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Alkyl aromatics, catalytic cracking

Here we will describe the main aspects of the chemistry involved in selected zeolite-catalyzed processes in the field of oil refining and petrochemistry, such as short paraffin aromatization, skeletal isomerization of n-paraffins and n-olefins, isoparaffin/olefin alkylation, and catalytic cracking. [Pg.30]

Furthermore, the major problem of reducing aromatics is focused around gasoline production. Catalytic reforming could decrease in capacity and severity. Catalytic cracking will have to be oriented towards light olefins production. Etherification, alkylation and oligomerization units will undergo capacity increases. [Pg.411]

Catalysis. As of mid-1995, zeoHte-based catalysts are employed in catalytic cracking, hydrocracking, isomerization of paraffins and substituted aromatics, disproportionation and alkylation of aromatics, dewaxing of distillate fuels and lube basestocks, and in a process for converting methanol to hydrocarbons (54). [Pg.457]

Most of the commercial zeolite catalyzed processes occur either through acid catalysis fluid catalytic cracking (FCC), aromatic alkylation, methanol to olefins (MTO),... [Pg.234]

The catalytic cracking of four major classes of hydrocarbons is surveyed in terms of gas composition to provide a basic pattern of mode of decomposition. This pattern is correlated with the acid-catalyzed low temperature reverse reactions of olefin polymerization and aromatic alkylation. The Whitmore carbonium ion mechanism is introduced and supported by thermochemical data, and is then applied to provide a common basis for the primary and secondary reactions encountered in catalytic cracking and for acid-catalyzed polymerization and alkylation reactions. Experimental work on the acidity of the cracking catalyst and the nature of carbonium ions is cited. The formation of liquid products in catalytic cracking is reviewed briefly and the properties of the gasoline are correlated with the over-all reaction mechanics. [Pg.5]

The acid-catalyzed reactions of olefin polymerization and aromatic alkylation by olefins have been very well explained by the carbonium ion mechanism developed by Whitmore (21). This mechanism provides the basis of the ensuing discussion, which is devoted to the application of such concepts (7,17) to catalytic cracking systems and to the provision of much added support in terms of recently developed structural energy relationships among hydrocarbons and new experimental evidence. [Pg.9]

The liquid products of catalytic cracking (obtained in accordance with the described principles) have been omitted from consideration thus far, except in the case of the alkyl aromatics. To the refiner, the liquid obtained is of prime importance, both as gasoline and heavier intermediate oils. [Pg.13]

Saturated constituents contribute less to the vacuum gas oil than the aromatics but more than the polar constituents that are now present at percentage rather than trace levels. The vacuum gas oil itself is occasionally used as heating oil but most commonly it is processed by catalytic cracking to produce naphtha or by extraction to yield lubricating oil. Within the vacuum gas oil saturates, the distribution of paraffins, /iso-paraffins and naphthenes is highly dependent upon the petroleum source. The bulk of the vacuum gas oil saturated constituents consist of /Iso-paraffins and naphthenes. The naphthenes contain from one to more than six fused rings and have alkyl substituents. For mono- and di-aromatics, the alkyl substitution typically involves one long side chain and several short methyl and ethyl substituents. [Pg.107]

The catalytic alkylation of isobutane with C3—C5 alkenes was commercialized in the US during WW II. Blending the alkylate product with catalytically cracked gasoline provided high-octane aviation fuel. The introduction of aromatic and oxygenated fuel additives, such as methyl t-butyl ether (MTBE), pushed alkylation to the sidelines. However, in the 1990s, when the environmental effects of such additives were realized, alkylation regained its importance [191]. [Pg.168]

Figure 9 summarizes some of the intermolecular reaction pathways deemed important in catalytic cracking. For example, hydrogen transfer between paraffin and olefin and between olefin and naphthenes can occur to form energetically more stable reaction products (37,38). Transalkylation, i.e., scrambling of short chain alkyl groups on aromatics, is also prevalent. Condensation reactions have been implicated in coke formation pathways. [Pg.305]

To conclude this section, it is necessary to state that besides their application in catalytic cracking, amorphous silica-alumina acid catalysts have been applied in other hydrocarbon transformations, such as isomerization of olefins, paraffins, and alkyl aromatics, the alkylation of aromatics with alcohols and olefins, and in olefin oligomerization [55],... [Pg.429]

Catalytic Cracker Bottoms (CCB) which is the heavy residue from the catalytic cracking of petroleum distillate is a common aromatic feedstock used for synthetic carbons and pitch production. CCB, like other heavy aromatic feedstock, is composed of alkyl-substituted polycondensed aromatics with a very wide molecular weight distribution. [Pg.134]

Refining of the catalytically cracked aviation base stock was at first done with sulfuric acid, merely to remove unsaturates (133). However, it was found that passing the raw aviation fraction a second time over the cracking catalyst (catalytic re-treating) resulted in a product with less olefins, more aromatics, and improved response to tetraethyllead, and thus decreased sharply the proportion of alkylate required in the aviation blend (51). These effects are illustrated in Table VII. The effect of retreating a naphtha from a high-temperature first-pass operation is shown in Table VIII, and the quality of the aviation base stock is compared... [Pg.361]


See other pages where Alkyl aromatics, catalytic cracking is mentioned: [Pg.197]    [Pg.631]    [Pg.76]    [Pg.67]    [Pg.233]    [Pg.102]    [Pg.524]    [Pg.8]    [Pg.41]    [Pg.215]    [Pg.32]    [Pg.38]    [Pg.584]    [Pg.148]    [Pg.305]    [Pg.113]    [Pg.113]    [Pg.113]    [Pg.114]    [Pg.515]    [Pg.81]    [Pg.77]    [Pg.56]    [Pg.64]    [Pg.66]    [Pg.66]    [Pg.148]    [Pg.365]    [Pg.250]    [Pg.335]    [Pg.186]    [Pg.238]    [Pg.360]   
See also in sourсe #XX -- [ Pg.193 , Pg.194 , Pg.240 ]




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Alkylated aromatics

Alkylation aromatic

Aromatic alkylations

Aromatics alkylation

Aromatics, catalytic cracking

Catalytic alkylations

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