KR20150006793A - Marine engine lubrication - Google Patents

Abstract

A detergent system that includes (i) an overbased C20-28 alkyl-substituted hydroxybenzoate Ca salt of TBN less than 250 and (ii) an overbased C14-18 alkyl-substituted hydroxybenzoate Ca salt of TBN less than 250, the wt % Ca ratio of (ii) to (i) being more than one, is used in a trunk piston marine lubricant to improve its asphaltene dispersancy when lubricating a medium-speed compression-ignited marine engine fuelled by a heavy fuel oil.

Description

Marine engine lubrication {MARINE ENGINE LUBRICATION}

The present invention relates to a method for improving asphaltene dispersancy of a trunk piston marine engine.

The present invention also relates to the use of a detergent system for improving the asphaltene dispersibility of a trunk piston marine engine.

The present invention also relates to a detergent system comprising a combination of hydroxybenzoates in a trunk piston marine engine lubricating composition for a medium-speed four stroke compression-ignition (diesel) marine engine, wherein the asphaltene dispersion And to improve the performance.

Ship trunk piston engines typically use heavy fuel oil (HFO) for offshore operations. Heavy fuel oil is the heaviest fraction of petroleum distillates and contains 15% or less asphaltene, defined as a fraction of petroleum distillate which is insoluble in excess aliphatic hydrocarbons (e.g., heptane) but soluble in aromatic solvents (such as toluene) ≪ / RTI > Asphalten can enter the engine lubricant as a contaminant via a cylinder or a fuel pump and an injector and then produce an asphaltene precipitate that appears in the engine as a "black paint" or "black sludge". The presence of such a carbonaceous deposit on the piston surface can serve as an insulating layer, which can later form cracks propagating through the piston. When the crack moves through the piston, the hot combustion gas enters the crankcase, possibly causing a crankcase explosion.

Therefore, trunk piston engine oil (TPEO) is highly desirable to prevent or inhibit asphaltene precipitation.

EP-B-1992 678 describes a trunk piston engine oil containing a combination of overbased alkylsalicylic acid calcium salts to improve wear characteristics.

It has now been found that improved asphaltene dispersion characteristics can be achieved by using certain hydroxybenzoate combinations in TPEO.

(I) an overbased alkyl-substituted hydroxybenzoate calcium salt of TBN of less than 250, wherein the alkyl group has from 20 to 28 carbon atoms, and (ii) an alkyl group having from 14 to 18 A lubricant composition comprising a cleansing system having an overbased alkyl-substituted hydroxybenzoate calcium salt having a carbon atom and a TBN of less than 250, wherein the weight% Ca ratio of (ii) to (i) And lubricating the engine with the engine. ≪ RTI ID = 0.0 > [0002] < / RTI >

A second aspect of the present invention relates to a method of lubricating a trunk piston ship lubricating oil composition for medium speed compression-ignition marine engine, in operation of an engine, comprising the steps of: (i) introducing an overbased alkyl group having an alkyl group of 20 to 28 carbon atoms, Substituted hydroxybenzoate calcium salt, and (ii) an overbased alkyl-substituted hydroxybenzoate calcium salt of TBN of less than 250, wherein the alkyl group has from 14 to 18 carbon atoms, , wherein the weight% Ca ratio of (ii) to (i) is greater than 1, said use is for improving the asphaltene dispersibility of the composition.

A third aspect of the present invention relates to a trunk piston vessel lubricating oil composition for medium speed compression-ignition marine engines, comprising: (i) an alkyl group having from 20 to 28 carbon atoms, (Ii) an overbased alkyl-substituted hydrolyzate of TBN of less than 250, wherein the alkyl group has from 14 to 18 carbon atoms, wherein the overbased alkyl-substituted hydroxybenzoate calcium salt comprises less than 250 TBN of an overbased alkyl-substituted hydroxybenzoate calcium salt; Wherein the weight% Ca ratio is greater than or equal to 1 and / or wherein the weight% Ca ratio of (ii) to (i) is greater than 1. The use of a detergent system, ) Is to improve the asphaltene dispersibility of the composition as compared to similar operations using a detergent system having a TBN of 250 or greater.

