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 so as 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 various aliphatic hydrocarbons, wherein some polar molecules containing nitrogen and oxygen 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 the 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. The fatty acid ester is prepared by using a dimer acid, which is a fatty acid, and an alcohol amine. Secondly, the 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 its 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 a diester product of at least one olefin. The olefin is selected from C4 to C10 olefins. 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 maleating at least one olefin with maleic anhydride in an inert atmosphere at a first predetermined temperature for a first predetermined time period under stirring to obtain a reaction mixture comprising a maleated product of said olefin. Further, the maleated product of the olefin is reacted with at least one alcohol in the presence of an acid catalyst, at a second predetermined temperature for a second predetermined time period to obtain a product mixture comprising a diester product of the olefin and unreacted alcohol. The so obtained diester product of the olefin is separated from the product mixture to obtain the diester 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 herein above. In order to improve the lubricity of fuel, a lubricity additive composition 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, 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 a diester 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 diester product of a mixture of olefins.
In another aspect of the present disclosure, there is provided a process for the preparation of a diester product that can be used as a lubricity additive for improving lubricity. Particularly, the present disclosure provides a process for the preparation of diester products obtained by maleation of olefin followed by esterification with alcohol.
The process is described in detail.
In the first step, maleating at least one olefin with maleic anhydride in an inert atmosphere at a first predetermined temperature for a first predetermined time period under stirring to obtain a reaction mixture comprising a maleated 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 alkenyl succinic anhydrides upon maleation reaction with maleic anhydride.
In an embodiment, the inert atmosphere is selected from nitrogen or argon.
In an embodiment, the first predetermined temperature is in the range of 150 °C to 250°C. In an exemplary embodiment of the present disclosure, the first predetermined temperature is 200°C.
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 stirring in the first step is carried at a speed in the range of 500 rpm to 700 rpm. In an exemplary embodiment of the present disclosure, the mixture is stirred at a speed of 600 rpm.
In an embodiment, after completion of the reaction, the reaction mixture is cooled and kept overnight to allow unreacted maleic anhydride to settle in the bottom. The reaction mixture is filtered and concentrated using a rotary evaporator to remove the unreacted olefin.
In a second step, at least one alcohol is added to the maleated product of the olefin followed by reacting in the presence of an acid catalyst at a second predetermined temperature for a second time period to obtain a product mixture comprising a diester product of the olefin and unreacted alcohol.
In an embodiment, the alcohol is at least one selected from ethanol, n-octanol, n-hexadecanol, 1-butanol, 1-hexanol, 2-ethyl hexanol, 1-octanol, 1-decanol, 1-tetradecanol, and 1-hexadecanol.
In an embodiment, the acid catalyst is p-toulenesulphonic acid (PTSA).
In an embodiment, the second predetermined temperature is in the range of 90 °C to 130 °C. In an exemplary embodiment of the present disclosure, the second predetermined temperature is 110 °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 9 hours.
In an embodiment, a ratio of the maleated product of olefin to the alcohol is 1:2
In a final step, the so obtained diester 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 the first separated organic layer. The first separated layer is washed with water to obtain a washed organic layer. The moisture in washed 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 lubricity additive composition.
In an embodiment, the organic fluid medium is ethyl acetate.
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 diester 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 diester product of 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 diester 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 diester product from 1-hexene (as olefin) in accordance with the present disclosure
Hexene was maleated by maleic anhydride to obtain 2-hexen-1-ylsuccinic anhydride, followed by esterification with alcohol to obtain a diester product of hexene. A schematic representation of the process for the preparation of diester product from hexene was given as scheme I

