Catalyst composition and a catalytic process for conversion of biomass to crude bio oil

Abstract

The present disclosure provides a catalyst composition for conversion of biomass to crude bio oil. The composition comprises at least one metal compound, at least one support and at least one stabilizing/solubilizing agent. Also disclosed are processes for the preparation of catalyst composition, and hydrothermal conversion of biomass to crude bio oil.

Claims

1. A process for the preparation of a catalyst composition having at least one metal in an amount of 0.1 to 15 wt. %; and at least one support in an amount of 30 to 96 wt %, said process comprising the following steps: a. obtaining at least one support selected from the group consisting of alumina, silica, zirconia, alumina-silica, zeolite and molecular sieves; b. preparing at least one dispersion containing at least one metal or metal compound and at least one solvent, said metal compound comprises a metal selected from the group consisting of group IB metals, group IIB metals, group IVB metals, group VB metals, group VIB metals, group VIIB metals, group VIII metals and noble metals; c. adding a solubilizing agent to one or more of said at least one dispersion/s wherein said solubilizing agent is hexamethyleneimine; d. obtaining a mixture of said at least one dispersion, wherein said one or more of said at least one dispersion/s comprises said solubilizing agent; e. impregnating said mixture in said support to obtain a metal impregnated support; f. drying the metal impregnated support followed by calcining to obtain a calcined metal impregnated support; and g. reducing the calcined metal impregnated support in the presence of hydrogen at a temperature un the range 400 C. to 600 C. to obtain the catalyst.

2. The process as claimed in claim 1, wherein the method step (c) comprises a step of mixing at least two dispersions, each containing at least one metal or metal compound before the addition of said solubilizing agent.

3. The process as claimed in claim 1, wherein the solvent for preparing said at least one dispersion is selected from the group consisting of polar solvents and non-polar solvents.

4. The process as claimed in claim 1, wherein the step of obtaining a support includes the steps of mixing at least one carrier; at least one binder selected from the group consisting of aluminophosphate, pseudoboehmite, silica, alumina, and ludox silica solution; at least one agent selected from the group consisting of peptizing agent, pH adjusting agent and template directing agent; and optionally, at least one liquid medium; in any order to obtain a dough, obtaining extrudates from said dough, drying said extrudates and calcining said dried extrudates, wherein, the peptizing agent is at least one selected from the group consisting of phosphoric acid and acetic acid; the pH adjusting agent is at least one compound selected from the group consisting of nitric acid, ammonium hydroxide and trimethylammonium hydroxide; the template directing agent is at least one selected from the group consisting of pluronic 123 and cetyltrimethylammonium bromide; and the liquid medium is at least one selected from the group consisting of water and ethyl alcohol.

5. The process as claimed in claim 1, wherein said support comprises a) 30 to 100 wt % at least one carrier selected from the group consisting of alumina, silica, zirconia, alumina-silica, zeolite and molecular sieves; and b) 0.001 to 70 wt % of at least one binder selected from the group consisting of aluminophosphate, pseudoboehmite, alumina, silica and ludox silica solution.

6. The process as claimed in claim 1, wherein said support comprises a) 30 to 100 wt % at least one carrier selected from the group consisting of nano-structured aluminum oxide, nano-structured silicon oxide, nano-structured zirconium oxide, nano-structured cerium oxide, nano-structured titanium oxide, nano-structured tantalum oxide; and b) 0.001 to 70 wt % of at least one binder selected from the group consisting of aluminophosphate, pseudoboehmite, alumina, silica and ludox silica solution.

7. The process as claimed in claim 1, wherein said support comprises a) 30 to 100 wt % at least one carrier selected from the group consisting of mesoporous alumino silicate, mesoporous silicate, mesoporous molecular sieves; and b) 0.001 to 70 wt % of at least one binder selected from the group consisting of aluminophosphate, pseudoboehmite, alumina, silica and ludox silica solution.

8. The process as claimed in claim 1, wherein the metal is selected from the group consisting of nickel (Ni), molybdenum (Mo), cobalt (Co), copper (Cu), silver (Ag), zinc (Zn), zirconium (Zr), vanadium (V), tungsten (W), rhenium (Re), platinum (Pt), palladium (Pd),ruthenium (Ru) and rhodium (Rh); and the metal compound comprises a cation selected from the group consisting of nickel (Ni), molybdenum (Mo), cobalt (Co), zinc (Zn), zirconium (Zr), vanadium (V), tungsten (W), rhenium (Re), platinum (Pt), palladium (Pd), ruthenium (Ru) and rhodium (Rh); and an anion selected from the group consisting of chlorides, bromides, fluorides, iodides, sulfates, phosphates, phosphonates, nitrates, nitrites, carbonates, acetates, acetylacetates, acetylacetonates, bicarbonates, hydroxides and oxides.

Description

BRIEF DESCRIPTION OF ACCOMPANYING DRAWINGS

(1) FIG. 1 illustrates XRD of CoMo/Al2O3 catalyst;

(2) FIG. 2 illustrates XRD of NiMo/Al2O3 catalyst;

(3) FIG. 3 illustrates XRD of CoMo/ZrO2 catalyst;

(4) FIG. 4 illustrates GCMS chromatogram of crude bio oil; and

(5) FIG. 5 illustrates a process for the preparation of crude bio oil.

DETAILED DESCRIPTION

(6) Considering the drawbacks associated with known hydrothermal liquefaction methods for the conversion of biomass to crude bio oil, such as time consumption, energy consumption and low yield, the inventors of the present disclosure focused on improving the hydrothermal liquefaction method. The inventors of the present disclosure found that the hydrothermal conversion of biomass such as algae can be efficiently carried out in the presence of a catalyst composition. It is further found that a specific catalyst composition plays a crucial role in producing quality crude bio oil. It is particularly found that the use of a strong base such as piperidine, pyrrolidine, morpholine, piperazine hydrate, 2-methylcyclohexyl amine, cyclohexylamine and hexamethyleneimine in the synthesis of the catalyst composition provides solubilizing effect on the metal salts and results in metal complex formation resulting in enhanced metal impregnation in support. This in turn helps in stabilization of the catalyst composition on supports such as a metal oxide support. The inventors surprisingly found that this catalyst system efficiently performs the catalytic reaction and produces crude bio oil from biomass.

