WO2009047786A2

WO2009047786A2 - A pour point depressant polymer composition

Info

Publication number: WO2009047786A2
Application number: PCT/IN2008/000377
Authority: WO
Inventors: Digmbar Abasaheb Jawak; Pradyot Mitra; Sasidharan Kesavan Kariparambil
Original assignee: Dai-Ichi Karkaria Limited
Priority date: 2007-06-18
Filing date: 2008-06-17
Publication date: 2009-04-16
Also published as: WO2009047786A3

Abstract

A pour point depressant polymer composition comprises a polymerised ester. The polymerized ester consists of (a) methacrylic acid; and (b) an alcohol blend. The alcohol blend comprises alcohols selected from a group of alcohols consisting of (i) at least one alcohol selected from C10 linear alcohol in the range of 0 - 15 %; (ii) at least one alcohol selected from C12-C14 linear alcohols with 1% hydrocarbon in the range of 40 - 70 % of the total mass of the blend; (iii) at least one alcohol selected from C12-C14 linear alcohols with 6% hydrocarbon is in the range of 30 - 60% of the total mass of the blend; and (iv) at least one alcohol selected from C16-C18 linear alcohols in the range of 3 - 20% of the total mass of the blend and a process for the preparation of the same.

Description

A POUR POINT DEPRESSANT POLYMER COMPOSITION

Field of invention:

The present invention relates to a method for enhancing cold flow properties ofbiodiesel.

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 as it has similar properties to petroleum diesel fuel. It can be blended in any ratio with petroleum diesel fuel. Biodiesel can be mixed with petroleum diesel in any percentage, from 1 to 99. This percentage is represented by a number followed by B. For example, B5 is 5 percent biodiesel with 95 percent petroleum, B20 is 20 percent biodiesel with 80 percent petroleum, or BlOO is 100 percent biodiesel and no petroleum.

Regular diesel fuel is winterized or seasonally adjusted at the refinery before it is delivered to the distributor. 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 depending on the regional weather conditions.

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 sets up as a waxy material and does not pour. 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 oil is readily pumpable.

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. To improve the flow, liquid hydrocarbons are mixed with a suitable additive known as antigel or pour-point depressant. There are ranges of antigel additives available for use with petroleum diesel, but they do not work very well with biodiesel. Some additives are specially formulated for use with biodiesel. Various polymeric compounds, popularly known as pour point depressants are used for lowering the pour point of different oils.

Polymethacrylic esters of long chain alcohols (PAMA additives) are particularly considered to be highly effective as an additive for biodiesel. Preferred compostions that have found wide acceptance as pour point depressants are naphthalene 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 Ce- Qs saturated or unsaturated fatty acids or mixtures of these fatty acids. The alkyl esters used are methyl, ethyl, isopropyl, n-butyl or isobutyl ester or a mixtures of these esters. 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. The carboxy groups are esterified and non esterified carboxy groups, if any are neutralized by reaction with amino compounds, acrylate polymers, nitrogen containing acrylate polymers and methylene linked aromatic compounds.

US patents 5338471 and 5413725 disclose composition of vegetable or synthetic triglyceride, esters from the trans-esterification 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. A low-temperature modifying properties of the ester of a carboxy-containing interpolymer is derived from at least two monomers. The monomers are a low molecular weight aliphatic olefin and styrene or a substituted styrene wherein the substituent is a hydrocarbyl group containing up to about 18 carbon atoms.

US patent application 20060236598 discloses a composition and method for improving cold weather performance of biodiesel fuels in cold climates, or at low temperatures. The composition includes chemical agents that prevent or inhibit precipitation of a water rich phase at low temperatures. Such agents include glycol ethers like methylene glycol 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 biodiesel.

Another objective of the present invention is to provide a method of preparation of a 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 of a substance significantly.

