Description:FIELD OF THE INVENTION
The present invention relates to renewable energy, in particular relates to a catalyst for in-situ carbon oxide reduction in biofuel production. More particularly, the present invention relates to a method for preparing the catalyst for the selective reduction of carbon oxides in the presence of Sulfur originating from the decarbonylation reaction in biofuel production. Also relates to a method for in-situ CO reduction in biofuel production utilizing the catalyst.
BACKGROUND OF THE INVENTION
Biomass-based aviation fuel is a prominent choice for reducing operating costs and minimize environmental impact in the airline sector. Significant studies have investigated four primary catalytic methods for creating bio-jet fuel: oil-to-jet, gas-to-jet, alcohol-to-jet, and sugar-to-jet.

Oil-to-jet involves deoxygenation and hydrocracking of triglycerides, while gas-to-jet includes gasification and Fischer-Tropsch synthesis. Alcohol-to-jet consists of alcohol dehydration and oligomerization, and sugar-to-jet involves the biological or catalytic upgrading of sugars.

The oil-to-jet technology is currently accessible in the commercial market, and the bio-jet fuel produced has been successfully tested for commercial and military flights. This bio-jet fuel has reduced aromatic and sulfur contents in comparison to conventional petroleum-derived jet fuel. It is approved for blending with regular jet fuel, with a maximum allowance of 50%.

Oil-to-jet processes typically comprise several reaction steps. During the initial stage, the hydro-processing of glycerides entails both the hydrogenation of double bonds within the side chains and the extraction of oxygen occurring at the metal site of the catalyst. The glycerides are first saturated through hydrogenation with hydrogen input.

The propane backbone is then removed from the hydrogenated glycerides which forms free fatty acids (FFAs).

The produced FFAs are then converted into straight-chain alkanes through the deoxygenation process, which includes hydro-deoxygenation (HDO), decarboxylation (DCO2) and decarbonylation (DCO).

Certain levels of hydro-cracking/isomerization is accompanied with the deoxygenation process. The oxygen is removed from the FFAs through HDO, DCO2 and DCO with the formation of H2O, CO2 and CO, respectively, which produce Cn+1H2n+4, CnH2n+2 and CnH2n+2. This indicates that DCO2 and DCO produce the alkanes with the carbon numbers less than those of original FFAs by one.

During the decarbonylation reaction, carbon monoxide (CO) is formed. In the trijet process, the recirculated gas causes a continuous accumulation of CO in the reactor. The produced CO creates a threat of metal component poisoning, causing a noticeable disproportion between the metal and acid roles in the hydrocracking phase. This disproportion leads to substantial over-cracking of hydrocarbons, resulting in the excessive production of light gaseous substances and the swift deactivation of the catalyst due to coke formation.
To lower production costs and widen the availability of these bio-jet fuels, strategies aimed at minimizing the carbon oxide emission are crucial and worked upon. One promising approach is utilizing hydrogenated catalyst for reduced or selective amount of carbon oxides emission.
SUMMARY OF THE INVENTION
This summary is provided to introduce a selection of concepts in a simplified format that are further described in the detailed description of the invention.
In an aspect of the present invention, there is provided a catalyst for in-situ CO reduction in biofuel production, the catalyst comprising a porous catalyst carrier support selected from the group comprising Al2O3, SiO2-A12O3, CeO2-Al2O3, MgO2-Al2O3, ZrO2-Al2O3, and combinations thereof, a metal selected from the group comprising Ni, Mo, P and combinations thereof, and a peptizing agent along with pseudoboehmite.

In another aspect of the present invention, there is provided a method for preparing a catalyst for CO reduction in biofuel production, the method comprising the steps a) preparing a catalytic carrier support and b) impregnating the catalytic carrier support with a metal solution.

In yet another aspect of the present invention, there is provided a method for preparing a catalyst for CO reduction in biofuel production, wherein the step a) preparation of catalytic carrier support comprises mixing a catalytic carrier material and carrier precursor to obtain a mixture, the mixture is stirred. Followed by adding sodium carbonate to the mixture to maintain pH. Followed by cooling the mixture to obtain a precipitate, washing, and drying the precipitate. Calcining the dried precipitate to obtain catalytic carrier support.

