DESC:FIELD
The present disclosure relates to a lubricity additive composition and a process for its preparation.
DEFINITIONS
As used in the present disclosure, the following terms are generally intended to have the meaning as set forth below, except to the extent that the context in which they are used indicates otherwise.
Ultra-low sulfur diesel (ULSD) –refers to a cleaner diesel fuel containing a maximum of 10 ppm sulfur.
Lubricity of a fuel- refers to an ability of a fuel to prevent or minimize wear and tear due to friction between mobile parts of an engine.
Lubricity improver – refers to an additive added to the fuel for reducing friction between mobile parts of an engine to prevent or minimize wear and tear.
BACKGROUND
The background information herein below relates to the present disclosure but is not necessarily prior art.
The most common transportation fuels used are gasoline and diesel. When a transportation fuel is combusted in an engine, several pollutants are emitted. One of the major pollutants emitted is sulfur dioxide, produced as a consequence of oxidation of sulfur present in the fuel. In order to reduce the emission of sulfur dioxide, removal of sulfur from the fuel is necessary. Refineries have, therefore, adopted processes to reduce sulfur levels in the fuels.
Conventional fuel is a mixture of aliphatic hydrocarbons, wherein some polar molecules containing oxygen and nitrogen are also present. These polar molecules contribute to the inherent lubricity of a fuel. The process of de-sulfurization adopted by various refineries for reducing sulfur levels concurrently reduces other polar molecules as well. Thus, the removal of polar molecules from fuel during the de-sulfurization process also reduces the inherent lubricity of the fuel. The degree of loss of inherent lubricity of a fuel is proportional to the degree of desulfurization of fuel.
There is a continued worldwide movement for reducing the sulfur content in diesel. Sulfur is reduced to a very low level of 10 ppm in the case of ultra-low sulfur diesel (ULSD) through a process of extreme desulfurization. The reduction of sulfur through the process of extreme de-sulfurization also results in the removal of other polar molecules significantly, reducing inherent fuel lubricity very significantly. ULSD cannot be used as such in view of the loss of its inherent lubricity and therefore, a lubricity improver needs to be added to such fuels.
Conventionally, a fatty acid ester, amide, or a salt derivative, are known to be lubricity improvers. A fatty acid ester is prepared by using a dimer acid, which is a fatty acid, and an alcohol amine. Secondly, a reaction product of a fatty amine and a fatty acid is also a lubricity improver. However, the fatty acid raw material is costly and therefore, lubricity improvers prepared from them are costly.
Fatty acid esters of rapeseed oil, sunflower oil, and castor oil are also known to be lubricity improvers. Although the raw materials for these fatty acid esters are cheap and readily available, they get deposited at low temperatures and therefore, are not effective lubricity improvers at higher temperatures.
Thus, there is a need to provide an effective and economical lubricity additive composition and a process for the preparation that mitigates the drawbacks mentioned hereinabove.
OBJECTS
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
It is an object of the present disclosure is to ameliorate one or more problems of the prior art or to at least provide a useful alternative.
An object of the present disclosure is to provide a lubricity additive composition for improving the lubricity of fuels.
Another object of the present disclosure is to provide a simple and economical process for preparing a lubricity additive composition.
Still another object of the present disclosure is to prepare a lubricity additive composition from a hydrocarbon fraction in a refinery.
Other objects and advantages of the present disclosure will be more apparent from the following description, which is not intended to limit the scope of the present disclosure.
SUMMARY
The present disclosure relates to a lubricity additive composition and a process for its preparation.
In an aspect, the lubricity additive composition comprises an esterified product of at least one olefin. The olefin is selected fromC4 to C10 olefin. The composition when mixed with ULSD (ultra-low sulphur diesel) exhibits enhanced wear scar diameter (WSD).
In another aspect, the process for the preparation of a lubricity additive composition comprises oxidizing at least one olefin by using at least one oxidizing agent under stirring at first predetermined temperature for a first predetermined time period to obtain an epoxidized product of olefin. The epoxidized product of the olefin is reacted with a fatty acid in the presence of an acid catalyst at a second predetermined temperature for a second predetermined time period to obtain a product mixture comprising the esterified product of the olefin and an unreacted fatty acid. The so obtained esterified product of the olefin is separated from the product mixture to obtain the esterified product of olefin.
DETAILED DESCRIPTION
