FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
(See section 10, rule 13)
1. Title of the invention
A CATALYST FOR THE PRODUCTION OF FATTY ACID ALKYL ESTERS
2. Applicant(s)
Name Nationality Address
TATA CHEMICALS LTD. INDIA BOMBAY HOUSE, 24 HOM1 MODI STREET,
MUMBAI 400001
3. Preamble to the description
COMPLETE SPECIFICATION
The following specification particularly describes the invention and the manner in which it is
to be performed.

The present application has been divided out of co-pending patent application no,
1644/MUM/2009 dated July 14,2009.
The following disclosure generally relates to a catalyst for the production of fatty acid alkyl esters.
BACKGROUND
Bio-lubricants are essentially fatty acid alkyl esters, with the alkyl chain usually higher than a C5 unit. This finished product derived from renewable raw material such as animal fats and vegetable oils (lipids) is a bio-degradable and a non-toxic alternative to synthetic lubricants. Apart from its use in automobile industry, bio-lubricants are also used in the manufacture of cosmetics, feedstuffs, soaps etc.
Conversion of the lipids to bio-lubricant involves the initial reaction where ester linkages of the fatty acids with glycerol are broken to form corresponding fatty acids and glycerol. The free fatty acids are in the subsequent step converted into fatty acid alkyl (e.g., hexyl, heptyl, 2 ethylhexyl, octyl, decyl and their respective isomers) esters using alkanol (e.g., hexanol, heptanol, 2-ethylhexanol, octanol, decanol and their respective isomers) as the reactant. These reactions may also take place simultaneously. The total process is termed as transesterification and the final products of the reaction are bio-lubricant and glycerol. Such transesterification reaction can be catalyzed both by acids and bases.
Existing technology for transesterification processes use homogeneous alkali catalyst such as NaOH or KOH. While the homogeneity of the reaction mass enhances the conversion rate, the catalyst is part of the reaction product. This makes it necessary to carry out a complicated step of separation and/or removal of the catalyst. The process of

separating bio-lubricant from catalyst and glycerol involves a neutralization process with strong acids (e.g., Hcl), and extensive washes with water to remove the resulting sodium salt. Further, in order to remove sodium chloride from glycerol and to obtain glycerol in
high purity, distillation of high boiling glycerol has to be carried out which is an energy
intensive operation.
The use of alkali catalyst also cause saponification of free fatty acids contained in fats and oils to form, soaps as by products, whereby it becomes necessary to carry out a step of washing with large amounts of water. In addition, the yield of fatty acid alkyl esters (bio-lubricant) decreases due to the emulsification effect of the soaps generated and, in certain instances, the subsequent glycerine purification process also becomes complicated. In order to overcome the problem associated with free fatty acids, a strong homogeneous acid like sulphuric acid is generally used along with the reactant alcohol (e.g., methanol) as a pre-treatment catalyst that converts free fatty acids to alkyl esters. However, if acid is used in the pre-trea.tment process, neutralization of oil has to be done before trans-esterification reaction may De carried out. This further creates economical and environmental concerns.
In order to overcome the problems associated with use of a homogeneous catalyst, heterogenous solid Catalysts for the trans-esterification of oils to alkyl esters have been developed. For exarnple) various basic metal oxides, such as magnesium methoxide, calcium oxide, calcium alkoxide, and barium hydroxide, have been demonstrated to be active catalysts for trans- esterifi cation.
However, the recyclability of these solid base catalysts is poor. This is because of the moderate solubility of some of these solid metal oxides, hydroxides and alkoxides in methanol/ethanol anq strong physical adsorption of the reaction products on their surfaces.

