EP0677095A4

EP0677095A4 - Distillate fuels comprising multifunctional dialkylamino alkylether cyanurate additives.

Info

Publication number: EP0677095A4
Application number: EP94905489A
Authority: EP
Inventors: David Joseph Baillargeon; Angeline Baird Cardis; Dale Barry Heck; Susan Wilkins Johnson
Original assignee: Mobil Oil Corp
Current assignee: ExxonMobil Oil Corp
Priority date: 1992-12-30
Filing date: 1993-12-22
Publication date: 1995-12-20
Also published as: FI953227A0; CA2148496A1; EP0677095A1; JPH08505620A; FI953227A; WO1994016040A1

Abstract

Additives which improve the low-temperature properties of distillate fuels are the ether-type reaction products of (1) reactive hydrocarbyl halides and (2) an aminoalcohol or mixtures of aminoalcohols, or aminoalcohols/amines.

Description

DISTILLATEFUELSCOMPRISINGMULTIFUNCTIONALDIALKYLAMINOALKYLETHER CYANURATE ADDITIVES.

This invention is directed to multifunctional additives comprising ether-type reaction products which improve the low-temperature properties of distillate fuels.

Traditionally, the low-temperature properties of distillate fuels have been improved by the addition of kerosene, sometimes in very large amounts (5-70 wt %) . The kerosene dilutes the wax in the fuel, i.e., lowers the overall weight fraction of wax, and thereby lowers the cloud point, filterability temperature, and pour point simultaneously. The additives of this invention effectively lower both the cloud point and CFPP (Cold Filter Plugging Point) of distillate fuel without any appreciable dilution of the wax component of the fuel.

Other additives known in the art have been used in lieu of kerosene to improve the low-temperature properties of distillate fuels. Many such additives are polyolefin materials with pendent fatty hydrocarbon groups. These additives are limited in their range of activity; however, most improve fuel properties by lowering the pour point and/or filterability temperature. These same additives have little or no effect on the cloud point of the fuel. The additives of this invention effectively lower distillate fuel cloud point, and thus provide unique and useful advantage over known distillate fuel additives.

U.S. Patent 4,957,650 discloses that in broad boiling distillate fuels ester, ether, or ester/ether additives are typically employed in conjunction with other flow improver additives.

U. S. Patent 4,738,686 provides hydrocarbon fuels having an improved cetane number rating which contain cyclic ether additives such as diketene compounds and diketene-carbonyl adducts.

U. S. Patent 4,682,984 provides an additive particularly designed for vehicular diesel fuel which generally comprises a mixture of aromatic and aliphatic hydrocarbons and a lower aliphatic ether.

The novel ethers and ether/amines prepared in accordance with the invention have been found to be surprisingly active wax crystal modifier additives for distillate fuels. Distillate fuel compositions containing < = 0.1 wt % of such additives demonstrate significantly improved low-temperature flow properties, i.e., lower cloud point and lower CFPP filterability temperature.

These additives are ether or ether/amine products which have core-pendant group (star-like) structures derived from the reaction of a halogen reactive organic "core" with the following "pendant groups": (1) an aminoalcohol, the product of an amine and an epόxide, or (2) a combination of an aminoalcohol and a secondary amine. The aminoalcohols may also encompass a combination of two or more different aminoalcohols.

Thus a primary object of this invention is to improve the low-temperature flow properties of distillate fuels and thereby provide improved fuel compositions. These new additives are especially effective in lowering the cloud point of distillate fuels, and thus improve the low-temperature flow properties of such fuels without the use of any light hydrocarbon diluent, such as kerosene. In addition, the filterability properties are improved as demonstrated by lower CFPP temperatures. Thus, the additives of this invention demonstrate multifunctional activity in distillate fuels.

The additives in accordance with the invention are unique. Also, additive concentrates and fuel compositions containing such additives are unique. Similarly, the processes for making these additives, additive concentrates, and fuel compositions are unique.

Hydrocarbyl as defined herein is an organic radical containing at least carbon and hydrogen atoms. Suitable organic radicals include hydrocarbon groups. Also suitable are organic radicals comprising a hydrocarbon group and further comprising heteroatoms such as oxygen, nitrogen, sulfur and halogen. Examples of suitable hydrocarbon groups include cyclic or acyclic hyrocarbon groups, aliphatic (straight or branched) , cycloaliphatic such as cycloalkyl or cycloalkenyl. The hydrocarbon group may also be aromatic. Organic radicals suitable as hydrocarbyl include the hydrocarbon groups alkyl, alkenyl, alkynyl and aryl. Aryl refers to any aromatic hydrocarbon.

