US2951033A - Process for preparing stable heating oil - Google Patents

Description

PROCESS FOR PREPARENG STABLE HEATING GIL Richard W. Sauer, Barrington, N.J., and Arthur F. Weed, Wilmington, DeL, assignors to The Atlantic Refining Company, Philadelphia, Pa., a corporation of Pennsylvania No Drawing. Filed Mar. 28, 1958, Ser. No. 724,508

4 Claims. (Cl. 238-226) This invention relates to a process for the production of high quality heating oil blends comprising virgin and catalytically cracked constituents. The invention is more particularly directed to a process for the separate pre-treatment of catalytically cracked heating oil fractions and virgin heating oil fractions whereby they may be etfectively blended to produce a high quality heating oil product which remains stable in storage.

The fuel compositions to which this invention relates are those which are used primarily in oil burners for heating purposes and are generally characterized as heating oils. Heating oils may be derived from petroleum by various methods, including straight distillation from crude petroleum oil and catalytic cracking of various petroleum oil fractions. Suitable fractions of virgin and catalytically cracked components may be blended to obtain a heating oil fraction boiling in the range of about 350 F. to 675 F. It is known, however, that heating oils consisting in part of catalytically cracked components tends to be unstable when stored in contact with air resulting in color degradation and the formation of a deleterious sediment. Moreover, when catalytically cracked heating oil fractions are blended with virgin heating oils the resulting blend may be substantially poorer in quality than either of the components due to their incompatibility. Consequently, the sediment in the blended oils may cause valves or filters to clog, or otherwise cause the burner systems to mal function.

It is known that catalytically cracked heating oils contain aromatic mercaptans such as thiophenols, thiocresols and thioxylenols'. It is also known that virgin heating oils contain aliphatic mercaptans. It has been established that aromatic mercaptans play an important role in sediment formation and color degradation, but the effect of aliphatic mercaptans has not been established. The exact nature of the sediment and the mechanism by which it is formed have not been determined heretofore, although they have been a subject of study for some time.

Various methods have been proposed to preclude sediment formation and color degradation in order to attain compatible blends of virgin and catalytically cracked heating oil stocks. It is standard refinery practice to treat a blend of virgin and catalytically cracked heating oil constituents with a dilute caustic alkali solution, for example 5 percent NaOl-I, in order to remove mercaptans therefrom. This practice is ineffective in that only a portion of the aromatic mercaptans are removed from the blend while none of the aliphatic mercaptans are removed. Consequently it is usually necessary to use dispersing additives or sediment inhibitors in order to obtain a stable blend.

It has been proposed to remove mercaptans by hydrogenating the combined pool of virgin and catalytically cracked stocks. This procedure, however, is costly when applied to the total pool. It has also been proposed to v tent C treat the catalytically cracked constituent separately with dilute caustic solution, but this too is ineffective in removing entirely the aromatic mercaptans from the catalytically cracked component and does not, by itself, render the subsequent blends of virgin and catalytically cracked constituents compatible.

Various procedures have been proposed for the separate treatment of the virgin constituent of heating oils. Caustic treatment of the virgin fraction fails to remove aliphatic mercaptans. Sweetening processes, for example, hypochlorite treating, doctor sweetening and copper treating are likewise ineflective. Although causticmethanol treatment removes mercaptans from naphtha and gasoline fractions it fails to remove higher molecular Weight mercaptans present in the higher boiling heating oil fraction. Cresolate treating or treatment with sodium salts of isobutyric acid and caustic serve to increase the solubility of the aliphatic mercaptans in the caustic solvent but, like the caustic-methanol treatment, do not completely remove the mercaptans.

It is, therefore, an object of this invention to produce compatible heating oil blends from catalytically cracked and virgin constituents which remain stable in storage without sediment formation and without color degradation.

It is another object of this invention to produce high quality heating oil blends from catalytically cracked and virgin constituents by an efficient and economic process.

Other objects and advantages will be apparent from a reading of the specification and the appended claims.

