Process for hydrogen and solid carbon manufacture from waste

Abstract

The present invention concerns a process for manufacture of hydrogen from waste, the process comprising the steps (a) providing a feedstock F, said feedstock F comprising waste, (b) converting said feedstock F by a first pyrolysis reaction in a first pyrolysis reactor PR1 to a reaction product RP1, said reaction product RP1 comprising a gas stream GS, (c) separating said gas stream GS from said reaction product RP1 in a gas separation unit SU, (d) optionally providing a gaseous co-feedstock COF, and (e) converting said gas stream GS and the gaseous co-feedstock COF optionally provided in step d) by a second pyrolysis reaction in a second pyrolysis reactor PR2 into hydrogen H and granular pyrolytic carbon GPC and wherein the second pyrolysis reaction is conducted in a moving bed reactor, fluidized bed reactor or fixed bed reactor. The invention further concerns a chemical plant suited for said process.

Description

[0001] 240462WO01

[0002] 1

[0003] Process for hydrogen and solid carbon manufacture from waste

[0004] Technical area

[0005] The present invention relates to a process and a chemical plant for manufacture of hydrogen and solid carbon from 5 plastic waste.

[0006] Background of the invention

[0007] Pyrolysis of waste is an innovative method that enables the conversion of waste such as mixed plastic waste (MPW), end-of-life tires (ELT) and bio waste into valuable resources. Through this process, waste is subjected to high tem-10 peratures in the absence of oxygen, causing them to decompose into pyrolysis gas, pyrolysis oil and a solid residue.

[0008] In case of end-of-life tires (ELT), said solid residue comprises recovered Carbon Black. The main focus of the pyroly- sis of waste is on the pyrolysis oil, which serves as a feedstock for chemical processes such as steam cracking and partial oxidation. In most pyrolysis processes, the pyrolysis gas is not used as a feedstock for chemical processes, it is typically burned within the system to provide the necessary heat for the pyrolysis process.

[0009] 15

[0010] There is therefore a need for processes which are focused on the material use of pyrolysis gas, i.e., using said pyrol- ysis gas as a feedstock for chemical processes instead of burning the pyrolysis gas and thereby emit undesired CO2.

[0011] In methane pyrolysis a carbonaceous material and hydrogen are produced by decomposition of hydrocarbons which 20 could be used in several applications and thus integrated in a material recycle. Depending on the application, differ- ent properties and consequently, different morphologies of the carbonaceous material are preferred.

[0012] The term methane pyrolysis covers a wide range of different process technologies. The best known and most ad- vanced of these are: plasma pyrolysis, pyrolysis in a metal melting & metal salt melting reactor, moving bed & fluid-25 ized bed and fixed bed (catalytic) processes. They differ in the form of the energy used (thermal, electrical, etc.), the process conditions (temperature, pressure, etc.), the catalysts and / or auxiliary materials used and the process flow.

[0013] The solid carbon type generated in the methane pyrolysis depends on the reaction conditions, reactor and heating technology. Plasma processes yield carbon black, metal melting & metal salt melting processes yield carbon powder 30 and dense granular carbon is obtained from thermal decomposition in fixed, moving or fluidized bed reactors. Moving and fluidized bed reactors for methane pyrolysis are disclosed for example in US 2,982,622, US 2022 / 0152568, US 2021 / 0331918, WO 2023 / 57242.

[0014] For example, to produce carbon electrodes for the aluminum or steel industry dense granular pyrolytic carbon can be 35 used to substitute or blend standard petroleum coke. WO 2020 / 016186 discloses the use of pyrolytic carbon in blend compositions with petroleum coke for electrodes, especially anode for the aluminum production. 240462WO01

[0015] 2

[0016] CN 116426308 discloses a process comprising a thermal cracking of waste plastics to obtain hydrocarbon cracking oil gas, separating the hydrocarbon pyrolysis oil gas to obtain crude pyrolysis oil and pyrolysis gas and decarburizing the pyrolysis gas to obtain hydrogen and a nano carbon material. The plasma technology is disclosed for the decar- burizing step using high temperature of 1500 to 3500 °C to minimize by-products and soot generation.

[0017] 5

[0018] Such a nano carbon typically has the following properties: particle size of 20 to 200 nm, BET of 50 to more than 1000 m2 / g, bulk density of 0.1 to 0.5 g / cm3. The general disadvantages of the plasma technology are (i) need of high temperature and (ii) the fact that both hydrogen and carbon leave the reactor at a temperature of 500 to 1500 °C, thus, the plasma technology is not heat-integrated and always needs another process that takes its surplus heat. In 10 addition, the risk of undesired by-products rises with both higher concentration and varying of C2+ hydrocarbons.