An ether-type reaction product in accordance with the invention may be prepared by a process which comprises the reaction of (1) reactive hydrocarbyl halides and (2) aminoalcohols or mixture of aminoalcohols or aminoalcohols/amines with long-chain hydrocarbyl groups attached thereto. The reaction is carried out under ether and amine formation conditions in substantially molar, less than molar or more than molar amounts at temperatures varying from 85 to 250°C under pressures varying from ambient to about 690 kPa (100 psi) or autogenous for a time sufficient to obtain the desired ether type additive product of reaction containing the desired core- pendant group structures.

The additives of this invention have core- pendant group (star-like) structures. These additives are reaction products obtained by combining the core structure and the pendant group(s) in differing ratios using standard techniques for ether/amine formation.

Suitable pendant groups may be derived from alcohols and amines with some combination of linear hydrocarbyl groups attached. The pendant groups include, but are not limited to, (1) aminoalcohols, derived from a secondary fatty amine capped with an epoxide, and (2) combinations of the aminoalcohol from (1) and a long-chain secondary amine. The aminoalcohol, above, may include one or more different aminoalcohols. A generalized preparation of the aminoalcohols from an epoxide and a secondary amine is illustrated below:

0

H _/C CH 2„. + H-NI-R1. > HO-CJH-CH_-NI-R1.

^R3 ^R2 ^R3 ^R2

Where: R-, R_ = C_ to about C₅ linear hydrocarbyl groups, either saturated or unsaturated and R_? = C. to C_nn_ hydrocarbyl. Preferably R. and R are C_ to C_₄ and R„ is preferably C_₂ to C ..

Amines suitable for use herein should have at least one long-chain hydrocarbyl group containing preferably twelve or more carbon atoms. Highly useful secondary amines include but are not limited to di(hydrogenated tallow) amine, ditallow amine, dioctadecylamine, methyloctadecylamine and the like.

Suitable core structures include hydrocarbon molecules containing at least two or more reactive halide groups (Cl, Br, I) , pseudo-halide groups such as methyl sulfonates, tolyl sulfonates, etc., or low- molecular weight ethers such as methyl or ethyl ether which are susceptible to substitution reactions by reactive nucleophiles. These core structures include, but are not limited to, aromatic, cyclic or alicyclic, aralkyl, alkylaryl, and alkyl hydrocarbons, as well as their corresponding heteroatom-containing analogues. Generally speaking there are at least two reactive groups in the core structure precursor.

The additives of this invention are the reaction products of the "core" and "pendant group" precursors, and a range of reactant stoichiometries may be used. However, each additive requires one "core" derivatized with at least one aminoalcohol "pendant group"; any additional pendant groups may be either aminoalcohols or amines which may be optionally added up to the limit of available reactive groups in the core structure. Residual, unreacted halogen (or other reactive groups) in the reaction product may be removed or reduced by hydrolysis, hydrogenolysis, reduction, or substitution with suitable chemical reagents.

For example, reaction of a selected chloride- containing "core", such as cyanuric chloride (see Table 1) , with an aminoalcohol of the type described above, such as the reaction product of Armeen 2HT/Vikolox 18, gives the desired ether additive product with the release of HC1 as a reaction by¬ product. The aminoalcohol is produced in situ by the reaction of the amine and the epoxide. However, the aminoalcohol may be prepared independently if desired. The same "core" reacted with a suitable secondary amine gives a tertiary amine additive product with an analogous release of HCl as by¬ product.

In addition, these additives may function alone or in the presence of an added pour point additive with additional improvements in cloud point and CFPP activity.

Specific additive compositions and their respective performance for cloud point and CFPP are given in Table 1. A typical example of additive preparation is given in Example 1. Hydrocarbon "Core"

Cyanuric chloride is a very good example of a halogen containing reactive hydrocarbon "core" which can react with the disclosed aminoalcohols/amines to give product ethers/amines (Table 1, entries 2-7) . In addition, several combinations of the above ether/amine additives and pour point additive demonstrates improved cloud point and CFPP activity- (Table 1, entries 2, 5-7).

Other such suitable core structure include but are not limited to esters and ethers of cyanuric acid, halogenated alkanes (e.g. dichloromethane, trichloropropane, di- and tri-chloroadamantane) , halogenated aromatics (e.g. trichlorobenzene, dichloroanthracene, dichlorophenol, tetrachloropyrimidine, dichlorothiophene, trichlorofluorenone, and dichloropyridine) .