In the following description, when the following terms and expressions are used, they have the following meanings.

The term " active ingredient "or" a. I. &Quot; refers to an additive that is not a diluent or solvent.

The term " comprising "or like terms specifically designates the presence of stated features, steps, integers or components, but does not preclude the presence or addition of one or more other features, steps, integers, components or groups. The term " consisting essentially of, "or " consisting essentially of, " or similar terms may be included within the scope of" comprising "or the like, wherein" consisting essentially of " Allows substances that do not give rise to be incorporated.

The term "major amount" means at least 50%, preferably at least 40%, more preferably at least 30% by weight of the composition.

The term "minor amount" means less than 50 wt%, preferably less than 40 wt%, more preferably less than 30 wt% of the composition.

The term "TBN" means the total base number measured by ASTM D2896.

In addition, as used herein,

The "calcium content" is measured by ASTM 4951,

The "phosphorus content" is measured by ASTM D5185,

The "sulphated ash content" is measured by ASTM D874,

The "sulfur content" is measured by ASTM D2622,

"KV100" means the kinematic viscosity at 100 DEG C measured by ASTM D445.

In addition, not only essential but also various components which are optimally and conventionally used can be reacted under the conditions of compounding, storage or use, and the present invention also provides a product which can be obtained or obtained by any of these reactions Of course.

It is also understood that any upper limit and lower limit quantities, ranges, and ratios described herein can be combined independently.

The features of the present invention will be discussed in more detail below.

Lubricating viscosity oil

The trunk piston marine lubricating oil composition of the present invention comprises a major amount of lubricating viscous oil. The oil may have a viscosity range from the hard distillate inorganic flow path to the heavy lubricant. The oil may be referred to as base oil. Generally, the viscosity of the oil ranges from 2 to 40 mm 2 / sec as measured at 100 ° C. The oil may be natural oil or synthetic unique.

Natural oils include animal and vegetable oils (e.g., castor oil, lard oil); Liquid petroleum oil and hydrogenated refined, solvent-treated, or acid-treated paraffinic, naphthenic and mixed paraffin-naphthenic type mineral oils. Also, lubricating viscous oils derived from coal or shale may be used.

Synthetic lubricating oils include hydrocarbon oils and halo-substituted hydrocarbon oils such as polymerized and interpolymerized olefins such as polybutylene, polypropylene, propylene-isobutylene copolymer, chlorinated polybutylene, poly (1- Hexene), poly (1-octene), poly (1-decene); Alkylbenzenes (e.g., dodecylbenzene, tetradecylbenzene, dynonylbenzene, di (2-ethylhexyl) benzene); Polyphenyls (e.g., biphenyl, terphenyl, alkylated polyphenols); And alkylated diphenyl ethers and alkylated diphenyl sulfides, and derivatives, analogs, and analogs thereof.

Alkylene oxide polymers, in which the terminal hydroxyl groups are modified by esterification, etherification, etc., and their interpolymers and derivatives, constitute another class of known synthetic lubricating oils. These include polyoxyalkylene polymers prepared by polymerization of ethylene oxide or propylene oxide, and alkyl and aryl ethers of polyoxyalkylene polymers (e.g., methyl-polyiso-propylene glycol ether having a molecular weight of 1000, ≪ / RTI > 1500 polyethylene glycol); And their mono- and polycarboxylic acid esters, such as the acetic acid esters of tetraethylene glycol, mixed C ₃ -C ₈ fatty acid esters and C ₁₃ oxo acid diesters.

