Description:Form 2

THE PATENT ACT, 1970
(39 of 1970)
&
THE PATENT RULES, 2003
COMPLETE SPECIFICATION
(See section 10 and rule 13)

“A ONE-POT SUBCRITICAL TRANSESTERIFICATION PROCESS FOR THE TOTAL CONVERSION OF OIL TO BIODIESEL WITHOUT A CATALYST”

in the name of PONDICHERRY UNIVERSITY an Indian National having address at, PONDICHERRY UNIVERSITY, CHINNA KALAPET, KALAPET, PUDUCHERRY, PUDUCHERRY, PUDUCHERRY – 605014, INDIA.

The following specification particularly describes the invention and the manner in which it is to be performed.

SOURCE AND GEOGRAPHICAL ORIGIN OF THE BIOLOGICAL MATERIAL:

SL.
NO COMMON NAME SCIENTIFIC NAME PART OF BIOLOGICAL SOURCES SOURCE OF ACCESS DETAILS OF GEOGRAPHICAL LOCATION
1. Soybean Glycine max Seeds - Oil Market (i) Name of the Market:
Sunrise A-Z Supermarket.

(ii) Contact details: University, Pondicherry University,
Chinna Kalapet, Auroville,
Kalapet,
Puducherry- 605014.
2. Microalgae Schizochytrium limacinum Entire organism - Oil Trader (i) Name of the trader:
AMAZON RETAIL INDIA PRIVATE LIMITED.

(ii) Contact details: Ground Floor,
Eros Plaza,
Eros Corporate Centre, Nehru Place,
New Delhi-110019
Delhi South Delhi DL IN 110019.

https://www.amazon.com/VIRGIN-ALGAE-BOTTLE-Unrefined-Unfiltered/dp/B0B2ZMTSBL
3. Cow Bos taurus Butter Market (i) Name of the Market:
Sunrise A-Z Supermarket.

(ii) Contact details: University, Pondicherry University,
Chinna Kalapet, Auroville,
Kalapet,
Puducherry- 605014.

FIELD OF THE INVENTION:

The present invention generally relates to a biodiesel production process. Specifically, the present invention relates to a one-pot subcritical trans-esterification process for producing biodiesel without a catalyst. More particularly, the present invention relates to a one-pot subcritical trans-esterification process for producing biodiesel without a catalyst by using various feedstocks.

BACKGROUND OF THE INVENTION:

Biodiesel is a renewable transport fuel made mainly from plant/vegetable oils such as soya oil or rape seed oil. It has long been known that diesel engines may be operated on fuel oil derived from plants. The original diesel engine was demonstrated in 1895 operating on fuel derived from peanut oil. Biodiesels are particularly attractive as they have a neutral environmental impact, in that the oils are derived from plants which grow by absorbing carbon dioxide from the atmosphere. Clean burning of diesels fuels releases carbon dioxide into the atmosphere, continuing a cycle in which further oils may be grown for fuel use. Vegetable/plant oils may be converted into biodiesel by a simple transesterification process. The resulting biodiesel (or methyl ester) can be used in any diesel engine.

Although raw vegetable oils may be used as fuels for certain compression ignition internal combustion engines, biodiesel generally refers to oil which has been processed to provide a clean-burning alternative fuel, produced from domestic, renewable resources. Biodiesel can be used on its own or blended in any proportions with petroleum diesel to create a biodiesel blend. Biodiesel, or blends thereof, may be used be used in diesel engines with little or no engine modification. Biodiesel is biodegradable, non-toxic, and has very low levels of sulphur and harmful aromatic compounds. In other words, it is a clean and environmentally friendly fuel.
Biodiesel is derived from natural oil by an esterification process in which raw vegetable oil or animal fat is converted into methyl esters (biodiesel) and glycerin. Glycerin can be a raw material that may be used to make soaps and other products. The term 'biodiesel' basically means an animal or vegetable oil processed to provide fuel grade material. Thus, 'biodiesel' may be formally defined as mono-alkyl esters of long chain fatty acids derived from vegetable oils or animal fats for use in diesel engines.

With mineral oil supplies having finite reserves and being prone to large price variations, there has arisen in recent years renewed interest in the use of plant oils for fuel. These fuels have clear environmental benefits in reducing net carbon dioxide emissions.

