US3245902A - Demetallization of high boiling petroleum fractions - Google Patents

Description

% METALS REMAINING April 1966 c. E. ADAMS ETAL 3,245,902

DEMETALLIZATION OF HIGH BOILING PETROLEUM FRACTIONS Filed Feb. 28, 1962 3 Sheets-Sheet 2 FIGURE 2 so 7o o 20 40 so so I00 120 MINUTES CONTACT TIME Clark Edwdrd Adams Glen Porter Humnor INVENTORS Charles Newton Kimberlin, Jr.

BY R0 Wk PATENT ATTORNEY April 12, 1966 c. E. ADAMS ETAL DEMETALLIZATION OF HIGH BOILING PETROLEUM FRACTIONS Filed Feb. 28, 1962 5 Sheets-Sheet 3 FIGURE 3 O o O m w s 4 a MINUTES CONTACT TIME INVENTORS Clark Edward Adams Glen Porter Humner Charles Newton Kimberlin, Jr.

BY 7% aL Ed a PATENT ATTORNEY United States Patent 3,245,902 DEMETALLIZATIUN OF HIGH BGILENG PETRULEUM FRACTIONS Clark Edward Adams, Baton Rouge, Glen Iorter Hamper,

East Baton Rouge, and Charles Newton Kimberlin, In,

Baton Rouge, 1a., assignors to Esso Research and Engineering (Iompany, a corporation of Delaware Filed Feb. 23, 1962, Ser. No. 176,377 12 (Jlaims. (Cl. 2ti8252) The present invention relates to the upgrading of hydrocarbon oils containing metallic contaminants and high boiling constituents boiling above 950 F. More particularly, the present invention relates to the upgrading of crude oil and residual oil fractions to produce at once superior feeds to catalytic cracking operations and metal free aromatic streams adapted to coking and similar processes. Still more particularly, the present invention relates to a combination process for producing important petroleum refinery intermediate streams by a technique involving the use of liquid hydrofluoric acid in a manner superior to those hitherto known.

The present invention relates to the upgrading of hydrocarbon oils and more particularly relates to an improved process for removing metallic contaminants from high boiling petroleum fractions by contacting said fractions with concentrated hydrogen fluoride.

The adverse effects of iron, nickel, vanadium and other metallic contaminants found in petroleum fractions boiling above 950 F. upon catalysts employed in petroleum processing operations and upon combustion equipment in which such high boiling fractions are used as fuels have long been recognized. In catalytic cracking operations, for example, very small concentrations of such contaminants in the feed to the cracking unit lead to the rapid poisoning of the catalyst, causing a significant decrease in the yield of cracked products, an increase in the production of coke and gases, and a marked shortening of the catalyst life. Metallic contaminants present in residual fuels have similarly deleterious effects in that they attack the refractories used to line boilers and combustion chambers; cause slagging and deposits on boiler tubes, combustion chamber walls and blades of gas turbines; and severely corrode high temperature metallic surfaces with which they come in contact.

Much research has been devoted to the problem of developing methods for removing metallic contaminants from high boiling petroleum fractions in order to overcome these difficulties. Heretofore, no wholly satisfactory method for accomplishing this had been found. The contaminants are largely unaffected by conventional desalting techniques, solvent extraction, chemical treatment, and other methods proposed in the past. It has therefore generally been necessary to limit the feed stocks to catalytic cracking units and other catalytic processes to those fractions which boil below the range in which metallic contaminants are found and to avoid as much as possible the use in residual fuels of high boiling residual fractions containing high contaminant concentrations.

The present invention provides a new and improved method for removing metallic contaminants from high boiling petroleum fractions which is highly effective, results in improved yields of decontaminated oil, and is economically attractive. In accordance with the invention, the contaminants in the oil are removed by treat- "Ice ing the contaminated fraction with hydrofluoric acid in the liquid phase under controlled conditions and are thereafter segregated from the oil by settling, filtration, centrifugation, or the like. The hydrofluoric acid acts apparently as a selective metal cleaving agent toward the contaminants and does not react chemically with other constituents of the oil to form an acid sludge. The acid in the present process may be used repeatedly and, since little or no oil is consumed in reaction with the acid, the product yields are high. The process of the invent-ion is applicable to the treatment of high boiling gas oils, deasphalted oils, residual fractions and crude oils.

