Use of a complex ester to reduce fuel consumption

Abstract

The use of a complex ester obtainable by esterification reaction between aliphatic linear or branched C.sub.2- to C.sub.12-dicarboxylic acids, aliphatic linear or branched polyhydroxy alcohols with 3 to 6 hydroxyl groups, and, as chain stopping agents, aliphatic linear or branched C.sub.1- to C.sub.30-monocarboxylic acids or aliphatic linear or branched monobasic C.sub.1- to C.sub.30-alcohols, as an additive in a fuel for minimization of power loss in the operation of an internal combustion engine with this fuel.

Claims

1. A method of minimizing power loss in the operation of an internal combustion engine, consisting of: adding to a fuel a complex ester obtained by an esterification reaction between (A) at least one aliphatic linear or branched C.sub.2- to C.sub.12-dicarboxylic acid, (B) at least one aliphatic linear or branched polyhydroxy alcohol with 3 to 6 hydroxyl groups, and (C) as a chain stopping agent (C1) at least one aliphatic linear or branched C.sub.1- to C.sub.30-monocarboxylic acid in case of an excess of component (B), or (C2) at least one aliphatic linear or branched monobasic C.sub.1- to C.sub.30-alcohol in case of an excess of component (A).

2. The method of claim 1, wherein component (A) is at least one member selected from the group consisting of aliphatic linear C.sub.6- to C.sub.10-dicarboxylic acids.

3. The method of claim 1, wherein component (B) is at least one member selected from the group consisting of glycerin, trimethylolpropane and pentaerythritol.

4. The method of claim 1, wherein component (C) is at least one member selected from the group consisting of (C1) aliphatic linear or branched C.sub.8- to C.sub.18-monocarboxylic acids, and (C2) linear or branched C.sub.8- to C.sub.18-alkanols.

5. The method of claim 1, wherein the complex ester is composed of from 2 to 9 molecule units of component (A) and of from 3 to 10 molecule units of component (B), component (B) being in excess compared with component (A), with remaining free hydroxyl groups of (B) being completely or partly capped with a corresponding number of molecule units of component (C1).

6. The method of claim 1, wherein the complex ester is composed of from 3 to 10 molecule units of component (A) and of from 2 to 9 molecule units of component (B), component (A) being in excess compared with component (B), with remaining free carboxyl groups of (A) being completely or partly capped with a corresponding number of molecule units of component (C2).

Description

EXAMPLES

(1) All complex esters of the following examples were prepared according to the teachings of WO 99/16849, more precisely according to the general procedure as follows:

(2) The ratio of all three components, i.e. of mono fatty acids, of dicarboxylic acids or dimeric acids, respectively (together diacids), and of triols, was choosen in a way that OH and COOH groups were present in equimolar amounts. All reactants were added to the reactor and heated to approximately 140 C. Then, the temperature was stepwise increased to a maximum temperature of approximately 250 C. until the acid number was below 5 mg KOH/g. In case a tin catalyst was necessary to reach this level of residual acid number, the catalyst was removed by filtration.

(3) The following table shows the composition of the complex esters prepared (Examples 1a, 1b and 1c are for comparison, Examples 2 and 3 are according to the present invention):

(4) TABLE-US-00001 mono fatty acid diacid Triol Example 1a oleic acid dimeric tallow fatty acid trimethylol- (comparison) (18 wt. % in the complex propane ester) Example 1b oleic acid dimeric tallow fatty acid trimethylol- (comparison) (6 wt. % in the complex propane ester) Example 1c oleic acid dimeric tallow fatty acid trimethylol- (comparison) (39 wt. % in the complex propane ester) Example 2 isostearic sebacic acid pentaerythrol (invention) acid (15 wt. % in the complex ester) Example 3 C.sub.8-C.sub.10 acid adipinic acid trimethylol- (invention) (13 wt. % in the complex propane ester)

Example 4: Preparation of Gasoline Performance Package GPP 1

(5) 150 mg/kg of the complex ester of Example 1a, 1b, 1c, 2 or 3 above were mixed with a customary gasoline performance package containing as detergent additive component Kerocom PIBA (a polyisobutene monoamine made by BASF SE, based on a poly-isobutene with M.sub.n=1000) and usual polyether-based carrier oils, Solvent Naphtha as a diluent and corrosion inhibitors in customary amounts.