Use of double metal cyanides and metal (e.g., Zn, Mo) embedded on supports (like alumina) as recyclable solid catalysts have also been claimed recently. The major drawback of such a catalyst is its relatively higher cost of preparation and therefore requiring large number of recycles. These recovery and further activation for recycling of catalyst cause technical and economic restrains.
In view of these drawbacks, there is a need to develop a process for production of fatty acid alkyl esters useful as bio-lubricants that does not require tedious aqueous washes and neutralization steps. An economical and recyclable catalyst that can be easily separated from the fatty acid alkyl ester products for the conversion of oils to bio-lubricants is also needed. Moreover, a catalyst that can economically catalyse both the esterification of free fatty acids and trans-esterification of oils to alkyl esters useful as bio-lubricants is desirable.
SUMMARY
The invention relates to a catalyst composite for the production of fatty acid alkyl esters having a C5 to C10 alkyl chain from a feedstock including one or more fatty acid glycerol esters or one or more fatty acids or a mixture thereof, wherein the catalyst composite comprises of a nano composite catalyst having a particle size in the range of 5 nm to 1000 nm and comprising of oxides, mixed oxides, silicates or sulphates of one or more of silica, alumina, calcium and iron.
The invention also relates to a catalyst composite for the production of fatty acid alkyl esters having a C5 to C10 alkyl chain from a feedstock including one or more fatty acid glycerol esters or one or more fatty acids or mixture thereof, wherein the catalyst composite comprises a catalyst composition comprising of oxides, mixed oxides, silicates

or sulphates of two or more of silica, aluminium, iron, calcium, magnesium, sodium and potassium.
The invention also relates to a catalyst composite for the production of fatty acid alkyl esters having a C5 to C10 alkyl chain from a feedstock including one or more fatty acid glycerol esters or one or more fatty acids or mixture thereof, the catalyst composite comprises, a catalyst composition comprising of oxides, mixed oxides, silicates or sulphates of two or more of silica, aluminium, iron, calcium, magnesium, sodium and potassium, and a nano composite catalyst having a particle size in the range of 5 nm to 1000 nm and comprising of oxides, mixed oxides, silicates or sulphates of one or more of silica, alumina, calcium and iron.
DETAILED DESCRIPTION
To promote an understanding of the principles of the invention, reference will be made to the embodiment and specific language will be used to describe the same. It will nevertheless be understood that no limitation of scope of the invention is thereby intended, such alterations and further modifications in the illustrated process and such further applications of the principles of the inventions as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates.
A catalyst for the production of fatty acid alkyl esters having C5 to C10 alkyl chain from a feedstock including one or more fatty acid glycerol esters or one or more fatty acids or mixture thereof is described. The catalyst comprises of a nano composite catalyst having a particle size in the range of 5 nm to 1000 nm and comprising oxides, mixed oxides, silicates or sulphates of one or more of silica, alumina, calcium and iron. The nano-composite catalyst may comprise of 25 to 75 weight percent tricalcium silicate (Ca3SiO5), 10 to 40 weight percent dicalcium silicate (Ca2SiO4), 1 to 20 weight percent tricalcium

Ruminate (Ca3Al2O6) and 1 to 20 weight percent tetracalcium aluminoferrite (Ca4Al2Fe2O10).
In accordance with an aspect, the catalyst is a composite including the nano composite catalyst. The catalyst composite may also contain any inert or active component. The amount of nano composite in the catalyst composite is at least 5 weight percent.
In accordance with an alternate embodiment, the catalyst is a catalyst composite, the catalyst composite comprising of a catalyst composition comprising of two or more of oxides, mixed oxides, silicates or sulphates of two or more of silica, aluminium, iron, calcium, magnesium, sodium and potassium.
The catalyst composition may comprise of 25 to 75 weight percent tricalcium silicate (Ca3SiO5), 10 to 40 weight percent dicalcium silicate (Ca2SiO4), 1 to 20 weight percent tricalcium aluminate (Ca3Al2O6) and 1 to 20 weight percent tetracalcium aluminoferrite (Ca4Al2Fe2O10). In accordance with an aspect, the catalyst composition may further comprise of one or more of 0 to 1.5 weight percent of MgO, 0 to 1.5 weight percent of Na2O, 0 to 5.4 weight percent of K20 or 0 to 10 weight percent hydrated calcium sulphate.
Alternatively, the catalyst composition may comprise of 14 to 23 weight percent of SiO2, 3 to 6 weight percent of Al2O3, 2.50 to 6 weight percent of Fe203, 43 to 67 weight percent of CaO, 1 to 1.5 weight percent of MgO, 0 to 1.5 weight percent of Na20 and 0 to 5.4 weight percent of K2O.
In accordance with an aspect, the catalyst composite may also contain any inert or active component. The amount of catalyst composition in the catalyst composite material is at least 5 weight percent.