[0019] Finally, nano carbon, also named Carbon Black, that is widely used as a reinforcing filler in tires and rubber products, as well as in plastics, coatings, printing inks cannot replace fossil based dense carbonaceous material like petroleum cokes that is used in the production of electrodes for the steel and aluminum industries. Properties of and impurities in “nano-carbon” formed by plasma pyrolysis are for example disclosed in Laurent Fulcheri, Vandad, Julien Rohani, 15 Elliott Wyse, Ned Hardman, Enoch Dames, International Journal of Hydrogen Energy, Vol.48, Issue 8, 2023, p.

[0020] 2920-2928 and references cited therein. The carbon content in such “nano-carbon” formed by plasma pyrolysis is usually below 70 wt.-%.

[0021] WO 2021 / 069394 A1 relates to a process and an installation for producing a hydrocarbon-containing and hydrogen-20 containing gas mixture from plastic waste. Said process comprises a first step (pyrolysis) and a second step (cata- lytic cracking). The pyrolysis results in gases (comprising long-chain hydrocarbons with more than four carbon at- oms), oils, tars, and solid residues. The solid residues are separated (preferably using a hotgas filter), and the re- maining components (gases, oils, and tars) are subjected to said catalytic cracking which results in short-chain hy- drocarbons (C1to C4) and hydrogen. Hence, all products formed in the pyrolysis (step 1) except the solid residues 25 are subjected to the catalytic cracking (step (2) at a temperature of 800 to 950 °C. Formation of coke / carbon is sup- pressed by adding 12 to 15 Vol.-% oxygen (e.g., in the form of air and / or steam) to the gas mixture during step 2. A catalyst selected from limestone, ZrO2, noble metal- and nickel catalysts is added in step 2. The resulting gas mixture is then purified. Accordingly, step 2 described herein refers to a catalytic cracking process in which a catalyst com- prising a metal (calcium, zirconium, noble metal(s), nickel) is employed and not to a thermolytic process in which es-30 sentially metal-free carbon particles are used as fluidized bed constituting solid particles. In contrast, the non-volatile portion of gaseous products formed by pyrolysis of plastic waste comprise impurities such as NH3, H2S, and HCl which may poison such catalysts employed in step 2 of WO 2021 / 069394 A1.

[0022] WO 2024 / 115488 A1 relates to a method for operating a cracking process produces a cracked gas from which one or 35 more product streams and one or more hydrocarbon-containing by-product-streams are recovered. The hydrogen product stream produced by said method is then subjected to combustion to provide thermal energy for a cracking process such as steam cracking. The feed streams utilized for said method are “clean” hydrocarbon streams which is 240462WO01

[0023] 3

[0024] indicated by exemplarily feed compositions disclosed in said document. Otherwise, the use of said product stream to generate heat by combustion would be less attractive, because impurities typically comprised in the non-condensa- ble portion of the products formed by plastic waste pyrolysis cause corrosion, fouling, and the like during combustion. Further, removal of such components prior to combustion would render the product of the method disclosed in WO 5 2024 / 115488 A1 too expensive. Impurities found in a hydrogen product stream produced from the non-volatile por- tion of plastic waste pyrolysis products comprise one or more of NH3, H2S, HCl and the like.

[0025] The article “Defossilization and decarbonization of hydrogen production using plastic waste (Andrei Veksha et al., Journal of Hazardous Materials 452 (2023) 131270; https: / / doi.org / 10.1016 / j.jhazmat.2023.131270) refers to hydro-10 gen and solid carbon production from plastics by pyrolysis (step (1) followed by a thermolysis process in a tube reac- tor (step 2). Three types of carbon are formed in step 2: a) carbon collected in a particle filter downstream of said tube reactor, b) carbon recovered from said tube reactor, and c) a carbon layer deposited on the inner wall of said tube reactor. Said tube reactor was only operated for short periods, e.g., one hour. The uncontrolled deposition of carbon in such an “empty tube” reactor likely results in plugging and fouling during longer operational times.

[0026] 15

[0027] US 2006 / 112639 A1 refers to a gasification process using a heterogeneous organic material comprised of municipal trash, refuse, garbage, or other post-consumer wastes, as feedstock in the presence of water. The gaseous products of said gasification process which are “rich in hydrogen, carbon monoxide, and other fuel gases of composition CxHy” are then purified in an acid gas scrubber whereby a product gas is formed. A further process for converting such gas-20 eous products into hydrogen and granular pyrolytic carbon GPC in the presence of a purposely added bed material is not taught by this document.

[0028] It is an objective of the present invention to provide a process for manufacture hydrogen from waste with an in- creased hydrogen yield.

[0029] 25

[0030] It is a further objective of the present invention to provide a process for manufacture hydrogen from waste with a de- creased CO2emission.