There are three established routes by which alkyl esters may be produced from oils and fats. The first is transesterification of the oil by alcohol in the presence of an alkali catalyst such as sodium or potassium hydroxide. Second, acid esterification of the oil by methanol in the presence of an acid catalyst, and third, conversion of the oil into fatty acids and thence alkyl esters by acid catalysis. Of these, the first method dominates current industrial processes because the plant required is simple - low temperatures and pressures are used, conversion rates are high (about 98%) and methyl ester is derived directly with no significant intermediate steps.

There are reports available in the state of the art relating to biodiesel production process in presence of catalyst.

US20040254387A1 discloses a method of making biodiesel comprising the following steps: providing a vegetable oil source comprising free fatty acids, glycerides, or mixtures thereof; providing methanol in an amount between about 1.0 molar equivalent to about 5.0 molar equivalents compared to the total moles of free fatty acids, glycerides, or mixtures thereof; mixing the methanol and the vegetable oil source in the presence of a catalytic acid to form a reaction mixture, wherein the catalytic acid comprises an amount between about 0.1 wt % to about 2 wt % compared to the weight of the vegetable oil source; heating the reaction mixture to a temperature of between about 80° C. to about 200° C.; maintaining a pressure above ambient for the heated reaction mixture; reacting the reaction mixture for a sufficient reaction time to produce a reaction product comprising fatty acid alkyl esters; and recovering the fatty acid alkyl esters.

WO2008049154A1 discloses a process for the production of biodiesel characterized in that it comprises the steps of combining oil or fat with an alcohol in the presence of a catalyst to form a reaction mixture, heating the reaction mixture to above 1000C and raising the pressure of the mixture to above 100 psi, passing the heated and pressurized reaction mixture along a fluid flow path in which turbulent flow is induced to promote a chemical esterification reaction to provide a mixture of biodiesel and glycerine, reducing the pressure of the reacted mixture to about atmospheric pressure and the temperature of the reacted mixture to a temperature lower than the boiling point of the alcohol at atmospheric pressure, and separating the biodiesel and glycerine into separate phases.

US20080209799A1 discloses a method for producing a biodiesel material, the method comprising: conducting an esterification reaction by contacting a feed comprising at least one component selected from the group consisting of a fatty acid, a fatty acid derivative, and combinations thereof, with at least one monohydric alcohol in the presence of a homogeneous catalyst, whereby a reaction mixture comprising at least one ester of the fatty acid and the monohydric alcohol is obtained; subjecting at least a portion of the reaction mixture to a first electrodialysis step, whereby a stream rich in the homogeneous catalyst and a stream depleted in the homogeneous catalyst are obtained, wherein the stream depleted in the homogeneous catalyst is subjected to further processing to yield a biodiesel material; and recycling at least a portion of the stream rich in the homogeneous catalyst to the esterification reaction.

However, conventional biodiesel production process exhibits advantages they do exhibit disadvantages such as relying on catalyst leads to complex and expensive production process, by product glycerol and waste generation, causing potential harm to the environment, limited feedstock flexibility, high energy consumption due to multiple step process and the like.

Thus, there exists a need in the state of art to develop a cost-effective and efficient one-pot subcritical trans-esterification process for biodiesel production.

Hence an attempt has been made to produce biodiesel by simple, cost-effective and efficient one-pot subcritical trans-esterification process without a catalyst.

OBJECT OF THE INVENTION:

The main object of the present invention is to develop a one-pot subcritical trans-esterification process.

Another object of the present invention is to develop a one-pot subcritical trans-esterification process for producing biodiesel.

Another object of the present invention is to develop a one-pot subcritical trans-esterification process for producing biodiesel employing methyl alcohol or ethyl alcohol, feed stocks include vegetable oils, animal fats and microalgae oils.

Yet another object of the present invention is to develop a one-pot subcritical trans-esterification process exhibiting enhanced biodiesel production by eliminating the use of catalyst and eliminating the glycerol and biodiesel separation and purification steps.

Further object of the present invention is to utilize the developed one-pot subcritical trans-esterification process for biodiesel production.

