Classifications

• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L10/00—Use of additives to fuels or fires for particular purposes
  • C10L10/08—Use of additives to fuels or fires for particular purposes for improving lubricity; for reducing wear
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/14—Organic compounds
  • C10L1/18—Organic compounds containing oxygen
• • C—CHEMISTRY; METALLURGY
  • C10—PETROLEUM, GAS OR COKE INDUSTRIES; TECHNICAL GASES CONTAINING CARBON MONOXIDE; FUELS; LUBRICANTS; PEAT
  • C10L—FUELS NOT OTHERWISE PROVIDED FOR; NATURAL GAS; SYNTHETIC NATURAL GAS OBTAINED BY PROCESSES NOT COVERED BY SUBCLASSES C10G, C10K; LIQUEFIED PETROLEUM GAS; ADDING MATERIALS TO FUELS OR FIRES TO REDUCE SMOKE OR UNDESIRABLE DEPOSITS OR TO FACILITATE SOOT REMOVAL; FIRELIGHTERS
  • C10L1/00—Liquid carbonaceous fuels
  • C10L1/10—Liquid carbonaceous fuels containing additives
  • C10L1/14—Organic compounds
  • C10L1/18—Organic compounds containing oxygen
  • C10L1/19—Esters ester radical containing compounds; ester ethers; carbonic acid esters
  • C10L1/191—Esters ester radical containing compounds; ester ethers; carbonic acid esters of di- or polyhydroxyalcohols

