FORM 2
THE PATENTS ACT, 1970
(39 of 1970)
&
The Patent Rules, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)
TITLE OF THE INVENTION
"Process for production of monoglycerides and ester of mono alcohols using a novel heterogeneous catalyst and method of preparation of said heterogeneous catalyst"
We, BHARAT PETROLEUM CORPORATION LTD., of Bharat Bhawan, 4 & 6 Currimbhoy, Ballard Estate, Mumbai-400 001, INDIA.
The following specification particularly describes the invention


Process for production of monoglycerides and ester of mono alcohols using a novel heterogeneous catalyst and method of preparation of said heterogeneous catalyst
Field of Invention
The present invention discloses a novel heterogeneous catalyst for trans esterification and/or esterification reactions and method of preparing the same. The disclosed catalyst is successfully employed for the production of methyl esters and mono glycerides using fatty acid esters, vegetable oils, and aliphatic alcohols as reactants.
Background of Invention
Among the alkyl esters of fatty acids, methyl esters, widely known as biodiesel, are synthetic liquid fuels obtained from renewable raw materials and made up of mixtures of long chain fatty acid alkyl monoesters derived from vegetable oils or animal fat. As the produced biodiesel is sulfur free, the use of biodiesel and its blends as a fuel offers significant advantage to refiners to meet the stringent emission norms. The reference international specification for this kind of product is the "Standard Specification for biodiesel Fuel Blend Stock (B100) for Distillate Fuels" defined by the American Society for Testing Materials (ASTM) D6751. The US department of energy has recommended the use of bio-fuel, by themselves or in admixture with other diesel streams in the form of B5, BIO, B20 blends.
Conventionally, biodiesel is produced by means of trans esterification processes where the triglycerides that make up the edible or non-edible oils or the animal fats are made to react with methanol, in the presence of homogeneous acidic or basic catalysts. Generally, the use of base catalyst is reported to be advantageous over acid catalyst in terms of the reaction yield as acid catalysts can cause, depending on the structure of the alcohols which intervene in the process, secondary reactions such as isomerizations or dehydrations. The conventional bases such as KOH, NaOH, alkaline alkoxides such as NaOCH3, NaOC2H5, or NaHCO3, Na2C03, and Ca(OH)2 have been employed for this purpose. Among these, homogeneous base catalysts, sodium methoxide is widely practiced at commercial level for Bio-diesel production. This type of catalyst is difficult to eliminate from the end product and in addition it is not reusable.
U.S. Pat. No. 4,695,411 reveals the production of a fatty acid monoester composition, useful as a fuel for a diesel engine as a replacement of gas oil, using oils or greases of


vegetable or animal origin and four different anhydrous or hydrated alcohols, in the presence of acidic catalyst.
A similar process is described in U.S. Pat. No. 4,364,743, which provides a list of vegetable oils that are made to react with various alcohols in the presence of following homogeneous catalysts such as sodium alkoxide, sodium or potassium hydroxide and titanium tetrahydropropoxide (base catalysts) or the sulfuric, alkyl sulfonic or aryl sulfonic acids (acid catalysts).
U.S. Pat. No. 5,525,126; U.S. Pat. No. 6,015,440; U.S. Pat. No. 6,174,501 and U.S. Pat. No. 6,211,390 also disclose similar processes with modifications in the production steps of other kinds of biodiesel.
Like wise, U.S. Pat. No. 5,578,090; U.S. Pat. No. 6,017,369 and U.S. Pat. No. 6,129,773, demonstrate the technical viability of using several kinds of biodiesel, as such or in admixture with petroleum diesel as a fuel for vehicle or stationary engines. Although homogeneous catalyzed trans-esterification reactions are fast, and show high conversions, the operating costs for purification of the products are higher. The main drawbacks of homogeneously catalyzed trans-esterification reactions are
• Catalysts are hazardous, can not be recovered & the product must be neutralized at the end
• Limited use for continuous processing methodologies
• Processes are very sensitive to moisture, free fatty acids (present in raw oil) and therefore need high quality feed stock to avoid side reactions like saponification and hydrolysis.
• Poor quality of by product (i.e. glycerin)
• Cumbersome purification steps to give required quality of biodiesel fuel.
Due to this the biodiesel production using homogeneous catalyst route demands complicated purification of raw materials or formed products. This often leads to a higher cost/benefit ratio. Therefore it is necessary to have heterogeneous catalysts which are having high activity as compared to the reported catalysts. Therefore, it is of utmost important to investigate a cost-effective and eco-friendly route for biodiesel production. Such efforts have resulted into the successful development of Zinc based heterogeneous catalyst for trans-esterification reaction as disclosed in US pat No. 5,908,946. The process is a two stage trans-esterfication process, in which the alcohol is supplied in excess and removed after each stage. The glycerin is also separated from the ester phase by decanting after each stage. Primarily, this patent discloses zinc aluminate based catalyst for biodiesel production.