Embodiments are provided so as to thoroughly and fully convey the scope of the present disclosure to the person skilled in the art. Numerous details are set forth, relating to specific components, and methods, to provide a complete understanding of embodiments of the present disclosure. It will be apparent to the person skilled in the art that the details provided in the embodiments should not be construed to limit the scope of the present disclosure. In some embodiments, well-known processes, well-known apparatus structures, and well-known techniques are not described in detail.
The terminology used, in the present disclosure, is only for the purpose of explaining a particular embodiment and such terminology shall not be considered to limit the scope of the present disclosure. As used in the present disclosure, the forms "a,” "an," and "the" may be intended to include the plural forms as well, unless the context clearly suggests otherwise. The terms "comprises," "comprising," “including,” and “having,” are open ended transitional phrases and therefore specify the presence of stated features, integers, steps, operations, elements, modules, units and/or components, but do not forbid the presence or addition of one or more other features, integers, steps, operations, elements, components, and/or groups thereof. The particular order of steps disclosed in the method and process of the present disclosure is not to be construed as necessarily requiring their performance as described or illustrated. It is also to be understood that additional or alternative steps may be employed.
Transportation fuels emit pollutants on combustion. One of the major pollutants emitted is sulfur dioxide, the amount of which is dependent on the amount of sulfur present in the combusted fuel. Restrictions have been placed worldwide on the permissible limit of sulfur in fuel and therefore, refineries remove sulfur from fuel through the process of de-sulfurization. The process of removal of sulfur also results in the removal of other polar molecules containing oxygen and nitrogen. The presence of polar molecules in the fuel contributes to its inherent lubricity and therefore, their removal during the process of de-sulfurization leads to loss of inherent lubricity of the fuel. The degree of loss of inherent lubricity of the fuel is proportional to the degree of desulfurization of the fuel.
In the case of ULSD (ultra-low sulphur diesel), as sulfur is reduced to a very low level of 10 ppm, its inherent lubricity is considerably reduced, for the reason explained hereinabove. In order to improve the lubricity of fuel, a lubricity improver is required to be added to the fuel.
Fatty acid ester, amide, or salt derivatives are known to be lubricity improvers. A dimer acid, which is a fatty acid reacts with an alcohol amine react to produce a fatty acid ester. Secondly, the reaction product of a fatty amine and a fatty acid can also be used as a lubricity improver. The costs of fatty acid as raw material are high and therefore, lubricity improvers prepared from them are costly.
Fatty acid esters of rapeseed oil, sunflower oil, and castor oil are also known to be lubricity improvers. Although the raw materials for these fatty acid esters are cheap and readily available, they get deposited at low temperatures and therefore, are not effective lubricity improvers at higher temperatures.
The present disclosure solves the problem by providing an economical and effective lubricity additive composition.
In an aspect of the present disclosure, there is provided a lubricity additive composition.
The lubricity additive composition comprises an esterified product of at least one olefin.
In an embodiment, the olefin is selected from C4 to C10 olefin.
In an embodiment, the olefin is at least one selected from hexene and light cracked naphtha (LCN). In an exemplary embodiment of the present disclosure, the olefin is hexene. In another exemplary embodiment of the present disclosure, the olefin is light cracked naphtha (LCN).
In an embodiment, the composition comprises the esterified product of a mixture of olefins.
In another aspect of the present disclosure, there is provided a process for the preparation of an esterified product that can be used as a lubricity additive for improving lubricity. Particularly, the present disclosure provides a process for the preparation of esterified product obtained by epoxidation of olefin followed by esterification with fatty acid.
The process is described in detail.
In the first step, at least one olefin is oxidized by using at least one oxidizing agent under stirring at a first predetermined temperature for a first predetermined time period to obtain an epoxidized product of the olefin.
In an embodiment, the olefin is at least one selected from hexene and light cracked naphtha (LCN). In an exemplary embodiment of the present disclosure, the olefin is hexene. In another exemplary embodiment of the present disclosure, the olefin is light cracked naphtha (LCN).
In an embodiment, the light cracked naphtha (LCN) is obtained from the petrochemical fluidized catalytic cracking (PFCC) unit. The component analysis of the LCN is evaluated using the Reformulizer-M4 of PAC by using ASTM D 6839 method. The composition of the LCN is provided below in Table 1.
Table 1: Component analysis of LCN
