DESC:FIELD OF THE INVENTION
The present invention relates to a simple and cost effective process of making hydrotreating catalyst from biomass using Group VI B and Group VIII metals in presence of a surface modifying chemical reagent. The catalytic metals have been deposited on the carbonized biomass, and the resulting formation have high BET surface area along with generation of micro and meso pores suitable for allowing larger size molecules for reaction to happen. The catalyst of the present invention is found to be useful for hydrotreating of vegetable oil, bio-oil, crude oil, petroleum or coal derived gas oil or blends thereof. Compared to existing hydrotreating catalyst preparation methods this invention provides a facile, high-yield and low-cost pathway to synthesis Ni-Mo hydrotreating catalyst.

BACKGROUND OF THE INVENTION
Hydrotreating catalysts are required to reduce heteroatoms like sulphur, nitrogen and even oxygen from feed fractions produced from crude oil to generate transportation fuel with acceptable fuel standards. To produce low sulphur diesel from high sulphur petroleum feeds, hydrotreating catalyst with mild acidity is generally preferred. Industrially, hydrotreating catalysts are prepared by incorporating metal salt solutions onto solid carrier supports such as alumina, silica, silica-alumina, silico-alumino phosphates, clays, zeolites, carbon nano tubes (CNT), charcoal, activated carbon (AC), etc. Catalytic elements coated on such carrier supports through different techniques are known in the art. Among all the supports, alumina is most widely used because of its thermal stability, mild acidity and low cost for hydrotreatment processes such as hydrodesulphurization, hydrodenitrogenation, hydrodearomatization and hydrodeoxygenation. However, alumina supports have limited pore size distribution for penetration of large size molecules and also coke formation on alumina support is another problem which shortens the catalyst life. For hydrotreatment of oxygen containing larger size molecules, such as vegetable oil, bio-oil, algal oil or their combination with gas oil or vacuum gas oil, catalyst with large pore diameter, high pore volume and high resistance towards coke formation is desirable. Therefore, to process larger size molecules, alternative catalyst supports with wide distribution of pores and less coke forming tendency are more preferable.
Activated carbon, being hydrophobic in nature, has been considered as a good catalyst support for hydrotreatment of oxygenated feeds. However, unlike naturally available refractory inorganic oxide supports, activated carbon is not naturally available. It can be produced from its precursor i.e., either from biomass, petroleum or coal via physical or chemical methods. Once prepared, the activated carbon shows excellent physical properties such as high surface area, pore volume with varying pore sizes which makes it a remarkable adsorbing agent for wider applications.
For bringing improved surface characteristics of activated carbon, chemical or physical activation methods are required which involves multiple steps that eventually increase the cost of production of activated carbon. Further, preparation of the catalyst from such activated carbon requires multiple steps along with high input of energy and cost. For preparing activated carbon from biomass, it is first converted into activated carbon either by chemical or physical process, followed by impregnation of metal salt and finally carbonization or calcination to make the catalyst. Therefore, the conventional catalyst preparation process from activated carbon is cost intensive. It is therefore, imperative to find an alternative method for making hydrotreating catalyst from low cost carbon precursor material with improved process of preparation. Among the carbon precursor material, spent tea is considered as having huge potential for making activated Carbon. Tea is consumed widely throughout the world as a beverage. During preparation of tea, the aroma of tea is extracted with hot water and the left over mass is directly rejected as waste with no use. Like other biomass residues, tea wastes represent an unused resource and pose increasing disposal problems. For these reasons, research studies are being carried out to evaluate their possible use as an energy source or in other value-added applications. One of the major routes is to convert this waste resource into activated carbon. Activated carbon has unlimited use as adsorbent for purification of waste water and industrial contaminants in water. Therefore, these renewable agricultural wastes such as spent tea are cost-effective alternatives to more expensive and polluting precursors like coal for the production of activated carbon and preparation of catalyst thereof. Apart from major use as an adsorbent and making activated carbon, there is no other major application associated with spent tea leaves.
From the above discussion, it is evident that with the growing cost and energy concerns associated with catalyst preparation by conventional methods for hydrotreating applications in order to produce more stringent fuel standards in terms of Sulphur, Nitrogen and Oxygen content, alternative processes are to be explored to prepare efficient hydrotreating catalyst in a relatively simple and cost effective manner.
The present invention addresses one or more such problems of the prior art as discussed above. However, it is contemplated that the invention may prove useful in addressing other problems also in a number of technical areas.

SUMMARY OF THE INVENTION
The present invention comprises a process of making a catalyst for hydrotreating of vegetable oil, gas oil or their blends into diesel. In one aspect of the invention, catalyst support precursor is any biomass and catalyst precursor is one or more elements selected from Group VIB and Group VIII. The other aspect of the invention is both catalyst and support precursors are mixed together along with one or more surface modifying inorganic reagents from Group IIIA or Group VA followed by curing at specified temperature and further carbonization or calcination in inert atmosphere at 500-700?C, thus the catalyst essentially is supported on activated carbon and having BET surface area of greater than 50 m2/g with average pore diameter greater than about 20 Å and average water pore volume greater than 0.3 cc/g.

