Does alkylation increase octane number?
Alkylation is an important source for octane in gasoline 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.
What is alkylation in petroleum refining?
alkylation, in petroleum refining, chemical process in which light, gaseous hydrocarbons are combined to produce high-octane components of gasoline. The light hydrocarbons consist of olefins such as propylene and butylene and isoparaffins such as isobutane.
Which catalyst is used in alkylation?
Alkylation is defined broadly as combining an olefin with an aromatic or a paraffin hydrocarbon using a catalyst—the most common catalyst is sulfuric acid.
What are two alkylation processes?
The product is called alkylate and is a premium gasoline blending stock because it has high octane numbers and a low sensitivity. There are two basic processes, one using concentrated hydrofluoric acid (Fig. 15) as the catalyst and the other using concentrated sulfuric acid.
What is alkylate in gasoline?
Alkylate is a gasoline blending stock that is produced by the acid-catalyzed reactions of olefins with normal hydrocarbons to yield higher boiling, and higher octane, iso-alkanes (Leffler, 2000).
What is the difference between alkylation and polymerization?
The difference between alkylation and polymerization is that we use just olefins in polymerization. No isobutane here. So we use three to four carbon atom olefins– typically again come from FCC process– combine them using a milder acid as a catalyst this time– so phosphoric acid.
What is the octane of alkylate?
The most important alkylate blending qualities in this respect are its high octane rating (94) and low RVP (4.0 pounds per square inch). Alkylate also has a very low sulfur content. These qualities make alkylate particularly attractive for blending today’s clean burning quality gasoline.
What is reformate gas?
11.2. Reformate is a gasoline blending stock that is produced by the catalytic reforming, a refining process in which mixed-catalysts and hydrogen promote the rearrangement of lower octane naphthenes into higher octane compounds without a significant reduction in carbon number (Leffler, 2000).
What is FCC gasoline?
FCC gasoline is the primary product of the FCC unit. FCC gasoline has approximately the properties required for finished gasoline (octane and vapor pressure). It is typically one of the larger components in the gasoline blend pool.
What is the major drawback of the alkylation process?
Alkylation units have two primary process hazards: 1) The unit process large volumes of light hydrocarbons which are highly flammable and potentially explosive. 2) The acid catalyst is corrosive and toxic.
What is high octane reformate?
Reforming is an oil refining operation that produces reformate, a high-octane gasoline blending component. Reformate is one of several blending components in finished gasoline. EIA expects gasoline production to increase during the summer driving season.
What is the octane rating of an alkylate?
Alkylation unit. The octane number of the alkylate depends mainly upon the kind of alkenes used and upon operating conditions. For example, isooctane results from combining butylene with isobutane and has an octane rating of 100 by definition. There are other products in the alkylate effluent, however, so the octane rating will vary accordingly.
What is the percentage of alkylate in gasoline?
In the gasoline summer pool, the content of alkylate can be as high as 15% because lower Reid vapor pressure (RVP) reduces the possibility to blend butane. For safety reasons, SAAU is the prevalent current technology of choice.
What are high octane hydrocarbons used for?
High octane hydrocarbons are needed to help prevent autoignition of gasoline (knocking) in an engine and to meet recommended engine octane ratings. The process combines an unsaturated light hydrocarbon (propylene, also known as propene, or butylenes, also known as butene) with isobutane to produce alkylate ( al -kuh-leyt).
What is the catalyst for alkylation of gasoline?
Either sulfuric or hydrofluoric acid is used as the catalyst for the alkylation reaction. Alkylate is high in octane but has low volatility and can be added to motor gasoline and aviation gasoline to increase octane while meeting stringent volatility specifications.