Similarly the US pat No. 6,878,837 and 6,147,196 and US Patent application # 20060014974 describes the process development based on catalyst disclosed in US pat No. 5,908,946.
Like wise, the US pat. No. 5,525,126 illustrates a process for bio-diesel production using a mixture of calcium and barium acetate. Similarly, US pat application No. 20050274065 discloses biodiesel production using sodium silicate as heterogeneous catalyst.
However all these patents mainly focus on the edible vegetable oils like soya oil, rapeseed oil, sunflower oil, peanut oil, palm oil, sunflower oil, or used cooking oil as a feedstock for bio-diesel production. The catalyst used in these processes are primarily of zinc aluminates.
Like homogeneous catalysts, heterogeneous catalyst based processes are some times prone to the saponification reaction. The soap so formed increases the difficulties in the separation. This also enhances the cost for biodiesel production. The monoglyceride forms of fatty acids are widely used as emulsifying agents in wide range of applications in food, cosmetic, and pharmaceutical industries. In fact, they account for over 70% of the total world consumption of food emulsifiers. However, the most commonly available monoglycerides in market are of technical grade consisting of a mixture of 40-48% monoglycerides, 30-40% diglycerides, 5-10% triglycerides, 0.2-9% fatty acids and 4-8% glycerol. Pure monoglycerides are available only after isolation by molecular distillation of the technical monoglycerides (Meffert, 1984). These pure monoglycerides are obviously more expensive as compared to the technical products. Their most important application is in food industry due to their excellent self-emulsifying and surface-active properties. Both monoglycerides and their derivatives, depending on the chain length of their fatty acid are also used in non-food applications such as emulsifiers, texturing agents, lubricants and plasticizers in pharmaceuticals, cosmetics and textiles etc.
Generally, there are two routes to the production of monoglycerides, namely the chemical and enzymatic synthesis. Monoglycerides are usually produced by glycerolysis of natural oils and fats at temperatures more than 220°C in the presence of an inorganic catalyst (salts like oxides, hydroxides, carbonates, alkoxides and acetates of alkaline and alkaline-earth metals and nitrogenated bases), the reaction products are in an equilibrium mixture consisting of monoglycerides, diglycerides and triglycerides. However, in general, glycerides used as emulsifiers and/or surface active agents mainly consists of about 90 % of monoglycerides. Hence, in the conventional production of such glycerides, it is necessary to subject a glyceride mixture to


molecular distillation or the like to enhance the content of monoglycerides.
Furthermore, the yield of the conversion of triglycerides to monoglycerides is about
58%. The production of monoglycerides via chemical synthesis can be further improved
by engaging a suitable solvent to increase the solubility of glycerol in the oil and
subsequently enhance the glycerolysis process. Some studies using various polar
solvents such as pyridine, the picolines or isoquinoline, -butanol or tert-amyl alcohol
[K. F Martill (1952), R. J. Sims (1952), EP-1260497 (2002)] to improve yield by
increasing the homogeneity of the reactants, i.e. glycerol and fats have also been
carried out to improve the conversion. However, these solvents caused difficulties due
to odor and toxicity.
In yet another approach, U.S. Pat. No. 6,127,561 discloses a process for the production
of monoglycerides at low temperature under vacuum to improve the yield of
monoglycerides.
The use of heterogeneous basic catalysts greatly simplifies this type of process. The
heterogeneous basic catalyst is easily separated from the reaction medium by
filtration, it allows the possibility of reuse and its application is also possible in fixed
bed processes.
US patent application # 20070037994 describes the use of mixed oxide solids as a base
catalyst for improving the yield and selectivity for monoester formation.
In recent years, synthesis of monoglycerides using lipase enzymes has been actively
investigated. Studies using a wide variety of different enzymes and substrates as well
as conditions to improve the yield of partial glycerides have been carried out. U.S. Pat.
No. 5,270,188 discloses a process of preparation of glycerides having a high content of
monoglycerides with a lipase from Penicilium cyclopium ATCC 34613. Monoglycerides
are produced by mixing glycerol and fatty acids with the lipase under agitation at a
temperature of 20-55 °C. for 1-50 hours.
Although the production of biodiesel and monoglycerides is well documented in
literature, the choice of heterogeneous catalyst is often found to limit the selectivity
and purity of the formed products.
Therefore the present invention discloses a heterogeneous catalyst for the production
of the biodiesel and monoglyceride with high purity and yield with minimum
purification steps.
Objects of Invention
The primary abject of the invention is to disclose a heterogeneous catalyst free from the disadvantages of the prior art.


