FORM 2
THE PATENTS ACT 1970
[39 OF 1970]
&
THE PATENTS RULES, 2003
COMPLETE SPECIFICATION
[see section 10 and rule13]
“HYDROCARBON FUEL FROM POLYOLEFIN AND BIOMASS USING A NOVEL CATALYST”
Name and address of the Applicant: RELIANCE INDUSTRIES LIMITED
3rd Floor, Maker Chamber-IV, 222, Nariman Point, Mumbai-400 021, Maharashtra, India.
Nationality: Indian
The following specification particularly describes the invention and the manner in which it is to be performed.

FIELD OF THE INVENTION
[0001] The present disclosure relates to a single step process for converting polyolefin, optionally mixed with biomass, into hydrocarbon fuel using a novel transition metal-based catalyst. The present disclosure also relates to the novel catalyst.
BACKGROUND
[0002] It is estimated that approximately 70% of plastic packaging products are converted into plastic waste in a short span. Approximately 3.5 million tons per annum (TPA) plastic waste was generated in India in 2019-2020. Thus, waste management has become one of the biggest challenges while addressing environmental concerns. Conversion of these waste and non-recyclable low value products into high value product for end use applications is very tricky and necessary to avoid landfilling from plastic waste. Although there are studies on conversion of plastic waste into hydrocarbon-based fuel, there is still a need to develop new processes and new catalysts that can convert plastic waste or a combination of plastic waste and biomass into hydrocarbon fuel more effectively. There is also a need to provide a process and a catalyst that can convert plastic waste and waste biomass into hydrocarbon fuel that is low in sulphur and has more aliphatic content. The present disclosure attempts to address this need.
BRIEF SUMMARY
[0003] The present disclosure provides a process for producing hydrocarbon fuel, comprising: a) subjecting a feed comprising a polyolefin to pyrolysis at a temperature of 350°C-550°C in presence of a catalyst comprising Ni/Mo/Mg (OR)2; and b) subjecting vapors generated during pyrolysis to condensation to produce the hydrocarbon fuel. In some embodiments, the feed comprises polyolefin and biomass.

[0004] The present disclosure also provides a catalyst having a formula: Ni/Mo/Mg (OR)2, wherein the R group is selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, or pentyl.
[0005] The present disclosure further provides a hydrocarbon fuel, wherein the hydrocarbon fuel comprises C6-C24 carbon and has an aliphatic content of about 75–93 wt%.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0006] Figure 1 illustrates an exemplary set up of a pyrolysis reactor.
[0007] Figure 2 shows the GC-MS chromatogram of hydrocarbon fuel from the catalytic pyrolysis of polypropylene (Example 2).
[0008] Figure 3 shows the 13C NMR spectra of hydrocarbon fuel from the catalytic pyrolysis polypropylene (Example 2)
[0009] Figure 4 shows the GC-MS chromatogram of hydrocarbon oil from the catalytic pyrolysis of PP and sugarcane bagasse biomass (a) 20 % biomass (b) 40% biomass (c) 60% biomass (Example 3).
[0010] Figure 5 shows the 13C NMR spectra of hydrocarbon fuel oil obtained from polypropylene and sugarcane bagasse biomass (a) 20 % biomass (b) 40% biomass (c) 60% biomass (Example 3).
DETAILED DESCRIPTION
[0011] With respect to the use of substantially any plural and/or singular terms herein, those having skill in the art can translate from the plural to the singular and/or from the singular to the plural as is appropriate to the context and/or application. The various singular/plural permutations may be expressly set forth herein for sake of clarity. 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. Throughout this specification, the word “comprise”, or variations such as “comprises” or “comprising” or “containing” or “has” or “having”, or “including but not limited to” wherever used, 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.
[0012] Reference throughout this specification to “some embodiments”, “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment may be included in at least one embodiment of the present disclosure. Thus, the appearances of the phrases “in some embodiments”, “in one embodiment” or “in an embodiment” in various places throughout this specification may not necessarily all refer to the same embodiment. It is appreciated that certain features of the disclosure, which are, for clarity, described in the context of separate embodiments, may also be provided in combination in a single embodiment. Conversely, various features of the disclosure, which are, for brevity, described in the context of a single embodiment, may also be provided separately or in any suitable sub-combination.
[0013] The term “about” as used herein encompasses variations of +/-5% and more preferably +/-2.5%, as such variations are appropriate for practicing the present invention.
[0014] The term “biomass” as used herein refers to renewable organic material that comes from plants and animals. Exemplary biomass materials employed in the present invention include, but are not limited to, sugarcane bagasse, rice husk, ground nut husk, straw fibers, coconut shell powder and other natural fibers.
[0015] The present disclosure provides a process to convert polyolefin and polyolefin/biomass in a single step into low sulphur hydrocarbon fuel.
[0016] In some embodiments, the process for producing hydrocarbon fuel, comprises: a) subjecting a feed comprising a polyolefin to pyrolysis at a