(7) Accordingly, the present disclosure provides a catalyst composition for conversion of biomass to crude bio oil. The composition mainly contains at least one metal in an amount of 0.1 to 15 wt. %, at least one support in an amount of 30 to 96 wt %, and at least one solubilizing agent in an amount of 4 to 50 wt. %.

(8) The support present in the catalyst composition is selected from the group consisting of alumina, silica, zirconia, alumina-silica, zeolite and molecular sieves.

(9) The support present in the catalyst composition in one embodiment comprises a) 30 to 100 wt % at least one carrier selected from the group consisting of alumina, silica, zirconia, alumina-silica, zeolite and molecular sieves; b) 0.001 to 70 wt % of at least one binder.

(10) The support present in the catalyst composition in another embodiment comprise a) 30 to 100 wt % at least one carrier selected from the group consisting of nano-structured aluminum oxide, nano-structured silicon oxide, nano-structured zirconium oxide, nano-structured cerium oxide, nano-structured titanium oxide, nano-structured tantalum oxide; b) 0.001 to 70 wt % of at least one binder.

(11) The support present in the catalyst composition in yet another embodiment comprise a) 30 to 100 wt % at least one carrier selected from the group consisting of mesoporous alumino silicate, mesoporous silicalite, mesoporous molecular sieves; b) 0.001 to 70 wt % of at least one binder.

(12) Examples of binder useful for the purpose of the present invention include aluminum oxide, aluminophosphate, psuedoboehmite, silica and ludox silica solution.

(13) It is to be noted here that though the support is prepared using peptizing agent is used, during the preparation of the support, the peptizing agent does not remain in the support due to calcination. Therefore, the peptizing agent is also absent in the catalyst composition.

(14) In an exemplary embodiment, the support used in the catalyst composition of the present disclosure is in the form of extrudates, spheres, or pellets. The length of the extrudate ranges from 4 to 6 mm, diameter of the extrudate ranges from 1 to 2 mm and surface area ranges from 25 to 1000 m.sup.2/gm. The diameter of sphere and pellets ranges from 3 to 10 mm, respectively.

(15) The metal in the catalyst composition includes but is not limited to group Ib metals, group IIb metals, group IVb metals, group Vb metals, group VIb metals, group VIIb metals, group VIII metals and noble metals. Particularly, the metal is selected from the group consisting nickel (Ni), molybdenum (Mo), cobalt (Co), copper (Cu), silver (Ag), zinc (Zn), zirconium (Zr), vanadium (V), tungsten (W), rhenium (Re), platinum (Pt), palladium (Pd), ruthenium (Ru) and rhodium (Rh).

(16) The metal compound useful to introduce the metal contains a cation which includes but is not limited to nickel (Ni), molybdenum (Mo), cobalt (Co), copper (Cu), silver (Ag), zinc (Zn), zirconium (Zr), vanadium (V), tungsten (W), rhenium (Re), platinum (Pt), palladium (Pd), ruthenium (Ru) and rhodium (Rh); and an anion which includes but is not limited to chlorides, bromides, fluorides, iodides, sulfates, phosphates, phosphonates, nitrates, nitrites, carbonates, acetates, acetylacetate, acetylacetonate, bicarbonates, hydroxides and oxides.

(17) The solubilizing agent employed in the catalyst composition of the present disclosure is selected from the group consisting of piperidine, pyrrolidine, morpholine, piperazine hydrate, 2-methylcyclohexyl amine, cyclohexylamine and hexamethyleneimine. Preferably, the solubilizing agent is hexamethyleneimine.

(18) The catalyst composition of the present disclosure is mainly characterized by the following: total acid strength ranging from 0.05 to 3.5 mmole/gm of ammonia; and pore width ranging from 1 to 20 nm.

(19) Further, the support used in the catalyst composition has a surface area ranging from 25 to 1000 m.sup.2/gm.

(20) The present disclosure also provides a simple process for preparing the catalyst composition which can be carried out at room temperature.

(21) The process involves the following steps:

(22) In the first step, a support is obtained.

(23) Separately, at least one dispersion containing at least one metal or metal compound and at least one solvent is prepared.

(24) In the next step, at least one solubilizing agent is added to one or more of the at least one dispersion/s. Then a mixture of the at least one dispersion, wherein the one or more of the at least one dispersion/s comprises said at least one solubilizing agent is prepared.

(25) In another embodiment, a step of mixing at least two dispersions containing at least one metal or metal compound before the addition of at least one solubilizing agent is carried out, i.e. at least two dispersions each containing at least one metal or metal compound are mixed to obtain a mass/complex and to this mass at least one solubilizing agent is added to obtain a mixture.

(26) In another exemplary embodiment, molybdenum dispersion in water is prepared by adding ammonium molybdate in water. Due to its properties molybdenum remains un-dissolved in water. To dissolve molybdenum, hexamethyleneimine (HMI) is added to the dispersion to obtain a dispersion in which molybdenum is dissolved in water. Separately, a dispersion in which nickel is dissolved in water is prepared and mixed with the dispersion in which molybdenum is dissolved in water. HMI present in the molybdenum dispersion also stabilizes the complex of molybdenum and cobalt.

(27) In the next step, the obtained mixture is impregnated in the support to obtain a metal impregnated support which is then dried, calcined and reduced to obtain the catalyst composition.

(28) In the context of the present disclosure the term dispersion means a metal or metal compound either dissolved or undissolved in a solvent. Not all metal compounds are soluble in a solvent but they can be solubilized by adding a solubilizing agent. Therefore, in case of metal compounds insoluble in the solvent, a suspension containing the metal compound and the solvent is obtained before the addition of the solubilizing agent. After the addition of the solubilizing agent the suspension is converted into dispersion where the metal compound is dispersed in the solvent.

