The doonium refinery was a large Imperial installation built on the planet Ryloth in 19 BBY, and was the first of many planned sites. Massive pipelines ran into the the depths of a large mountain and extracted doonium back into the installation to be refined. The bulk of the refinery's workforce was made up of the native Twi'lek population. The refinery was defended by several turbolasers and a garrison of clone stormtroopers.
- Star Wars: Dawn of Rebellion: The Visual Guide