08 March 2009

the biggest oxymoron


Adding to the list of 'healthy fast-food', 'good government', 'peacekeeping force' and... 'Microsoft works' there is the newest oxymoron: clean coal. Coal of course has been one of the earliest sources of energy and at one point it was known as 'black gold'. Nowadays it is being rebranded as 'clean coal'.

Clean coal is an umbrella term used to promote the use of coal as an energy source by emphasizing methods being developed to reduce its environmental impact. These efforts include chemically washing minerals and impurities from the coal, gasification, treating the flue gases with steam to remove sulfur dioxide, carbon capture and storage technologies. Major politicians and the coal industry use the term 'clean coal' to describe technologies designed to enhance both the efficiency and the environmental acceptability of coal extraction, preparation and use, with no specific quantitative limits on any emissions, particularly carbon dioxide.

Even if clean coal technologies can be developed and deployed at a commercial scale in power generation, they will do nothing to make the mining of coal a less polluting activity. As 25.5% of the world's electrical generation in 2004 was from coal-fired generation, reaching the carbon dioxide reduction targets of the Kyoto Protocol will require modifications to how coal is utilized. Carbon sequestration technology has yet to be tested on a large scale and may not be safe or successful. Sequestered CO2 may eventually 'leak' up through the ground, may lead to unexpected geological instability or may cause contamination of aquifers used for drinking water supplies.

The byproducts of coal combustion are considerably hazardous to the environment if not properly contained. Coal-fired power plants are the largest aggregate source of mercury: 50 tons per year come from coal power plants out of 150 tons emitted nationally in the USA and 5000 tons globally. There are forms of clean energy such as geothermal, biomass, solar, wind and hydroelectric and other renewable energy sources which are supported by many of the environmentalist groups and campaigns. Critics of the planned power plants assert that there is no such thing as 'clean coal' and that the plant will still release large amounts of pollutants compared to renewable energy sources such as wind power and solar power.

By this technology, emissions and wastes are not avoided, but are transferred from one waste stream to another. As coal-fired power plants work to create cleaner skies, they'll likely fill up landfills with millions more tons of potentially harmful ash. Chemicals are injected into plants' emissions to capture airborne pollutants. That, in turn, changes the composition of the ash and cuts its usefulness. It can't be used in cement, for example, because the interaction of the chemicals may keep the concrete from hardening.

That ash has to go somewhere - so it usually ends up in landfills, along with the rest of the unusable waste. Essentially, replacing an air problem with a land problem - a disposal problem. The chemicals added to clean up emissions - such as ammonia, lime and calcium hydroxide - make the ash worse, because they take toxins such as mercury out of the air but leave higher levels of it in the ash.

Coal works because it is cheap - but does it really? Ultimately there is no such thing as 'clean coal' and it is about time politicians stop pushing the agenda of coal industrialists. Give them all a new business plan - switch to renewable energy sources. If the so-called developed countries still continue to use outdated technologies, they cannot expect the less-privileged countries to give up the same cheap technology. Out with the old, says I. What says you?


Coen Brothers' TV advert for clean coal
video

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