BRPI0814579B1 - METHOD FOR OPERATING A DIESEL ENGINE - Google Patents

Description

(54) Title: METHOD FOR OPERATING A DIESEL ENGINE (51) Int.CI .: C10M 129/10; C10M 133/12; C10M 169/04; C10N 30/10; C10N 40/25 (30) Unionist Priority: 07/23/2007 JP 2007-190658 (73) Holder (s): SHELL INTERNATIONALE RESEARCH MAATSCHAPPIJ B.V.

(72) Inventor (s): NORIAKI SHINODA; EIJI NAGATOMI "METHOD TO OPERATE A DIESEL ENGINE"

This invention relates to lubricating compositions for use in diesel engines that use biofuels.

In recent times, as a contribution to the reduction of

CO2 in the global environment, there was an increasing force to make positive use of fuels derived from vegetables and produced through biomass technologies. However, in composition, these are not necessarily similar to existing fossil fuels and thus several problems that can be generated by biofuels can be expected. Various investigations are being made of techniques to compete with these in the lubricating oils used in internal combustion engines.

In the case of alcohol fuels which are mainly used in the field of gasoline engines, mixing with water cannot be avoided, and the engine parts suffer a greater amount of wear than in the case of gasoline. Solutions to these problems have therefore been proposed. See Japanese Patent Open to the Public 5-70786 (1993).

Biofuels for use in diesel engines used in automotive vehicles in some cases were produced through the esterification of methyl from vegetable oils, mainly taking into account rapeseed oil or sunflower oil as its raw material in France, Germany , and Italy within the EU, and mainly soybean oil as its raw material in the United States. In many cases, these fuels are used by mixing about 20% in a clear oil.

There are several points about these biodiesel fuels that must be kept in mind when using them. These have aspects that need simple improvements in terms of fuel in which their viscosities of spill points are more properly high, and are prone to oxidize, and due to being derived from vegetable oils, they may contain many unsaturated fatty acids. In addition, these biodiesel fuels

Petition 870180002359, of 10/01/2018, p. 11/20 can compete directly with edible vegetable oils, and so they have not been studied as much as the aforementioned alcohol fuels as alternatives to gasoline, and there have rarely been attempts to improve lubricating oils in association with biodiesel fuels.

In the aforementioned diesel engines, because a mixture of biodiesel fuel and light oil is used, a phenomenon is seen whereby an unburned portion of the biodiesel fuel becomes mixed with the lubricating oil, promoting its aging. This creates difficulties for the use of lubricating oil in a stable manner for long periods.

The inventors have found that it is possible to inhibit aging, and in particular the degradation of the lubricant oil detergent performance, even after mixing with biodiesel fuel, combining different types of antioxidants, a phenolic antioxidant and an antioxidant based on amine, in the composition of lubricating oil.

For this purpose, the present invention provides a lubricating composition for use in diesel engines compatible with biofuel, the lubricating composition comprising a base oil that belongs to Group III and / or Group II of the API base oil categories, from 0, 5 to 5% by weight of a phenolic antioxidant and 0.5 to 5% by weight of an amine-based antioxidant, the total content of antioxidants being at least 2% by weight.

According to this invention, it is possible to inhibit the rapid degradation of detergent performance and the accelerated aging of the lubricating oil, even after mixing biodiesel fuel in the lubricating oil, using different types of antioxidants, a phenolic antioxidant and an antioxidant with amine-based together, and in this way it is possible to use the lubricating oil in a stable way for a long period.

Petition 870180002359, of 10/01/2018, p. 12/20

The light fuel oils and biodiesel oils used in automotive diesel engines, as already mentioned, have several obvious differences, and according to the literature (“New biomass liquid fuels for the 21st century”, published by Kagaku Kogyo Nippo [The

Chemical Daily] on April 25, 2002, teaching which is hereby incorporated by reference) can be summarized as the differences shown in Table 1.

Table 1

Biodiesel oil Light oil Spill point (° C) -5.5 -11.5 Kinetic viscosity (mm ² / s) 5.6 3.0 Instant vaporization point (° C) 135 ~ 145 88 Sulphur content (%) 0.0001 0.2 Carbon (%) 77.1 ~ 77.9 87.2 Hydrogen (%) 11.7 ~ 11.8 12.8 Oxygen (%) 11.1 ~ 11.2 0

As is evident from table 1, among the aspects where the 10 biodiesel oils differ substantially from light oils is the content of constituent oxygen atoms. It is also believed that, since these contain double bonds derived from unsaturated fatty acids, the combustion reaction differs by itself.