In still another aspect of the present invention, there is provided a method for preparing a catalyst for CO reduction in biofuel production, wherein the step b) the impregnation of the catalytic carrier support with a metal solution comprises mixing metal with precursor and organic acid in distilled water to prepare a homogeneous NiMoP solution, injecting the NiMoP solution into the catalytic carrier support, incubating , evaporating the mixture to obtain a powdered mixture. Followed by drying the powdered mixture, calcinating the dried mixture and blending the calcined powder with an acidic peptizing agent along with pseudoboehmite to obtain a paste. Followed by extruding the paste to obtain an extrudate, drying the extrudate and calcinating the dried extrudate to obtain a catalyst.

In still another aspect of the present invention, there is provided method for in-situ CO reduction in biofuel production, the method comprising mixing of feedstock with sulfur source, subjecting the feedstock to sulfidation process, and loading catalyst beneath the bed of trijet catalyst to obtain CO-reduced fuels.

These and other features, aspects, and advantages of the present subject matter will be better understood with reference to the following description and appended claims. This summary is provided to introduce a selection of concepts in a simplified form. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.
OBJECTIVES OF THE PRESENT INVENTION
The principal objective of the present invention is to prepare a catalyst for reducing CO in biofuel production.
Another objective of the present invention is to develop a method for preparation of catalyst for reducing CO in biofuel production.
Still another objective of the present invention is to develop a method for in-situ CO reduction in biofuel production.

BRIEF DESCRIPTION OF THE DRAWING
Figure 1 illustrates the schematic presentation of single step CO reduced Trijet fuel process.
Figure 2 illustrates the durability study for prepared catalyst.

DETAILED DESCRIPTION OF THE INVENTION
For the purpose of promoting an understanding of the principles of the invention, reference will now be made to the embodiments in the specific language to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, such alterations and further modifications in the illustrated culture blend, and such further applications of the principles of the invention as illustrated therein being contemplated as would normally occur to one skilled in the art to which the invention relates. Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skilled in the art to which this invention belongs. The composition, methods, and examples provided herein are illustrative only and not intended to be limiting.
The articles “a”, “an” and “the” are used to refer to one or to more than one (i.e., to at least one) of the grammatical object of the article.
The terms “comprise” and “comprising” are used in the inclusive, open sense, meaning that additional elements may be included. It is not intended to be construed as “consists of only”.
Throughout this specification, unless the context requires otherwise the word “comprise”, and variations such as “comprises” and “comprising”, will be understood to imply the inclusion of a stated element or step or group of elements or steps but not the exclusion of any other element or step or group of elements or steps.
Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this disclosure belongs. Although any methods and materials similar or equivalent to those described herein can be used in the practice or testing of the disclosure, the preferred methods and materials are now described. All publications mentioned herein are incorporated herein by reference.
The terminology and structure employed herein is for describing, teaching, and illuminating some embodiments and their specific features and elements and does not limit, restrict, or reduce the spirit and scope of the invention.
The term “optionally,” as used in the present disclosure, means that a feature or element described as ‘optional’ within the context of the invention is not required for the invention to function as claimed. It indicates that the presence or absence of the described feature or element does not alter the fundamental operation or scope of the invention, and its inclusion or exclusion may be determined based on the specific requirements or preferences of a practitioner skilled in the art or the particular application in question.
As used herein, the term “biofuel” refers to liquid fuels suitable for vehicles and/or chemical products using biomass-derived liquids.
As used herein, the term “trijet fuel” refers to a liquid fuels like bio diesel, Sustainable aviation fuel which is generated from Bio-Oil (in the form of triglycerides)
As used herein, the term “peptizing agent” refers to its amount and nature have also an impact on the extrusion process and properties of the extrudates examples like HNO3, CH3COOH etc.
As used herein, the term “Used cooking oil” refers to oils and fats that have been used for cooking or frying in the food processing industry, restaurants, and households.
As used herein, the term “sulfidation” refers to a process involves passing feed spiked with a sulfiding agent over the catalyst bed in a carefully controlled procedure that includes several temperatures holds. As the feed and sulfur spiking agent are heated in the presence of hydrogen and the catalyst, the sulfur compound will readily decompose to form the H2S required to complete the sulfiding reactions.
As used herein, the term “calcinating” refers to a process of heating some solid material or a substance in a controlled environment.
As used herein, the term “trijet process” refers to a process in which conversion of Triglycerides to Jet fuel production.
As used herein, the term “trijet catalyst” refers to a catalyst which is used in the production of Jetfuel from Bio oil (Triglycerides).
The present invention discloses a catalyst for in-situ CO reduction in biofuel production, method for preparing a catalyst for CO reduction in biofuel production, the method comprising the steps a) preparing a catalytic carrier support and b) impregnating the catalytic carrier support with a metal solution. The present invention also discloses the method for in-situ CO reduction in biofuel production.
In an embodiment, the present invention provides a catalyst for in-situ CO reduction in biofuel production comprising a porous catalyst carrier support, a metal precursor selected from the group comprising Ni, Mo, P and a peptizing agent and combinations thereof.