Yet another objective of the present invention is to provide a pour point depressant composition which reduces the pour point temperature of a substance uniformly. Summary of the invention:

In accordance with this invention there is provided a pour point depressant polymer composition comprising a polymerised ester of

methacrylic acid; and

an alcohol blend, wherein the alcohol blend comprises alcohols selected from a group of alcohols consisting of at least one alcohol selected from C i₀ linear alcohol; at least one alcohol selected from Ci₂ - Ci₄ linear alcohols with 1% hydrocarbon; at least one alcohol selected from C ₁₂ - C ₁₄ linear alcohols with 6% hydrocarbon; and at least one alcohol selected from Q₆ - Ci₈ linear alcohols.

Typically, C ₁₀ linear alcohol in the range of 0 - 15 %, the Ci₂ - Cj₄ linear alcohol with 1% hydrocarbon is in the range of 40 - 70 % of the total mass of the blend, the Ci₂ - Ci₄ linear alcohol with 6% hydrocarbon is in the range of 30 - 60% of the total mass of the blend and C]₆ - Ci₈ linear alcohol is in the range of 3 - 20% of the total mass of the blend.

Typically, the molar ratio of alcohol: methacrylic acid is in the range of 1 :1 to l : 1.1.

Typically, the ester includes at least one catalyst (I), at least one solvent (I) and at least two inhibitor. Typically, the catalyst (I) is selected from a group of catalysts consisting of of p-toulene sulfonic acid, methane sulfonic acid and sulfuric acid.

Typically, the inhibitor is selected from a group of inhibitors consisting of hydroquinone, methoxyhydroquinone, phenothiazine, copper chloride, copper acetate, copper fillings and methylene blue.

Typically, the solvent (I) is selected from a group of solvents consisting of toluene, benzene, xylene, ethyl benzene and hexane.

Typically, the polymer of the ester includes at least one solvent (II) and at least one catalyst (II).

Typically, the solvent (II) is selected from the group of solvents consisting of toluene, benzene, xylene, mixed xylene and ethyl benzene.

Typically, the catalyst (II) is selected from the group of catalysts consisting of benzoyl peroxide, di-tertiary butyl peroxide and Azobisisobutyronitrile.

Typically, the composition is in the form of a yellow to brown transparent viscous liquid with a viscosity of 75 cps to 200 cps at 30 degree C.

In accordance with this invention there is also provided a process for the preparation of a pour point depressant composition as claimed in claim 1, comprising

blending of the following alcohols; at least one alcohol selected from C i₀ linear alcohol in the range of 0 - 15 %;

at least one alcohol selected from C_I2 - C_H linear alcohol with 1% hydrocarbon in the range of 40 - 70% of the total mass of the blend;

at least one alcohol selected from Ci₂ - Ci₄ linear alcohol with 6% hydrocarbon in the range of 30 - 60% of the total mass of the blend; and

at least one alcohol selected from Ci₆ - C is linear alcohol in the range of 3 - 20% of the total mass of the blend.

adding methacrylic acid to the alcohol blend to form a mixture;

esterifying the mixture in the presence of a catalyst (I), at least two inhibitors and a solvent (I) at a temperature of 80 - 150⁰C to form a resultant mixture;

refluxing the resultant mixture at a temperature of 100 -120⁰C and removing water therefrom to obtain an ester;

polymerizing the ester in the presence of a catalyst (II) and a solvent (II) at a temperature of 80 - 125 ⁰C and distilling off the solvent from the polymer to obtain the pour point depressant composition. Typically the process includes the step of washing of the ester with an alkali solution.

Typically the process includes the step of dehydrating the ester by heating under vacuum.

Alternatively or in addition the process includes the step of azeotropically dehydrating the ester at a temperature of 100 - 150° C

Preferably, the process includes the step of adding of catalyst (II) in 3 stages, wherein a first portion of the catalyst (II) is added at the start of the polymerization reaction, a second portion is added when the reaction temperature is 90 - 100⁰C and a third portion of the catalyst (II) is added when the reaction temperature is 95 - 100⁰C.

Typically, the polymerization is allowed to proceed for 6 - 12 hours.

Preferably, the mass of ester to catalyst (II) is in the ratio of 1 : 0.003 to 1 : 0.010.