Another object of the present invention is to disclose a process for making said
heterogeneous catalyst.
Still another object of the present invention is disclose the process of
transesterification and/or esterification using the said heterogeneous catalyst for the
simultaneous production of biodiesel and monoglyceride from edible and/or non-edible
oil sources.
Yet another object of the present invention is to disclose the process for making
biodiesel and monoglyceride with high purity and yield with minimum purification
steps using said heterogeneous catalyst.
Summary of Invention
The present invention discloses a process for production of monoglycerides and ester of mono alcohols from vegetable oil, comprising (a) synthesizing a heterogeneous catalyst comprising (i) oxides of group II elements or their precursor; (ii) promoter selected from a group comprising elements of group IA, group IB, group IIA or combinations thereof or their precursor ; and (iii) support selected from a group comprising elements of group IIIA or group IVA or its precursor; (b) esterification of vegetable oil and/or ester with aliphatic alcohol comprising contacting said vegetable oil and/or said ester, the aliphatic alcohol with said heterogeneous catalyst to form a reaction mixture; (c) removal of the aliphatic alcohol from the reaction mixture to form product mixture; (d) separation of the product mixture into lighter products and heavier products; (e) conversion of the lighter products and heavier products into pure components. In one embodiment of the present invention the synthesis of said heterogenous comprises the steps of: (a) at least single incipient wetness step; and (b) co-precipitation of (i) said oxides of group II elements or their precursor; (ii) promoter selected from a group comprising elements of group IA, group IB, group IIA or combinations thereof or their precursor ; and (iii) support selected from a group comprising elements of group IIIA or group IVA or its precursor.
In another embodiment of the present invention the oxides of group II elements is selected from the group comprising zinc oxide, barium oxide, calcium oxide, or magnesium oxide or combinations thereof in the range of 10-90 wt%, preferably 60-80 wt % .
In still another embodiment of the present invention the promoter is an oxide selected from the group comprising lithium, sodium, potassium, rubidium, cesium, copper, silver, gold or combination thereof, preferably Rubidium oxide or Copper oxide or combinations thereof in the range of 0 to 10 wt%, preferably 0.5 to 4.0 wt %.


In yet another embodiment of the present invention the support is selected from a
group comprising alumina, silica, or combination thereof in the range of 5 to 40 wt %,
preferably 16 to 36 wt % and the precursor is in the form of nitrate.
In another embodiment of the present invention the heterogeneous catalyst has a
selectivity of at least 99% for the production of monoglycerides with promoter and a
selectivity of upto 90 % for the production of monoglycerides without promoter.
In still another embodiment of the present invention the heterogeneous catalyst is in
the form selected from the group comprising powder, pellet, bead, extrudates or
combinations thereof in the size range of 0.2 to 5 mm.
In yet another embodiment of the present invention the step of contacting said
heterogenous catalyst is performed in a multiple fixed bed continuous catalytic reactor
or in CSTR or combinations thereof.
In another embodiment of the present invention the aliphatic alcohol is mono alcohol
or polyalcohol or combination thereof wherein the mono alcohol is preferably methanol
or ethanol and wherein the poly alcohol is preferably glycerin.
In still another embodiment of the present invention the vegetable oil is selected from
the group comprising soya bean oil, rapeseed oil, palm oil, jatropha curcas oil,
pongamia pinnata oil and castor oil or combinations thereof.
In yet another embodiment of the present invention the step of contacting said
heterogenous catalyst is performed at a temperature n the range of 50°C to 300°C,
preferably 180°C to 220 °C and pressure in the range of 5 bar (abs) to 50 bar (abs),
preferably 15 bar (abs) to 25 bar (abs) wherein the wherein the WHSV is in the range
of 0.01 to 5 hr1 preferably 0.5 to 1 hr1.
In another embodiment of the present invention the molar ratio of the aliphatic alcohol
to the vegetable oil is in the range of 3 to 12, preferably 6 to 8.
In still another embodiment of the present invention the reaction mixture comprises
lighter alcohol preferably methanol, heavier alcohol preferably glycerin, mono
glycerides, di glycerides and tri glycerides and alkyl ester of lighter alcohol wherein
the reaction mixture comprises upto 0.01 % by weight of triglycerides, upto 0.1 % by
weight of diglycerides, and upto 0.1 % by weight of glycerin.
In yet another embodiment of the present invention the formation of the product
mixture is performed by means of flash vaporization, distillation, or combination
thereof.
In another embodiment of the present invention the separation of the product mixture
is achieved by means of thermal energy, gravity and centrifugal forces or combinations
thereof.