(29) In accordance with the present disclosure the solvent for preparing the at least one dispersion is selected from the group consisting of polar solvents and non-polar solvents.

(30) In one exemplary embodiment, at least one dispersion is prepared by mixing at least one metal or metal compound, at least one solubilizing agent selected from the group consisting of piperidine, pyrrolidine, morpholine, piperazine hydrate, 2-methylcyclohexyl amine, cyclohexylamine and hexamethyleneimine, and at least one solvent selected from the group consisting of polar solvents and non-polar solvents.

(31) In another exemplary embodiment, a first metal dispersion (e.g., of Co) and a second metal dispersion (e.g., of Ni) are prepared separately and mixed together to obtain a mixture. To this mixture a solubilizing agent is added. The solubilizing agent (HMI) also acts as a stabilizing agent for stabilizing the complex of cobalt and nickel.

(32) In one embodiment of the present disclosure, the metal or metal compounds in dispersions are different.

(33) In accordance with the present disclosure the step of preparing a metal dispersion is carried out at a temperature of 20 to 80 C. for a time period of about 5 to 60 minutes.

(34) Further, the drying of metal impregnated carrier is carried out at a temperature of 80 to 150 C., whereas the calcining is carried out at a temperature of 500 to 700 C. in the presence of air and reduction is carried out at a temperature of 400 to 600 C. for a time period of about 1 to 6 hours in the presence of hydrogen.

(35) In accordance with one embodiment the catalyst composition of the present disclosure is a bi-metallic catalyst composition.

(36) The solubilizing agent is used for solubilizing at least one metal compound and for further stabilizing a metallic complex (e.g., a bi-metallic complex).

(37) The metal useful for the purpose of the present disclosure is selected from the group consisting of nickel (Ni), molybdenum (Mo), cobalt (Co), copper (Cu), silver (Ag), zinc (Zn), zirconium (Zr), vanadium (V), tungsten (W), rhenium (Re), platinum (Pt), palladium (Pd), ruthenium (Ru), rhodium (Rh) and combinations thereof.

(38) Alternately, the metal compound used in the preparation of the catalyst composition. The metal compound that provides said metal contains a cation selected from the group consisting of nickel (Ni), molybdenum (Mo), cobalt (Co), copper (Cu), silver (Ag), zinc (Zn), zirconium (Zr), vanadium (V), tungsten (W), rhenium (Re), platinum (Pt), palladium (Pd), ruthenium (Ru) and rhodium (Rh); and an anion selected from the group consisting of chlorides, bromides, fluorides, iodides, sulfates, phosphates, phosphonates, nitrates, nitrites, carbonates, acetates, acetylacetates, acetylacetonates, bicarbonates, hydroxides and oxides.

(39) The solubilizing agent used in the preparation of catalyst composition is selected from the group consisting of piperidine, pyrrolidine, morpholine, piperazine hydrate, 2-methylcyclohexyl amine, cyclohexylamine and hexamethyleneimine, preferably, hexamethyleneimine.

(40) In accordance with the present disclosure the step of preparing a support includes steps of mixing at least one carrier, at least one binder, at least one agent and optionally, at least one liquid medium to obtain dough. The dough is extruded to obtain extrudates which are then dried and calcined. In one embodiment, the drying of extrudate is carried out at room temperature for a time period of 10 to 180 minutes followed by at 80 to 130 C. for a time period of 2 to 8 hours. Typically, the calcining of extrudates is carried out at a temperature of 500 to 700 C. in the presence of air.

(41) The agents useful for the preparation of the support include but are not limited to peptizing agent such as phosphoric acid and acetic acid, pH adjusting agent such as nitric acid, ammonium hydroxide and trimethylammonium hydroxide, and template directing agent such as pluronic 123 and cetyltrimethylammonium bromide.

(42) The liquid medium useful in the preparation of the support includes but is not limited to water and ethyl alcohol.

(43) The support used in the preparation of the catalyst composition is selected from the group consisting of alumina, silica, zirconia, alumina-silica, zeolite and molecular sieves.

(44) Alternatively, the support used in the preparation of the catalyst composition comprises a) 30 to 100 wt % at least one carrier selected from the group consisting of alumina, silica, zirconia, alumina-silica, zeolite and molecular sieves; and b) 0.001 to 70 wt % of at least one binder.

(45) In another embodiment the support used for the preparation of the catalyst composition comprises a) 30 to 100 wt % at least one carrier selected from the group consisting of nano-structured aluminum oxide, nano-structured silicon oxide, nano-structured zirconium oxide, nano-structured cerium oxide, nano-structured titanium oxide, nano-structured tantalum oxide; and b) 0.001 to 70 wt % of at least one binder.

(46) In still another embodiment the support used for the preparation of the catalyst composition comprises a) 30 to 100 wt % at least one carrier selected from the group consisting of mesoporous alumino silicate, mesoporous silicalite, mesoporous molecular sieves; and b) 0.001 to 70 wt % of at least one binder.

(47) The binder employed in the preparation of the catalyst composition is at least one selected from the group consisting of aluminophosphate, psuedoboehmite, alumina oxide, silica and ludox silica solution.

(48) The present disclosure further provides a process for conversion of biomass to crude bio oil using the catalyst composition of the present disclosure. The process involves the following steps:

(49) In the first step, biomass slurry is prepared using processes known in the art. The concentration of the biomass in the slurry ranges from 5 to 35 wt. %. The biomass utilized includes but is not limited to organic waste, agricultural residues, urban refuse, land- and water-based plant material and microorganism. The biomass that can be used is at least one of high and low lipid containing species. Specifically, the biomass can be algae selected from the group of divisions consisting of Rhodophyta, Chlorophyta such as Chlorella, Dictyosphaerium, Spirogyra, hydrodictyon and Oedognium, Phaeophyta, Chrsophyta, Cryptophyta, Dinophyta, Tribophyta, Glaucophyta, Charophyta such as Chara and Nitella, Ochrophyta such as Nannochloropsis, Protista such as euglena and Blue green algae such as Spirulina, Microcystis, Anabaena, Nodularia, Oscillatoria, Phormidium and the like.

