DESC:FIELD OF THE INVENTION:
The present invention broadly relates to the field of fuel sciences and fuel additives. In particular, the present invention provides for additive composition which acts as a fuel stabilizer to provide stable alkanol-diesel blends. The present invention also provides fuel blends comprising the additive composition and methods of synthesis thereof.

BACKGROUND OF THE INVENTION:
Middle distillates or conventional diesel fuels are typically higher boiling paraffinic hydrocarbons optimized for a cetane rating of 51 minimum. Generally, diesel fuels contain negligible amount of lower vapor pressure species such as aromatic and unsaturated hydrocarbons. Globally diesel fuels are used for combustion, to heat and power a wide variety of stationary structures and machines and moving vehicles for example, buildings, power generators, farm equipment, passenger cars, buses, trucks, construction equipment, aircraft and ships. In order to reduce dependence on fossil hydrocarbon fuels and to improve air quality, recent research has been focusing on alternative fuels and oxygenates blended conventional fuels. In the hydrocarbon fuel sector, fuel compositions have been proposed containing an alcoholic fraction, especially one of low-alkyl alcohols like methanol and ethanol, which are in principle obtainable from renewable resources. However, the problems associated with such fuel compositions (alcohol-diesel) are related to non-solubility of lower alcohols in diesel blends, low temperature stability of blends, sensitivity to water ingress, lower cetane rating and poor storage stability. Since lower alcohols are highly hygroscopic, the fuel blends pick up water/moisture during transport and storage, hence, alcohol-diesel blends are very tricky to handle. Due to limited miscibility of alcohol fractions in diesel, additive coupler is needed to stabilize the alcohol-diesel blends. To compensate cetane loss of blends, appropriate type and amount of Cetane Improver can be added to the alcohol-diesel blends. The most difficult problems of such alcohol-diesel blends are their lower water tolerance and high sensitivity to phase separation characteristics.

US application no. 20040093789 covers the compositions to stabilize emulsion of hydrocarbon fuel, alcohol and water concentrations for preventing phase separation, which consists of a blend of two or more wide and one or more tall giant hydrophobic nonionic surfactants.

US7473283 covers the use of fuel additive composition for stabilizing blends of ethanol and a hydrocarbon boiling in the gasoline or diesel range, comprising 0.1-10% of Cashew Nutshell Liquid (CSNL) derivative(s) or mixtures of organic co-solvent depending upon the percentage composition of diesel and ethanol blend and the additive composition is specific for ethanol-diesel blends.

US7427303 discloses surfactant composition including ethoxylate of CNSL for use as an emulsifier in water blended fuel mixture wherein the said composition includes ethoxylate of cashew nutshell liquid and the composition comprises of a co-surfactant having a hydrophilic lipophilic balance in the range of 4 to 12 and a polymeric dispersant.

U.S. Pat. Nos. 6190427, 6017369, 7311739 and 7172635, describe the compositions of diesel fuel and ethanol, a mixture of ethoxylated fatty alcohols and ethanolamides.

U.S. Pat. No. 4,451,265 describes a blended fuel comprising a diesel fuel, a lower (C1-C3) alcohol, water and a surfactant system derived from the reaction product of N, N-dimethyl amine and a long-chain fatty acid substance wherein the result product is emulsified.

McCormick and Parish, “Advanced Petroleum Base Fuels Program and Renewable Diesel Program,” NREL/MP-540-32674, November 2001, published report on ethanol in diesel fuel (E-Diesel). The report describes the physical properties of 15% ethanol/diesel blends that contain emulsifiers as having lower flash points. This change in property of the fuel results in a change from a Class II liquid to a Class I liquid.

Further, L. R. Waterland et al, “Safety and Performance Assessment of Ethanol/Diesel Blends (E-Diesel), NREL/SR-540-34817, September 2003, published report to review the safety and performance aspects of ethanol/diesel blends, citing five additive (emulsifier) vendors: Pure Energy, a blend of alkyl esters of fatty acids, fatty acid alcohols and a polymer; O2 Diesel (formerly AAE Technologies) alkanolamides; Akzo Nobel with a proprietary agent called Beraid ED10; Lubrizol and GE Betz, with a phosphite-based additive.

US 20130255141A1 covers the use of fuel oil and its preparation methods by splash blending of ethanol into diesel fuel. The additive composition described for the miscibility of ethanol in diesel phase at room temperature.

However, the prior art does not discuss the solubility & low temperature stability of alcohol-diesel blends, especially C1 alcohol –diesel blends which results in fuel instability due to phase separation.

OBJECTIVE OF THE INVENTION:
It is a primary objective of the present invention to provide alcohol-hydrocarbon fuel stabilizer compositions.