More specifically, the present invention relates to a process for making a hydroprocessing catalyst comprising the steps of mixing a biomass and an inorganic reagent with an aqueous Group VIB and Group VIII metals to obtain a biomass metal composite; curing the biomass metal composite at a temperature in the range of 80 to 85 ºC to obtain a completely dried biomass-metal composite; carbonizing the dried biomass-metal composite to obtain a carbonized biomass-metal composite; hot water washing of the carbonized biomass-metal composite to obtain a hydroprocessing catalyst. The biomass is a fresh or spent carbonaceous material selected from the group comprising of any plant materials such as wood, plant leaves, seeds, stems and or a combinations thereof. The carbonaceous material used in the process is a fresh or spent tea leaves. Preferably, the carbonaceous precursor is spent tea leaves. The biomass has a surface area in the range of l-10 m2/g. The inorganic reagent is selected from Group IIIA or Group VA. Preferably, the inorganic reagent is a boron compound such as ortho boric acid (boric acid), boron trifluoride, boron tribromide, boric oxide, boron phosphate, boron nitride, boron carbide, etc. More preferably, the inorganic reagent is boric acid. The ratio of the biomass and the inorganic reagent is in the range of 1:1 to 1:0.0625 by weight.

The Group VI B metal is Molybdenum and Group VIII metal is Nickel or Cobalt or combinations thereof. The biomass and inorganic reagent is preheated and mixed well. Aqueous metal salt solutions are added stepwise first with Molybdenum salt solutions followed by Nickel or Cobalt solutions. The combined biomass-metal composite is cured at 80-85°C for 40-48 hrs. The dried biomass-metal composite mixture is carbonized at about 500-700°C. Carbonization can be carried out in glass vessel or any other metallic vessel. Preferably, the carbonization is carried out in glass vessel. The dried biomass-boric acid-metal composite is carbonized at 500-700°C. The carbonized metal composite is washed with hot water to get rid of residual boron compound. The metals were uniformly distributed over the carbonized biomass. The BET surface area of the hydroprocessing catalyst is in the range of 50-400m2/g. The pore diameter of the hydroprocessing catalyst is in the range of 12-300Å, wherein more than 50% of pores is in the range of about 20Å. The BET surface area of the inventive catalyst was found to be 150 m2/g.

In the above process, the inorganic reagent acts as a surface modifying agent. The inorganic reagent is completely removed from the hydroprocessing catalyst composition. The molybdenum in the hydroprocessing catalyst is in the range of 10- 15 wt%. The Nickel or Cobalt in the hydroprocessing catalyst is in the range of 0.5-5 wt%.

In one aspect of the invention, the hydroprocessing catalyst also contains phosphorous in the range of about 0.05-5 wt%. The presence of phosphorous in the hydroprocessing catalyst is attributed to its natural presence in tea leaves. The bulk density of the hydroprocessing catalyst is in the range of 0.2-0.6 g/ml. The bulk density of the catalyst is in the in the range of 0.4- 0.45 g/ml. The water pore volume of the hydroprocessing catalyst is in the range of 0.15-0.6 ml/g. For a person skilled in the art, it would be clear that water pore volume refers to the water occupying spaces and/or pores of activated carbon. Water pore volume gives an idea about the finished catalyst’s liquid hold up capacity. The water pore volume of the catalyst is in the range of 0.3- 0.5 ml/g. The carbon content of the hydroprocessing catalyst is in the range of 25-85 wt%. Preferably, the carbon content of hydroprocessing catalyst is in the range of 40-60 wt%.

In another aspect of the invention, the hydroprocessing catalyst also contains calcium, iron, magnesium and sodium. The presence of calcium, iron, magnesium and sodium is attributed to presence of these elements in tea leaves.

Another embodiment of the invention relates to a process for hydrotreating of vegetable oil, gas oil or pre-hydrotreating vacuum gas oil, bio-oil or combinations thereof or hydrotreating of any high sulphur and nitrogen containing feed prior to hydrocracking, isomerisation etc. to produce hydrocarbon products using catalyst composition as described above, comprising the steps of passing the feed and hydrogen mixture through the catalyst loaded in a micro-down flow reactor or batch reactor at a temperature in the range of 330-370 °C and at a pressure of 50-90 bar with a feed flow rate of about 0.l cc/min to 0.5 cc/minute and hydrogen to oil ratio of 300-700 Nm3/m3 and hydrogen flow of 2-6 SLPH. The catalyst for hydroconversion exists in the form of powder, pellets, monoliths, foams, granules or extrudates. The catalyst used for hydroconversion exists in granular form. The vegetable oil used in the process is Jatropha oil or Karanjia Oil. In the process for co-processing of petroleum oil used for co-processing as claimed in the above process, the said petroleum oil is gas oil, wherein the total sulfur content of feed is in the range of about 1-2wt%. Co-processing refers to a process where gas oil and vegetable oil is processed together. Gas oil and vegetable oil is mixed at certain ratio (1-20 wt% of vegetable oil and remaining part is gas oil) and the process of this combined feed for hydrotreating process is henceforth known as coprocessing.

