US2219859A - Treatment of motor fuels - Google Patents

Description

Patented Oct. 29, 1940 UNITED, STATES PATENT... OFFICE 2,219,859 TREATMENT or MOTOR FUELS James G. White, Kingsport, Tenn assignor to EastmanKodak Company, Rochester, N. Y., a corporation of New Jersey No Drawing.

storage with loss in such valuable properties'as' light color, low gum content and antiknock value, the deterioration being due principally to oxidation and being accelerated by the photochemical action of light. Straight run gasolines, on the other hand, do not ordinarily have the same undesirable tendency to deteriorate, although blended stocks containing cracked gasoline 'and straight-run gasoline usually show the undesir- -able tendency to deteriorate. Similar fractions of hydrocarbon distillates produced by the distillation of hydrocarbonaceous materials other than petroleum frequently also show a tendency to deteriorate upon storage.

It 'has been found that such deterioration of hydrocarbon motor fuels can be retarded to a greater or lesser degree by incorporating in the motor fuel certain phenols, aminophenols and/or phenylene' diamines. The majority of such inhibitors are solid substances which are not highly soluble in hydrocarbon motor fuels and at best dissolve but slowly in the fuel. Accordingly, it is difllcult to obtain a uniform distribution of the inhibitors in the motor fuels without resorting to time-consuming methods of, violent agitation of the motor fuel stock being treated. Furthermore, where huge quantities of gasolines are being stabilized with such inhibitors on a commercial scale, any methods involving violent. agitation are wholly impractical. v s

It is essential in large scale operations to be able to blend the inhibitors into the motor fuels in a manner which permits a rapid uniform distribution of the inhibitor throughout the motor fuel Any uneven distribution of the inhibitors throughout the treated stock is clearly undesirable.

From the practical standpoint of handling motor fuels during the treatment thereof with inhibitors, it is usually most desirable to feed the inhibitors continuously or. intermittently into a flow of the fuel. However, the aforesaid solid inhibitors do not ordinarily rapidly dissolve and Application March 18, 1939, Serial No. 262,705

mobile solutions of the inhibitors which can be fed into the flow of gasoline.

Among other solvents which have been proposed for this purpose is methyl alcohol. Methyl alcohol is a good solvent for the aforesaid in- 5 hibitors and does not have a seriously deleterious effect on the inhibiting potency of the inhibitors. While methyl alcohol is a good solvent for the inhibitors, itdoes not have an especially good dispersive action on the inhibitors in the 10 gasoline and is not fully satisfactory where water is encountered in the gasoline, such as is ordinarily the case under actual storage conditions. The butyl alcohols are not a particularly good solvent for the aforesaid inhibitors (e. g. the in- 15 hibitors tend to separate from solution at lower temperatures) but have a betterdispersive action on the inhibitors than does methyl alcohol. However, again, the butyl alcohols are notfully satisfactory where water is encountered in the gaso- 20 line.

Ithas been proposed to employ a combination of methyl alcohol and a butyl alcohol as a solvent. However, such a combination, while serving to combine the good solvent powers of the 25 methyl alcohol with the good dispersive action of the butyl alcohols does not avoid the difliculties encountered when dealing with wet gasolines. Furthermore, in order to, arrive at solution which. gives a low cold test (i. e. a solution which does 30 not lose mobility, and from which the inhibitors do not tend to separate at low temperatures), it is necessary to employa major proportion of methyl alcohol in the combination, so that the dispersive action of the butyl alcohols isonly 35 utilizedto a relatively small extent. Isopropyl alcohol is a better solvent than the butyls for the aforesaid inhibitors and has a good dispersive action on the inhibitors in the gasoline. Furthermore; isopropyl alcohol soluo tions are not troublesome when wet gasolines are encountered. However, isopropyl alcohol solutions will not stand low cold tests, i. e. at temperatures of about -40 F., the ispropyl alcohol solutions become troublesomely viscous and there 45 is some -tendency for the inhibitorsto separate from solution.

'I have now found that unlike butyl alcohol. solutions, isopropyl alcohol solutions can be made to withstand low cold tests by incorpora tion therein of, not a major proportion, buta relatively small amount of methyl alcohol, so that they dispersive action of the isopropyl alcohol on, the inhibitors is not greatly depleted. I have further found that ethyl alcohol can be em- 65 Methyl alcohol methyl or ethyl alcohols is employed, and most 10 advantageously, a mixture comprising about 10 to about 20% by volume of methyl alcohol and 'the remainder of isopropyl alcohol is employed. Such solutions readily disperse inv hydrocarbon motor fuels and'have good cold tests.

15 The following examples are offered to illustrate typical solutions which I employ in practicing my invention. These examples are not intended to limit my invention.