In accordance with an aspect catalyst composition may include cement including but not limited to ordinary cement, Portland cement, white cement, masonary cement, hydraulic and non-hydraulic cements or any other type of cement or their mixture. The composition of cement typically varies within the following composition by 14 to 23 weight percent of SiO2, 3 to 6 weight percent of AI2O3, 2.5 to 6 weight percent of Fe2O3, 43 to 67 weight percent of CaO, 1 to 1.5 weight percent of MgO, 0 to 1.4 weight percent of SO3, 0 to 1.5 weight percent of Na2O and 0 to 5.4 weight percent of K2O.
Cement is a dry powder commonly used as a "binder" material. Binder is a substance that sets or hardens independently and helps bind other materials together. The Portland cement, most commonly used type of cement, is made by heating limestone with small quantities of clay type materials to over 1200 °C in a kiln. The resulting hard substance, called 'clinker', is then ground with a small amount of gypsum into a powder to make Ordinary Portland Cement (often referred to as OPC).
In accordance with an alternate embodiment, the catalyst is a catalyst composite comprising of the catalyst composition and the nano composite catalyst, the catalyst composition comprising of oxides, mixed oxides, silicates or sulphates of two or more of silica, aluminium, iron, calcium, magnesium, sodium and potassium; and the nano composite catalyst having a particle size in the range of 5 nm to 1000 nm and comprising of oxides , mixed oxides, silicates or sulphates of one or more of silica, alumina, calcium and iron.
The catalyst composition may comprise of 25 to 75 weight percent tricalcium silicate (Ca3SiO5), 10 to 40 weight percent dicalcium silicate (Ca2SiO4), 1 to 20 weight percent Tricalcium aluminate (Ca3Al2O6) and 1 to 20 weight percent tetracalcium aluminoferrite (Ca4Al2Fe2O10). In accordance with an aspect, the catalyst composition may further comprise of one or more of 0 to 1.5 weight percent of MgO, 0 to 1.5 weight percent

sf Na20, 0 to 5.4 weight percent of K2O or 0 to 10 weight percent hydrated calcium sulphate.
Alternatively, the catalyst composition may comprise of 14 to 23 weight percent of Si02, 3 to 6 weight percent of AI2O3, 2.50 to 6 weight percent of Fe203, 43 to 67 weight percent of CaO, 1 to 1.5 weight percent of MgO, 0 to 1.5 weight percent of Na20, and 0 to 5.4 weight percent K2O.
The nano composite catalyst may comprise of 25 to 75 weight percent tricalcium silicate (Ca3Si05), 10 to 40 weight percent dicalcium silicate (Ca2Si04), I to 20 weight percent tricalcium aluminate (Ca3Al2O6) and 1 to 20 weight percent tetracalcium aluminoferrite (Ca4Al2Fe2O10).
The catalyst catalyses the transesterification of the fatty acid glycerol esters present in the feedstock as illustrated in the exemplified reaction below:

The catalyst also catalyzes the esterification of fatty acids present in the feedstock as illustrated in the exemplified reaction

The process for production of fatty acid alkyl esters comprises reacting a feedstock that includes one or more fatty acid glycerol esters or one or more fatty acids or mixture thereof with an alcohol at a temperature substantially 100°C or more, in the presence of catalyst, to get a reaction mixture, the catalyst including a catalyst composition comprising of oxides, mixed oxides, silicates or sulphates of two or more of silica, aluminium, iron,