Normalized volume percent result (LCN)
Carbon number Naphthenes Paraffins Cyclo- olefins Olefins Aromatics Total
4 - 0.39 - 0.18 - 0.57
5 0.73 18.08 0.88 28.61 - 48.30
6 2.39 9.93 2.03 6.33 3.74 24.41
7 2.55 3.33 1.50 1.31 7.70 16.38
8 1.27 1.39 0.37 0.27 4.49 7.80
9 0.25 0.21 0.13 0.31 0.61 1.52
10 0.05 - - - 0.79 0.83
11 0.15 - - 0.04 - 0.19
12+ - - - - - -
Poly - - - - - -
Total 7.38 33.32 4.92 37.05 17.33 100
The LCN contains 41.97% of olefins and is converted into respective epoxides upon epoxidation reaction.
In an embodiment, the oxidizing agent is at least one selected from performic acid, peracetic acid, and meta-chloroperoxybenzoic acid (m-CPBA). In an exemplary embodiment of the present disclosure, the oxidizing agent is peracetic acid. In another exemplary embodiment of the present disclosure, the oxidizing agent is meta-chloroperoxybenzoic acid (m-CPBA).
In an embodiment, the first predetermined time period is in the range of 7 hours to 10 hours. In an exemplary embodiment of the present disclosure, the first predetermined time period is 8 hours.
In an embodiment, the first predetermined temperature is in the range of 20 °C to 50 °C. In an exemplary embodiment of the present disclosure, the first predetermined temperature is 25oC.
In a second step, a fatty acid is added to the epoxidized product of the olefin followed by reacting in the presence of an acid catalyst at a second predetermined temperature for a second predetermined time period to obtain a product mixture comprising an esterified product of the olefin and an unreacted fatty acid.
In an embodiment, the fatty acid is at least one selected from stearic acid, capric acid, butyric acid, palmitic acid, myristic acid, lauric acid, 2-ethyl hexanoic acid, octanoic acid, hexanoic acid, and pentanoic acid. In an exemplary embodiment of the present disclosure, the fatty acid is stearic acid. In another exemplary embodiment of the present disclosure, the fatty acid is capric acid. In yet another exemplary embodiment, the fatty acid is butyric acid.
In an embodiment, the acid catalyst is p-toulenesulphonic acid (PTSA).
In an embodiment, the second predetermined temperature is in the range of 50 °C to 120 °C. In an exemplary embodiment of the present disclosure, the predetermined temperature is 60 °C. In another exemplary embodiment of the present disclosure, the predetermined temperature is 100 °C.
In an embodiment, the second predetermined time period is in the range of 8 to 12 hours. In an exemplary embodiment of the present disclosure, the second predetermined time period is 10 hours.
In an embodiment, a ratio of the epoxidized product of the olefin to the fatty acid is in the range of 1:1.
In a final step, the so obtained esterified product of the olefin is separated from the product mixture to obtain the lubricity additive composition.
In an embodiment, the product mixture is mixed with at least one organic fluid medium to obtain a first mixture. The first mixture is allowed to settle and the organic layer is separated to obtain first separated organic layer. The first separated layer is washed with water followed by a weak base to remove unreacted fatty acid, and separating the washed organic layer to obtain a second separated organic layer. The moisture in second organic layer is removed using anhydrous sodium sulphate to obtain moisture free organic layer. The organic fluid medium in moisture free organic layer is removed under vacuum to obtain the additive composition.
In an embodiment, the organic fluid medium is ethyl acetate.
In an embodiment, the weak base is sodium bicarbonate.
In an embodiment, the lubricity additive composition when added to ULSD exhibits an average wear scar diameter (WSD) in the range of 400 µm to 450 µm in accordance with ASTM D 6079-18.
The present disclosure provides the economical process for the preparation of lubricity additive composition comprising the esterified product of the olefin, which upon mixing with ULSD improves the antiwear properties.
In an embodiment of the present disclosure, the additive composition comprising the esterified product of at least one olefin is added to ULSD at a concentration in the range of 150 ppm to 400 ppm. The performance of ULSD mixed with a lubricity additive composition comprising esterified product is evaluated by using High Frequency Reciprocating Rig (HFRR) based on ASTM D 6079-18.
The foregoing description of the embodiments has been provided for purposes of illustration and is not intended to limit the scope of the present disclosure. Individual components of a particular embodiment are generally not limited to that particular embodiment, but, are interchangeable. Such variations are not to be regarded as a departure from the present disclosure, and all such modifications are considered to be within the scope of the present disclosure.
The present disclosure is further described in light of the following experiments which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure. The following experiments can be scaled up to industrial/commercial scale and the results obtained can be extrapolated to industrial scale.
EXPERIMENTAL DETAILS
Experiment I: Preparation of esterified product from 1-hexene (as olefin) in accordance with the present disclosure

