CA2027269A1

CA2027269A1 - Method of dehazing hydrocarbon fuels

Info

Publication number: CA2027269A1
Application number: CA 2027269
Authority: CA
Inventors: James G. Foley; Fred J. Beck
Original assignee: Petrolite Corp
Current assignee: Baker Petrolite LLC
Priority date: 1989-10-12
Filing date: 1990-10-10
Publication date: 1991-04-13

Abstract

Abstract of the Disclosure A hydrocarbon fuel may be dehazed by mixing with the reaction product of (1) an alkenyl or alkyl succinic acid or anhydride, and (2) an alkylether diamine.

Description

~ ~ ~J

METHOD OF DEHAZING HYDROCARBON FUELS

Backaround of the Invention This invention relates to the dehazing of hydrocar~on fuels. In particular, the invention relates to chemical means for dehazing such fuels.

In the commercial transportation and storage of hydrocarbon fuels such as gasoline, diesel fuel, jet fuel, turbine oils, and fuel oils, the fuel sometimes comes in contact with water. Often the result is an emulsion of water in the fuel which gives the fuel a cloudy appearance referred to as "haze". Because haze in a fuel is associated with low grade, contaminated, or degraded fuels, it is commercially important to break the emulsion and "dehaze" the fuel.

Various chemical means such as oxyalkylated phenol formaldehyde resins are used for dehazing fuels. One limitation is that chemical dehazers do not have universal application. Whether due to innate differences in the fuel itself, various contaminates, decomposition products, or performance additives, dehazers that work well for one fuel will perform only marginally in another. In general, a specific hazy fuel is evaluated by subjecting it to a battery of dehazing agents and the best performer is then selected for full scale use. In view of the variety of fuels and conditions which contribute to haze formation, an additional chemical dehazer would be an advance to the art of fuel dehazing.

US 4,326,987 (Hendricks - Petrolite, 1982) discloses the reaction product of (a) an alkenyl or alkyl succinic acid or anhydride with (b) an alkylether diamine; and the use of that reaction product as a corrosion inhibitor for hydrocarbon fuels.

Summary of the Invention Briefly, the invention is a method of dehazing a hazy hydrocarbon fuel, by contacting the fuel with the reaction product of (a) an alkenyl or alkyl succinic acid or anhydride, and (b) an alkylether diamine.

In another respect, the invention i8 the dehazed fuel resulting from the above method.

The method of the invention is particularly economical and convenient to carry out. The fuels of the invention are relatively free of haze and have a desirable physical appearance.

Detailed Description of the Invention In this specification and claims, numerical ranges are not critical unless otherwise stated. That is, the numerical values may be read as if they were prefaced with the word "about" or "substantially".

A first component of the invention is an alkenyl or alkyl succinic acid or anhydride. These compounds have the general formulas:

O O

R CH- C R CH - C
\ I \
I OH
CH2 -ICl I OH

(anhydride) O

(acid) wherein R is an alkenyl or alkyl radical having at least 2 carbon atoms.

R may be straight or branched. If unsaturated, R

may be saturated by addition of hydrogen, sulfur, or a halogen, but unsaturation is preferred. R must have at least 2 carbon atoms and desirably has 2 to 32, more desirably 4 to 28, preferably 6 to 24, more preferably 8 to 18, and more preferably 10 to 14 carbon atoms.

Although the anhydride form may be used, the acid is preferred.