calcium, magnesium, sodium and potassium. The reaction mixture contains a mixture of fatty acid alkyl esters, alcohol and catalyst and fatty acid alkyl esters are recovered from the reaction mixture.
In accordance with an aspect, the catalyst composition comprises of 25 to 75 weight percent tricalcium silicate (Ca3SiO5), 10 to 40 weight percent dicalcium silicate (Ca2SiO4), 1 to 20 weight percent tricalcium aluminate (Ca3Al2O6) and 1 to 20 weight percent tetracalcium aluminoferrite (Ca4Al2Fe2010). hi Accordance with an aspect, the catalyst composition may further comprise of one or mote of 0 to 1.5 weight percent of MgO, 0 to 1.5 weight percent of Na2O and 0 to 5.4 weight percent of K2O or 0 to 10 weight percent hydrated calcium sulphate. Alternatively, the catalyst composition may comprise 14 to 23 weight percent of Si02, 3 to 6 weight percent of A12O3, 2.50 to 6 weight percent of Fe2O3,43 to 67 weight percent of CaO, 1 to 1.5 weight percent of MgO, 0 to 1.5 weight percent of Na20 and 0 to 5.4 weight percent of K2G.
The reaction may be carried out at a temperature in the range of 100°C to 250 °C under autogenerated pressure. The reaction may also be carried out at high pressure of up to 50 bar.
Since alcohol and oils and fats have limited misci'bility in each other, the reaction rates are naturally slow. However, elevated temperature and higher pressure, increases the solubility of the reaction mass (glycerol, monoglycerides, diaglycerides, fatty acid methyl esters) in alcohol. This increases the reaction rates and allows for an efficient reaction in terms of quantity of catalyst required and reaction time.
In accordance with an alternate embodiment, a process for production of fatty acid alkyl esters using a nano composite catalyst is described. The process for production of fatty acid alkyl esters comprises reacting a feedstock that includes one or more fatty acid glycerol esters or one or more fatty acids or mixture thereof with an alcohol in the

presence of catalyst to get a reaction mixture, the catalyst including the nano composite catalyst having a particle size in the range of 5nm to lOOOnm and comprising oxides, mixed oxides, silicates or sulphates of one or more of silica, alumina, calcium and iron. The reaction mixture contains a mixture of fatty acid alkyl esters, alcohol and the catalyst including the nano composite catalyst and fatty acid alkyl esters are recovered from the reaction mixture.
The nano composite catalyst comprises of one or more of Tricalcium silicate (Ca3Sio5), Calcium silicate (CaSiO4), Tricalcium aluminate (Ca3Al2O6) and Tetracalcium aluminoferrite (Ca4Al2Fe2O10). In accordance with an aspect, the composition of the nanocomposite varies within the range 25 to 75 weight percent tricalcium silicate (Ca3SiC>5), 10 to 40 weight percent dicalcium silicate (Ca2Si04), 1 to 20 weight percent tricalcium aluminate (Ca3Al206) and 1 to 20 weight percent tetracalcium aluminoferrite (Ca4Al2Fe2O10).
In accordance with an alternate embodiment, the process for production of fatty acid alkyl esters comprises reacting a feedstock that includes one or more fatty acid glycerol esters or one or more fatty acids or mixture thereof with an alcohol in the presence of catalyst, to get a reaction mixture, the catalyst being a catalyst composite, the catalyst composite comprising the catalyst composition and the nano composite catalyst, the catalyst composition comprising of oxides, mixed oxides, silicates or sulphates of two or more of silica, aluminium, iron, calcium, magnesium, sodium and potassium; and the nano composite catalyst having a particle size in the range of 5nm to lOOOnm and comprising of oxides, mixed oxides, silicates or sulphates of one or more of silica, alumina, calcium and iron. The reaction mixture contains a mixture of fatty acid alkyl esters, alcohol and the catalyst including the catalyst composite and fatty acid alkyl esters are recovered from the reaction mixture.

