The key difference between UCG and CSG relates to the role that water plays in the process. UCG requires that water remains in the coal and adjacent to the underground environment to provide the hydrostatic pressure needed for containment of the process. A relatively small portion of the water takes part in the reaction to produce Syngas.
Conversely, CSG requires that most of the water be drained from the coal in order to relieve the pressure to produce methane. CSG produces large volumes of saline wastewater. Salt is persistent in the environment and cannot be broken down. UCG produces lower volumes of water, containing organic compounds that are readily degradable and can be easily treated using existing, and commercially available technologies.
Did you know?
- CG means coal is accessed underground, without the need for a surface mine.
- New technology, such as directional drilling, and demand for energy, are driving expansion in the Syngas industry.