FORM-2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
PROVISIONAL
Specification
(See section 10 and rule 13)
METHOD FOR ENHANCING COLD FLOW PROPERTIES OF BIODIESEL
DAI-ICHI KARKARIA LIMITED
an Indian Company
of Mumbai-Pune Road, Kasarwadi, Pune 411 034,
Maharashtra, India,
THE FOLLOWING SPEC IFICATION DESCRIBES THE INVENTION.

Field of the invention:
The present invention relates to method for enhancing cold flow properties of biodiesel.
Background of the invention and prior art
Biodiesel is an alternative fuel formulated for diesel engines. It is typically made from vegetable oil or animal fats. Biodiesel can be used directly in any existing, unmodified diesel engine because it has similar properties to petroleum diesel fuel. Biodiesel can also be blended in any ratio with petroleum diesel fuel. Biodiesel can be mixed with petroleum diesel in any percentage, from 1 to 99, which is represented by a number following a B. For example, B5 is 5 percent biodiesel with 95 percent petroleum, B20 is 20 percent biodiesel with 80 percent petroleum, or B100 is 100 percent biodiesel and no petroleum.
Regular diesel fuel is winterized or seasonally adjusted at the distributor before it's delivered to the pumps. Winterizing diesel fuel is done to maintain the cold weather flow characteristics, and the ratios vary depending upon regional distribution. To effectively use biodiesel in cold climates, it must be mixed with winterized diesel in varying percentages, which, once again, are regionally dependent.
When using liquid hydrocarbons as lubricating oils or fuels, it is necessary that the hydrocarbon fluids flow readily at low temperatures, especially at temperatures below the freezing point of water (0.degree. C). the flow of these fluids, particularly those with high wax content, is very sensitive to low temperatures. At low temperature when the wax crystallizes, the fluid
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sets up as a waxy material and does not pour. The pour point depressant additives do not reduce the amount of wax which crystallizes from the fluids, but rather modify their surface by absorption or co-crystallization. This reduces the fluid occlusion by the crystals and changes the wax crystal structure, thus permitting the fluid to flow.
A more satisfactory easy solution is to use a suitable additive known as antigel or pour-point depressant. There's a range of antigel additives made for use with petroleum diesel, but they do not work very well with biodiesel. Some additives are specially formulated for use with biodiesel.
The pour point of a liquid is the lowest temperature at which it will pour or flow under prescribed conditions. It is a rough indication of the lowest temperature at which an oil is readily pumpable. This property is crucial for oils that must flow at low temperatures. Various polymeric compounds, popularly known as pour point depressants are used for lowering the pour point of different oils.
Poly(meth)acrylic esters of long chain alcohols (PAMA additives) are particularly considered to be highly effective in this regard. Major types of materials that have found wide acceptance as pour point depressants are naphthylene alkylated with chlorinated waxes, homo- or copolymers of hydrocarbon olefins, methacrylates, vinyl esters, alkyl styrene, fatty acid ester of isopropanol, 2-butanol, t-butanol or mixtures thereof, fatty acid ester such as oleate and linoleate esters.
Biodiesel is also blended with alkyl ester of C6- C\% saturated or unsaturated fatty acids, or mixture thereof, wherein the alkyl ester is methyl, ethyl,
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isopropyl, n-butyl or isobutyl ester or a mixture thereof. Some of the soluble polyalkylmethacrylates reduce the pour point. Some of the pour point depressants used in combustion oils, gear oils and like are carboxy containing interpolymers in which many of the carboxy groups are esterified and remaining carboxy groups, if any are neutralized by reaction with amino compounds, acrylate polymers, nitrogen containing acrylate polymers and methylene linked aromatic compounds.
Patent numbers US5338471 and US5338471 disclose a composition of at least one vegetable or synthetic triglyceride, esters from the transesterification of animal or vegetable oil triglyceride, a pour point depressant, and a performance additive. The composition of the pour point depressant is a mixed ester characterized by low-temperature modifying properties of an ester of a carboxy-containing interpolymer, being derived from at least two monomers, one of said monomers being a low molecular weight aliphatic olefin, styrene or a substituted styrene wherein the substituent is a hydrocarbyl group containing up to about 18 carbon atoms, and the other of said monomers being an alpha, beta-unsaturated aliphatic acid, anhydride or ester thereof.
Patent application number US20060236598 discloses a composition and method for improving cold weather performance of biodiesel fuels in cold climates, or at low temperatures. Such biodiesel can be used in low temperature without forming a precipitate and thus providing good filterability. Certain embodiments include the addition of chemical agents that prevent or inhibit precipitation of a water rich phase at low temperatures. Such agents include glycol ethers such as methylene glycol
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ethers such as the mono methyl ether of diethylene glycol, or ethylene glycol ethers, and also include alcohols, preferably lower alcohols such as methanol, ethanol or propane.
Pour point depressants disclosed above do not reduce pour point uniformly and are expensive. Most of the depressants are not suitable for biodiesel.
Hence there is a need for an efficient pour point depressant that works uniformly for biodiesels and reduces the pour point temperature significantly at low cost.
Objects of the invention:
One of the objects of the present invention is to provide a method for enhancing the cold flow properties of the biodiesel.
Another objective of the present invention is to provide a method of preparation of pour point depressant which is economical.
Yet another objective of the invention is to provide a pour point depressant composition which is Cost effective.
Yet another objective of the invention is to provide a pour point depressant composition which reduces the pour point temperature significantly.
Yet another objective of the present invention is to provide a pour point depressant composition which reduces the pour point temperature uniformly.

