WO1990006982A1

WO1990006982A1 - Fuel stabilizer composition

Info

Publication number: WO1990006982A1
Application number: PCT/US1989/005411
Authority: WO
Inventors: Paul C. Naegely
Original assignee: The Lubrizol Corporation
Priority date: 1988-12-21
Filing date: 1989-11-30
Publication date: 1990-06-28
Also published as: IL92778A0; BR8907269A; ZA899838B; CN1044118A; AU4748890A; JPH03502819A; EP0403624A1; CA2005707A1; ES2018123A6

Abstract

The present invention deals with minimizing color formation in middle distillate fuel oils by treating the fuel oil with an aromatic hydroxyl containing compound which is hydrocarbyl substituted, and reacted with a polyamine and an aldehyde or ketone.

Description

FUEL STABILIZER COMPOSITION

BACKGROUND OF THE INVENTION Field of the invention.

This invention relates to stabilizing fuels, in particular diesel fuels, against discoloration which is sometimes associated with formation of insoluble material.

INTRODUCTION TO THE INVENTION Fuels generally, and in particular middle distillate fuels are susceptible to the formation of insoluble materials. The insolubles cause blockages in fuel lines, fuel filters and in exaggerated situations in storage tanks. The fuel insoluble materials may also manifest as blockage of a fuel injector tip in a diesel engine. Wherever the location of the gelation, the fuel will not flow and thus the intended usage of the fuel is not possible.

The formation of insolubles in a middle distillate fuel is usually associated with a color change in the fuel. All color changes in a middle distillate fuel do not, however, indicate that insolubles formation is immi¬ nent. Accordingly, when discoloration of the middle distillate fuel is observed, the user will not know if it is safe to utilize the fuel. As testing of small quanti¬ ties of fuel for tendencies to form insolubles is imprac¬ tical the consumer must rapidly consume the fuel. Even rapid consumption of the fuel is no guarantee that the fuel will not have insolubles form before the fuel is exhausted. Alternatively, the fuel may be returned to the distributor or treated to prevent insolubles formation either of which is a major expense. Accordingly, the present invention deals with inhibiting color formation in fuels in which the discoloration may or may not be related to insolubles formation. The compositions herein also are useful in treating middle distillate fuels to prevent insolubles formatio .

It is known from United States Patent 3,351,662 issued November 7, 1967 to Chamot that normally liquid petroleum distillate fractions may be treated for color and sludge through the use of organic polyamines with at least one primary amino group reacted with formaldehyde or acetaldehyde and hydroxybenzaldehyde. Chamot makes similar disclosures in United States Patent 3,184,294 issued May 18, 1965. Newkirk in United States Patent 3,654,158 issued April 4, 1972 discloses inhibiting corrosion in hydrocarbon systems through the use of bis-l,3-alkylamino-2 propanol.

United States Patent 4,647,290 issued March 3, 1987 to Reid describes color stabilized distillate fuels containing N-(2-aminoethyl)piperazine and N,N-diethyl- hydroxylamine. Reid makes similar disclosures in United States Patent 4,648,885 issued March 10, 1987 and further includes in his color stabilizing system triethylenetetra- amine. Lastly, Reid describes similar chemistry in United States Patent 4,647,289 also issued March 3, 1987.

United States Patent 3,936,279 issued February 3, 1976 to Alink describes the use of hexahydropyrimidines to inhibit distillate fuel deterioration. Thompson et al in United States Patent 4,311,841 issued January 19, 1982 describes the further use of hexahydropyrimidines as deterioration inhibitors in hydrocarbon fuel. Gattuso in

