AND GREEN CARBON/CNT

FIELD OF THE INVENTION

[0001] The present invention generally relates to process of preparation of carbon negative hydrogen. Particularly, the present invention relates to an improved process for simultaneous preparation of carbon negative H2, hydrogen enriched natural gas or syn gas along with graphitic carbon/ carbon nanotubes (CNT) production using biogas as feed material.

BACKGROUND OF THE INVENTION

[0002] Background description includes information that may be useful in understanding the present invention. It is not an admission that any of the information provided herein is prior art or relevant to the presently claimed invention, or that any publication specifically or implicitly referenced is prior art.

[0003] Globally, environment pollution and climate change are a major concern. Various factors contribute to the environment pollution and claimate change. H2 economy is boosting up world wide. Hydrogen is considered to be the clean energy source to reduce carbon foot print in hard to abate sectors like steel, fertilizers etc. Green hydrogen or carbon negative hydrogen are considered to be one of the most clean and ecological energy for the future and it is considered to be one area of competitiveness for the various oil companies.

[0004] Nowadays numerous synthesis gas manufacturing processes are available in the prior art. Syngas can be produced by steam reforming of methane, dry reforming of methane, partial oxidation of methane or decomposition of methanol (mainly used in the hydrogen production for the fuel cell because methanol is high in energy density and is also easy to transport). Synthesis gas is produced with extremely high selectivity using dry reforming process.

[0005] Currently, green hydrogen gas is produced through electrolysis using renewable electricity or from renewable biomass, either through thermochemical processes or by using microorganisms and biotechnological methods.

[0006] Steam reforming of natural gas/ methane produces 10-13 Kg CO2/ Kg of H2 produced leading to more green house gas footprint. Electrolysis process is enevironmental friendly, however it requires 50-75 KWh energy to produceper Kg of H2. [0007] Thus, there is an unmet need for the improved process of manufacturing carbon negative hydrogen along with the carbon nanotubes (CNT) which utilizes less energy and results in no CO2 emission.

OBJECTS OF THE INVENTION

[0008] An object of the present invention is to provide a method of production of carbon negative hydrogen along with carbon nanotubes.

[0009] Another object of the present invention is to provide a method of production of syn gas production with high H2 concentration.

[0010] Another object of the present invention is to provide a method of production of hydrogen enriched natural gas.

[0011] Another object of the present invention is to provide a method of production of carbon negative hydrogen along with carbon nanotubes having CNT of longer length and smaller diameter.

[0012] Another object of the present invention is to provide a method of production of crabon negative hydrogen and CNT/ graphitic carbon along with carbon nanotubes which utilizes low energy and results in no CO2 emission.

SUMMARY OF THE INVENTION

[0013] The present invention relates to an improved process for simultaneous preparation of carbon negative H2, hydrogen enriched natural gas or syn gas along with graphitic carbon/ CNT production using biogas as feed material.

[0014] In one aspect, the present invention relates to a method of producing carbon negative hydrogen along with carbon nanotubes (CNT) comprising the steps of:

(a) digesting food waste and lignocellulosic biomass in anaerobic digester to obtain a raw biogas;

(b) optionally subjecting the raw biogas into pressure swing adsorption to obtain a feed gas;

(c) reacting the feed gas or the raw biogas in a fluidized bed reactor in presence of a Ni/ waste E-cat catalyst or Ni/ steamed biochar catalyst to obtain product gas and spent catalyst consisting of graphitic carbon nanotubes; and

(d) separating the spent catalyst consisting of graphitic carbon nanotubes using CNT separation process to obtain a purified carbon nanotubes. [0015] In an embodiment of the present invention, the feed gas comprises less than 5% CO ₂ .

[0016] In another embdoiment of the present invention, the feed gas comprises methane and CO ₂ in a ratio of 50:50 v/v to 90: 10 v/v respectively.

[0017] In another embodiment of the present invention, the fluidized bed reactor is one or multiple fluidized bed reactors arranged in series or in parallel operation.

[0018] In another embodiment of the present invention, the reaction in fluidized bed reactor is carried out at a temperature in the range of 500°C to 750 °C and the operating pressure of the process is atmospheric.