In addition, it can be mentioned that, in terms of physical properties, the instantaneous vaporization point is higher than in light oils and these are more likely to evaporate. When supplied as fuel to engines, the reaction can cease in the basic processes in order to complete combustion, and the unreacted portion will often mix with the lubricating oil or the unburned constituents will be mixed with the lubricating oil, causing sediment in the lubricating oil and accelerating the aging of the lubricating oil through oxidation.

Given these facts, lubricating oils will be characterized by being used under more stringent conditions even when exposed to high temperatures when using only light oils as fuel.

For the base oils of this invention it is possible to use any

Petition 870180002359, of 10/01/2018, p. 13/20 suitable mineral oil or synthetic oil, and it is usually possible to use base oils, alone or in mixtures, which belong to Group III and Group II of the API base oil categories (American Petroleum Institute).

These Group III and Group II base oils include, for example, paraffinic mineral oils obtained through a high degree of hydro-refining in relation to the lubricating oil fractions obtained through atmospheric distillation of crude oil, base oils refined by the Isodewax process. dewaxing and replaces the paraffin produced by the dewaxing process with isoparaffins, base oils refined by the Mobilwax isomerisation process, and the so-called solvent base oils devoid of wax (liquid gas) GTL or catalyst devoid of wax after synthesis by the method of Fischer-Tropsch. These also include those that can be designated as "synthetic oils" according to the rules of the NAD (National Advertising Division) which is responsible for publishing the awards in America.

The phenolic antioxidants and amine-based antioxidants are mixed together in these base oils.

As examples of these phenolic antioxidants mention may be made of 2,6-di-t-butylphenol, 2,6-di-t-butyl-p-cresol, 2,6-di-t-butyl-4-ethylphenol,

2,2 '-methylenobis (4-methyl-6-t-butylphenol), 2,2' -methylenobis (4-ethyl-6-tbutylphenol), 4,4'-bis (2,6-di-t-butylphenol) ), 4,4'-thiobis (6-t-butyl-o-cresol), and 3- (4-hydroxy-3,5-di-t-butylphenyl) propionic acid alkyl alcohol esters such as alcohol esters 3- (4-hydroxy-3,5-di-t-butylphenyl) propionic acid 6-methylmethyl.

Also, as examples of these amine-based antioxidants, mention may be made of diphenylamines, p, p'-dioctyldiphenylamines, p, p'-dinonyldiphenylamines, p, p'-didodecyldiphenylamines, phenyl-a-naphthylamines, p-octylphenyl -a-naphthylamines, p-nonylphenyl-anaphylamines and p-dodecylphenyl-αnaftilamines, and mixtures thereof.

Petition 870180002359, of 10/01/2018, p. 14/20

A preferred example of the aforementioned diphenylamines is a diphenylamine which is the reaction product of N-phenylbenzeneamine and 2,4,4-trimethylpentene.

The amount of the aforementioned phenolic antioxidant is 5 0.5 to 5.0% by weight based on the total amount of the lubricating oil composition, and preferably 0.5 to 2% by weight.

The amount of the above-mentioned amine-based antioxidant is 0.5 to 5.0% by weight based on the total amount of the lubricating oil composition, and preferably 0.5 to 2% by weight.

For both the phenolic antioxidant and the amine-based antioxidant mentioned above, if the amount is less than 0.5% by mass, oxidative stability decreases, which is undesirable, and if it exceeds 5% by mass the detergency of the piston decreases, which is often undesirable.

Phenolic antioxidants and amine-based antioxidants are used respectively in the amounts mentioned above, but it is also necessary that the total amount of the two antioxidants be at the same time not less than 2% by weight. If the total amount of both is less than that, the expected effect will not be achieved.

It is also possible to add to this composition of lubricating oil, as necessary, suitable dispersants, extreme pressure agents, detergents, viscosity index improvers and other additives.

In another aspect, the present invention provides a method of operating a diesel engine which comprises lubricating the diesel engine with a lubricating composition according to the present invention and using a biofuel, preferably derived from rapeseed oil, as a fuel.

Examples

Petition 870180002359, of 10/01/2018, p. 15/20

Biodiesel fuel (BDF) was a methyl ester derived from rapeseed oil and was prepared in order to have the properties shown in Table 2.

Table 2

Item Test Method Units Characteristic (numeric value) Density: Vibration method (15 ° C) JIS K-2249 g / cm ³ 0.883 Instant vaporization point: PMCC method JIS K-2265 ° C 155 Kinetic viscosity: 30 ° C JIS K-2283 mm ² / s 5.51 Cetane Value JIS K-2280 53.0

The following constituent materials were used in the preparation of the examples of the embodiment and comparative examples.