Scheme I
Example 1: Maleation of 1-hexene
200 g of 1-hexene and233 g of maleic anhydride were charged into the high-pressure reactor and purged with nitrogen gas for 10 minutes followed by slowly raising the temperature to 200 °C to obtain a reaction mixture. The reaction mixture was cooled and kept overnight to allow unreacted maleic anhydride to settle in the bottom. The reaction mixture was filtered and concentrated by a rotary evaporator to remove the un-reacted 1-hexene to obtain 2-Hexen-1-ylsuccinic anhydride as a pale yellow liquid (325 gm). The yield of the product was 75%.
Example 2: Esterification of 2-Hexen-1-ylsuccinic anhydride with n-octanol
5 g of 2-Hexen-1-ylsuccinic anhydride was mixed with 7.1 g of n-octanol followed by 0.5 g of p-toluenesulphonic acid (PTSA) and 40 mL of toluene to obtain a reaction mixture. The reaction mixture was refluxed at 110 °C for 9 hours with constant stirring. The water liberated during the reaction was removed at regular intervals. The reaction was monitored by using thin-layer chromatography. After completion of the reaction, the reaction mixture was cooled at room temperature. The reaction mixture was mixed with 100 ml ethyl acetate to obtain the resultant mixture. The so obtained resultant mixture was allowed to settle and the ethyl acetate layer is separated to obtain a first separated ethyl acetate layer. The first separated ethyl acetate layer was washed with excess water and separating to obtain the washed ethyl acetate layer. The moisture in the washed 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 (4a) as a dark yellow liquid (10.3g). The yield of the product was 88.4%.
Example 3: Preparation of diester in accordance with the present disclosure
The lubricity additive compositions were prepared using 2-Hexen-1-ylsuccinic anhydride similar to the process disclosed in Example 2 by varying the alcohols, the resultant compounds are provided below in Table 2.
Table 2: Diesters produced by corresponding alcohols
Alcohol Obtained Product
n-Octanol
C8H17OH
4a
Ethanol
C2H5OH
4b
n-Hexadecanol
C16H33OH
4c

Experiment II: Preparation of diester product from light cracked naphtha (LCN) in accordance with the present disclosure
Light cracked naptha (LCN)was maleated by using maleic anhydride to obtain alkenyl succinic anhydride, followed by esterification with alcohol to produce a diester product. A schematic representation of the process for the preparation of diester product from LCN was given as scheme II
SCHEME II
Example 4: Maleation of light cracked naphtha (LCN)
600 g of light cracked naphtha (LCN) and 247 g of maleic anhydride were charged into the high-pressure reactor and purged with nitrogen gas for 10 minutes followed by slowly raising the temperature to 200 °C to obtain a reaction mixture. The reaction mixture was cooled and kept overnight to allow unreacted maleic anhydride to settle in the bottom. The reaction mixture was filtered and concentrated by a rotary evaporator to remove the unreacted 1-hexene and other hydrocarbons to obtain alkenyl succinic anhydride (6) as a maleated LCN. The yield of the product was 70%.
Example 5: Preparation of diester product with ethanol
5 g of maleated LCN was mixed with 2.5 g of ethanol followed by 0.5 g of p-toluenesulphonic acid (PTSA) and 40 mL of toluene to obtain a reaction mixture. The reaction mixture was refluxed at 110 °C for 9 hours with constant stirring. The water liberated during the reaction was removed at regular intervals. The reaction was monitored by using thin-layer chromatography. After completion of the reaction, the reaction mixture was cooled at room temperature. The reaction mixture was mixed with 50ml ethyl acetate to obtain the resultant mixture. The so obtained resultant mixture was allowed to settle and the ethyl acetate layer is separated to obtain a first separated ethyl acetate layer. The first separated ethyl acetate layer was washed with excess water and separated to obtain the washed ethyl acetate layer. The moisture in the washed ethyl acetate layer was removed using anhydrous sodium sulphate to obtain a moisture free ethyl acetate layer. The ethyl acetate was removed from moisture free ethyl acetate layer under vacuum to obtain the lubricity additive composition (7a) as a dark yellow liquid. The yield of the product was85%.
Example 6: Preparation of diester product with 1-decanol
5 g of maleated LCN was mixed with 9.6 g of 1-decanol followed by 0.5 g of p-toluenesulphonic acid (PTSA) and 40 mL of toluene to obtain a reaction mixture. The reaction mixture was refluxed at 110 °C for 9 hours with constant stirring. The water liberated during the reaction was removed at regular intervals. The reaction was monitored by using thin-layer chromatography. After completion of the reaction, the reaction mixture was cooled at room temperature. The reaction mixture was mixed with 50mL ethyl acetate to obtain the resultant mixture. The so obtained resultant mixture was allowed to settle and the ethyl acetate layer is separated to obtain a first separated ethyl acetate layer. The first separated ethyl acetate layer was washed with excess water and separated to obtain the washed ethyl acetate layer. The moisture in the washed ethyl acetate layer was removed using anhydrous sodium sulphate to obtain a moisture free ethyl acetate layer. The ethyl acetate was removed from moisture free ethyl acetate layer under vacuum to obtain the lubricity additive composition (7f) as a dark yellow liquid. The yield of the product was 85%.
Example 7: Synthesis of diester products
The maleated LCN obtained in Example 4was esterified using a similar process disclosed in Example 5 by varying the alcohols, the resultant diester products are provided below in Table 3.