[0019] In another embodiment of the present invention, the catalyst loading and feed flow according to GHSV is in the range of 500-2500 ml/g/h gas hourly space velocity (GHSV).

[0020] In another embodiment of the present invention, the CNT is multi-walled carbon nanotubes (MWCNT).

[0021] In another embodiment of the present invention, the method of producing carbon negative hydrogen along with carbon nanotubes (CNT) comprises the step of enriching green syn gas by subjecting the green syn gas into pressure swing adsorption to obtain hydrogen enriched green syn gas.

[0022] In another embodiment of the present invention, the method of producing carbon negative hydrogen along with carbon nanotubes (CNT) comprises the step of heating feed gas using plasma heater, solar heater, electricity or slip stream of product H2 before sending to fluidized bed reactor.

[0023] In another embodiment of the present invention, the method of producing carbon negative hydrogen along with carbon nanotubes (CNT) comprises the step of converting the syn gas into chemicals using chemical conversion unit.

[0024] In another embodiment of the present invention, the chemicals are selected from methanol, higher alcohols, dimethyl ether, olefins and gasoline range fuel.

[0025] In another embodiment of the present invention, the method of producing carbon negative hydrogen along with carbon nanotubes (CNT) comprises the step of heat integrating of cold feed gas with hot product gas coming from fluidized bed reactors.

[0026] In another embodiment of the present invention, the method further comprises recovering metal salts from the CNT separation unit and recycling back to prepare Ni/ E-cat catalyst. [0027] In another embodiment of the present invention, the method of producing carbon negative hydrogen along with carbon nanotubes (CNT) comprises the step of heat integrating of of feed gas slip stream with hot carbon product removed from fluidized bed reactor.

[0028] Various objects, features, aspects and advantages of the inventive subject matter will become more apparent from the following detailed description of preferred embodiments.

BRIEF DESCRIPTION OF THE FIGURES

[0029] Figure 1 represents process flow scheme- 1 for production of carbon negative hydrogen along with carbon nanotubes (CNT).

[0030] Figure 2 represents process flow scheme-2 for production of carbon negative syn gas along with carbon nanotubes (CNT).

[0031] Figure 3 represents process flow scheme-3 with heat integration for production of carbon negative hydrogen/ syn gas along with carbon nanotubes (CNT).

[0032] Figure 4 represents process flow scheme-4 with H2 as heating medium for production of carbon negative hydrogen along with carbon nanotubes (CNT).

[0033] Figure 5 shows the hydrogen yield of example 1 of the present invention.

[0034] Figure 6 shows scanning electron microscopy images showing presence of carbon nanotubes of example 1

[0035] Figure 7 represents Raman spectra of the product gas obtained in example 1 of the present invention.

[0036] Figure 8 shows the hydrogen yield of example 2 of the present invention..

[0037] Figure 9 shows scanning electron microscopy images showing presence of carbon nanotubes obtained in example 2 of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

[0038] The following is a detailed description of embodiments of the disclosure. The embodiments are in such detail as to clearly communicate the disclosure. However, the amount of detail offered is not intended to limit the anticipated variations of embodiments; on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the present disclosure as defined by the appended claims.

[0039] Unless the context requires otherwise, throughout the specification which follow, the word “comprise” and variations thereof, such as, “comprises” and “comprising” are to be construed in an open, inclusive sense that is as “including, but not limited to.” [0040] Reference throughout this specification to “one embodiment” or “an embodiment” means that a particular feature, structure or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the appearances of the phrases “in one embodiment” or “in an embodiment” in various places throughout this specification are not necessarily all referring to the same embodiment. Furthermore, the particular features, structures, or characteristics may be combined in any suitable manner in one or more embodiments.

[0041] As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” include plural referents unless the content clearly dictates otherwise. It should also be noted that the term “or” is generally employed in its sense including “and/or” unless the content clearly dictates otherwise.