The process of the invention is based upon studies made of the nature and properties of the metallic contaminants found in heavy g-as oils and in residual fractions boiling in excess of 950 F. It has been found that such contaminants are innate constituents of the oil and are usually complex organic chelate compounds of the porphyrin type. Two forms of the contaminants have been observed, one volatile at temperatures between about 1050 and 1250" F. and the other substantially non-volatile at such temperatures. It is believed that the volatile contaminants are single, monomeric porphyrins and that the non-volatile compounds are formed by the polymerization of two or more such porphyrins.

The non-volatile contaminants are of low solubility in the oil and are normally colloidally dispersed therein. The volatile contaminants, on the other hand, are in true solution. Because of entrainment during fractionation of the oil, both volatile and non-volatile contaminants may be present in distillate petroleum fractions boiling as low as 950 F. or in some instances even slightly lower. It is possible that the colloidally-dispersed, non-volatile contaminants are initially coagulated by treatment with the hydrofluoric acid. The exact mechanism of the coagulation is not fully understood, but it may be that the colloidal metals are stabilized in the oil primarily by solvation rather than by electrical charges and the acid apparently destroys the solvating films surrounding the colloidal metals and then acts as an electrolyte to effect their coagulation. The mechanism by which the hydrofluoric acid removes metals from the porphyrins and complexes, regardless of Whether these are in soluble or colloidal form, is probably one involving selective cleavage of the porphyrin molecule. The metals are recovered as a solid comprising greater than 10 wt. percent metal in a carbonaceous, coke-like material that is insoluble in both the oil and the aqueous-acid phases while the bulk of the porphyrin molecule remains in the oil. This is a substantially different phenomenon from that which takes place where these same metal contaminated stocks are treated with other acidic reagents, such as H or hydrogen chloride or other halogen acids. Here the principal reaction is a coagulating step involving precipitation of the whole molecule, i.e., the porphyrin molecule itself is precipitated, along With asphaltenes and other high molecular weight hydrocarbons associated with the organic metallic complex. Furthermore, prior art acid treating processes do not affect significantly the volatile oil-soluble porphyrins. Through these soluble metals, and about one-third of the vanadium in Bachaquero crude is in this form, may be converted to the insoluble colloidal form by such techniques as heat soaking or solvent precipitation, this not only requires an extra processing step, but also is impractical for removing small concentrations of metals from gas oils. Thus by operating in accordance with the present invention, no preliminary deasphalting, solvent precipitating, or thermal treating step is necessary.

The concentration of metallic contaminants and the ratio of volatile to non-volatile compounds in crude oils vary considerably. The metals content of any distillate fraction will therefore depend upon the type and concentration of contaminants in the crude oil from which the fraction was distilled, the boiling range of the fraction, and the amount of entrainment which took place during the distillation. Heavy gas oils distilled from typical crudes may contain from about 1 to about 20 pounds of metallic contaminants per 1000 barrels. Residual fractions and gas oils derived from crudes which are particularly high in contaminants may contain as much as 200 pounds of metal per 1000 barrels.

Besides the metallic contaminants normally present in crude oil and residual oil fractions, there are also present other impurities having a deleterious effect upon cracking catalyst and the catalytic cracking process. First and foremost are the compounds, mostly polynuclear aromatics, which produce Conradson carbon and heavy coking of the catalyst. Nitrogen, sulfur and other impurities have a deleterious effect and require reduction before a feed suitable for catalytic cracking is achieved. Some refinery processes for catalytic cracking also include a deasphalting step to remove high boiling unsaturated compounds that tend to form high coke.

The process of the present invention is made possible by the discovery of the demetallizing properties of liquid phase HF treatment under certain critical conditions, namely, at temperatures of 200 to 400, preferably 250 to 375 F., for to 100, preferably to 60, minutes. It has been found that only at these conditions can demetallization to low levels be realized Without incurring cracking of feed stock. Lower temperatures fail to give effective metals removal and higher temperatures degrade the product stream. The invention involves the initial selective demetallization of the metal-containing, undeasphalted crude or residua under demetallizing conditions, followed by a selective solvent extraction with the same HF under solvent extraction conditions, preferably in the presence of an added light hydrocarbon solvent. After phase separation, there is recovered a paraffinic type oil ideally suited for catalytic cracking and substantially completely free of metals as well as very low in sulfur, nitrogen, aromatics and Conradson carbon impurities. Also recovered is a highly aromatic stream containing the metals in suspension. These metal compounds are readily filterable and since substantially no coke or sludge resulted from the demetallizing step, the metals are substantially the only insoluble constituents of the extract phase, and are recovered as a salt; the resulting product yield is thus high. Furthermore the extract, after filtration, water washing, or other separating technique, has a metal content substantially lower than the feed, an important factor in preparing feed stocks for coking, etc.