Table 3: Diester products produced by corresponding alcohols
Alcohol Obtained product

Ethanol
C2H5OH
7a
1-Butanol
C4H9OH
7b
1-Hexanol
C6H13OH
7c
2-Ethyl hexanol
C8H17OH
7d
1-Octanol
C8H17OH
7e
1-Decanol
C10H21OH
7f
1-Tettradecanol
C14H29OH
7g
1-Hexadecanol
C16H33OH
7h
Wherein, R, R1= H, alkyl or aryl groups
Example 8:

The so obtained diester 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 4.

Table 4: WSD of diester product
HFRR 60°C, 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
4a 150 521 475 498 300 515 470 493
4b 150 504 460 482 300 498 455 477
4c 150 465 422 443 300 445 401 423
7a 150 525 478 502 300 520 478 499
7b 150 520 470 495 300 504 458 481
7c 150 502 455 479 300 486 437 462
7d 150 475 431 453 300 462 418 440
7e 150 492 448 470 300 482 441 461
7f 150 475 445 460 300 450 414 432
7g 150 452 421 437 300 436 395 416
7h 150 432 402 417 300 420 378 399
The maximum allowed limit for the lubricity value of BS-VI ULSD is 460 µm. The ULSD blended with the diester 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 was directly related to the lubrication property of the sample.
It is evident from the above data, that diesterproducts4c, 7d, 7f, 7g, and 7h are suitable as lubricity additives for ULSD.

TECHNICAL ADVANCEMENTS
The present disclosure described hereinabove 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 in 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 a diester 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 diester product of mixture of olefins.
5. A process for preparing a lubricity additive composition comprising a diester product, said process comprising the following steps:
a) maleating at least one olefin with maleic anhydride in an inert atmosphere at a first predetermined temperature for a first predetermined time period under stirring to obtain a reaction mixture comprising a maleated product of said olefin;
b) adding at least one alcohol to the maleated 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 a diester product of said olefin and unreacted alcohol; and
c) separating the diester 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 inert atmosphere is selected from nitrogen or argon.
8. The process as claimed in claim 5, wherein said first predetermined temperature is in the range of 150 °C to 250°C.
9. The process as claimed in claim 5, wherein said first predetermined time period is in the range of 7 hours to 10 hours.
10. The process as claimed in claim 5, wherein said stirring in step a) is carried out at a speed in the range of 500 rpm to 700 rpm.
11. The process as claimed in claim 5, wherein said alcohol is at least one selected from the group consisting of ethanol, n-octanol, n-hexadecanol, 1-butanol, 1-hexanol, 2-ethyl hexanol, 1-octanol, 1-decanol, 1-tetradecanol, and 1-hexadecanol.
12. The process as claimed in claim 5, wherein said acid catalyst is selected from the group consisting of p-toulenesulphonic acid (PTSA).
13. The process as claimed in claim 5, wherein said second predetermined temperature is in the range of 90°C to 130 °C.
14. The process as claimed in claim 5, wherein said second predetermined time period is in the range of 8 hours to 12 hours.
15. The process as claimed in claim 5, wherein a ratio of said maleated product of the olefin to the alcohol is in the range of 1:2.
16. 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 obtain a washed separated organic layer;
d) removing s moisture from said washed organic layer by using anhydrous sodium sulphate to obtain a moisture free organic layer;
e) removing the organic fluid medium from said moisture free organic layer under vacuum to obtain the lubricity additive composition.
17. The process as claimed in claim 16, wherein said organic fluid medium is ethyl acetate.
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.