[0042] In some embodiments, the numbers expressing quantities of ingredients, properties such as concentration, reaction conditions, and so forth, used to describe and claim certain embodiments of the invention are to be understood as being modified in some instances by the term “about.” Accordingly, in some embodiments, the numerical parameters set forth in the written description are approximations that can vary depending upon the desired properties sought to be obtained by a particular embodiment. In some embodiments, the numerical parameters should be construed in light of the number of reported significant digits and by applying ordinary rounding techniques. Notwithstanding that the numerical ranges and parameters setting forth the broad scope of some embodiments of the invention are approximations, the numerical values set forth in the specific examples are reported as precisely as practicable.

[0043] The recitation of ranges of values herein is merely intended to serve as a shorthand method of referring individually to each separate value falling within the range. Unless otherwise indicated herein, each individual value is incorporated into the specification as if it were individually recited herein.

[0044] All processes described herein can be performed in any suitable order unless otherwise indicated herein or otherwise clearly contradicted by context. The use of any and all examples, or exemplary language (e.g. “such as”) provided with respect to certain embodiments herein is intended merely to better illuminate the invention and does not pose a limitation on the scope of the invention otherwise claimed. No language in the specification should be construed as indicating any non-claimed element essential to the practice of the invention. [0045] The headings and abstract of the invention provided herein are for convenience only and do not interpret the scope or meaning of the embodiments.

[0046] The following discussion provides many example embodiments of the inventive subject matter. Although each embodiment represents a single combination of inventive elements, the inventive subject matter is considered to include all possible combinations of the disclosed elements. Thus if one embodiment comprises elements A, B, and C, and a second embodiment comprises elements B and D, then the inventive subject matter is also considered to include other remaining combinations of A, B, C, or D, even if not explicitly disclosed.

[0047] All publications herein are incorporated by reference to the same extent as if each individual publication or patent application were specifically and individually indicated to be incorporated by reference. Where a definition or use of a term in an incorporated reference is inconsistent or contrary to the definition of that term provided herein, the definition of that term provided herein applies and the definition of that term in the reference does not apply.

[0048] Groupings of alternative elements or embodiments of the invention disclosed herein are not to be construed as limitations. Each group member can be referred to and claimed individually or in any combination with other members of the group or other elements found herein. One or more members of a group can be included in, or deleted from, a group for reasons of convenience and/or patentability. When any such inclusion or deletion occurs, the specification is herein deemed to contain the group as modified thus fulfilling the written description that follows, and the embodiments described herein, is provided by way of illustration of an example, or examples, of particular embodiments of the principles and aspects of the present disclosure. These examples are provided for the purposes of explanation, and not of limitation, of those principles and of the disclosure.

[0049] It should also be appreciated that the present invention can be implementedin numerous ways, including as a system, a method or a device. In this specification, these implementations, or any other form that the invention may take, may be referred to as processes. In general, the order of the steps of the disclosed processes may be altered within the scope of the invention.

[0050] Various terms as used herein are shown below. To the extent a term used in a claim is not defined below, it should be given the broadest definition persons in the pertinent art have given that term as reflected in printed publications and issued patents at the time of filing. [0051] The term, “carbon negative hydrogen” as used herein refers to hydrogen gas produced using renewable feedstock like biogas and in the process of prdocution of hydrogen COj is fixed as solid carbon. Hence, there are zero emissions from this process.

[0052] The term “green syn gas” as used herein refers to mixture of hydrogen and carbon monoxide produced from reneable feedstock like biogas produced from food waste and lignocellulosic biomass

[0053] The catalysts used in the present invention are prepared by wet impregnation method using transition metals like Ni or Fe as active metals and with promoters like Cu and Zn. Waste equilibrium catalyst (E-cat catalyst) generated in fluid catalytic cracking unit (FCC) in oil refineries used as catalyst support material, which is otherwise landfilled. Transition metal concentration used in the examples are of 30 wt%. however, one can vary the % concentration of metal from 5% to 30% and process conditions like operating temperature and space velocity may be varied to achieve H2/ syn gas concentration.Preferablu the catalyst is Ni/waste E-cat catalyst or Ni/steamed biochar catalyst.E-catalyst used in the present invention comprises SiCW AI2O3 in the ratio of 1 to 4.