It is a further objective of the present invention to provide a method for producing the alcohol-hydrocarbon fuel stabilizer compositions.

Further, another objective of the present invention is to provide stabilizer compositions that are cost effective and made from indigenous components.

Further, another objective of the present invention is to provide fuel blends that are not temperature sensitive making it easily transportable.

Further, yet another objective of the present invention is to provide novel additive composition that is compatible with other fuel additives and enhances the quality of diesel fuel.

SUMMARY OF THE INVENTION:
The present invention provides an additive composition for solubilizing lower alcohols in diesel fuel, comprising: 60 to 90% w/w of aliphatic alcohol with (C4-C20); 0.5 to 5% w/w of fatty acid based lubricity improver with (C14 - C20); and 0.5 to 5% w/w of polyetheramine based polydispersant with (C12 - C24),
wherein the diesel fuel is an ultra-low sulphur diesel fuel.

The lubricity improver is selected from Ester based lubricity improver compatible with diesel.

The polydispersant has molecular weight in a range of 800 to1200 and wherein the molecular weight is preferably 1000.

The composition optionally comprises a cetane improver selected from a group consisting of 2-ethyl hexyl nitrate, H2O2 based cetane improver or a combination thereof.

The composition optionally comprises a corrosion inhibitor compatible with alcohol-diesel blends.

The present invention also provides a method of producing the additive composition, comprising: blending of alcohols (C4 - C20) preferably C8 - C12 in specific ratios at ambient temperature in a range of 25 to 35 °C with stirring; adding fatty acid based lubricity improver to the blend of alcohols; and adding polymeric dispersant preferably polyetheramine (polyEA) having ~1000 MW with C12 - C24 to the mixture of alcohols and fatty acid with continuous stirring.
The method comprises optionally adding a cetane improver and a corrosion inhibitor to the additive composition.

The cetane improver is selected from a group consisting of 2-ethyl hexyl nitrate, H2O2 based cetane improver or a combination thereof.

The corrosion inhibitor is compatible with alcohol - diesel blends.

Further, the present invention provides a fuel blend comprising diesel fuel, aliphatic alcohols (C4 - C16), and additive composition, wherein the fuel blend comprises: 60 to 90% v/v of the diesel fuel; 5 to 40% v/v of the alcohol (C1 - C4); and up to 40% v/v of the additive composition.

The ratio of diesel fuel: alcohol: additive composition is 74-94: 5-20:0.25-12.

The fuel blend comprises Biodiesel and wherein the ratio of diesel fuel: biodiesel: alcohol: additive composition is 73-87:7:5-15:0.25-10.

The additive composition when present in a range of 0.1 to 20% v/v improves the solubility and dispersibilty of lower alcohols by up to 50%, v/v.

DETAILED DESCRIPTION OF THE INVENTION:
The present disclosure broadly provides for cost-effective additive composition to solubilize lower alcohols in ultra-low sulfur diesel (ULSD) fuel blends which is applicable to blend C1 - C4 alcohols in diesel at lower treat rate and it also leads to improved cetane number, lubricity performance and storage stability of blended fuels as per the fuel specifications requirements. The present disclosure also pertains to the method of producing the additive composition and fuel blend thereof.

For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiment illustrated in the drawings and specific language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated system, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skilled in the art to which this invention belongs. The system, methods, and examples provided herein are illustrative only and not intended to be limiting.

Although any methods and materials similar or equivalent to those described herein can also be used in the practice or testing of the present invention, the preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference to disclose and describe the methods and/or materials in connection with which the publications are cited.

It must be noted that as used herein and in the appended claims, the singular forms "a", "and", and "the" include plural referents unless the context dictates otherwise. Thus, for example, reference to "a compound" includes a plurality of such compounds, and reference to "the step" includes reference to one or more steps and equivalents thereof known to those skilled in the art, and so forth.

The term “some” as used herein is defined as “none, or one, or more than one, or all”. Accordingly, the terms “none”, “one”, “more than one”, “more than one, but not all” or “all” would all fall under the definition of “some”. The term “some embodiments” may refer to no embodiments or to one embodiment or to several embodiments or to all embodiments. Accordingly, the term “some embodiments” is defined as meaning “no embodiment, or one embodiment, or more than one embodiment, or all embodiments”.

The terminology and structure employed herein is for describing, teaching and illuminating some embodiments and their specific features and elements and does not limit, restrict or reduce the spirit and scope of the claims or their equivalents.