United States Patent 4,003,718 issued January 18, 1977 describes the use of substituted tetrahydropyrimidines as being useful in petroleum distillates such as gasoline. Kwong et al in Unites States Patent 4,284,415 issued August 18, 1981 describes inhibiting sedimentation and retarding degradation of hydrocarbon fuels through the use of a reaction product of an alkoxyalkylamine with an epihalohydrin. Kwong discloses similar chemistry relating to poly(oxyalkylene) amine reaction products with an epihalohydrin for inhibiting sedimentation and retarding degradation of hydrocarbon fuels in United States Patent 4,239,497 issued December 16, 1980. Hanson in United States Patent 4,242,212 issued December 30, 1980 describes Mannich additives formed from a 2,4- or 2,6-ditertiary alkyl "hindered" phenol, a polyamine, a formaldehyde yielding reagent and at least one hydrocarbon compound with at least one active or acidic hydrogen. United States Patent 3,948,619 to Worrel issued April 6, 1976 describes cleaning of an internal combustion engine using gasoline containing a detergent amount of the condensation product of phenol and preferably a high molecular weight alkylphenol, an aldehyde and an amine having a free -N(H)- group. It is disclosed in United States Patent 4,509,932 issued April 9, 1985 to Braxton that a minor amount of an alkyldiethylamine may be added to distillate fuel to stabilize against deterioration.

Otto in United States Patent 3,649,229 issued March

14, 1972 describes the reaction products of high molecular weight alkyl substituted hydroxy aromatic compounds, amines and aldehydes as being a detergency improver for a liquid hydrocarbon fuel.

Hanlon in United States Patent 4,553,979 issued No¬ vember 19, 1985 discloses reducing coking around injector nozzles in distillate fuel compositions containing an organic nitrate ignition accelerator and the condensation product of a phenol, preferably a high molecular weight alkylphenol, an aldehyde and an amine having a -N(H)- group. Sung et al in United States Patent 4,501,595 issued February 26, 1985 discloses a diesel oil of im¬ proved storage stability containing the condensate of tetraethylenepentamine; paraformaldehyde 2,6-di-t-butyl- phenol and polyisobutenyl succinic anhydride. United States Patent 4,166,726 issued September 4, 1979 to Harle describes a fuel additive and fuel composition wherein the additive comprises a polyalkylene amine and the reaction product of an alkylphenol, an aldehyde and an amine. Jackisch in United States Patent 4,116,644 issued September 26, 1978 describes cleaning fuel induction systems through the use of gasoline containing a phenol, and the condensation product of an alkylphenol, an alde¬ hyde and an amine having an -N(H)- group. Chibnik in United States Patent 4,083,699 issued April 11, 1978 des- cribes the detergency properties of a fuel or lubricant being improved by adding a Mannich base product prepared by reacting a high molecular weight alkyl substituted hydroxyaromatic compound, a polyoxyethylene polyamine and an aldehyde. Unites States Patent 3,944,397 issued March 16, 1976 to Gardiner et al describes the preparation of a gasoline composition and a benzyl polyamine compound where the benzyl group is hydroxy-substituted. Gardiner also des¬ cribes concentrates of the active ingredient in a hydro- carbon solvent. Japanese Laid-Open patent publication no. 63-386 filed June 19, 1986 describes fuel oil stabilizer compositions. Japanese 63 30,594 describes light cycle oils from desulfurized heavy oils which are hue stabli- lized with a compound containing phenolic and polyamine structures.

While many compositions have been utilized in the art for middle distillate fuel stabilization and color protec¬ tion none have proved to be as useful as the compositions- of the present invention. Accordingly this invention relates to a method of inhibiting color formation and avoiding insolubles formation in middle distillate fuel compositions.

To the extent that the references cited herein are applicable to the present invention they are herein in- corporated by reference. Throughout the specification and claims, percentages and ratios are by weight, and tempera¬ tures are in degrees Celsius unless otherwise indicated. Ranges are exemplary and may be combined. Pressures where given are in KPa gauge unless otherwise indicated.