It is now theorized that sediment formation in heating ils containing catalytically cracked stocks is due to oxidation of heating oil components by oxygen in air, catalyzed by aromatic and aliphatic thiols, and condensation of the oxidized components through ester linkages. Decarboxylation of the sediment by pyrolysis showed the presence of (a) hydrocarbons, such as benzenes, tetralins, naphthalenes, diphenyls, and tr-icyclic aromatics, (b) nitrogen compounds, such as pyrroles, indoles, carbazoles, pyridines, and quinolines, and (c) small amounts of sulfur compounds, such as thiophenes and cyclic sulfides. The side-chain oxidation of these reactive hydrocarbons, nitrogen and sulfur compounds present primarily in the catalytic component is catalyzed by aromatic and aliphatic thiols to form hydroperoxides,

catalyzed CHs-ACH2O 0H by thiols on3-A-'orra+0,

wherein A is a hydrocarbon, nitrogen compound, or sulfur compound of the type enumerated above. The hydroperoxides condense to form intermediate complexes,

This is in agreement with the sediment inhibiting eifect which was found for bases in general. When the de- Further oxidation of the initial ester side chains results in forming more ester bonds to yield higher molecular weight products which result in sediment formation and oil soluble color bodies.v

With respect to sediment formation and color "degradationv it is known that catalytically cracked distillates are. much less stable than virgin distillates. It was thought, however, that straight run distillates merely had a diluting effect on the sediment forming tendency of the catalytic component in blends of the two distillates. It has now been discovered that aliphatic thiols present in the virgin component actively contribute to instability in blends with catalytically cracked distillates. In the presence of aromatic thiols and phenols from the catalytic component, however, the adverse eifect of the aliphatic thiols is not apparent. When the aromatic thiols and phenols are removed from the catalytically cracked component by the process of the instant invention, the pronounced effect of the aliphatic thiols in the blended oils is observed. When the virgin component is separately treated by the process of the instant invention and the separately treated components are blended a stable heating oil blend results.

In accordance with the present invention a catalytically cracked heating oil fraction is separately treated with a caustic alkali solution having a concentration of at least 40 weight percent, and preferably from about 50 weight percent to about 70 weight percent. Concentrations lower than 40 weight percent are ineffective in completely removing the aromatic mercaptans and thus precluding sediment formation and color degradation. Caustic treatment may be performed at ambient temperatures with caustic solutions having concentrations ranging up to the limit of solubility at these temperatures. If higher concentrations are desired the oil may be processed at elevated temperatures The amount of caustic alkali solution may range from about 2 volume percent to about 20 volume percent, from about 5 volume percent to 15 volume percent being preferred. The term caustic alkali solution in this invention refers to solutions of sodium hydroxide or potassium hydroxide.

The virgin heating oil fraction is separately treated to remove the aliphatic mercaptans therefrom. In accordance with the instant invention, substantially complete removal of aliphatic mercaptans may be accomplished by extraction with a solution of sodium Z-aminoethoxide, by clay desulfurization or by treatment with hydrogen. Hydrogen treatment may be performed by known hydro desulfurization processes, for example, by utilizing a cobalt molybdate-alumi-na type catalyst at an operating temperature of 500 F. to 800 F. and preferably at 650 F. to 750 F. and a pressure below 1000 p.s.i., preferably between 300 and 800 p.s.i. The space velocity may range from 1 to 20 volumes of hydrogen per volume of catalyst per hour. The hydrogen to oil ratio may range from 50 to 5000 cubic feet of hydrogen per barrel of feed. The catalyst may be prepared by impregnating soluble salts of cobalt and molybdenum on an alumina carrier, drying and calcining at about 1000 F. The combined oxides of cobalt and molybdenum may vary from 5 to 20 weight percent and the ratio of cobalt to molybdenum may range from 0.1 to 2. Other known field tanks.

methods of hydrogen treatment which utilize other catalysts, for example oxides of nickel and tungsten, may be used in the instant invention. Clay desulfurization may also be performed by known processes, for example, by treatment with a solid adsorbent material such as clay,

. bauxite or fullers earth at 500 F. to 800 F. and preferably at 700 F. to 750 F. and pressures close to atmospheric pressure, preferably from 50 to 100 psi. Aliphatic mercaptans may also be extracted from the virgin heating oil fraction with a solution of sodium 2-aminoethoxide in Z-amindethanol and 1,2-diaminoethane. The sodium Z-aminoethoxide may range in concentration from about 4 to about 20 weight percent in the combined solvents. Higher concentrations result in viscous solutions with a consequent increase in loss of the treating solu tion. The ratio of 2-aminoethanol to 1,2-diaminoethane may vary from about 1:1 to 1:3. The virgin fraction is treated with about 2 to 20 volume percent of the sodium 2-aminoethoxide solution, about 5 to 15 volume percent being preferred. After separation of the phases the oil is water washed to remove any residual solvent.