Other suitable classes of synthetic lubricating oils include dicarboxylic acids such as phthalic acid, succinic acid, alkyl succinic acid and alkenyl succinic acid, maleic acid, azelaic acid, suberic acid, sebacic acid, fumaric acid, adipic acid, linoleic acid, (Meth) acrylates of various alcohols (e.g., butyl alcohol, hexyl alcohol, dodecyl alcohol, 2-ethylhexyl alcohol, ethylene glycol, diethylene glycol monoether, propylene glycol) Ester. ≪ / RTI > Specific examples of such esters include dibutyl adipate, di (2-ethylhexyl) sebacate, di-n-hexyl fumarate, dioctyl sebacate, diisooctyl azelate, diisodecyl azelate, dioctyl phthalate, Ethylhexyl diester of linoleic acid dimer, and complex esters formed by the reaction of 1 mole of sebacic acid with 2 moles of tetraethylene glycol and 2 moles of 2-ethylhexanoic acid. .

Esters useful as synthetic oils also include those prepared from C ₅ to C ₁₂ monocarboxylic acids and polyols such as neopentyl glycol, trimethylol propane, pentaerythritol, dipentaerythritol and tripentaerythritol.

Siliceous oils (e.g., polyalkyl-, polyaryl-, polyalkoxy-, or polyaryloxy silicone oil) and silicate oils include another useful class of synthetic oils, such as tetraethyl silicate, tetraisopropyl silicate , Tetra- (2-ethylhexyl) silicate, tetra- (4-methyl-2-ethylhexyl) silicate, tetra- ) Di-siloxane, poly (methyl) siloxane, and poly (methylphenyl) siloxane. Other synthetic lubricating oils include liquid esters of phosphorus-containing acids (e.g., tricresyl phosphate, trioctyl phosphate, diethyl ester of decyl phosphonic acid) and polymeric tetrahydrofuran.

Unrefined, refined and re-refined oils can be used in the lubricants of the present invention. Unrefined oils are those obtained directly from natural or synthetic sources without further purification treatment. For example, shale oil obtained directly from a retorting operation, oil obtained directly from distillation, or an ester oil obtained directly from esterification and used without further treatment is an unrefined oil. Purified oils are similar to unrefined oils, except that the oil is further treated in one or more purification steps to improve one or more characteristics. Many such purification techniques such as distillation, solvent extraction, acid or base extraction, filtration and permeation are known to those skilled in the art. The re-refined oil is obtained by a process similar to the process used to provide the refined oil, but is undertaken with the used oil already in service. Such re-refined oils are also known as regenerated or reprocessed oils and are often further processed using techniques for removing waste additives and oil degradation products.

The Institute of Petroleum Engineers ("API Oil"), Industry Services Department, Fourteenth Edition, December 1996, Addendum 1, December 1998, categorizes base stocks as follows:

a) Group I base stocks contain less than 90% saturates and / or greater than 0.03% sulfur and, when using the test method specified in Table E-1, have a viscosity index of greater than 80 and less than 120.

b) Group II base stocks contain not less than 90% saturates and not more than 0.03% sulfur and, when using the test method specified in Table E-1, have a viscosity index of not less than 80 and not more than 120.

c) Group III base stocks contain at least 90% saturates and up to 0.03% sulfur and have a viscosity index of 120 or greater when using the test method specified in Table E-1.

d) Group IV base stock is polyalphaolefin (PAO).

e) Group V base stock includes all other base stock not included in Group I, II, III or IV.

The analytical methods for base stocks are listed in the table below (Table E-1).

For example, the present invention includes base stocks derived from hydrocarbons comprising Groups II, III and IV base stock and also synthesized by the Fischer-Tropsch process. In the Fischer-Tropsch process, syngas (or 'syngas') containing carbon monoxide and hydrogen is first generated and then converted to hydrocarbons using a Fischer-Tropsch catalyst. Such hydrocarbons typically require further processing in order to be useful as a base oil. For example, it can be hydroisomerized by methods known in the art; Hydrocracked and hydrogenated isomerization; Dewaxed; Or hydrogen isomerization and dehydration. The syngas can be produced, for example, from a gas such as natural gas or other gaseous hydrocarbons by steam reforming if the resulting base stock can be referred to as a gas-to-liquid or "GTL" From the gasification of the biomass if the resulting base stock can be referred to as a biomass-to-liquid or "BTL" or "BMTL" base oil; Or from the gasification of coal if the resulting base stock can be referred to as a coal-to-liquid or "CTL " base oil.