The reactions can be carried out under widely varying conditions which are not believed to be critical. The reaction temperatures can vary from 100 to 250°C or reflux, preferably 120 to 200°C, under ambient or autogenous pressure. However slightly higher pressures may be used if desired. The temperatures chosen will depend upon for the most part on the particular reactants and on whether or not a solvent is used. Solvents used will typically be hydrocarbon solvents such as xylene, but any non- polar, unreactive solvent can be used including benzene and toluene and/or mixtures thereof. By¬ products, such as HC1, may be removed from the reaction mixture via a suitable gas purge (such as nitrogen) or via in-situ scavenging of acidic by¬ products with added base (such as sodium hydroxide or sodium carbonate) .

The molar ratios of the reactants will vary widely dependent upon such variables as temperature, pressure, the specific reactants and the like and accordingly may vary from less than molar to more than molar to equimolar ratios. Preferentially a molar ratio of 1:1 to 10:1 of amine to epoxide is chosen and the preferred ratio of amine/epoxide/reactive halide may vary from 1/1/1 to 1/0.1/1, i.e. for each of the two or more reactive halides in the core group precursor.

The times for the reactions are also not believed to be critical. The process is generally carried out in from one to forty-eight hours or more.

In general, the reaction products of the present invention may be employed in any amount effective for imparting the desired degree of activity to improve the low temperature characteristics of distillate fuels. In many applications the products are effectively employed in amounts from 0.001% to 10% by weight and preferably from 0.01% to 5% of the total weight of the composition.

The fuels contemplated are liquid hydrocarbon combustion fuels, including the distillate fuels and fuel oils. Accordingly, the fuel oils that may be improved in accordance with the present invention are hydrocarbon fractions having an initial boiling point of at least 177°C (about 350°F) and an end-boiling point usually no higher than 399°C (about 750°F) and boiling substantially continuously throughout their distillation range. Such fuel oils are generally known as distillate fuel oils. It is to be understood, however, that this term is not restricted to straight run distillate fractions. The distillate fuel oils can be straight run distillate fuel oils, catalytically or thermally cracked (including hydrocracked) distillate fuel oils, or mixtures of straight run distillate fuel oils with cracked distillate stocks. Moreover, such fuel oils can be treated in accordance with well-known commercial methods, such as, acid or caustic treatment, hydrogenation, solvent refining, clay treatment, etc.

The distillate fuel oils are characterized by their relatively low viscosities, pour points, and the like. The principal property which characterizes the contemplated hydrocarbons, however, is the distillation range. As mentioned hereinbefore, this range will lie between 121°C (about 250°F) and 399°C (about 750°F) . Obviously, the distillation range of each individual fuel oil will cover a narrower boiling range falling, nevertheless, within the above-specified limits.

Contemplated among the fuel oils are Nos. 1, 2 and 3 fuel oils used in heating and as diesel fuel oils, and the jet combustion fuels. The domestic fuel oils generally conform to the specification set forth in A.S.T.M. Specifications D396-48T. Specifications for diesel fuels are defined in A.S.T.M. Specification D975-48T, Typical jet fuels are defined in Military Specification MIL-F-5624B. The following examples are illustrative only and are not intended to limit the scope of the invention.

EXAMPLES

EXAMPLE 1 Preparation of Additive Entry 1

Di(hydrogenated tallow) amine (56.1 g, 0.11 mol; e.g., Armeen 2HT from Akzo Chemie) , and 1,2- epoxyoctadecane (31.35 g, 0.11 mol; e.g., Vikolox 18 from Viking Chemical) were combined and heated at 190°C for 22 hours. Reaction temperature was lowered to 80-90°C, and both sodium hydroxide (18.13 g, 0.44 mol) and Aliquot 336 (0.15 g, 0.003 mol.) were added to the reaction mixture. Cyanuric chloride (6.97 g, 0.0366 mol; e.g., from Aldrich Chemical Co.) was added in portions at 80-90"C and heated at 110°C/20 hr. and then heated at 180°C/5 hr. Volatiles were removed from the reaction medium at 180°C, and the reaction mixture was hot filtered to give 56.4 g of the final product.

Examples 2 through 6 were prepared as in Example 1 but in differing molar ratios as set forth in the Table.

Preparation of Additive Concentrate

A concentrate solution of 100 ml total volume was prepared by dissolving 10 g of additive in mixed xylenes solvent. Any insoluble particulates in the additive concentrate were removed by filtration before use. Test Fuels

The test fuel used for the screening of additive activity had the following characteristics:

API Gravity 31.5

Cloud Point °C :, (°F) -5.9 (21.4)

CFPP °C, (°F) -10 (14)

Pour Point °C, ro -12 (10)

Distillation °C, D 86, (°F, D 86)

IBP (initial boiling point) 171 (340)

10% 226 (439)

50% 279 (534)

90% 338 (640)

FBP 367 (693)

Test Procedures

The cloud point of the additized distillate fuel was determined using an automatic cloud point test based on the commercially available Herzog cloud point tester; test cooling rate is approximately 1°C/min. Results of this test protocol correlate well with ASTM D2500 methods.