In still another embodiment of the present invention the lighter product is an alkyl ester of upto 97% purity and the heavier product is an monoglycerides of upto 99% purity.
In yet another embodiment of the present invention the conversion of the lighter products and heavier products into pure components is achieved by thermal route or chemical route preferably by chemical route wherein the chemical conversion is achieved with the heterogeneous catalyst as claimed in any preceding claim. In another embodiment of the present invention the in chemical conversion the lighter product is reacted with lighter alcohol to produce pure lighter product preferably alkyl ester more preferably methyl ester (Purity > 96%) and the heavier product is reacted with heavier alcohol to produce pure heavier product preferably alkyl ester more preferably monoglycerides (Purity 90%).
In still another embodiment of the present invention the chemical conversion of lighter product is performed at temperature in the range of 50C to 300'C, preferably 160'C to 200'C and pressure in the range of 5 bar (abs) to 50 bar (abs), preferably 15 bar (abs) to 25 bar (abs).
In yet another embodiment of the present invention the chemical conversion of the heavier product is performed at temperature in the range of 50'C to 300°C, preferably 200*C to 230'C and pressure 15 bar (abs) to 30 bar (abs).
In another embodiment the present invention discloses a heterogeneous catalyst comprising (i) oxides of group II elements or their precursor; (ii) promoter selected from a group comprising elements of group IA, group IB, group IIA or combinations thereof or their precursor ; and (iii) support selected from a group comprising elements of group IIIA or group IVA or its precursor such as herein described.
Brief Description of figures
Figure. 1. Temperature Programmed Desorption (TPD) curves for A) Li2O/ZnO-Al2O3
B) Na2O/ZnO-Al2O3 C) K2O/ZnO-Al2O3 D) Rb2O/ZnO-Al2O3 E) Cs2O/ZnO-Al2O3.
Figure. 2. The variation of reactor pressure as the function of reaction time, a) ZnRb -2 % Rb20 promoted ZnO/Al2O3 b) ZnBa - 2 % BaO promoted ZnO/Al2O3 c) ZnK - 2 % K2O promoted ZnO/Al2O3 d) ZnNa - 2 % Na2O promoted ZnO/Al2O3 e) ZnLi - 2 % Li2O promoted ZnO/Al2O3 f) ZnCu - 2 % CuO promoted ZnO/Al2O3 g) ZnCs - 2 % Cs2O promoted ZnO/Al2O3 h) ZnO/Al2O3.
Figure. 3: Recycle efficiency (catalyst D/E) for methyl ester production.