[0054] The fludized bed reactor used in the preset invention contains a single/ multiple reactors with feed gas distributor in the bottom. Feed gas passes through distributor and through a bed of fresh catalyst supported on gas distributor. Catalyst will be optionally reduced with feed gas CH4 or with H2 produced in the process to reduce the oxide form of the catalyst to metallic form. After the reduction process, reaction continues in the reactor with feed gas to several hours from 20 min- 60 h . Fluidized bed reactor may contain, internals like intermittent jets equipped with inert gas to dislodge the carbon formed in the reaction insitu . Fluidized bed will contain disengagement zone to restrict entrainment of catalyst from fluidized bed. At the downstream of fluidized bed to recover entrained catalyst cyclones are used. Fluidized bed can operate from bubbling regime to turbulent regime based on the density of fresh/ spent catalyst and the space velocity used. The fluidized bed reactor can be one or multiple fluidized bed reactors and the multiple fluidized bed reactors can be operated in series connection or in parallel connections.

[0055] The lignocellulose biomass as used in the present invention is the most abundant biomass resource on the earth that comprises wood (such as eucalyptus, beech, poplar and the like) and agricultural and forestry waste (such as rice straw, rice husk, wheat straw, corn stalks, wheat straws, sorghum stalks and the like). The lignocellulose biomass mainly comprises three major components, namely cellulose, hemicellulose and lignin.The three major components of lignocellulose biomass have different structures, the cellulose and the hemicellulose are high molecular polymers formed by connecting sugar units through glycosidic bonds, and the lignin is a biomacromolecule with a three-dimensional structure formed by a large number of benzene ring structures.

[0056] The food waste as used in the present invention is the waste obtained from any food, inedible parts of food, or removed from the food supply chain to be recovered or disposed. The food wastes include composted waste, crops ploughed in/not harvested waste, anaerobic digestion waste, bio-energy production waste, co-generation waste, incineration waste, disposal to sewer waste, landfill waste or discarded to sea waste.

[0057] In a general embodiment, the present invention relates to an improved process for simultaneous preparation of carbon negative H2, hydrogen enriched natural gas or syn gas along with graphitic carbon/ CNT production using biogas as feed material.

[0058] The present disclosure uses methane/ biogas (combination of methane and CO2) from anaerobic digestion of biomass as feed gas for production of carbon negative H2/ syn gas/ H-CNG. Green biogas is decomposed in presence of a catalyst. In this process methane is decomposed to hydrogen and solid carbon in the form of graphitic carbon/ carbon nano tubes. There are no CO2 emissions involved in the process of present invention. CO2 present in biogas is converted into CO. Based on different process configurations and process conditions used in the present invention, the carbon negative hydrogen/ carbon negative H- CNG and carbon negative syn gas are obtained along with green CNT production. Thermodynamically, the method of present invention requires only 5-6 KWH for per Kg H2 production which is almost 10 times lower than the conventional electrolysis process energy requirement.

[0059] The present innovation produces simultaneously carbon negative H2/ hydrogen enriched natural gas / syn gas along with graphitic carbon/ CNT starting from raw biogas as feed material. Raw biogas is produced from anaerobic digestion of lignocellulosic biomass/ municipal solid waste or food waste or combination of all. Raw biogas consists of majorly methane upto 50 vol% and CO2 upto 50 Vol% and trace amounts of H2S and N2.

[0060] Raw biogas is optionally be fed to pressure swing adsorption to remove the CO2 from raw biogas and prepare a feed gas with varying amount of CO2 ranging from 5 vol% to 50 vol% and rest is methane. This biogas is fed to fluidized bed reactor where it has catalyst based on transition metal (Example: 30% Ni/ E- cat or 30% Ni/ Steamed biochar). In the presence of catalyst methane and CO2 present in the feed gas is catalytically decomposed according to the below possible reactions:

CH ₄ - C +2H ₂ co ₂ + H ₂ ^ CO+ H ₂ O

CO2- C+O2

2CO ₂ - 2CO+O ₂

[0061] In first embodiment, the present invention relates to a method of producing carbon negative hydrogen along with carbon nanotubes (CNT) comprising the steps of:

(a) digesting food waste and lignocellulosic biomass in anaerobic digester to obtain a raw biogas;

(b) optionally subjecting the raw biogas into pressure swing adsorption to obtain a feed gas;

(c) reacting the feed gas or the raw biogasin a fluidized bed reactor in presence of a Ni/ waste E-cat catalyst or Ni/ steamed biochar catalyst to obtain green syn gas, compressed natural gas and spent catalytic consisting of graphitic carbon nanotubes; and

(d) separating the spent catalytic consisting ofgraphitic carbon nanotubesusing CNT separation processto obtain a purified carbon nanotubes.