temperature of 350°C-550°C in presence of a catalyst comprising Ni/Mo/Mg (OR)2; and b) subjecting vapors generated during pyrolysis to condensation to produce the hydrocarbon fuel.
[0017] Figure 1 shows an exemplary set-up of a pyrolysis reactor that may be used to carry out the process of the invention.
[0018] In some embodiments, the feed comprises a polyolefin and biomass. Accordingly, in some embodiments, the process for producing hydrocarbon fuel, comprises: a) subjecting a feed comprising a polyolefin and biomass to pyrolysis at a temperature of 350°C-550°C in presence of a catalyst comprising Ni/Mo/Mg (OR)2; and b) subjecting vapors generated during pyrolysis to condensation to produce the hydrocarbon fuel.
[0019] The step of subjecting the feed comprising a polyolefin or polyolefin/biomass to pyrolysis at a temperature of 350°C-550°C in presence of a catalyst comprising Ni/Mo/Mg (OR)2 converts the feed directly in a single step into vapors of hydrocarbon fuel which are condensed to provide the hydrocarbon fuel in liquid form.
[0020] In embodiments where the feed comprises a mixture of a polyolefin and biomass, the polyolefin constitutes about 40-80% by weight of the feed and biomass constitutes about 20-60% of the feed. In some embodiments, the feed comprises about 50-80% by weight of polyolefin and about 20-50% by weight of biomass or about 60-80% by weight of polyolefin and about 20-40% by weight of biomass or about 40-70% by weight of polyolefin and about 30-60% by weight of biomass or about 50-70% by weight of polyolefin and about 30-50% by weight of biomass or about 40-60% by weight of polyolefin and about 40-60% by weight of biomass or about 50% by weight of polyolefin and about 50% by weight of biomass.

[0021] In some embodiments, the feed comprises about 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80% by weight of a polyolefin and about 60%, 55%, 50%, 45%, 40%, 35%, 30%, 25%, or 20% by weight of biomass respectively.
[0022] In some embodiments, the polyolefin employed in the present process is selected from polyethylene, polypropylene, a copolymer of polypropylene and polyethylene, a terpolymer of polypropylene and polyethylene, or a combination thereof. In some embodiments, the polyethylene is selected from high density polyethylene (HDPE), low density polyethylene (LDPE), linear low-density polyethylene (LLDPE), or any combinations thereof. In some embodiments, the polyolefin employed in the present process is polypropylene.
[0023] In some embodiments, the feed comprises polypropylene and sugarcane bagasse; polyethylene and sugarcane bagasse; polypropylene and rice husk; polyethylene and rice husk and the like.
[0024] In some embodiments, the catalyst is added in an amount of about 2-5 % by weight of the feed, including values and ranges thereof, such as about 2-4.5 wt%, 2-4 wt%, 2-3.5 wt%, 2-3 wt%, 3-5 wt%, 3-4.5 wt%, 3-4 wt%, 4-5 wt%, 2 wt%, 2.2 wt%, 2.4 wt%, 2.5 wt%, 2.7 wt%, 2.9 wt%, 3 wt%, 3.2 wt%, 3.4 wt%, 3.5 wt%, 3.7 wt%, 3.9 wt%, 4 wt%, 4.2 wt%, 4.4 wt%, 4.5 wt%, 4.7wt%, 4.9 wt%, or 5 wt%.
[0025] In some embodiments, the temperature for pyrolysis of the feed ranges from 350°C-550°C, including values and ranges thereof, such as about 350°C-550°C, 350°C-525°C, 350°C-500°C, 350°C-480°C, 350°C-450°C, 350°C-425°C, 350°C-400°C, 380°C-550°C, 380°C-525°C, 380°C-500°C, 380°C-475°C, 380°C-450°C, 380°C-425°C, 400°C-550°C, 400°C-525°C, 400°C-500°C, 400°C-450°C, 450°C-550°C, 450°C-525°C, 450°C-500°C, 500°C-550°C, 350°C, 375°C, 400°C, 425°C, 450°C, 475°C, 500°C, 525°C, or 550°C.
[0026] In some embodiments, the yield of the hydrocarbon fuel provided by the process of producing hydrocarbon fuel of the present disclosure is about 40-70%,