More specifically, any terms used herein such as but not limited to “includes”, “comprises”, “has”, “consists” and grammatical variants thereof is inclusive or open-ended and does not exclude additional, unrecited elements or method steps. The specification will be understood to also include embodiments which have the transitional phrase “consisting of” or “consisting essentially of” in place of the transitional phrase “comprising”. The transitional phrase “consisting of” excludes any element, step, or ingredient not specified in the claim, except for impurities associated therewith. The transitional phrase “consisting essentially of” limits the scope of a claim to the specified materials or steps “and those that do not materially affect the basic and novel characteristic(s)” of the claimed invention.

Whether or not a certain feature or element was limited to being used only once, either way it may still be referred to as “one or more features” or “one or more elements” or “at least one feature” or “at least one element”. Furthermore, the use of the terms “one or more” or “at least one” feature or element do NOT preclude there being none of that feature or element, unless otherwise specified by limiting language such as “there NEEDS to be one or more” or “one or more element is REQUIRED”.

Unless otherwise defined, all terms, and especially any technical and/or scientific terms, used herein may be taken to have the same meaning as commonly understood by one having an ordinary skill in the art.

Reference is made herein to some “embodiments”. It should be understood that an embodiment is an example of a possible implementation of any features and/or elements presented in the attached claims. Some embodiments have been described for the purpose of illuminating one or more of the potential ways in which the specific features and/or elements of the attached claims fulfil the requirements of uniqueness, utility and non-obviousness.

Use of the phrases and/or terms such as but not limited to “a first embodiment”, “a further embodiment”, “an alternate embodiment”, “one embodiment”, “an embodiment”, “multiple embodiments”, “some embodiments”, “other embodiments”, “further embodiment”, “furthermore embodiment”, “additional embodiment” or variants thereof do NOT necessarily refer to the same embodiments. Unless otherwise specified, one or more particular features and/or elements described in connection with one or more embodiments may be found in one embodiment, or may be found in more than one embodiment, or may be found in all embodiments, or may be found in no embodiments. Although one or more features and/or elements may be described herein in the context of only a single embodiment, or alternatively in the context of more than one embodiment, or further alternatively in the context of all embodiments, the features and/or elements may instead be provided separately or in any appropriate combination or not at all. Conversely, any features and/or elements described in the context of separate embodiments may alternatively be realized as existing together in the context of a single embodiment.

As used herein, the term "about" is used to indicate a range or approximation that allows for slight variations or deviations from a specific value or parameter without departing from the scope of the present invention. When "about" is used in conjunction with numerical values, it signifies that the disclosed value or parameter may vary by ±10%, preferably ±5%, of the indicated values.

As used herein, the terms “method” and “process” have been used interchangeably.

As used herein, the terms “additive package”, “additive composition”, “stabilizer”, “stabilizer composition” and “coupler” have been used interchangeably.

As used herein, the terms “fuel blend”, “fuel composition” have been used interchangeably.

The present invention provides for an additive composition to solubilize lower alcohols in ultra -low sulfur diesel (ULSD) fuel blends.

In some embodiments, the additive composition of the present invention provides stable alkanol-diesel blends which acts as a fuel stabilizer.

In some embodiments, the additive composition of the present invention comprises C4 to C20 aliphatic alcohols, a polymeric dispersant preferably having ~1000 MW with C12 to C24.

In some embodiments, the additive composition or coupler of the present invention comprises:
(i) about 60 to 90% w/w of alcohol (C4-C20)
(ii) about 0.5 to 5% w/w of fatty acid based lubricity improver with (C14 - C20); and
(iii) about 0.5 to 5% w/w of polyetheramine based dispersant having ~ 1000 MW with C12 - C24.
wherein the diesel fuel is an ultra-low sulphur diesel fuel.

In some embodiments, the additive composition or coupler of the present invention comprises:
(i) 60 to 90% w/w of alcohol (C4-C20)
(ii) 0.5 to 5% w/w of fatty acid based lubricity improver with (C14 - C20); and
(iii) 0.5 to 5% w/w of polyetheramine based dispersant having ~ 1000 MW with C12 - C24.
wherein the diesel fuel is an ultra-low sulphur diesel fuel.

In an embodiment of the present invention, the lubricity improver is selected from Ester based lubricity improver compatible with diesel.

In an embodiment of the present invention, the polydispersant has a molecular weight in a range of 800 to 1200 and wherein the molecular weight is preferably 1000.

In an embodiment of the present invention, the composition optionally comprises a cetane improver selected from a group consisting of 2-ethyl hexyl nitrate, H2O2 based cetane improver or a combination thereof.

In an embodiment of the present invention, the composition optionally comprises corrosion inhibitor compatible with alcohol-diesel blends.

In an aspect the present invention provides a method of producing the additive composition, comprising:
i. blending of alcohols (C4 - C20) preferably C8 - C12 in specific ratios at ambient temperature in a range of 25 to 35 °C with stirring; and
ii. adding fatty acid based lubricity improver to the blend of alcohols; and
iii. adding polymeric dispersant preferably polyetheramine (polyEA) having ~1000 MW with C12 - C24 to the mixture of alcohols and fatty acid with continuous stirring.