[0062] In another embodiment, the present invention relates to a method of producing carbon negative hydrogen along with carbon nanotubes (CNT) comprising the steps of:

(a) digesting food waste and lignocellulosic biomass in anaerobic digester to obtain a raw biogas;

(b) reacting the raw biogas as feed gas in a fluidized bed reactor in presence of a Ni/ waste E-cat catalyst or Ni/ steamed biochar catalyst to obtain green syn gas, compressed natural gas and spent catalytic with graphitic carbon nanotube; and

(c) separating the spent catalytic consisting of graphitic carbon nanotubesusing CNT separation process to obtain a purified carbon nanotubes.

[0063] In another embodiment, the present invention relates to a method of producing carbon negative hydrogen along with carbon nanotubes (CNT) comprising the steps of:

(a) digesting food waste and lignocellulosic biomass in anaerobic digester to obtain a raw biogas;

(b) subjecting the raw biogas into pressure swing adsorption to obtain a feed gas;

(c) reacting the feed gas in a fluidized bed reactor in presence of a Ni/ waste E-cat catalyst or Ni/ steamed biochar catalyst to obtain green syn gas, compressed natural gas and spent catalytic consisting ofgraphitic carbon nanotubes; and

(d) separating the spent catalytic consisting ofgraphitic carbon nanotubesusing CNT separation process to obtain a purified carbon nanotubes. [0064] In another embodiment of the present invention, the reaction in fluidized bed reactor is carried out at a temperature in the range of 500 °C to 750 °C. Preferably, at a temperature range of 650°C to 750°C.

[0065] In another embodiment of the present invention, the reaction in fluidized bed reactor is carried out at a temperatureof about 500°C, about 550°C, about 575°C, about 600°C, about 610°C, about 620°C, about 630°C, about 640°C, about 650°C, about 660°C, about 670°C, about 680°C, about 690°C, about 700°C, about 710°C, about 720°C, about 730°C, about 740°C, and about 750°C.

[0066] In another embdoiment of the present invention, the feed gas comprises methane and CO2 in a ratio of 50:50 v/v to 90: 10 v/v respectively. Preferably, in a ratio of 70:30 v/v.

[0067] In another embodiment of the present invention, the catalyst loading and feed flow according to GHSV is in the range of 500-2500 ml/g/h gas hourly space velocity (GHSV). Preferably, the catalyst loading and feed flow according to GHSV isin the range of 500-1000 ml/g/h, 1000-1500 ml/g/h, 1000-2000 ml/g/h and 1000-2500 ml/g/h. More preferably, the catalyst loading and feed flow according to GHSV isin the range of 1000-1500 ml/g/h.

[0068] In another embodiment of the present invention, the active metal concentration of the catalyst on the support is in the range of from 5% to 30% and the catalyst can run from 1 h to 50h time on stream to produce various grades of CNT. Further increase in metal loading is possible.

[0069] In another embodiment of the present invention, the figure 1 shows the flow scheme- 1 for method of producing carbon negative hydrogen along with carbon nanotubes (CNT). According to the present invention, the biomass/ food waste/ MSW (a) is introduced into anaerobic digester (1) to obtain raw feed gas (b). The raw feed gas can opitionally be subjected to remove CO in pressure swing adsorption (PSA) (2) to obtain purified biogas from (c). The feed gas (d) is entered into fluidized bed reactor/ multiple reactors (3) for catalystic processing in presence of catalyst (e) to obtain H2,/H-CNG / Syn gas (f)and Spent catalyst consisting ofgraphitic C/ CNT (k). The H2,/ H-CNG / Syn gas (f) is collected in product gas collector (4) to obtain product H-CNG/ H2 (i). The product (i) is passed to compressor (5) to obtain compressed product gas. The spent catalyst consisting ofgraphitic C/ CNT (k) is passed to CNT separation unit (6) to obtain separated product carbon (1).