including values and ranges thereof, such as about 40-60%, 40-50%, 44-55%, 50-70%, 50-60%, or 59-62%.
[0027] The present disclosure also provides a hydrocarbon fuel, wherein the hydrocarbon fuel comprises C6-C24 carbon and has an aliphatic content of about 75–93 wt%.
[0028] The hydrocarbon fuel provided by the present method comprises C6-C24 carbon. For example, in some embodiments, the hydrocarbon fuel comprises C6-C24, C6-C22, C6-C20, C6-C18, C6-C16, C8-C24, C8-C22, C8-C20, C8-C18, C8-C16, C10-C24, C10-C22, C10-C20, C10-C18, C12-C24, or C18-C24, carbon. In some embodiments, the hydrocarbon fuel comprises C6-C18 carbon.
[0029] In some embodiments, the hydrocarbon fuel provided by the present method has an aliphatic content of about 75-93 wt%, including values and ranges thereof, such as about 75-90%, 75-85%, 75-80%, 80-93%, 80-90%, 80-85%, 83-88%, 85-93%, or 85-90% and an aromatic content of less than 12%, such as less than 10%, less than 8%, less than 7%, less than 5%, about 0.1-12%, about 0.1-10%, about 0.1-7%, about 1-12%, or about 1-7%.
[0030] In some embodiments, the hydrocarbon fuel of the present disclosure has a sulphur content of about 0.15% or less, such as about 0.01-0.15%, 0.1-0.15%, or 0.05-0.15%.
[0031] The present disclosure also provides a catalyst having a formula: Ni/Mo/Mg (OR)2, wherein the R group is selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, or pentyl. In an exemplary embodiment, the catalyst has a formula: Ni/Mo/Mg (OC2H5)2.
[0032] In some embodiments, Ni, Mo, and Mg are present in the catalyst at a molar ratio range of 5:0.1:1 to 5:0.2:1, including values and ranges thereof. In some embodiments, Ni, Mo, and Mg are present in the catalyst at a molar ratio of 5:0.2:1.

[0033] The present disclosure also provides a method for preparing the catalyst. In some embodiments, the method comprises a) adding precursor compounds, Ni(NO3)2, (NH4)6Mo7O24 and Mg(OC2H5)2, to water to obtain a mixture; b) adding an acid to the mixture to obtain an acidified mixture; c) heating the acidified mixture at about 80-100°C for about 1.5-3 hours followed by evaporation to obtain a viscous mass; and d) drying the viscous mass followed by combustion to obtain the catalyst.
[0034] In some embodiments, the acid added to the mixture of the precursor compounds is selected from citric acid, tartaric acid, ascorbic acid, or any combination thereof.
[0035] In some embodiments, the acidified mixture is heated to a temperature of about 80-100°C, including values and ranges thereof, such as about 80-90°C, 85-90°C, 90-100°C, 80°C, 85°C, 90°C, 95°C, or 100°C, for about 1.5-3 hours, such as about 1.5-2 hours, 2 hours, or 2-3 hours. The step of heating the acidified mixture results is a green colored mixture which is then evaporated to form a viscous mass. The viscous mass is then dried at about 100-120°C, such as at about 110°C, for 5-7 hours. The dried mass is then combusted to provide the catalyst. In some embodiments, the dried mass is combusted at a temperature of about 650-750°C for about 1.5-3 hours.
[0036] It is to be understood that the foregoing descriptive matter is illustrative of the disclosure and not a limitation. While considerable emphasis has been placed herein on the particular features of this disclosure, it will be appreciated that various modifications can be made, and that many changes can be made in the preferred embodiments without departing from the principles of the disclosure. Those skilled in the art will recognize that the embodiments herein can be practiced with modification within the spirit and scope of the embodiments as described herein. Similarly, additional embodiments and features of the present disclosure

