Coal is an energy source that has been under quite a bit of scrutiny over the last decade or so. Being one of the dirtiest forms of energy, there has been a significant movement to either clean it up or do away with it entirely. Recognizing the need for change, the coal industry has invested significant funding into the research of clean coal that will allow the continued usage of coal as an energy source, but that will also significantly decrease the carbon footprint it leaves behind.
There are now a variety of methods used to literally make coal clean. The first method is known as coal washing. It is a type of preparation that removes minerals that are unwanted or unneeded in the coal before it is burned. They do this by first crushing the coal and then combining it with a liquid solution that separates the components that are no longer needed.
Web scrubbers are also used to create clean coal. This enables the coal plants to control the burn of the coal so that harmful gases are not omitted into the atmosphere, such as sulfur dioxide. That particular component is responsible for acid rain, so removing it dramatically improves the quality of an energy plant that is coal based as it relates to the eco-system.
Nitrogen Oxides are another component of coal that has created some significant issues over the years. Low-NOx burners dramatically decrease the release of nitrogen oxides that would normally be produced during the burning process due to a manipulation of the combustion process. This particular element was related to aggravating such conditions as asthma and controlling it obviously created a significant improvement in air quality in and around coal plants.
Another process actually eliminates the need for burning coal in any form. The IGCC (integrated gasification combined cycle), uses oxygen and steam (or pressurized hot air) to force a reaction separating carbon molecules. This process creates a syngas (combination of hydrogen and carbon monoxide) that is run through a cleaning process and then burned off to power the turbines that generate the electricity.
The one form of clean coal that looks to be the future of the industry uses a flue-gas separation process that totally removes carbon dioxide from the equation. This is pretty significant as carbon dioxide is a culprit of global warming and removing it entirely will have a significant impact on the entire eco-system. While much of this technology is fairly new, great strides are being made and it is only a matter of time before this becomes the norm instead of the exception.