In another embodiment of the present invention, the method comprises optionally adding a cetane improver and a corrosion inhibitor to the additive composition.

The additive composition of the present invention is suitable for blending lower alkanol (C1 – C4) in diesel. In some embodiments, the additive composition solubilizes lower alkanol (C1 – C4) in diesel at lower treat rate, leads to improved cetane number, lubricity performance and storage stability of blended fuels as per the fuel specifications requirements.

The present disclosure also pertains to the method of producing the additive composition of the present invention.

In some embodiments, the method of producing the additive composition comprises:
- blending of alcohols (C4 - C20) in specific ratios at ambient temperature in a range of 25 to 35 °C with stirring,
- adding fatty acid based lubricity improver to the blend of alcohols.
- adding polymeric dispersant preferably polyetheramine (polyEA) having ~1000 MW with C12 - C24 to the mixture of alcohols and fatty acids with continuous stirring,
- optionally adding optimized dosage of cetane improver and corrosion inhibitor with stirring, to obtain the additive composition of the present invention.

The present disclosure also pertains to fuel blends comprising the additive composition or coupler of the present invention.

In some embodiments, the fuel blend comprises diesel fuel, aliphatic alcohols and coupler.

In the composition embodiment, the fuel blend contains up to 40% by volume of the coupler or additive composition of the present invention.

In another embodiment, the fuel blend contains 5 to 40% by volume of short chain alkanol (C1-C4).

In yet another aspect, the fuel blend of the present invention has amounts of the diesel fuel, alcohol and additive composition as:
(a) 60 to 90% v/v of the diesel fuel;
(b) 5 to 40% v/v of the alcohol (C1 - C4); and
(c) up to 40% v/v of the coupler.

In yet another embodiment, the fuel blend of the present invention has amounts of the diesel fuel, alcohol and additive composition as:
(a) 60 to 90% v/v of the diesel fuel;
(b) 5 to 40% v/v of the alcohol (C1 - C4); and
(c) 1 to 40% v/v of the additive composition.

In another embodiment of the present invention, the ratio of diesel fuel: alcohol: additive composition is 74-94: 5-20:0.25-12.

In another embodiment of the present invention, the fuel blend comprises Biodiesel and wherein the ratio of diesel fuel: biodiesel: alcohol: additive composition is 73-87:7:5-15:0.25-10.

In another embodiment of the present invention, the additive composition when present in a range of 0.1 to 20% v/v improves the solubility and dispersibilty of lower alcohols by up to 50%, v/v,

The additive composition applied for blending of lower alcohols (C1 – C4) in ultra-low sulphur diesel (ULSD) at dosage range of 0.1 to 20% v/v helps in solubility of lower alcohols (C1 – C4) in ULSD, thereby alcohol-diesel blends obtained are found to be stable at low temperature. The additive composition of the present invention enhances the dispersability of alkanol in hydrocarbon matrix up to 50% v/v with improved blend stability at low temperature, water tolerance and corrosion protection. Besides the stability of alcohol-diesel blends, the additive composition doped diesel fuel showed improvement in critical properties like cetane no., lubricity and storage stability.

According to a main embodiment, the present invention provides for the fuel blend comprising diesel fuel, aliphatic alcohols (C1 - C4), and additive composition, wherein the amounts of the diesel fuel, alcohol and additive composition in the blend are:
(a) 60 to 90% of the diesel fuel;
(b) 5 to 40% v/v of the alcohol (C1 - C4); and
(c) up to 40% v/v of the coupler,
wherein alcohol and the additive composition are present in the blend, and the additive composition comprises:
(i) about 60 to 90% w/w of alcohol (C4-C20),
(ii) about 0.5 to 5% w/w of fatty acid based lubricity improver with (C14 - C20); and
(iii) about 0.5 to 5% w/w of polyetheramine based polydispersant having ~ 1000 MW with C12 - C24.

According to a main embodiment, the present invention provides for the fuel blend comprising diesel fuel, aliphatic alcohols (C1 - C4), and a coupler, wherein the amounts of the diesel fuel, alcohol and coupler in the blend are:
(a) 60 to 90% of the diesel fuel;
(b) 5 to 40% v/v of the alcohol (C1 - C4); and
(c) up to 40% v/v of the coupler,
wherein alcohol and the coupler are present in the blend, and the coupler comprises:
(i) 60 to 90% w/w of alcohol (C4-C20),
(ii) 0.5 to 5% w/w of fatty acid based lubricity improver with (C14 - C20); and
(iii) 0.5 to 5% w/w of polyetheramine based polydispersant having ~ 1000 MW with C12 - C24.