will be apparent to one of ordinary skill in art based upon description provided herein.
[0037] Descriptions of well-known/conventional methods/steps and techniques are omitted so as to not unnecessarily obscure the embodiments herein. Further, the disclosure herein provides for examples illustrating the above-described embodiments, and in order to illustrate the embodiments of the present disclosure certain aspects have been employed. The examples used herein for such illustration are intended merely to facilitate an understanding of ways in which the embodiments herein may be practiced and to further enable those of skill in the art to practice the embodiments herein. Accordingly, the following examples should not be construed as limiting the scope of the embodiments herein.
EXAMPLES
Example 1: Synthesis of the catalyst
[0038] Ni/Mo/Mg(OC2H5)2 catalyst with molar ratio 5:0.2:1 was synthesized by Sol-Gel method. Desired amounts of Ni(NO3)2.6H2O, (NH4)6Mo7O24.4H2O and Mg(OC2H5)2 of 99.9 % purity were dissolved in 20 ml of deionised water, further 2 gm of citric was added and the mixture was heated at 90°C for 2 hour. The resulting green colored mixture was then evaporated on hot plate to form a viscous mass. The viscous mass (wet cake) was then dried in a vacuum oven at 110°C for 6 hours. The dried mass was then ground to fine powder and combusted in a muffle furnace at 700 °C for 2 hours.
Example 2: Process of producing hydrocarbon fuel from polypropylene
[0039] Feedstock employed in the process was polypropylene and sugarcane bagasse biomass. The catalyst synthesized in Example 1 was employed for the conversion. The experimental set up included controlled nitrogen gas input, heating assembly, three neck quartz reactor attached with thermocouple, condenser

and collection flask. The experiment was carried out in one step, in which 16 g polypropylene resin and 2.4 wt% catalyst Ni/Mo/Mg(OR)2 was mixed together and fed into the three neck quartz reactor for pyrolysis. Before starting the reaction, nitrogen gas was purged for 10 min into the reactor to create moderate inert atmosphere. The experiment was carried out in the temperature range of 350-550°C. The organic vapors coming from burning of polypropylene during pyrolysis were passed through the condenser which condensed the vapors into a hydrocarbon liquid which was collected in a flask and a black solid residue was collected from the reactor. Uncondensed gases produced during the experiment were passed through oil bath and vent off. The time required for completion of the pyrolysis process was 1 hour.
[0040] Table 1 shows the elemental analysis of the obtained hydrocarbon fuel. Table 1: Elemental analysis of hydrocarbon oil obtained fioin catalytic pyrolysis of PP

Sample N% C% H% S%
Hydrocarbon oil 0 09 85.72 14.20 0.15
[0041] GC-MS chromatogram showed that pyrolysis of polypropylene leads to a fraction mainly in the region of C6–C18, which is in the diesel and gasoline region (Figure 2).
[0042] 13C-NMR spectrum (Figure 3) shows that the hydrocarbon fuel obtained from polypropylene comprises around 69% saturated aliphatic compounds, 24% aromatics and 6.7% alkenes. The NMR analysis showed that the hydrocarbon fuel mainly contains aliphatic carbon atoms bonded to other aliphatic carbon atoms.
[0043] The overall average yield was calculated and was found to be 59-62% of the liquid product (Table 2).
Example 3: Process of producing hydrocarbon fuel from polypropylene (PP) and biomass

[0044] The amount of polypropylene used in this Example was 40-80% with different concentration of sugarcane bagasse biomass (60-20%). Polypropylene, sugarcane bagasse biomass and catalyst were mixed together and fed into the reactor for pyrolysis. Before starting the reaction, nitrogen gas was purged for 10 min into the reactor to create moderate inert atmosphere. The experiment was carried out in the temperature range of 350-550 °C. The obtained product was hydrocarbon oil and carbon residue. The time required for the completion of the pyrolysis process was 1 hour. The yield was calculated and found in the range of 44-55% as mentioned in Table 2.
Table 2: Yield of Hydrocarbon oil

5. No. Polypropylene (wt%) Sugarcane bagasse SB (wt%) Hydrocarbon Yield (%)
1 100 0 59-62
2 SO 20 51-55
3 60 40 47-50
4 40 60 44-50
[0045] Figure 4 shows the GC-MS chromatogram of hydrocarbon oil from the catalytic pyrolysis of PP and sugarcane bagasse biomass (a) 20 % biomass (b) 40% biomass (c) 60% biomass.
[0046] Figure 5 shows the 13C NMR spectra of hydrocarbon fuel oil obtained from polypropylene (PP) and sugarcane bagasse biomass (a) 20 % biomass (b) 40% biomass (c) 60% biomass.
[0047] Table 3 shows the amount of saturated aliphatic, aromatic, and alkene compounds present in the hydrocarbon fuel of Example 3 based on the 13C NMR spectra.