(50) In the next step, the catalyst composition of the present disclosure is added to the slurry to obtain a mixture. The amount of catalyst composition utilized ranges from 1 to 20 wt. % with respect to the biomass. The resulting mixture is then heated at a temperature ranging from 200 to 400 C. and at a pressure ranging from 70 to 250 bars for a time period ranging from 10 to 180 minutes to obtain the crude bio oil and a residue containing catalyst composition. Alternatively, the resulting mixture is heated in the presence of a hydrogen source such as hydrogen and/or methane.

(51) The process of the present disclosure further involves the steps which include but are not limited to stirring, cooling, washing, separating and concentrating.

(52) The yield of the crude bio oil according to the process of the present disclosure is found to be in the range of 45% to 80%. Further, the carbon content of the crude bio oil, obtained by the process of the present disclosure, is found to be in the range of 74 to 80%. It is also found after analysis that the crude bio oil contains free fatty acids, nitrogen containing heterocyclic compounds, monocyclic aromatic compounds, dicyclic aromatic compounds, polycyclic aromatic compounds, unsaturated aliphatic compounds, saturated aliphatic compounds, aliphatic and aromatic amino compounds, aliphatic and aromatic amide compounds.

(53) The present disclosure is further described in light of the following examples which are set forth for illustration purpose only and not to be construed for limiting the scope of the disclosure.

EXAMPLE 1

Preparation of a Catalyst Composition

(54) Solution A was prepared by dissolving cobalt acetate (0.863 gm) in water (10 ml) at 30 C. for 10 minutes. Separately, solution B was prepared by dissolving ammonium molybdate (10.41 gm) and hexamethyleneimine (7 gm) in water (70 ml) at 60 C. for 30 minutes at 300 rpm. Solution A and B were then mixed together at 30 C. To this alumina powder (10 gm) was added and mixed for 2 hours to obtain a mixture. The liquid from the mixture was discarded and the remaining mass was dried at room temperature for 2 hours. This mass was further dried at 120 C. for 10 hours and calcined at 600 C. for 6 hours. The resulting calcined mass was subjected to reduction in the presence of hydrogen at 500 C. for 4 hours to obtain the catalyst (CoMo/Al.sub.2O.sub.3).

EXAMPLE 1A (COMPARATIVE EXAMPLE)

(55) The process of example 1 was repeated except that 8 gm of ammonia solution (25%) was used instead of hexamethyleneimine (7 gm).

EXAMPLE 1B

(56) The process of example 1 was repeated except that 8 gm of cyclohexylamine was used instead of hexamethyleneimine (7 gm).

EXAMPLE 1C (COMPARATIVE EXAMPLE)

(57) The process of example 1 was repeated except that 8 gm of ammonia solution (25%) was used instead of hexamethyleneimine (7 gm) and zirconia powder was used instead of alumina extrudate.

EXAMPLE 1D

(58) The process of example 1 was repeated except that 8 gm of cyclohexylamine was used instead of hexamethyleneimine (7 gm) and zirconia powder was used instead of alumina extrudate.

EXAMPLE 1E

(59) The process of example 1 was repeated except that zirconia powder was used instead of alumina extrudate.

EXAMPLE 2

Preparation of a Catalyst Composition

(60) Solution A was prepared by dissolving nickel nitrate (1.011 gm) in water (10 ml) at 30 C. for 10 minutes. Separately, solution B was prepared by dissolving ammonium molybdate (10.41 gm) and hexamethyleneimine (7 gm) in water (70 ml) at 60 C. for 30 minutes at 300 rpm. Solution A and B were then mixed together at 30 C. To this alumina powder (10 gm) was added and mixed for 2 hours to obtain a mixture. The liquid from the mixture was discarded and the remaining mass was dried at room temperature for 2 hours. This mass was further dried at 120 C. for 10 hours and calcined at 600 C. for 6 hours. The resulting calcined mass was subjected to reduction in the presence of hydrogen at 500 C. for 4 hours to obtain the catalyst (NiMo/Al.sub.2O.sub.3).

EXAMPLE 2A (COMPARATIVE EXAMPLE)

(61) The process of example 2 was repeated except that 7 gm of ammonia solution (25%) was used instead of hexamethyleneimine (7 gm).

EXAMPLE 2B

(62) The process of example 2 was repeated except that 7 gm of cyclohexylamine was used instead of hexamethyleneimine (7 gm).

EXAMPLE 3

Preparation of Catalyst Composition

(63) Solution A was prepared by dissolving rhodium chloride (0.381 gm) and hexamethyleneimine (7 gm) in water (100 ml) at 30 C. for 30 minutes at 300 rpm. To this zirconia powder (10 gm) was added and mixed for 2 hours at 30 C. to obtain a mixture. The liquid from the mixture was discarded and the remaining mass was dried at room temperature for 2 hours. This mass was further dried at 120 C. for 10 hours and calcined at 600 C. for 6 hours. The resulting calcined mass was subjected to reduction in the presence of hydrogen at 500 C. for 4 hours to obtain the catalyst (Rh/zirconia).

EXAMPLE 4A

Catalytic Hydrothermal Liquefaction using Marine Microalgae, Nannochloropsis

(64) 21 g Nannochloropsis as 20% slurry in water was loaded in an HTHP reactor (capacity: 300 ml). 10 wt. % of powdered CoMo/Al.sub.2O.sub.3 catalyst (1.897 g w.r.t. ash and moisture free algae) of the present disclosure was added to the reactor. The reactor was then closed. Leak check was done using nitrogen at 120 bar. Nitrogen pressure was released and the required amount of hydrogen (35 bar) was filled and heated to reaction temperature (350 C.) with 500 rpm stirring speed. Upon reaching the temperature, the reactor was kept under the same condition for 30 min. It was then cooled with chilled water facility and the gas was collected for gas analysis. The reactor was opened and the product was collected in a beaker. Oil, aqueous and solid phases were separated and measured individually. The mixture was filtered using a Buckner flask. The obtained powder was washed with Dichloromethane and water and then dried. The liquids (oil and aqueous phase) were separated by solvent extraction method.