In some embodiments, the additive composition or coupler of the present invention improves stability of alcohol-diesel fuel blends containing 5 to 40% by volume of short chain alkanol (C1-C4).

The present disclosure also pertains to method of producing the fuel blend or the fuel blend composition of the present invention employing the additive composition of the present invention.

Ester based lubricity improver includes biodiesel.

H2O2 based cetane improver includes Di-Tertiary Butyl Peroxide (DTBP).

Technical advantages of the present invention:
In some embodiments, advantages of the present invention over the prior arts include but are not limited to the following:
• Improved flow properties, improved storage stability of blends, better lubricity
performance and corrosion protection characteristics of diesel fuel blends.
• Improved quality of the blended diesel fuel for critical properties like cetane number, lubricity, corrosion protection and enhanced storage stability.
• Excellent miscibility with alcohol-diesel blends.
• Compatible with all the existing fuel additives doped in diesel like cold flow improver, dehazer, cetane improver, detergent-dispersant etc.

The present invention is further illustrated by reference to the following examples which is for illustrative purpose only and does not limit the scope of the invention in any way. These examples are not intended to be inclusive of all aspects of the subject matter disclosed herein, but rather to illustrate representative features, methods, compositions, and results. These examples are not intended to exclude equivalents and variations of the present invention, which are apparent to one skilled in the art.

EXAMPLES:
The following examples are provided to demonstrate the invention but are not intended to limit the scope of the invention. Specifically, the following examples are provided to illustrate the composition, manufacture and physical characteristics of the inventive fuel composition containing alkanol (C1-C4) and the additive composition which meet the physio-chemical specifications of alcohol-diesel fuel blends.
Materials and methods:
Following components (chemicals) were used for the development of novel and effective additive composition for blending of lower alcohols (C1 – C4) in ULSD at dosage range of 0.1 to 20% v/v thereby alcohol-diesel blends found stable at low temperature, a polymeric dispersant having ~1000 MW with C12 - C24 (10: 2.5: 1.0). The additive composition applied for blending of lower alkanols (C1 – C4) in ultra-low sulphur diesel (ULSD) at dosage range of 0.1 to 20%, v/v help in the solubility of lower alcohols up to 50%, v/v. The performance of additive formulations prepared using different components are discussed in examples given below.

Component A: Aliphatic alcohols C4 - C20 were purchased from commercial suppliers, India
Component B: A commercial poly-etheramine based dispersant having ~1000 MW with carbons numbers from C12 - C24
Component C: Fatty acid based Lubricity improver used.
Component D: Cetane improver, 2-ethyl hexyl nitrate purchased from commercial vendor.
Component E: Corrosion inhibitor in-house developed formulation.
Component F: Anhydrous methanol meeting Indian specification (IS: 17075-2019)
Component G: Anhydrous ethanol meeting Indian specification (IS: 15464-2022)
Component H: Automotive Diesel meeting Indian specification IS: 1460-2017
Component I: Bio-Diesel meeting Indian specification IS: 15607-2022

Example 1: Preparation process of additive composition/package
The additive package prepared after evaluating different combinations of components of different chemistry and established the compatibility and superior activity. The invented additive package formulated using optimized ratios of components. The additive package was prepared by blending alcohols (C8 - C12) in specific ratios at ambient temperature between 25 to 35 °C with stirring. To the blend of alcohols is added fatty acid based lubricity improver. To the mixture of alcohols and fatty acid is added polymeric dispersant which is polyetheramine (polyEA) having ~1000 MW with C12 - C24 with continuous stirring. To this mixture optionally added optimized dosage of 2-ethyl hexyl nitrate and Corrosion Inhibitor with stirring.

Following additive formulations were prepared using different components in different ratios to optimize high performing additive package:

Table 1: List of additive formulations prepared using different components
S. No. Formulation/Coupler Components ULSD: MeOH/EtOH: Coupler Properties
Appearance / layer Flash point, °C Blend stability temp, °C
1 C4 - C20 alcohols 85:10:1-8 Hazy- Two layers 9.8 Not stable
2 OSP-18 (polyalkylene glycol) 80:10:5-10 Hazy- Two layers 9.5 Not stable
3 C4 - C20, FA (C12-C24) 73-75:15:8-10 Hazy 9.8 Not stable
75:15:8-10 Hazy- Two layers 9.5 Not stable
4 C4-C8 alcohols 75:15:8-10 Hazy- Two layers 9.8 Not stable
5 C6- C8 alcohols 75:15:8-10 Hazy- Two layers 9.8 Not stable
6 C4 -C20, Lubolic -20 77:15:5-8 Hazy- Two layers 9.5 Not stable