The catalyst as described above is presulfided in-situ using DMDS in straight run gas oil as sulfiding agent. The catalyst used has surface area of about 10-400 m2/g, pore volume of about 0.2-0.4 ml/g, and average pore diameter of about 20 Å with bulk density of about 0.45-0.65 g/ml. The hydrotreated products of vegetable oil are in the diesel range components. The hydrotreated gas oil product has sulphur content less than about 50 ppm. The vegetable oil blended gas oil up to 20 wt% has sulphur content less than about 50 ppm and no oxygen. The conversion of vegetable oil is achieved 100%. The spent catalyst after the hydrotreating process was found to be very little coke content.

BRIEF DESCRIPTION OF THE DRAWINGS

Fig 1: XRD patterns used tea leaves (a), tea leaves with boric acid at 1:0.125 ratio after the calcination (b), tea leaves with metal salts with boric acid after calcination (c), tea leaves with metal salts (Ni-Mo) with boric acid after calcination in nitrogen followed by calcination in air at 350ºC (d), tea leaves with metal salts (Co-Mo) with boric acid after calcination in nitrogen followed by calcination in air at 350ºC (e).
Fig 2: FTIR spectra reflecting very strong Mo–O stretching vibrations detected in the 783–955 cm–1 range
Fig.3: Comparison of commercial method of making carbon supported catalysts and inventive catalyst.

DETAILED DESCRIPTION OF THE INVENTION
The present invention discloses a process for preparation of a hydrotreating catalyst, useful for removal of heteroatom such as sulphur, nitrogen and oxygen from crude oil, vegetable oil, bio oil or gas oil derived from coal or petroleum or their blends etc., the said catalyst is being prepared through a single step cost effective method from biomass where biomass is mixed with one or more inorganic reagent doped with metal salt solution and then carbonized to make the catalyst. The biomass support used in this invention could be a single biomass or mixtures of different fresh or spent biomass materials.
The biomass used for the purpose of the present invention can be obtained from various sources including but not limited to wood, coconut, grass, nutshell, lignin, plant leaves or any lignocellulosic type materials. An aspect of the invention discloses the novel use of spent tea leaves as biomass material for making hydrotreating catalyst. The spent tea leaves are available worldwide with no further commercial significance.
Since the spent tea leaves have very low surface area, it has very limited accessibility to hold metals on its surface. One embodiment of the present invention discloses a novel idea of using a Group IIIA or Group V element as a surface modifying agent which is invariably boric acid for improving the surface characteristics of the catalyst such as BET surface area and Iodine number. The boron compound used for the purpose includes but not limited to ortho boric acid, boron trioxide, boron triiodide, boron trifluoride, boron trichloride, boron nitride, boron carbide, etc., but preferably ortho boric acid. Nevertheless, the other chemical activating reagents including phosphoric acid, ZnCl2, KOH, etc. can also be used in addition to boron compounds to enhance the surface characteristics, but due to their toxicity and problems associated with disposal, their usage is not environmental friendly.
Metals used in accordance with the present invention include, but not limited to Group VIB and Group VIII metals, most preferably Nickel and Molybdenum. The molybdenum salts used for the purpose includes but not limited to ammonium hepta molybdate, phosphomolybdic acid, etc., but preferably ammonium hepta molybdate. The nickel salts used for the purpose includes nickel nitrate hexahydrate, nickel sulphate, nickel oxalate, nickel chloride, nickel phosphate etc., and most preferably Nickel Nitrate.
Other important aspect of the invention discloses the preparation methodology of the hydrotreating catalyst which is relatively simpler and economical. The present invention involves a single step process for catalyst preparation from biomass as compared to the generally adopted multiple step processes where biomass is first converted into activated carbon and then the catalyst is prepared from such activated Carbon.
The preparation method according to the present invention comprises, mixing of the biomass (tea leaves) with the boric acid which is pretreated at 80-85?C. The ratio of biomass and boric acid ranges from 1:1 to 1:0.0625 by weight. The aqueous metal salt solution is then added in a sequential manner to the mixture with continuous stirring for at least 30 minutes. The mixture obtained is dried in oven at 80-85?C for at least 48 hrs. The dried mass is heated at high temperature 500-700?C, preferably upto 500?C in inert atmosphere. The carbonized mass was washed several times with hot distilled water and then dried in air oven between 80 to 100?C to obtain the final catalyst. As one of the embodiment of the invention, the addition of boric acid is employed in order to increase the pore size and BET surface area of the catalyst during carbonization process of the biomass-metal salt mixture. The boric acid acts as swelling agent in the decomposition of the tea leaves which helps to create voids which leads to formation of micro and meso pores and also simultaneously metal oxides are very well dispersed on the carbonized tea leaves. The surface characteristics and physical-chemical properties of the catalyst developed are analyzed in terms of BET Surface area by N2 adsorption-desorption isotherm, XRD, XRF, TEM, TGA, Particle size, Water pore volume and Iodine Number. The catalyst prepared by this process shows excellent physical properties including high surface area, pore volume and varying pore sizes.
Boron or phosphorous or in combination of both are generally added in small quantity for making hydrotreating catalyst in order to increase the activity of the catalyst [(US20120037540), (Journal of catalysis vol 97, issue 2 357-365, 1986)]. In contrast to literature information, boron in this invention is used to increase the BET surface area of the catalyst. According to the invention, after carbonization of the biomass and metal salt composite, the resultant material was washed with hot distilled water till the pH of the filtrate reaches around 6-7. During that process, it has been found that the remains of any unreacted boric acid as well as the oxides of boron formed was washed away during hot water washing. The water washed catalyst sample obtained was analyzed in Inductively Coupled Plasma (ICP) and found that the catalyst does not contain Boron. The aim of adding boric acid to biomass was to increase the BET surface area of the final catalyst. After carbonization of the biomass-metal composite, water washing is required in order to remove all the residual boron compounds. The BET surface area of the final catalyst was not improved if hot water washing for carbonized biomass was not performed. No literature information is available mentioning application of boric acid use for increasing BET surface area of the catalyst prepared from biomass. But utilization of boron in improving activity of hydrotreating catalyst has been cited in literatures along with another inorganic element preferably phosphorous (Ind. Eng. Chem. Res., 2009, 48 (3), pp 1190–1195, CA2758285 A1). Interestingly, phosphorous was also identified in the inventive catalyst which was present in the tea leaves as part of its elemental composition and according to the literature information phosphorous is added additionally in the commercial catalyst in order to increase the catalyst activity. The phosphorous naturally present in the tea leaves is an additional advantage in making of catalyst from tea leaves which eliminate the step of adding phosphorous during catalyst preparation. The elemental composition of the final catalyst is shown below.

