Patented Mar. 6, 1951 2,543,995 UNITED STATES PATENT OFFICE 2,543,995 TREATING HYDROCARBON OS Theodore B. Tom, Harmond, Ind., assignor to Standard Oil Company, Chicago, Ill., a corpo ration of Indiana, No Drawing. Application January 27, 1950, Serial No. 140,970 16 Claims. (CI. 196-39) 2 This invention relates to the treatment of light of an organo-arSonic acid having the general hydrocarbon oils and more particularly relates formula, to the stabilization of light petroleum oils which have been Sweetened with a copper compound. XH Hydrocarbon oils, particularly light petroleum oils, such as kerosene, gasoline, naphtha, and simi lar petroleum distillates, usually contain a variety an organo-arsinic acid having the general formula of sulfur compounds, which are undesirable from the viewpoint that they impart an unpleasant X odor and corrosive properties to the petroleum 10 R-As-x oil. A number of methods are employed to re l, move these undesirable Sulfur compounds or to an organo-arsenic acid having the general for convert the sulfur compounds to form which do . mula, not impart undesirable properties to the oil. One XE. of the imethods employed is the so-called copper S Sweetening method wherein the Sour petroleum RX-As-x oil is treated with copper chloride and/or other XH copper salts for the purpose of removing the of an Organo-arsinous acid having the general for fensive Sulfur compounds or converting the Same mula, into a harmless and unobjectionable form. Oils treated with Such copper reagentS are Susceptible As-xH to oxidative deterioration, as evidenced by a marked decrease in the SO-called induction peri R ods, by a loss of color Stability, and by the forma an organo-arsenous acid having the general for tion of gun. 25 mula, It is an object of the present invention to pro XI vide a method of Stabilizing petroleum oils which AS-XRs have been Subjected to treatment With a copper KH containing reagent. Another object of the in and mixtures thereof, in which R, R1, R2, R3, R4 vention is to provide a method of Stabilizing cop 30 and R5 are organo radicals selected from the group per-Sweetened petroleum distillates. A further consisting of aliphatic, cycloaliphatic, aromatic, object of the invention is to provide an improved heterocyclic radicals and mixtures thereof, and method of inhibiting the OXldative deterioration X is at least one element selected from the class of copper-sweetened petroleum distillates. Still consisting of oxygen and sulfur. anotiller object of tine invention ls to provide a 35 The term “organo-radical' as used herein and method of treating copper-Sweetened petroleum in the appended claims includes organo radicals distill lates to remove Linerefrom copper and/or which may contain Substituent groups, such as copper compounds which promote the oxidative for example, oxy, hydroxyl, thio, amino, mercapto, deterioration of Such petroleum distillates. Otner halogen, or other groups. OpJeCUS and advantages of the herein described 40 Specific examples of compounds falling within invention Wiil become apparent as the description the above-named arsenic compounds are the foll thereoI proceeds. lowing: In accordance With the present invention hy Organo arSonic acids, e. g.- drocarpon olls, particularly petroleum olis, Such 45 Benzylar'Sonic acid as gaSone, kerosene, fuel oils, naphthas, and the Butylarsonic acid like, Wnetner obtained from stralignt run or crack Phenylarsonic acid ing proceSSes Which have been Subjected to treat AllylarSonic acid ment With a copper reagent to remove undesirable OctylarSonic acid constituents therefrom or to convert Such unde 50 PhenylthioarSonic acid sirabie constituents to unobjectionable forms, and AllylthioarSonic acid which are normally Susceptible to oxidative de ButylthioarSonic acid terioration because of the presence of copper Cetylarsonic acid and/or copper compounds therein, can be stabi TolylarSOnic acid 55 HydroxyphenylarSOnic acid lized against Such oxidative deterioration by treat Terpenylarsonic acid ment with a water-soluble organo-substituted Ethoxyphenylarsonic acid acid of arsenic selected from the class consisting 3-amyl-4-hydroxyphenyl-arsonic acid, etc. 2,543,995 3 4. Organo thion-arsonic acid, e. g.- organo arsenic compounds for five minutes, the Hexylthion-arSonic acid aqueous phase Separated from the upper layer, Phenylthion-arSonic acid, etc. and the latter filtered. Each of the treated Organo thion-thiol-arSonic acid, e.g- Sweetened Samples was stored under a nitrogen Lauryl thion-thiol-arsonic acid atmosphere until tested. Xylyl thion-thiol-arSonic acid, etc. Table Organo-trithio-arSonic acid, e. g.- Butyl-trithio-arsonic acid Induction Period, Phenyl trithio-arSonic acid, etc. 10 Minutes Organo-monothiol-arSonic acid, e.g.