Penex

The Penex process is a continuous catalytic process used in the refining of crude oil. It isomerizes light straight run naphtha (C5/C6) into higher-octane, branched C5/C6 molecules. It was first used commercially in 1958.
The Penex process uses fixed-bed catalysts containing chlorides. A single pass of feedstock with an octane rating of 50-60 through such a bed typically produces an end product rated at 82-86. If the feedstock is subsequently passed through a DIH (deisohexanizer) column, the end product typically has an octane rating of 87-90.5. If the feedstock is subsequently passed through a Molex-technology column, the end product typically has an octane rating of 88-91. If the feedstock is first passed through a DIP (deisopentanizer) column to remove iso-pentanes, then through the Penex bed, and subsequently through the DIH column, the end product typically has an octane rating of 91-93.
The Penex Process is licensed by the UOP corporation and currently utilized at more than 120 units at petroleum refineries and natural gas liquids plants throughout the world.