[0070] In an embodiment of the present invention, optionally the product gas (g) from product gas collector (4) can be fed in to PSA(2) to remove CO2 in the product gas. The enriched product gas (h) from PSA (2) can be fed into compressor (5) to obtain compressed product gas.

[0071] In another embodiment of the present invention, the figure 2 shows the flow scheme-2 for method of producing carbon negative syngas where feed gas contains CO2>5 vol%. According to the present invention, the biomass/ food waste/ MSW (a) is introduced into anaerobic digester (1) to obtain raw feed gas (b). The raw feed gas (b) is entered into fluidized bed reactor/ multiple reactors (3) for catalystic processing in presence of catalyst (e) to obtain H2,/H-CNG I Syn gas (f) and spent catalyst consisting ofgraphitic C/ CNT (k). The H2,/ H-CNG I Syn gas (f) is collected in product gas collector (4) to obtain product H-CNG/ H2 (i). The product (i) is passed to compressor (5) to obtain compressed product gas. The spent catalyst consisting ofgraphitic C/ CNT (k) is passed to CNT separation unit (6) to obtain separated product carbon. The recovered catalyst (r) from CNT separation unit (6) is recycled as catalyst precursors for catalyst manufacturing.

[0072] In another embodiment of the present invention, the figure 3 shows the flow Scheme-3with heat integration for method of producing carbon negative hydrogen along with carbon nanotubes (CNT) wherein the feed gas (d) is obtained after heating using the heating options (3a) such as plasma heater or solar heater.

[0073] In an embodiment of the present invention, figure 3 depicts the heat integration of streams wherein the stream Cl, which is cold feed gas can be heat exchanged with hot product gas coming from fluidized bed reactor(3). Stream Hl which is hot feed gas can be fed to fluidized bed reactor (3) for catalytic decomposition. In another embodiment, the feed gas slip stream C2 can be heat exchanged with hot carbon product removed from reactor. For feed heating purpose, one can use the hot carbon product (stream number H2) generated in the process as combustion medium in feed heater (3a).

[0074] In an embodiment of the present invention, the hot carbon product is the spent catalyst consisting ofgraphitic carbon/CNT.

[0075] In another embodiment of the present invention, the figure 4 shows the flow scheme-4 with heat integration using H2 as heating medium for the method of producing carbon negative hydrogen along with carbon nanotubes (CNT) wherein along with the above mentioned heat integration options, slip stream of H2 separated in PSA can be used for feed heating purpose since H2 energy medium does not produce any further emissions.

[0076] In another embodiment of the present invention, the product gas obtained can contain mixture of H2, CO and unconverted CO2 and CH4. This stream can be fed to the PSA to obtain the desired product as hydrogen or hydrogen enriched natural gas or syn gas (combination of Hi and CO).

[0077] In another embodiment of the present invention, the product gas of 100% Hi can be produced with the use of PSA by removing the unwanted gases and the product Hi can be compressed and delivered.

[0078] In another embodiment of the present invention, the feed gas consisting of COi<5 vol% can be used in fluidized bed reactor with the help of PSA to obtain Hi enriched product gas.

[0079] In another embodiment of the present invention, the syn gas can be produced without use of PSA.

[0080] In another embodiment of the present invention, the product gas from fludized bed reactor can be used for manufacturing chemicals.

[0081] Accordingly to the present invention, the graphitic carbon / MWCNT formed and deposited onto catalyst in the fluidized bed reactor. The spent catalyst consisting of the MWCNT / graphitic carbon is treated in CNT separation process to obtain purified CNT. The purified CNT can be utilized in batteries, polymer composites etc.

[0082] In another embodiment of the present invention, the recovered metal precursors of Ni and other transition metals in CNT separation process can be recycled for catalyst manufacturing.

[0083] In another embodiment of the present invention, the CNT separation process can be a combination of sonication, acid and alkali sequential treatment.

[0084] While the foregoing describes various embodiments of the disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof. The scope of the invention is determined by the claims that follow. The invention is not limited to the described embodiments, versions or examples, which are included to enable a person having ordinary skill in the art to make and use the invention when combined with information and knowledge available to the person having ordinary skill in the art.