The catalyst composition may comprise of 25 to 75 weight percent tricalcium silicate (Ca3Si05), 10 to 40 weight percent dicalcium silicate (Ca2Si04), I to 20 weight percent tricalcium aluminate (Ca3Al206) and 1 to 20 weight percent tetracalcium aluminoferrite (Ca4Al2Fe2O10. In accordance with an aspect, the catalyst composition may further comprise of any one or more of 0 to 1.5 weight percent of MgO, 0 to 1.5 weight percent of Na20, 0 to 5.4 weight percent of K20 or 0 to 10 weight percent hydrated calcium sulphate. Alternatively, the catalyst composition may comprise of 14 to 23 weight percent of S1O2, 3 to 6 weight percent of Al2O3, 2.50 to 6 weight percent of Fe2O3, 43 to 67 weight percent of CaO, 1 to 1.5 weight percent of MgO, 0 to 1.5 weight percent of Na20 and 0 to 5.4 weight percent of K2O. The nano composite catalyst may comprise of one or more of Tricalcium silicate (Ca3Sio5), Calcium silicate (CaSiCU), Tricalcium aluminate (Ca3Al2O6) and Tetracalcium aluminoferrite (Ca4Al2Fe2010). In accordance with an aspect, the composition of the nanocomposite varies within the range in 25 to 75 weight percent tricalcium silicate (CasSiOs), 10 to 40 weight percent dicalcium silicate (Ca2SiO4), 1 to 20 weight percent tricalcium aluminate (Ca3Al2O6) and 1 to 20 weight percent tetracalcium aluminoferrite (Ca4Al2Fe2010).
In accordance with an aspect the reaction is carried out in a temperature range of 60°C to 200°C under autogenerated pressure.
In accordance with an aspect, the production of fatty acid alkyl esters comprises of reacting a feedstock that includes one or more fatty acid glycerol esters or one or more fatty acids or mixture thereof with an alcohol in the presence of catalyst, the catalyst including a catalyst composition comprising two or more of oxides, mixed oxides, silicates or sulphates of two or more of silica, aluminium, iron, calcium, magnesium, sodium and potassium at a temperature substantially 100° C and autogenerated pressure for a predetermined period of time to get a reaction mixture, the reaction mixture contains a

mixture of fatty acid alkyl esters, glycerol, alcohol and catalyst; removing the catalyst from the said reaction mixture by filtration or any suitable conventional separation method to get a liquid with two phases, an alcohol containing fatty acid alkyl esters rich layer and alcohol containing glycerol rich layer, separating the two phases and removing the alcohol from alkyl esters and glycerol rich liquids by conventional distillation to get fatty acid alkyl esters and glycerol.
In accordance with an aspect, the production of fatty acid alkyl esters comprises of reacting a feedstock that includes one or more fatty acid glycerol esters or one or more fatty acids or mixture thereof with an alcohol in the presence of catalyst, the catalyst including nano composite catalyst at an elevated temperature and autogenerated pressure for a predetermined period of time to get a reaction mixture, the reaction mixture contains a mixture of fatty acid alkyl esters, glycerol, alcohol and catalyst including nano composite catalyst; removing the catalyst from the said reaction mixture by filtration or any suitable conventional separation method to get a liquid with two phases, an alcohol containing fatty acid alkyl esters rich layer and alcohol containing glycerol rich layer, separating the two phases and removing the alcohol from fatty acid alkyl esters and glycerol rich liquids by conventional distillation to get fatty acid alkyl esters and glycerol.
In accordance with an aspect, the production of fatty acid alkyl esters comprises of reacting a feedstock that includes one or more fatty acid glycerol esters or one or more fatty acids or mixture thereof with an alcohol in the presence of catalyst, the catalyst being a catalyst composite, the catalyst composite comprising a catalyst composition and a nano composite catalyst, the catalyst composition comprising oxides, mixed oxides, silicates or sulphates of two or more of silica, aluminium, iron, calcium, magnesium, sodium and potassium; and the nano composite catalyst having a particle size in the range of 5nm to lOOOnm and comprising oxides, mixed oxides, silicates or sulphates of one or more of

silica, alumina, calcium and iron at an elevated temperature and autogenerated pressure for a predetermined period of time to get a reaction mixture, the reaction mixture contains a mixture of fatty acid alkyl esters, glycerol, alcohol and catalyst; removing the catalyst from the said reaction mixture by filtration or any suitable conventional separation method to get a liquid with two phases, an alcohol containing fatty acid alkyl esters rich layer and alcohol containing glycerol rich layer, separating the two phases and removing the alcohol from fatty acid alkyl esters and glycerol rich liquids by conventional distillation to get fatty acid alkyl esters and glycerol.
In accordance with an aspect, a greater than 98% conversion is achieved by the process and a greater than 99 % conversion is achieved using the catalyst under preferred reaction condition. As the catalyst does not dissolve in the reaction mixture, the quality of the fatty acid alkyl esters and glycerol obtained is purer than most conventional processes.
The catalyst is easily recovered from the reaction mixture by any method including gravitational settling, filtration, centrifugation or any combination thereof.
In accordance with an aspect, once separated, the catalyst may be re-used, if needed, as a catalyst for production of fatty acid alkyl esters without any loss of catalytic activity.
In accordance with an aspect, the catalyst recovered from the reaction mixture may be washed and dried prior to reusing it as a catalyst for the production of fatty acid alkyl esters. The catalyst recovered from the reaction mixture may be washed with any organic solvent in which the organics are soluble. In accordance with an aspect, hydroxylated solvents for example alcohols such as methanol and ethanol are used but less polar organic solvents like hydrocarbons (e.g., hexane) may also be used to selectively remove the alkyl esters. Glycerine left behind with the catalyst may be extracted with water or a

