CLIAMS:1. A process for conversion of a feedstock to crude bio-oil; said process comprising the following steps:
a. providing slurry comprising 5 to 50 % of the feedstock and 50 to 55 % water; and
b. hydrothermal liquefying the feedstock present using metal nano-particles at a temperature ranging from 200 to 400 oC and at a pressure ranging from 100 to 220 bars to obtain crude bio-oil.

2. The process as claimed in claim 1, wherein the metal nano-particles are generated in-situ by mixing a metal salt and the slurry and aging at a temperature ranging from 50 to 100 oC for 0.5 to 3 hours.

3. The process as claimed in claim 1, wherein the metal nano-particles are prepared separately using a metal salt; and the amount of metal nano-particle ranges from 0.1 to 10 wt%.

4. The process as claimed in claim 1, wherein the feedstock is at least one algae selected from the group of divisions consisting of Rhodophyta, Chlorophyta, Phaeophyta, Chrsophyta, Cryptophyta, Dinophyta, Tribophyta, Glaucophyta, Charophyta, Ochrophyta, Protista and Blue green algae (Cyanobacteria).

5. The process as claimed in claim 1, wherein the feedstock is at least one algae selected from the group consisting of Spirulina, Nannochloropsis, Chlorella, Euglena, Microcystis, Dictyosphaerium Anabaena, Nodularia, Oscillatoria, filamentous, Spirogyra, hydrodictyon, Chara, Nitella, Oedognium and Phormidium.

6. The process as claimed in claims 2 and 3, wherein the metal salt is at least one compound selected from the group consisting of transition metal compounds and noble metal compounds.
7. The process as claimed in claim 6, wherein the transition metal in the transition metal compound is at least one metal selected from the group consisting of nickel, molybdenum, cobalt, silver, gold, niobium and the noble metal noble metal compound is at least one metal selected from the group consisting of platinum, palladium, ruthenium and rhodium.

8. The process as claimed in claims 2 and 3, wherein the metal salts are oxides or salts of at least one metal selected from the group consisting of nickel, molybdenum, cobalt, silver, gold, niobium platinum, palladium, ruthenium and rhodium.

9. The process as claimed in claims 2 and 3, wherein the metal salt further comprise at least one support selected from the group consisting of silica, alumina, zirconia, zeolite, mesoporous and nano porous; said support being in the form selected from the group consisting of extrudates, spheres, pellets and powder; and said metal salt is in the form selected from the group consisting of extrudates, spheres, pellets and powder.