Definitions

• the present invention relates to a fuel oil composition comprising a diesel fuel oil, and a fuel oil lubricity improver having improved cold storability.
• the invention further relates to the use of a composition having improved cold storability as a diesel fuel oil lubricity improver.
• ester additives are known for addition to hydrocarbon compositions for various purposes.
• US 2993773 describes esters of alkenyl succinic acid with a large variety of different alcohols. These esters are used to inhibit or prevent deposit-forming in hydrocarbon fuels.
• GB 1065398 describes how the lubricity of aviation turbojet fuels might be improved using partial esters of a number of different polyhydric alcohols, especially an ester of a C36 dimer acid and sorbitan monooleate.
• GB 1047493 is concerned with the addition of a lubricity additive to a lubricating oil in which the lubricity additive is a partial or mono ester of a dicarboxylic acid and an oil insoluble glycol such as the monoester of the C36 linoleic dimer acid and glycol.
• WO 98/11178 discloses a polyol ester distillate fuel additive which exhibits improved lubricity, wear and frictional performance.
• the polyol ester has unconverted hydroxyl groups.
• Pentaerythritol is mentioned as one of the alcohol that can be used.
• DE 196 14 722 A relates to additives for fuels and lubricants essentially consisting of a fatty acid mono-ester, or a mixture of mono- and di-esters of unsaturated fatty acids having 16-22 C atoms with at least two different polyols. These additives are said to exhibit better low temperature behaviour than corresponding monoesters or mono and diester of uniform polyols.
• EP 0 826 765 A relates to fuel additives for improving lubricity.
• the additives comprise at least one partial ester of at least one monocarboxylic acid and at least one polyol.
• the monocarboxylic acid comprises a C4-C24 linear or branched, saturated or unsaturated acid that may be hydroxylated.
• FR 2 772 783 relates to a lubricious additive for fuels having a low sulphur content (less than 500 ppm) .
• the additive comprises a mixture of a glycerol monoester (5-95 wt . % ) with another ester or an amine.
• WO 98/21293 relates to low sulphur diesel fuels containing additives which increase lubricity and reduce smoke in the exhaust.
• the additive comprises a mixture of two different esters.
• a preferred ester is one which has no free hydroxyl groups .
• WO 97/04044 relates to additives for improving the lubricity of fuel oils such as diesel fuel oil.
• This additive is a mixture of esters of unsaturated monocarboxylic acids.
• Preferred polyols for forming the esters are saturated aliphatic straight chain polyols .
• US 3 672 854 relates to a middle distillate having an improved pour point, containing a pour point depressant.
• the depressant comprises an ester of a saturated C14-C26 carboxylic acid and a polyhydric alcohol having from 4 to 8 hydroxyl groups.
• US 5 378 249 relates to a biodegradable two cycle engine oil composition
• a biodegradable two cycle engine oil composition comprising a heavy ester a light ester and additives.
• the oil is mixed with gasoline for the purpose of lubrication.
• Diesel fuel oils generally comprise petroleum middle distillate fuel oils which boil within the range of about 100°C to about 400°C. There has recently been a drive to reduce the sulphur content of such diesel fuels so as to reduce sulphur dioxide emissions for environmental reasons. As of October 1996, the EU imposed a maximum sulphur content for diesel fuel oil of 0.05% by weight. As a result of this, a problem has arisen in that preparation of low sulphur content fuel oils also reduces the content in the fuels of other components such as polyaromatics . The problem is that the lubricity of the fuel is reduced and this can lead to engine failure.
• WO 94/17160 In order to overcome this problem, it has been proposed in WO 94/17160 to provide diesel fuel oil compositions with a lubricity improver additive.
• Particular examples of such an additive disclosed in WO 94/17160 are glycerol monooleate esters and di-isodecyl adipate esters.
• Glycerol monooleate esters are in commercial use as diesel fuel oil additives to enhance the lubricity of the diesel fuel oils.
• EP-A-0773278 also addresses this problem, providing as a lubricity improver additive a hydroxy-substituted carboxylic acid or acid derivative such as ricinoleic acid or glycerol monoricinoleate .
• the present invention is concerned with a new problem which arises with diesel fuel oil lubricity improvers such as glycerol monooleate.
• diesel fuel oil lubricity improvers such as glycerol monooleate.
• manufacturers recommend that the product be stored above 10°C. This is necessary because, at lower temperatures, the known diesel fuel oil lubricity improvers become unstable with a tendency to cloud or even freeze.
• the requirement to store at above 10°C to prevent these drawbacks is inconvenient and costly for customers who have to provide specialised storage facilities.
• a further aim of the present invention is to provide a lubricity improver which also has improved cold storability.
• the present invention aims to overcome the drawbacks of the prior art .
• the present invention provides use of a composition comprising an ester of a monocarboxylic acid and a polyhydric alcohol as a diesel fuel oil lubricity improver, wherein the monocarboxylic acid comprises a C 8 -C 24 linear or branched chain unsaturated acid or a mixture thereof, and the polyhydric alcohol comprises an alcohol of the general formula:
• R 1 , R 2 and R 3 are each independently a C ⁇ -C ⁇ 2 linear or branched chain alkylol and R 4 is a linear or branched chain C ⁇ -C ⁇ 2 alkyl or a linear or branched chain C ⁇ C ⁇ 2 alkylol,
• ester comprises at least two free hydroxyl groups.
• the present invention provides a fuel oil composition
• a fuel oil composition comprising a diesel fuel oil having a sulphur content of no more than 0.05% by weight and a fuel oil lubricity improver comprising an ester of a monocarboxylic acid and a polyhydric alcohol, wherein the monocarboxylic acid comprises a C 8 -C 24 linear or branched chain unsaturated acid or a mixture thereof, and the polyhydric alcohol comprises an alcohol of the general formula:
• R 1 , R 2 and R 3 are each independently a C ⁇ -C ⁇ 2 linear or branched chain alkylol and R 4 is a linear or branched chain C ⁇ -C ⁇ 2 alkyl or a linear or branched chain C ⁇ C ⁇ 2 alkylol,
• ester comprises at least two free hydroxyl groups.
• esters of the present invention as a diesel fuel oil lubricity improver enables the product to be storable as a liquid at a temperature below 20°C, even at a temperature below -10°C.
• the esters of the present invention possess ability comparable to the products currently on the market to improve the lubricity of diesel fuel oils. Accordingly, the need to use specialist storage facilities for the lubricity improvers is obviated.
• the ester of the present invention preferably comprises a diester, which may be part of a mixture comprising a monoester and a diester, and optionally including higher esters such as a triester and a tetraester.
• R 1 , R 2 and R 3 are preferably each independently a C ⁇ C linear or branched chain alkylol, more preferably CH 2 OH.
• R 4 is preferably a C ⁇ -C linear or branched chain alkyl or alkylol, such as CH 3 , CH 2 0H or CH 2 CH 3 . More preferably R 4 is an alkylol so as to increase the number of free -OH groups in the ester.
• a particularly preferred alcohol component of the ester is pentaerythritol, although other alcohols such as trimethylolpropane (TMP) and trimethylolethane (TME) may be used.
• TMP trimethylolpropane
• TME trimethylolethane
• the final ester should have at least two free -OH groups.
• the lubricity improver used in the present invention may comprise a single pure ester, or may comprise a mixture containing two or more esters.
• the carboxylic acid component of the ester may be a linear or branched chain carboxylic acid which is unsaturated and is preferably a C ⁇ 2 -C 22 monocarboxylic acid.
• the carboxylic acid has an iodine value of 40 to 180, preferably an iodine value above 60, more preferably above 70, as measured in accordance with the AOCS (American Oil Chemists Society) Official Method cd-1-25. It is preferred to use an unsaturated carboxylic acid, since these are readily available and are often naturally- occurring.
• Particularly useful unsaturated carboxylic acids include oleic acid, linoleic acid, linolenic acid, palmoleic acid, gadoleic acid, erucic acid and other unsaturated acids with 22 carbon atoms and mixtures thereof.
• the unsaturated carboxylic acid component may be selected from tall oil fatty acids, soybean fatty acids, rape seed fatty acids, sunflower seed fatty acids, fish oil and fatty acids, and cold fractionated tallow and palm oil fatty acids.
• the monocarboxylic acid may be substituted, for example, by at least one hydroxyl group.
• a suitable substituted monocarboxylic acid is ricinoleic acid.
• the esters of the present invention such as the pentaerythritol esters, have a cold stability which is independent of the molar ratio of fatty acid to alcohol.
• lubricity efficiency increases with a decrease in ratio of fatty acid to alcohol in both pentaerythritol and monoglycerides; in the monoglycerides the cold stability decreases whereas in the pentaerythritol esters it does not.
• the amount of fuel oil lubricity improver used in the fuel oil is in the range 1 to lOOOppm, preferably in the range 10 to 500ppm, most preferably in the range 10 to 200ppm.
• the ester of the present invention may be used as the diesel fuel oil lubricity improver in pure form or in mixture with other components such as the conventional diesel fuel oil lubricity improvers, such as glycerol monooleate.
• the amount of ester of the present invention in such a mixture is in the range 60 to 100%wt, preferably in the range 80 to 100%wt, most preferably in the range 90 to 95%wt, especially around 92%.
• the properties of these mixtures are also improved over known lubricity improvers.
• the fuel oil incorporated an amount of lubricity improver as set out in Table 1 below so as to compare the effectiveness of lubricity improvers according to the present invention with those of the prior art.
• a High Frequency Reciprocating Rig (HFRR) test was carried out as described in D. Wei and H. Spikes, Wear, Vol. Ill, No. 2, p. 217, 1986; and R. Caprotti, C. Bovington, W. Fowler and M. Taylor SAE paper 922183; SAE fuels and lubes. Meeting Oct. 1992; San Francisco, USA.
• the present applicants are aiming for a wear scar diameter of less than 400 microns at a dosage level of lOOppm.
• Lubricity improver A is a mixture of pentaerytritolmonooleate, pentaerytritoldioleate and pentaerytritoltrioleate including 39% diester.
• the olefin fraction used for the synthesis of this pentaerythritol ester and for the glycerolmonooleate was obtained by a cold fractionation of tallow fatty acids and has cloud point between 0°C and 6°C.
• Lubricity improver B is a mixture of 92% of A and 8% of the glycerolmonooleate.
• Additive A from WO 97/04044 was prepared by esterification of a commercial mixture of oleic and linoleic acids with glycerol to produce a mixed ester product comprising glycerol monooleate and glycerol monolinoleate in approximately equal proportions by weight, and containing minor amounts of glycerol di- and trioleate and linoleate.
• Table 2 cloud poin t and pour point of glycerolmonoolea te and l ubri ci ty improvers A and B
• the pour points of the different compounds mentioned in example 3 are compared.
• the pour points of two additives described in WO 97/38965 are also compared.
• These additives are mixtures of trimethylolpropane monotalloate (TMP) (ester B of WO 97/38965) and glycerol monotalloate (ester A of WO 97/38965) .
• TMP trimethylolpropane monotalloate
• glycerol monotalloate ester A of WO 97/38965
• talloate means formed with tall oil fatty acids. The results are shown in Table 4.
• esters of the present invention have good lubricity improvement properties for diesel fuel oils and superior cold storage properties as compared with the lubricity improvers of the prior art.

