An alkyl is a functional group of an organic chemical that contains only carbon and hydrogen atoms, which are arranged in a chain.
They have general formula CnH2n+1
Examples include methyl CH3 (derived from methane) and butyl C2H5 (derived from butane). They are not found on their own but are found attached to other hydrocarbons.
Alkylation is a refining process in which an alkyl group replaces a hydrogen atom in an organic compound.
An alkylate is the product of an alkylation process.
The process of alkylation is for instance used in petroleum refining to produce high-octane gasoline, a process using hydrofluoric acid (HF) as a catalyst.
Fluoride - Methyl group