In a preferred embodiment, the present invention provides a catalyst for in-situ CO reduction in biofuel production wherein the carrier support is selected from the group comprising Al2O3, SiO2-A12O3, CeO2-Al2O3, MgO2-Al2O3, ZrO2-Al2O3, and combinations present in an amount of 50% to 80%, wherein the metal precursor selected from the group comprising Ni, Mo, P and combinations thereof, wherein the NiMoP is present in an amount of 20 % to 30 %, wherein peptizing agent along with binder pseudoboehmite is present in an amount of 15 % to 25 %.

In another embodiment, the present invention provides a catalyst for in-situ CO reduction in biofuel production, wherein the ratio of carrier support silicon dioxide- Aluminium oxide is 4:6, wherein the ratio of catalytic carrier support to metal to pseudoboehmite is 55:25:20.

In another embodiment, the present invention provides a catalyst for in-situ CO reduction in biofuel production, wherein the catalyst has a total surface area of 193.4 (m2/g), a total pore volume of 0.562 (cc/g), and an average pore radius of 70.6 (Å).

In yet another embodiment, the present invention provides a method for preparing a catalyst for CO reduction in biofuel production, the method comprising a) preparing a catalytic carrier support and b) impregnating the catalytic carrier support with a metal solution.

In still another embodiment, the present invention provides a method for preparing a catalyst for CO reduction in biofuel production, wherein the preparation of catalytic carrier support comprises:
i. mixing a carrier material and carrier precursor to obtain a mixture;
ii. stirring the mixture obtained in step i) at 300 rpm to 400 rpm at a temperature of 50 ºC to 70 ºC;
iii. adding sodium carbonate to the mixture obtained in step ii) to maintain pH at 7.5 to 8.5;
iv. cooling the mixture obtained in step iii) to obtain a precipitate;
v. washing the precipitate obtained in step iv);
vi. drying the precipitate obtained in step v) at 80 °C to 100 °C for 10 hours to 14 hours; and
vii. calcining the dried precipitate obtained in step vi) at 400 oC to 600 °C for 3 hours to 5 hours to obtain catalytic carrier support.

In still another embodiment, the present invention provides a method for preparing a catalyst for CO reduction in biofuel production, wherein the impregnation of the catalytic carrier support with a metal solution comprises:
i. mixing metal with precursor in an amount of 20% to 30% and organic acid in 400 g to 600 g of distilled water to prepare a homogeneous NiMoP solution;
ii. injecting the NiMoP solution into the catalytic carrier support obtained in step a;
iii. incubating the mixture at room temperature for 30 minutes to 120 minutes at temperature from 20 ? to 50 ?;
iv. evaporating the mixture to obtain a powdered mixture;
v. drying the powdered mixture at 100 °C to 150 °C for 10 hours to 14 hours;
vi. calcinating the dried mixture at 400 °C to 600 °C for 2 hours to 6 hours to obtain calcinated powder;
vii. blending the calcined powder with an acidic peptizing agent and pseudoboehmite to obtain a paste;
viii. extruding the paste to obtain an extrudate;
ix. drying the extrudate at 120 °C; and
x. calcinating the dried extrudate at 400 oC to 600 °C for 2 hours to 6 hours to obtain a catalyst.