The separately treated virgin and catalytically cracked constituents are then blended. Although the blends normally vary from 30 to 70 volume percent of the catalytically cracked constituent to 70 to 30 volume percent of the virgin constituent, the two constituents may be blended in any proportion.

The instant invention may be more fully understood by reference to the following examples which are not intended to limit the invention thereto.

EXAMPLE I Two types of stability tests were run in. the examples which follow. One was an accelerated 24 hour test run with a one liter sample at 212 F. in an atmosphere of oxygen. In the other test, 0.8 liters of oil was stored for one year at F. in an atmosphere of air to simulate ambient storage in the field. Both tests were run in the dark in glass bottles containing iron strips to give an oil volume to metal surface ratio typical of that found in At the end of the storage period suspended material and lacquer deposited on the metal and glass surfaces were measured and reported as sediment. The color of the oil was also measured after test.

Gas oil fractions having a boiling range of 650 F. to 1000 F. were catalytically cracked in a fluidized catalyst process with a commercial silica-alumina cracking catalyst consisting of about 87 weight percent silica and 13 weight percent alumina to give a heating oil fraction boiling in the range of 375 F. to 635 F. An accelerated 24 hour stability test was run on various samples of the untreated cracked distillates in the manner previously described. An ASTM color test was also run on these samples. Other samples of the cracked distillates were treated with 10 volume percent of a 50 weight percent sodium hydroxide solution at room temperature. One sample was treated with 10 volume percent of a 50 weight percent potassium hydroxide solution at room temperature. An accelerated stability test and ASTM color test were also run on these samples. The results are set out in Table I.

In a separate experiment, an untreated sample of a catalytically cracked heating oil was stored for one year at 85 F. as described heretofore. Another sample of the same distillate was treated with 10 volume percent of 50 weight percent sodium hydroxide at room temperature. To a third sample of the same distillate, treated similarly with sodium hydroxide, there was added 5.2 mg. of

sulfur as p-toluene thiol per ml. of oil. The three ,samples were stored for one year at 85 F. The amount moved by treatment with strong caustic solution to yield a relatively stable distillate. The addition of 5.2 mg.

Table I EFFECT OF EXTRACTION \VITH 50% CAUSTIC ON THE STABILITY OF CATALYTICALLY CRACKED DISTIL LATES212 F.

Raw 60% Caustic Wash ASTM ASTM Sample Sediment Color Sample Sediment Color (mg/1.) After (mg/1.) After Test Test 76 5% B 6 236+ 74 6+ C 4 2% 128 6- D 9 2% 86 5+ E 7 2% 112 7+ F 9 2%+ 142 4% G 8 2% 76 6 H 6 2% 175 5% I 6 2 A 127 5% J 7 2 A 118 6% K 6 2 146 6 L 8 2% 106 6% M 7 2%4-1- 151 5% N 7 2% 88 6-- 7 2% 119 P 6 121+ 98 4% Q 4 1 /2 84 5+ R 6 2%+ 106 S 3 Treated with 10 volume percent of 60 weight percent KOH.

Table 11 EFFECT OF EXTRACTION WITH 50% CAUSTIC ON THE STABILITY OF CATALYTICALLY CRACKED DISTIL- LATES-1 YR. STORAGE AT 85 F.

ASTM Color After Test Sample Sediment Raw 50% Caustic Wash 50% Caustic Wash plus 5.2 mg. S/lOO ml. as

p-Toluene Thiol EXAMPLE II of the catalytically cracked distillates and 65 volume percent of the virgin distillates. Accelerated stability tests Table III STABILITY OF BLENDS OF CATALYTIOALLY CRACKED AND STRAIGHT RUN DISTILLATES AT 212 F.

Raw Blend 5% Caustic Washed Blend Crude Source Straight Run Component ASTM ASTM Sediment Color Sediment Color (mg/l.) Alter (mg/1.) After Test Test West Texas Ellenberger 106 3% 89 3% Barbers Hill" 45 3% 3?. 2% SanJoaquin 9 2 5 1% Junta Ad0be 1O 2 6 1% Iraq 23 2% 20 2% Kuwait--- 8 1% 10 2 0ficino 12 West Texas Devonian 53 West TexasPermian. 15 Ruiz 22 and ASTM color tests were run on the raw blends. Several samples of the same blends were treated with 10 volume percent of 5 weight percent sodium hydroxide solutions at room temperature. Accelerated stability tests and ASTM color tests were also run on the caustic treated blends. The results are set out in Table III.