EXAMPLE 4B

Catalytic Hydrothermal Liquefaction using Chlorella

(65) 21 g chlorella as 20% slurry in water was loaded in an HTHP reactor (capacity: 300 ml). 10 wt. % of powdered CoMo/Al.sub.2O.sub.3 catalyst (1.897 g w.r.t. ash and moisture free algae) of the present disclosure was added to the reactor. The reactor was then closed. Leak check was done using nitrogen at 120 bar. Nitrogen pressure was released and the required amount of hydrogen (35 bar) was filled and heated to reaction temperature (350 C.) with 500 rpm stirring speed. Upon reaching the temperature, the reactor was kept under the same condition for 30 min. It was then cooled with chilled water facility and the gas was collected for gas analysis. The reactor was opened and the product was collected in a beaker. Oil, aqueous and solid phases were separated and measured individually. The mixture was filtered using a Buckner flask. The obtained powder was washed with Dichloromethane and water and then dried. The liquids (oil and aqueous phase) were separated by solvent extraction method.

EXAMPLE 5

(66) The process of example 4A and 4B was repeated using 10 wt. % of powdered NiMo/Al.sub.2O.sub.3 catalyst obtained in example 2.

EXAMPLE 6

(67) The process of example 4A and 4B was repeated using 10 wt. % of powdered Rh/ZrO.sub.2 catalyst obtained in example 3.

EXAMPLE 7

Catalytic Hydrothermal Liquefaction using Fresh Water Microalgae, Spirulina

(68) 23 g of Spirulina as 20% slurry in water loaded in a reactor (HTHP reactor, capacity: 300 ml). 10 wt. % of powdered CoMo/Al.sub.2O.sub.3 catalyst (1.897 g w.r.t. ash and moisture free algae) of the present disclosure was added to the reactor. The reactor was then closed. Leak check was done using nitrogen at 120 bar. The nitrogen pressure was released and the required amount of hydrogen (35 bar) was filled and heated to reaction temperature (350 C.) with 500 rpm stirring speed. Upon reaching the temperature, the reactor was kept under the same conditions for 30 min. It was then cooled with chilled water facility and the gas was collected for gas analysis. The reactor was opened and the product was collected in a beaker. Oil, aqueous and solid phases were separated and measured individually. The mixture was filtered using a Buckner flask. The powder was washed with Dichloromethane and water and dried. The liquids (Oil and aqueous phase) were separated by gravimetric method.

EXAMPLE 8

(69) The process of example 7 was repeated using 10 wt. % of powdered NiMo/Al.sub.2O.sub.3 obtained in example 2.

EXAMPLE 9

(70) The process of example 7 was repeated using 10 wt. % of powdered Rh/ZrO.sub.2 obtained in example 3.

(71) The comparative results of % HTL oil yield for conventional methods (without catalyst/with commercial catalysts) vis--vis catalysts of the present disclosure are provided in the Table No. 1:

(72) Yield (%) of HTL oil was calculated as weight of oil product100/weight of moisture and ash free algae in the HTL slurry.

(73) TABLE-US-00001 TABLE NO. 1 % Crude Bio Oil yield Catalysts Nannochloropsis Spirulina Chlorella Without catalyst 58 46 CoMo/Al.sub.2O.sub.3 (Commercial) 68 48 NiMo/Al.sub.2O.sub.3 (Commercial) 65 48 Present (CoMo/Al.sub.2O.sub.3 + 73 57 59 hexamethyleneimine) Example 1 Present (NiMo/Al.sub.2O.sub.3 + 69 55 56 hexamethyleneimine) Example 2 Present (Rh/ZrO.sub.2 + 71 55 45 hexamethyleneimine) Example 3 Present (CoMo/ZrO.sub.2 + 71 61 hexamethyleneimine) Example 1E Present (CoMo/Al.sub.2O.sub.3 + 63 51 49 25% ammonia solution) Example 1A Present (CoMo/Al.sub.2O.sub.3 + 60 50 50 cyclohexylamine) Example 1B Present (NiMo/Al.sub.2O.sub.3 + 25% 60 51 48 ammonia solution) Example 2A Present (NiMo/Al.sub.2O.sub.3 + 61 52 49 cyclohexylamine) Example 2B Present (CoMo/ZrO.sub.2 + 25% 63 ammonia solution) Example 1C Present (CoMo/ZrO.sub.2 + 61 cyclohexylamine) Example 1D

(74) From the results, it is clear that % HTL oil yield by the process of the present disclosure which utilizes a catalyst comprising a solubilizing agent is 48 to 73%. Whereas, the % HTL oil yield using the commercial catalyst (which is devoid of a solubilizing agent) ranges from 48 to 68%.

(75) It is particularly found that when a catalyst comprising hexamethyleneimine as a solubilizing agent is utilized for liquefaction of high lipid Nannochloropsis algae, % HTL oil yield is 69 to 73%. Thus, when hexamethyleneimine is used as a solubilizing agent, the process of the present disclosure provides high yield of crude bio oil than the crude bio oil yield obtained by the process which utilize commercial catalyst.

(76) The following examples illustrate preparation of the extruded form of the catalyst composition using extruded support which may be recycled and regenerated as per process of the present disclosure:

EXAMPLE-10

PREPARATION of SUPPORT

EXAMPLE 10

(77) A: Alumina Support Preparation (10 g Batch) Pseudoboehmite (4.0 g) and alumina (7.0 g) were taken. To this, 6 ml of diluted solution of orthophosphoric acid was mixed to obtain aluminophosphate gel. This gel was mixed in a mortar-pestle and pegged to extrudable dough.

(78) B: Alumina Support Preparation (10 g Batch) Pseudoboehmite (4.0 g) and alumina (7.0 g) were taken. To this, 7 ml of diluted solution of acetic acid was mixed to obtain aluminum acetate gel. This gel was mixed in a mortar-pestle and pegged to extrudable dough.