Table 1: Elemental composition of the final catalyst
Elements % wt/wt
Molybdenum 12.5
Nickel 0.5
Phosphorous 0.48
Calcium 0.66
Magnesium 0.08
Sodium 0.05
Iron 0.077
Boron Nil
Sulphur Nil
Carbon 53
Oxygen 27.5
Nitrogen 5

The addition of boron in this invention was used only to increase the BET surface area of the final catalyst.
Further advantage of the present invention is that sulphur is not present in the final catalyst as can be seen from CHNS analysis shown in Table 2 below for spent tea leaves, carbonized tea leaves and the inventive catalyst.
Table 2: CHGS analysis for spent tea leaves, carbonised tea leaves and the present catalyst
Wt% Carbon Hydrogen Nitrogen Sulphur
Spent tea leaves 44.7 6 3.1 0.7
Carbonized tea leaves 66.7 1.5 3.5 0.2
Inventive catalyst 52.4 2.1 5.06 0.0

The invention also discloses the application of catalyst prepared from such a preparation method for hydrotreatment of feed stock such as Vegetable oil, Gas Oil, or Vacuum gas oil or mixtures thereof by treating the said feedstock with the catalyst in presence of hydrogen. In an embodiment of the present invention, the invented catalyst has been used for co-processing of the blend of Jatropha Oil in Gas Oil. In another embodiment of the invention, the catalyst has been used for hydrotreatment of neat vegetable oil to produce high quality diesel. The catalyst has shown high stability and activity for hydrotreating of oxygenated compounds.
The process for the preparation of the catalyst according to the present invention is less expensive in comparison to the known technologies. Since the catalyst preparation represents reduced process steps and less energy consumption, the cost of preparation of the catalyst is lesser. Moreover, the inventive catalyst is prepared from spent biomass material which further makes the overall catalyst cost lower than the conventional catalyst prepared from alumina or any other inorganic oxide support.
The catalyst thus prepared from biomass offers the advantage of being non exhaustive since it is derived from renewable source. Another important advantage offered through this invention is the exploitation of the spent tea leaves which is available in abundance and otherwise rejected as waste. One embodiment of the present invention is the use of boric acid as chemical reagent for improving the surface characteristics of the catalyst. When catalyst is prepared from biomass without chemical reagent, it does not yield desired surface properties for carrying out hydrotreating reactions.
In comparison to other chemical activating agent generally employed (Zinc chloride, Potassium hydroxide, phosphoric acid, etc.) for preparing activated carbon from biomass, this invention utilizes boric acid which is environmental friendly reagent in comparison to the other chemical activating agents. Thus this invention provides an eco friendly route for catalyst preparation. Also the valuable metallic elements doped in the biomass support can be easily and completely recovered after use by simply burning of the catalyst.
Having described the basic aspects of the present invention, the following non-limiting examples illustrate specific embodiment thereof. According to this invention Ni-Mo and Co-Mo catalyst was prepared on tea leaves with and without boric acid. In order to compare the performance of the catalyst Ni-Mo catalyst was also prepared using commercial activated carbon as catalyst support. Also, the performance of the catalyst prepared on tea leaves was also compared with Commercial Ni-Mo on alumina. The Ni-Mo and Co-Mo prepared on tea leaves using boric acid is referred as Catalyst A and B respectively and the Ni-Mo catalyst prepared using commercial activated carbon support is referred as Catalyst C and commercial Ni-Mo based catalyst on Alumina support is referred as Catalyst D and Ni-Mo catalyst prepared on tea leaves without boric acid is referred as Catalyst E. The descriptions of these catalysts are mentioned below for clarity.
i. Catalyst A-Ni-Mo/tea leaves using boric acid
ii. Catalyst B-Co-Mo/tea leaves using boric acid
iii. Catalyst C-Ni-Mo/Commercial Activated Carbon
iv. Catalyst D-Commercial Ni-Mo/Al2O3
v. Catalyst E-Ni-Mo/tea leaves without boric acid

