Isomerization in a variety of process configurations alters the arrangement of atoms to convert normal butane into isobutane, and normal pentane and hexane into highoctane gasoline components. Isomerization is similar to catalytic reforming in that the hydrocarbon molecules are rearranged, though isomerization only converts normal paraffins to isoparaffins.
Near the end of the process, reactor effluent is cooled and separated into the liquid product isomerate and a recycle hydrogen-gas stream. Isomerate is caustic-washed and waterwashed, acid stripped, and stabilized before going to storage. Stabilizer bottoms and wash tanks require level monitoring.