Preferably, the distillation step is done in two stages, wherein first stage involves distilling off the solvent (II) at atmospheric pressure and at 120 - 150° C temperature and second stage involves vacuum distilling of traces of solvent (II).

Typically, the process includes the step of diluting the polymer with a diluent. Typically, the mass of polymer to mass of diluent is 1 : 0.66 to 1 :1.5.

Typically, the diluent is selected from mineral oil and coco methyl ester.

Typically, the polymerization temperature is controlled by external cooling.

Preferably, the esterification is carried out in a three/four neck flask equipped with a heating arrangement, azeotropic distillation assembly, internal thermometer arrangement and mechanical stirrer.

Preferably, the polymerization is carried out in a three/four neck flask equipped with a heating arrangement, stirrer, reflux condenser, internal thermometer and a nitrogen/air inlet/outlet.

Detailed description of the invention:

The present invention provides an improvement in conventional method of blending biodiesel with an anti gel or a pour point depressant in cold conditions wherein the pour point depressant overcomes the problems mentioned in the prior art. Generally to improve the flow properties, liquid hydrocarbons are mixed with a suitable additive such as antigel or pour- point depressant. The pour point depressant additives do not reduce the amount of wax which crystallizes the fluids, however it modifies the surface of the fluids by absorption or co-crystallization. This reduces the fluid occlusion by the crystals and changes the wax crystal structure and permits the fluid to flow. In a preferred embodiment, a polymerized ester is prepared to enhancing cold flow properties of biodiesel, wherein the pour point depressant is added to the biodiesel, or to the mixture of diesel and biodiesel that prevent the flow of the fluid in cold conditions.

The pour point depressant polymer composition according to this invention comprises a polymerised ester. The polymerized ester consists of (a) methacrylic acid; and (b) an alcohol blend. The alcohol blend comprises alcohols selected from a group of alcohols consisting of (i) at least one alcohol selected from C ₁₀ linear alcohol in the range of 0 - 15 % (ii) at least one alcohol selected from C 12 - C 14 linear alcohols with 1% hydrocarbon in the range of 40 - 70 % of the total mass of the blend; (iii) at least one alcohol selected from C 12 - C 14 linear alcohols with 6% hydrocarbon is in the range of 30 - 60% of the total mass of the blend; and (iv) at least one alcohol selected from Cl 6 - Cl 8 linear alcohols in the range of 3 - 20% of the total mass of the blend;

In another preferred embodiment, there is provided a process for the preparation of pour point depressant polymer. The process comprises the following steps

Step 1 : esterification

The above said alcohol blend along with a catalyst (I) preferably p-toluene sulfonic acid, at least two inhibitor preferably, hydroquinone and phenothiazine and a solvent preferably toluene is charged into a four neck round bottom flask to form a mixture. The flask is provided with a compressed air inlet, a stirrer and a thermometer. The mixture is heated slowly to 9O⁰C with stirring. Methacrylic acid in toluene is added in the flask within 15 minutes to form a resultant mixture. Typically, the molar ratio of alcohol: methacrylic acid is in the range of 1 : 1 to 1 : 1.1. After the addition of the solvent is completed, air is allowed to purge into the resultant mixture. The resultant mixture is heated up to 105⁰C to form a crude ester. Water from the crude ester is distilled off by azeotropic distillation to separate crude ester containing less than 2 % unreacted alcohol and an acid value of less than 10. The crude ester is cooled to 35°C. The crude ester, is caustic washed by adding an alkali solution preferably, 4% sodium hydroxide solution under mixing. This mixture is stirred for 15 min and allowed to settle at 35⁰C for 1 hour. The lower aqueous layer is separated and the upper ester layer is washed with water at 35 degree C with stirring for 5 minutes and allowing it to settle for 3 hours. Water is separated as lower layer and the ester solution is filtered off. A clear transparent ester with less than 0.2% water is obtained.

