Hydrocarbon processing fractionation

In general, when the product is a fraction from cmde oil that includes a large number of individual hydrocarbons, the fraction is classified as a refined product. Examples of refined products are gasoline, diesel fuel, heating oils, lubricants, waxes, asphalt, and coke. In contrast, when the product is limited to, perhaps, one or two specific hydrocarbons of high purity, the fraction is classified as a petrochemical product. Examples of petrochemicals are ethylene (qv), propylene (qv), benzene (qv), toluene, and xylene (see Btx processing). 

Source Daubert, T. E., Petroleum Fraction Distillation Interconversions, Hydrocarbon Processing, September 1994, pp. 75-78. 

There is some similarity between the cracking of petroleum and the cracking of biomass. However, biomass is more complex chemically both in terms of structrual types and functional groups. In petrochemistry, hydrocarbons are fractionated and they are then functionalized by oxidation, halogenation, nitration and other chemical processes so as to add value. The commodity chemicals are then built up into more complex molecules using such popular synthetic methods as Friedel Craft reactions, Michael and aldol condensations, and Heck and Suzuki couplings. The speciality products of these reactions are then further elaborated into formulations for use in everyday applications ranging from personal care... 

Demex [Demetallization by extraction] A process for removing metal compounds from heavy petroleum fractions, after vacuum distillation, by solvent extraction and supercritical solvent recovery. The solvent is typically a mixture of octanes and pentanes. Developed jointly by UOP and the Institute Mexicano del Petroleo seven units were operating in 1988. Hydrocarbon Process., 1988, 67(9), 66. 

Hydropol A process for co-hydrogenating u-butenes with olefinic gasoline fractions. Developed by the Institut Frangais du Petiole as part of its polymer gasoline process. Hydrocarbon Process., 1980, 59(9), 219. 

In the Tervahl T process (LePage et al., 1987 Hydrocarbon Processing, 1998) (Figure 8-9), the feedstock is heated to the desired temperature using the coil heater and heat recovered in the stabilization section and held for a specified residence time in the soaking drum. The soaking drum effluent is quenched and sent to a conventional stabilizer or fractionator where the products are separated into the desired streams. The gas produced from the process is used for fuel. 

The activation of methane [1] is also included as one of the most desired yet not technically viable reactions. Abundant amounts of methane occur with crude oil and as gas in remote locations it is also produced in large quantities during hydrocarbon processing. A large fraction of this methane is flared, because economical use or transportation is not possible. This gas and the abundant resources of methane gas hydrates would make a very suitable feedstock for higher hydrocarbons, if its activation to produce molecules other than synthesis gas were feasible. Despite enormous fundamental and practical efforts [1-5], no applicable method has yet been found for creation of ethylene, methanol, or formaldehyde from methane. 

Fig. 18.14. Crude distillation—Foster Wheeler. Includes exchanger heaters (1,3), desalter process (2), fired heater (4), main fractionator (5), overhead gas accumulator (6), sidestream strippers (7,8,9,10), second fired heater (11), and vacuum fractionator (12). (Source Hydrocarbon Processing, 2004 Refining Process Handbook. CD-ROM. September 2004 copyright 2004 by Gulf Publishing Co., all rights reserved.)...

Fig. 18.24. Alkylation—UOP LLC. Solid Catalyst System removes impurities from the feed (1), clean feed, recycled isobutene, and catalyst and feed to main reactor (2), and final product are separated in fractionation section (3). (Hydrocarbon Processing, 79, No. 11. Nov. 2000 copyright 2000 by Gulf Publishing Co., all rights reserved.)...

Golden, S. W., et al., Use Better Fractionation to Manage Gasoline Sulfur Concentration, Hydrocarbon Processing, 67-72 (Feb. 2002). 

The hydrocarbon composition of gasoline produced from different raw materials under the same process conditions may essentially differ individually as well as in groups. The main differences are observed in the composition of the paraffin-naphthene fraction of gasoline, and aromatics are represented basically by the toluene-xylene fraction. As a result of the transformation of hydrocarbon feedstocks over H-ZSM-5/AI2O3 catalyst, hydrocarbon and fraction composition of liquid products widen which leads to an increase of the end boiling point of the catalysate. Simultaneously, the formation of Ci - C4 hydrocarbons and of a small amount of H2 (not more than 3-4 wt % in the gas phase) occurs. The composition of the gaseous products obtained (P>5 MPa) differs only slightly. 

Reading, W. W, How DOW makes phenol from toluene", Hydrocarbon Processing, 43 (11) 173-176 (1964). Pecka, L, Singer, P., Cumene/phenol purifreation by fractions melting" Europ. Chem. News, Large Plant SuppL, 82-84, (27 SepL 1968).. ... 

This discussion will be concerned with integrated hydrocarbon processing, starting with crude oil as feedstock. Plants charging pre-processed fractions such as LPG, naphtha, gas oil, natural gasoline, etc. are definitely outside this concept since they imply a reliance upon the byproducts of other hydrocarbon processing operations. The proper selection of the products to be produced from this crude oil input and the process steps used to obtain them and their scale will determine the economic feasibility of the scheme. 

From N. P. Lieberman, "Packing Expands Low-Pressure Fractionators," Hydrocarbon Processing. April 1984. 

FIGURE 8-2 Observed heat balance in a fluid cracker unit fractionator (after Liebertnan, courtesy Hydrocarbon Processing, April 1984)... 

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