Detailed Description of Invention
The heterogeneous catalyst composition comprises of oxides of Group II elements such as Zinc oxide, Barium oxide, Calcium oxide, and Magnesium oxide in the range of 10-90 wt%, with promoter oxides of Group I and/or II elements such as Cs, Li, K, Na, Rb in the range of 0-10 wt % and oxides of support elements such as aluminum, silicon in the range of 5-40 wt% as a binder.
The catalyst composition, useful in the esterification and/or trans-esterification process of this invention, is prepared by a method comprising (a) co-precipitation of oxides of group II precursor, CS2O / Li2O / Na2O/ SrO/ K2O / Rb2O promoter precursors and alumina binder precursors using ammonium / sodium carbonate or ammonium hydroxide as a precipitating agent at 25°C (b) the precipitate is aged overnight either in mother liquor providing a material having the surface area 25-100 m2/g or under hydrothermal /microwave-hydrothermal conditions in the temperature of 110-150'C providing a material having the surface area 50-175 m2/g with high degree of macroporosity. The microwave hydrothermal aging is carried out using MARS-5 unit (CEM Corporation) and hydrothermal aging is performed using high pressure reactor; c) the obtained material is washed, dried and finally calcined in air at 400C. Thus obtained sorbent composition is palletized to form sorbent body in various shapes such as extrudates, granules, beads, etc, in the size range of 0.2 to 5 mm, using clay preferably bentonite and/or alumina binder. The BET surface area for the prepared compositions was estimated by measuring nitrogen uptake at -196'C using Autosorb-1C unit (Quanta chrome, USA). The basicity of the prepared catalyst compositions is evaluated using CO2 adsorption technique (Alta Mira AMI 200). The measured TPD curves for the prepared catalysts are shown in Figure. 1.
The performance of prepared catalyst compositions for trans-esterification process is evaluated as per the following approach both in batch as well as continuous mode. The progress of the reaction is monitored by following the pressure drop as a function of time for various catalyst formulations (Figure. 2) in batch mode.
Typically, about 1-2 gm of catalyst sample on dry basis is mixed with methanol (-15-20 ml) and about 45 gm of non-edible oil in a high pressure reactor. The reactor is purged with inert gas to remove trace oxygen present in the reactor. The reactor is heated up to requisite reaction temperature (150-250°C) and held for 0.01 to 8 hrs. The resultant reacted mixture is then separated from the catalyst and is left overnight to separate lighter and heavier layers under gravitational / centrifugal force. Thus obtained biodiesel product quality is evaluated for its properties as per the ASTM D


6751. Like wise, quality of the formed monoglyceride is evaluated using HPLC method (Haas, M. J., and K. M. Scott, J. Am. Oil Chem. Soc, 73:1393-1401 (1996). Like wise, continuous mode operation is carried out in a fixed bed reactor in continuous flow stirred tank reactor using about 100 g of catalyst. The catalyst is loaded near the centre of the steel column of 1 cm x 35 cm with inert alumina balls at both the ends to avoid any end effects and to maintain the uniform temperature in the catalyst bed. Methanol and non-edible oil are pumped out from the feed tank separately and mixed inline before entering at the reactor bottom. The molar ratio between alcohol to ester is kept around 7. The reaction temperature is 160-250°C and the pressure is 15-25 bar using the WHSV in the range of 0.5-3 hr1. The methanol is removed from the reaction products via. flash evaporation followed by separation of glycerin layer from methyl ester product and un reacted oil. The formed methyl ester phase is re-circulated through reactor bed along with methanol for further conversion of un-reacted oil.
Having summarized the invention, it is now described in detail below by reference to the following description and non-limiting examples.
Examples
Example 1; 61.05 g of Zinc Oxide is mixed with 60 ml of 0.5 M solution of lithium nitrate to form a wet mixture. Then the said mixture is dried at 100°C to form a dry mixture. The above procedure is repeated for 5 times and the resultant dry mixture is heated from room temperature to 150°C, at the rate of 2°C per minute and held at that temperature for 1 hour, then heated to 450°C, at the rate of 2°C per minute and held at that temperature for 10 hours. The material obtained is named as Catalyst-A. Thus obtained catalyst is characterized for its basicity, which is about 0.4 mmol/g.
Example 2; 61.05 g of Zinc Oxide is mixed with 60 ml of 0.5 M solution of sodium and/or potassium and/or rubidium nitrate to form a wet mixture as per the example 1. Then the said above procedure is followed to obtain the catalyst-B, C, D, respectively, having basicity value of about 0.6, 0.8, 1.1 mmol/g.
Example 3: 61.05 g of Zinc Oxide is mixed with 15 ml of 0.5 M solution of cesium nitrate to form a wet mixture. Then the procedure illustrated in example 1 is followed to obtain the catalyst-E having basicity of about 0.9 mmol/g.