Preparation of Catalyst A
In an example of the present invention the catalyst was prepared using used tea leaves as catalyst support. Tea leaves were first washed with tap water and dried in oven at 100-120°C till free from moisture. The average particle size of the tea leaves is in the range of 100 to 1000 µm. Solid boric acid powder was added to tea leaves to form a mixture which was kept in oven at 80-85°C for 2-4 hrs. The ratio of biomass and boric acid was adjusted to 1:0.25 (wt/wt). Calculated amount of the aqueous ammonium heptamolybdate and aqueous nickel nitrate hexahydrate were added to the mixture in a sequential manner with continuous stirring. The resultant combined mixture was kept in oven at 80-85°C with heating rate of about 0.3?C/minute for 40-48 hrs. The dried mixture was stirred and then gradually heated from room temperature to 500-700°C in an inert atmosphere The mixture was kept at 500-700°C for about 10-20 minutes and gradually cooled down to room temperature. The mass thus obtained was washed repeatedly with hot distilled water. The catalyst was then dried in oven at 80-85°C for 2 hrs. The catalyst thus prepared is referred as Catalyst A.

Preparation of Catalyst B
Similar to preparation of Catalyst A as described above, in place of Nickel salt, cobalt salts such as cobalt chloride, cobalt acetate, cobalt sulphate, cobalt carbonate, cobalt octoate etc. may be used. Preferably, Cobalt Nitrate hexahydrate was used. The Co-Mo Catalyst thus prepared on tea leaves is referred as Catalyst B.

Preparation of Catalyst C
Activated carbon (AC) in extrudated form having a BET surface area of about 1100 m2/g was used. Molybdenum source i.e. Phosphomolybdic acid dissolved in distilled water was added to carbon support. This mixture was slowly stirred for 0.5-1 hr at room temperature. Aqueous solution of Nickel nitrate hexahydrate was added to the mixture and stirring continued slowly for 10- 12 hrs. The resultant solution was slowly evaporated on a hot plate at 80-85°C with heating rate of 0.3?C/minute and kept in an oven for 10-12 hrs at a temperature of 100-110°C with heating rate of about 0.3?C/minute. Subsequently, the material was taken in platinum crucible covered with lid, calcined at 500-700°C for 1-3 hr in an inert atmosphere. The resultant material was kept in muffle furnace at 300-350°C for 2-3 hrs to obtain the final catalyst. This catalyst is referred as Catalyst C.

Catalyst D
This catalyst is a commercial Ni-Mo on alumina supported catalyst and has been sourced internally.