Ezamplef 20 e 1 Grams- Isopropyl alcohol 25 Methyl fl1cOhQ1 5 N-monomethyl-p-aminophenol 25 Example II Grams lgopmpyl alnnhnl 25 Methyl alcohol 5 N-monobenzyl-p amin'ophenol 25 Example III Grams lgopropyl alcohol -'25-' Methyl 'nlrnhnl 5 85 N-monobutyl-p-aminophenol 25 Grams Isopropyl alohhnl 25 Ethyl alonhhl 5 N-monbbutyl-p-aminophenoLl- ..s 25

' Example V V Grams- A mixture consisting of about 92% by weight of N-(n-primary-butyD-p-aminophenol and about 8% by weight of N,N'- di (n-primary butyl) p phenylenedi m n 49.3 kopropyl alcohol"; I. 47.9 59 Methyl alcohol 5.3

soon a solution, which contains about -1o%by volume of methyl alcohol and about 90% by vol- -ume of isopropyl alcohol, when cooled to 40 F.

did not crystallize. n the other hand the following prior art solution crystallized atabol t .5- F. Grams a moot. consisting or about 92%by on weight of N-(n-primarybutyl) -p-amino-.

phenol and about 8% by weight of' N,N- di (n primarybutyl) pphenylnedi Ordinarily, I have found it advantageous-to make up the solutions of inhibitors in my new solvents, employing about one part by weight of the inhibitor to one by'weisht'of the solvent.

70 Other ratios of solvent to inhibitor can be employed.

.-8ui1lcient of the solution of the inhibitor should be incorporated in the gasoline to give a concentration of inhibitor in the gasoline which -will substantially retard deterioration of useful and economical concentration of inhibitor will, of course, vary from inhibitor to inhibitor and motor fuel to motor fuel. The most advantaseous concentration 1' inhibitor is, of course, readily determined. y making the ordinary tests and-observatibns customarily em- 10 ployed in the art. a

As phenol inhibitors, which are. especially useful in conjunction withmy new solvent, hydroquinone, diamyl-hydroquinone and catechol may be mentioned; As aminophenolic inhibitors, N-alkyl-p-aminophenols, 'e. g. N-methyl-, N- benzyl-, N-n-primarybutyl, N-isobutyl-, N-isoamyl-, N-n-primary myl, N-hexyl-, N-heptyl-, N-octyl-,-and N-cetyl-p-aminophenols, are especially useful in conjunction with my new solvent.- As phenylenediamine inhibitors, N,N'-dialkyi-p phenylenediamines, e. g. N,N'-di-(n-pri-.

marybutyl) and ,N,N-diisoamyl-p-phenylenediamines, are especially useful in conjunction with my new solvent. Mixtures of N'-alkyl-p-amino- 5 phenols and N,N'-dialkyl-l='-phenylenediamines, particularly those containing a majority of N-alkyl-p-aminophenols, are especially'useful iri conjunction with my new solvents. Mixtures of o N-alkyl-p aminophenols and. N,N'-dialkyl-pphenylenediamine are described for example in J,

the copending application of Harold Von Bramer and Albert C. Ruggles, Serial No. 96.467, filed August 1'7, 1936 (now U. S. Patent No. 2,163,640, dated June 2'7, 1939). Y What I claim asmy invention and desire to be secured by Letters Patent of the United line comprising a solution of an inhibitor 08138.-

ble of inhibiting deterioration of cracked gasoline selected from the group consisting of phenols, aminophenols and phenylenediamines, the solvent of said solution comprising not more than about 20 by volume of an'alcohol selected from the group consisting of methyl and ethyl alcohols and at-least about 80% by volume of iso-'- propyl alcohol.

3. A deterioration inhibitor for a cracked gasoiine comprising a solution of an inhibitor capa- 6o ble of inhibitingdeterioration of cracked gasoline selected from the group consisting of phenol, amino phenol and 'phenylenediamine inhibi-' tors, the solvent of said solution comprisingnot more than about 20% by volume ofmethyl alcoholjand-at least about by volume of isopropyl alcohol. l

4. A deterioration inhibitor for cracked gasoline comprising a solutionof a N-alkyl-p-aminophenol inhibitor the solvent of said solution '70 phenylenediamine inhibitor, the solvent of said solution comprising about 16 to 20% by volume of methyl alcohol and about 90 to about 80% by volume or isopropyl alcohol.

6. A deterioration inhibitor for a cracked gasoline comprising a solution of a N-alkyl-p-amino-phenol capable of inhibiting. deterioration of cracked gasoline and'in which aminophenol the alkyl group contains at least four carbon atoms,

proportion, based on the and a substantial amount of the aminophenol, of a N,N'-dia1kylp-phenylenediamine in which each alkyl group contains at least four carbon atoms, the solvent or said solution comprising about 10 to 20% by volume of methyl alcohol and from about 90 to about 80% by volume of isopropyl alcohol.

'7. A method for stabilizing cracked gasoline against deterioration which comprises adding to the gasoline a solution of an inhibitor capable of inhibiting deterioration'of hydrocarbon motor fuels and selected from the group. consisting of phenols, aminophenols and phenylenediamines, the solvent of said solution comprising not more than about 20% by volume of-an alco- 10 hol selected from the group consisting of methyl and ethyl alcohols, and at least 80% by volume of isopropyl alcohol. 7

JAMES 6. WHITE.