Example 4: 70 g of said catalyst-D is loaded inside the steel column of 1 cm of diameter and 35 cm length. Top and bottom of the catalyst bed is covered with 3 g of inert alumina to avoid any end effects and to maintain the uniform temperature in the catalyst bed. Methanol and Jutropha Curcas oil is pumped in separately and mixed inline before entering in to the reactor at the bottom. The molar ratio between methanol and oil is kept around 7. The reaction is carried out at 200 °C and 25 bar with a WHSV (weight hourly space velocity) of 1 hr-1. A conversion level of more than 95 % was achieved. The yield of methyl ester of fatty acid is less than 70 %. The product is found to have less than 0.1 % by weight of triglycerides, less than 1 % by weight of diglycerides and less than 0.1 % by weight of glycerin.
Example 5: The product obtained from the example-4 is cooled to below the room temperature and centrifuged at 10000 rpm to separate the lighter and heavier products.
Example 6; The heavier product obtained from example-5, which is rich in the monoglycerides is mixed with glycerin and passed in to the reactor loaded with the catalyst-D as mentioned in the example - 4 . The mass ratio between alcohol and the heavier product is kept around 0.2. The reaction temperature is 220°C, pressure is 10 bar and the WHSV is 0.5 hr-1. The methanol and glycerin areis removed and the resulting product is found to have more than 95 % of monoglycerides by weight. Like wise, monoglycerides up to 90% by weight is obtained with catalyst-A.
Example 7: The lighter product obtained from example-5, which is rich in the methyl ester is mixed with methanol and passed in to the reactor loaded with the catalyst-D as mentioned in the example-4 . The mass ratio between alcohol and the lighter product is kept around 0.2. The reaction temperature is 180°C, pressure is 20 bar and the WHSV is 0.5 hr-1. The glycerin is removed and the resulting product is found to have more than 98 % of methyl ester by weight.
Example 8: 2 g of said catalyst-E is mixed with 18 ml of methanol to form a mixture. Then the said mixture is mixed with 45 g of Jatropha Curcas oil. Then the said mixture is loaded inside the 100 ml high pressure reactor. Thus the mixture obtained is heated up to 200°C in an inert atmosphere. The conversion is monitored as a function of pressure. When the change in pressure drop is negligible, then the reaction mixture is cooled down to room temperature. Then the unreacted methanol is


evaporated and the glycerin layer is separated from the alkyl-ester layer. The conversion level of about at least 85 wt% is achieved.
Example 9: The catalyst, ZnO/Al2O3 containing 2 % of oxides of promoter such as Lithium, Sodium, Potassium, Rubidium, cesium, Barium and copper was loaded into the reactor as mentioned in the example-5. The reactor pressure was monitored as a function of time and compared with the catalyst having no promoter, as shown in figure. 2.
Example 10: 70 g of said catalyst-D is loaded inside the steel column of 1 cm of diameter and 35 cm length. Top and bottom of the catalyst bed is covered with 3 g of inert alumina to avoid any end effects and to maintain the uniform temperature in the catalyst bed. Methanol and Soya bean oil is pumped in separately and mixed inline before entering in to the reactor at the bottom. The molar ratio between methanol and oil is kept around 7. The reaction is carried out at 200°C and 25 bar with a WHSV of 1 hr-1. A conversion level of more than 95 % was achieved. The yield of methyl ester of fatty acid is less than 70 %. The product is found to have less than 0.1 % by weight of triglycerides, less than 1 % by weight of diglycerides and less than 0.1 % by weight of glycerin. The product obtained is cooled to below the room temperature and centrifuged at 10000 rpm to separate the lighter and heavier products.
Example 11: The heavier product obtained from example-10, which is rich in the monoglycerides is mixed with glycerin and passed in to the reactor loaded with the catalyst-D/E as mentioned in the example-4 . The mass ratio between alcohol and the heavier product is kept around 0.2. The reaction temperature is 220°C, pressure is 10 bar and the WHSV is 0.5 hr-1. The methanol is removed and the resulting product is found to have more than 95 % of monoglycerides by weight.
Example 12: The recycle efficiency of the catalyst D as mentioned in the example-4 is evaluated by monitoring its performance for methyl ester production using Jatropha Curcas oil. The recycle capacity was judged in terms of the kinematic viscosity of the formed methyl ester for about 25 cycles. The measured data for methyl ester samples obtained after each cycle is depicted in Figure 3. The kinematic viscosity data is found to be in the range of 4-6 mm2/s which is found to meet BIS specifications for methyl ester of vegetable oil.


The main advantages of the present invention are:
• Recovery and recycle of the catalyst
• Offers continuous /batch processing methodologies
• Minimal quantity of glycerin
• Zero soap formation
• Minimal formation of di-glycerides
• Easy separation step to give required quality of biodiesel fuel
• Good quality monoglyceride formation


We claim:
1. A process for production of monoglycerides and esters of mono alcohols from
vegetable oil, comprising :
(a) synthesizing a heterogeneous catalyst comprising (i) one or more oxides of group II elements or their precursor; (ii) promoter selected from a group comprising elements of group IA, group IB, combinations thereof or then-precursor ; and (iii) support selected from a group comprising elements of group IIIA or group IVA or its precursor;
(b) esterification of vegetable oil and/or ester with aliphatic alcohol comprising contacting said vegetable oil and/or said ester, said aliphatic alcohol with said heterogeneous catalyst to form a reaction mixture;
(c) removal of the said aliphatic alcohol from the reaction mixture to form product mixture;
(d) separation of said product mixture into lighter products and heavier products; and
(e) conversion of said lighter products and heavier products into pure components.

