Octane Enhancement

Enterprise owns a state of the art gasoline additive production facility that has been modified to produce isooctane, a motor gasoline octane enhancement additive derived from isobutane. This facility is located in the Company's Mont Belvieu complex and produces isooctane and isobutylene using feedstocks of high-purity isobutane, which is supplied using production from our isomerization units.

Prior to mid-2005, the facility produced methyl tertiary butyl ether ("MTBE"), the production of which was primarily driven by oxygenated fuel programs enacted under the federal Clean Air Act Amendments of 1990. In recent years MTBE has been detected in water supplies, and as a result of environmental concerns, several states have enacted legislation to ban or significantly limit the use of MTBE in motor gasoline within their jurisdictions. Federal legislation has also been drafted to ban MTBE and replace it with renewable fuels such as ethanol. In light of these developments, we modified the facility to produce isooctane and isobutylene. Depending on the outcome of various factors, the facility may be further modified in the future to produce alkylate, another motor gasoline additive.