Summary of the invention:
Accordance with the present invention pour point depressant composition obtained by polymerizing metha crylic acid ester with an alcohol blend, wherein the alcohol blend comprises at least three alcohol selected from C10 fatty alcohol in the range of 5-15%, C12 fatty alcohol in the range of 30-60%, C14 fatty alcohol in the range of 10-20%, C16 fatty alcohol in the range of 10-20%), C18 fatty alcohol in the range 15-30%).
The pour point depressant composition in accordance with this invention is obtained by a process comprising
1. esterification of the alcohol blend in the presence of a catalyst solvent at a temperature of 80 - 150°C;
2. refluxing the reaction mixture obtain from step 1 at a temperature of 100 -120 °C and azeotropically removing water from the reaction mixture at a temperature of 100 -150 °C to obtain a ester;
3. washing of the ester obtained in step 2 with an alkali solution and dehydrating said ester by heating under vacuum filter;
4. polymerization of the ester formed in step 3 in the presence of a catalyst in a solvent at a temperature of 80-125 °C;
5. controlling of the reaction of step 4 by external cooling and adding more catalyst;
6. reapeating the above step 5 for l-2hrs and distillation of the solvent from the product obtained at a temperature of 120-150 °C at atmospheric pressure, followed by removal of the trace solvent by vacuum distillation; and
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7. dilution of product obtained in step 6 with mineral oil, synthetic fluid, methylester and the like, wherein the product is converted into 40% - 60% solid content.
Typically, the solvent used in step 1 is toluene.
Typically, the catalyst used in step 1 is p-toulene sulfonic acid.
Typically, the solvent used in step 3 are sodium hydroxide, potassium hydroxide, magnesium hydroxide, calcium hydroxide and the like Preferably, the solvent used is sodium hydroxide.
Typically, the solvent used in step 4 is toluene.
Typically, the catalyst used in step 4 is benzoly peroxide.
Typically, the esterification is carried out in a three/four neck flask equipped with heating arrangement, azeotropic distillation assembly, internal thermometer arrangement and mechanical stirrer.
Typically, the polymerization is carried out in a three/four neck flask equipped with heating arrangement, stirrer, reflux condenser, internal thermometer and a nitrogen inlet/outlet.
Typically, the distillation of polymerized product is carried out at atmospheric pressure.
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Typically, vacuum is applied to remove last traces of solvent.
Detailed description of the invention:
In accordance with the present invention there is provided a process for preparation of pour point depressant comprises the following steps:
Step 1: esterification
An alcohol blend comprising at least three alcohols, CIO fatty alcohol in the range of 5-15%, C12 fatty alcohol in the range of 30-60%, C14 fatty alcohol in the range of 10-20%, C16 fatty alcohol in the range of 10-20%, CI8 fatty alcohol in the range 15-30% is charged into a three necked flask equipped with heating arrangement, azeotropic distillation assembly and internal thermometer arrangement, to this toluene is added. This mixture is heated to 50 - 60°C. p - Toulene sulfonic acid and methacrylic acid is charged into the mixture and heating is continued at 60 ° C. The reaction mixture is refluxed at 100 - 110°C and the water of reaction being collected azeotropically. The reaction is continued for 6 hrs. up to a temperature of 120 - 125°C
The ester thus prepared is allowed to cool to 65 - 70°C, washed with water followed by wash with an alkali solution. Finally the ester is dehydrated by heating under vacuums filtered to obtain ester.
Step 2: polymerization
540 - 545 grams of said ester (from stage 1 above) and 200-215 grams of toluene is heated to 80°C in a three/four necked flask equipped with heating arrangement, stirrer, reflux condenser, internal thermometer is placed. 0.5 -
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0.9 grams of benzoyl peroxide is added to the reaction mixture at 70°C -80°C and the mixture is heated upto 98 - 100°C. Heating is stopped at 95°C -98°C and temperature is allowed to reach up to l00°C - 105°C by exothermicity of the reaction. The reaction is controlled below 105°C by external cooling arrangement if necessary to control the exotherm. The temperature is maintained at 100 - 102 for 1 - 2 hrs. After the exotherm is over 0.3 grams of benzoyl peroxide is added and the reaction continued at 100 - 102 for 1 hrs. This step is repeated once again for 1 hr which after the product is taken for distillation.
730-735 grams of polymerized product (of stage 2 above) is distillated to a maximum temperature of 130 - 140°C at atmospheric pressure followed by vacuum distillation to remove 395 parts of the solvent.
The above product is diluted with various optional oils, like mineral oil (paraffinic, naphthenic, aromatic), any synthetic fluids and/or methyl esters of the oils to convert the product to 50 +/- 10 % active content.
Example details:
Pour point depressant 1 was prepared using the following alcohol blend as given in table 1 and the process as detailed here in above. This pour point depressant is designated as PPD 1.
Similarly, Pour point depressant 2 was prepared using the following alcohol blend as given in table 1 and the process as detailed here in above. This pour point depressant is designated as PPD 2.
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Similarly, Pour point depressant 3 was prepared using the following alcohol blend as given in table 1 and the process as detailed here in above. This pour point depressant is designated as PPD 3.
Table 1: compositions of PPD 1, PPD 2 and PPD 3