[0031] It is a further objective of the present invention to provide a process for waste pyrolysis in which the non-condensable 30 reaction products are utilized as a raw material for production of chemicals instead of incineration and combustion.

[0032] It is a further objective of the present invention to provide a hydrocarbon pyrolysis technology that ensures flexibility in view of fluctuating or changing hydrogen and hydrocarbon contents in the pyrolysis gas used as feedstock for the hydrocarbon pyrolysis.

[0033] 35

[0034] It is a further objective of the present invention to convert non-condensable hydrocarbon streams which comprise heteroatom-containing impurities and which are derived from plastic waste into hydrogen and dense pyrolytic carbon. 240462WO01

[0035] 4

[0036] It is a further objective of the present invention to provide dense pyrolytic carbon based on pyrolysis of waste that can replace fossil-based petroleum coke used in the production of electrodes or that can be used as blend material for said petroleum coke.

[0037] 5

[0038] It is a further objective of the present invention to provide a process for manufacture of solid carbon from waste wherein the solid carbon has a carbon content of at least 98 wt.-% (determined by ICP-AES),

[0039] It is a further objective of the present invention to provide a process for manufacture of solid carbon from waste 10 wherein the solid carbon has an average particle size of 0.5 mm (D10) to 10 mm (D90), preferably 2 mm (D10) to 8 mm (D90) (determined by sieving using sieves having defined mesh sizes).

[0040] It is a further objective of the present invention to provide a process for manufacture of hydrogen and solid carbon from waste having an improved heat integration.

[0041] 15

[0042] It is a further objective of the present invention to suppress fouling in a reactor in which a plastic waste derived pyrol- ysis gas is converted into hydrogen and carbon.

[0043] Summary of the invention

[0044] 20 These objectives are solved by a process for manufacture of hydrogen from waste, the process comprising the steps a) providing a feedstock F, said feedstock F comprising waste,

[0045] b) converting said feedstock F by a first pyrolysis reaction in a first pyrolysis reactor PR1 to a reaction product RP1, said reaction product RP1 comprising a gas stream GS,

[0046] c) separating said gas stream GS from said reaction product RP1 in a gas separation unit SU,

[0047] 25 d) optionally providing a gaseous co-feedstock COF,

[0048] e) converting said gas stream GS and the gaseous co-feedstock COF optionally provided in step d) by a second pyrolysis reaction in a second pyrolysis reactor PR2 into hydrogen H and granular pyrolytic carbon GPC, wherein the second pyrolysis reaction is conducted in a moving bed reactor, fluidized bed reactor or fixed bed reactor, wherein the temperature in the second pyrolysis reactor PR2 during step e) ranges from 1000 to 30 1600 °C, and wherein bed material is purposely added in step e).

[0049] These objectives are further solved by a chemical plant for manufacture of hydrogen from waste, the chemical plant comprising:

[0050] a) a first pyrolysis reactor PR1,

[0051] 35 b) a gas separation unit SU, said gas separation unit SU downstream of and fluidically connected to the first py- rolysis reactor PR1, 240462WO01

[0052] 5

[0053] c) a second pyrolysis reactor PR2, said second pyrolysis reactor PR2 downstream of and fluidically connected to the gas separation unit SU,

[0054] wherein said second pyrolysis reactor PR2 is selected from the group consisting of moving bed reactor, fluidized bed reactor and fixed bed reactor.

[0055] 5

[0056] The process described herein utilizes a gas stream called GS, which is a byproduct of the pyrolysis of waste mate- rial, specifically plastic waste. Instead of following the standard procedure of incinerating this gas stream, the present invention utilizes it as a raw material to produce hydrogen and granular pyrolytic carbon. Incineration of the gas stream typically results in the creation of undesired gases such as CO2, NOx, and SOx. By avoiding incineration, the 10 process eliminates the production of these undesired gases.

[0057] The main advantage of this process is that it yields a high amount of the desired products, namely hydrogen and highly pure granular pyrolytic carbon. These products can be further utilized in various applications. Additionally, in- stead of forming CO2, the carbon present in the gas stream is converted into solid, granular pyrolytic carbon. This 15 conversion process provides an alternative use for the carbon and avoids the release of CO2into the environment.

[0058] Both the hydrogen and granular pyrolytic carbon produced through this process have applications as reactants in the chemical industry and other industries. Their versatility allows for various uses, making them valuable resources in the broader context of sustainability and resource management.

[0059] 20

[0060] Figures

[0061] Figure 1 shows a first aspect of the process according to the present invention.

[0062] Figure 2 shows a second aspect of the process according to the present invention in which an internal recycle stream RF is utilized as co-feedstock.

[0063] 25 Figure 3 shows a third aspect of the process according to the present invention in which an external co-feedstock is utilized.

[0064] Figure 4 shows a fourth aspect of the process according to the present invention in which an internal recycle stream RF and an external co-feedstock are utilized.