Preferably, the lubricating viscosity oil of the present invention contains at least 50% by weight of a base stock or mixture thereof containing not less than 90% saturates and not more than 0.03% sulfur. Preferably, it contains at least 60% by weight, such as 70, 80 or 90% by weight, of the above defined base stock or mixtures thereof. The lubricating viscous oil may be substantially any of the above defined base stocks or mixtures thereof.

The composition may have a TBN in the range of 20 to 60, preferably 25 to 55.

Detergent system

Metal cleaners are additives based on the so-called metal "soap ", i.e. metal salts of acidic organic compounds, sometimes referred to as surfactants. These typically include a polar head with a long hydrophobic tail. An overbased metal cleanser comprising a neutralized metal detergent as an outer layer of a metal base (e.g., carbonate) micelle can be prepared by reacting an excess of a metal base, such as an oxide or hydroxide, with an acidic gas, such as carbon dioxide, Can be provided.

In the present invention, the detergents (i) and (ii) of the present invention are an overbased alkyl-substituted hydroxybenzoate calcium salt, preferably an alkyl-substituted salicylate calcium salt.

Salicylate cleaners in such systems have the following structure:

Wherein R is a linear alkyl group.

There may be more than one R group attached to the benzene ring. The COO ^- group may be in the ortho, meta or para position relative to the hydroxyl group, with the ortho position being preferred. The R group may be in the ortho, meta or para position relative to the hydroxyl group.

(i), R has from 20 to 28, preferably from 20 to 24 carbon atoms. (ii), R has from 14 to 18 carbon atoms. (i) and (ii) may each be a mixture.

Salicylic acid is typically prepared by the carboxylation of the phenoxide by the Kolbe-Schmitt process, in which case it will generally be obtained (typically as a diluent) with the non-carboxylated phenol. Salicylic acid can be non-sulfated or sulfated, chemically modified and / or contain additional substituents. Processes for sulfating alkylsalicylic acid are known to those skilled in the art and are described, for example, in US 2007/0027057.

The term " overbased "is generally used to describe a metal detergent wherein the ratio of the number of equivalents of metal residues to the number of equivalents of acid residues is greater than one. The term "low-basic" is used to describe a metal detergent having an equivalence ratio of metal residues to acid residues of more than 1 and less than or equal to about 2.

The basicity of the detergent can be expressed as the total base (TBN). The total base number is the amount of acid required to neutralize the entire basicity of the overbased base material. TBN can be measured using ASTM standard D2896 or equivalent procedure. The detergent, as mentioned above, has a TBN of less than or equal to 250 each, for example in the range of 60 to 250, preferably 150 to 250.

The weight% Ca ratio of (ii) to (i) is, as mentioned, greater than 1, for example from 1 to 50, preferably from 1 to 3. [

The throughput of the detergent system (A) contained in the lubricating oil composition may range, for example, from 1 to 25, preferably from 2 to 20, and more preferably from 5 to 18 wt%.

Co-additive

The lubricating oil composition of the present invention may further comprise additives other than the detergent system, in addition to the detergent system. Such additional additives may include, for example, ashless dispersants, other metal cleaners, antiwear agents such as zinc dihydrocarbyl dithiophosphate, antioxidants and anti-fogging agents. In some cases, no ashless dispersant need be provided.