In still another embodiment, the present invention provides a method for preparing a catalyst for CO reduction in biofuel production, wherein the extruding the paste at room temperature.

In still another embodiment, the present invention provides a method for preparing a catalyst for CO reduction in biofuel production, wherein the organic acid is selected from citric acid, hydroxycitric acid, itaconic acid, mesaconic acid, citraconic acid, aconitic acid, hibiscus acid, glutamic acid, nitrilotriacetic acid, ethylene diamino tetraacetic acid, 1,2-diaminopropane-N,N,N,N -tetraacetic acid, cyclohexane-1,2 diamine tetraacetic acid.

In still another embodiment, the present invention provides a method for in-situ CO reduction in biofuel production the method comprising mixing of feedstock with Sulfur source to maintain a total sulfur concentration of 2000 ppm, wherein the sulfur source is Dimethyl disulfide (DMDS), followed by subjecting the feedstock to sulfidation process at 350°C for 20 hours and loading prepared catalyst beneath the bed of trijet catalyst in a ratio 1:3 to obtain CO-reduced fuels.

In still another embodiment, the present invention the present invention provides a method for in-situ CO reduction in biofuel production, wherein the fuel is Sustainable Aviation Fuel (SAF) or Green Diesel (GD).

In still another embodiment, the present invention the present invention provides a method for in-situ CO reduction in biofuel production, wherein the feedstock selected from the group comprising used cooking oil as feedstock, wherein the feedstock is selected from used cooking oil (UCO), palm oil, jatropha oil, karanja oil, sunflower oil, cottonseed oil, soybean oil, mustard oil, coconut oil, rapeseed oil, tall oil.

EXAMPLES
Example 1. Preparation of NiMoP / Si : Al (4:6) catalyst
Step 1. Preparation of silica-alumina support by sequential precipitation method
A silica-alumina support was prepared by sequential precipitation, and the molar ratio of SiO2:Al2O3 was fixed at 4: 6 (Si:Al).

1.2 moles of Sodium aluminate (NaAlO2) mixed with distilled water to obtain solution A, 0.5 moles of Aluminum sulfate (Al2SO4) as an alumina precursor in distilled water gives solution B contain and 0.45 moles of Sodium silicate (Na2O.3SiO2) as a silica precursor in distilled water gives solution C.

Initially, Solution B mix with solution C by dropwise to bring pH of the solution at 3.0 and the mixture was stirred at 350 rpm while maintaining the temperature at 65 °C. After completing partial precipitation solution A is added dropwise to bring pH at 3.5 with same rpm and precipitating temperature.

Finally, the pH of the solution is brought to 8.1 by using 0.5 moles of sodium carbonate (Na2CO3) solution. The temperature of the reaction solution was lowered to room temperature, and the resulting precipitate was washed with hot water and powder recovered by vacuum filtration, followed by drying at 90 °C for 12 hours. Finally calcined at 500 oC for 4 hours in an air atmosphere.

Step 2. Preparation of NiMoP supported catalyst.

A catalyst was prepared by impregnating the silica-alumina support prepared in step 1 with NiMoP precursor by a wet impregnation method.

Ammoniumheptamolibdate as a precursor of Mo in an amount of 8.4 g and 17.97 g of Nickel nitrate as a precursor of Ni metal and 8.77 g of H3PO4 (85%) as a precursor of P and citric acid, (wherein the mole ratio of citric acid to Ni is 1) were uniformly mixed in 500 g of distilled water to prepare a homogeneous solution.
The NiMoP solution was injected into the Si40Al60 support, aged/incubated at room temperature for 1 hour, followed by rota vaporization to remove excess of water. Resulted powder was dried at 120 ° C for 12 hours and calcined at 500 ° C for 4 hours in an air atmosphere.

For forming extrudates, the calcined powder was blended with 20 % of acidic peptizing agent along with pseudoboehmite. This paste was extruded and dried in an oven at 120 °C followed by calcination at 500 oC for 4 hours. As a result, catalyst named as NiMoP / Si40Al60.

Example 2. Preparation of NiMoP / Zr:Al (4:6) catalyst

Step 1. Preparation of zirconia-alumina support by coprecipitation method

The same apparatus and coprecipitation method as that employed in Example 1 were used to test the activity of a catalyst containing a relatively ZrO2:Al2O3 mole ratio of 4:6 (Zr40Al60).