[0065] 30 Detailed description of the invention

[0066] The present invention is further described below with reference to the embodiments, but the present invention is not limited to these embodiments, and any modifications of these embodiments, combinations of these embodiments or substitutions within the basic spirit of the present invention are still within the scope of the present invention as claimed.

[0067] 35

[0068] Definitions: 240462WO01

[0069] 6

[0070] In the context of the present description and the accompanying claims, the term “about” preferably means a deviation of the thus described value of ±10 %. In the context of the present invention, the term “combinations thereof” is inclusive of one or more of the recited elements. In the context of the present invention, the term “mixture thereof” is inclusive of one or more of the recited elements.

[0071] 5

[0072] The term “downstream of” is defined herein in respect to a succession of unit operations as located next to on the side which is in the flow direction of fluids passing said succession of unit operations.

[0073] The term “fluidically connected to” in respect to two or more units is defined herein that a fluid such as a particulate 10 solid, liquids, gases, and mixtures thereof can flow from one of such unit to the other such unit and flow through and / or along such an analytical unit. Two units “fluidically connected to” each other are for example connected by one or more pipes which each other or by screw conveyors or by extruders or by solids pumps.

[0074] A feedstock F is provided in step a). Said feedstock F comprises waste such as plastic waste (e.g., mixed plastic 15 waste (MPW), end-of-life tires (ELT)), bio waste and mixtures thereof. Preferably said feedstock F comprises plastic waste. In the context of the present invention, the term “plastic waste” refers to any plastic material discarded after use, i.e., the plastic material has reached the end of its useful life and is considered post-consumer waste. The plas- tic waste can be pure polymeric plastic waste, mixed plastic waste or film waste, including soiling, adhesive materi- als, fillers, residues etc. Content optionally comprised in plastic waste which is not subjected to a pyrolysis reaction 20 (e.g., inorganic fillers such as silica particles, carbon particles, glass fibers and the like) are defined as “inerts” herein.

[0075] The plastic waste may have an oxygen content, a nitrogen content, sulfur content, halogen content and optionally also a heavy metal content. The plastic waste can originate from any plastic material containing source. Accordingly, the term “plastic waste” includes industrial and domestic plastic waste and including used tires and agricultural and horticultural plastic material. The term “plastic waste” also includes used petroleum-based hydrocarbon material such 25 as used motor oil, machine oil, greases, waxes, etc.

[0076] Typically, plastic waste is a mixture of different plastic materials, including hydrocarbon plastics, e.g., polyolefins such as polyethylene (HDPE, LDPE) and polypropylene, polystyrene, copolymers comprising polystyrene, and poly- mers composed of carbon, hydrogen, and other elements such as chlorine, fluorine, oxygen, nitrogen, sulfur, sili-30 cone, etc., for example chlorinated plastics, such as polyvinylchloride (PVC), polyvinylidene chloride (PVDC), etc., nitrogen-containing plastics, such as polyamides (PA), polyurethanes (PU), acrylonitrile butadiene styrene (ABS), etc., oxygen-containing plastics such as polyesters, e.g., polyethylene terephthalate (PET), polycarbonate (PC), etc., and rubbers such as sulfur bridge crosslinked rubbers. More preferably, waste is mixed plastic waste (MPW) and comprises at least two members of the group comprising or preferably consisting of polyolefins polystyrene, copoly-35 mers comprising polystyrene, polyvinylchloride (PVC), polyvinylidene chloride (PVDC), polyamides (PA), polyure- thanes (PU), polyesters, polycarbonate (PC), and rubbers. 240462WO01

[0077] 7

[0078] Typically, the plastic material comprises additives, such as processing aids, plasticizers, flame retardants, pigments, light stabilizers, lubricants, impact modifiers, antistatic agents, antioxidants, etc. These additives may comprise ele- ments other than carbon and hydrogen. For example, bromine is mainly found in connection to flame retardants. Heavy metal compounds may be used as lightfast pigments and / or stabilizers in plastics. Cadmium, zinc, and lead 5 may be present in heat stabilizers and slip agents used in plastics manufacturing. The plastic waste can also contain residues. Residues in the sense of the invention are contaminants adhering to the plastic waste. The additives and residues are usually present in an amount of less than 50 wt.-%, preferably less than 30 wt.-%, more preferably less than 20 wt.-%, even more preferably less than 10 wt.-%, based on the total weight of the dry weight plastic.

[0079] Examples of rubber waste (which is also considered “plastic waste” in the sense of the present invention) include 10 end-of-life tires, rubber waste produced during manufacturing processes and discarded rubber containing products such as latex examining gloves and gaskets. End-of-life tires comprise further ingredients such as textiles and or- ganic and inorganic additives which may be separated from the rubber portion of end-of-life tires prior to pyrolysis. Pyrolysis oils obtained by pyrolysis of (predominantly) end-of-life tires are also known as tire pyrolysis oils (TPO). Bio waste comprises green waste, food waste, human waste, manure, sewage, sewage sludge, wood, agricultural 15 waste, and slaughterhouse waste.

