Gasification – Clean Coal and Other Fuels

Gasification involves a set of chemical reactions that convert carbon-containing feedstock into synthetic gas. It uses only a small amount of oxygen which when combined with steam and put under intense pressure produces a gaseous mix of carbon monoxide and hydrogen. This synthetic gas can be burned directly or used to start the development of fertilizer, pure hydrogen, methane, or liquid transportation fuels. Gasification has existed for decades but the recent increased focus on alternative energy sources has reinvigorated interest in gasification.

Gasification Processes

There are three common forms of the gasification process:

• Coal Gasification: The most common form of gasification, coal gasification uses a gasifier instead of a boiler operating on a daily quantity of 16,000 tons of lignite. Operating in place of a boiler, the gasifier operates at significantly higher temperatures and pressures, 2,600 degrees F and 1,000 psi, causing the coal to experience different chemical reactions. The end products, carbon monoxide and hydrogen, are combusted cleanly in gas turbines which in turn, produces much cleaner electricity.
• Wood Gasification: Though coal gasification can generate electricity without the harmful toxins and carbon dioxide byproducts, it does requires nonrenewable fossil fuel and toxic waste producing mining operations. Wood gasification, referred to as biomass gasification, is made from organic materials and is therefore considered a renewable energy source. The process is similar to that described for coal gasification, but uses feedstock instead of coal. There are 4 categories of feedstock and various gasifier designs based on the choice of feedstock, which determines the relative proportions of compounds used in the process.
• Homemade Gasification: Gasification is entirely scalable, so a relatively small gasifier can be built to service relatively small areas, or in areas where an emergency backup may be required for very specific applications. Whether personally built or purchased from a manufacturer, homemade gasification systems, using a variety of fuels (e.g. seasoned wood, saw dust, and wood chips), can be used to heat houses, garages and other smaller buildings and/or structures.