brain drain. brain drain. LINK / CITE ADD TO WORD LIST. noun. The definition of brain drain refers to a situation where all or the majority of intelligent, skilled or capable resources within a given field or geographic region leave the area because of various factors including lack of high paying jobs.
Alkylation is an important source for octane in gasoline. Source: Occupational Safety and Health Administration. Alkylation (al-kuh-ley-shun) is a secondary refinery unit operation that many refineries in the United States have because it adds high octane hydrocarbons to motor and aviation gasoline. High octane hydrocarbons are needed to help prevent autoignition of gasoline (knocking) in an engine and to meet recommended engine octane ratings.
In an oil refinery it is referred to as a sulfuric acid alkylation unit (SAAU) or a hydrofluoric alkylation unit, (HFAU). Refinery workers may simply refer to it as the alky or alky unit. The catalyst protonates the alkenes (propene, butene) to produce reactive carbocations, which alkylate isobutane.