[0080] Optionally, said feedstock F is pretreated before subjected to step b). Preferably, the feedstock F is pretreated before step b) by a method selected from the group comprising or preferably consisting of sorting, comminution, preheating, solvolysis, and combinations thereof. Such an optional pretreatment can for example increase the yield of reaction 20 product RP1 comprising a gas stream GS and / or result in a more economic first pyrolysis reaction in a first pyrolysis reactor PR1. For example, when applying sorting, the amount of more preferred plastic waste such as plastic waste having a high concentration of polyolefins and a low concentration of inerts can be archived which results in a higher yield of reaction product RP1 comprising a gas stream GS. Comminution may reduce the temperature required in step b) and thereby to a reduced amount of thermal energy required for step b). Preheating the feedstock F, prefera-25 bly to a temperature in the range of 200 to 360 °C can also reduce the thermal energy required in step b). Further- more, such a preheating can reduce the amount of undesired chlorine which may be present in feedstock F (e.g., in the form of a chlorinated polymer such as PVC). At least a portion of chlorine is removed in the form HCl during such an optional preheating. Furthermore, the feedstock F can be homogenized during preheating which results in a more uniform pyrolysis reaction in step b).

[0081] 30

[0082] Next, said feedstock F is converted in step b) by a first pyrolysis reaction in a first pyrolysis reactor PR1 to a reaction product RP1, said reaction product RP1 comprising a gas stream GS.

[0083] The feedstock F (optionally pretreated feedstock F) is inserted into the first pyrolysis reactor PR1 using a dosing unit 35 such as for example a screw or an extruder or a rotary valve or a pneumatic conveyor or a liquid injector. Next, the feedstock is heated in the pyrolysis reactor to a temperature in the range of from 400 to about 600 °C and a pressure in the range of from about 0.5 to about 2 bar(abs), more preferably in the range of from 0.9 bar to about 1.5 bar(abs). 240462WO01

[0084] 8

[0085] Pyrolysis processes as such are known. They are described, e.g., in EP 0713906 A1, WO 95 / 03375 A1 and Jörg Woidasky, Ullmanns Encyclopedia of Industrial Chemistry, chapter 5.2.1 “Pyrolysis”, pages 15-17, 2020 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim (DOI: 10.1002 / 14356007.a21_057.pub2).

[0086] 5 The pyrolysis reactor is preferably selected from the group comprising fluidized bed reactors, moving bed reactors, entrained flow reactors, stirred tank reactors, rotary kiln reactor and reactors comprising a reactor chamber and a rotation mechanism. More preferably, the first pyrolysis reactor PR1 comprises a reactor chamber and a rotation mechanism. Said rotation mechanism can be for example conveyor screws, conveyor double screws, kneaders, flu- idization units, preferably radially extending fluidization units, and combinations thereof. More preferably the first py-10 rolysis reactor PR1 is selected from reactors comprising a reactor chamber and a rotation mechanism, wherein said rotation mechanism is selected from the group comprising or preferably consisting of conveyor screws, conveyor double screws, kneaders, fluidization units, preferably radially extending fluidization units, and combinations thereof. Preferably, the pyrolysis is performed in the pyrolysis reactor under an inert atmosphere exempt of oxygen or air.

[0087] 15 The first pyrolysis reaction in the first pyrolysis reactor PR1 results in a reaction product RP1, said reaction product RP1 comprising a gas stream GS, and a solid residue SR (Figures 1 to 4). Preferably, the reaction product RP1 com- prises 5 to 45 wt.-% of gas stream GS, more preferably 15 to 35 wt.-% gas stream GS and most preferably 20 to 30 wt.-% gas stream GS.

[0088] 20 Next, said gas stream GS is separated from said reaction product RP1 in a separation unit SU, preferably by a method selected from the group comprising or more preferably consisting of condensation, extraction, adsorption and combinations thereof. Said gas stream GS is preferably separated from said reaction product RP1 in a separation unit SU. More preferably, said condensation is conducted in two or more, preferably three steps in said separation unit SU. The gas stream GS comprises all components of the reaction product RP1 which are volatile at the tempera-25 ture of condensation or volatile at the final (lowest) temperature of condensation in case the condensation is con- ducted in more than steps. The portion of said reaction product PR1 which is condensed in said separation unit SU is denoted pyrolysis oil PO (Figures 1 to 4). Said pyrolysis oil PO can be for example use as a fuel, a feedstock for pro- duction of synthesis gas in a partial oxidation unit or converted into olefins and / or C6−C8 aromatic hydrocarbons in a cracking unit such as a steam cracking unit or a fluid catalytic cracking unit.