/ (1) Base oil: a mineral oil that belongs to Group III of

API (2) Phenolic antioxidant: ester of 6-methylethyl alcohol of 10 3- (4-hydroxy-3,5-di-t-butyl-phenyl) propionic acid (3) Amine-based antioxidant: diphenylamine being a product of reaction of N-phenylbenzenoamine and 2,4,4-trimethylpentene (4) Packaging of additives: additives containing dispersant, ZnDTP and detergent.

Examples 1 to 4, Comparative examples 1 to 6

Using the aforementioned constituent materials, the lubricating oil compositions of Examples 1 to 4 and Comparative Examples 1 to 6 were prepared according to Tables 3 and 4.

Comparative Example 6 mentioned above was a composition with a diesel engine oil combustion level DH-2 /

JASO (Standard Engine Oil Implementation Panel) for use in automotive vehicles.

The quantities of each constituent mixed in it are presented in each case as% by mass.

Tests

Petition 870180002359, of 10/01/2018, p. 16/20

In order to visualize the performance of the lubricating oil compositions of Examples 1 to 4 and Comparative Examples 1 to 6, hot tube tests (according to JPI-5S-55-99; a standard test from the Japanese Petroleum Institute to determine high temperature deposits) were carried out at 280 ° C under load conditions by means of which 5% by weight of biodiesel fuel was added with respect to 100% by weight of each lubricating oil composition.

The evaluation of the hot tube tests was 0 to 10 in fractions of 0.5, and 7 and above was adjusted as the approval mark.

Test results

The results are shown in Tables 3 and 4.

Table 3

Example 1 Example 2 Example 3 Example 4 Base oil 86 85 85.5 82 Phenolic antioxidant 1.0 1.5 1.5 2.0 Amine-based antioxidant 1.0 1.5 1.0 4.0 Packaging of additives 12 12 12 12 Total 100 100 100 100 Mixed BDF 5 5 5 5 Hot tube count 7.0 7.0 7.0 7.5

Table 4

Ex. Comp. 1 Ex. Comp. 2 Ex. Comp. 3 Ex. Comp. 4 Ex. Comp. 5 Ex. Comp. 6 Base oil 88 85.5 84.5 85.5 86.5 88 Phenolic antioxidant 2.5 0.5 Amine-based antioxidant 2.5 3.5 1.0 Packaging of additives 12 12 12 12 12 12 Total 100 100 100 100 100 100 Mixed BDF 5 5 5 5 5 Hot tube count 1.0 2.0 5.0 3.0 2.5 7.0

Evaluation

When using a phenolic antioxidant and an amine-based antioxidant together, as shown in Examples 1 to 4, the amount of each being no less than 1% by weight and the total amount being no less than 2% by weight. mass, a rating of 7 or higher was obtained in the hot tube test in all cases, and it was evident that

Petition 870180002359, of 10/01/2018, p. 17/20 these were lubricating oil compositions not prone to aging after mixing the biofuel.

Antioxidants were not added in the case of Comparative Example 1, and the hot tube count was insufficient, 1.0. The example

Comparative 2 used 2.5 wt% of the amine-based antioxidant alone, and although the total amount exceeded 2 wt%, the hot tube count was insufficient at 2.0. More amine-based antioxidant was added to Comparative Example 3 than Comparative Example 2, but the hot tube count only rises to 5.0. The example

Comparative Example 4 used 2.5 wt% of phenolic antioxidant alone, and although the total amount exceeded 2 wt%, the hot tube count was insufficient at 3.0. Comparative Example 5 used both antioxidants together, but the total amount was less than 2% by mass and so the hot tube count was insufficient at 2.5. A satisfactory effect was therefore not obtained for any of the Comparative Examples 1 to 5

Comparative Example 6 had no biofuel mixture, and although no phenolic antioxidants or amine based antioxidants were used, the hot tube count was 7.0 and it can be seen that a satisfactory effect was obtained.

Petition 870180002359, of 10/01/2018, p. 18/20

Claims (2)

1. Method for operating a diesel engine that comprises lubricating the diesel engine with a lubricating composition and using a biofuel as a fuel, characterized by the fact that the The lubricating composition comprises a base oil belonging to Group III and / or Group II of the API base oil categories, from 0.5 to 5% by weight of an ester of the 3- (4-hydroxy- 3,5-di-tbutylphenyl) propionic and from 0.5 to 5% by weight of a diphenylamine which is a reaction product of N-phenylbenzeneamine and 2,4,4-trimethylpentene, the content 10 total antioxidants being at least 2.5% by weight. 2. Method according to claim 1, characterized by the fact that the biofuel used in the diesel engine is derived from rapeseed oil. Petition 870180002359, of 10/01/2018, p. 19/20