more complex an issue, but making coal clean is probably a pretty expensive endeavour and there are probably better alternatives.
Among the recent proliferation of scientific journals devoted to energy, carbon and climate topics, I would like to mention Energy & Environmental Science Articles Not because it is necessarily the best, but their articles can be accessed freely. A few on their 'in press' page (linked above) deal with this very topic. If there is interest at PC I could compile a list of open-access journals that publish in these areas.
Hi. Nice sharing about coal technologies. Well we have to use our fossil fuels in a limited way, so that they will not get exhausted. These fuels pollute our environment also, We have to keep our environment clean, so that every one can live a healthy and good life.
I have a silly question, When we sequester carbon as carbon dioxide, what happens to replace the oxygen sequestered with it or is that not significant? If it isn't significant to sequester 2 oxygen atoms is it less significant to sequester 1 carbon atom? Yes I know we are not talking about 1 or 2 atoms but you get my drift I'm sure. As far as I know when we dig up coal or oil there isn't all that much oxygen in it. Correct me if I'm wrong.
You are correct. The next question of could massive sequestering of carbon dioxide have an indirect effect is a good one. It obviously depends on the scales involved. Using history as a guide, the initial claims will be the effect is too small to matter with the actual result being vastly more significant.
It sorta depends because the CO2 may react with the country rock to produce minerals like calcite, which would free up the O2 (of course, it's still stuffed way down in the ground). CO2 interactions with peridotite probably end up the same way. It's obviously a much more complicated thing than it's made out to be. In the end I think we won't see a lot of CCS because it's just going to prove to be too expensive to make it competitive with other energy technologies.