The results indicate the instability of untreated raw blends. Comparison with Table I makes it appear that the straight run component merely has a diluting effect on the sediment. Caustic treatment of the blends does not appreciably improve their stability.

EXAMPLE III Untreated samples of catalytically cracked and virgin distillates were blended. The blends contained 35 weight percent of the catalytic distillates and weight percent of the virgin distillates. Varying amounts of aromatic or aliphatic thiols, or both, were added to the samples. Accelerated stability tests and ASTM color tests were run on the samples containing the added thiols as well as on a sample containing no added thiols. The results are set out in Table IV.

Table IV EFFECT OF THIOLS ON THE STABILITY OF A RAW BLEND OF CATALYTICALLY CRACKED AND STRAIGHT RUN DISTILLAIES AI 212 F.

Ooncentra- ASTM Sample Thiol Added tion Thiol Sediment Color Added (mg. (mg/1.) After 5/100 ml.) Test 1- 0.000 14. 4 2 2. 0.77 11.7 2% a- 6. 0 s4. 5 3% 4. 7. 7 95. 4 3 5. p-toluene thiol 40. 0 283 6 6.... pentanethiol-1- 6.0 17.0 2 7.--. pentanethiol-1 40.0 12.5 2 8. a-toluene thiol 6.0 10. 5 1%+ 9- a-toluene thiol- 40. 0 8. 2 1%+ l0 6. 0 l5. 2 2 11 23. 6 2%+ 12 peltiane 03:11-11" 40. 0 i 0 p- 0 none io 6.0 13 {or-toluene tgiol 40. e 0

po uene t io 6.0 14 {tert-nonyl thiol 37.0 48 5 These data indicate that the addition of aromatic thiols markedly degraded the stability of the blends while the addition of aliphatic thiols had relatively little effect. A comparison of samples 3, 12, 13 and 14 shows that aliphatic thiols actually appeared to have a slight inhibiting eifect in blends containing added aromatic thiols.

EXAMPLE IV Samples of a catalytically cracked component of the type described in Example I were treated with 10 volume percent of a 50 weight percent sodium hydroxide solution at room temperature. The treated samples were blended with varying amounts of untreated straight run distill-ates from different crude sources. The aliphatic thiol content of the straight run distillates were determined. Accelerated stability tests and ASTM color tests were run on the blends. The results are set out in Table V.

The results indicate that although aromatic thiols are removed from the catalytically cracked distillates by treatment with strong caustic solution, when the catalytically cracked distillates are blended with untreated straight run distillates stable blends do not necessarily result. The straight run distillates giving poor blending stability were those with a high aliphatic thiol content. These data, when compared to the data in Table I, prove that the straight run component has a pronounced detrimental effect rather than a mere diluting eitect in blends from which aromatic thiols have been removed.

.AROMATIC THIOLS FROM CATALYTIC COD/IPONENT WITH 50% CAUSTIC Straight Run Component Vol. Sedi- ASTM Percent ment Color Aliphatic St. Run (mg/1.) After Crude Source Thiol in Blend Test Content (mg. S; 100 ml.

37 31 95 37 so 78 4% 37 65 68 3% 37 85 37 2+ 60 50 57 1%+ 60 65 48 3% 60 85 20 3% 11 35 38 3 11 50 37 2% 11 65 6 1% 11 80 4 1% 1. 4 36 13 2% 1. 4 50 13 2M?!- 1. 4 65 13 2y.+ 1. 4 80 12 2 0. 4 65 8 254 0. 5 65 6 1% 0. 8 55 8 1% EXAMPLE V per volume of feed per hour. Aliphatic thiols'were removed from other samples of virgin distillates by extraction with 5 volume per cent of an 1132 weight percent solution of sodium Z-aminoethoxide in Z aminoethanol and 1,2-diaminoethane. The sodium Z-aminoethoxide solution contained 117 g. sodium Q-aminoethoxide, 308 g. Z-aminoethanol and 617 g. 1,2-diaminoethane. Y

The separately treated heating oil constituents were blended in varying amounts. Accelerated stability tests and ASTM color tests were run on the blends. The results are set out in Table VI.