EXAMPLES

[0085] The present invention is further explained in the form of following examples. However, it is to be understood that the following examples are merely illustrative and are not to be taken as limitations upon the scope of the invention.

[0086] Example 1

[0087] Catalyst preparation: Measured amount of Ni nitrate hexa hydrate, with optional promoters like Zn nitrate and Cu nitrate salts were dissolved in distilled water. Equilibrium catalyst from commercial fluid catalytic cracking unit is calcined at 550 degC for 5h in air. Calcined support is mixed in metal salt solution to make up the catalyst of composition 30% Ni 2.5%Cu 2.5% Zn. For better Ni dispersion on catalyst 0.5% citric acid is used in wet impregnation process. After 1 h , the solution was dried using rota evaporator. Further, the emulsion is calcined at 550 degC for 5h. Final catalyst formulation is grinded and sieved. For all experiments > 45 micron to 150 micron particle size is used for fluidized bed experiments.

[0088] The same process is used for preparing the catalyst supported on steamed biochar as support. However, calcination was done under N2 atmosphere instead of air environment.

[0089] Example 2: Production of Product gas with CNT

[0090] Biogas was produced in anaerobic digester using food waste and lignocellulosic biomass. The raw biogas was fed to pressure swing adsorption (PSA) for removal of CO2 and to obtain feed gas. The feed gas containing <5% CCFwas fed into a fluidized bed reactor consisting of 25 g of 30% Ni/waste E-cat as a catalyst at a temperature of 660°C andgas hourly space velocity (GHSV) of 1000 ml/g/h for a period 10 hours. Periodically, the product gas was analysed using gas chromatography. It was observed consistently >75 vol% H2 in product gas (Figure 5). The analysis of spent catalyst shows presence of carbon nano tubes (Figure 6) and raman analysis shows ID/ IG of 1.14 (Fig 7).

[0091] Example 3: Production of Product gas with CNT

[0092] Biogas was produced in anaerobic digester using food waste and lignocellulosic biomass. The raw biogas was fed to pressure swing adsorption (PSA) for removal of CO2 and to obtain feed gas. The feed gas containing 70: 30 (vol: vol) Methane and CO2 was fed into a fluidized bed reactor consisting of 25 g of 30% Ni/FCC E-cat as a catalyst at a temperature of 660°C and gas hourly space velocity (GHSV) of 1000 ml/g/h for a period 2 hours. Periodically, the product gas was analysed using gas chromatography. It was observed that H2 rich syngas of H2/CO ratio of >2 was produced continually (Figure 8). Spent catalyst was analysed using scanning electron microscopy and observed the formation CNT of < 30-40 nm diameter and length upto 5 micron size (Figure 9).

[0093] It was observed that feed gas comprising CH4 and CO2 has generated CNT of longer length and smaller diameter i.e., with better aspect ratio compared to the feed gas comprising only CH4. [0094] A skilled artisan will appreciate that the quantity and type of each ingredient ingredients can be used in different combinations or singly. All such variations and combinations would be falling within the scope of present disclosure.

[0095] The foregoing examples are merely illustrative and are not to be taken as limitations upon the scope of the invention. Various changes and modifications to the disclosed embodiments will be apparent to those skilled in the art. Such changes and modifications may be made without departing from the scope of the invention.

ADVANTAGES OF THE PRESENT INVENTION

[0096] The present invention provides a method of producing carbon negative hydrogen along with carbon nanotubes (CNT) which gives high yield of H2 gas.

[0097] The present invention provides a method of producing carbon negative hydrogen along with carbon nanotubes (CNT) which utilizes low temperature.

[0098] The present invention provides a method of producing carbon negative hydrogen along with carbon nanotubes (CNT) which yields low temperature.

[0099] The presnt invention a method that produces various products like H2, H-CNG and chemical feedstock like syngas using same hardware.

[00100] The presnt invention provides a method of producing carbon negative hydrogen along with carbon nanotubes (CNT) that is zero emission process.

[00101] The present invention provides a method of producing carbon negative hydrogen along with carbon nanotubes (CNT) which utilizes low energy.