0.5 moles of Aluminum sulfate (Al2SO4) as an alumina precursor mixed with distilled water to obtain solution A, 0.45 moles of Zirconiumoxychloride (ZrOCl2) as a zirconia precursor in distilled water gives solution B.

Initially, Solution A mix with solution B and the mixture was stirred at 350 rpm at temperature at 65 ° C to obtain a homogenous solution. To the homogenous solution 0.5 moles of sodium carbonate (Na2CO3) solution is added to bring the pH of the solution to 8.1. The temperature of the reaction solution was lowered to room temperature, and the resulting precipitate was washed with hot water and powder recovered by vacuum filtration, followed by drying at 90 ° C for 12 hours. Finally calcined at 500 oC for 4 hours in an air atmosphere.

Step 2. Preparation of NiMoP supported catalyst.

A catalyst was prepared by impregnating the zirconia-alumina support prepared in step 1 with NiMoP precursor by a wet impregnation method.
18.4 g of Ammoniumheptamolibdate as a precursor of Mo and 17.97 g of Nickel nitrate as a precursor of Ni metal and 8.77 g of H3PO4 (85%) as a precursor of P and citric acid (citric acid/Ni mole ratio. 1) were uniformly mixed in 500 g of distilled water to prepare a homogeneous solution.

The NiMoP solution was injected into the Zr40Al60 support, aged/incubated at room temperature for 1 hour, followed by rota vaporization to remove excess of water. Resulted powder was dried at 120 ° C for 12 hours and calcined at 500 ° C for 4 hours in an air atmosphere. For forming extrudates, the calcined powder was blended with 20 % of acidic peptizing agent along with pseudoboehmite. This paste was extruded and dried in an oven at 120 °C followed by calcination at 500 oC for 4 hours. As a result, catalyst named as NiMoP / Zr40Al60.

Example 3. Preparation of NiMoP / Ce:Al (4:6) catalyst

Step 1. Preparation of Ceria-alumina support by Co precipitation method
The same apparatus and coprecipitation method as that employed in Example 1 were used to test the activity of a catalyst containing a relatively CeO2:Al2O3 mole ratio of 40:60 (Ce40Al60).

0.5 moles of Aluminum sulfate (Al2SO4) as an alumina precursor is mixed with distilled water to give solution A and 0.45 moles of Cerium Nitrate (Ce (NO3)2.6H2O) as a Ceria precursor mixed with distilled water to give solution B.

Initially, Solution A is mixed with solution B and the mixture was stirred at 350 rpm at temperature at 65 ° C to obtain a homogenous solution. 0.5 moles of sodium carbonate (Na2CO3) solution are mixed with homogenous solution to bring the pH of the solution to 8.1 by using.

The temperature of the reaction solution was lowered to room temperature, and the resulting precipitate was washed with hot water and powder recovered by vacuum filtration, followed by drying at 90 ° C for 12 hours. Finally calcined at 500 oC for 4 hours in an air atmosphere.

Step 2. Preparation of NiMoP supported catalyst.

A catalyst was prepared by impregnating the zirconia-alumina support prepared in step 1 with NiMoP precursor by a wet impregnation method.

18.4 g of Ammoniumheptamolibdate as a precursor of Mo and 17.97 g of Nickel nitrate as a precursor of Ni metal and 8.77 g of H3PO4 (85%) as a precursor of P and citric acid (citric acid/Ni mole ratio. 1) were uniformly mixed in 500 g of distilled water to prepare a homogeneous solution.

The NiMoP solution was injected into the Ce40Al60 support, aged at room temperature for 1 hour, followed by rota vaporization to remove excess of water. Resulted powder was dried at 120 ° C for 12 hours and calcined at 500 ° C for 4 hours in an air atmosphere. For forming extrudates, the calcined powder was blended with 20 % of an acidic peptizing agent along with pseudoboehmite. This paste was extruded and dried in an oven at 120 °C followed by calcination at 500 oC for 4 hours. As a result, catalyst named as NiMoP / Ce40Al60.