Example 5: Engine Cleanliness Tests with GPP 1

(6) In order to demonstrate that the complex esters according to the present invention of Examples 2 and 3 do not decrease engine cleanliness and that the complex esters of the art of Example 1 exhibit worse performance, the average IVD values were deter-mined with gasoline performance package of Example 4 (GPP 1) and, for comparison, with the same gasoline performance package (GPP 1) with the customary detergent additive component Kerocom PIBA but without any complex ester, each according to CEC F-20-98 with a Mercedes Benz M111 E engine using a customary RON 95 E10 gasoline fuel and a customary RL-223/5 engine oil. The following table shows the results of the determinations:

(7) TABLE-US-00002 average IVD Additive [mg/valve] GPP 1 without any complex ester 12 GPP 1 with 150 mg/kg of Example 1a 29 GPP 1 with 150 mg/kg of Example 1b 21 GPP 1 with 150 mg/kg of Example 1c 166 GPP 1 with 150 mg/kg of Example 2 9 GPP 1 with 150 mg/kg of Example 3 6

Example 6: Fuel Economy Tests

(8) A typical low sulphur US E10 gasoline was additized with the gasoline performance package of Example 4 (GGP 1) containing 150 mg/kg the complex ester of Example 2 or 3, respectively, and used to determine fuel economy in a fleet test with three different automobiles according to U.S. Environmental Protection Agency Test Protocol, C.F.R. Title 40, Part 600, Subpart B. For each automobile, the fuel consumption was determined first with unadditized fuel and then with the same fuel which now, however, comprised the above-specified gasoline performance package in the dosage as specified above. The following fuel savings were achieved: 2004 Mazda 3, 2.0 L I4: 1.03% (with Example 2); 0.75% (with Example 3) 2012 Honda Civic, 1.8 L I4. 1.02% (with Example 2); 1.32% (with Example 3) 2010 Chevy HHR, 2.2 L I4: 1.53% (with Example 2); 1.55% (with Example 3)

(9) On average, over all automobiles used, the result was an average fuel saving of 1.19% (with Example 2) and 1.21% (with Example 3).

Example 7: Preparation of Gasoline Performance Package GPP 2

(10) 150 mg/kg of the complex ester of Example 2 or 3, respectively, above were mixed with a customary gasoline performance package containing as detergent additive component Kerocom PIBA (a polyisobutene monoamine made by BASF SE, based on a poly-isobutene with M.sub.n=1000) and usual polyether-based carrier oils, kerosene as a diluent, demulsifiers and corrosion inhibitors in customary amounts.

Example 8: Storage Stability

(11) 48.0% by weight of GPP 2 above containing complex ester of Example 2 or 3, respectively, and 37.7% by weight of xylene were mixed at 20 C. and stored thereafter in a sealed glass bottle at 20 C. for 42 days. At the beginning of this storage period and then after each 7 days, the mixture was evaluated visually and checked for possible phase separation and precipitation. It is the aim that the mixture remains clear (c), homogeneous (h) and liquid (l) after storage and does not exhibit any phase separation (ps) or precipitation (pr). The following table shows the results of the evaluations:

(12) TABLE-US-00003 after 7 days c, h, l (for Example 2) c, h, l (for Example 3) after 14 days c, h, l (for Example 2) c, h, l (for Example 3) after 21 days c, h, l (for Example 2) c, h, l (for Example 3) after 28 days c, h, l (for Example 2) c, h, l (for Example 3) after 35 days c, h, l (for Example 2) c, h, l (for Example 3) after 42 days c, h, l (for Example 2) c, h, l (for Example 3) Result: pass (for Example 2) pass (for Example 3)