Examples of suitable succinic acid or anhydride compounds include ethenyl succinic anhydrides; ethenyl succinic acid; ethyl succinic anhydride; propenyl succinic anhydride; sulfurized propenyl succinic anhydride; butenyl succinic acid; 2-methyl-butenyl succinic anhydride; 1,2-dichloropentyl succinic anhydride; hexenyl succinic anhydride; hexyl succinic acid; sulfurized 3-methyl-pentenyl succinic anhydride;
2,3-dimethylbutenyl succinic anhydride;
3,3-dimethylbutenyl succinic acid;
1,2-dibromo-2-ethylbutyl succinic acid, heptenyl succinic anhydride; 1,2-diodooctyl succinic acid; octenyl succinic anhydride; 2-methylheptenyl succinic anhydride;

4-ethylhexenyl succinic acid; 2-isopropylpentyl succinic anhydride; nonenyl succinic anhydride; 2-propylhexenyl succinic anhydride; decenyl succinic acid; decenyl succinic anhydride; 5-methyl-2-isopropylhexenyl succinic anhydride; 1,2-dibromo-2-ethyloctenyl succinic anhydride;
decyl succinic anhydride; undecenyl succinic anhydride;
1,2-dichloro-undecyl succinic acid; 3-ethyl-2-t-butylpentenyl succinic anhydride; dodecenyl succinic anhydride; dodecenyl succinic acid; 2-propylnonenyl succinic anhydride; 3-butyloctenyl succinic anhydride;
tridecenyl succinic anhydride; tetradecenyl succinic anhydride; hexadecenyl succinic anhydride; sulfurized octadecenyl succinic acid; octadecyl succinic anhydride;
1,2-dibromo-2-methylpentadecenyl succinic anhydride, 8-propylpentadecyl succinic anhydride; eicosenyl succinic anhydride; 1,2-dichloro-2-methylnona decenyl succinic anhydride; 2-octyldodecenyl succinic acid;
1,2-diiodotetracosenyl succinic anhydride; hexacosenyl succinic acid; hexacosenyl succinic anhydride; and hentriacontenyl succinic anhydride. The preferred compound is tetrapropenyl succinic acid (dodecenylsuccinic acid).

The methods of preparing the alkenyl and alkyl succinic acids and anhydrides are well known to those lS skilled in the art. For instance, the most feasible method of preparing alkenyl succinic anhydrides is by the reaction of an olefin with maleic anhydride. Since relatively pure olefins are difficult to obtain, and when obtainable are often too expensive for commercial use, alkenyl succinic anhydrides are usually prepared as mixtures by reacting mixtures of olefins with maleic anhydride.

A second component of the invention is an alkyether diamine, preferably having the formula Rl~R2NHR3NH2 _ ~.J ~ .`J 5 ;_' '.,' -J

wherein Rl is a Cl to C18, desirably C4 to C14, preferably C6 to C12, and more preferably C8 to C10 alkyl moiety, and R2 and R3 are each independently C2 to C12, desirably C2 to C10, preferably C2 to C5, and more preferably C3 alkyl moieties. The preferred alkylether diamine is CH3(cH2)7-9o(cH2)3NH(cH2)3NH2 The reaction products are prepared by mixing the components together at ambient temperature. Since the reaction is exothermic, cooling may be desirable in larger batches.

The molar ratio of acid/anhydride to amine is generally 1:1 to 1~:1, desirably 1:1 to 8:1, preferably 1.5:1 to 6:1, most preferably 2:1 to 4:1.

Since the reaction products are generally solids, they are conveniently used in the form of solutions.
Because of their low price and good solution characteristics, aromatic hydrocarbons are the preferred solvents.

Further details concerning the reactants, the reaction methods, and the reaction products may be found in the aforementioned US 4,326,987, which is incorporated herein by reference.

J

The reaction products are useful to remove haze from hydrocarbon fuels such as gasoline, diesel fuel, jet fuel, turbine oils, and fuel oils. The haze is removed by contacting the hazy fuel with a dehazing amount of the reaction product. By "dehazing amount" is meant an amount that will measurably reduce the amount of haze present. Generally, the reaction products will be used at 1 to 1,000 ppm (parts per million), desirably 5 to 800 ppm, preferably 10 to 500 ppm, and more preferably 30 to 300 ppm.

The contacting may be accomplished by simply pouring the reaction product into the fuel. However, it is greatly preferred that the containing include thorough mixing, such as by shaking, pumping, or stirring.