SUMMARY OF THE INVENTION The present invention deals with a composition comprising:

(A) a middle distillate fuel; and (B) the reaction product of a hydrocarbyl and hy- droxy substituted aromatic compound; an aldehyde or ketone; and at least one alkylene polyamine. This invention further describes a composition comprising: (A) a middle distillate fuel; and,

(B) the reaction product of a monohydrocarb l sub¬ stituted phenol; formaldehyde; and ethylene diamine. Yet another feature of the present invention is a composition which comprises: (A) A middle distillate fuel; and, (B) a compound of the formula RPh(OH)CH₂NHC₂H₄ HCH₂Ph(OH)R; wherein R is at least one hydrocarbyl substituent, and Ph(OH) is an aromatic hydroxyl containing moiety. A further feature of the invention is a composition comprising:

(A) a middle distillate fuel; and,

(B) the reaction product of [R]_mPh(OH) [CfR^ ( ₂)X]_n; and an alkylene polyamine, wherein Ph(OH) is a phenolic residue, R is at least one hydrocarbyl substituent; R. is hydrogen or a hydrocarbyl group; R- is hydrogen or a hydrocarbyl group; X is (R_)„N-, OH or OR., where R., is a hydrocarbyl group; n is from 1 to 3; m is 0 to 2 wherein n+m is not greater than 5.

This invention also describes a method of inhibiting color formation in (A) middle distillate fuel by adding to the fuel a sufficient amount of (B) the reaction product of a hydrocarbyl and hydroxy substituted aromatic com- pound; an aldehyde or ketone; and an alkylene polyamine.

The present invention also describes a method for inhibiting color formation in a middle distillate fuel comprising contacting the middle distillate fuel (A) with a sufficient amount of a compound of the formula RPh(OH)CH₂NHC₂H₄NHCH₂Ph(OH)R wherein R is a hydrocarbyl substituent, and Ph(OH) is an aromatic hydroxy moiety. Still another feature of the present invention is a method for inhibiting color formation in a middle distil¬ late fuel comprising contacting the middle distillate fuel (A) with (B) the reaction product of

[R] Ph(OH) [C(R₁) (R₂)X]_n; and an alkylene polyamine, wherein Ph(OH) is a phenolic residue; R is at least one hydrocarbyl substituent; R__. is hydrogen or a hydrocarbyl group; R₂ is hydrogen or a hydrocarbyl group; X is (R,)_N-, OH or OR, where R, is a hydrocarbyl group; n is from 1 to 3; and is 0 to 2 wherein n+m is not greater than 5 wherein the amount of (B) is sufficient to inhibit color formation in (A) .

DETAILED DESCRIPTION OF THE INVENTION The present invention as previously described deals with inhibiting or minimizing color formation in a middle distillate fuel. Typically a middle distillate fuel is a hydrocarbon source fuel which is used in a power plant, in home heating oils, jet fuels, kerosene or as a diesel fuel. In particular the present invention deals with diesel fuels.

Diesel fuels are typically defined by a specification prescribed by the American Society for Testing Materials. This specification known as ASTM D 975-81 adequately describes the major aspects of the present invention including the definition of a diesel fuel.

As previously noted, there need be nothing wrong with the diesel fuel in order to treat the fuel with the compo¬ sitions of the present invention. That is, it is not known exactly why some diesel fuels change color and form insolubles while other fuels may change color and do not form insolubles. One theory is that high sulfur content diesel fuels are more susceptible to forming insolubles and discoloration, particularly when exposed to heat, than are diesel fuels which are essentially free of sul¬ fur. Sulfur is usually present in fuels from naturally occurring organosulfur compounds. Sulfur in a middle distillate fuel may be present as an unintended by-product of refining such that the sulfur is reacted into one or more organic components in the middle distillate fuel. Typically, when sulfur is found to be a problem in a mid¬ dle distillate fuel it is because the sulfur is present at 0.1 pp to 20,000 ppm as sulfur based on the weight of the middle distillate fuel.

In any event, as the ultimate customer has no way of knowing if the fuel will form insolubles due to an onset of color change, the present invention gives the assurance of obtaining a product in which color formation is minimized. The next aspect of the present invention is the discussion of the hydrocarbyl and hydroxy substituted aromatic compound. The hydrocarbyl and hydroxy substi¬ tuted aromatic compound may be a mononuclear or polynucle- ar aromatic compound. It is preferred that mononuclear aromatic compounds are the basis for the hydrocarbyl and hydroxy substituted aromatic compound. The hydroxy groups are typically present as a monohydroxy group on the mono¬ nuclear aromatic compound. At least, it is desired that there only be one hydroxy group per aromatic nuclear group. The hydrocarbyl substituent on the hydrocarbyl and hydroxy substituted aromatic compound typically contains up to 150 carbon atoms, preferably from 2 to about 30 carbon atoms, more preferably about 3 to about 20 carbon atoms, and most preferably about 6 to about 18 carbon atoms.

