Reduced crude conversion process

Faced with the need of obtaining more transportation fuels from a barrel of crude, Ashland developed the Reduced Crude Conversion Process (RCC ). To support this development, a residuum or reduced crude cracking catalyst was developed and over 1,000 tons were produced and employed in commercial operation. The catalyst possessed a large pore volume, dual pore structure, an Ultrastable Y zeolite with an acidic matrix equal in acidity to the acidity of the zeolite, and was partially treated with rare earth to enhance cracking activity and to resist vanadium poisoning. 

A number of refiners have processed residue containing feedstocks in commercial FCC units. Feeds with as much as 5.1%w RCR ( 6.5%w CCR) and 85 ppm Ni + V have been processed in Phillips Borger Refinery.(4) Ashland has processed feedstocks of up to 7.1%w RCR ( 8.5%w CCR) and 85 ppm Ni + V in their RCC (Reduced Crude Conversion) process.(5,6) A commercial scale ART (Asphalt Residual Treating) unit has processed residues containing levels of contaminants as high as 13.5%w RCR and 300 ppm Ni + V (7,8). However, in typical day-to-day operation of residue cat crackers, feedstock quality is not as extreme as those illustrated above. 

Of course, the reduced crude conversion process is not 100% efficient. By this it is meant that to date no catalyst and operating conditions have been developed which completely remove saturates, monoaromatics, diaromatics, and alkyl substituents of polynuclear aromatics from the slurry oil. Therefore, to predict slurry oil plus coke yield one must determine what proportion of each molecular type present in the reduced crude feedstock remains in the slurry oil and coke. 

A. Zandona, 0. J. Busch, L. E. Hettinger, W. P., Jr. "Reduced Crude Conversion Symposium on Production, Characterization and Processing of Heavy Oils, Tar Sand Bitumens, Shale Oils and Coal-Derived Liquids", University of Utah, 1981. 

RCC [Reduced crude oil conversion] A process for converting reduced crude oil (a petroleum fraction), and other petroleum residues, into high-octane gasoline and other lighter fuels. Based on the FCC process, but adapted to accommodate higher levels of metal contaminants which can harm the catalyst. Developed by Ashland Oil Company and UOP and... 

RCD Unibon [Reduced crude desulfurization] Also known as the Black oil conversion process (BOC). A process for removing organic sulfur-, nitrogen-, and metal-compounds from heavy petroleum fractions. Different catalysts are used for different oils. Developed and licensed by UOP. 

Coking is a thermal process for the continuous conversion of heavy, low-grade oils into lighter products. The feedstock can be reduced crude, straight-run residua, or cracked residua, and the products are gases, naphtha, fuel oil, gas... 

L.E. Busch, W.P. Hettinger, Jr., Richard P. Krock, "Reduced Crude Oil Conversion in Commercial RCC and ART Process Operations (Paper No. AM-84-50), 1984 NPRA Annual Meeting, March 25-27, 1984, San Antonio, Texas. 

Sulfur Sulfur is present in all lube plant feedstocks fractionated from crude oil and its content may be up to several percentage points. Solvent refining removes some but not all, therefore such stocks with no further treatment can contain up to several mass percent of sulfur. Hydrofinishing of solvent refined stocks can reduce this level substantially. Base stocks from conversion processes will have sulfur levels in the low parts per million (ppm) range since sulfur is relatively easily removed in severe hydroprocessing. 

Houdresid process). Although the upper economic limit of catalyst contamination has been reported to be about 200 ppm of nickel and vanadium on the catalyst, such a supposedly poisoned catalyst was used in the commercial operations. After more than a million barrels of reduced crude oil (Ni, 4.6 Va, 6.1 and Fe, 9.4 ppm) had been processed, the activity of the catalyst had dropped from 26 to only 23.6 by the Cat. A activity test, but scarcely any addition of catalyst, other than to replace the attrition of 0.4-0.5 lb per bbl of feed, was necessary. Meanwhile, the iron had risen and stabilized at 1.4 per cent of the catalyst, and the nickel and vanadium to over 400 ppm each. At the conversion of about 68 per cent, yields were nearly the same as those indicated in Fig. 21-3, except that the coke yield was somewhat high (7 to 8.2 per cent rather than 5.5 to 6.5), and the B-B cut was smaller (12 to 15 per cent rather than 18). 

Data from in vitro activity assays with these purified recombinant proteins can typically be interpreted much more easily than data obtained from experiments with crude or partially purified protein extracts, because (1) there will be no competing proteins with similar activity present in the assay, and (2) there will no enzymes present that convert the product generated by the enzyme of interest, and hence reduce the effective product concentration. A potential downside of the use of recombinant protein over crude extracts is the fact that critical co-factors that will ensure proper activity may not be present in the purified protein fraction. If that is the case, the researcher will have to empirically determine which co-factor and at what concentration needs to be included in the assay. Another consideration is that the native protein may have undergone post-translational processing, such as acetylation, glycosylation, myristoylation, etc. These modifications may not occur or may not occur properly when the protein is expressed in bacterial, fungal or insect cells. Assuming that these potential problems do not occur or can be dealt with, the availability of pure recombinant protein will enable the determination of substrate specificity, as well as kinetic experiments in which the rate of conversion is measured as a function of time and/or substrate concentration. 

The chemical character of the unconverted asphaltenes is also a function of processing. Both the H/C and O/C atomic ratios declined in a regular manner as conversion progressed. In some cases, the oxygen content was reduced to that typically found for pentane-soluble oils (about 2%). At the same time, the atomic H/C ratio of the residual asphaltenes was reduced to values considerably lower (<0.7) than that of the coal. The relative oxygen content may be used as a crude indicator of the severity of hydroprocessing experienced by a particular asphaltene. 

The refiner s position on inorganic solids and salt removal is that as much of these contaminants (as is cost-effective) should be removed from the incoming crude oil into the wash water by the desalting process. Excess chloride salts become catalyst poisons that promote excessive catalyst consumption or reduce conversion in the cracking and treating processes. Chloride salts also compromise the reliability of refinery overheads where, because of hydrolysis upon heating, they form highly corrosive hydrochloric acid in the overhead system. (The refinery overhead is the equipment, such... 

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