FCC Naphtha

The principal class of reactions in the FCC process converts high boiling, low octane normal paraffins to lower boiling, higher octane olefins, naphthenes (cycloparaffins), and aromatics. FCC naphtha is almost always fractionated into two or three streams. Typical properties are shown in Table 5. Properties of specific streams depend on the catalyst, design and operating conditions of the unit, and the cmde properties. 

Two undesirable aspects of FCC naphtha quaUty are that it may contain unacceptably high amounts of foul smelling mercaptans, and that its thermal stabiUty may be too low. Mercaptans are usually found in the light FCC naphtha and may be removed or converted to sulfides and disulfides by a sweetening process such as Merox, developed by UOP. Thermal stabiUty is improved in sweetening processes through removal of cresyUc and naphthenic acids. It may be further improved by clay treating and by addition of oxidation inhibitors such as phenylene diamine. 

Aromatics (vol.%) SR Kero Heavy FCC naphtha LCGO LAGO LCO HAGO... 

Pappal, D. A., and Schipper, P. H., ACS Meeting, Division of Petroleum Chemistry, Chemistry of FCC Naphtha Formation, September 10-15,1989, Miami Beach, Florida. 

FCC gasoline is an important gasoline blending stock world-wide- In Table 4.7, the FCC naphtha has a blending octane of 86 and comprises 38% of the gasoline pool. It contributes 98% of the pool sulfur, 98% of the pool olefins, and 35% of the pool aromatics. The heavy naphtha product from the hydrocracker, along with heavy... 

The increase of 1 unit of the RON corresponds to about 900.000 US per year for a 300.000 tpa hydroisomerization unit (1). In Figure 7.1, several major refinery processes to improve RON are shown these include isomerization, reforming, addition of FCC-Naphtha, alkylation, addition of oxygenates or polygas or butanes. The effect of these options with respect to the new specifications is different for each particular process. Keeping in mind the Californian ban on MTBE and also the fact... 

Feedstock Yield (wt%) FCC Naphtha Coker Naphtha Pyrolysis C4 Pyrolysis C5... 

Miller, J.T., Reagan, W.J., Kaduk, J.A., Marshall, C.L., and Kropf, AJ. Selective hydrodesulfurization of FCC naphtha with supported MoS2 catalysts The role of cobalt. Journal of Catalysis, 2000, 193, 123. 

Description The SUPERFLEX process is a proprietary technology patented by ARCO Chemical Technology, Inc. (now LyondellBasell) and exclusively offered worldwide for license by KBR. It uses a fluidized catalytic reactor system with a proprietary catalyst to convert low-value feedstocks to predominantly propylene and ethylene products. The catalyst is very robust thus, no feed pretreatment is required for typical contaminants such as sulfur, water, oxygenates or nitrogen. Attractive feedstocks include C4 and C5 olefin-rich streams from ethylene plants, FCC naphthas or C4S, thermally cracked naphthas from visbreakers or cokers, BTX or MTBE raffinates, olefin-rich streams removed from motor gasolines, and Fischer-Tropsch light liquids. 

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