The use of hydrogen fluoride as a selective solvent for aromatic streams is well known. However, without the demetallizing step of the present invention, selective extraction will not result in a metal-free catalytic cracking feed stock nor the aromatic-rich, low-metal fuel oil.

The exact nature and objects of the present invention may be more fully understood from the following description and drawing which illustrates a preferred embodiment of the invention.

FIGURE 1 depicts an integrated process operated in accordance with the present invention.

FIGURES 2 and 3 graphically illustrate the criticality of the present process conditions for effecting demetalliz-ation to low levels.

Referring now to FIGURE 1, reference numeral 1 designates a crude oil distillation zone which may constitute, for example, an atmospheric pipe still or a combination of atmospheric and vacuum distillation towers. Crude oil may be introduced into distillation zone 1 through line 2 and separated in a variety of fractions having different boiling ranges. Light hydrocarbon gases in the C to C range, such as methane, ethane, propane and the like, may be taken off through an overhead line 3. Naphtha may be withdrawn from the distillation zone through an upper side stream withdrawal line such as line 4 and middle distillates such as kerosene and light gas oil may be withdrawn through other lines such as line 5. These middle distillate fractions may boil up to about 900 F. and will be substantially free of metallic contaminants. A heavy gas oil fraction boiling in the range between about 950 F. and about 1300 F. is withdrawn from the lower portion of the distillation zone through line 6.

The residual fraction boiling above the heavy gas oil is taken off as a bottoms product through line 7. Both the residual fraction and the heavy gas oil may be passed directly to the demetallizing process. It is obviously desirable to treat each of these streams separately whenever a specific feed stock is desired. Furthermore, if desired, this crude distillation may be simplified so that only alight fraction boiling below about 250-400" F. is taken overhead and the topped crude is submitted to the HF treatment.

High boiling oil withdrawn either through line 6 or 7 is now passed directly to mixing zone 1%. T he latter may be provided with suitable means for contacting and heating; jacketing or other means are provided for maintaining the temperature within the mixing zone at the desired level. Only a moderate degree of agitation is necessary and indeed desirable.

The dernetallizing step of the present inventive combination involves maintenance of very critical conditions, particularly of temperature and residence time of the feed with the HF at these conditions.

Th mixed HF and feed streams are passed to the reaction zone consisting of a heating coil 11 and soaking drum 12 to give the desired conditions of contact time and temperature. Conditions in the reaction zone are carefully maintained in order to get the desired degree of demetallization without product degradation. These conditions are somewhat dependent on the amount of water present in the recycle HF stream. The amount of water in the HF is kept at less than 10% and perfera'bly less than 5% or lower by adding anhydrous HP from makeup or from fractional distillation of a side stream of the recycle HF. The presence of some water with the HF is beneficial in the metals removal step but excess water decreases the solvent power of the HF in the subsequent extraction step. Pressure is also maintained on the reaction zone (and subsequent extraction zone) to keep the HF in a liquid state, e.g., 15 to 1000 p.s.i. g., preferably 200 to 500 p.s.i.g. Thus using HF of greater than concentration, conditions in the reaction zone are maintained between 200 and 400 F., preferably between 250 and 375 F., for a residence time of between 10 and minutes. Time and temperature are inversely related in part so that shorter times at higher temperatures give about the same metals removal as longer times at low-er temperature. There are, however, limitations to this time and temperature relationship. Below about 200 F., metal removal is very slow and after holding times for reasonable operations (two hours or less) only a moderate degree of metals removal is obtainable. As shown in FIGURE 2, at 250 F. a holding time of greater than 20 minutes is required to get 80% metals removal and after two hours metals removal of less than 90% is eifected. In contrast, a treat temperature of F. gives only about 35% metals removal after an hour with further contact periods providing little incremental metals reduction. This illustrates the ineffectiveness of temperature below 200 F.

Temperatures above 250 F. are preferred in order to give rapid metals removal to the low levels desired. Such conditions of higher temperatures and short contact time are further desirable in order to minimize product degradation as illustrated in FIGURE 3 for modified naphtha insolubles (MNI) increase in the product. Thus short periods of time at temperatures from 300 to 350 F. give less product degradation than longer periods of time required at lower temperatures to give the same degree the same degree of metals removal. Also, with acid concentrations sufficient to give good metals removal, i.e., 95% HF, cracking (with resulting loss of product, coke or tar make, acid consumption, etc.) becomes rapid at temperatures above 400 F. so that even short contact times of a few minutes at these conditions are not practical.