Hexene was oxidized by performic acid or peracetic acid or m-CPBA to obtain epoxyhexane, followed by esterification with fatty acid to obtain an esterified product of hexene. A schematic representation of the process for the preparation of esterified product from hexene was given as scheme I

Scheme I

Example 1: Preparation of epoxyhexane by using peracetic acid as oxidizing agent (epoxidation)

160 gm of 1-hexene was cooled in an ice bath for 15 min followed by the addition of peracetic acid (400 gm of H2O2 and 400 gm of glacial acetic acid) slowly dropwise for 45 minutes to obtain a reaction mixture. The reaction mixture was stirred for 8 hours at 25 °C to obtain a product mixture containing epoxidized hexene. The reaction was monitored by using gas chromatography. After completion of the reaction, 500 mL of distilled water was added to the product mixture containing epoxidized product. The epoxidized product was extracted using 200 ml dichloromethane (DCM). The dichloromethane layer (organic layer) was separated and washed with excess water, and 200ml 1.0 M sodium bicarbonate. Further, the separated DCM layer was dried over anhydrous sodium sulphate, followed by removing DCM under vacuum to obtain 1,2-epoxyhexane. The yield of the product was85-88%.
Example 2: Preparation of epoxyhexane by using m-CPBA as oxidizing agent (epoxidation)
6 g of 1-hexene was mixed with 10 mL of dichloromethane (DCM) under stirring for 5 min, by maintaining the temperature in the range of 0-5 °C to obtain a mixture. Separately, 7g of meta-chloroperoxybenzoic acid (m-CPBA) was dissolved in 20 ml of DCM to obtain a solution and the solution was added dropwise to the mixture to obtain a resultant mixture. The resultant mixture was stirred for 8 hours at 30oC to obtain a reaction mixture. The reaction was monitored by using gas chromatography. After completion of the reaction, the reaction mixture was washed with 10 mL of 2% sodium sulphite followed by 10 mL of sodium carbonate solution to obtain a product mixture. Further, the product mixture was extracted with 50 mL DCM. The DCM layer was separated and washed with an excess of water. The so obtained DCM layer was dried over sodium sulphate and DCM was removed under pressure to obtain 1,2-epoxyhexane. The yield of the product was 92-94%.
Example 3: Preparation of ester in accordance with the present disclosure
5g of 1,2-epoxyhexane was reacted with 14.5g of stearic acid to obtain a mixture. To the mixture, 0.2g of p-toluenesulphonic acid (PTSA) was added and heated to 60 oC and maintained the reaction at 60 °C for 10 hours under nitrogen atmosphere to obtain a reaction mixture. The reaction was monitored by using thin layer chromatography. After completion of the reaction, the reaction mixture was mixed with 50 mL ethyl acetate to obtain the resultant mixture. The so obtained resultant mixture was allowed to settle and the ethyl acetate layer was separated to obtain a first separated ethyl acetate layer. The first separated ethyl acetate layer was washed with excess water followed by 1M sodium carbonate solution to remove unreacted stearic acid and separating the washed ethyl acetate layer to obtain a second separated ethyl acetate layer. The moisture in the second separated ethyl acetate layer was removed using anhydrous sodium sulphate to obtain a moisture free ethyl acetate layer. The ethyl acetate is removed from moisture free ethyl acetate layer under vacuum to obtain the lubricity additive composition (3a) as a dark yellow liquid. The yield of the product was 82%.