The hydrocarbyl substituent may be saturated or un- saturated although the former is preferable. Branched chain hydrocarbyl substituents are preferred to straight chain hydrocarbyl substituents. Polyisopropylene and polyisobutylene are the preferred hydrocarbyl substituents.

In one aspect of the invention the hydrocarbyl sub¬ stituted aromatic hydroxyl containing moiety as shown in the Summary has R as previously described with being from 0 to 2, preferably 1. The values of R_. and „ are independently hydrogen or a hydrocarbyl group. Where R.. and R are other than the preferred hydrogens, the hydro¬ carbyl groups typically contain from 1 to 5 carbon atoms. Thus R-. or R~ may conveniently be methyl or ethyl groups. The value of X is defined as (R,)₂N-, a hydroxyl (-OH) , or

OR, where R, is a hydrocarbyl group as described for R. The value of n is from 1 to 3 and is preferably 1. The sum of n plus m is not greater than 5, e.g. the remaining valences on a mononuclear aromatic phenol.

The second component of the reaction product (B) is an aldehyde or a ketone. The aldehydes are of the formula R. (C=0)H whereas the ketone is of the formula R,-(C=0)R_g. R. is hydrogen or a hydrocarbyl group in an aldehyde. The values of R D_ and RO, are such that each are hydrocarbyl groups in a ketone. The foregoing hydrocarbyl groups typ- ically contain from 0 to 10 carbon atoms and are prefer¬ ably saturated groups.

Typical examples of the aldehyde or ketone include formaldehyde, acetaldehyde, propanal, dimethyl ketone, diethyl ketone, methylisobutyl ketone, and the like. Pre- ferably the aldehyde is formaldehyde and may be used in any form such as formalin or paraformaldehyde.

The alkylene polyamine utilized in the present inven¬ tion is typically of the formula

H2„N(CnH2„nNH)x(CaH2,aNH),bCcH2„cNH2„ wherein n is an integer, a is an integer, b is an integer, and c is an integer. Typically the values for the compo¬ nents are where x, a, and b are all zero and c is 2. The preferred polyamine monomeric units are based on ethylene diamine or propylene diamine. The preferred species in the present invention is ethylene diamine, or its polymers triethylene tetramine, tetraethylene pentamine or penta- ethylene hexamine.

An example of the preparation of the reaction product (B) is shown below as Example I-A. EXAMPLE I-A

Polypropylenephenol (polypropylene M.W. 168) contain¬ ing 74% para-polypropylene substituent, 5,300 grams, tet- raethylenepentamine 1,912 grams, and toluene 1,775 grams are placed in a reactor, and 1,686 grams of 36% aqueous formaldehyde are added over a period of 90 minutes. The reaction mixture is refluxed for 11 hours, during which period 1,440 ml of water is separated. The reaction mixture is filtered through diatomaceous earth.

The neat recovered product will have 4.5% by weight nitrogen content. Theoretical is 4.6% nitrogen.

Some of the alkyl- and hydroxy-substituted benzyl polyamine containing different amounts of benzyl groups prepared by using a procedure essentially as described above are listed below. In each case the desired product is obtained by choosing the proper molar ratios of poly- propylenephenol, formaldehyde and polyamine. The poly- propylenephenol (polypropylene M.W. 168) contains about 60% of the polypropylene group in the para position.