Step 2: Polymerization

The ester from step 1 and a solvent preferably, toluene is charged into a reaction vessel provided with a thermometer, a reflux condenser, a stirrer and a cooling arrangement to control the exothermic reaction and to maintain the temperature between 92 - 100⁰C. The mixture is heated to 92⁰C. A catalyst (II) preferably, benzoyl peroxide is added to the mixture. The temperature of reaction is maintained at 95 - 97 degree C for 3 hours to form a viscous reaction mass. If necessary the exothermicity of the reaction is controlled by external cooling arrangement. Further, a second portion of benzoyl peroxide is added to the reaction mass and a temperature of 95 - 100⁰C is maintained for 2 hours. A third and final portion of benzoyl peroxide is added to the reaction mass and the reaction is continued for 1 hour at 95°C. Finally, the temperature of the reaction mass is increased to 100 - 102⁰C and is maintained for 30 minutes. A polymerized product is obtained. Viscosity of the product is measured to be 175 cPs at 30⁰C in toluene.

The polymer thus obtained is taken in a reaction vessel provided with distillation assembly. Typically, the distillation step is done in two stages, wherein first stage involves distilling off the solvent (II) at atmospheric pressure and at 120 - 150° C temperature and second stage involves vacuum distilling of traces of solvent (II). After the distillation process is completed, Optionally, a dilutent preferably coco methyl ester is added for diluting the polymer. The above product can also be diluted with various oils like mineral oil, paraffmic naphthenic aromatic, synthetic fluids and methyl esters to convert the product to 50 +/- 10 % polymer content. Typically, the mass of polymer to mass of dilutent is 1: 0.66 to 1:1.5. The mixture is stirred and cooled. A yellow to brown transparent viscous liquid pour point depressant composition is obtained.

Typically, the catalyst (I) is selected from a group of catalyst consisting of p- toulene sulfonic acid, methane sulfonic acid and sulfuric acid.

Typically, the solvent (I) is selected from a group of solvents consisting of toluene, benzene, xylene, ethyl benzene and hexane. Typically, the solvent (II) is selected from the group of solvents consisting of toluene, benzene, xylene, mixed xylene and ethyl benzene.

Pour point depressants were prepared by the process as described above and added separately to high speed diesel (HSDO, 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). The 3 pour point depressants prepared are represented as PPD 1, PPD 2 and PPD 3. The effect of the pour point depressant composition prepared in accordance with this invention is as shown in the tables (table 1 to table 6) below.

The pour point depressant (PPD) composition obtained in accordance with this invention reduces the pour point temperature of a substance significantly. Some additives are specially formulated for blending with biodiesel. In blending the pour point depressant with biodiesel the uniform distribution of these depressant is important, hence the PPD composition obtained in accordance to this invention is suitable for blending of various kinds of biodiesel with uniform distribution of the additive thereby improving the flow properties of the biodiesel. The pour point of the various biodiesel, diesel and lube oils are reduced significantly and ranges from -9 to -33⁰C. The invention will now be described with respect to the following examples which do not limit the invention in any way and only exemplify the invention.

Example 1 :

The experiment was carried out in two steps

Step 1 : Esterification

198 gms of Ci₂ - Cu linear alcohol containing 1% hydrocarbon, 198 gms of Ci₂ - Cu linear alcohol containing 6% hydrocarbon, 264 gms of Ci₆ - Cis linear alcohol, 12.5 gms of p-toluene sulfonic acid, 5 gms of phosphorous acid, 1.2 parts of hydroquinone, 0.34 gms of methoxy hydroquinone, 0.068 gms of phenothiazine A and 680 gms of Toluene was charged into a four neck round bottom flask to form a reaction mixture. The flask is equipped with compressed air inlet, stirrer, thermometer, Dean and Stark assembly. The reaction mixture was heated slowly with stirring to 9O⁰C. Further, 264 gms of methacrylic acid in 130 gms of toluene was added to the reaction mixture in the flask within 15 minutes to form resultant mixture. To this resultant mixture air was purged and was heated up to 105⁰C. 59 gms of water was distilled out by azeotropic distillation and 1685 gms of the crude ester was separated out containing less than 2 % unreacted alcohol and acid value less than 10.