Example 4: Preparation of ester (Esterification) in accordance with the present disclosure
The esters were prepared using 1,2-epoxyhexane similar to the process disclosed in Example 3 by varying the fatty acids, the resultant compounds are provided below in Table 2.
Table 2: Esters produced by corresponding fatty acid
Acid Obtained product
Stearic acid
C18H36O2
3a
Capric acid
C10H20O2
3b
Butyric acid
C4H8O2
3c
Experiment II: Preparation of esterified product from light cracked naphtha (LCN) in accordance with the present disclosure
Light cracked naphtha (LCN) was oxidized by using performic acid or peracetic acid or m-CPBA as an oxidizing agent to obtain epoxidized naphtha, followed by esterification with fatty acids to produce an esterified product.
A schematic representation of the process for the preparation of esterified product from hexene was given as scheme II

Scheme II
Example 5: Preparation of epoxydized naphtha by using peracetic acid as oxidizing agent (epoxidation)
160 gm of light cracked naphtha (LCN)was cooled in an ice bath to a temperature of 5 °C, followed by the addition of peracetic acid (400 gm of H2O2 and 400 gm of glacial acetic acid) slowly dropwise for 45 minutes in a cooled light cracked naphtha to obtain a reaction mixture. The reaction mixture was stirred for 8 hours maintaining the temperature of25 °C to obtain a product mixture containing epoxidized product. The reaction was monitored by using gas chromatography. After completion of the reaction, 500 mL of distilled water was added to the product mixture containing epoxidized product. The epoxidized product was extracted by using 100 mL dichloromethane (DCM). The DCM layer was separated and the so obtained DCM layer was washed with an excess of water followed by 1.0 M sodium bicarbonate and dried over anhydrous sodium sulphate. The remaining DCM was removed under vacuum to obtain a mixture of epoxides (5). The yield of the product was 85.8 %.
The conversion of olefins to the mixture of epoxides depends on the reaction time. The conversion percentage of olefin was evaluated at various time intervals, the details are summarized in Table-3 below

Table – 3: Conversion percentage of olefin
Sample Olefin, vol%
ASTM D 6839 Conversion (%)
Pure LCN 41.97 -
Reaction mixture after 2 hrs 20.19 51.9
Reaction mixture after 4 hrs 9.56 77.2
Reaction mixture after 6 hrs 6.55 84.4
Reaction mixture after 8 hrs 5.98 85.8

Example 6: Preparation of epoxidized naphtha by using m-CPBA as oxidizing agent (epoxidation)
200 g of light cracked naphtha (LCN) was mixed with 50 mL of dichloromethane (DCM) to obtain a mixture. Separately, 70 g of meta-chloroperoxybenzoic acid (m-CPBA) was dissolved in DCM to obtain a solution and the solution was added drop-wise to the mixture, maintaining the temperature in the range of 0-5°C to obtain a resultant mixture. The resultant mixture was stirred for 8 hours at 30 oC to obtain a reaction mixture. After completion of the reaction, the reaction mixture was washed with 100 mL of 2% sodium sulphite followed by 100 mL of 2% sodium carbonate solution to obtain a product mixture. The so obtained product mixture was extracted with 200 mL of DCM. The DCM layer was dried using anhydrous sodium sulphate and the DCM was removed under pressure to obtain a mixture of epoxides (5).
The conversion of olefins to the mixture of epoxides depends on the reaction time. The conversion percentage of olefin was evaluated at various time intervals, the details are summarized in Table-4 below

