What is the difference between UCG and CSG?
The two processes and their products are vastly different. While UCG and CSG both produce gas, the product gases are very different and applied to different end uses.
UCG and CSG: Differences
| Underground Coal Gasification (UCG) | Coal Seam Gas (CSG) | |
| Energy Source | Coal | Gas in Coal |
| Process description | Gasification, in the presence of pressure from groundwater in the coal, generates syngas that is produced through wells | Extraction of water in the coal to relieve pressure allows naturally occurring methane gas to flow out of the well |
| Product | Processed gas of primarily hydrogen, carbon monoxide and methane | Methane |
| Energy recovery | About 85% of energy in the coal | About 5% of energy in the coal |
| Delivery | Wells and pipelines | Wells and pipelines |
| Final product | Liquid fuel, chemical feedstock, petrochemicals and plastics, power generation | Liquefied natural gas, liquid fuel, power generation. |
| Footprint | For the same energy value, about half the area of an open cut coal mine and 20 times less than CSG | Variable |
| Land disturbance | Minimal | Minimal, but over large land area |
| Waste water | Relatively small quantities of water containing organic compounds (oils) | Large quantities of water containing inorganic compounds (salts) |
| Persistence of waste | Readily recoverable as a useable by-product and / or degradable | Persistent in the environment |
| Water treatment process produces | Clean water and CO2 | Clean water and lower volumes of hyper-saline water (brine) |
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.