2. A heterogeneous catalyst comprising (i) one or more oxides of group II elements; (ii) promoter selected from a group comprising elements of group IA, group IB or combinations thereof; and (iii) support selected from a group comprising elements of group IIIA or group IVA for production of monoglycerides and esters of mono alcohols.
3. The heterogeneous catalyst as claimed in claim 2 wherein said heterogeneous catalyst comprises promoted oxides selected from the group comprising of zinc, zinc-aluminium, zinc-magnesium, magnesium-aluminium, zinc-magnesium-aluminium based material on a support.
4. The heterogeneous catalyst as claimed in claim 2 wherein said oxides of group II elements is selected from the group comprising zinc oxide, barium oxide, calcium oxide, or magnesium oxide or combinations thereof in the range of 10-90 wt%, preferably 60-80 wt %.
5. The heterogeneous catalyst as claimed in claim 2 wherein said promoter is an oxide selected from the group comprising lithium, sodium, potassium,


rubidium, cesium, copper, silver, gold or combination thereof, preferably rubidium oxide or Copper oxide or combinations thereof in the range of 0 to 10 wt%, preferably 0.5 to 4.0 wt %.
6. The heterogeneous catalyst as claimed in claim 2 wherein said support is selected from a group comprising alumina, silica, or combination thereof in the range of 5 to 40 wt %, preferably 16 to 36 wt %.
7. The heterogeneous catalyst as claimed in any of the claims 2 to 6 wherein said heterogeneous catalyst has a selectivity of at least 99% for the production of monoglycerides with promoter and said heterogeneous catalyst has a selectivity of upto 90% for the production of monoglycerides without promoter.
8. The heterogeneous catalyst as claimed in any of the claims 2 to 7 wherein said heterogeneous catalyst is in the form selected from the group comprising powder, pellet, bead, extrudates or combinations thereof in the size range of 0.2 to 5 mm.
9. A process for the synthesis of said heterogeneous catalyst comprising the steps of:

(a) at least single incipient wetness step; and
(b) co-precipitation of (i) said oxides of group II elements or their precursor; (ii) promoter selected from a group comprising elements of group IA, group IB or combinations thereof or their precursor ; and (iii) support selected from a group comprising elements of group IIIA or group IVA or its precursor.

10. The process as claimed in claim 9 wherein said oxides of group II elements is selected from the group comprising zinc oxide, barium oxide, calcium oxide, or magnesium oxide or combinations thereof in the range of 10-90 wt%, preferably 60-80 wt%.
11. The process as claimed in claims 9 or 10 wherein said promoter is an oxide selected from the group comprising lithium, sodium, potassium, rubidium, cesium, copper, silver, gold or combination thereof, preferably rubidium oxide or Copper oxide or combinations thereof in the range of 0 to 10 wt%, preferably 0.5 to 4.0wt%.


12. The process as claimed in claims 9 to 11 wherein said support is selected from a group comprising alumina, silica, or combination thereof in the range of 5 to 40 wt %, preferably 16 to 36 wt %.
13. The process as claimed in claims 9 to 12, wherein said precursor is in the form of nitrate.
14. The process as claimed in claims 9 to 13 wherein said heterogeneous catalyst has a selectivity of at least 99% for the production of monoglycerides with promoter and said heterogeneous catalyst has a selectivity of upto 90% for the production of monoglycerides without promoter.
15. The process as claimed in claims 9 to 14 wherein said heterogeneous catalyst is in the form selected from the group comprising powder, pellet, bead, extrudates or combinations thereof in the size range of 0.2 to 5 mm.
16. A process for production of monoglycerides and esters of mono alcohols from vegetable oil, comprising:

(a) transesterification of vegetable oil and/or ester with aliphatic alcohol comprising contacting said vegetable oil and/or said ester and said aliphatic alcohol with said heterogeneous catalyst such as hereinbefore described to form a reaction mixture;
(b) removal of said aliphatic alcohol from said reaction mixture to form product mixture;
(c) separation of said product mixture into lighter products and heavier products; and
(d) conversion of said lighter products and heavier products into pure components.