Thus, conditions in the reaction zone necessary for giving the desired results are found to be quite critical, i.e., between 200 and 400 F. and preferably between 250 and 375 F. with contact times between 5 and 100 minutes, preferably between and 60 minutes, using HF acid of greater than 90% and preferably greater than 95% HF. The ratio of acid to feed is not found to be very critical within the range of 5 to 100 wt. percent HF on oil and satisfactory results are readily obtained with 10 to 50 wt. percent HF.

Turning to FIGURE 1 again, liquid hydrofluoric acid, in concentration of greater than 90% but preferably greater than 95% HF, is introduced into zone 10 from acid storage zone 14 through line 15 and mixed with oil. The ratio of acid to oil, i.e. the acid dosage, is determined by the demetallizing conditions set forth above, and may be 5 to 100% by weight, preferably 10 to 50% of oil.

After contacting of oil and HP in the reaction zone under demetallizing conditions of temperature and contact time, the mixture is passed to extraction tower 17 via line 16. A stream of light hydrocarbons boiling in the C -C range, such as butane, is mixed with the product stream via line 13. Preferably about 0.5 to 6 volumes of hydrocarbon, depending on the composition of the residuum feed, is added. The light hydrocarbons serve the purpose of affording better phase separation in tower l7 and also cool the oil-acid mixture to 80 to 200 F., preferably to 120 to 150 F. Alternatively, line 13 may lead into the bottom of tower 17. Under these conditions, in extraction tower I7 (which may be provided with liquid-liquid contacting means such as plates, baffles, packing, etc.), phase separation occurs. At the lower temperature prevailing in this zone, there is no significant reaction of HF with constituents in the oil to form coke, sludge, or Conradson carbon.

The upper layer or raffinate formed in extractor 17 consists essentially of the more paraflinic constituents of the feed, together with most of the hydrocarbon diluent and some dissolved hydrogen fluoride. It is extremely low in sulfur, nitrogen and metal contaminants, as well as asphaltenes, aromatics and Conradson carbon constituents. This deasphalted oil is passed overhead from tower 17 via line 21 to stripping tower 3.9, which is operated at reduced pressures of about 10 to p.s.i.g. and temperatures of 200 to 400 F. to separate the hydrocarbon diluent and residual HF. A stripping gas, preferably the same as or similar to the diluent, may be admitted through line 20. The HF and hydrocarbon from tower 19 are condensed and separated in settler 23. The light hydrocarbon is removed as upper layer and the HF as lower layer and both recycled to the process.

The paraflinic raflinate withdrawn as the bottoms fraction from tower I9 is substantially metal-free. However, it may be desirable to add a final filtration step or water wa-sln ng step or both to this product in vessel 27. An excellent catalytic cracking feed stock is thus obtained.

Returning now to extraction vessel 17, the extract, or lower layer, contains the bulk of the added HF as well as the asphaltenes, Conradson carbon, sulfur, nitrogen, and aromatic feed constituents in solution.

,Verted organic metal components.

It is a peculiarity of the process of the present invention, and a measure of the specificity of the reagent at the demetallizing conditions applied in the reaction zone, that the metal contaminants are present as solid insoluble precipitates, and indeed as salts, rather than as sludges or acid-soluble salts or compounds. In the extraction step these metal salts are dispersed and suspended in the extract phase, and are substantially the only insoluble material thereof.

The extract phase also contains most of the HF and the feed Conradson carbon components, polynuclear aromatics, nitrogen and sulfur components, and any uncon- It is passed via line 28 to stripper tower 30 where under conditions similar to tower 19, e.g. 200 to 400 F. fractionation, it is freed of HF and any light hydrocarbons. A stripping gas, preferably the same as or similar to the diluent, may be admitted via line 29. The bottoms material is then passed via line 31 to filter 32 to remove metal solids of mostly inorganic fluorides (nickel, vanadium, etc.), a polynuclear aromatic-rich product being recovered via line 33. HF and any light fractions contained in the extract are taken overhead via line 34. Normally, this stream is then recycled to separator 23 for separate recovery of HF and paraflin fractions.

The process of the present invention may be subjected to many modifications and variations. Thus the separation of metals from the oil may be accomplished by centrifugation instead of filtration. The oil may be water washed and/or caustic treated to insure complete acid removal. While the reaction zone has been indicated to be a combination of heater and soaker, obviously any appanatus (or combination thereof) which will give the temperature and residence time conditions found critical for effective demetallization can be employed.