- Stock Phenyl monothiol-arSonic acid A. B C Decyl monothiol-arSonic acid Xylyl monothiol-arsonic acid, etc. Unwashed.------35 248 85 Organo dithiol-arSonic acid, e. g.- 15 Washed with 1% Solution p-OH-phenylarsonic acid------235 675 ------Lauryl dithiol-arSonic acid Washed with 1% Solution alkylarsonic acid--- Washed with 1% Solution n-propylarsonic acid Isoamyl dithiol-arSonic acid Washed with 1% Solution phenylarsonic acid. and similar organo derivatives of arsinic and thio arsinic acid, arsenic and thio-arsenic acid, arsi nous and thio-arsinous acid, arsenous and thio 20 The effectiveness of the organo arsenic Com arsenous acid. While all of the organo arsenic pounds in increasing the oxidation stability of compounds of the above type are effective for the copper chloride Sweetened light petroleum distill herein described purpose, it is not to be implied lates is indicated by the increase in the induction that all are equivalent since the specific gravity period. of the various compounds varies to some extent. 25 The effectiveness of the organo, arsenic acids The treatment with the organo-Substituted acid iri stabilizing copper sweetened light petroleum of arsenic is carried out by contacting the hydro distillates against color and gum forming bodies carbon oil with the oil-immiscible solution of the is illustrated by the data in Table II. These data, organo-Substituted acid of arsenic, at a tempera were obtained by treating. a heater oil having a ture of from about 35° F. to about 210° F., and 30 distillation, range of fron about 340 F. to about preferably from about 60° F. to about 100° F., for 575° F. with a copper chloride clay catalyst and a period Sufficient to remove the objectionable with an organo ai'Senic compound in the manner copper compounds. Usually, contact times of above described and determining the color of the from about 0.5 minute to about 15 minutes will be treated heater. Oil, before and after aging at 200 found sufficient, contact times being dependent F. for twenty hours. The gum reported in Table on the means employed to obtain most intimate IE was obtained, according to A.S.T.M. Method contacts between the immiscible liquids. Solu D-381, modified by the use of preheated steam as tions of from about 0.01% to about 10%, pref a Substitute for air and 500 F. operating tem erably from about 0.5% to about 5.0% concentra perature instead of 320 F. tion can suitably be used in accordance with the 40 present invention. Oil-immiscible solutions of Table II the organo-substituted acids of arsenic are, for example, Solutions of the acid in water, alcohols, After 20, Hrs. Aging e.g. methanol, ethanol, etc., acetone-water mix Original-- at 200°F, tures, glycol-water mixture and other substan $8.5aybolt . 500°F00° F. tially oil-insoluble solvents, S. Steam-Gum, The effectiveness of organo arsenic acids in ning.1100 ml. stabilizing light petroleum oils which have been

Sweetened with a copper compound, is illustrated Unwashed.------12 7 33.6 50 Washed with 1% Solution p-OH by the data in Table I, obtained by subjecting the ptienylal'Sonic Acid------12 1-1/2 1,8 following petroleum distillate to oxidation stabil Washed with 1%, Allylarsonic - - ity tests, as determined by the A.S.T.M. Method Acid------2 -- 3. D-525-46. (A) A cataiytically cracked naphtha, having a While I have described my invention by refer distillation range of from about 155° F. to about 55 ence to specific embodiments thereof, the inven 400°F., Sweetened by vigorously stirring and bub tion is not to be limited thereby, but includes bling oxygen through a slurry of one liter of the within its scope such modifications aS come with naphtha and 8 grams of copper chloride-clay in the spirit of the appended claims. catalyst, consisting of 72% Attapulgus clay fines, 1. The method of stabilizing a copper-contam 8% Copper chloride and 20% water for 30 min 60 inated hydrocarbon oil comprising mixing Said utes, and filtering. oil with an oil-immiscible solution of an organo (B) A thermally cracked naphtha, having a substituted acid of arsenic selected from the class distillation range of from about 150 F. to about consisting of an organo arsonic acid having the 385 F., Sweetened in the same manner as sample general formula. A; and (C) A thermally cracked naphtha, having a distillation range of from about 145° F. to about 400°F., Sweetened by contacting the naphtha, with KH the copper-clay catalyst in the presence of oxygen with vigorous stirring for two and one-half hours 70 an organo-arsinic acid having the general for at room temperatureS. mula, Before subjecting each of the above-described copper sweetened naphthas to the oxidation sta R-A sex bility test, 4 parts of each sample were shaken With part of a 1% aqueous Solution of various 75 b.