Table VI EFFECT ON BLEND STABILITY AT 212 F. OF REMOVING AROMAIIC THIOLS FROM THE CATALYTIC COMPO- NENT AND ALIPHATIC THIOLS FROM THE STRAIGHT RUN COMPONENT Straight Run Component 1 Cata- ASTM lytlc 1 Sedi- Color Compo Vol. ment After nent Crude Source Percent (mg. per Test in Blend 1.)

West Texas Ellenberger (1). 60 8 1% West Texas Ellenberger (1). 65 6 2- West Texas Ellenberger (1). 65 7 154+ West Texas Ellcnberger (2g. 60 5 1% West Texas Ellenberger (2 60 5 1% West Texas Ellenberger (3). 65 7 1% West Texas Ellenberger (4). 65 9 Its-\- raq 65 7 1 /4+ Barbers Hill 65 7 1% West Texas Devonian. 65 9 1% Barbers Hill L- 50 5 192+ Barbers Hill 50 4 1r2+ 1 Letters and numbers signify difierent samples of the catalytic and straight run distillates respectively.

- I Aliphatic thiols removed by treatment with hydrogen. Aliphatic thiols removed from all other straight run samples by extraction with sodium 2-am1noethoxide Solution,

These data prove that separate treatment of the cata lytically cracked and virgin components in accordance with the process of the instantinvention results in stable heating oil blends.

' EXAMPLE VI A sample of an untreated catalytically cracked distillate, obtained in the manner described in Example I, was blended with a sample of an untreated virgin distiflate. Another blend was made with two similar samples and this blend was treated with 10 volume percent of a 5 weight percent sodium hydroxide solution. A third sample of the catalytically cracked distillate was treated with 10 volume percent of a weight percent sodium hydroxide solution and blended with a sample of virgin distillate which had been pre-treated with 10 volume percent of a 5 weight percent sodium hydroxide solution. A fourth sample of the cracked distillate was treated with 10 volume percent of a 50 weight percent NaOH solution and blended with a sample of virgin distillate previously treated with 5 volume percent of a solution of sodium Z-aminoethoxide prepared as in Example V. All blends consisted of 40 volume percent of the cracked distillate and volume percent of the virgin distillate. The blends were stored at 85 F. for 12 months as described heretofore. The aromatic and aliphatic thiol content of each blend, the amount of sediment formed, and the ASTM colors are set out in Table VII.

I Table VII Samples 1 and 2 demonstrate the instability of a blend 0 of untreated heating oil constituents as well as the ineffectiveness of caustic treating the blend. Sample 3 indicates the ineffectiveness of treating the virgin constituent with a weak caustic solution even though the aromatic 'mercaptans are removed from the cracked constituent with strong caustic. of the instant invention by a long term stability test of a heating oil blend made by the process of the instant invention.

EXAMPLE VII Samples of a catalytically cracked distillate obtained in the manner described in Example I were treated with 10 volume percent of a 50 weight percent solution of sodium hydroxide. Several treated samples were blended with untreated samples of virgin distillate. Other treated samples of cracked distillate were blended with samples of virgin distillate from various crude sources previously treated with 10 volume percent of 5 weight percent sodium hydroxide solution. Accelerated stability tests and ASTM color tests were run on the blends. The results are set out in Table VIII.

These data show that unstable blends result when raw virgin distillates are blended with cracked distillates from .which aromatic mercaptaus have been removed by strong Sample 4 demonstrates the utility Table VIII EFFECT ON BLEND STABILITY AT 212 F. F 50% CAUSTIC TREATMENT OF CATALYTIC COMPONENT AND CAUSTIC TREATMENT OI VIRGIN COMPONENT Virgin Component 5% Caustic Treated Virgin Component Raw Virgin Component Sediment Sediment Vol. Plus ASTM Plus ASTM Crude Percent Lacquer Color Lacquer Color (mg/100 (mg/100 ml.) ml.)