SUMMARY OF THE INVENTION:

The present invention discloses a one-pot subcritical trans-esterification process for the total conversion of oil to biodiesel without a catalyst with simultaneous conversion of glycerol by-product, thereby eliminating financial and environmental costly steps of glycerol and biodiesel separation and purification. The process of the present invention comprises of mixing feed stock with alcohol reagent in a metal pressure reactor and heating within the range of 150°C to 300°C at pressure ranges from 10 to 50 bar, for 60 to 300 minutes for total conversion of oil to biodiesel followed by cooling to form bio-diesel in which excess alcohol reagent is recovered by opening of reactor top valve and conducting alcohol vapor to a condenser and reused for subsequent reactions.

DETAILED DESCRIPTION OF THE INVENTION:

The present invention discloses a one-pot subcritical trans-esterification process for the total conversion of oil to biodiesel without a catalyst with simultaneous conversion of glycerol by-product.

The present invention involves a novel method for producing ethyl or methyl biodiesel without the need for a catalyst, under subcritical thermodynamic conditions of pressure and temperature, using a wide range of feedstocks, including vegetable oils, animal fats and microalgae oils. The only requirement is that the feedstock must be clean, free from particulate matter. They may vary in their composition, but all must contain triglycerides that can be converted into biodiesel.

The proposed process comprises only one-pot reaction, with simultaneous conversion of the glycerol by-product, eliminating the financial and environmental costly steps of glycerol and biodiesel separation and purification to provide economical, efficient and environmentally friendly approach for biodiesel production.

The feedstock is mixed with ethyl alcohol (ethanol) or methyl alcohol (methanol), the alcohol reagents for esterification, introduced into a specialized reaction vessel designed to withstand high pressure and high-temperature conditions. This vessel is typically made of stainless steel with thermal insulation to maintain the desired temperature. The mixture is then heated to the desired temperature, typically within the range of 150°C to 300°C. The subcritical thermodynamic conditions, including pressure and temperature are carefully controlled and monitored throughout the process. The pressure typically ranges from 10 to 50 bar, while the temperature remains within 150°C to 300°C, ensuring the efficient conversion of feedstock into biodiesel. The reaction proceeds for a specified duration, typically ranging from 60 to 300 minutes, to ensure high conversion rates and the completion of the esterification and transesterification processes, as well as the glycerol conversion. After the reaction is complete, the mixture is allowed to cool. During this cooling step, the excess of alcohol is naturally recovered by the careful opening of the reactor top valve, conducting the vapor to a condenser. The alcohol then recovered can be reused in subsequent reactions.

Under the controlled conditions, the esterification and transesterification reactions take place. These reactions break down the triglycerides in the feedstock into esters (biodiesel) and glycerol, without the need for a catalyst.
The present invention simplifies the production process by eliminating the need for catalysts, improving feedstock versatility, enhancing energy efficiency, reduces environmental concerns, and offers economic benefits by eliminating the need for waste management and the associated costs.

The biodiesel produced during trans-esterification process was then subjected to characterization to determine its efficacy.

S.No Property Biodiesel produced from feedstock of the present invention
1. Density at 15 °C kg/m3 882
2. Density at 20 °C kg/m3 876
3. Flash point °C 119
4. Cloud point °C 9
5. Kinematic viscosity at 40 °C mm2/s 5.7
6. Acid value 0.42
7. Water and sediment % (v/v) 0.054
8. Copper strip corrosion, 3 h at100 °C 1

Thus the Biodiesel produced from feedstock of the present invention possess the required properties of the diesel.

Advantages:

Catalyst-Free Process: One of the key innovations of this invention is the elimination of catalysts in the biodiesel production process. By removing the need for catalysts, the invention simplifies the production process, reduces the need for waste management, and decreases the environmental impact of biodiesel production.
Subcritical Thermodynamic Conditions: The process operates under subcritical thermodynamic conditions, with specific pressure and temperature ranges tailored to the desired molecular transformation. This approach allows for more efficient and controlled biodiesel production and may lead to improved conversion rates.

Wide Range of Feedstocks: The invention accommodates a variety of feedstocks, including vegetable oils, animal fats, and microalgae oils. This versatility enables the utilization of various raw materials, making the process adaptable to changing availability and sustainability concerns.

Energy Efficiency: The process is designed to have a positive energy balance, where the energy obtained from the produced biodiesel exceeds the energy input required for the procedure. This positive energy balance (NER>1) highlights the potential for a sustainable and economically viable production method.