Table – 4: Conversion percentage of olefin
Sample Olefin, vol%
ASTM D 6839 Conversion (%)
Pure LCN 41.97 -
Reaction mixture after 2 hrs 19.45 53.6
Reaction mixture after 4 hrs 8.42 79.9
Reaction mixture after 6 hrs 4.51 89.3
Reaction mixture after 8 hrs 3.98 90.5

Example 7: Preparation of ester (Esterification)
The mixture of epoxides obtained in Examples 5 and 6 was esterified by using a similar process disclosed in Example 3 by varying the fatty acids, the resultant esterified compounds are provided below in Table 5.
Table 5: Esterified product produced by corresponding fatty acid
Acid Obtained Product
Stearic acid
C18H36O2
6a
Palmitic acid
C16H32O2
6b
Myristic acid
C14H28O2
6c
Lauric acid
C12H24O2
6d
Capric acid
C10H20O2
6e
2-Ethyl hexanoic acid
C8H16O2
6f
Octanoic acid
C8H16O2
6g
Hexanoic acid
C6H12O2
6h
Pentanoic acid
C5H10O2
6i
Butyric acid
C4H8O2
6j
Wherein R, R1= H, C1, and C2 alkyl or aryl groups
Example 8:

The so obtained esterified products were mixed with diesel-ULSD (having 6 ppm (wt/vol) sulfur) in a concentration of 150 ppm and 300 ppm. The lubricity of the diesel was evaluated using the High Frequency Reciprocating Rig (HFRR) by using ASTM D 6079-18 method (A vibrator with 50Hz frequency, 1mm stroke length, 200g weight load, 2 mL sample, 60° C temperature, and duration of the test was 75 mins). The wear scar diameter (WSD) was calculated by measuring the length (as µm) of the scar in the X and Y direction of the wear scar formed on the ball’s surface, the WSD was calculated by using the equation WSD = (X+Y)/2 µm.
The results are illustrated below in Table 6.

Table 6: WSD of esterified products
HFRR 60oC, ASTM D 6079-18
Sample ID Concn.
ppm Wear scar (µm) Concn.
ppm Wear scar (µm)
Ball X Ball Y WSD,
(X+Y)/2 Ball X Ball Y WSD,
(X+Y)/2
Neat, ULSD NA 535 485 510 NA NA NA NA
3a 150 445 408 427 300 420 385 403
3b 150 472 448 460 300 448 415 432
3c 150 504 458 481 300 482 451 467
6a 150 425 396 410 300 405 359 382
6b 150 436 408 422 300 420 375 398
6c 150 440 412 426 300 428 384 406
6d 150 462 434 448 300 450 402 426
6e 150 466 438 452 300 442 410 426
6f 150 466 438 452 300 449 421 435
6g 150 485 452 469 300 472 438 455
6h 150 508 468 488 300 496 452 474
6i 150 515 485 500 300 518 490 504
6j 150 518 485 502 300 510 476 493