7 C4 -C20, Tall Oil 75:15:8-10 Hazy- Two layers 9.5 Not stable
8 C4 - C20, Tall Oil 76:15:7-9 Hazy- Two layers 9.5 Not stable
9 C4 - C20, TOFA 71:15:14 Clear blend 9.8 Stable up to
25-30°C
(increase in acidity)
10 C4-C20 in combinations 75:15: 5-10 Hazy 9.5 Not stable
11 Sodium Potassium sulfonate/ Span-60, Isobutanol/ Isoamyl alcohol/ Dibutoxy phosphate, GMO, 2- Butoxy Ethanol 73-80:15: 5-8
Hazy- Two layers
9.5 Not stable
12 C8/C9/C10/C12/ C4 + PolyEA 75:15:8-11 Clear blend 9.5 Stable up to 15°C
13 C8/C9/C10/C12/ + PolyEA + FA 75:15: 8-11 Clear blend 9.5 Stable up to 15°C
14 C8/C9/C10/C12/ + PolyEA + FA 75:15: 8-11 Clear blend 9.5 Stable up to 15°C
15 C8/C9/C10/C12/ + PolyEA + FA + 2-EHN 82:10: 6-8 Clear blend 9.5 Stable up to 15°C
16 C8/C9/C10/C12/ + 2-EHN+ FA 74-78:15:8-11 Clear blend 9.5 Stable up to 15°C
18 C8/C9/C10/C12/ + PolyEA + FA 74-78:15:8-11 Clear blend 9.5 Stable up to 15°C
19 C8/C9/C10/C12/ + PolyEA + FA + 2-EHN 75:15:12 Clear blend 9.5 Stable up to 15°C
20 C8/C12+ PolyEA + FA 75.5-94: 5-20: 0.5-5 Clear blend 11 Stable up to 8°C
21 C8/C12+ PolyEA +FA + 2-EHN 94:5:1 Clear blend 11 Stable up to 8°C
22 C8/C12+ PolyEA + 2-EHN 94.25:5:0.75 Clear blend 11 Stable up to 8°C
23 C8/C12+ PolyEA +FA + 2-EHN 88.5:10:1.5 Clear blend 11 Stable up to 8°C
24 C8/C12+ PolyEA + 2-EHN 86:12:2 Clear blend 11 Stable up to 8°C
25 C8/C12+ PolyEA+ FA + 2-EHN 82:15:3 Clear blend 11 Stable up to 8°C
ULSD: BD: MeOH/EtOH: Coupler
26 C4-C20+ PolyEA + FA 73:7: 15:5-10 Clear blend 9.5 Stable up to 10°C
27 C4-C20+ PolyEA + FA 87:7: 5:0.25-3 Clear blend 11 Stable up to 8°C
28 C4-C20+ PolyEA + FA 82:7: 10:0.25-5 Clear blend 11 Stable up to 8°C
*C4 to C12 alcohols, FA-fatty acid, 2-EHN (2- Ethyl Hexyl Nitrate), BD-Biodiesel

Example 2:
Hydrocarbon diesel fuel (at about 80 to 85% vol) is placed in a 1 litre container at ambient temperature and pressure. Methanol (at about 10 to 15% vol) is added to the flask creating an oil phase and an alcohol phase. Then individual alcohols (C4 - C20) are added alone at 1 to 10% vol separately in each case and a stopper is applied to the top of the container and the resultant mixture is shaken for about one minute to allow proper mixing of the liquids to take place and a single phase to form. The resultant fuel blends as obtained were found unstable at about 25-30° C i.e., ambient temperature and pressure.

Example 3:
Hydrocarbon diesel fuel (at about 80 to 95% vol) is placed in a 1 litre container at ambient temperature and pressure. Methanol (at about 10 to 15% vol) is added to the flask creating an oil phase and an alcohol phase. Then individual fatty acid or mixture of fatty acids having alkyl chain of 14-20 carbon atoms is added alone at about 0.5 to 10% vol separately in each case and a stopper is applied to the top of the container and the resultant mixture is shaken for about one minute to allow proper mixing of the liquids to take place and a single phase to form. The resultant fuel blends as obtained were found unstable at ambient temperature and pressure (results not shown in table 1).

Example 4:
Hydrocarbon diesel fuel (at about 80 to 95% vol) is placed in a 1 litre container at ambient temperature and pressure. Methanol (at about 10 to 15% vol) is added to the flask creating an oil phase and an alcohol phase. Then added about 0.5 to 5% by weight of polyether amine (polyEA) having ~ 1000 MW having alkyl chain of 14-20 carbon atoms alone at about 0.5 to 10% vol separately in each case and a stopper is applied to the top of the container and the resultant mixture is shaken for about one minute to allow proper mixing of the liquids to take place and a single phase to form. The resultant fuel blends as obtained were found unstable at about 25-30°C i.e., ambient temperature and pressure (results not shown in table 1).