Under certain circumstances it may be desirable to treat whole crude rather than residua. In this case, the parafiinic diluent could be dispensed with, at least in part.

- Prefl-ashed total crude is treated with HF under the conditions already described. It is important to remove water prior to this treatment. Residence in the HF extraction tower is about 10 to 15 minutes, with the raffinate and small amount of HF being removed as the overhead stream. This fraction is handled in a manner similar to that described in connection with the previously described embodiment. Lighter components in the crude serve to aid in stripping the HF and are recovered as was the diluent in the previous desorption. The aromatic extract plus most of the HF and substantially all of the metal is removed as a bottoms stream from the HF extraction tower and further processed in a similar man her as previously described with the exception of the diluent recovery step.

The by-product of metallic salts and compounds recovered from the feed stocks may be advantageously employed as a source for the pure metals. In particular, crude oil is an excellent source for vanadium metal. Some crudes, such as Bachaquero, have a very high vanadium content, of the order of 0.04%. The metals recovered in accordance with the process of the present invention are substantially free of the contaminants that usually complicate vanadium recovery from ores. The vanadium fluorides may be converted readily to the sulfate, if desired, roasted with sodium chloride at about 1475 F. to form sodium vanadate, and then converted to V 0 In general, the metals concentrate may be processed by conventional metallurgical techniques and fluorine present recovered by heating with sulfuric acids.

The process of the present invention may be further illustrated by the following specific examples.

The critical conditions that must be maintained in the demetallization reactor to obtain substantially complete metals removal without product degradation are shown in Example 1 below.

III

1 EXAMPLE 1 relation of demetallization and product degradation for reaction of HF with petroleum residua are shown in the following experiments carried out with a 400 F. plus B'achaqnero crude. These experiments were carried out by contacting the Bachaquero topped crude (15.2" API gravity, 400 p.p.m. V, 8.0 Modified Naphtha Insolubles- MNI) with 50 to 77 wt. percent of cylinder hydrogen fluoride 99% HP) in a stirred monel autoclave. Hydrogen fluoride was added in one increment to the heated oil to give the temperature indicated at time zero and samples of the well-stirred mixture were withdrawn at the average times indicated. Inspections for vanadium and MNI on the product obtained after flashing the HF and filtering are shown below.

Experiment 1, 185 F., 0.5 HF/oil:

Time, min 30 60 Filtered product:

P.p.m. V (percent remaining) MN I, wt. percent (percent Inc.)

Experiment 2, 250 F., 0.8 HF/oil:

Time, min 14 32 124 Filtered product:

P.p.rn. V (percent remaining) MNI, wt. percent (percent Inc.)

Experiment 3, 330 F., 0.8 HF/oil:

Time, min 11 39 63 Filtered product:

P.p.m. V (percent remainin MNI, wt. percent (percent Inc.)

These results are further shown graphically in FIG- URES 2 and 3. It is thus obvious from FIGURE 2 showing the percent of metals remaining with time that temperatures above 200 F. and indeed preferably above 250 F. are needed to allow a good degree of metals reduction (i.e. above 80% and preferably above 90% removal) with reasonable contact times (i.e. less than 30 to 60 minutes contact times). Even beyond the advantage of short contact times for reasons of processing to allow higher feed rates and/ or smaller sized equipment, short contact times at higher temperatures are desirable from the standpoint of product degradation as indicated by MNI shown in FIGURE 3. Below 200 F. there is negligible product degradation but metals removal is very slow and ineffective. At about 250 F., metals reduction is fairly rapid, at least to a moderate degree of metals removal, but product degradation is greater than obtained at a higher temperature for a shorter time or even as shown in FIGURE 3 for the same period of time at 330 F. At temperatures above about 375 to 400 F., cracking and other undesired product degradation becomes very rapid as is wellknown (e.g. see U.S. Patents 2,454,615 and 2,527,573). Thus, after obtaining the metals removing reaction at 250 to 400 F., preferably 275375 F., using the minimum time necessary to get the desired metals removal, the temperature is then rapidly reduced to below 200 F. in order to carry out the extraction step with no further product degradation during the settling operations required.

EXAMPLE 2 The following experiments carried out with the same feed and in a similar way as those described in Example 1 illustrate the advantage for using HF containing some water as a means for reducing product degradation. However, metals removal is not reduced when HF of greater than 95% strength is used and metals removal is even en- 5 hanced as also noted in parent application Serial No.

