Reforming reactions high octane

The most common HDS catalyst consists of 2- to 3-nm-wide, singlelayered MoS nanoparticles, promoted with cobalt or nickel and supported on alumina. Only the edges of the S-Mo-S layers are known to be active. Sophisticated surface science studies have shown that even in such a well-defined nanostructure, two different types of active sites are present. In the reformation step, the Pt-Re-alumina-based catalyst catalyzes dehydrogenation and isomerization reactions. High octane gasoline must be rich in aromatics and branched chain paraffins, and this is achieved by subjecting crude gasoline to these reactions. 

Powerforming is basically a conversion process in which catalytically promoted chemical reactions convert low octane feed components into high octane products. The key to a good reforming process is a highly selective dual-function catalyst. The dual nature of this catalyst relates to the two separate catalyst functions atomically dispersed platinum to provide... 

The predominant reaction during reforming is dehydrogenation of naphthenes. Important secondary reactions are isomerization and dehydrocyclization of paraffins. All three reactions result in high-octane products. 

The process of catalytic reforming is utilized for the production of high-octane-number compounds from lower-octane-number fractions. It is an endothermic process which requires heat and a catalyst in order to maintain a constant reaction rate. Hydrogen is also produced in significant quantities through the reforming process. 

The first polymerizations were free radical reactions. In 1933 researchers at ICI discovered that ethene polymerizes into a branched structure that is now known as low density polyethene (LDPE). In the mid- 50s a series of patents were issued for new processes in which solid catalysts were used to produce polyethene at relatively low pressures. The first was granted to scientists at Standard Oil (Indiana) who applied nickel oxide on activated carbon and molybdenum oxide on alumina. Their research did not lead to commercial processes. In the late 40s Hogan and Banks of Phillips were assigned to study the di- and trimerization of lower olefins. The objective was to produce high octane motor fuels. When they tried a chromium salt as promoter of a certain catalyst (Cr was a known reforming... 

Catalytic Reforming A catalytic reaction of heavy naphtha(1) used to produce high-octane gasoline. The byproducts are hydrogen and light hydrocarbons the primary reaction is dehydrogenation of naphthenes to produce aromatics. Some reshaping of paraffins to produce aromatics and some isomerization of paraffins to produce isoparaffins also occur. 

The reforming of petroleum fractions boiling between about 90 and 200°C. to high octane gasolines constitutes one of the largest scale industrial catalytic operations of our times. The quantity processed over platinum catalysts exceeds 2 X 10 liters/day. A majority of the reactions involved are polystep hydrocarbon conversions (see refs. 10,11, and the extensive review of the art by Ciapetta et al., 31). 

It is well known that zeolites with pintail structures are active in reactions of isomerization, cracking, aromatization, alkylation, etc., which makes possible their use as an active component of catalysts for a number of processes. Thus, ZSM-5 zeolites are used as catalysts for the transformation of lower alkanes into aromatics [1] Ni/ZSM-5 zeolite is applied in the M-Forming process to increase octane numbers of reformates [2] catalysts prepared on the basis of pentasil-type zeolites are employed in zeoforming - the process of unleaded high-octane gasoline obtaining from gas condensate and gas gasoline fractions [3-7]. 

There are situations where support acidity has a positive influence, influencing the main reaction. The support adds dual functionality to the overall catalysis, as best demonstrated with catalytic reforming/ The objective in this process is to convert low octane components of naphtha, typically normal paraffins and naphthenes, into high-octane iso-parafHns and aromatics. Low loadings of Pt type metals on AljOj are used for this purpose. Metallic Pt dehydrogenates naphthenes to aromatics but cannot isomerize or cyclize normal paraffins. This is accomplished through the acidic function of the support, as shown for n-hexane ... 

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