1685 gms of the crude ester obtained was warmed to 35°C and 189.5 gms of 4% sodium hydroxide solution was added to the ester under mixing. The mass was mixed for 15 minutes and allowed to settle at 35°C for 1 hour. The lower aqueous layer was separated and 1660 gms of the crude ester was . obtained. The crude ester was caustic washed and 337 gms of water at 35⁰C was added and stirred for 5 minutes and allowed to settle for 3 hours. Water was separated as lower layer. The ester solution thus obtained was filtered and 1609 gms of clear transparent ester (IE) was obtained containing less than 0.2% water.

Step 2: Polymerization

545 gms of the ester from step 1 and 121 gms of toluene was charged into a reaction vessel equipped with thermometer, reflux condenser, a stirrer and a provision for cooling to control the exotherm and to maintain the temperature between 92 - 100⁰C. The mixture was heated to 92°C and 0.9 gms of benzoyl peroxide was added. The temperature of reaction was maintained at 95 (maximum) for 3 hours to form a reaction mass. Further, 0.6 gms of benzoyl peroxide was added to the reaction mass and a temperature of 95⁰C was maintained for 2 hours. A third and final lot of 0.1 gms of benzoyl peroxide was added to the reaction mass and the reaction was continued for 1 hour at 95⁰C. Finally, the temperature of the reaction mass was increased to 100⁰C and was maintained for 30 minutes. 665 gms of the polymerized product (IP) was obtained. The Brookfield viscosity of the product was measured to be 175 cPs at 30⁰C in Toluene at 40% concentration.

The polymer (IP) thus obtained was taken in a reaction vessel provided with distillation assembly. Initially toluene was distilled at atmospheric pressure at 14O⁰C followed by vacuum distillation. 330 gms of toluene was distilled off. 294 gms of Coco methyl ester was added to the reactor for dilution. The mixture was stirred and cooled. 590 gms of the polymer (IP) was obtained as yellow to brown colored transparent viscous liquid.

Example 2

Example 2 was carried out as per example 1 wherein the blend of alcohol used was 370 gms of C₁₂ - C₁₄ linear alcohol containing 1% hydrocarbon and 290 gms of Ci₆- Cig linear alcohol. Ester (2E) obtained from example 2 was polymerized as per step 2 in example 1 with a viscosity of 150 cps at 30⁰C. A light brown viscous liquid Polymer (2P) was obtained using coco methyl ester as a diluent.

Example 3

Example 3 was carried out as per example 1 wherein the blend of alcohol used was 354gms of C1₂ - C_H linear alcohol containing 1% hydrocarbon, 193 gms of Ci₆ - Cig linear alcohol, 55 gms of linear Cigalcohol and 60 gms of linear C ₁₀ alcohol. Ester (3E) obtained from example 3 was polymerized as per step 2 of example 1 with a viscosity of 130 cps at 30⁰C. A light brownish yellow viscous liquid polymer (3P) was obtained using coco methyl ester as a diluent.

Example 4

Example 4 was carried out as per example 1 wherein the blend of alcohol used was 354 gms of Ci₂ - Ci₄ linear alcohol containing 1% hydrocarbon, 193 gms Of Ci₆- Ci₈ linear alcohol, 55 gms of C^ linear alcohol and 60 gms of Cio linear alcohol and 3.5 gms copper acetate was used as inhibitor. Crude ester obtained was processed by allowing copper acetate to settle down for 1 hour and then was removed. Crude ester was washed with water followed by neutralization with 25% NaOH and filtered. Ester (4E) obtained of example 4 was polymerized as per step 2 of example 1 with viscosity of 120 cps at 30⁰C. A light yellow viscous clear liquid polymer (4P) was obtained using coco methyl ester as a diluent.

