Catalytic cracking major products

Catalytic cracking Major product is Cj to C . Few Ti oe-olefins above C4. Aliphat-ics mostly branched. 

Catalytic cracking Major product is Cg to C , few n-o-olefins above C aliphatics mostly branched... 

Hydrocracking is a major process for the production of diesel motor fuel catalytic cracking is its counterpart for the gasoline production. 

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. 

In Europe naphtha is the preferred feedstock for the production of synthesis gas, which is used to synthesize methanol and ammonia (Chapter 4). Another important role for naphtha is its use as a feedstock for steam cracking units for light olefins production (Chapter 3). Heavy naphtha, on the other hand, is a major feedstock for catalytic reforming. The product reformate containing a high percentage of Ce-Cg aromatic hydrocarbons is used to make gasoline. Reformates are also extracted to separate the aromatics as intermediates for petrochemicals. 

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. 

In little more than half of the 25 years covered by this symposium, catalytic cracking has been developed from its first acceptance to a major industrial process. It has served to increase the amount and octane rating of gasoline and the amounts of valuable C3 and C gas components obtainable from petroleum feed stocks over those from thermal cracking alone. It is therefore of interest to seek an explanation of the nature of the products obtained in catalytic cracking in terms of the hydrocarbon and catalyst chemistry which has been developed within the past 25 years. 

It is significant that the mixture yielded propane as the major product (Table III). As noted in our earlier paper on catalytic cracking (6), the predominance of C3 fragments in the cracked products and the absence of isobutane appeared to be a unique property of erionite. Our present data indicate that this is also true for hydrocracking over a dual function erionite. The only exception was that when n-pentane alone was hydro-cracked, equimolal quantities of ethane and propane were found. This shift in product distribution in the presence of n-hexane, a second crackable component, indicated that the reaction path within the intracrystalline space was complicated. 

Fuels. Catalytic Cracking Catalysts are used lo refined a moderately heavy crude oil fraction known as gas oil to gasoline. The net result of the process is a lighter product with a high content of branched-chain and aromatic hydrocarbons, the species responsible for raising gasoline octane levels. The transformations are complex, hut can be considered lo involve ihe following major acid-catalyzed reactions ... 

The major goal of hydroconversion is the cracking of residua with desulfurization, metal removal, denitrogenation, and asphaltene conversion. The residuum hydroconversion process offers production of kerosene and gas oil, and production of feedstocks for hydrocracking, fluid catalytic cracking, and petrochemical applications. 

Other Studies - The complete DOE report (9) includes a sixth case not discussed in this paper. This case is a refinery scheme for production of gasoline by catalytic cracking of a lower hydrogen content feed than in Case 3A. In this case, No. 2 heating oil was a second major product. 

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