FUELS DERIVED FROM ANIMAL OR VEGETABLE OIL SOURCES

Abstract

There is provided a method of providing an improved biofuel, by the presence of an additive which is the reaction product of (i) a compound containing the segment —NR.sup.1R.sup.2 where R.sup.1 represents a group containing from 4 to 44 carbon atoms and R.sup.2 represents a hydrogen atom or a group R.sup.1 (for example di-hydrogenated tallow amine) and (ii) a carboxylic acid having from 1 to 4 carboxylic acid groups or an acid anhydride or acid chloride thereof (for example phthalic acid or phthalic anhydride). The additives described combat problems arising from precipitation at temperatures above the cloud point.

Claims

1. A method of providing an improved Bx fuel, by the presence of an additive which is the reaction product of (i) a compound containing the segment —NR.sup.1R.sup.2 where R.sup.1 represents a group containing from 4 to 44 carbon atoms and R.sup.2 represents a hydrogen atom or a group 10, and (ii) a carboxylic acid, wherein the carboxylic acid is a benzene dicarboxylic acid selected from isophthalic acid, terephthalic acid and phthalic acid or an acid anhydride or acid halide thereof.

2. The method as claimed in claim 1, wherein the group R.sup.1 is a predominantly straight chain, substantially saturated group comprising from 10 to 24 carbon atoms.

3. The method as claimed in claim 1, in which the group R.sup.2 is a group containing from 4 to 44 carbon atoms or is a predominantly straight chain, substantially saturated group comprising from 10 to 24 carbon atoms.

4. The method as claimed in claim 3, in which the compound (i) is a secondary amine of formula HNR.sup.1R.sup.2 where R.sup.1 and R.sup.2 are as defined in claim 3; or is an ammonium salt having the cation +NR.sup.1R.sup.2R.sup.3R.sup.4 where R.sup.1 and R.sup.2 are as defined in claim 3 and R.sup.3 and R.sup.4 independently represent a C(1-4) alkyl group.

5.-6. (canceled)

7. The method as claimed in claim 1, in which the molar ratio of compound (i) to acid anhydride or acid halide (ii) is such that at least 50% of the acid groups are reacted in the reaction between the compounds (i) and (ii).

8. The method as claimed in claim 1, in which compound (i) is a secondary amine and/or quaternary ammonium salt and compound (ii) is a dicarboxylic acid, or an acid anhydride or acid halide thereof, wherein the molar ratio of compound(s) (i) to acid, acid anhydride or acid halide (ii) is at least 1:1.

9. The method as claimed in claim 1, wherein the said additive is present in the Bx fuel in an amount of from 5 mg/kg fuel to 500 mg/kg fuel.

10. The method as claimed in claim 1, in which the Bx fuel is a blended fuel comprising a fuel component derived from an animal or a vegetable oil source and a fuel component derived from a mineral source.

11. The method as claimed in claim 10, wherein the Bx fuel comprises one or more compounds which improve the flow properties of the fuel derived from the mineral source at a temperature below the cloud point of the Bx fuel.

12.-14. (canceled)

15. A Bx fuel having improved flow properties above the cloud point of the Bx fuel, the fuel comprising an additive which is the reaction product of (i) a compound containing the segment —NR.sup.1R.sup.2 where R.sup.1 represents a group containing from 4 to 44 carbon atoms and R.sup.2 represents a hydrogen atom or a group R.sup.1, and (ii) a carboxylic acid, wherein the carboxylic acid is a benzene dicarboxylic acid selected from isophthalic acid, terephthalic acid and phthalic acid or an acid anhydride or acid halide thereof.

16. An additive composition comprising an additive which is the reaction product of (i) a compound containing the segment —NR.sup.1R.sup.2 where R.sup.1 represents a group containing from 4 to 44 carbon atoms and R.sup.2 represents a hydrogen atom or a group R.sup.1, and (ii) a carboxylic acid, wherein the carboxylic acid is a benzene dicarboxylic acid selected from isophthalic acid, terephthalic acid and phthalic acid or an acid anhydride or acid halide thereof in a solvent.

17. The method as claimed in claim 1, in which the benzene dicarboxylic acid is phthalic acid or an acid anhydride or acid halide thereof.

18. The Bx fuel as claimed in claim 15, in which the benzene dicarboxylic acid is phthalic acid or an acid anhydride or acid halide thereof.

19. The additive composition as claimed in claim 16, in which the benzene dicarboxylic acid is phthalic acid or an acid anhydride or acid halide thereof.

20. The method as claimed in claim 1, wherein at least 75% of the acid groups are reacted in the reaction between the compounds (i) and (ii).

21. The method as claimed in claim 1, wherein at least 90% of the acid groups are reacted in the reaction between the compounds (i) and (ii).

22. The method as claimed in claim 1, wherein the molar ratio of compound(s) (i) to acid, acid anhydride or acid halide (ii) is at least 1.5:1.

23. The method as claimed in claim 1, wherein the said additive is present in the Bx fuel in an amount of from 10 mg/kg fuel to 80 mg/kg fuel.

24. The method as claimed in claim 1, wherein the said additive is present in the Bx fuel in an amount of from 20 mg/kg fuel to 60 mg/kg fuel.