As the dehazing takes place, droplets of water will coalesce and fall to the bottom of the fuel, allowing the water and fuel to be separated.

Importantly, the compounds useful in the invention will dehaze not only pure fuels, but also fuels containing additives such as pour point depressants (cold flow improvers). The invention is applicable to a wide variety of hydrocarbon fuels under a wide variety of conditions.

~ ` ~ ? ~:
1 , ;:. . / ., .. j The invention will be further explained in the following examples. In the examples, all parts and percentages are by weight unless otherwise specified.

Example 1 99 ml of fuel oil (furnace oil) containing 70 ppm (volume) of a chlorine-containing pour point depressant (sold as TOLAD~ T-35 by Petrolite Corporation) and 1.O ml of tap water (pH = 9.0) were emulsified by mixing for 60 seconds at high speed in a stainless steel malt cup on a Hamilton Beach mixer (Model 936) equipped with a fly leaf agitator. The emulsified fuel, now having a distinctly hazy appearance, was transferred to a series of glass containers. Various amounts of the reaction product of a 3:1 (molar ratio) mixture of dodecenylsuccinic acid and CH3(cH2)7-so(cH2)3NH(cH2)3NH2~ in the form of a 29.0%
solution in aromatic hydrocarbons (identified as compound "I"), were added, followed by shaking for 2 minutes on a shaking machine set at 130 shakes per minute. The degree of haze was then monitored at various intervals by measuring light transmittance with a Brinkmann colorimeter tModel PC-800) equipped with an 830 nm filter and a stainless steel probe having a 20 nm path length.
The results are reported in Table I.

Comparative Example 1 Following the procedure of Example 1, the evaluation was repeated with an oxyalkylated alkylphenolic resin tin a 33.5% active solution) commercial dehazer, sold as TOLAD T-500 by Petrolite Corporation (identified as compound C-1); an oxyalkylated alkylphenolic resin and a fatty amine-aryl quaternary (in a 37.7% active solution), emulsion preventive, sold as AR-35 by Petrolite Corporation (identified as compound C-2); and an oxyalkylated alkylphenolic resin and polyamines (in a 43.9% active solution) demulsifier, sold as Experimental Product EXI-382 by Petrolite Corporation (identified as compound C-3). The results are shown in Table I.

~n o~ ~ _c~o, o~
N l~ l O ~ l l ~ ~ ~ ~ l l l l l CU ~ _ CO ~ OJ 1~ 0 _ O 0 ~ It~
,_ C r 1 ul ~ ~ I I ~ I I u~ 0 0 1 1 u~

X
o~ 0 ~ o <~l - ~ O~ o rl ~ o u~ ~O O o C ~ U~ o o~ ~ 0 ~ ~ o ~ 0 ~0 0 ~ ~ o ~ ~_ ~ U~ 00 ~ N O ~ O u~ O ul O Ir~ U~ O ~ _ ~ O ~
c ~1 ` ` Z~ ~; 0 ie ~ U~ ,~ 01~ ~ ~ ul ~o ~

~_ ~ 0` 0 ~ ~ 0 ~ ~ ~ o ~ o~ ~ ~ ~ I O`
u u ~ o ~ u~ 0 ~t 2 ~ ~ ~o o ~ ~ _ 0 Ll O O O ~ O g 1/1 O O O O 1~ O ~ O O O O O O O
.~
~ ,Co L C _~ = = = = L~ . == = = Ll ~ C
O-IS
_c C O O O O O O~ 00 0~ O _ ~ ~ ~J U~ `O 1~ CO O` O O ~
_ _____ ._________ _~

Example 2 and Comparative Example 2 The procedure of Example 1 and Comparative Example 1 were followed except that instead of tap water, a buffer solution of pH 4 (Fisher Scientific S0-B-101), pH 7 (Fisher Scientific S0-B--107), or pH 10 (Fisher Scientific S0-B-115) was used. Also, in some tests at pH = 7, the pour point depressant was not present in the fuel oil. The data are shown in Table II.

