Reforming stock

In the field of aromatic separation, the trend of research is toward isolation of pure compounds for chemical purposes. Benzene, toluene, and some of the C8 aromatics have been separated and used commercially. However, the physical properties of the C9 and Cio aromatic hydrocarbons found in reformed stocks show that other aromatics could be separated from these mixtures by distillation, crystallization, or extraction processes. It is reasonably certain that if sufficient demand develops for the pure compounds, processes for their separation will become available. Present information indicates that perhaps methylethylbenzenes and trimethylbenzenes could be isolated in relatively high purity by distillation from aromatic stocks obtained by hydroforming, but no information is available as to their industrial uses. Similarly, durene (1,2,4,5-tetramethylbenzene) possibly could be isolated from its homologs by crystallization. Furthermore, large... 

TABLE IV. - Properties of reforming stock, diesel fuels, and fuel oil... 

Reforming stock C-B diesel T-T di esel S-M diesel Fuel oil... 

The preceding information indicates the paths to follow in order to obtain stocks of high octane number by refining. The orientation must be towards streams rich in aromatics (reformate) and in isoparaffins (isomerization, alkylation). The olefins present essentially in cracked gasolines can be used only with moderation, considering their low MONs, even if their RONs are attractive. 

Catalysts in this service can deactivate by several different mechanisms, but deactivation is ordinarily and primarily the result of deposition of carbonaceous materials onto the catalyst surface during hydrocarbon charge-stock processing at elevated temperature. This deposit of highly dehydrogenated polymers or polynuclear-condensed ring aromatics is called coke. The deposition of coke on the catalyst results in substantial deterioration in catalyst performance. The catalyst activity, or its abiUty to convert reactants, is adversely affected by this coke deposition, and the catalyst is referred to as spent. The coke deposits on spent reforming catalyst may exceed 20 wt %. 

Fig. 1. Reaction composition profile. Reforming at 794 K, 2620 kPa. Zone A dehydrogenation zone zone B isomerization zone zone C hydrogenation and cracking zone. [Charge stock A, hexane (HEX) , benzene (BENZ) V, cyclohexane (CH) O, methylcyclopentane (MCP).]...

Also, the optimization and planning of crude allocations in Mobil s worldwide refinery system is the principal objective of Mobil s supply and distribution planning group. Overall corporate profits can be maximized by proper crude allocations to the various refineries. Similar to the refinery LPs, the reformer representation in the crude supply and distribution LP was improved. Table XX gives an example of how sensitive reformer operation can depend on the type of naphtha reformed. A significant improvement in performance and octane potential results from processing a naphthenic stock compared to a paraffinic stock. This improved performance must be balanced against differences in crude cost. 

GASOLINE BLENDING STOCKS REFORMATES None Flammable Liquid 1 3 0... 

Gasoline Blending Stocks Reformates — Fire Hazards Flash Point (deg. F) < 0 CC ... 

A comparison has been made of Platforming and of thermal reforming from the standpoint of yield-octane number relationships, product properties, hydrocarbon types, and with respect to the nature of chemical reactions responsible for improvement of octane number. Comparison is based on studies of thermal reforming in a commercial operation at a Pennsylvania refinery and in a pilot plant on a midcontinent naphtha and in pilot plants and laboratory Platforming on the same stocks. 

Correlations presented in the middle thirties enabled the prediction of octane number improvement resulting from thermal reforming (7, 21). They have continued to appear in the literature (6, 20). Improvement of the octane number of naphthas has been the principal function of thermal reforming, but Egloff (8) discusses its usefulness also for the production of light olefins which provide feed stocks for alkylation or polymerization processes. To show the distinct improvement in the yield-octane relationship realized by the catalytic polymerization of C3 and C4 olefins produced by thermal reforming, Mase and Turner (16) present experimental data at various reforming severities for two naphthas. 

The economics of thermal reforming and hydroforming of sweet and sour heavy straight-run naphthas have been compared recently by McLaurin, McIntosh, and Kaufman (15). They concluded that the relative economics of the two processes were virtually the same for both feed stocks. 

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