25. The method as claimed in claim 1, wherein the said additive is present in the Bx fuel in an amount of from 30 mg/kg fuel to 45 mg/kg fuel.

26. The method as claimed in claim 1, in which the Bx fuel is a blended fuel comprising a fuel component derived from a vegetable oil source and a fuel component derived from a mineral source.

Description

EXAMPLE SET A

[0089] The tests involved using a modified version of the IP387 (Determination of filter blocking tendency of gas oils and distillate diesel fuels) method.

[0090] In the IP 387 method, a sample of the fuel to be tested is passed at a constant rate of flow through a glass fibre filter medium. The pressure drop across the filter is monitored, and the volume of fuel passing the filter medium within a prescribed pressure drop is measured.

[0091] The filter blocking tendency (FBT) can be described in one of the following ways: [0092] The pressure drop (P) across a GF/A (glass fibre) filter medium for 300 ml of fuel to pass at a rate of 20 ml/min is recorded. [0093] The volume of fuel (v) passed when a pressure of 105 kPa is reached. This method of report is used when less than 300 ml passes at that pressure drop.

[0094] The FBT may be expressed on a single scale by combining these using the following formulae

[00001]$\mathrm{FBT}=\sqrt{1+{\left(\frac{P}{105}\right)}^2}\mathrm{and}\mathrm{FBT}=\sqrt{1+{\left(\frac{300}{V}\right)}^2}$

[0095] Thus when exactly 300 ml passes through the filter at a pressure of 105 kPa, the FBT is 1.41. Values of FBT >1.41 indicate that less than 300 ml pass through the filter before a pressure of 105 kPa is reached. Values of FBT <1.41 indicate that 300 ml pass through the filter at a pressure of less than 105 kPa

[0096] An FBT <1.4 is considered to be a good result.

[0097] The modification to the IP 387 method relates to thermal conditioning and cold soak of a sample being tested. [0098] 1. the sample is heated to a temperature of 60° C. for 3 hours and then allowed to cool to 20° C. [0099] 2. The sample is then cooled to 5° C. for 16 hours and then allowed to warm to room temperature.

[0100] Following this conditioning, the Filter Blocking Tendency is determined using IP 387.

[0101] The base fuel used in these tests was a B5 fuel which met the requirements of DIN EN 590 and contained a commercially available cold flow additive believed to comprise EVA copolymers in an amount effective to achieve a CFPP of <−15° C. The fuel had the following properties:

TABLE-US-00001 Method Method Number Result Density at IP 365 0.8417g/ml 15° C. CFPP IP 309   −17° C. Cloud Point ASTM D5772  −5.8° C. Distillation IP 123 IBP 175.5° C.  5% 195.9° C. 10% 206.4° C. 20% 226.0° C. 30% 244.0° C. 40% 260.5° C. 50% 275.0° C. 60% 288.7° C. 70% 302.3° C. 80% 317.2° C. 90% 335.3° C. 95% 348.6° C. FBP 359.5° C.

[0102] Testing was carried out using

[0103] a) this base fuel,

[0104] b) this base fuel additised with 37.5 mg/kg of Compound A, and

[0105] c) this base fuel additised with a commercial WASA (believed to be a nitrogen-containing polymeric WASA) long used with success to improve the flow properties of mineral diesel fuels below the cloud point.

[0106] To prepare Compound A phthalic anhydride (7.4 g) was mixed with di (hydrogenated tallow) amine (Commercially available as Armeen 2HT) (50.02 g) at a molar ration of 1:2 in Shellsol AB solvent (57.5 g). The reaction mixture was heated at 65° C. for approximately 6 hours.

[0107] The results are as follows:

TABLE-US-00002 (b) base fuel + (c) base fuel + 37.5 mg/kg 150 mg/kg Sample (a) base fuel Compound A WASA Filter Blocking 1.8 1.23 1.87 Tendency Initial pressure 10 10 10 (kPa) Final pressure 105 75 105 (kPa) Volume filtered 200 300 190 (ml) Test temperature 23 23 23 (° C.)

[0108] Using Compound A allowed all 300 ml of the fuel to pass through the filter without the pressure reaching 105 kPa. The improvement over the performance of the base fuel is very marked. In contrast it is observed that the commercial WASA, at a higher treat rate, causes no discernable improvement in the flow properties of the base fuel.

EXAMPLE SET B

[0109] In Example Set B the testing was the same as in Example Set A but the base fuel (“Basefuel 2”) also met the requirements of DIN EN90 and was a B10 fuel prepared from a standard diesel meeting the specifications of CEC Fuel Specification RF-06-03, blended with rapeseed methyl ester (RME) and a commercially available cold flow additive believed to comprise EVA copolymers in an amount effective to achieve a CFPP of <−15° C.

[0110] The FBT of Basefuel 2 was 2.52.

[0111] The FBT of Basefuel 2 additised with 37.5 mg/kg of Compound A was 1.03.

[0112] The FBT of Basefuel 2 additised with 150 mg/kg of WASA (believed to be a nitrogen-containing polymeric WASA) was 2.03.