Webster 65 64 3l+ 66 3% Barbers HilL. 65 35 3% 24 2% Do 50 34 3% 19 2% West Texas Ellenbergen- 65 19 2% 34 3 West Texas Devonian 65 39 3 39 2 /3- EXAMPLE VIII A catalytically cracked distillate, obtained in the manner described in Example I, was blended with Ultrasene, a commercially highly refined kerosene which simulates a virgin distillate but from which sulfur compounds have been removed. A second sample of cracked distillate was treated with volume percent of a 50 weight percent NaOH solution and similarly blended with Ultrasene. A third and fourth sample were prepared in the same manner as sample No. 2. An alpihatic thiol mixture containing equal amounts of dodecanethiol-l and t-octylthiol was added to sample Nos. 3 and 4 so that they contained 10 mg. of sulfur/100 ml. of the blend and 40 mg. of sulfur/ 100 ml. of the blend respectively. All blends consisted of equal amounts of cracked distillate and Ultrasene. The blends were stored for 12 months at 85 F. as heretofore described. The results are set out in Table IX.

Table IX EFFECT OF ALIPHATIC THIOLS ON BLEND STABILITY-12 MO. AT 85 F.

Thiol Content (mg. 8/100 ml.) Sedi- ASTM Sam- 505O Blend Cat. Inent Color ple Distillate and Ultra- (mg. After sene Aro- Aliper 1.) 12 mo.

matic phatic 1 Raw Cat. Distillate 0.8 None 21 2%+ plus Ultrasene. 2 50% Caustic 0. 05 None 2 1%.-

Treated Cat. Distillate plus Ultrasene. 3 50% Caustic 0. 05 10 70 3% Treated Cat. Distillate plus Ultrasene plus Aliphatic Thiols. 4 Caustic 0. 05 40 106 5% Treated Cat. Distillate plus Ultrasene plus Aliphatic Thiols.

These results demonstrate the adverse effect of aliphatic thiols on blend stability. Sample 2 shows the improvement in blend stability when the aromatic thiols are removed from the cracked distillate. The detrimental effect on the blend stability of increasing amounts of aliphatic thiols are shown by the results obtained with samples 3 and 4.

EXAMPLE IX An untreated sample of catalytically cracked distillate, obtained in the manner described in Example I, was blended with a sample of a virgin distillate which was previously clay desulfurized by passage through clay at 700 F. to 756W". and 50 psi. pressure. A second similar blend was made and the blend was treated with 10 volume percent of a 5 weight percent sodium hydroxide solution. A third sample of catalytically cracked distillate was treated with 10 volume percent of a 50 Weight percent sodium hydroxide solution and blended with a sample of virgin distillate which was previously cl-ay desulfurized. A fourth sample of cracked distillate was similarly treated with a 50 weight percent caustic solution and blended with a sample of virgin distillate previously treated with a solution of sodium 2-aminoethoxide as described in Example V. A fifth sample of cracked distillate was treated with 50 weight percent sodium hydroxide and blended with a virgin distillate which was previously treated with 5 volume percent of a cresolate solution. The cresolate solution was prepared by dissolving 84 grams of purified cresols, recovered from a Unisol treatment of naphtha, in 500 ml. of 5 weight percent aqueous sodium hydroxide. All blends consisted of equal volumes of cracked distillate and virgin distillate. An accelerated stability test was run on each blend of heating oil. The results are set out in Table X.

Table X Sample Treatment Sediment No. (mg/l.)

1 VirgiuClay Desulfurized. CatalyticUn- 46.6

treated. Virgin-Clay Desulfurized. Total Blend 16.3

Treated With 5% Caustic. 3 VirginClay Desulfurized. Catalytic- 6.2

Treated with 50% Caustic. 4 VirginTreated with Sodium Aminoethox- 3.8 ide. Catalytic-Treated with 50% Caustic. 5 Virgin-Cresclate Treated. Catalytic- 31.3

Treated with 50% Caustic.

These data demonstrate the advantage of separately treating the heating oil components to remove completely the aromatic and aliphatic thiols according to the process of the instant invention compared to treatment of the total blend, treatment of the virgin constitutent only, and cresolate treatment of a virgin distillate combined with caustic treatment of a catalytically cracked distillate.

We claim:

1. A process for the preparation of a stable heating oil blend from a catalytically cracked heating oil fraction and a virgin heating oil fraction which comprises separately treatingthe catalytically cracked fraction to remove aromatic mercaptans therefrom by contacting said fraction with from about 2 to about 20 volume percent of an aqueous caustic alkali solution :having a concentration of at least 40 weight percent, separately treating the virgin fraction to remove aliphatic mercaptans therefrom by contacting said virgin fraction with from about 2 to about 20 volume percent of a solution of sodium Z-aminoethoxide in Z-aminoethanol and 1,2-diaminoethane having a concentration of from about 4 to about 20 weight percent in the combined solvents, the ratio of 2-aminoethano1 to 1,2-diaminoethane ranging from about 1:1 to about 1:3, separating the oil and aqueous phases, water washing the oil phase and blending the treated cracked and virgin fractions.