Mole Ratio of Polypropylenephenol:HCHO:Polyamine Polyamine

Preparation B 2:2:1 ethylenediamine Preparation C 1:1:1 triethylenetetramine Preparation D 2:2:1 triethylenetetramine Preparation E 3:3:1 triethylenetetramine Preparation F 4:4:1 triethylenetetramine Preparation G 1:1:1 tetraethylenepentamine Preparation H 2:2:1 tetraethylenepentamine Preparation I 3:3:1 tetraethylenepentamine Preparation J 5:5:1 tetraethylenepentamine Preparation K 5:10:1 triethylenetetramine

Generally, the molar ratio of the aromatic compound, the aldehyde and the alkylene polyamine is respectively about 1:1:1 to about 5:10:1, preferably 2:1:1 to 3:3:1, and is most preferably 2:2:1. For instance, respective molar ratios of the hydrocarbyl and hydroxy substituted aromatic compound; the aldehyde or ketone; and the alkyl¬ ene polyamine are 2:2:1; 1:1:1; 2:1:2; 1:2:2; and the like.

The general reaction conditions are to premix the alkylene polyamine with the hydrocarbyl and hydroxy substituted aromatic compound together with any suitable solvent. Suitable solvents include xylene, toluene or benzene. The aldehyde or ketone may be simply added as a convenient aqueous mixture thereof.

The reaction proceeds at reflux for a sufficient period of time to ensure substantial completion of the desired reaction. Typically, the reaction times vary from one hour to twenty-four hours. If desired, the aldehyde or ketone may be added intermittently. A preferred method for conducting the reaction is to remove water as it is formed together with any incidental water which is present from the reactants.

The product may be recovered in the solvent for convenience and filtered through suitable filtering material.

USAGE OF THE PRODUCT

The products of the present invention are typically utilized as a very small quantity based on the total middle distillate fuel treated. The amount of (B) em- ployed is simply that sufficient to stabilize a given fuel against color deterioration. Typically the amount of the reaction product (B) will be about 5 parts to about 2000 parts per million parts of fuel treated. A preferred range for the utilization of the reaction product (B) in fuel is from 50 parts to 1,500 parts per million parts of fuel.

The reaction product (B) is conveniently blended directly into the fuel at the refinery. As component (B) tends to be fuel soluble very little mixing is required and it may be metered directly into a fuel stream. If desired the reaction product (B) may be premixed with a quantity of suitable solvent (including the middle distil¬ late fuel or component thereof) and then diluted out in the fuel to be treated. The solvents are conveniently those used to prepare (B) .

The following is an example of the treatment of a diesel fuel according to the present invention.

EXAMPLE

A diesel fuel is obtained and combined with the active of Example I-A. To facilitate mixing the active is first diluted with xylene at a 4:1 active to solvent weight ratio. The active is added to the fuel at 115 parts per million parts of the fuel.

The product is then tested for storage stability. At the end of the test period the color and insolubles formation is determined. The product described herein achieved a pass rating for color and insolubles formation. Substantially similar results are obtained using the active at 165 ppm, 330 ppm, 495 ppm, 742.5 ppm and 1000 ppm. Larger amounts of the active provide longer protec¬ tion for the fuel. Further use of Preparations B-K give similar results.

Claims

What is claimed is:

1. A composition comprising:

(A) a middle distillate fuel; and

(B) the reaction product of a hydrocarbyl and hydroxy substituted aromatic compound; an aldehyde or ketone; and at least one alkylene polyamine.

2. The composition of claim 1 wherein the aromatic compound is a monohydroxy aromatic compound.

3. The composition of claim 1 wherein (B) employs an aldehyde.

4. The composition of claim 1 wherein the hydro¬ carbyl substituent on the aromatic compound is saturated.

5. The composition of claim 1 wherein the alkylene polyamine is ethylene diamine.

6. The composition of claim 4 wherein the hydro¬ carbyl substituent is a propylene oligomer.

7. The composition of claim 1 wherein the aromatic compound is monohydrocarbyl substituted.

8. The composition of claim 1 wherein the molar ratio of the aromatic compound; the aldehyde; and the alkylene polyamine is respectively about 1:1:1 to 5:10:1.

9. The composition of claim 1 wherein (B) is utilized at about 5 to about 2000 ppm to component (A) .

10. The composition of claim 1 wherein the hydro¬ carbyl substituent of the aromatic compound contains from 2 to about 30 carbon atoms.