ijydroxylated solvent. Chlorinated solvents such as chloroform, dichloromethane may also be used.
The reaction mixture includes a layer containing fatty acid alkyl esters and alcohol and a layer containing glycerol and alcohol. Recovery of fatty acid alkyl esters from the reaction mixture is carried out by separating the catalyst from the reaction mixture. The fatty acid alkyl esters are recovered from the fatty acid alkyl ester rich layer and separated from the glycerol rich lower layer and alcohol is removed from the two layers. Alternatively, alcohol can be distilled off by simply de-pressuring the reactor at the reaction temperature leaving behind two immiscible liquids in fatty acid alkyl ester and glycerol along with the catalyst.
In accordance with an aspect, the alcohol containing fatty acid alkyl ester rich layer may be separated from the alcohol containing glycerol rich layer by any method including but not limited to gravitational settling, centrifugation, distillation, using separation funnel or a combination thereof. In accordance with an embodiment alcohol is removed from fatty acid alkyl esters and glycerol by vacuum distillation.
The quantity of catalyst required is in the range of 1 to 30 weight percent with respect to the feedstock comprising fatty acid glycerol esters or free fatty acids or mixture thereof. Preferably the quantity of catalyst required is in the range of 2 and 25 weight percent with respect to the feed stock, and most preferably the quantity of catalyst required is in the range of 5 to 10 weight percent with respect to the feed stock.
In accordance with an aspect if less than 5 weight percent of catalyst is used the reaction is carried out at a temperature higher than 160°C to achieve >99% conversion. It is also observed that the molar ratio of feedstock to alcohol is reduced. In accordance with an aspect, the molar ratio of the feedstock to alcohol may be in the range of 3 to 30, or preferably in the range of 7 to 15.

The feed stock used for this process may contain free fatty acids or fatty acid glycerol esters or mixture thereof. The fatty acid glycerol esters may be mono-, di- or tri-ester of glycerol with varying degree of unsaturation in the fatty acid chain. The feedstock used for the production of alkyl esters may be any fatty acid rich material including but not limited to vegetable oil, used vegetable oil, restaurant waste grease, acid oil or surplus liquid or solid fats such as vegetable shortening, surplus margarine or animal fats. Each of these may be used individually or as a mixture.
In accordance with an aspect, additional processing such as removal of excess water or filtering out of precipitate may be required before using animal fat or vegetable oil for this process.
The alcohol to be used for the reaction may be any C5 to C10 alcohol, including but not limited to pentanol, hexanol, heptanol, 2-ethyl hexanol, octanol, decanol. The alcohol used can be primary, secondary or tertiary in nature. Single alcohol or a mixture of two or more alcohols may also be used for the reaction.
Specific embodiments are described below:
A catalyst composite for the production of fatty acid alkyl esters having a C5 to C10 alkyl chain from a feedstock including one or more fatty acid glycerol esters or one or more fatty acids or a mixture thereof, wherein the catalyst composite comprises of a nano composite catalyst having a particle size in the range of 5 nm to 1000 ran and comprising of oxides, mixed oxides, silicates or sulphates of one or more of silica, alumina, calcium and iron.
Such catalyst composite(s) wherein the amount of nano composite catalyst in the catalyst composite is at least 5 weight percent and the remaining may be any inert or active component in the catalyst composite.