The maximum allowed limit for the lubricity value of BS VI ULSD is 460 µm. The ULSD blended with the esterified product of the present disclosure having a WSD value of less than or equal to 450 µm at 60° C is preferred. The size of the wear scar is directly related to the lubrication property of the sample.
It is evident from the above data, that esterified compounds 3a, 3b, 6a, 6b, 6c, 6d, 6e, and 6f are suitable as a lubricity additive for ULSD.
TECHNICAL ADVANCEMENTS
The present disclosure described herein above has several technical advantages including, but not limited to, the realization and a process for the preparation of a lubricity improver for a fuel which
- involves a simple and economical process;
- allows preparing a lubricity improver from a hydrocarbon fraction of a refinery;
- produces an effective lubricity additive composition.
Throughout this specification the word “comprise”, or variations such as “comprises” or “comprising, will be understood to imply the inclusion of a stated element, integer or step,” or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.
The use of the expression “at least” or “at least one” suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the invention to achieve one or more of the desired objects or results. While certain embodiments of the inventions have been described, these embodiments have been presented by way of example only, and are not intended to limit the scope of the inventions. Variations or modifications to the formulation of this invention, within the scope of the invention, may occur to those skilled in the art upon reviewing the disclosure herein. Such variations or modifications are well within the spirit of this invention.
The numerical values given for various physical parameters, dimensions, and quantities are only approximate values and it is envisaged that the values higher than the numerical value assigned to the physical parameters, dimensions, and quantities fall within the scope of the invention unless there is a statement in the specification to the contrary.
While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the disclosure. These and other changes in the preferred embodiment of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.
,CLAIMS:WE CLAIM:
1. A lubricity additive composition comprising an esterified product of at least one olefin.
2. The composition as claimed in claim 1, wherein said olefin is selected from C4 to C10 olefin.
3. The composition as claimed in claim 1, wherein said olefin is at least one selected from the group consisting of hexene, and light cracked naphtha (LCN).
4. The composition as claimed in claim 1, wherein said composition comprising the esterified product of mixture of olefins.
5. A process for preparing a lubricity additive composition comprising an esterified product, said process comprising the following steps:
a) oxidizing at least one olefin by using at least one oxidizing agent under stirring at a first predetermined temperature for a first predetermined time period to obtain an epoxidized product of said olefin;
b) adding a fatty acid to the epoxidized product of said olefin followed by reacting in the presence of an acid catalyst at a second predetermined temperature for a second predetermined time period to obtain a product mixture comprising an esterified product of said olefin and an unreacted said fatty acid; and
c) separating the esterified product of said olefin from the product mixture to obtain the lubricity additive composition.
6. The process as claimed in claim 5, wherein said olefin is at least one selected from the group consisting of hexene, and light cracked naphtha (LCN).
7. The process as claimed in claim 5, wherein said oxidizing agent is at least one selected from the group consisting of performic acid, peracetic acid, and meta-chloroperoxybenzoic acid (m-CPBA).
8. The process as claimed in claim 5, wherein said first predetermined time period is in the range of 7 hours to 10 hours.
9. The process as claimed in claim 5, wherein said first predetermined temperature is in the range of 20 °C to 50 °C.
10. The process as claimed in claim 5, wherein said fatty acid is selected from the group consisting of stearic acid, capric acid, butyric acid, palmitic acid, myristic acid, lauric acid, 2-ethyl hexanoic acid, octanoic acid, hexanoic acid, and pentanoic acid.
11. The process as claimed in claim 5, wherein said acid catalyst is p-toulenesulphonic acid (PTSA).
12. The process as claimed in claim 5, wherein said second predetermined temperature is in the range of 50 °C to 120 °C.
13. The process as claimed in claim 5, wherein said second predetermined time period is in the range of 8 hours to 12 hours.
14. The process as claimed in claim 5, wherein a ratio of said epoxidized product of olefin to fatty acid is 1:1.
15. The process as claimed in claim 5, wherein separation in step c) comprises the following sub-steps:
a) mixing said product mixture with at least one organic fluid medium to obtain a first mixture;
b) allowing said first mixture to settle and separating an organic layer to obtain a first separated organic layer;
c) washing said first separated organic layer with water followed by a weak base to remove unreacted fatty acid and separating the washed organic layer to obtain a second separated organic layer;
d) removing the moisture from said second separated organic layer by using anhydrous sodium sulphate to obtain a moisture free organic layer; and
e) removing the organic fluid medium from said moisture free organic layer under vacuum to obtain the additive composition.
16. The process as claimed in claim 15, wherein said organic fluid medium is ethyl acetate.
17. The process as claimed in claim 15, wherein said weak base is sodium bicarbonate.
18. The lubricity additive composition as claimed in any of the preceding claims, when added to ULSD (ultra-low sulphur diesel) exhibits an average wear scar diameter in the range of 400 µm to 450 µm in accordance with ASTM D 6079-18.