Preparation of Catalyst E
Crushed tea leaves were mixed with Nickel salt and Molybdenum salt using sufficient quantity of distilled water and made into paste like form and kept in oven at 80-85ºC for 40-48 hrs. The dried mass was carbonized at 500-700?C in inert atmosphere followed by hot water washing. This catalyst is referred as Catalyst E.
The physico-chemical characteristics of Catalyst A, C and E are shown in Table 3. Table 3 has shown that BET surface area and Iodine number of Catalyst A was found to be higher than catalyst prepared from tea leaves without boric acid (Catalyst E). One of the active phases formed in the inventive catalyst is alkaline earth metal molybdate such as CaMoO4 (calcium molybdate) on activated carbon support. Metal molybdate are found useful as catalysts, optical fibers and scientillators. etc. Since the inventive catalyst was prepared from spent tea leaves it contains significant amount of elements such as calcium, iron, sodium, magnesium, etc. Among the elements, calcium has been found more which is already present in the support before catalytic elements such as Molybdenum and Nickel is doped. The peak of CaMoO4 formed in the catalyst is therefore assumed that calcium present in the biomass during carbonization react with Molybdenum salt forms CaMoO4, hence it is assumed that CaMoO4 is also assumed as one of the active phase present in the catalyst. It has also been found that the sharp peak of CaMoO4 formed after calcination was kept further in oven at 350 ºC for 1 hr and the XRD spectra this has shown no peak which shows that the active phases of the catalyst have been completely dispersed but it shows only the crystalline peak of silica (SiO2) and small amount of calcium carbonate (CaCO3). XRD spectra of, Ni-Mo/Co-Mo catalyst prepared on tea leaves are shown in Fig. 1. FTIR data revealed very strong Mo–O stretching vibrations detected in the 783–955 cm–1 range [Fig. 2]. FT-IR and XRD also confirms the presence of CaCO3 in the final catalyst sample which reveal that calcium in the tea leaves during carbonization partly react with oxygen and carbon forming CaCO3.

Table3: Physico- chemical Properties of Catalyst A, C and E
Properties Catalyst A Catalyst C Catalyst E
Support used Used Tea leaves Commercial AC Used Tea leaves
BET surface Area of support(m2/g) 2 1130 2
Iodine Number,
of support(mg/g) 140 1036 140
Boric acid employed or not Yes No No
Active metals used Ni-Mo Ni-Mo Ni-Mo
BET surface of the Catalyst, (m2/g) 150 230 24
Iodine Number of the catalyst
(mg/g) 595 740 295

Generally, for making any hydrotreating catalyst, the BET surface area of the support should be in the range of 200-300 m2/g in the case of alumina and in the range of 100-2000 m2/g in the case of activated carbon. [Ref US 5,624,547, EP0696633A1]. In contrast to high surface area support chosen for making hydrotreating catalyst, neat biomass with BET surface area of 2 m2/g was used as support for metal loading. Generally, higher the surface area of the support, higher is the possibility of metal loading. The increase in BET surface area observed for the inventive catalyst is attributed to the incorporation of boric acid which acts as a surface modifying chemical agent whereas catalyst prepared without use of boric acid has no increase in BET surface area, thus incorporation of boric acid is a new concept adopted in this invention, further the use of boric acid for increasing BET surface area of catalyst prepared on biomass has not been reported anywhere. XRD spectra of the inventive catalyst have shown that the Ni-Mo species were fully dispersed like commercial hydrotreating catalysts. One of the important aspect of the invention is that the catalyst is directly prepared from biomass without converting biomass into activated carbon. Generally, any biomass is first converted into activated carbon by chemical or physical method followed by metal doping and carbonization thus involves higher cost whereas the inventive step adopted in this invention did not require the compulsory step of converting biomass into activated carbon and the catalyst prepared in this way has improved BET surface area and uniform dispersion of active metals.
Performance evaluation of the Catalysts: The catalysts thus prepared was evaluated in pilot plant with different feed stocks: hydrotreating of neat gas oil (Case-I), blends of 20% Jatropha in gas oil (Case-II), neat Jatropha oil (Case-III) and 20% Karanjia in gas oil (Case-IV). The catalyst thus prepared was presulfided in situ using DMDS (Dimethyl disulphide) dissolved in Straight run gas oil using standard method of sulphiding.
Case-I: Hydrotreating of neat gas oil: (Reaction Conditions: Temperature-370ºC, H2 Pressure 90 bar, Gas to Oil ratio 500 Nm3/m3, Feed flow rate 0.117 cc/minute, H2 flow rate 3.5SLPH)
Properties
Feed Gas Oil Hydrotreated gas Oil

Catalyst A Catalyst C Catalyst D
Density 0.8448 0.8288 0.8236 0.8148

Sulphur, ppm 13,600 30 30 25

D-86 (Vol. Vs ?C

50 %

95 % 289

363

281

357
275

354
273

353

Diesel hydrotreating catalyst is particularly used for the removal of the predominant heteroatoms such as sulphur and nitrogen in the gas oil feed along with aromatic saturation. The inventive catalyst’s sulphur reduction efficiency as shown in case I prove the fact that that catalyst prepared from tea leaves as catalyst support has comparable hydrotreating catalytic activity with catalyst prepared from commercial activated carbon and alumina.

