Alkylate
Alkylate is the primary product of the alkylation unit, which converts light olefins (such as butylene) into a high-quality gasoline blendstock by reacting it with isobutane.
There are several types of alkylate, based on the different olefins used to produce it. The most common, and desirable is C4 alkylate, which is produced from alkylating (joining) butylene with isobutane. However, alkylate can also be made from propylene and isobutane, or pentene and isobutane.
C4 alkylate is preferred because it has the most desirable properties for gasoline blending, high octane and low vapor pressure. All alkylates also benefit from containing no aromatics components.
Properties
Alkylate is considered a premium gasoline blend stock because of it combination of properties:
Low sulfur content - Alkylate has no sulfur
Low aromatics content - Alkylate contains no aromatics
Low vapor pressure - Alkylate has a low vapor pressure.
C4 alkylate has an RVP of 2.6psi.
C3 alkyate has an RVP of 3.8psi.
C5 alkylate has an RVP of 4.0psi.
High octane - Alkylate has medium to high octane depending on the type.
C4 alkylate has a RON of 94-98 (MON of 92-94).