(79) C: Zirconia Support Preparation (10 g Batch) Zirconium hydroxide powder (14.0 g) and Pseudoboehmite alumina (4.0 g) were mixed. Diluted solution of orthophosphoric acid (6 ml) was added while mixing to prepare Zirconium phosphate gel. This gel was mixed in a mortar-pestle and pegged to extrudable dough.

(80) D: Zirconia Support Preparation (10 g Batch) Zirconium hydroxide powder (14.0 g) and Pseudoboehmite alumina (4.0 g) were mixed. Diluted solution of acetic acid (7 ml) was added while mixing to prepare Zirconium acetate gel. This gel was mixed in a mortar-pestle and pegged to extrudable dough.

(81) E: Zeolite Support Preparation (10 g Batch) To make zeolite extrudates, Pseudoboehmite alumina (4.0 g) and diluted solution of orthophosphoric acid (6 ml) were mixed thoroughly with a mixture of zeolite powder (7.0 g) and hydroxypropylmethyl cellulose (HPMC, 0.1 g) in a mortar-pestle and pegged to extrudable dough.

(82) Upon making the above said dough, it was passed through extruder/nodulizer and obtained extrudates like wires. It was then dried at room temperature for 2 hours followed by 120 C. for 6 hours. Finally, it was calcined at 540-600 C. in presence of air for 6 hours in an air flow.

EXAMPLE 11

(83) A]

Preparation of a Catalyst Composition

(84) Dispersion A was prepared by dissolving cobalt acetate (0.863 g) in water (10 ml) at 30 C. for 10 minutes. Separately, dispersion B was prepared by dissolving ammonium molybdate (10.41 g) and hexamethyleneimine (7 g) in water (70 ml) at 60 C. for 30 minutes at 300 rpm. Dispersions A and B were then mixed together at 30 C. To this alumina support of example 10 A (10 gm) was added and mixed for 2 hours to obtain a mixture. The liquid from the mixture was discarded and the remaining mass was dried at room temperature for 2 hours. This mass was further dried at 120 C. for 10 hours and calcined in presence of air at 600 C. for 6 hours. The resulting calcined mass was subjected to reduction in the presence of hydrogen at 500 C. for 4 hours to obtain the catalyst (CoMo/Al.sub.2O.sub.3).

B (COMPARATIVE EXAMPLE)

(85) The process of example 11A was repeated except that 8 g of ammonia solution (25%) was used instead of hexamethyleneimine (7 g).

(86) C] The process of example 11A was repeated except that 8 g of cyclohexylamine was used instead of hexamethyleneimine (7 g).

EXAMPLE 12

A](COMPARATIVE EXAMPLE)

(87) The process of example 11A was repeated except that 8 g of ammonia solution (25%) was used instead of hexamethyleneimine (7 g) and zirconia support of example 10C was used instead of alumina support.

(88) B] The process of example 11A was repeated except that 8 gm of cyclohexylamine was used instead of hexamethyleneimine (7 g) and zirconia support of example 10 C was used instead of alumina support.

(89) C] The process of example 11A was repeated except that zirconia support of 10D was used instead of alumina support. D] The process of example 11A was repeated except that Zeolite support of example 10 E was used instead of alumina support.

EXAMPLE 13

A] Preparation of a Catalyst Composition

(90) Dispersion A was prepared by dissolving nickel nitrate (1.011 g) in water (10 ml) at 30 C. for 10 minutes. Separately, dispersion B was prepared by dissolving ammonium molybdate (10.41 g) and hexamethyleneimine (7 g) in water (70 ml) at 60 C. for 30 minutes at 300 rpm. Dispersions A and B were then mixed together at 30 C. To this alumina support of example 10 A (10 g) was added and mixed for 2 hours to obtain a mixture. The liquid from the mixture was discarded and the remaining mass was dried at room temperature for 2 hours. This mass was further dried at 120 C. for 10 hours and calcined at 600 C. in presence of air for 6 hours. The resulting calcined mass was subjected to reduction in the presence of hydrogen at 500 C. for 4 hours to obtain the catalyst (NiMo/Al.sub.2O.sub.3).

B](COMPARATIVE EXAMPLE)

(91) The process of example 13A was repeated except that 7 g of ammonia solution (25%) was used instead of hexamethyleneimine (7 g).

(92) C] The process of example 13A was repeated except that 7 g of cyclohexylamine was used instead of hexamethyleneimine (7 g).

EXAMPLE 14

Preparation of Catalyst Composition

(93) Dispersion A was prepared by dissolving rhodium chloride (0.381 g) and hexamethyleneimine (7 g) in water (100 ml) at 30 C. for 30 minutes at 300 rpm. To this zirconia support obtained in 10 C (10 g) was added and mixed for 2 hours at 30 C. to obtain a mixture. The liquid from the mixture was discarded and the remaining mass was dried at room temperature for 2 hours. This mass was further dried at 120 C. for 10 hours and calcined in presence of air at 600 C. for 6 hours. The resulting calcined mass was subjected to reduction in the presence of hydrogen at 500 C. for 4 hours to obtain the catalyst (Rh/Zirconia).

EXAMPLE 15

Catalytic Hydrothermal Liquefaction using Marine Microalgae, Nannochloropsis

(94) 21 g Nannochloropsis as 20% slurry in water loaded in an HTHP reactor (capacity: 300 ml). 10 wt. % of extruded CoMo/Al.sub.2O.sub.3 catalyst, obtained in example 11A (1.897 g w.r.t. ash and moisture free algae) of the present disclosure was added to the reactor. The reactor was then closed. Leak check was done using nitrogen at 120 bar. Nitrogen pressure was released and the required amount of hydrogen (35 bar) was filled and heated to reaction temperature (350 C.) with 500 rpm stirring speed. Upon reaching the temperature, the reactor was kept under the same condition for 30 min. It was then cooled with chilled water facility and the gas was collected for gas analysis. The reactor was opened and the product was collected in a beaker. Oil, aqueous and solid phases were separated and measured individually. The mixture was filtered using a Buckner flask. The powder was washed with Dichloromethane and water and dried. The liquids (oil and aqueous phase) were separated by solvent extraction method.