Fatty alcohol PPD 1 PPD 2 PPD 3
CIO 11 - -
C12 38 45 35
C14 16 15 20
C16 13 15 25
C18 22 25 20
Experimentation:
PPD 1, PPD 2 and PPD 3 prepared as above were separately added to high diesel HSD, Soya based methyl ester (SME), palm based methyl ester (PME), lube oil - 100 (LUB 100), lube oil - 150 (LUB 150) and lube oil -500 (LUB 500)
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Table 2: Effect of polymeric additive on Diesel (HSD)

Additive Additive concentration in (%wt/wt) Pour point (°C) (ASTM D 97)
NONE Only HSD 3
PPD1 0.5 1.0 -6 -9
PPD2 0.5 1.0 -9-12
PPD3 0.5 1.0 -9-12
Table 3: Effect of polymeric additive on Soya based methyl ester (SME)

Additive Additive concentration in (%wt/wt) Pour Point (°C) (ASTM D 97)
NONE Only SME 0
PPD1 0.5 1.0 -9 -9
PPD2 0.5 1.0 -9-12
PPD3 0.5 1.0 -9-12
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Table 4: Effect of polymeric additive on Palm based methyl ester (PME)

Additive Additive concentration in(%wt/wt) Pour point (oC) (ASTM D 97)
NONE Only PME 12
PPD1 0.5 1.0 6 6
PPD2 0.5 1.0 63
PPD3 0.5 1.0 63
Table 5: Effect of polymeric additive on Lube Oil -100 (LUB 100)

Additive Additive concentration in (%wt/wt) Pour point (°C) (ASTM D 97)
NONE Only LUB 100 -9
PPD1 0.1 0.2 0.3 0.4 -21 -24-27-30
PPD2 0 1 0.20.30.4 -18-21-24 -24
PPD3 0 1 0.20.30.4 -18-27 -27 -30
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Table 6: Effect of polymeric additive on Lube Oil -150 (LUB 150)

Additive Additive concentration in (% wt/wt) Pour point (°C) (ASTM D 97)
NONE Only LUB 150 -9
PPD1 0 10.2 0.3 0.4 -^0-33 -33 -33
PPD2 0.1 0.20.30.4 -30-33-33 -33
PPD3 0.1 0.20.30.4 -33 -33-33-33
Table 7: Effect of polymeric additive on Lube Oil - 500 (LUB 500)

Additive Additive concentration in (% wt/wt) Pour point (°C) (ASTM D 97)
NONE Only LUB 500 -3
PPD1 0.1 0.2 0.3 0.4 -15 -18-18-21
PPD2 0.1 0.20.30.4 -12 -15 -18 -21
PPD3 0 1 0.20.30.4 -1S -18-18-21
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While considerable emphasis has been placed herein on the particular features of the preferred embodiment and the improvisation with regards to it, it will be appreciated the various modifications can be made in the preferred embodiments without departing from the principles of the invention. These and the other modifications in the nature of the invention will be apparent to those skilled in art from disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to interpreted merely as illustrative of the invention and not as a limitation.
Dated this 18th day of June, 2007

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