Example 4. Preparation of NiMoP / Mg:Al (4:6) catalyst

Step 1. Preparation of Magnesium-alumina support by Co precipitation method

The same apparatus and coprecipitation method as that employed in Example 1 were used to test the activity of a catalyst containing a relatively MgO2:Al2O3 mole ratio of 40:60 (Mg40Al60).

0.5 moles of Aluminum sulfate (Al2SO4) as an alumina precursor is mixed with distilled water to give Solution A and 0.45 moles of Magnesium Nitrate (Mg (NO3)2.6H2O) as a Ceria precursor mixed with distilled water to give solution B.

Initially, Solution A mix with solution B and the mixture was stirred at 350 rpm while maintaining the temperature at 65 ° C to obtain a homogenous solution. To the homogenous solution 0.5 moles of sodium carbonate (Na2CO3) solution is added to bring the pH of the solution to 8.1.

The temperature of the reaction solution was lowered to room temperature, and the resulting precipitate was washed with hot water and powder recovered by vacuum filtration, followed by drying at 90 ° C for 12 hours. Finally calcined at 500 oC for 4 hours in an air atmosphere.

Step 2. Preparation of NiMoP supported catalyst.

A catalyst was prepared by impregnating the zirconia-alumina support prepared in step 1 with NiMoP precursor by a wet impregnation method.

18.4 g of Ammoniumheptamolibdate as a precursor of Mo and 17.97 g of Nickel nitrate as a precursor of Ni metal and 8.77 g of H3PO4 (85%) as a precursor of P and citric acid (citric acid/Ni mole ratio. 1) were uniformly mixed in 500 g of distilled water to prepare a homogeneous solution.

The NiMoP solution was injected into the Mg40Al60 support, aged/incubated at room temperature for 1 hour, followed by rota vaporization to remove excess of water. Resulted powder was dried at 120 °C for 12 hours and calcined at 500 °C for 4 hours in an air atmosphere. For forming extrudates, the calcined powder was blended with 20 % of an acidic peptizing agent along with pseudoboehmite. This paste was extruded and dried in an oven at 120 °C followed by calcination at 500 oC for 4 hours. As a result, catalyst named as NiMoP / Mg40Al60.

Example 5. Preparation of NiMoP /AlO catalyst
Comparative studies done with and without addition of secondary porous carrier or dopants.

Step 1. Preparation of Alumina support by precipitation method

The same apparatus and precipitation method as that employed in Example 1 were used to test the activity of a catalyst containing pure Al2O3 (AlO) support. The catalyst employed was prepared as follows:

0.5 moles of Aluminum sulfate (Al2SO4) as an alumina precursor is mixed with distilled water to give solution A, to this solution 0.5 moles of sodium carbonate (Na2CO3) solution is added dropwise to bring pH of the final solution at 8.1and the temperature was maintained at 65 oC and stirring maintained at 350 rpm.

The temperature of the reaction solution was lowered to room temperature, and the resulting precipitate was washed with hot water and powder recovered by vacuum filtration, followed by drying at 90 ° C for 12 hours. Finally calcined at 500 oC for 4 hours in an air atmosphere.

Step 2. Preparation of NiMoP supported catalyst.

A catalyst was prepared by impregnating the zirconia-alumina support prepared in step 1 with NiMoP precursor by a wet impregnation method.

18.4 g of Ammoniumheptamolibdate as a precursor of Mo and 17.97 g of Nickel nitrate as a precursor of Ni metal and 8.77 g of H3PO4 (85%) as a precursor of P and citric acid (citric acid/Ni mole ratio. 1) were uniformly mixed in 500 g of distilled water to prepare a homogeneous solution.

The NiMoP solution was injected into the Al2O3 support, aged/incubated at room temperature for 1 hour, followed by rota vaporization to remove excess of water. Resulted powder was dried at 120 ° C for 12 hours and calcined at 500 ° C for 4 hours in an air atmosphere. For forming extrudates, the calcined powder was blended with 20 % of an acidic peptizing agent along with pseudoboehmite. This paste was extruded and dried in an oven at 120 °C followed by calcination at 500 oC for 4 hours. As a result, catalyst named as NiMoP /AlO.