: " "~ ` , J ` ,' ~J

O` l l l l l l l l l l l O` U~ _ N

~ ~ ~ J O ~ ~ CO N ~ N
._N 0~ ~7 0~ CO 1~ 1~1 ¦ 0 1 5 1 n ¦~ N I 0 1~ ~ S O O~ U~ 11 ~O 0 al 1/~ 'O ~ ~ O ~O 1~
¦N 0~ t~ u~ `O ~ o o ~ ~ ~ I~ 0~ 0 ~ U~ iii~ OD

~ 1~ N U~ ~ ~ _ ~ N O 0~ U~ `O ~ ~--O N U~ `O O ~ O 1/~ ~0 C r~ N 1.'1 t'7 O~ O~ ~5 X~ ~ N 0. 0 i~ ~0 1~

wl~ .==== ,===== ===== =

~==== =:=::= C_=== ~,=:::::

~ n~ o .> v u~cOu~ ~no~ t_O~ ~u~U~or' O O ~ ~ ~ ~ O CO ~ O --I~i O 00 0 _ ~ 0 C17 m o v ~_ N 000000 00000 0000000 '-~
~c ~,0 o _ . . = c IJ L~ L~ cO ~ . . ~ C ~J ~ O n~
~ n~ c 00000 ~0`0 ___~_ ___NNNN 00 NNNNN ~NN~NN NNNNN NNNNNNN ~ _

Claims

1. A method of dehazing a hazy hydrocarbon fuel comprising contacting the fuel with a dehazing amount of the reaction product of (a) an alkenyl or alkyl succinic acid or anhydride; and (b) an alkylether diamine.

2. The method of claim 1 wherein the alkylether diamine has the formula wherein R1 is an alkyl moiety and R2 and R3 are alkylene moieties.

3. The method of claim 2 wherein R1 has 1 to 18 carbon atoms and R2 and R3 each independently have 2 to 12 carbon atoms.

4. The method of claim 3 wherein R1 has 4 to 14 carbon atoms and R2 and R3 each independently have 2 to 10 carbon atoms.

5. The method of claim 4 wherein R1 has 8 to 10 carbon atoms and R2 and R3 each independently have 2 to 5 carbon atoms.

6. The method of claim 1 wherein the alkenyl or alkyl succinic acid or anhydride is an acid.

7. The method of claim 1 wherein the alkenyl or alkyl succinic acid or anhydride is an alkenyl succinic acid or anhydride.

8. The method of claim 1 wherein the alkenyl or alkyl succinic acid or anhydride is an alkenyl acid.

9. The method of claim 8 wherein the alkenyl moiety is a C2 to C32 moiety.

10. The method of claim 9 wherein the alkenyl moiety is a C6 to C24 moiety.

11. The method of claim 10 wherein the alkenyl moiety is a C10 to C14 moiety.

12. The method of claim 1 wherein said reaction product is made with a molar excess of alkenyl or alkyl succinic acid or anhydride.

13. The method of claim 12 wherein the molar ratio of alkenyl or alkyl succinic acid or anhydride to alkylether diamine is 1:1 to 10:1.

14 8834 14. The method of claim 13 wherein the molar ratio of alkenyl or alkyl succinic acid or anhydride to alkylether diamine is 1.5:1 to 6:1.

15. The method of claim 1 wherein the reaction product is present at 1 to 1,000 ppm in the fuel.

16. The method of claim 15 wherein the reaction product is present at 10 to 500 ppm in the fuel.

17. The method of claim 1 wherein the reaction product is in the form of a solution.

18. The method of claim 17 wherein the solution is a solution in an aromatic hydrocarbon.

19. The method of claim 1 including the further step of mixing the reaction product and the fuel.

20. The method of claim 1 including the further step of removing water which has separated from the fuel.

21. The method of claim 19 including the further step of removing water which has separated from the fuel.

22. The fuel resulting from the method of claim 1.