About UCG
Underground coal gasification (UCG) is a proven technology that gasifies coal deep underground, unlocking the safe energy potential of an abundant natural resource. UCG-produced syngas is a bridge fuel that can help the nation economically and reliably transition from petroleum to more sustainable energy resources.
About Underground Coal Gasification
About Underground Coal Gasification
UCG converts deeply buried, unmineable coal “in-situ” (in position) into synthesis gas (syngas) that can be used for low-carbon energy production and petrochemical manufacturing. UCG avoids environmental, health and safety risks associated with conventional coal mining, handling, transport and waste by containing the process and most byproducts underground in the original coal seam. The gasification process takes place below impermeable rock layers isolated from freshwater aquifers. UCG-produced syngas can be used directly to generate electricity with gas turbines or converted into synthetic natural gas for local use and export. Syngas is also an excellent feedstock for producing clean-burning liquid fuels including gasoline, diesel and jet fuel as well as production of fertilizer, plastics and other petrochemical products.
With the Exergy UCG™ technology, coal is converted while still underground "in-situ" into multiple gas streams that are easily separated at the surface into useful and sequesterable components resulting in a total carbon footprint similar to natural gas. Additionally, the Exergy UCG process eliminates a wide range of emissions and requires no surface mining or ash disposal, turning an abundant, domestic natural resource into a clean, low-cost synthesis gas for climate-friendly, economical energy production, chemicals and other products.
Responsible UCG projects require careful site selection and evaluation to identify deep coal seams that are typically at least 650 feet below the surface. The UCG process is controlled from the surface by managing the injection of the oxygen. Operators can quickly halt the process at any time by cutting the oxygen supply or flooding the well with water. Natural water influx will quench the reactions, eliminating any potential for unwanted coal-seam fires. Some of the coal is left in place to prevent subsidence (unintentional settling).
Why consider UCG?
Commercial-scale UCG projects have been used to gasify and convert coal for more than 50 years. There have been more than 50 test and commercial UCG projects worldwide, including in the U.S. Numerous commercial operations are currently in various stages of design, development, scale-up or operation. Recent investment and scientific study have led to a better scientific understanding of the UCG process.
Commercial-scale carbon capture technologies are mature and have been successfully used for years to remove carbon dioxide from syngas produced at surface coal-gasification plants. UCG lends itself easily to carbon management. The UCG process also produces syngas at temperatures, pressures and CO2 concentrations that enable relatively simple, low-cost carbon removal, prior to use. The syngas is then burned to create clean energy with a carbon footprint similar to that of natural gas and far below that of coal mining and combustion.
UCG with carbon management is clean, economical and safe. It has a small carbon and environmental footprint. UCG can become a bridge technology that will help our nation move toward domestically produced, sustainable energy resources and away from its dependence on imported oil.