Although not required, it may be desirable to produce one or more additive packages or concentrates containing additives, wherein the detergent system may be added to the base oil simultaneously to form a lubricating oil composition. The dissolution of the additive package into the lubricating oil may be facilitated by solvent and by mixing accompanied by mild heating, but this is not essential. When the additive package is combined with a predetermined amount of base oil, such an additive package is typically formulated to contain an appropriate amount of the additive (s) to provide the desired concentration and / or to perform the intended function in the final composition. Thus, the detergent system according to the present invention may be mixed with minor amounts of base oil or other compatible solvent along with other desirable additives to provide 2.5 to 90% by weight, preferably 5 to 90% by weight, of the additive, for example, 75% by weight, most preferably 8-60% by weight of the active ingredient, with the balance being base oil.

The final composition as trunk piston engine oil typically contains 30 wt.%, Preferably 10 to 28 wt.%, More preferably 12 to 24 wt.% Of the additive package, with the balance being base oil.

The invention is illustrated by the following examples, which are not intended to be limiting in any way.

Example

ingredient

The following ingredients were used.

Cleaner (ii):

A: A calcium alkyl salicylate detergent of TBN 225 wherein the alkyl group has 14 to 18 carbon atoms.

B: A calcium alkyl salicylate detergent of TBN 350 wherein the alkyl group has 14 to 18 carbon atoms.

C: Calcium alkyl salicylate detergent of TBN 64 wherein the alkyl group has from 14 to 18 carbon atoms.

Detergent (i): Calcium alkyl salicylate detergent of TBN 223 wherein the alkyl group has 20 to 24 carbon atoms.

Base oil I: solvent - extracted API Group I base oil.

HFO: Heavy fuel oil (ISO-F-RMK 380).

slush

The components were selected and blended to provide a range of trunk piston marine engine lubricants. Some of these lubricants are embodiments of the present invention and others are control examples for comparison purposes. The composition of the tested lubricant is shown in the table below under the heading "Results ". Each lubricant had a TBN of about 40. Each lubricant also contained an equal amount of HFO.

exam

Light scattering

The test lubricant was evaluated for asphaltene dispersibility using light scattering according to the Focused Beam Reflectance Method (FBRM), which predicts asphaltene agglomeration and thus "black sludge" formation.

The FBRM test method was presented at the 7th International Symposium on Ship Engineering in Tokyo from October 24 to 28, 2005, and published as a conference bulletin in The Benifits of Salicylate Detergents in TPEO Application with a Variety of Base Stocks Was published. Further details were published at the CIMAC meeting in Vienna on 21-24 May 2007 and published as a conference newsletter as "Meeting the Challenge of New Base Fluids for the Lubrication of Medium Speed Marine Engines - An Additive Approach" . In the latter article, the FBRM method is used to quantitatively evaluate the performance of the asphaltene dispersant, predicting performance for a lubricant system based on basestocks containing greater than or less than 90% saturation and greater than or equal to 0.03% sulfur. Results can be obtained. Prediction of relative performance from FBRM was confirmed by engine testing on marine diesel engines.

The FBRM probe contains a fiber optic cable that moves the laser light to reach the probe tip. In the tip, the lens focuses the laser light to a small point. The lens is rotated to scan the focussed beam for a circular path between the probe window and the sample. As the particles flow past the window, they cross the scanning path and provide backscattered light from the individual particles.

The scanning laser beam travels much faster than the particles, which means that the particles are effective stationary. As the focusing beam reaches one edge of the particle, the amount of backscattered light increases, and the amount will decrease as the focusing beam reaches the other edge of the particle.

The instrument measures the time of increased backscattering. The result of multiplying the time of backscattering from one particle with the scan rate is the distance or chord length. The string length is a straight line between any two points at the edge of the particle. This is represented as a graph of the number of string lengths (particles) measured as a function of the string length distribution, i. E., A function of the string length dimension in microns. As measured in real time, distribution statistics can be calculated and tracked. Typically, the FBRM measures tens of thousands of strings per second, producing a powerful [number x string length] distribution. This method provides an absolute measure of the particle size distribution of the aspartic particles.