The low-temperature filterability was determined using the Cold Filter Plugging Point (CFPP) test. This test procedure is described in "Journal of the Institute of Petroleum," Vol. 52, No. 510, June 1966, pp. 173-185. TABLE: CORE/PENDANT GROUP ADDITIVES

Performance Improvement C° (°F)

& 200 PPM ECA 12513

Cloud Cloud t-t

Entry Pendant Group(s') Core Mole Ratio Point CFPP Point CFPP

Fuel; 500 ppm Additive

1 Armene 2HT/Vikolox 18 Cyanuric Chloride 3/3/1 -17.4 (0.7) -18.9 (-2) -16.6 (2.2) -14.4 (6)

2 Armene 2HT/Vikolox 18 Cyanuric Chloride 2/2/1 -16.2 (2.8) -15 (5) -16.6 (2.1) -16.7 (2)

3 Armene 2HT/Vikolox 18 Cyanuric Chloride 1.3/1.3/1 -16.1 (3.0) -16.7 (2) -16.7 (1.9) -16.7 (2)

4 Armene 2HT/Vikolox 18 Cyanuric Chloride 3/2/1 -17.1 (1.2) -17.8 (0) -16.5 (2.2) -17.8 (0)

5 Armene 2HT/Vikolox 18 Cyanuric Chloride 2.5/1.5/1 -17.6 (0.3) -17.8 (0) -16.9 (1.6) -16.7 (2)

6 Armene 2HT/Vikolox 18 Cyanuric Chloride 2/1/1 -17.0 (1.4) -16.7 (2) -16.6 (2.1) -14.4 (6)

The resultant test results clearly demonstrate the improved low-temperature characteristics of distillate fuels containing the ether type additives of the embodied invention.

Although the present invention has been described with preferred embodiments, it is to be understood that modifications and variations may be resorted to, without departing from the spirit and scope of this invention, as those skilled in the art will readily understand. Such variations and modifications are considered within the purview and scope of the appended claims.

Claims

CLAIMS :

1. A reaction product having a core-pendant group structure and formed by reacting a core selected from hydrocarbon groups containing two or more reactive halide groups, pseudo-halide groups and low molecular weight ethers with pendant groups selected from (1) an aminoalcohol comprising the product of an amine and an epoxide and (2) a combination of an aminoalcohol and a secondary amine.

2. The product of claim 1 wherein the aminoalcohol is derived from an epoxide and a secondary amine in the manner described below:

Where: R_, R_ = C to C_5Q linear hydrocarbyl groups, and R = C. to C hydrocarbyl.

3. The product of claim 2 wherein R and R are from C_ to C and R_ is from C to C_..

4. The product of claim 1 wherein the aminoalcohol is derived from di(hydrogenated tallow)amine and 1,2- epoxyoctadecane, and the core is cyanuric chloride.

5. A fuel composition comprising a major proportion of a liquid hydrocarbon fuel and a minor amount of the product of claim 1. 6. The fuel composition of claim 5 comprising from about 0.001% to 10% by weight of the total composition of the reaction product.

7. The fuel composition of claim 6 wherein R- and R_ are from C8-, to C2,-.4. and R_3 is from C1.2_ to C2„4..

8. The fuel composition of claim 5 wherein hydrocarbyl is selected from aromatic, alicyclic, aralkyl, alkylaryl and alkyl and corresponding heteroatom-containing analogues.

9. The fuel composition of claim 5 wherein the aminoalcohol is derived from di(hydrogenated tallow) amine and 1,2,-epoxyoctadecane, and the core is cyanuric chloride.

10. The composition of claim 5 wherein the fuel is a liquid hydrocarbon combustion fuel selected from distillate fuels and fuel oils.

11. The composition of claim 10 wherein the fuel oil is selected from fuel oil numbers 1, 2 and 3, diesel fuel oils and jet combustion fuels.

12. The composition of claim 10 wherein the fuel is a diesel fuel.

13. An additive concentrate comprising at least one inert liquid hydrocarbon solvent or mixture of solvents having dissolved therein the reaction product of claim 1. 14. The additive concentrate of claim 13 comprising a solution in which 10 grams of the product is dissolved in 100 ml of total volume.

15. The additive concentrate of claim 14 wherein the solvent is mixed xylenes solvent.