Case-II: Hydrotreating of 20% Jatropha in gas oil (Reaction Conditions: Temperature-370 ºC, H2 Pressure 90 bar, Gas to Oil ratio 500 Nm3/m3, Feed flow rate 0.117 cc/minute, H2 flow rate 3.5SLPH)
20% Jatropha in Gas Oil

Hydrotreated 20% Jatropha in Gas Oil

Properties
Catalyst A Catalyst C Catalyst D
Density 0.8651 0.8217 0.8236 0.8248

Sulphur, ppm 10,200 25 30 25

Atmospheric Distillation ASTM D-86 (Vol. Vs ?C)

50 %

95 % 286

369 283

367 284

369

Catalysts, particularly hydrotreating catalysts are generally used for gas oil desulphurization in order to produce EURO –IV fuels, but they are not very well established for feeds containing high amount of oxygen. In this invention, in order to establish the viability of commercial application, carbon based catalyst has been developed to process both high sulphur and high oxygen feed. The inventive catalyst has shown complete removal of oxygen and also sulphur reduction to 25 ppm for feed which contains 20% Jatropha oil in gas oil, thus proves the fact that simulataneous elimination of sulphur and oxygen can be achieved which is found to be at par with commercial catalyst.

Case-III: Hydrotreating of neat Jatropha Oil (Reaction Conditions: Temperature- 370 ºC, H2 Pressure 90 bar, Gas to Oil ratio 500 Nm3/m3, Feed flow rate 0.117 cc/minute, H2 flow rate 3.5SLPH)

Neat Jatropha Oil

Hydrotreated Neat Jatropha Oil

Properties
Catalyst A Catalyst C Catalyst D
Density 0.9204 0.7980 0.7988 0.7983

Sulphur, ppm Nil Nil Nil Nil

Atmospheric DistillationD-86 (Vol. Vs ?C)
CAT-A CAT-C CAT-D50% 287 284 283

95% 360 355 356

Further to prove the efficiency of the catalyst towards hydrodeoxygenation of vegetable oil, Jatropha oil as a model compound was studied. The products formed were found mostly in the diesel boiling range, therefore the selectivity of the catalyst is found at par with the commercial carbon and alumina supported Ni-Mo Catalysts.

Case-IV: Hydrotreating of 20% Karanjia in gas Oil using Catalyst A (Reaction Conditions: Temperature-370 ºC, H2 Pressure 90 bar, Gas to Oil ratio 500 Nm3/m3, Feed flow rate 0.117 cc/minute, H2 flow rate 3.5SLPH)
20% Karanjia in gas Oil Hydrotreated 20% Karanjia in gas Oil.Properties
Catalyst A
Density 0.8611 0.7980

Sulphur, ppm 9300 Nil

Atmospheric Distillation D-86 (Vol. Vs ?C)
50 %

95 % 285

367

Further in support of the inventive catalyst activity towards co-processing of Vegetable oil other than Jatropha Oil , 20% Karanjia oil in gas oil was further studied and found the activity is similar to the results obtained for 20% Jatropha in gas oil feed, thus confirms the hydrodeoxygenation and hydrodesulphurisation activity of the catalyst.

The performance of the catalyst prepared through the present single step cost effective method was found to be at par with the conventional Catalyst prepared from the Commercial alumina and activated carbon support.
To prepare catalyst from activated carbon, finished activated carbon with high surface area is required. Activated carbon as catalyst support has been very well established in literatures, but in view of the high cost and energy associated with its preparation, there has been a constant search for reduction cost associated with its preparation. The source for activated carbon is mainly two precursors namely biomass and coal or coke. As such charcoal derived from biomass does not have sufficient BET surface area and pore characteristics. To improve the surface characteristics of charcoal or coal physical or chemical treatment methods are adopted. Therefore, to prepare activated carbon it is essential to convert biomass into activated carbon. This activated carbon is used to make the catalyst. Therefore the process involves multiple thermal treatment steps first conversion of biomass into charcoal then impregnation of chemical reagent followed by thermal treatment after that the prepared activated carbon is impregnated with metals followed by thermal treatment again, therefore the process of preparing hydrotreating catalyst from biomass involves multiple step. The schematic representation of catalyst preparation is shown in Fig. 3. In order to overcome these multiple steps, a single step preparation procedure is adopted in this invention. The process involves direct doping of catalytic precursors in presence of an inorganic reagent followed by thermal treatment and the process is depicted in Fig. 3.
Thus the catalyst prepared directly from biomass has shown high hydrotreating activity for both gas oil and coprocessing of vegetable oil in gas oil feed and the results are found at par with the commercial alumina and commercial carbon supported catalysts and is less prone to carbonaceous deposits.
,CLAIMS:We Claim:
1. A process for making a hydroprocessing catalyst comprising the steps of:
(a) mixing a biomass and an inorganic reagent with an aqueous Group VIB and Group VIII metals to obtain a biomass metal composite;
(b) curing the biomass metal composite at a temperature in the range of 80 to 85 ºC to obtain a dried biomass-metal composite;
(c) carbonizing the dried biomass-metal composite to obtain a carbonized biomass-metal composite;
(d) hot water washing of the carbonized biomass-metal composite to obtain a hydroprocessing catalyst.