[0089] 30

[0090] The temperature of the gas stream GS when leaving the condensation unit preferably ranges from 0 to 100 °C, more preferably 10 to 70 °C and most preferably 20 to 60 °C.

[0091] The gas stream GS comprises C1−C4 alkanes and hydrogen, and at least one further gas, said at least one further 35 gas selected from the group comprising CO, CO2, H2O, nitrogen and sulfur. “Nitrogen” and “sulfur” are comprised in gas stream GS for example as NH3and H2S. 240462WO01

[0092] 9

[0093] Gas stream GS composition ranges are given below. The values for the individual components may be combined in any combination and preferably result in 100 Vol.-% or less of the overall composition of gas stream GS (because other and / or further components such as CO2and / or H2S can be present in gas stream GS).

[0094] 5 The gas stream GS preferably comprises methane in a concentration of 0.5 to 55 Vol.-%, more preferably 1 to 50 Vol.-% and most preferably 2 to 40 Vol.-%.

[0095] The gas stream GS preferably comprises ethane in a concentration of 0.5 to 20 Vol.-%, more preferably 1 to 15 Vol.- % and most preferably 2 to 12 Vol.-%.

[0096] 10

[0097] The gas stream GS preferably comprises propane in a concentration of 0.25 to 15 Vol.-%, more preferably 0.5 to 12 Vol.-% and most preferably 1 to 10 Vol.-%.

[0098] The gas stream GS preferably comprises butanes in a concentration of 0.1 to 15 Vol.-%, more preferably 0.25 to 15 12 Vol.-% and most preferably 0.5 to 10 Vol.-%.

[0099] The gas stream GS preferably comprises hydrogen in a concentration of 0.5 to 50 Vol.-%, more preferably 1 to 40 Vol.-% and most preferably 2 to 35 Vol.-%.

[0100] 20 More preferably, gas stream GS comprises 1 to 90 Vol.-% C1−C4 alkanes and hydrogen in a concentration of 0.5 to 50 Vol.-%.

[0101] The gas stream GS preferably comprises CO in a concentration of 0.1 to 25 Vol.-%, more preferably 0.25 to 20 Vol.- % and most preferably 0.5 to 15 Vol.-%.

[0102] 25

[0103] The gas stream GS preferably comprises nitrogen in a concentration of 0.001 to 2.0 Vol.-%, more preferably 0.002 to 1.0 Vol.-% and most preferably 0.0025 to 0.5 Vol.-%.

[0104] Optionally, at least one gaseous co-feedstock COF is provided.

[0105] 30

[0106] The optional at least one co-feedstock COF is selected from the group comprising or preferably consisting of natural gas, synthetic methane, bio-methane, industrial off gas, biogas, flare gas, sewage gas, hydrogen from an external source, hydrogen from a gaseous internal recycle stream RF from second pyrolysis reaction in the second pyrolysis reactor PR2 and mixtures thereof.

[0107] 35

[0108] The gaseous internal recycle stream RF from second pyrolysis reaction in the second pyrolysis reactor PR2 is re- ferred in Figure 4 also to “1stCOF”. The optional at least one co-feedstock COF selected from the group comprising 240462WO01

[0109] 10

[0110] or preferably consisting of natural gas, synthetic methane, bio-methane, industrial off gas, biogas, flare gas, sewage gas, hydrogen from an external source and mixtures thereof is / are referred in Figure 4 also to “2ndCOF”.

[0111] Industrial off gas is preferably selected from the group comprising off gas from a steam cracking process, off gas 5 from a synthesis gas plant, off gas from a fluid catalytic cracking process, off gas from crude oil distillation, off gas from a resid fluid catalytic cracking process, off gas from a coking process, off gas from a hydrocracking process, off gas from a catalytic reformer, and combinations thereof.

[0112] Preferably, the optional at least one co-feedstock COF comprises gaseous internal recycle stream REF from second 10 pyrolysis reaction in the second pyrolysis reactor PR2.

[0113] Next, the gas stream GS is converted in step e) by a second pyrolysis reaction in a second pyrolysis reactor PR2 into hydrogen H and granular pyrolytic carbon GPC.