10. The process as claimed in claim 1, wherein the yield of crude bio-oil ranges from 45 to 80% and the carbon content of crude bio-oil ranges from 60-85%. ,TagSPECI:FIELD:
The present disclosure relates to a process for obtaining crude bio-oil from a feedstock.
BACKGROUND:
DEFINITIONS:
The term “feedstock” in the context of the present disclosure includes but is not limited to micro-algae, macro-algae, lipid containing bio-mass, algal bio-mass, bio-mass from wastes such as municipal waste, bio-refinery waste, food processing waste, animal waste, industrial waste, organic waste, urban refuse, wood, agricultural crops or wastes and the like, which can be used as a source of fuel or energy.
The term “crude bio-oil” in the context of the present disclosure includes but is not limited to petroleum crude containing at least one organic product such as free fatty acids, nitrogen containing heterocyclic compounds, polycyclic aromatics, unsaturated compounds and other heavier organic compounds.
Resources of natural fuel are about to be exhausted and therefore a suitable alternative needs to be provided. Bio-fuel is one of the most promising alternatives to the natural fuel. Out of the various ways to obtain bio-fuel, hydrothermal liquefaction (HTL) of a feedstock is the preferred way as the feedstock is available abundantly.
Various processes or methods have been suggested to convert a feedstock into bio-fuel, some using catalysts as the conversion of feedstock into bio-fuel in the absence of catalysts is as low as 40 %.
For example, WO2011126383 suggests a natural or synthetic clay catalyst or an aluminosilicate catalyst for obtaining organic chemical products from a feedstock of algal biomass or lipid-containing biomass.
WO2011126382 suggests a metal or a semi-metal oxide or a base catalyst for obtaining organic chemical products from a feedstock of algal biomass or lipid-containing biomass.
CN102021048 suggests a zeolite molecular sieve such as Y-type zeolite, USY-type zeolite, HZSM-5-type zeolite, ZSM-5 type zeolite, REUSY l type zeolite, REUSY 2 type zeolite and SiO2-Al2O3 catalyst for producing bio-fuel from bio-mass.
CN102002381 suggests a mordenite catalyst having particle size in the range of 0.1 to 5 mm for producing bio-fuel form algae.
CN102407161 suggests a complex of a transition metal and ionic liquid catalyst for hydrothermal liquefaction of bio-mass. The transition metal is nickel, iron or cobalt and the source of the transition metal is corresponding sulfate or nitrate compound.
CN100551562 suggests a nano catalyst of zirconium salts such as ZrOCl2, Zr(NO3)4, Zr(SO4)2 for the liquefaction of bio-mass.
CN101270296 suggests alkaline or alkaline earth metal salts such as hydrochloride, carbonate, bicarbonate salts of potassium, sodium and calcium for the liquefaction of bio-mass into bio-fuel or bio-oil.
Some of the catalysts suggested for the purpose of the conversion of the feedstock into a crude bio-oil need to be prepared separately before employing for the purpose, while others does not produce desired yield of a crude bio-oil.
Therefore, there is a felt need for a catalyst that does not require any pre-processing and is capable of converting the feedstock into bio-fuel in high yield.
OBJECTS:
Some of the objects of the present disclosure, which at least one embodiment herein satisfies, are as follows:
An object of the present disclosure is to provide a process for the conversion of a feedstock into crude bio-oil.
Another object of the present disclosure is to provide a process for the conversion of a feedstock into crude bio-oil in relatively high yield.
Still another object of the present disclosure is to provide a process for the conversion of a feedstock into crude bio-oil in which the catalyst is generated in-situ.
Still another object of the present disclosure is to provide a process for the conversion of a feedstock into crude bio-oil having relatively high carbon content.
Other objects and advantages of the present disclosure will be more apparent from the following description and drawings which are not intended to limit the scope of the present disclosure.
SUMMARY:
The present disclosure provides a process for the conversion of a feedstock into crude bio-oil. The process of conversion is hydrothermal liquefaction in which the feedstock is converted into crude bio-oil with simultaneous removal of water using metal nano-particles as a catalyst. A metal salt is in-situ converted into metal nano-particles with the help of the feedstock, whereas the formed metal nano-particles enhance the conversion of the feedstock into crude bio-oil. The metal salt used for the purpose of the present invention is at least one selected from the group of compounds consisting of oxides and salts of transition metal compounds or noble metal compounds or both.
DETAILED DESCRIPTION:
The present disclosure provides a process for conversion of a feedstock to crude bio-oil. The process is described herein after.
In the first step, slurry comprising 5 to 50 % of feedstock and 50 to 55 % water is provided. To the slurry a metal salt is added and aged at a temperature in the range of 50 to 100 oC for 0.5 to 3 hours to obtain an aged mass containing metal nano-particles. The aged mass is subjected to hydrothermal liquefaction to obtain crude bio-oil. The hydrothermal liquefaction is carried out by using in-situ generated metal nano-particles at a temperature ranging from 200 to 400 oC and at a pressure ranging from 100 to 220 bars. Alternatively, metal nano-particles can be prepared separately i.e., ex-situ preparation, added to the slurry for hydrothermal liquefaction of the feedstock. Examples of metal salts from which the metal nano-particles are generated during liquefaction process include but are not limited to transition metal compounds and noble metal compounds. Examples of transition metal compound include oxides or salts of at least one metal selected from the group consisting of nickel, molybdenum, cobalt, silver, gold and niobium, whereas the examples of the noble metal compounds include oxides or salts of at least one metal selected from the group consisting of platinum, palladium, ruthenium and rhodium.
Type of nano-particles obtained during in-situ generation of nano-particles or ex-situ preparation is based on the type of the metal salt used. For example, if rhodium chloride is used as a metal salt then the nano-particles generated are nano-particles of rhodium. Accordingly, the metal in the metal nano-particle is at least one transition metal and/or noble metal. Examples of transition metal include, nickel, molybdenum, cobalt, silver, gold, niobium, whereas the examples of noble metal include platinum, palladium, ruthenium and rhodium.
The transition metal compounds and the noble metal compounds can additionally comprise a support. Further, the transition metal compounds and the noble metal compounds can be in the form selected from the group consisting of extrudates, spheres, pellets and powder.
Examples of the support used for transition metal compounds and the noble metal compounds include but are not limited to silica, alumina, zirconia, zeolite, mesoporous and nano porous. The support can be in the form selected from the group consisting of extrudates, spheres, pellets and powder.
The amount of metal nano-particle required for the effective conversion of feedstock to crude bio-oil ranges from 0.1 to 10 wt%. Accordingly, the amount of the metal salt can be taken at the start of the reaction or the preparation of the nano-particles.
Though the yield of crude bio-oil and the carbon content in crude bio-oil depends on various factors such as type of a feedstock, parameters employed and metal salt or metal nano-particles used, the yield of crude bio-oil is observed to be in the range of 45 to 80% and the carbon content ranges from 60-85%.
The feedstock useful for the purpose of the present disclosure is at least one algae selected from the group of divisions consisting of Rhodophyta, Chlorophyta, Phaeophyta, Chrsophyta, Cryptophyta, Dinophyta, Tribophyta, Glaucophyta, Charophyta, Ochrophyta, Protista and Blue green algae (Cyanobacteria).
Particularly, the feedstock is at least one algae selected from the group consisting of Spirulina, Nannochloropsis, Chlorella, Euglena, Microcystis, Dictyosphaerium Anabaena, Nodularia, Oscillatoria, filamentous, Spirogyra, hydrodictyon, Chara, Nitella, Oedognium and Phormidium.

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

Catalytic Hydrothermal Liquefaction

Feedstock as 20% slurry in water was loaded in a reactor. 1 wt. % of metal salt was added to the reactor. The reactor was then closed and aged at 80 oC for 1 hour during which metal nano-particles were generated. 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. The results are provided in table 1

Table 1: Crude Bio-Oil yield data using various metal nano-particles and feedstock
Sr. No. Metal Nanoparticle Algae Species CBO Yield, %
1 Absent Spirulina 48
2 Absent Nannochloropsis 57
3 Silver Nannochloropsis 64
4 Silver Spirulina 54
5 Platinum Spirulina 54
6 Rhodium Spirulina 55
7 Rhodium Nannochloropsis 63
8 Copper Spirulina 55
9 Ruthenium Spirulina 58

From the above table it is seen that process of the present disclosure which involves the use of metal nano-particles as a catalyst yields higher crude bio-oil as compared to a process in which catalyst is absent.
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.
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.
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.
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.
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.