Landscapes

• Chemical & Material Sciences (AREA)
• Oil, Petroleum & Natural Gas (AREA)
• Engineering & Computer Science (AREA)
• Organic Chemistry (AREA)
• Health & Medical Sciences (AREA)
• Emergency Medicine (AREA)
• Chemical Kinetics & Catalysis (AREA)
• General Chemical & Material Sciences (AREA)
• Combustion & Propulsion (AREA)
• Liquid Carbonaceous Fuels (AREA)
• Solid Fuels And Fuel-Associated Substances (AREA)

Priority Applications (6)

Applications Claiming Priority (2)

Publications (1)

Family

ID=8238962

Family Applications (1)

Country Status (7)

Cited By (6)

Families Citing this family (3)

Citations (10)

• 1999
  • 1999-09-10 EP EP99117853A patent/EP1088880A1/de not_active Withdrawn
• 2000
  • 2000-09-07 KR KR1020027003126A patent/KR20020051918A/ko not_active Application Discontinuation
  • 2000-09-07 DE DE60002224T patent/DE60002224T2/de not_active Expired - Fee Related
  • 2000-09-07 JP JP2001523713A patent/JP2003509569A/ja active Pending
  • 2000-09-07 EP EP00960644A patent/EP1216288B1/de not_active Expired - Lifetime
  • 2000-09-07 AT AT00960644T patent/ATE237665T1/de not_active IP Right Cessation
  • 2000-09-07 WO PCT/EP2000/008869 patent/WO2001019941A1/en active Search and Examination
  • 2000-09-07 AU AU72864/00A patent/AU7286400A/en not_active Abandoned

Patent Citations (10)

Also Published As

Similar Documents

Legal Events