Table 3: Composition of hydrocaibon oil from NMR study

Hydrocarbon oil composition by 13C NMR
20% biomass 40% biomass 60% biomass
Aliphatic 88% 87% 83%
Aromatic 7% 7% 12%
Alkenes 5% 6% 5%
Example 4: Comparison with other catalysts
[0048] A co-pyrolysis of polypropylene and biomass was carried out in the presence of several known catalysts and the catalysts of the present disclosure. Table 4 shows the % yield of the hydrocarbon fuel and the aliphatic content of the hydrocarbon fuel provided by these catalysts.
Table 4: Comparison with other catalysts

Ni/Mo/Mg
(OR)2 NiMo Al2O3-NiMo NiMo/MgO Zeolite Molecular sieves
Hydrocarbon fuel yield % 50-62% Ni-Mo/
Laponite
catalysts
- 37–68% 15-75% 70% HZSM-5
molecular
sieve
catalyst:
Yield: 42-50%
Aliphatic content % 76-93% 70-75% 2.9-14.5% 14–16% 15-25% 34%

We claim:
1. A process for producing hydrocarbon fuel, comprising:
a) subjecting a feed comprising a polyolefin to pyrolysis at a temperature of 350°C-550°C in presence of a catalyst comprising Ni/Mo/Mg (OR)2; and
b) subjecting vapors generated during pyrolysis to condensation to produce hydrocarbon fuel.

2. The process as claimed in claim 1, wherein the feed comprises the polyolefin and biomass.
3. The process as claimed in claim 2, wherein the polyolefin constitutes about 40-80% by weight of the feed and biomass constitutes about 20-60% of the feed.
4. The process as claimed in any one of claims 1 to 3, wherein the polyolefin is selected from polyethylene, polypropylene, a copolymer of polypropylene and polyethylene, a terpolymer of polypropylene and polyethylene, or a combination thereof.
5. The process as claimed in claim 4, wherein the polyethylene is selected from high density polyethylene (HDPE), low density polyethylene (LDPE), linear low density polyethylene (LLDPE), or any combinations thereof.
6. The process as claimed in any one of claims 2 to 5, wherein biomass is selected from sugarcane bagasse, rice husk, ground nut husk, straw fibers, coconut shell powder and other natural fibers.
7. The process as claimed in any one of claims 2 to 6, wherein the feed comprises polypropylene and sugarcane bagasse.
8. The process as claimed in any one of claims 1 to 7, wherein the R group in the catalyst is selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, or pentyl.

9. The process as claimed in any one of claims 1 to 8, wherein Ni, Mo, and Mg in
the catalyst are at a molar ratio of 5:0.2:1.
10. The process as claimed in any one of claims 1 to 9, wherein the catalyst is added in an amount of about 2-5 wt% of the feed.
11. The process as claimed in any one of claims 1 to 10, wherein yield of the hydrocarbon fuel is about 40-70%.
12. The process as claimed in any one of claims 1 to 11, wherein the hydrocarbon fuel comprises C6-C24 carbon.
13. The process as claimed in any one of claims 1 to 12, wherein the hydrocarbon fuel has an aliphatic content of about 75–93 wt%.

14. A catalyst having a formula: Ni/Mo/Mg (OR)2, wherein the R group is selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, or pentyl.
15. The catalyst as claimed in claim 14, wherein Ni, Mo, and Mg in the catalyst are at a molar ratio of 5:0.1:1 to 5:0.2:1.
16. A method for preparing the catalyst as claimed in claim 14 or 15, comprising:

(a) adding Ni(NO3)2, (NH4)6Mo7O24 and Mg(OC2H5)2 to water to obtain a mixture;
(b) adding an acid to the mixture to obtain an acidified mixture;
(c) heating the acidified mixture at about 80-100°C for about 1.5-3 hours followed by evaporation to obtain viscous mass;
(d) drying the viscous mass followed by combustion to obtain the catalyst.

17. A hydrocarbon fuel, wherein the hydrocarbon fuel comprises C6-C24 carbon and has an aliphatic content of about 75–93 wt%.