Example 6 Textural Properties of Synthesized Catalyst

The catalysts' BET surface area, pore size, and pore volumes were determined using N2 adsorption-desorption at -196°C on Quantachrome Autosorb IQ equipment. Before analysis, the samples were degassed at 250°C for 3 hours to eliminate impurities or moisture. The surface area of the catalyst was calculated using the Brunauer-Emmett-Teller (BET) method and ranged from 100 to 195 m2/g.

The pore size distribution was determined using the Barret-Joyner-Halenda (BJH) desorption method, revealing a total pore volume between 0.4 to 0.7 cm3/g and an average pore size ranging from 4 to 7 nm. The catalyst produced through this method offers a well-dispersed active phase for effective catalytic performance.

Table 1. BET properties of the synthesized catalyst
Catalyst Active components Total
Surface Area
(m2/g) Total Pore Volume
(cc/g) Average Pore Radius
(Å)
Example 1 Ni/Mo/P/Si40Al60 193.4 0.562 70.6
Example 2 Ni/Mo/P/Zr40Al60 177.1 0.564 61.4
Example 3 Ni/Mo/P/Ce40Al60 102.4 0.548 42.4
Example 4 Ni/Mo/P/Mg40Al60 162.4 0.445 51.2
Example 5 Ni/Mo/P/AlO 172.2 0.432 41.4

Example 7 characterization of bio-oil

In this invention prepared catalyst along with Trijet catalyst subjected selectively preparing a variety of transportation fuels from the biomass feedstock. Wherein, the said feedstock is selected from Used cooking oil (UCO), Palm oil, Jatropha oil, Karanja oil, Sunflower oil, Cottonseed oil, Soybean oil, Mustard oil, Coconut oil, Rapeseed oil, Tall oil.

In case, when Used Cooking Oil (UCO) is taken as the feedstock, the characterization of the UCO shows following results: Elemental analysis and SIMDIST of UCO

Table 2. UCO properties
Properties of Used cooking oil Units Values
Density at 25 oC g/cc 0.923
Kinematic viscosity at 25 oC mm2/S 70.6
Flash point oC 245
Pour point oC -3
C % 78.0
H % 12.0
N % 0.9
S % ND
O % 10.1
SIMDIST analysis
IBP oC 528
5 % oC 563
50 % oC 641
90 % oC 656
FBP oC 714

Further catalyst to maintain active sulfidic form UCO mixed with Dimethyl disulfide (DMDS) as a source of Sulfur which existed total amount of Sulfur maintain 2000 ppm.

Example 8 Reaction and Results
The ratio of prepared catalyst with respect to the Trijet catalyst is 1:3. The ratio of prepared catalyst and trijet catalyst was loaded beneath the bed of the Trijet catalyst (Figure 1).

It then undergoes a sulfidation process at 350°C for 20 hours before application of the said hydrogenation catalyst for producing the Sustainable Aviation Fuel (SAF), or the Green Diesel (GD), and wherein, the feedstock is used cooking oil with Oxygen content of 12.5%.
The optimum reaction conditions for producing Sustainable Aviation Fuel (SAF) are 420°C temperature, 60 bar Pressure, 1 WHSV, H2/feed ratio 1000 Nm3/m3.
Table 3. Product characterization
Catalyst CO (moles) Gasoline (IBP-130 °C) SAF
(130-260 °C) Diesel
(260-FBP)
Trijet catalyst without CO reduced catalyst 1.8 5 vol% 37 vol% 55 vol%
Trijet catalyst with Example 1 < 0.1 8 vol% 48 vol% 45 vol%

Example 9 Comparison of catalysts activity and durability study
Various catalysts including Trijet catalyst were evaluated and compared over a period of up to 120 hours. The evaluation involved measuring CO conversion using Used Cooking Oil (UCO) as a feedstock with a boiling point below 715°C and a sulfur content of 2000 ppm. The reactor operated at a pressure of 60 bar, an H2/feed ratio of 1000 Nm3/m3, and a WHSV of 1.