2. The process according to claim 1, wherein the biomass is a fresh or spent carbonaceous material selected from the group comprising of wood, plant leaves, seeds, stems and a combination thereof.

3. The process according to claim 2, wherein the carbonaceous material is fresh or spent tea leaves.

4. The process according to claim 3, wherein the carbonaceous material is spent tea leaves.

5. The process according to claim 1, wherein the biomass has a surface area in the range of l-10 m2/g.

6. The process according to claim 1, wherein the inorganic reagent is selected from Group IIIA or Group VA.

7. The process according to claim 6, wherein the inorganic reagent is boron compound selected from the group comprising ortho boric acid (boric acid), boron trifluoride, boron tribromide, boric oxide, boron phosphate, boron nitride, boron carbide.

8. The process according to claim 6, wherein the inorganic reagent is ortho boric acid.

9. The process according to claim 1, wherein the ratio of the biomass and the inorganic reagent is in the range of 1:1-1:0.0625.
10. The process according to claim 1, wherein the Group VI B metal is Molybdenum and Group VIII metal is Nickel or Cobalt or combinations thereof.

11. The process according to claim 1, wherein the biomass and inorganic reagent is preheated at 85?C.

12. The process according to claim 10, wherein aqueous metal salt solutions are added stepwise first with Molybdenum salt solutions followed by Nickel or Cobalt solutions.

13. The process according to claim 1, wherein the combined biomass-metal composite is cured at 80-85°C for 40-48 hrs.

14. The process according to claim 1, wherein the carbonisation of dried biomass-metal composite mixture is carried out at a range of 500-700°C.

15. The process according to claim 14, wherein the carbonization can be carried out in glass vessel or any other metallic vessel.

16. The process according to claim 14, wherein the carbonisation of the dried biomass-boric acid-metal composite is carried out at 500°C.

17. The process according to claim 14, wherein the carbonised biomass has uniform distribution of the metals over the carbonized biomass.

18. The process according to claim 1, wherein the BET surface area of the hydroprocessing catalyst is in the range of about 50-400m2/g.

19. The process according claim 1, wherein the pore diameter of the hydroprocessing catalyst is in the range of about 12 -300 Å.

20. The process according to claim 1, wherein more than about 50% of pores is in the range of 20 Å.

21. The process according to claim 18, wherein the BET surface area of the hydroprocessing catalyst is 150 m2/g.

22. The process according to claim 1, wherein complete removal of the inorganic reagent is carried out from the hydroprocessing catalyst composition.

23. The process according to claim 12, wherein the molybdenum in the hydroprocessing catalyst is in the range of 10- 15 wt%.

24. The process according to claim 12, wherein the Nickel or Cobalt in the hydroprocessing catalyst is in the range of 0.5-5 wt%.

25. The process according to claim 1, wherein the hydroprocessing catalyst also contains phosphorous in the range of 0.05-5 wt%.

26. The process according to claim 1, wherein the bulk density of the hydroprocessing catalyst is in the range of 0.2-0.6 g/ml.

27. The process according to claim 1, wherein the bulk density of the catalyst is 0.45 g/ml.

28. The process according to claim 1, wherein the water pore volume of the hydroprocessing catalyst is in the range of 0.15-0.6 ml/g.

29. The process according to claim 28, wherein the water pore volume of the catalyst is 0.3- ml/g.

30. The process according to claim 1, wherein the carbon content of the hydroprocessing catalyst is in the range of 25-85 wt%.

31. The process according to claim l, wherein the carbon content of hydroprocessing catalyst is in the range of 40-60 wt%.

32. The process according to claim 1, wherein the hydroprocessing catalyst also contains calcium, iron, magnesium and sodium.

33. A process for hydrotreating of vegetable oil, gas oil or pre-hydrotreating vacuum gas oil or any high sulphur and nitrogen containing feed prior to hydrocracking, or bio-oil or combinations thereof to produce hydrocarbon products using catalyst composition according to claim 1 comprising passing the feed and hydrogen mixture through the catalyst loaded in a micro-down flow reactor or batch reactor at a temperature in the range of 330-370°C and at a pressure of 50-90 bar with a feed flow rate of 0.l cc/min to 0.5 cc/minute and hydrogen to oil ratio of 300-700 Nm3/m3 and Hydrogen flow of 2-6 SLPH.

34. The process according to claim 33, wherein the catalyst for hydroconversion exist in the form of powder, pellets, monoliths, foams, granules or extrudates.

35. The process according to claim 33, wherein the catalyst used for hydroconversion is used in granular form.

36. The process according to claim 33, wherein the said vegetable oil is Jatropha oil or Karanjia Oil.

37. The process according to 33 wherein the said petroleum oil is gas oil.

38. The process according to claim 33, wherein the catalyst used has surface area of 50-400m2/g, pore volume of 0.2-0.4 ml/g, and average pore diameter of 20 Å with bulk density of 0.45-0.6g/ml.