Minimal Environmental Impact: The invention promotes clean technology by minimizing waste generation, gaseous emissions, and effluents. It eliminates the need for procedures related to the neutralization and treatment of biodiesel and effluents, contributing to an eco-friendlier production process.

Process Control and Monitoring: The invention emphasizes the importance of monitoring and controlling pressure and temperature variables, ensuring the process's safety and efficiency.

Range of Operation: This process offers the flexibility to operate in both batch and continuous modes, allowing for scalability and adaptability to different production requirements.

Economic Advantages: The elimination of the need for catalysts, the elimination of glycerol and biodiesel separation and purification steps and the associated waste management procedures reduces production costs, making this method economically viable and appealing to biodiesel producers.

In one of the preferred embodiments, the present invention shall disclose a one-pot subcritical trans-esterification process for the total conversion of oil to biodiesel without a catalyst with simultaneous conversion of glycerol by-product, thereby eliminating financial and environmental costly steps of glycerol and biodiesel separation and purification. The process comprises of mixing feed stock with alcohol reagent in a metal pressure reactor and heating within the range of 150°C to 300°C at pressure ranges from 10 to 50 bar, for 60 to 300 minutes for total conversion of oil to biodiesel followed by cooling to form bio-diesel in which excess alcohol reagent is recovered by opening of reactor top valve and conducting alcohol vapor to a condenser and reused for subsequent reactions.

As per the invention, in the one-pot subcritical trans-esterification process of the present invention, the feed stock is selected from a group comprising of vegetable oils, animal fats and microalgae oils.

In accordance with the invention, in the one-pot subcritical trans-esterification process of the present invention, the alcohol reagent is methyl alcohol or ethyl alcohol.

According to the invention, in the one-pot subcritical trans-esterification process of the present invention, the feed stock with alcohol reagent is mixed in a ratio of 1:3.

In accordance with the invention, in the one-pot subcritical trans-esterification process of the present invention, the metal pressure reactor is made of stainless steel with thermal insulation to maintain the desired temperature.

Working example:

One-pot subcritical trans-esterification process for biodiesel production:

The feed stock was mixed with ethyl alcohol reagent in a ratio of 1:3, in a metal pressure reactor and heated within the range of 150°C to 300°C at pressure ranges from 10 to 50 bar, for 60 to 300 minutes for total conversion of oil to biodiesel and cooled to form bio-diesel. The excess alcohol reagent was recovered by opening of reactor top valve and alcohol vapor was conducted to a condenser and reused for subsequent reactions.

Although the invention has now been described in terms of certain preferred embodiments and exemplified with respect thereto, one skilled in art can readily appreciate that various modifications, changes, omissions and substitutions may be made without departing from the scope of the following claims.
, Claims:WE CLAIM:

1. A one-pot subcritical trans-esterification process for the total conversion of oil to biodiesel without a catalyst with simultaneous conversion of glycerol by-product, thereby eliminating financial and environmental costly steps of glycerol and biodiesel separation and purification, the claimed process comprises of mixing feed stock with alcohol reagent in a metal pressure reactor and heating within the range of 150°C to 300°C at pressure ranges from 10 to 50 bar, for 60 to 300 minutes for total conversion of oil to biodiesel followed by cooling to form bio-diesel wherein excess alcohol reagent is recovered by opening of reactor top valve and conducting alcohol vapor to a condenser and reused for subsequent reactions.
2. The one-pot subcritical trans-esterification process as claimed in claim 1, wherein the said feed stock is selected from a group comprising of vegetable oils, animal fats and microalgae oils.
3. The one-pot subcritical trans-esterification process as claimed in claim 1, wherein the said alcohol reagent is methyl alcohol or ethyl alcohol.
4. The one-pot subcritical trans-esterification process as claimed in claim 1, wherein the said feed stock with alcohol reagent is mixed in a ratio of 1:3.
5. The one-pot subcritical trans-esterification process as claimed in claim 1, wherein the said metal pressure reactor is made of stainless steel with thermal insulation to maintain the desired temperature.

Dated this 08th day of MAY 2024

For PONDICHERRY UNIVERSITY
By its Patent Agent
Dr.B.Deepa
IN/PA 1477