EXAMPLE 16

(95) The process of example 15 was repeated using 10 wt. % of extruded NiMo/Al.sub.2O.sub.3 catalyst, obtained in example 13A.

EXAMPLE 17

(96) The process of example 15 was repeated using 10 wt. % of extruded Rh/ZrO.sub.2 catalyst obtained in example 14.

EXAMPLE 18

Catalytic Hydrothermal Liquefaction using Fresh Water Microalgae, Spirulina

(97) 23 g of Spirulina as 20% slurry in water was loaded in a reactor (HTHP reactor, capacity: 300 ml). 10 wt. % of extruded CoMo/Al.sub.2O.sub.3 catalyst, obtained in example 11A (1.897 g w.r.t. ash and moisture free algae) of the present disclosure was added to the reactor. The reactor was then closed. Leak check was done using nitrogen at 120 bar. The nitrogen pressure was released and the required amount of hydrogen (35 bar) was filled and heated to reaction temperature (350 C.) with 500 rpm stirring speed. Upon reaching the temperature, the reactor was kept under the same conditions for 30 min. It was then cooled with chilled water facility and the gas was collected for gas analysis. The reactor was opened and the product was collected in a beaker. Oil, aqueous and solid phases were separated and measured individually. The mixture was filtered using a Buckner flask. The powder was washed with Dichloromethane and water and dried. The liquids (Oil and aqueous phase) were separated by gravimetric method.

EXAMPLE 19

(98) The process of example 18 was repeated using 10 wt. % of extruded NiMo/Al.sub.2O.sub.3 obtained in example 13A.

EXAMPLE 20

(99) The process of example 18 was repeated using 10 wt. % of extruded Rh/ZrO.sub.2 obtained in example 14.

EXAMPLE 21

Recovery of the Catalyst

(100) The solid residue obtained in example 15 was subjected to sieving to separate the catalyst. The obtained catalyst was then subjected to calcination at 600 C. and then subjected to reduction in the presence of hydrogen at 500 C. to obtain a catalyst ready for recycle.

EXAMPLE 22

(101) The process of example 21 was repeated except that the solid residue obtained in example 16 was used.

EXAMPLE 23

(102) Recycling of the Catalyst

(103) The catalyst recovered as per example 21 was used for hydrothermal liquefaction of microalgae. The process of example 15 was repeated.

(104) The comparative results of % crude bio oil yield are provided in the table No. 2.

(105) TABLE-US-00002 TABLE 2 Crude Bio Oil Yield (%) Algae, Nannochloropsis Algae, Spirulina CoMo/ CoMo/ Al2O3 NiMo/Al2O3 Al2O3 NiMo/Al2O3 obtained in obtained in obtained in obtained in Runs example 11 example 13 example 11 example 13 Catalyst - 70 68 57 55 1(Fresh) 1st 69 68 57 56 Regeneration 2nd 70 67 58 57 Regeneration 3rd 68 69 56 55 Regeneration 4th 69 68 56 56 Regeneration 5th 70 68 57 55 Regeneration

(106) The comparative properties of the fresh and recovered catalyst are provided in table No. 3.

(107) TABLE-US-00003 TABLE 3 XRD Pore Pore NH3- TGA Sr. Catalyst (Crystal- BET, volume diameter TPD (% wt loss up- No. Name linity) m.sup.2/g (cc/g) () (mmol/g) to 900 C.) 1 Catalyst-1 Quasi 176 0.496 98 0.842 7.20 (Fresh), crystalline prepared as per example 11A 3 Catalyst-2 Quasi 170 0.479 101 0.813 9.55 (Regenerated), crystalline prepared as per example 21 4 Catalyst-3 Quasi 181 0.503 96 0.812 11.42 (Fresh) crystalline prepared as per example 13A 6 Catalyst-4 Quasi 165 0.455 100 0.805 9.28 (Regenerated) crystalline prepared as per example 22

(108) Yield (%) of crude bio oil was calculated as weight of oil product100/weight of moisture and ash free algae.

(109) From the results, it is clear that % crude bio oil yield by using the regenerated catalyst of the present disclosure is similar to that of fresh catalysts.

(110) The following examples illustrate preparation of the catalyst composition using nano-structured support of the present disclosure.

Preparation of Nano-Structured Support

EXAMPLE 24

(111) Solution A was prepared by dissolving 8 g of Pluronic-123 (poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide)) in 75 g of ethyl alcohol.

(112) Separately, Solution B was prepared by dissolving 16 g aluminum iso-propoxide (Al(OPri)3 in the mixture of 10 ml 60% nitric acid and 70 g ethyl alcohol.

(113) Solution B was added to Solution A with stirring. Stirring was continued for 4 h at room temperature. The resultant solution was kept in oven at 60 C. for 72 h for evaporation of, ethanol and for crystallization. The final powdered nano-structured aluminum oxide was further dried at 110 C. for 6 h. The nano-structured material was obtained by removing Pluronic-123 by calcining at 540 C. for 6 h under the flow of air.

(114) This calcined material was used as a support for the preparation of a catalyst composition by the process as described for examples 11-14.

EXAMPLE 25

(115) In-situ synthesis of mono or multi metallic catalysts of nano-structured aluminum oxide were synthesized by following the same method as described in Example 24. The required amounts of metal salts such as cobalt acetate or nickel acetate with ammonium molybdate, etc. were added during preparation of Solution B. After metal loading, samples were calcined at 540 C. in air and followed by reduced at 500 C. in H2.