Example 5

Example 5 was carried out as per example 1 to obtain ester (IE). (IE) was polymerized as per step 2 of example 1 and the polymer (IP) obtained was diluted with hydrocarbon oil, LUB 150 to obtain a yellow viscous transparent liquid polymer (5P).

Example 6

Example 6 was carried out as per example 1 to obtain ester (IE). The Brookfield viscosity of the polymer (6P) prepared is measured to be 120 cps at 30⁰C. This polymer was subjected to distillation of toluene and then diluted with coco methyl ester similar to example 1 to get light brownish yellow clear viscous liquid was obtained.

Example 7

Example 7 was carried out as per example 1 wherein in step 1 the solvent used was benzene. A light brown color viscous polymer was obtained.

Example 8

Example 8 was carried out as per example 1 wherein in step 1 the solvent used was xylene. A brownish yellow color viscous polymer was obtained. Esterification was carried out under vacuum. Example 9

Example 9 was carried out as per example 1 wherein in step 1 the solvent used was ethyl benzene. A brownish yellow color viscous polymer was obtained. Esterifϊcation was carried out under vacuum.

Example 10

Example 10 was carried out as per example 1 wherein in step 1 the solvent used was hexane. A light brown color viscous polymer was obtained.

Example 11

Example 11 was carried out as per example 1 wherein the esterifϊcation reaction was carried out without solvent, in this case water of the reaction was collected under vacuum.

Example 12

Example 12 was carried out as per example 4 wherein hydroquinone and methoxy hydroquinone were used as an inhibitor. A yellow viscous transparent liquid polymer was obtained.

Example 13

Example 13 was carried out as per example 4 wherein methoxyhydro quinone and phenothiazine were used as an inhibitor. A yellow viscous transparent liquid polymer was obtained. Example 14

Example 14 was carried out as per example 4 wherein Phenothiazine and hydroquinone were used as an inhibitor. A yellow viscous transparent liquid polymer was obtained.

Example 15

Example 15 was carried out as per example 4 wherein copper chloride and hydroquinone were used as an inhibitor. A yellow viscous transparent liquid polymer was obtained.

Example 16

Example 16 was carried out as per example 4 wherein copper fillings and hydroquinone were used as an inhibitor. A yellow viscous transparent liquid polymer was obtained.

Example 17

Example 17 was carried out as per example 4 wherein methylene blue and hydroquinone were used as an inhibitor. A yellow viscous transparent liquid polymer was obtained.

Example 18

Example 18 was carried out as per example 1, wherein the esteriflcation reaction was carried out at temperature of 95 - 105 degree C. Example 19

Example 19 was carried out as per example 1, wherein the esterification reaction was carried out at temperature of 100 - 115 degree C.

Example 20

Example 20 was carried out as per example 1, wherein the esterification reaction was carried out at temperature of 100 - 125 degree C.

Example 21

Example 21 was carried out as per example 1, wherein methane sulfonic acid was added as catalyst with stirring at 90⁰C in the esterification reaction.

Example 22

Example 22 was carried out as per example 1, wherein sulfuric acid was added as catalyst with stirring at 90⁰C in the esterification reaction.

Example 23

Example 23 was carried out as per example 1 , wherein polymerization was carried out using benzene as a solvent. A yellow viscous transparent liquid polymer was obtained.

Example 24

Example 24 was carried out as per example 1 , wherein polymerization was carried out using xylene as a solvent. A yellow viscous transparent liquid polymer was obtained. Example 25

Example 25 was carried out as per example 1, wherein polymerization was carried out using mixed xylene as a solvent. A yellow viscous transparent liquid polymer was obtained.

Example 26

Example 26 was carried out as per example 1 , wherein polymerization was carried out using ethyl benzene as a solvent. A yellow viscous transparent liquid polymer was obtained.

Example 27

Example 27 was carried out as per example 1 wherein, di - tertiary butyl peroxide was used as a catalyst in the polymerization reaction. A yellow viscous transparent liquid polymer was obtained.

Example 28

Example 28 was carried out as per example 1 wherein, Azobisisobutyronitrile (AIBN) was used as a catalyst in the polymerization reaction. A yellow viscous transparent liquid polymer was obtained.