HF strength (percent HF) 90 95 95 Wt. ratio HF/oil 0. 5 0. 5 0. 5 Temperature, F.... 250 250 250 10 Minutes contact 60 60 Filtered product:

P.p.rn. vanadium 73 86 42 Wt. percent MN I 8 8 9 15 EMMPLE 3 Batch hydrofluoric acid deasphalting of West Texas residuum and an atmospheric residuum was carried out. The oil and acid were stirred with approximately 6 volumes of butane for 15 minutes at 250 F. followed by one hour settling at 200 F. prior to withdrawing the raffinate and extract phases. The butane was added since a paraflinic diluent aids phase separation and improves oil yield when HF deasphalting vacuum residua. The rafiinate and extract phases were individually stripped of 29 HF and butane and filtered for metals solids removal. Comparative data for HF de-asph-alted oil and commercial deasphalted oil of equal Conradson carbon level are given below:

Extraction of West Texas residuum 3O Feed Atm.re- Vacuum residuum siduum HF dcmetallization condi- 30 tions:

HF, wt. per wt. oil 1. 0 0. 5 Butanediluent, vol. per 0.5 6

vol. 011 teed. Commercial 03/04 Demetalllzatwn tempera- 250 250 deasphalting with ture, f F. aromatic wash oil Eigti action temperature, 200 200 170-190. Settling time, min so so Feed Raifinate Feed Raffinate Rallinate Oil yield, wt. percent pnfe d 100 74 100 73 55-00 011 yield, vol. percent on feed 100 76 100 76.5 Inspections:

Gravity, API 10.5 23.7 11.0 19.2 18.0 Conradson carbon 5.5 1.8 15.0 4.0 4

Sulfur, wt percent 2.2 1.0 3.3 0.94 1.5 Nitrogen, w

percent 0.34 0.04 0.41 0.15 0.3 Nickel. p.p.rn. 12 1. 0 25 0.5 2 Vanadium,

. 2 2 p p m 4 0 39 0 In all cases, in accordance with the present invention, a significant improvement in gravity, Conradson carbon, sulfur and nitrogen content was achieved in addition to metals removal. The extract material was correspondingly higher in Conradson carbon, sulfur and nitrogen content. However, as the HF converts the major portion of the metals to an inorganic fluoride which can be removed by either filtration -or water washing, the extract after such treatment has a metal content that is lower than the feed.

The present invention resulted in a significant improvement in the reduction in metals content as compared with a commercial deasphalting procedure.

EXAMPLE 4 The necessity of using a light parafiinic diluent with residual stocks, particularly such viscous materials as vacuum resids, is clearly shown by the data in the table below.

Commercial HF/Benzene HF/butane a 4 Process employed Feed HF treat treat treat deasphalting with aromatic wash oil Process conditions:

Temperature, F 250 250 Stirring time, min 15 Settling time, min 60 60 Extracted oil yield, wt. percent. Inspections of extracted fraction:

Gravity, API 11.0 12. 8 11. 3 Conradson carbon, wt. percent 15.0 14.0 2.0 4. 6 4 Sulfur, wt. percent 3. 3 1. 79 1. 95 0. 94 1. 5 Nitrogen, wt. percent 0. 43 0. 69 0.42 0. 15 0.30 Metals, p.p.m.:

Ni 12 4 0. 5 2 39 12 14 O 2 Yield data could not be obtained due to poor phase separation. Inspections were obtained on the fraction recovered that represented the optimum phase separation at the conditions employed.

EXAMPLE 5 Batch hydrofluoric acid treating of Bachaquero atmospheric residuum and West Texas 'atmoshperic residuum diluted with an equal volume of butane were carried out at 350 F., 20 minutes contact time with 10 wt. percent cylinder HF on oil. The treated oil was then cooled to 200 F. and phase separation allowed to occur. Inspections of the raifinate formed under these conditions are hydrodesulfurized before coking or be fed directly to coking operation or utilized in fuel oil sales.

Through the combination of HF treating followed by solvent/HF extraction a superior cracking feed stock is produced. Experimental data are as follows:

Improved catalytic cracking feed stock [South Louisiana gas oil feed] given b610W: P t t t p \I Hi /solvent HFItreating re rea men 1 one ex ruction lus iF solvent HF demetalllzatzon/extractz0n of crude fractions p extmtion Feed Bachaquero West Texas at- Rammite y V01- D01- 400 F.+crude mosphericresiduum 100 90.4 9() 2 o Grav1ty,- 20.9 23.9 24.2 Con. C, wt. percent 1. 0.92 0.58 P TING DITI N y t. per t 0. 16 0. 06 S, wt. percent 0.37 0.27 0. 24 Demetallization step: V, D-IJ-II1- 0.6 0. 2 0. 2 HF, Wt. percent of0i1- 1o 10 D-p- 0. 0 0. 2 02 Butane diluent, vol. per t C 996 1. 4882 1. 4582 vol. of oil feed 1 1 Yi l vol. percent extract 9.6 9,8 Temperature, F. 350 350 Grav y. A I 6. 9 6. 8 C t ti i 20 20 Con. carbon, wt. percent. 10.5 14. 2 Extraction Step; Sulfur, wt. percent 0. 96 1. 21

'glemperature, F 230 Zgg t1- t' i 0 mg m n w l litracted with 0.1 wt. HF on oil with one volume of N-pentanc at a) 2 Treated with 0.1 wt. HF on oil with one volume of pentane at 350 F. [or about 10 min, lowered temperature to 200 F. for phase separation Feed Raffinate Feed Rafiinate or extraction with HF.

Improved catalytic cracking feed Yield, vol perrlcent feed 10g 9 8g 5 i805 0 Gravity A 1 1 Conradson carbon, wt. percent 10. 5 4. 3 5. 5 1. 5 r [West deasphaued 011 r0ed] Sulfur, wt. percent 2. 4 0. 93 00 stars 61o 81% T N 3 2 rea men one pus 5S0 ven pus 1 s0 vent Vanadlum 400 4 0 4 0 extraction extraction I The greatly reduced metals content 0t streams treated Ramnate yield VOL pep 1n accordance with the present invention is clearly shown. ent 100 95. 0 35 gravly, APL t" a on. w .percen EXAMPLE 6 N wtjpercent 0. 24 0.22 0. 0s Sulfur, wt. percent 2. 17 2.05 0.82 In another embodiment of the present invention, heavy p.p.m 2-3 0. 0. virgin gas oils from vacuum distillation and/ or deas- H 0} ha (1 oils from residua ma be contacted with HF p f y b1 b 0 F d 1HF treated at 320 F. with equal weight acid/oil for one hour, removed at e evated temperatures: P era y a ova 3 an HF and then tpentane extracted with3vol. of pentane. troll d o t t tim condifigng may b chosen so 2 HF treate at 350 F. with 0.1 Weight acid/oil for approximately 10 d l C minutes with one volume pentane, cooled oil/acid to 200 Rand extracted the HF Selectlvely convert? a dltlona P to with the 11F phase. The HF phase containcdthe HF converted product radson carbon type material; the treated oil is then d1- p vlrgm Conradson Carbon componentsillifid With a paraffinic diluent and the HF is then used Various modifications may be made 0 {1'15 present as a Solvent to extract h Converted mateflal along process. While the process illustrated in FIGURE 1 is Wlfll the oblectlonable vll'glll components- The normally preferred, other integrated processes employing U011 p 15 earned out at a tempfimtufe of about the present hydrogen fluoride demetallization conditions whereby minimum HF remains in the parafiinic diluted can b employed F example, although not normally HF treated oil. The solvent may be stripped from the d i d h d fl id may b li to h gas oil and the treated gas oil may be fed directly to metallization zone as a Hi /hydrocarbon oil product catalytic cracking. The HF extract phase is freed of stream (acid soluble) recovered from the conversion HF by conventional means and the Conradson carbon of virgin naphthas, distillates or gas oils with hydrogen material containing high sulfur and nitrogen may be fluoride.

That which is sought to be protected is set forth in the following claims.

What is claimed is:

1. A process for removing metallic contaminants from high boiling hydrocarbon fractions which comprises treating said fractions in the liquid phase at a temperature of 200 to 400 F. for to 100 minutes with liquid hydrogen fluoride of at least 90% concentration.

2. The process of claim 1 wherein said high boiling fractions boil at temperatures in excess of 950 F. and contain nickel and vanadium impurities.

3. The process of claim 1 wherein said high boiling fractions are contacted with said hydrogen fluoride at a temperature in the range of 250 to 275 F.

4. A process for removing nickel and vanadium contaminants from a hydrocarbon fraction boiling above 950 P. which comprises contacting said fraction in the liquid phase with concentrated liquid hydrogen fluoride of at least about 90% concentration at a temperature in the range of 200 to 400 E. for 5 to 100 minutes, and thereafter reducing the temperature to less than about 200 F. so as to separate and recover a metals rich extract fraction and a paraflinic low metals content fraction.

5. The process of claim 4 wherein a light hydrocarbon boiling in the C C range is added to the hydrogen fluoride-treated hydrocarbon fraction prior to reducing the temperature thereof to less than 200 F.