17. The process as claimed in claim 16 wherein said contacting is performed in a multiple fixed bed continuous catalytic reactor or in continuous stirred tank reactor (CSTR) or combination thereof.
18. The process as claimed in claims 16 or 17 wherein said aliphatic alcohol is mono alcohol or polyalcohol or combination thereof wherein said mono alcohol


is preferably methanol or ethanol and wherein said poly alcohol is preferably glycerin.
19. The process as claimed in claims 16 to 18 wherein said vegetable oil is selected from the group comprising soya bean oil, rapeseed oil, palm oil, jatropha curcas oil, pongamia pinnata oil and castor oil or combinations thereof.
20. The process as claimed in claims 16 to 19 wherein said contacting is performed at a temperature in the range of 50"C to 300'C, preferably 180°C to 220°C; pressure in the range of 5 bar (abs) to 50 bar (abs), preferably 15 bar (abs) to 25 bar (abs) and the WHSV in the range of 0.01 to 5 hr1 preferably 0.5 to 1 hr1.
21. The process as claimed in claims 16 to 20 wherein molar ratio of said aliphatic alcohol to said vegetable oil is in the range of 3 to 12, preferably 6 to 8.
22. The process as claimed in claims 16 to 21 wherein said reaction mixture comprises lighter alcohol preferably methanol, heavier alcohol preferably glycerin, mono glycerides, di glycerides and tri glycerides and alkyl ester of lighter alcohol wherein said reaction mixture comprises less than 0.1 % by weight of triglycerides, less than 1 % by weight of diglycerides, and less than 0.1 % by weight of glycerin.
23. The process as claimed in claims 16 to 22 wherein formation of said product mixture as claimed in claim 16(b) is performed by means of flash vaporization, distillation, or combination thereof.
24. The process as claimed in claims 16 to 23 wherein said separation as claimed in claim 16(c) is achieved by means of thermal energy, gravity and centrifugal forces or combinations thereof.
25. The process as claimed in claims 16 to 24 wherein said lighter product is an alkyl ester of upto 97% purity.
26. The process as claimed in claims 16 to 25 wherein said heavier product is an monoglyceride of upto 99% purity.


27. The process as claimed in claims 16 to 26 wherein said conversion as claimed in claim 16(d) is achieved by thermal route or chemical route preferably by chemical route wherein said chemical route conversion is achieved with said heterogeneous catalyst.
28. The process as claimed in claim 27 wherein in said chemical route conversion said lighter product is reacted with lighter alcohol to produce pure lighter product preferably alkyl ester more preferably methyl ester with purity of at least 98%.
29. The process as claimed in claim 27 wherein in said chemical route conversion said heavier product is reacted with heavier alcohol to produce pure heavier product preferably alkyl ester more preferably monoglycerides with purity of at least 90%.
30. The process as claimed in claim 28, wherein said chemical conversion is performed at temperature in the range of 50"C to 300"C, preferably 160°C to 200"C and pressure in the range of 5 bar (abs) to 50 bar (abs), preferably 15 bar (abs) to 25 bar (abs) and the WHSV is in the range of 0.01 to 5 hr1 preferably 0.5 to 1 hr1.
31. The process as claimed in claim 29, wherein said chemical conversion is performed at temperature in the range of 50"C to 300"C, preferably 200°C to 230°C and pressure in the range of 5 bar (abs) to 50 bar (abs), preferably 5 bar (abs) to 15 bar (abs) and the WHSV is in the range of 0.01 to 5 hr1 preferably 0.5 to 1 hr1.




Process for production of monoglycerides and ester of mono alcohols using a novel heterogeneous catalyst and method of preparation of said
heterogeneous catalyst
ABSTRACT
The present invention relates to the process for production of monoglycerides and ester of mono alcohols from vegetable oil, comprising (a) synthesizing a heterogeneous catalyst comprising (i) oxides of group II elements or their precursor; (ii) promoter selected from a group comprising elements of group IA, group IB or combinations thereof or their precursor ; and (iii) support selected from a group comprising elements of group IIIA or group IVA or its precursor; (b) esterification of vegetable oil or ester with aliphatic alcohol comprising contacting the vegetable oil or said ester, the aliphatic alcohol with the heterogeneous catalyst to form a reaction mixture; (c ) removal of the aliphatic alcohol from the reaction mixture to form product mixture; (d) separation of the product mixture into lighter products and heavier products; and (e) conversion of the lighter products and heavier products into pure components.