Further specific embodiments are described below:
A catalyst composite for the production of fatty acid alkyl esters having a C5 to C10 alkyl chain from a feedstock including one or more fatty acid glycerol esters or one or more fatty acids or mixture thereof, wherein the catalyst composite comprises a catalyst composition comprising of oxides, mixed oxides, silicates or sulphates of two or more of silica, aluminium, iron, calcium, magnesium, sodium and potassium.
Such catalyst composite(s) wherein the amount of catalyst composition in the catalyst composite is at least 5 weight percent and the remaining may be any inert or active component in the catalyst composite.
Such catalyst composite(s) wherein the catalyst composition comprises of cement.
Such catalyst composite(s) wherein the cement is any of Portland cement, white cement, masonary cement, hydraulic and non-hydraulic cements or mixture thereof.
Further specific embodiments are described below:
A catalyst composite for the production of fatty acid alkyl esters having a C5 to C10 alkyl chain from a feedstock including one or more fatty acid glycerol esters or one or more fatty acids or mixture thereof, the catalyst composite comprises a catalyst composition comprising of oxides, mixed oxides, silicates or sulphates of two or more of silica, aluminium, iron, calcium, magnesium, sodium and potassium, and a nano composite catalyst having a particle size in the range of 5 nm to 1000 nm and comprising of oxides, mixed oxides, silicates or sulphates of one or more of silica, alumina, calcium and iron.
Such catalyst composite(s) wherein the nano composite catalyst comprises of 25 to 75 weight percent tricalcium silicate (Ca3SiO5), 10 to 40 weight percent dicalcium silicate (Ca2SiO4), 1 to 20 weight percent tricalcium aluminate (Ca3Al2O6) and 1 to 20 weight percent tetracalcium aluminoferrite (Ca4Al2Fe2O10).

Such catalyst composite(s) wherein the catalyst composition comprises of 25 to 75 weight percent tricalcium silicate (Ca3SiO5), 10 to 40 Weight percent dicalcium silicate (Ca2Si04), 1 to 20 weight percent tricalcium aluminate (Ca3Al2O6) and 1 to 20 weight percent terracalcium aluminoferrite (Ca4Al2Fe2010).
Such catalyst composite(s) wherein the catalyst Composition further comprises of one or more of 0 to 1.5 weight percent of MgO, 0 to 1.5 weight percent of Na2O, 0 to 5.4 weight percent of K2O or 0 to 10 weight percent hydrated calcium sulphate.
Such catalyst composite(s) wherein the catalyst composition comprises of 14 to 23 weight percent of SiO2, 3 to 6 weight percent of A12O3, 2.50 to 6 weight percent of Fe2O3, 43 to 67 weight percent of CaO, 1 to 1.5 weight percent of MgO, 0 to 1.5 weight percent of Na20 and 0 to 5.4 weight percent of K20.
The following examples are provided to explain and illustrate certain preferred embodiments of the process of the invention.
100 g of soybean oil, 225 g of 2-ethylhexanol and 10 g of catalyst (white cement) were put in a batch reactor maintained at 220 C for 6 h under autogenous pressure, the catalyst including a catalyst composition comprising 14 to 23 weight percent of Si02, 3 to 6 weight percent of A1203, 2.50 to 6 weight percent of Fe2O3, 43 to 67 weight percent of CaO, 1 to 1.5 weight percent of MgO, 0 to 1.5 weight percent of Na20 and 0 to 5.4 weight percent of K20. Product mixture was collected and catalyst was filtered off. Two layer of liquid were present, upper layer containing fatty acid alkyl esters (bio-lubricant) and lower layer containing glycerol. Two layers of liquid were separated using separating funnel.
INDUSTRIAL APPLICABILITY
The process as described produces fatty acid alkyl esters useful in bio lubricants in an economically efficient and an environmental friendly manner. As the catalyst is a solid

catalyst, it can be easily separated from the reaction mixture and re-used thereby eliminating the need of neutralization step and aqueous washes that are associated with use of conventional catalysts. Moreover, as the catalyst catalyses both the esterification reaction of the free fatty acids and the transesterification of triglycerides that are present in the fatty acid starting material (free fatty acids and, oils and fats) the process has several advantages. Firstly, the efficiency of the process increases since no acid pre-treatment process and subsequent neutralization steps are needed. Also, fatty acid alkyl esters along with glycerine are generated as the only reaction product without any contaminations. This enables easy separation of the two immiscible layers from the catalyst, yielding fatty acid alkyl esters (bio-lubricant) in quantitative yield that needs no further purification. The contaminations can only come from such sources where the free acid contents are higher than 20 weight percent in the oil, as seen in the case of acid oil. The catalyst separated from the reaction mixture does not lose its catalytic activity and may be reused as a catalyst, thereby reducing the cost of bio-lubricant production.
The embodiments of the invention, described above, are intended to be exemplary, and not limiting. Many variations are possible, within the scope of the invention. These and other modifications are to be deemed within the spirit and scope of the following claims.