Example 5:
Hydrocarbon diesel fuel (at about 80% vol) is placed in a 1 litre container at ambient temperature and pressure. Methanol (at about 10% vol) is added to the flask creating an oil phase and an alcohol phase. Then added formulation of S. No. 1 to 2 at about 10% vol separately in each case and a stopper is applied to the top of the container and the resultant mixture is shaken for about one minute to allow proper mixing of the liquids to take place and a single phase to form. The resultant fuel blends as obtained with formulation of S. No. 1 & 2 were found unstable at ambient temperature and pressure.

Example 6:
Hydrocarbon diesel fuel (at about 71 to 75% vol) is placed in a 1 litre container at ambient temperature and pressure. Methanol (at about 15% vol) is added to the flask creating an oil phase and an alcohol phase. Then added formulation of S. No.3 to 8 at about 8 to 10% vol separately in each case and a stopper is applied to the top of the container and the resultant mixture is shaken for about one minute to allow proper mixing of the liquids to take place and a single phase to form. The resultant fuel blends as obtained with formulation of S. No. 3 to 8 were found unstable at ambient temperature and pressure.

Example 7:
Hydrocarbon diesel fuel (at about 71% vol) is placed in a 1 litre container at ambient temperature and pressure. Methanol (at about 15% vol) is added to the flask creating an oil phase and an alcohol phase. Then added formulation of S. No. 9 at about 10 to 14% vol separately in each case and a stopper is applied to the top of the container and the resultant mixture is shaken for about one minute to allow proper mixing of the liquids to take place and a single phase to form. The resultant fuel blends obtained were found stable at ambient temperature and pressure but blend having increased acidity.

Example 8:
Hydrocarbon diesel fuel (at about 73 to 80% vol) is placed in a 1litre container at ambient temperature and pressure. Methanol (at about 10 to 15% vol) is added to the flask creating an oil phase and an alcohol phase. Then added formulation of S. No. 11 to 19 at about 10 to 12% vol separately in each case and a stopper is applied to the top of the container and the resultant mixture is shaken for about one minute to allow proper mixing of the liquids to take place and a single phase to form. The resultant fuel blends obtained were found stable up to 15°C.

Example 9:
Hydrocarbon diesel fuel (at about 73 to 80% vol) is placed in a 1 litre container at ambient temperature and pressure. Methanol (at about 15% vol) is added to the flask creating an oil phase and an alcohol phase. Then added formulation of S. No. 10 to 11 at about 5 to 10% vol separately in each case and a stopper is applied to the top of the container and the resultant mixture is shaken for about one minute to allow proper mixing of the liquids to take place and a single phase to form. The resultant fuel blends obtained with formulation of S. No. 10-11 were found unstable with layer separation.

Example 10:
Hydrocarbon diesel fuel (at about 82 to 94.5% vol) is placed in a 1 litre container at ambient temperature and pressure. Ethanol (at about 5 to 15% vol) is added to the flask creating an oil phase and an alcohol phase. Then added formulation of S. No. 20 to 25 at about 0.5 to 5% vol separately in each case and a stopper is applied to the top of the container and the resultant mixture is shaken for about one minute to allow proper mixing of the liquids to take place and a single phase to form. The resultant fuel blends obtained were stable from zero to -10°C.

Example 11:
Hydrocarbon diesel fuel (at about 7 to 82% vol) and biodiesel (at about 7% vol) are placed in a 1 litre container at ambient temperature and pressure. Methanol (at about 15% vol) is added to the flask creating an oil phase and an alcohol phase. Then added formulation of S. No. 11-19 at about 3 to 8% vol separately in each case and a stopper is applied to the top of the container and the resultant mixture is shaken for about one minute to allow proper mixing of the liquids to take place and a single phase to form. The resultant fuel blends obtained with formulation of S. No. 11-19 were found stable up to 8°C.

Example 12:
Hydrocarbon diesel fuel (at about 82 to 94.5% vol) is placed in a 1 litre container at ambient temperature and pressure. Ethanol (at about 5 to 15% vol) is added to the flask creating an oil phase and an alcohol phase. Then added formulation of S. No. 20 - 25 at about 0.25 to 3% vol separately in each case and a stopper is applied to the top of the container and the resultant mixture is shaken for about one minute to allow proper mixing of the liquids to take place and a single phase to form. The resultant fuel blends obtained with formulation of S. No. 20-25 were found stable up to 8°C.

