Isomerization of butane

A process for liquid-phase isomerization of normal butane to isobutane which consists essentially of contacting normal butane at temperature less than 50.degree. C. for a period of time less than 30 minutes with a catalyst composition consisting essentially of 95 to 99 weight percent fluorosulfuric acid and 1 to 5 weight percent sulfuric acid, and thereafter recovering isobutane.

A prpocess for liquid-phase isomerization of normal butane to isobutane which consists essentially of contacting butane charge stock and a C.sub.2 -C.sub.10 olefin added to the butane charge stock in amouts ranging from about 0.05 to 10% by weight based on the charge stock for the purpose of providing an equilibrium concentration of cations during the isomerization reaction and thereby minimizing decreased catalyst activity at a temperature from 10.degree. C. to 30.degree. C. for a period of time ranging from 30 second to 5 minutes with a catlyst composition consisting essentially of 95 to 99 wt. % fluorosulfuric acid and 1 to 5 wt. % of protic co-acid selected from the group consisting of hydrogen fluoride, sulfuric acid, trifluiormethyanesulfonic acid, and mixtures thereof, and thereafter rcovering isobutane.

A continuous process for liquid-phase isomeriation of normal butane to isobutane which consists essentially of contacting butane charge stock and a C.sub.2 -C.sub.10 olefin added to the butane charge stock in amounts ranging from about 0.05 to 10% by weight based on the charge stock for the purpose of providing an equilibrium concentration of cations during the isomerization reaction and thereby minimizing decreased catalyst activity at temperature less than 50.degree. C. for a period of time less than 30 minutes with a catalyst composition consisiting essentially of 95 to 99 wt. % fluoresulfuric acid and 1 to 5 wt. % of a protic co-acid selected from the group consisting of hydrogen fluoride, sulfuric acid, trifluoromethanesulfonic acid, and mixtures thereof, and thereafter recovering isobutane.