A dilithium processing unit was an important component of some warp propulsion systems.

In 2256, Voq needed a dilithium processing unit to complete repairs on the Sarcophagus. Reluctantly, he agreed to L'Rell's suggestion to salvage one from the abandoned USS Shenzhou. The processing unit needed to be removed delicately, as it was coated in dilithium crystal residue. (DIS: "The Butcher's Knife Cares Not for the Lamb's Cry")