Clean Coal Technologies

When it comes to coal and environment, the issue is more of availability and affordability, and that is what keeps coal from being stricken out of the energy sources list in our times. Generally considered as a big threat to the environment, coal is known to release large quantities of carbon dioxide in the air, adding to the problem of greenhouse effect (global warming), when it is converted to electric power. But coal power generation also gives out other harmful emanations like oxides of sulfur and nitrogen.

Still, coal is, so far, the cheapest solution for the problem of generating electric power on a large scale. In the US alone, it currently accounts for over half of the total amount of electric power generation. Wind power, on the other hand, is less than one per cent of the total power generated in the US. In developing countries, replacing coal with alternative sources of power is, at this time, next to impossible due to technological and cost issues. For environmental friendly approaches to power generation, there is hardly any other choice than focusing on clean coal technology.

Multiple technologies have been developed for cutting the noxious emissions of coal when it is burnt for power generation. Coal washing, for example, takes away the mineral contaminations from the coal before it’s burnt to generate power; wet scrubbers have been invented to seizing sulfur dioxide from the coal; and Low-Nox burners can cut the nitrogen oxides that are released upon burning coal. There is also the gasification of coal, which avoids the fuel’s burning altogether, using hot air and steam under pressure to capture the carbon from the coal and reducing its carbon emissions. The most looked upon clean coal technology, however, is the Carbon Capture and Storage (CCS), which seizes the carbon emissions from coal power plants (instead of the coal only).

A number of technologies have been developed for this purpose too: flue-gas separation, oxy-fuel combustion, and pre-combustion capture, to name a few. The captured carbon dioxide is then injected either into the earth or in the ocean. In the earth, it can be given over to depleted fossil fuel reservoirs – something that actually helps in their enhanced recovery. In case of oceans, environmentalists have strong concerns about its safety to the marine habitats as it acidifies ocean water.

The problem of affordability remains with all the clean coal technologies; in fact, the cleaner the technology, the higher the costs involved. In Germany, technological advance has led to a 20% rise in the efficiency of clean coal power plants as compared with the previous ones. A study conducted in Hamburg foresees that by 2050, the CCS efficiency will rise to include 100 per cent of the clean coal plants in Germany, cutting CO2 emissions by more than 80 per cent of the existing levels. In the United Kingdom, a 2% reduction in greenhouse gas emissions was recorded in 2007 as compared with those in 2006; the country now expecting a decrease of around 20% by 2010. However, some analysts have attributed this improvement to the rise in coal prices instead of technological advance.

As Bjorn Lomborg, of the Copenhagen Consensus Center, put it in his article Climate Change Posers, the end of fossil fuels’ stronghold in power generation will only end when we get cheaper green alternatives. Till then, minimizing our needs and checking our consumption will remain the primary clean coal strategies.

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