Example 29

Example 29 was carried out as per example 1, wherein the polymerization temperature was carried out at 85 - 90 degree C. Example 30

Example 30 was carried out as per example 1, wherein the polymerization temperature was carried out at 90 - 95 degree C.

Example 31

Example 31 was carried out as per example 1, wherein the polymerization temperature was carried out at 105 - 110 degree C.

Pour point depressants were prepared separately as described above and added to high speed 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). The pour point depressants prepared are represented as PPD 1, PPD 2 and PPD 3.

Polymers of experiments 3 (3P) and 4 (4P) represent PPD 1, polymer of experiment 2 (2P) represents PPD 2, polymers of experiments 1, 5 and 6 (IP, 5P and 6P) represent PPD 3.

The effect of the polymers prepared as above on the depression of the pour point of the respective oils are tabulated below

Table 1 describes the depression of pour point of High Speed Diesel (HSD) using the polymers described Table 1: Effect of polymeric additive on Diesel (HSD)

Table 2 describes the depression of pour point of Soya based methyl ester (SME) using the polymers described above.

Table 2: Effect of polymeric additive on Soya based methyl ester (Soya based biodiesel) (SME)

Table 3 describes the depression of pour point of Palm based methyl ester (PME) using the polymers described above.

Table 3: Effect of polymeric additive on Palm based methyl esteV (Palm based biodiesel) (PME)

Table 4 describes the depression of pour point of Hydrocarbon oil (LUB 100) using the polymers described above.

Table 4: Effect of polymeric additive on Hydrocarbon oil (LUB 100)

Table 5 describes the depression of pour point of Hydrocarbon oil (LUB 150) using the polymers described above.

Table 5: Effect of polymeric additive on Hydrocarbon oil (LUB 150)

Table 6 describes the depression of pour point of Hydrocarbon oil (LUB 500) using the polymers described above.

Table 6: Effect of polymeric additive on Hydrocarbon oil (LUB 500)

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.

Claims

Claims:

1. A pour point depressant polymer composition comprising a polymerized ester of a. methacrylic acid; and b. an alcohol blend, wherein the alcohol blend comprises alcohols selected from a group of alcohols consisting of

I. at least one alcohol from C ₎₀ linear alcohol;

II. at least one alcohol selected from C₁₂ - C₁₄ linear alcohols with 1% hydrocarbon;

III. at least one alcohol selected from C₁₂ - C₁₄ linear alcohols with 6% hydrocarbon; and

IV. at least one alcohol selected from Ci₆ - Ci₈ linear alcohols.

2. A pour point depressant polymer composition as claimed in claim 1, wherein, the C ₁₀ linear alcohol in the range of 0 - 15 %, Cj₂ - Cj₄ linear alcohol with 1% hydrocarbon is in the range of 40 - 70 % of the total mass of the blend, the Cj₂ - Ci₄ linear alcohol with 6% hydrocarbon is in the range of 30 - 60% of the total mass of the blend and C₁₆ - Cj₈ linear alcohol is in the range of 3 - 20% of the total mass of the blend

3. A pour point depressant polymer composition as claimed in claim 1, wherein the molar ratio of alcohol: methacrylic acid is in the range of 1 :1 to 1: 1.1.

4. A pour point depressant polymer composition as claimed in claim 1, wherein the ester includes at least one catalyst (I), at least one solvent (I) and at least two inhibitors.

5. A pour point depressant polymer composition as claimed in claim 4, wherein, the catalyst (I) is selected from a group of catalysts consisting of of p-toulene sulfonic acid, methane sulfonic acid and sulfuric acid.

6. A pour point depressant polymer composition as claimed in claim 4, wherein, the inhibitor is selected from a group of inhibitors consisting of hydroquinone, methoxyhydroquinone, phenothiazine, copper chloride, copper acetate, copper fillings and methylene blue.

