Butane Isomerization
Butane isomerization is the process of converting normal butane into isobutane. Normal butane and isobutane are NGLs that are naturally produced from processing natural gas and as a byproduct from crude oil refining. The supply of normal butane generally exceeds demand, while the demand for isobutane is normally greater than the supply.
Isobutane is used primarily by the petrochemical industry for the production of propylene oxide and is also used to produce additives for motor gasoline that increase octane and lower vapor pressure. These additives are combined with motor gasoline to meet the federal environmental standards for exhaust emissions from automobiles.
Enterprise has been in the isomerization business since 1981 and owns 3 butamer reactor units and 8 associated deisobutanizer units with a combined net production capacity of 116 MBPD of isobutane. These facilities are located at Enterprise's Mont Belvieu complex and comprise the largest commercial isomerization complex in the world.
Butane Isomerization Assets
| Facility | Ownership Interest at December 31, 2007 | Capacity (MBPD) |
| Mont Belvieu, TX Isom I |
100% |
36 |
| Isom II | 100% |
36 |
| Isom III | 100% |
44 |
| Total | 116 |