6. The process of claim 4 wherein said hydrocarbon fraction is treated for to 60 minutes at 250 to 375 F. with said concentrated hydrogen fluoride.

'7. An integrated process for demetallizing a hydrocarbon oil fraction boiling above 950 F. While obtain ing a paraffinic fraction of low metals content, an aromatic product of reduced metals content, and a metals concentrated fraction which comprises: treating said heavy hydrocarbon fraction in the liquid phase at a temperature of 200 to 400 F. for 5 to 100 minutes with liquid hydrogen fluoride of at least 90% concentration in a reaction zone, contacting said treated fraction with a C C paraffin stream, reducing the temperature of the resulting hydrogen fluoride-treated hydrocarbon stream to less than about 200 F., recovering overhead a paraffinic.

product of reduced metals content, recovering as a bottoms fraction a metals rich fraction, passing at least a portion of said bottomsfraction to a solids removal zone and recovering from said zone an aromatic-rich product of reduced metals concentration, and a metals concentrated fraction.

8. The process of claim 7 wherein the bottoms fraction recovered at a temperature of less than 200 F. is first passed to a flash zone for removal of light hydrocarbons prior to passage to solids removal zone.

9. The process of claim 7 wherein said heavy fraction contains nickel and vanadium, contact between said hydrocarbon oil and said hydrogen fluoride in said reaction zone is maintained at a temperature of 250 to 375 F. for 10 to 60 minutes, and the effluent of said zone is separated into metals-rich and metals-lean fractions at a temperature of about 80 to 200 F.

10. An integrated process for demetalliZin-g a hydrocarbon oil fraction containing consituents boiling above about 950 F. to obtain a paraffinic fraction of reduced metals content and an aromatic product of reduced metals content and precipitated metallic contaminant material which comprises: treating said hydrocarbon fraction at a temperature of 300 to 400 F. for a period of 5 to 100 minutes with liquid hydrofluoric acid of at least 90% concentration at a dosage rate of 5 to 100 wt. percent HF based on oil in a reaction zone, contacting said thus treated fraction with a C to C paraflin stream, reducing the temperature of the resultant hydrogen fluoride treated hydrocarbon stream to less than about 200 F., allowing the mixture to settle into two phases, recovering overhead a paraflinic hydrocarbon fraction containing HF, of reduced metals content, passing said overhead fraction to a zone wherein HF is removed overhead by vaporization, recovering a bottoms aromatic hydrocarbon fraction containing precipitated metal contaminant material, passing said bottoms fraction to a zone wherein HF is removed overhead by vaporization, subsequently passing said HF free aromatic fraction to a solids removal zone and recovering from said zone an aromatic rich fraction of reduced metals concentration and a precipitated solids meal contaminant material.

11. The process of claim 10 wherein the stream of light hydrocarbon boiling in the C to C range is added in an amount of 0.5 to 6 volumes of hydrocarbon to a volume of feed.

12. An integrated process for demetallizing a hydrocarbon oi-l fraction containing constituents boiling above about 950 F. to obtain two hydrocarbon fractions of reduced metals content and precipitated metallic contaminant material which comprises: treating said hydrocarbon fraction at a temperature of 300 to 400 F. for a period of 5 to 100 minutes with liq-uid hydrofluoric acid of at least concentration in a reaction zone, allowing the mixture to settle into two phases, recovering overhead a hydrocarbon fraction containing HF, of reduced metals content, passing said overhead fraction to a zone wherein HP is removed ovrehead by vaporization, prior to the separation of any insoluble materials, recovering a bottoms hydrocarbon fraction containing precipitated metal contaminent material, passing said bottoms fraction to a zone wherein HP is removed overhead by vaporization, prior to the separation of any in soluble materials, and substantially removing from the respective HF free fraction any precipitated solids metal contaminant material.

References Cited by the Examiner UNITED STATES PATENTS DELBERT E. GANTZ, Primary Examiner.

ALPI-IONSO D. SULLIVAN, Examiner.

Claims (1)

1. A PROCESS FOR REMOVING METALLIC CONTAMINANTS FROM HIGH BOILING HYDROCARBON FRACTIONS WHICH COMPRISES TREATING SAID FRACTIONS IN THE LIQUID PHASE AT A TEMPERATURE OF 200* TO 400*F. FOR 5 TO 100 MINUTES WITH LIQUID HYDROGEN FLUORIDE OF AT LEAST 90% CONCENTRATION.

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