The Focus Beam Reflectance Probes (FBRM) and the Model Lasentec D600L are supplied by Mettler Toledo, Leicester, UK. The instrument was configured to provide particle size resolution of 1 [mu] m to 1 mm. Data from the FBRM can be presented in several ways. There has been research suggesting that the average count per second can be used as a quantitative determinant of asphaltene dispersion. This value is a function of both the average size and the level of aggregate. In this application, the average count rate (over the entire size range) was monitored using a measurement time of 1 second per sample.

The test lubricant formulation was heated to 60 DEG C and stirred at 400 rpm. When the temperature reached 60 ° C, the FBRM probe was placed in the sample. Heavy fuel oil aliquots (10% w / w) were introduced into the lubricant composition under stirring (400 rpm) using a four-bladed stirrer. The average count value per second was taken when the count rate reached an equilibrium value (typically after 30 minutes).

result

Light scattering

The FBRM test results are summarized in Table 1 below (where lower particle counts indicate better performance).

Example 1 is an example of the present invention, and Examples A to F are comparative examples.

result

The number in brackets after Salicylate is TBN.

As indicated above, the Larsen tech count minimum was achieved by the use of Example 1 of the present invention (exhibiting better performance at lower particle counts).

Claims (9)

(i) an overbased alkyl-substituted hydroxybenzoate calcium salt of an TBN having an alkyl group of 20 to 28 carbon atoms of less than 250, and
(ii) an overbased alkyl-substituted hydroxybenzoate calcium salt of TBN of less than 250, wherein the alkyl group has from 14 to 18 carbon atoms
, Wherein the weight% Ca ratio of (ii) to (i) is greater than 1,
≪ RTI ID = 0.0 > lubrication < / RTI >
Of the trunk piston marine engine. The method according to claim 1,
wherein the hydroxybenzoates of (i) and (ii) are salicylates, respectively. 3. The method according to claim 1 or 2,
wherein the alkyl group of (i) has from 20 to 24 carbon atoms. 4. The method according to any one of claims 1 to 3,
Wherein the composition has a TBN in the range of from 20 to 60, preferably from 25 to 55. < Desc / Clms Page number 13 > 5. The method according to any one of claims 1 to 4,
Wherein the weight% Ca ratio ranges from 1 to 50, preferably from 1 to 3. 6. The method according to any one of claims 1 to 5,
Wherein the composition comprises a major amount of a lubricating viscous oil containing at least 50% by weight of a basestock containing less than 90% saturation and / or greater than 0.03% sulfur. 6. The method according to any one of claims 1 to 5,
Wherein the composition comprises a major amount of lubricating viscous oil containing at least 50% by weight of a basestock containing at least 90% saturates and / or up to 0.03% sulfur. (I) an overbased alkyl-substituted < RTI ID = 0.0 > alkyl-substituted < / RTI > alkylene group of a TBN of less than 250 having an alkyl group of 20 to 28 carbon atoms, in a trunk piston vessel lubricant composition for a medium- (Ii) an overbased alkyl-substituted hydroxybenzoate calcium salt of TBN of less than 250, wherein the alkyl group has from 14 to 18 carbon atoms, wherein (i) the hydroxybenzoate calcium salt, (Ii), wherein the weight percent Ca ratio of (ii) is greater than 1. As a use of the detergent system,
To improve the asphaltene dispersibility of the composition. (I) an overbased alkyl (meth) acrylate having an alkyl group of from 20 to 28 carbon atoms, with a TBN of less than 250, in a trunk piston lubricating oil composition for a medium speed compression-ignition marine engine, Substituted hydroxybenzoate calcium salt, and (ii) an overbased alkyl-substituted hydroxybenzoate calcium salt of TBN of less than 250, wherein the alkyl group has from 14 to 18 carbon atoms, , wherein the weight% Ca ratio of (ii) to (i) is greater than 1,
Wherein the weight% Ca ratio is less than or equal to 1 and / or (ii) has a TBN greater than or equal to 250.