[0114] 15 The following abbreviations for feedstocks are used herein:

[0115] gas stream GS gaseous mixture, separated in step c) from reaction product PR

[0116] gas stream COF gaseous stream optionally provided in step d)

[0117] gas stream RF gaseous internal recycle stream from second pyrolysis reaction in a second pyrolysis reactor PR2

[0118] 20 total feed gas stream TF sum of all gas streams fed in step e) into the second pyrolysis reactor PR2

[0119] Figure 1 shows an aspect of the process without any co-feedstock COF, Figure 2 shows an aspect of the process in which the product hydrogen stream H is divided into an optional hydrogen separation unit HSU into an internal recy- cle hydrogen stream RF as co-feedstock COF and into a product hydrogen stream H´ (Figure 2a) or the product hy-25 drogen stream H is divided before an optional hydrogen separation unit HSU into an internal recycle hydrogen stream RF as co-feedstock COF and into a product hydrogen stream H entering the HSU (Figure 2b). Alternatively, the hydrogen stream H is divided both before and in an optional hydrogen separation unit HSU into a first and sec- ond internal recycle hydrogen stream RF as co-feedstock COF (Figure 2c). Figure 3 shows an aspect of the process in which an (external) co-feedstock COF is fed into the second pyrolysis reactor PR2. Figure 4 shows another aspect 30 of the process in which the product hydrogen stream H is divided into an optional hydrogen separation unit HSU into an internal recycle hydrogen stream RF as co-feedstock COF (“1stCoF”) and into a product hydrogen stream H´ and wherein at least one further (external) co-feedstock COF (“2ndCOF”) is fed into the second pyrolysis reactor PR2; additionally or alternatively the product hydrogen stream H is divided before an optional hydrogen separation unit HSU into an internal recycle hydrogen stream RF as co-feedstock COF and into a product hydrogen stream H enter-35 ing the HSU (Figure 4b). 240462WO01

[0120] 11

[0121] Preferably, said second pyrolysis reaction is a moving bed process (for example disclosed in US 2982622, WO 2019 / 145279, and WO 2020 / 200522), fluidized bed process, (for example disclosed in WO2020118417 and US20220185664) or fixed bed (catalytic) processes (for example disclosed in WO 2022043773 A1 and US 20040118047 A1).

[0122] 5

[0123] Most preferably, said second pyrolysis reaction is a moving bed process and the second pyrolysis reactor PR2 is a moving bed reactor. Carbon formed during step e) is deposited onto the particles (“solid granules”) of the bed mate- rial whereby undesired fouling by said carbon is suppressed. The bed material is purged from said second pyrolysis reactor PR2 regularly (in contrast to bed material in fluidized bed or fixed bed reactors).

[0124] 10

[0125] The pyrolysis process is preferably heated electrically, even more preferably by resistive heating (Joule heating) of the bed material (“substrate material”) as described for example in US 2982622, WO 2019 / 145279, and WO 2020 / 200522. More preferably, the second pyrolysis reactor PR2 is heated electrically with at least partially electricity from a renewable source. The renewable source is preferably selected from wind energy, solar energy, tidal energy, 15 nuclear energy, hydro energy, and mixtures thereof.

[0126] Preferably, the second pyrolysis reaction in step e) utilizes gas stream GS and at least one optional co-feed COF and is most preferably conducted in a moving, fluidized or fixed bed reactor, particularly preferred in a moving bed reac- tor, wherein the bed contains as bed material (also referred to as “substrates”) preferably carbon materials, ceramics, 20 and a mixture thereof, preferably at temperatures (in the second pyrolysis reactor PR2 during step e)) ranging from 1000 to 1600 °C, more preferably ranging from 1100 to 1500 °C, most preferably ranging from 1150 to 1450 °C, and at pressures ranging from 1 to 100 bar, preferably from 2.5 to 50 bar.

[0127] Bed material is purposely added in step e). Thereby, fouling in the second pyrolysis reactor PR2 caused by formation 25 of carbon is suppressed. The purposedly in step e) added bed material serves as a substrate onto which said carbon is deposited after formation in a controlled manner. Uncontrolled deposition of carbon, e.g. on the inner walls of the second pyrolysis reactor and / or the least one outlet of said reactor. Furthermore, said purposedly added bed material enables formation of granular pyrolytic carbon GPC, which is beside hydrogen the second desired product of the pro- cess according to the present invention.

[0128] 30

[0129] The bed material, also called “solid” or “carrier” or ”substrate”, is preferably a granular material. The purposedly added bed material preferably has an average particle size of 1 to 10 mm, more preferably 3 to 8 mm (determined by sieving with sieves having defined mesh sizes). Furthermore, the bed material purposely added in step e) is prefera- bly essentially free of metal(s), more preferably free of catalytically active metals such as calcium, zirconium, noble-35 metals, and nickel. 240462WO01

[0130] 12

[0131] The preferred bed material is a carbon-containing bed material, for example calcined petcoke (CPC) or pyrolytic car- bon obtained in a methane pyrolysis itself. The bed material consists of solid granules. The carbon content is prefera- bly in the range of 70 to 99 wt.-%, more preferably 90 to 99.9 wt.-%, more preferably 99 to 99.95 wt.-%, even more preferably 99 to 99.99 wt.-%. The oxygen content is preferably in the range of 20 to 1 wt.-%, more preferably 5 to 0.5 5 wt.-%, more preferably 1 to 0.1 wt.-%, even more preferably 0.5 to 0.001 wt.-%.