EXAMPLE 26

(116) For the preparation of nano-structured zirconium oxide, Solution A was prepared by dissolving 7.5 g of Cetyltrimethylammonium bromide (CTAB) in 25 g of distilled water. Further, 0.5 g of trimethylammonium hydroxide (TMAOH) was added and stirred for 30 min. Solution B was prepared by mixing 53 g of 1-butanol with 33 g of 80% solution of zirconium (iv) butoxide. Solution B was added drop wise into solution A with vigorous stirring to obtain a gel. pH of the gel was adjusted to 10.5-11. Gel was stirred for 2 h at RT and then it was transferred to 500 ml round bottom flask and refluxed at 90 C. for 48 h to obtain nano-structured zirconium oxide was collected by filtration and washing using distilled water. Solid powder of nano-structured zirconium oxide was dried at 110 C. for 6 h and calcined at 600 C. for 6 h under the flow of air.

(117) This calcined material was used as catalyst support for the preparation of a catalyst composition by the process as described for examples 11-14.

EXAMPLE 27

(118) In-situ synthesis of mono or multi metallic catalysts of nano-structured zirconium oxide were synthesized by following the same method as described in Example 26. Metal salts such as cobalt acetate or nickel acetate with ammonium molybdate, etc. were prepared as solution C and added upon addition of solution B into solution A. After metals loading, samples were calcined at 540 C. in air and followed by reduced at 500 C. in H2.

(119) The catalysts synthesized in examples 24-27 were used for the conversion of Bio-mass to crude bio-oil as per the procedure described in example 4 for algal species Nannochloropsis and example 7 for algal species Spirulina. The results are depicted in Table 4

(120) TABLE-US-00004 TABLE 4 CBO yield from different algae species using various catalyst compositions CBO Catalyst Name Algae Species Yield, % No Catalyst Spirulina 48 CoMo/gamma Alumina Spirulina 57 CoMo/Nano-structured alumina Spirulina 56 (Example 24) In-situ CoMo/Nano-structured alumina Spirulina 60 (Example 25) CoMo/Nano-structured zirconia Spirulina 59 (Example 26) In-situ CoMo/Nano-structured zirconia Spirulina 62 (Example 27) No Catalyst Nannochloropsis 58 CoMo/gamma Alumina Nannochloropsis 68 CoMo/Nano-structured alumina Nannochloropsis 67 (Example 24) In-situ CoMo/Nano-structured alumina Nannochloropsis 70 (Example 25) CoMo/Nano-structured zirconia Nannochloropsis 65 (Example 26) In-situ CoMo/Nano-structured zirconium Nannochloropsis 68 oxide (Example 27) CoMo/Nano-structured zirconium oxide Nannochloropsis* 75 (Example 26) *Slurry concentration - 35%

(121) The following example illustrates preparation of the catalyst composition using mesoporous zeolite support of the present disclosure.

EXAMPLE 28

(122) For the preparation of meso-porous zeolite, Solution A was prepared using 6 g of Cetyltrimethylammonium bromide (CTAB) in 450 g of distilled water. Further, 28.5 ml of ammonium hydroxide (NH4OH) was added and stirred for 30 min. In the above solution, 8 g of zeolite power was added, stirred at room temperature for 20 min and then hydrothermally treated at 120-180 C. for 10-24 h. This was cooled, filtered and washed to obtain final meso-porous zeolite in the powder form. The powder was dried at 110 C. for 6 h and calcined at 600 C. for 6 h under the flow of air. This calcined material was used as catalyst composition by the process as described for examples 11-14

(123) The catalysts synthesized in examples 28 was used for the conversion of Bio-mass to crude bio-oil as per the procedure as per the procedure described in example 4 for algae species Nannochloropsis and example 7 for algae species Spirulina. The results are depicted in Table 5

(124) TABLE-US-00005 TABLE 5 CBO yield using various catalyst compositions Algae Catalyst CBO Yield, % Nannochloropsis No Catalyst 57 Nannochloropsis Neat Meso-porous Zeolite 61 Nannochloropsis CoMo/Meso-porous Zeolite 71 (Example 28) Spirulina No Catalyst 46 Spirulina Neat Mesoporous Zeolite 50 Spirulina CoMo/Mesoporous Zeolite 61 (Example 28)

(125) Technical Advance and Economic Significance: The present disclosure provides a method for the preparation of a catalyst at a room temperature having better catalytic activity. The catalyst mainly contains a solubilizing agent, particularly hexamethyleneimine (HMI) which exhibits better solubilizing effect on the catalyst metal salts and results in a metal complex formation, which in turn helps in stabilization of the catalyst metal on a metal oxide support. The present disclosure also provides a simple and high yielding process for the conversion, and specifically, hydrothermal conversion of biomass to crude bio oil. The process of the present disclosure involves heating the biomass only once at pre-determined temperature and pressure conditions, thus the process is time saving and energy efficient. The conversion process of the present disclosure can be carried out at sub-critical conditions of temperature and pressure to give higher yield of crude bio oil.

(126) Throughout this specification the word comprise, or variations such as comprises or comprising, will be understood to imply the inclusion of a stated element, integer or step, or group of elements, integers or steps, but not the exclusion of any other element, integer or step, or group of elements, integers or steps.

(127) The use of the expression at least or at least one suggests the use of one or more elements or ingredients or quantities, as the use may be in the embodiment of the disclosure to achieve one or more of the desired objects or results.

(128) Any discussion of documents, acts, materials, devices, articles or the like that has been included in this specification is solely for the purpose of providing a context for the disclosure. It is not to be taken as an admission that any or all of these matters form a part of the prior art base or were common general knowledge in the field relevant to the disclosure as it existed anywhere before the priority date of this application.

(129) The numerical values mentioned for the various physical parameters, dimensions or quantities are only approximations and it is envisaged that the values higher/lower than the numerical values assigned to the parameters, dimensions or quantities fall within the scope of the disclosure, unless there is a statement in the specification specific to the contrary.

(130) While considerable emphasis has been placed herein on the specific features of the preferred embodiment, it will be appreciated that many additional features can be added and that many changes can be made in the preferred embodiment without departing from the principles of the disclosure. These and other changes in the preferred embodiment of the disclosure will be apparent to those skilled in the art from the disclosure herein, whereby it is to be distinctly understood that the foregoing descriptive matter is to be interpreted merely as illustrative of the disclosure and not as a limitation.