11. The composition of claim 3 wherein the aldehyde is forma1dehyde.

12. The composition of claim 1 wherein the alkylene polyamine is selected from the group consisting of diethylene triamine and triethylene tetramine.

13. A composition comprising:

(A) a middle distillate fuel; and, (B) the reaction product of a monohydrocarbyl substituted phenol; formaldehyde; and ethylene diamine.

14. A composition which comprises:

(A) A middle distillate fuel; and,

(B) a compound of the formula RPh(OH) CH₂NHC₂H₄NHCH₂Ph(OH)R; wherein R is at least one hydrocarbyl substituent, and Ph(OH) is an aromatic hydroxyl containing moiety.

15. The composition of claim 14 wherein R is a polypropylene oligomer.

16. The composition of claim 14 wherein R is a single hydrocarbyl substituent on the aromatic group.

17. The composition of claim 14 wherein R is a saturated hydrocarbon.

18. The composition of claim 14 wherein R contains about 6 to about 18 carbon atoms.

19. The composition of claim 14 wherein (B) is present at about 5 to about 2000 ppm based on component (A).

20. A method of inhibiting color formation in (A) a middle distillate fuel by adding to the fuel a sufficient amount of (B) the reaction product of a hydrocarbyl and hydroxy substituted aromatic compound; an aldehyde or ketone; and an alkylene polyamine.

21. The method of claim 20 wherein the fuel is diesel fuel.

22. The method of claim 20 wherein (B) employs formaldehyde.

23. The method of claim 20 wherein (B) is present at 5 ppm to 2000 ppm based on (A) .

24. A method for inhibiting color formation in a middle distillate fuel comprising contacting the middle distillate fuel (A) with a sufficient amount of a compound of the formula RPh(OH)CH₂NHC₂H₄NHCH₂Ph(OH)R wherein R is a hydrocarbyl substituent, and Ph(OH) is an aromatic hydroxy moiety.

25. The method of claim 24 wherein the fuel is diesel fuel.

26. A composition comprising:

(A) a middle distillate fuel oil; and,

(B) the reaction product of

[R]mPh(OH) [C(Rl_n) (R λ,)X]n; and an alkylene polyamine, wherein Ph(OH) is a phenolic residue, R is at least one hydrocarbyl substituent; R.. is hydrogen or a hydrocarbyl group; R« is hydrogen or a hydrocarbyl group; X is (R,)₂N-, OH or OR, where R, is a hydrocarbyl group; n is from 1 to 3; m is 0 to 2 wherein n+m is not greater than 5.

27. The composition of claim 26 wherein the alkylene polyamine is ethylene diamine.

28. The composition of claim 26 wherein the hydro- carbyl substituent is a propylene oligomer.

29. The composition of claim 26 wherein the weight ratio of (B) is about 5 to about 2000 ppm based on (A) .

30. A method for inhibiting color formation in a middle distillate fuel comprising contacting the middle distillate fuel (A) with (B) the reaction product of

[R] Ph(OH) [C(R₁) (R₂)X] ; and an ' alkylene polyamine, wherein Ph(OH) is a phenolic residue, R is at least one hydrocarbyl substituent; R., is hydrogen or a hydrocarbyl group; _ is hydrogen or a hydrocarbyl group; X is

(R,)₂N-, OH or OR, where R, is a hydrocarbyl group; n is from 1 to 3; and is 0 to 2 wherein n+m is not greater than 5 wherein the amount of (B) is sufficient to inhibit color formation in (A) .

31. The method of claim 30 wherein the alkylene polyamine is ethylene diamine.

32. The method of claim 30 wherein the hydrocarbyl substituent R is a propylene oligomer and m is 1.

33. The method of claim 30 wherein the molar ratio of

[R^PhfOH) [C(R₁(R₂)X]_n; to the polyamine respectively is about 1:1 to about 3:1.

34. The method of claim 30 wherein the weight ratio of B is about 5 to about 2000 ppm based on (A) .