High-octane gasoline production

The future demand for high octane gasoline production by catalytic reforming requires extensive conversion of paraffins to aromatics. It is... 

Deactivation for Y-REO-zeolite with different high REO concentrations was studied. The REO can be incorporated into the Y-zeolite around 12% wt and it can be followed by the cell parameter modification. For both fresh and deactivated samples, below 4% wt of REO the total acidity, and the HTI were increased but beyond this REO concentration the total acidity and the HTI decreased as the REO amount increased. The cell parameter and the total acidity diminished for all samples after the deactivation. This behavior was observed when the HTI was analyzed as a ftmction of cell parameter, REO content and total acidity. It is clear that the control of REO content in FCC catalyst is one of the most important task for high octane gasoline production. 

Alkylation combines lower-molecular-weight saturated and unsaturated hydrocarbons (alkanes and alkenes) to produce high-octane gasoline and other hydrocarbon products. Conventional paraffin-olefin (alkane-alkene) alkylation is an acid-catalyzed reaction, such as combining isobutylene and isobutane to isooctane. 

These are effective high-octane gasoline additive oxygenates. The conversion of isobutane into isopropyl, methyl ketone, or isopentane into isobutyl, methyl ketone is illustrative. In this reaction, no branched carboxylic acids (Koch products) are formed. 

LPG recovered from natural gas is essentially free of unsaturated hydrocarbons, such as propylene and butylenes (qv). Varying quantities of these olefins may be found in refinery production, and the concentrations are a function of the refinery s process design and operation. Much of the propylene and butylene are removed in the refinery to provide raw materials for plastic and mbber production and to produce high octane gasoline components. 

The cumene product is 99.9 wt % pure, and the heavy aromatics, which have a research octane number (RON) of 109, can either be used as high octane gasoline-blending components or combiaed with additional benzene and sent to a transalkylation section of the plant where DIPB is converted to cumene. The overall yields of cumene for this process are typically 97—98 wt % with transalkylation and 94—96 wt % without transalkylation. 

Sasol Fischer-Tropsch Process. 1-Propanol is one of the products from Sasol s Fischer-Tropsch process (7). Coal (qv) is gasified ia Lurgi reactors to produce synthesis gas (H2/CO). After separation from gas Hquids and purification, the synthesis gas is fed iato the Sasol Synthol plant where it is entrained with a powdered iron-based catalyst within the fluid-bed reactors. The exothermic Fischer-Tropsch reaction produces a mixture of hydrocarbons (qv) and oxygenates. The condensation products from the process consist of hydrocarbon Hquids and an aqueous stream that contains a mixture of ketones (qv) and alcohols. The ketones and alcohols are recovered and most of the alcohols are used for the blending of high octane gasoline. Some of the alcohol streams are further purified by distillation to yield pure 1-propanol and ethanol ia a multiunit plant, which has a total capacity of 25,000-30,000 t/yr (see Coal conversion processes, gasification). 

Polymerization - Polymerization is occasionally used to convert propene and butene to high octane gasoline blending components. The process is similar to alkylation in its feed and products, but is often used as a less expensive... 

To obtain light ends conversion, alkylation and polymerization are used to increase the relative amounts of liquid fuel products manufactured. Alkylation converts olefins, (propylene, butylenes, amylenes, etc.), into high octane gasoline by reacting them with isobutane. Polymerization involves reaction of propylene and/or butylenes to produce an unsamrated hydrocarbon mixture in the motor gasoline boiling range. 

The catalyst must also be selective to valuable products. Gasoline is desirable, so a lot must be produced, but it must be high octane gasoline. Cj s and C s are sometimes required for polymerization, alkylation and chemical production. Certain catalysts give high yields of these compounds, especially the imsaturated components. Gases, such as methane and hydrogen, are undesirable so the yield of these products must be suppressed. 

Cj s and C s include propane, propylene, normal butane, isobutane, and butylene. Propylene and butylene are used to make ethers and alkylate, which are blended to produce high-octane gasoline. Most gas plants also include treating facilities to remove sulfur from these products. 

Penex [Pentane and hexane isomerization] A process for converting n-pentane and n-hexane and their mixtures into branched-chain pentanes and hexanes of higher octane number by catalytic isomerization. The catalyst is similar to the Butamer catalyst. The product is used in high-octane gasoline. First commercialized by UOP in 1958. More than 75 units were operating as of 1996. 

Stratco A process for making a high-octane gasoline component by alkylation of C3 - C5 hydrocarbons with isobutane, catalyzed by sulfuric acid. The product is known as an alkylate. Operated in several oil refineries in the United States. 

Introduction of zeolites into catalytic cracking improved the quality of the product and the efficiency of the process. It was estimated that this modification in catalyst composition in the United States alone saved over 200 million barrels of crude oil in 1977. The use of bimetallic catalysts in reforming of naphthas, a basic process for the production of high-octane gasoline and petrochemicals, resulted in great improvement in the catalytic performance of the process, and in considerable extension of catalyst life. New catalytic approaches to the development of synthetic fuels are being unveiled. 

Thus, a large focus of FCC catalyst research involves control of the density and location of acid sites in order to control product selectivity, product quahty and coke make. In a landmark publication Pines [30] demonstrated how widely spaced framework A1 sites may be utilized to produce high octane gasolines by decreasing hydrogen transfer reactions which in turn results in preservation of olefins. 

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