From the analysis it is evident that Example 1 exhibited superior activity and stability compared to comparative example 5. And the findings are presented in figure 2. , Claims:1. A catalyst for in-situ CO reduction in biofuel production, the catalyst comprising:
a) a porous catalyst carrier support selected from the group comprising Al2O3, SiO2-A12O3, CeO2-Al2O3, MgO2-Al2O3, ZrO2-Al2O3, and combinations thereof, in an amount of 50% to 80%;
b) a metal selected from the group comprising Ni, Mo, P and combinations thereof, in an amount of 20 % to 30% ; and
c) acidic peptizing agent along with pseudoboehmite in an amount of 15 % to 25 %.

2. The catalyst as claimed in claim 1, wherein the ratio of carrier support silicon dioxide- Aluminium oxide is 4:6, wherein the ratio of catalytic carrier support to metal to pseudoboehmite is 55:25:20.

3. The catalyst as claimed in claim 1, wherein the catalyst has a total surface area of 193.4 (m2/g), a total pore volume of 0.562 (cc/g), and an average pore radius of 70.6 (Å).

4. A method for preparing a catalyst for reduced production of CO in a biofuel production, the method comprising steps:
a) preparing a catalytic carrier support; and
b) impregnating the catalytic carrier support with a metal solution.

5. The method as claimed in claim 4, wherein the preparation of catalytic carrier support comprises:
i. mixing a carrier material with carrier precursor to obtain a mixture;
ii. stirring the mixture obtained in step i) at 300 rpm to 400 rpm at a temperature of 50 ºC to 70 ºC;
iii. adding sodium carbonate to the mixture obtained in step ii) to maintain pH at 7.5 to 8.5;
iv. cooling the mixture obtained in step iii) to obtain a precipitate;
v. washing the precipitate obtained in step iv);
vi. drying the precipitate obtained in step v) at 80 °C to 100 °C for 10 hours to 14 hours; and
vii. calcining the dried precipitate obtained in step vi) at 400 oC to 600 °C for 3 hours to 5 hours to obtain catalytic carrier support.

6. The method as claimed in claim 4, wherein the impregnation of the catalytic carrier support with a metal solution comprises:
i. mixing metal with precursor of 20 % to 30 % and organic acid in 400 g to 600 g of distilled water to prepare a homogeneous NiMoP solution;
ii. injecting the NiMoP solution into the catalytic carrier support;
iii. incubating the mixture at room temperature for 30 minutes to 120 minutes at temperature from 20 ? to 50 ?;
iv. evaporating the mixture obtained in step iii) to obtain a powdered mixture;
v. drying the powdered mixture obtained in step iv) at 100 °C to 150 °C for 10 hours to 14 hours;
vi. calcinating the dried mixture obtained in step v) at 400 °C to 600 °C for 2 hours to 6 hours to obtain calcinated powder;
vii. blending the calcined powder obtained in step vi) with an acidic peptizing agent and pseudoboehmite to obtain a paste;
viii. extruding the paste to obtain an extrudate;
ix. drying the extrudate at 120 °C; and
x. calcinating the dried extrudate at 400 oC to 600 °C for 2 hours to 6 hours to obtain a catalyst.

7. The method as claimed in claim 5, wherein the organic acid is selected from citric acid, hydroxycitric acid, itaconic acid, mesaconic acid, citraconic acid, aconitic acid, hibiscus acid, glutamic acid, nitrilotriacetic acid, ethylene diamino tetraacetic acid, 1,2-diaminopropane-N,N,N,N -tetraacetic acid, cyclohexane-1,2 diamine tetraacetic acid.

8. A method for in-situ CO reduction in biofuel production, the method comprising:

mixing of feedstock with sulfur source to maintain a total sulfur concentration of 2000 ppm, wherein the sulfur source is Dimethyl disulfide (DMDS);

subjecting the feedstock to sulfidation process at 350°C for 20 hours; and

loading catalyst as defined in claim 1 - 3, beneath the bed of trijet catalyst in a ratio 1:3 to obtain CO-reduced fuels.

9. The method as claimed in claim 8, wherein the fuel is Sustainable Aviation Fuel (SAF) or Green Diesel (GD).

10. The method as claimed in claim 8, wherein the feedstock is selected from used cooking oil (UCO), palm oil, jatropha oil, karanja oil, sunflower oil, cottonseed oil, soybean oil, mustard oil, coconut oil, rapeseed oil, tall oil.