Example 13:
Hydrocarbon diesel fuel (at about 76 to 87.5% vol) and biodiesel (at about 7% vol) are placed in a 1 litre container at ambient temperature and pressure. Ethanol (at about 5 to 15% vol) is added to the flask creating an oil phase and an alcohol phase. Then added formulation of S. No. 26 - 28 at about 0.25 to 3% vol separately in each case and a stopper is applied to the top of the container and the resultant mixture is shaken for about one minute to allow proper mixing of the liquids to take place and a single phase to form. The resultant fuel blends obtained with formulation of S. No. 26-28 were found stable up to 8°C.

Example 14: Storage stability of alcohol-diesel blends
Further selected stable blends were subjected to storage stability for 3-6 months and results are depicted in table 2.

Table 2: Storage stability of alcohol-diesel blends with time
S. No. Blend composition
(ULSD: MeOH/EtOH: Coupler) Blend Appearance & Stability
Appearance / layer Zero day, °C After 6 months, °C
1 75:15:8-11 Clear single layer Stable at 15°C Stable at 15°C
2 82:10: 6-8 Clear blend Stable at 15°C Stable at 15°C
3 74-78:15:8-11 Clear blend Stable at 15°C Stable at 15°C
4 75:15:12 Clear blend Stable at 15°C Stable at 15°C
5 94:5:0.25-1 Clear blend Stable at 8°C Stable at 8°C
6 88.5:10:1.5 Clear blend Stable at 8°C Stable at 8°C
7 86:12:2-3 Clear blend Stable at 8°C Stable at 8°C
ULSD: BD: MeOH/EtOH: Coupler
8 73:7: 15:5-10 Clear blend Stable up to 10°C Stable up to 10°C
9 87:7: 5:0.25-5 Clear blend Stable up to 8°C Stable up to 8°C

All of the above compositions had a single phase demonstrating the efficacy of the use of above coupler to blend hydrocarbon fuels with alcohol/alkanol (C1-C4). These compositions were tested at varying temperatures which reflect typical operating temperatures for normal transport fuels and were not found to be temperature sensitive. ,CLAIMS:1. An additive composition for solubilizing lower alcohols in diesel fuel, comprising:
(i) 60 to 90% w/w of aliphatic alcohol with (C4-C20),
(ii) 0.5 to 5% w/w of fatty acid based lubricity improver with (C14 - C20); and
(iii) 0.5 to 5% w/w of polyetheramine based polydispersant with (C12 - C24),
wherein the diesel fuel is an ultra-low sulphur diesel fuel and wherein the lubricity improver is selected from Ester based lubricity improver compatible with diesel.

2. The composition as claimed in claim 1, wherein the polydispersant has molecular weight in a range of 800 to 1200 and wherein the molecular weight is preferably 1000.

3. The composition as claimed in claim 1, wherein the composition optionally comprises a cetane improver selected from a group consisting of 2-ethyl hexyl nitrate, H2O2 based cetane improver or a combination thereof.

4. The composition as claimed in claim 1, wherein the composition optionally comprises a corrosion inhibitor compatible with alcohol-diesel blends.

5. A method of producing the additive composition as defined in claim 1, comprising:
i. blending of alcohols (C4 - C20) preferably C8 - C12 in specific ratios at ambient temperature in a range of 25 to 35 °C with stirring; and
ii. adding fatty acid based lubricity improver to the blend of alcohols; and
iii. adding polymeric dispersant preferably polyetheramine (polyEA) having ~1000 MW with C12 - C24 to the mixture of alcohols and fatty acid with continuous stirring.

6. The method as claimed in claim 5, wherein the method comprises optionally adding a cetane improver and a corrosion inhibitor to the additive composition.

7. The method as claimed in claim 6, wherein the cetane improver is selected from a group consisting of 2-ethyl hexyl nitrate, H2O2 based cetane improver or a combination thereof.

8. The method as claimed in claim 6, wherein the corrosion inhibitor is compatible with alcohol - diesel blends.

9. A fuel blend comprising diesel fuel, aliphatic alcohols (C4 - C16), and additive composition, wherein the fuel blend comprises:
i. 60 to 90% v/v of the diesel fuel;
ii. 5 to 40% v/v of the alcohol (C1 - C4); and
iii. up to 40% v/v of the additive composition.

10. The fuel blend as claimed in claim 9, wherein the ratio of diesel fuel: alcohol: additive composition is 74-94: 5-20:0.25-12 and wherein the fuel blend comprises Biodiesel and the ratio of diesel fuel: biodiesel: alcohol: additive composition is 73-87:7:5-15:0.25-10.

11. The fuel blend as claimed in claim 9, wherein the coupler when present in a range of 0.1 to 20% v/v improves the solubility and dispersibilty of lower alcohols by up to 50%, v/v,