7. A pour point depressant polymer composition as claimed in claim 4, wherein, the solvent (I) is selected from a group of solvents consisting of toluene, benzene, xylene, ethyl benzene and hexane.

8. A pour point depressant polymer composition as claimed in claim 1, wherein the polymer of the ester includes at least one solvent (II) and at least one catalyst (II).

9. A pour point depressant polymer composition as claimed in claim 8, wherein, the solvent (II) is selected from the group of solvents consisting of toluene, benzene, xylene, mixed xylene and ethyl benzene.

10. A pour point depressant polymer composition as claimed in claim 8, wherein the catalyst (II) is selected from the group of catalysts consisting of benzoyl peroxide, di-tertiary butyl peroxide and Azobisisobutyronitrile.

11. A pour point depressant polymer composition as claimed in claim 1, wherein, the composition is in the form of a yellow to brown transparent viscous liquid.

12. A process for the preparation of a pour point depressant composition as claimed in claim 1 , comprising a) blending of the following alcohols;

I. at least one alcohol from C io linear alcohol in the range of 0 - 15

% II. at least one alcohol selected from Ci₂ - C_H linear alcohol with

1% hydrocarbon in the range of 40 - 0% of the total mass of the blend;

III. at least one alcohol selected from Ci₂ - C_]4 linear alcohol with 6% hydrocarbon in the range of 30 - 60% of the total mass of the blend; and

IV. at least one alcohol selected from Ci₆ - C₎₈ linear alcohol in the range of 3 - 20% of the total mass of the blend. b) adding methacrylic acid to the alcohol blend to form a mixture; c) esterifying the mixture in the presence of a catalyst (I), at least two inhibitors and a solvent (I) at a temperature of 80 - 150 ⁰C to form a resultant mixture; d) refluxing the resultant mixture at a temperature of 100 -120 ⁰C and removing water therefrom to obtain an ester; e) polymerizing the ester in the presence of a catalyst (II) and a solvent (II) at a temperature of 80 - 125 ⁰C and distilling off the solvent from the polymer to obtain the pour point depressant composition.

13. A process for the preparation of pour point depressant composition as claimed in claim 12, which includes the step of washing of the ester with an alkali solution.

14. A process for the preparation of pour point depressant composition as claimed in claim 12, which includes the step of dehydrating the ester by heating under vacuum.

15. A process for the preparation of pour point depressant composition as claimed in claim 12, which includes the step of azeotropically dehydrating the ester.

16. A process for the preparation of pour point depressant composition as claimed in claim 12, which includes the step of adding of catalyst (II) in 3 stages, wherein a first portion of the catalyst (II) is added at the start of the polymerization reaction, a second portion is added when the reaction temperature is 92⁰C and a third portion of the catalyst (II) is added when the reaction temperature is 95⁰C.

17. A process for the preparation of pour point depressant composition as claimed in claim 12, wherein in step e the polymerization is allowed to proceed for 6 - 12 hours.

18. A process for the preparation of pour point depressant composition as claimed in claim 15, wherein the mass of ester to catalyst (II) is in the ratio of 1 : 0.003 to 1 : 0.010.

19. A process for the preparation of a pour point depressant composition as claimed in claim 12, wherein the distillation step is done in two stages, wherein first stage involves distilling off the solvent (II) at atmospheric pressure and at 120 - 150° C temperature and second stage involves vacuum distilling of traces of solvent (II).

20. A process or the preparation of pour point depressant composition as claimed in claim 12, which includes the step of diluting the polymer with a diluent.

21. A process for the preparation of pour point depressant composition as claimed in claim 18, wherein the mass of polymer to mass of diluent is 1: 0.66 to 1 : 1.5.

22. A process for the preparation of pour point depressant composition as claimed in claim 18, wherein the dilutent is selected from mineral oil and coco methyl ester.

23. A process for the preparation of pour point depressant composition as claimed in claim 12, wherein the polymerization temperature is controlled by external cooling.

24. A process for the preparation of pour point depressant composition as claimed in claim 12, wherein the polymerization temperature is controlled by adding the catalyst (II).