isobutane to n-butane

Try Googling 'C4 Isomerisation Processes'!

Try C4 Isomerization and you will have slightly better luck on the n-butane to isobutane process.

There are several catalysts that can do this for you in a column type reactor bed. The separation and recycle is the key to cleaning up your n-butane stream. UOP has a process that works pretty good:

http://www.uop.com/refining/1041.html

As to the iso to normal butane process, the separation is via distillation. The distillation column is commonly called a deisobutanizer.

If you need help with the design, there are lots of chemical engineers out there willing to do the work (shameless plug).

Stephan

Converting iso to normal involves a patented process which consists essentially of contacting normal butane at temperatures less than 50 °C with a catalyst of fluoresulfuric acid and trifluoromethanesulfonic acid. I am not familiar with the specifics.