2. A process for the preparation of a stable heating oil blend from a catalytically cracked heating oil fraction and a virgin heating oil fraction which comprises separately treating the catalytically cracked fraction to remove aromatic mercaptans therefrom by contacting said fraction with from about 5 to about 15 volume percent of an aqueous caustic alkali solution having a concentration of from about 50 to about 70 weight percent, separately treating the virgin fraction to remove aliphatic mercaptans therefrom by contacting said virgin fraction with from about 5 to about 15 volume percent of a solution of sodium 2-aminoethoxide in Z-aminoethanol and 1,2-diaminoethane having a concentration of from about 4 to about 20 weight percent in the combined solvents, the ratio of 2-aminoethanol to 1,2-diaminoethane ranging from about 1:1 to about 1:3, separating the oil and aqueous phases, water washing the oil phase and blending the treated cracked and virgin fractions.

1 l 1 2 3. The process according to claim 2 wherein the caustic 1,805,444 Wilson May 12, 1931 alkali is sodium hydroxide. 1,902,221 Day Mar. 21, 1933 4. The process according to claim 2 wherein the caus- 2,287,118 Mottalu June 23, 1942 tic alkali is potassium hydroxide. 2,525,153 McClennan et a1 Oct. 10, 1950 5 2,592,383 Blatz Apr. 8, 1952 References Cited in the file of this patent 82,22; glli el:1 1- -SA 1g- 31, 1954 2, 'car s et a. ept. 13, 1955 UNITED STATES PATENTS 2,717,857 Bronson et a1. Sept. 13, 1955 1,784,262 Wheeler et a1. Dec. 9, 1930 2,719,105 Peterson et a1. Sept. 27, 1955 UNITED STATES PATENT OFFICE CERTIFICATE OF CORRECTION Patent Nos 2,951 o33 A ust so, 1960 Richard We Sauer et ale 7 It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction and that the said Letters Patent should read as corrected below.

Column 1-, line 34L for "tends" read tend column" 9, line 23, for "commercially" read commerclal oolnmn 1O. line 25 Table X, third column thereof, under the heading "Sediment (mg/l,)"- line 1 for "4606 read 4566 line 3:6 for "constitutent read constituent "s Signed and sealed this 4th day of April 1961,

(SEAL) Atte ERNEST W. SWIDER XkXPQQX ARTHUR w. CROCKER Attesting Officer Acting Commissioner of Patents

Claims (1)

1. A PROCESS FOR THE PREPARATION OF A STABLE HEATING OIL BLEND FROM A CATALYTICALLY CRACKED HEATING OIL FRACTION AND A VIRGIN HEATING OIL FRACTION WHICH COMPRISES SEPARATELY TREATING THE CATALYTICALLY CRACKED FRACTION TO REMOVE AROMATIC MERCAPTANS THEREFROM BY CONTACTING SAID FRACTION WITH FROM ABOUT 2 TO ABOUT 20 VOLUME PERCENT OF AN AQUEOUS CAUSTIC ALKALI SOLUTION HAVING A CONCENTRATION OF AT LEAST 40 WEIGHT PERCENT, SEPARATELY TREATING THE VIRIN FRACTION TO REMOVE ALIPHATIC MERCAPTANS THEREFROM BY CONTACTING SAID VIRGIN FRACTION WITH FROM ABOUT 2 TO ABOUT 20 VOLUMEN PERCENT OF A SOLUTION OF SODIUM 2-AMINOETHOXIDE IN 2-AMINOETHANOL AND 1,2-DIAMINOETHANE HAVING A CONCENTRATION OF FROM ABOUT 4 TO ABOUT 20 WEIGHT PERCENT IN THE COMBINED SOLVENTS, THE RATIO 2-AMINOETHANOL TO 1,2-DIAMINOETHANE RANGING FROM ABOUT 1:1 TO ABOUT 1:3, SEPARATING THE OIL AND AQUEOUS PHASES, WATER WASHING THE OIL PHASE AND BLENDING THE TREATED CRACKED AND VIRGIN FRACTION.