CITGO Petroleum has announced a $310m investment to upgrade its Lake Charles Refinery in south-west Louisiana, US. The company will implement the Depentanizer Project to increase the refinery's naphtha upgrading capabilities by converting lower-value streams into components for gasoline blending. The project is scheduled for completion and operational start-up in 2029, and is expected to improve refinery operational flexibility and strengthen CITGO's capacity to supply dependable transportation fuels to meet ongoing US demand.