5 2,548,995 an organo-arsenic acid having the general for 6 Inula, 10. The method of stabilizing a copper-con taining hydrocarbon oil comprising agitating a mixture of Said oil and an aqueous Solution of Organo Substituted arSonic acid having a con v centration of from about 0.01% to about 10% at X a temperature of from about 35 F. to about 20 an organo-arsinous acid having the general for F., permitting the mixture to separate into an mula, aqueous layer and an oil layer, and Separating the aqueous solution from the treated oil. 10 11. The method of stabilizing a light petroleum distillate Sweetened by treatment with a copper R. compound, comprising contacting said copper an organo-arsenous acid having the general for sweetened hydrocarbon petroleum distillate with mula, an aqueous Solution of an organo-Substituted XE 5 arSonic acid of from about 0.01% to about 10% As-x Rs concentration at a temperature of from about 35 F. to about 210° F., and separating the treated kH petroleum distillate from the aqueous solution. and mixtures thereof, in which R, R1, R2, R3, R4 12. The method of claim 11 in which the Or and R5 are organo radicals selected from the 20 gano-Substituted arSonic acid is propylarsonic group consisting of aliphatic, cyclo-aliphatic, aro acid. matic, heterocyclic radicals and mixtures thereof, 13. The method of claim 11 in which the or and X is an element Selected from the group con gano-Substituted arSonic acid is allylarsonic acid. sisting of oxygen and sulfur, and separating the 14. The method of claim 11 in Which the Or oil-immiscible solution from the treated oil. 25 gano-Substituted arSonic acid is a phenylarsonic 2. The method of stabilizing a copper-contami acid. nated hydrocarbon oil comprising agitating a 15. The method of claim 11 in which the Or mixture of said oil and an oil-immiscible Solution gano-Substituted arSonic acid is para-hydroxy of an organo-Substituted arSonic acid and Sepa phenylarSOnic acid. rating the oil-immiscible solution from the treat 30 16. The method of stabilizing a copper chloride ed oil. Sweetened petroleum distillate comprising con 3. The method of claim 2 in which the Organo tacting said copper chloride sweetened petroleum substituted arSonic acid is an aliphatic-Substi distillate With an aqueous solution of an organo tuted arsonic acid. Substituted arsonic acid having a concentration 4. The method of claim 3 in which the ali 35 Within the range of from about 0.01% to about phatic-substituted arsonic acid is propylarsonic 10%, at a temperature of from about 60° F. to acid. about 100 F., and separating the treated petro 5. The method of claim 3 in which the ali leum distillate from the aqueous Solution. phatic-substituted arsonic acid is allylarSonic acid. 40 6. The method of claim 2 in which the Organo THEODOREB. TOM. substituted arsonic acid is an aromatic-Substi REFERENCES CITE) tuted arsonic acid. 7. The method of claim 6 in Which the aro The following references are of record in the matic-substituted arsonic acid is a phenylarsonic file of this patent: acid. UNITED STATES PATENTS 8. The method of claim 6 in which the aro Number Name Date matic-substituted arsonic acid is para-hydroxy 1742,021 Ackerman ------Dec. 31, 1929 phenylarsonic acid. s 2,232,971 Records et al. ------Feb. 25, 1941. 9. The method of claim 2 in which the organo 50 substituted arsonic acid is a cyclo-aliphatic-Sub 2,428,686 Shipley et al. ------Oct. 7, 1947 stituted arsonic acid. 2,436,494 Shipley et al. ------Feb. 24, 1948