WE CLAIM:
1. A catalyst composite for the production of fatty acid alkyl esters having a C5 to C10 alkyl chain from a feedstock including one or more fatty acid glycerol esters or one or more fatty acids or a mixture thereof, wherein the catalyst composite comprises of a nano composite catalyst having a particle size in the range of 5 nm to 1000 nra and comprising of oxides, mixed oxides, silicates or sulphates of one or more of silica, alumina, calcium and iron.
2. A catalyst composite as claimed in claim 1, wherein the amount of nano composite catalyst in the catalyst composite is at least 5 weight percent and the remaining may be any inert or active component in the catalyst composite.
3. A catalyst composite for the production of fatty acid alkyl esters having a C5 to C10 alkyl chain from a feedstock including one or more fatty acid glycerol esters or one or more fatty acids or mixture thereof, wherein the catalyst composite comprises a catalyst composition comprising of oxides, mixed oxides, silicates or sulphates of two or more of silica, aluminium, iron, calcium, magnesium, sodium and potassium.
4. A catalyst composite as claimed in claim 3, wherein the amount of catalyst composition in the catalyst composite is at least 5 weight percent and the remaining may be any inert or active component in the catalyst composite.
5. A catalyst composite as claimed in claim 3, wherein the catalyst composition comprises of cement.

A catalyst composite as claimed in claim 3, wherein the cement is any of Portland cement, white cement, masonary cement, hydraulic and non-hydraulic cements or mixture thereof.
7. A catalyst composite for the production of fatty acid alkyl esters having a C5 to C10
alkyl chain from a feedstock including one or more fatty acid glycerol esters or one
or more fatty acids or mixture thereof, the catalyst composite comprises:
a catalyst composition comprising of oxides, mixed oxides, silicates or sulphates of two or more of silica, aluminium, iron, calcium, magnesium, sodium and potassium; and
a nano composite catalyst having a particle size in the range of 5 nm to 1000 nm and comprising of oxides, mixed oxides, silicates or sulphates of one or more of silica, alumina, calcium and iron.
8. A catalyst composite as claimed in claim 1 or 7, wherein the nano composite catalyst comprises of 25 to 75 weight percent tricalcium silicate (Ca3SiO5), 10 to 40 weight percent dicalcium silicate (Ca2SiO4), 1 to 20 weight percent tricalcium aluminate (Ca3Al2O6) and 1 to 20 weight percent tetracalcium aluminoferrite (Ca4Al2Fe2O10).
9. A catalyst composite as claimed in claim 3 or 7, wherein the catalyst composition comprises of 25 to 75 weight percent tricalcium silicate (Ca3Si05), 10 to 40 weight percent dicalcium silicate (Ca2Si04), 1 to 20 weight percent tricalcium aluminate (Ca3A1206) and 1 to 20 weight percent tetracalcium aluminoferrite (Ca4Al2Fe2O10).

10. A catalyst composite as claimed in claim 9, wherein the catalyst composition further comprises of one or more of 0 to 1.5 weight percent of MgO, 0 to 1.5 weight percent of Na20, 0 to 5.4 weight percent of K20 or 0 to 10 weight percent hydrated calcium sulphate.
11. A catalyst composite as claimed in claim 3 or 7, wherein the catalyst composition comprises of 14 to 23 weight percent of Si02, 3 to 6 weight percent of A1203, 2.50 to 6 weight percent of Fe203, 43 to 67 weight percent of CaO, 1 to 1.5 weight percent of MgO, 0 to 1.5 weight percent of Na20 and 0 to 5.4 weight percent of K20.
12. A catalyst for the production of fatty acid alkyl esters having a C5 to CI 0 alkyl chain substantially as herein described.