Posted by
Aaron McLucas on Monday, May 26, 2008 11:05:05 AM
Some countries have no problem with turning to clean coal as a viable alternative to clean up their energy sources. In Austalia, some are upset that the country is not converting to it fast enough. It's the opposite here in the United States. The
U.S. government has offered that as a inexpensive way, along with other renewable energies, of reducing our carbon output that will give us short term results without costing the taxpayer billions of dollars to produce. Notice the first paragraph of the article:
Possibly offsetting criticism, the Bush administration wants to spend $2 billion on research into so-called clean coal technology aimed at reducing dirty emissions from coal-burning power plants.
- Coal cleaning by 'washing' has been standard practice in developed countries for some time. It reduces emissions of ash and sulfur dioxide when the coal is burned.
- Electrostatic precipitators and fabric filters can remove 99% of the fly ash from the flue gases - these technologies are in widespread use.
- Flue gas desulfurisation reduces the output of sulfur dioxide to the atmosphere by up to 97%, the task depending on the level of sulfur in the coal and the extent of the reduction. It is widely used where needed in developed countries.
- Low-NOx burners allow coal-fired plants to reduce nitrogen oxide emissions by up to 40%. Coupled with re-burning techniques NOx can be reduced 70% and selective catalytic reduction can clean up 90% of NOx emissions.
- Increased efficiency of plant - up to 45% thermal efficiency now (and 50% expected in future) means that newer plants create less emissions per kWh than older ones.
- Advanced technologies such as Integrated Gasification Combined Cycle (IGCC) and Pressurised Fluidised Bed Combustion (PFBC) will enable higher thermal efficiencies still - up to 50% in the future.
- Ultra-clean coal from new processing technologies which reduce ash below 0.25% and sulfur to very low levels mean that pulverised coal might be fed directly into gas turbines with combined cycle and burned at high thermal efficiency.
- Gasification, including underground gasification in situ, uses steam and oxygen to turn the coal into carbon monoxide and hydrogen.
- Sequestration refers to disposal of liquid carbon dioxide, once captured, into deep geological strata.
Coal is carbon heavy, but here is why you can't simply stop using it:
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.
Untill we can get other sources of renewables on line and at an affordable rate, coal will be with us for quite a while.