[0132] The ash content, in particular Fe, Ni, Ca, Si, Al, Cr, K, Mg, Mn, Pb, V and Zn, is preferably in the range 20 to 0 wt.-%, more preferably 5 to 0 wt.%, more preferably 1 to 0 wt.-%, even more preferably 0.5 wt.% to 0 wt.%. Most preferably, the bed material purposely added in step e) is essentially free of metal(s), particularly essentially free of catalytically 10 active metals such as calcium, zirconium, noble-metals, and nickel. The sulfur content is preferably in the range 5 to 0.5 wt.-%, more preferably 0.5 to 0.1 wt.-%, more preferably 0.1 to 0.01 wt.-%, even more preferably 0.01 to 0.0001 wt.-%. The chlorine content is preferably in the range 1 to 0.1 wt.%, more preferably 0.1 to 0.01 wt.-%, even more preferably 0.01 to 0.00001 wt.-%. The elemental composition can be determined by standard methods such as ICP- AES.

[0133] 15

[0134] The BET surface area of the substrate is preferably between 0.1 and 100 m2 / g, preferably 0.1 and 50 m2 / g, in partic- ular 0.1 to 30 m2 / g (measured by Hg porosimetry, DIN 66133).

[0135] Preferably, the real density of the substrate is in the range of 1.5 to 2.5 g / cm3(determined by ISO 8004). Preferably, 20 the bulk density of the substrate is in the range of 0.5 to 1.5 g / cm3(determined by DIN 51705:2001-06).

[0136] Most preferably, the substrate is guided in form of a moving bed through the second pyrolysis reactor PR2, with the gas stream GS and the optional at least one co-feedstock COF being passed advantageously in countercurrent to the substrate. For this purpose, the reaction chamber of the second pyrolysis reactor PR2 is preferably rationally de-25 signed as a vertical reactor, which means that the movement of the moving bed is gravity driven. Flow through the moving bed is taking place, advantageously, homogeneously, and uniformly (see for example WO 2013 / 004398, WO 2019 / 145279, and WO 2020 / 200522). The gas stream GS, optionally together with at least one co-feedstock COF is / are preferably introduced via the bottom of the second pyrolysis reactor PR2, preferably having a temperature of - 10 to 200 °C. The substrate is preferably introduced via the top of the second pyrolysis reactor PR2, preferably hav-30 ing a temperature of -10 to 200 °C. Hydrogen, preferably as a hydrogen containing stream, is preferably taken off via the top of the second pyrolysis reactor PR2, preferably having a temperature of 10 to 200 °C. The pyrolytic carbon, preferably deposited on the substrate, is preferably taken off as a granular pyrolytic carbon GPC via the bottom of the second pyrolysis reactor PR2, preferably having a temperature of 10 to 200 °C. The discharged pyrolytic carbon GPC is preferably at least partly recycled and introduced into the reactor again using it as substrate for the moving 35 bed. As a result, a continuous process of the moving bed is achieved. 240462WO01

[0137] 13

[0138] The flow velocity of the substrate is advantageously in the range of 0.005 to 6.0 cm / s, more preferably 0.005 to 0.5 cm / s. The flow velocity of the gas flow is advantageously in the range of 0.025 to 10 m / s, more preferably 0.025 to 2 m / s. The gas residence time in the reactor is advantageously between 0.1 and 50 s, preferably between 1 and 20 s. The residence time of the substrate is preferably between 0.1 and 15 hours, preferably between 1 and 10 hours and 5 more preferably between 2 and 8 hours.

[0139] Preferably, granular pyrolytic carbon GPC has an average particle size of 0.5 mm (D10) to 20 mm (D90), preferably 1mm (D10) to 15 mm (D90) (determined by sieving using sieves having defined mesh sizes).

[0140] 10 Typically, the real density of the deposited granular pyrolytic carbon GPC produced via the described methane pyrol- ysis process is in the range of 1.5 to 2.5 g / cm3, preferably 2.0 to 2.3 g / cm3(determined by ISO 8004). Typically, the bulk density of the granular pyrolytic carbon GPC is in the range of 0.5 to 1.5 g / cm3, more preferably 0.7 to 1.3 g / cm3(determined by DIN 51705:2001-06).

[0141] 15 Typically, the porosity of the granular pyrolytic carbon is between 0 to 15 %, preferably 0.2 to 10 %, most preferably 0.2 to 5 % (determined by Hg porosimetry, DIN66133).

[0142] Preferably, the granular pyrolytic carbon GPC formed in step e) has a BET surface area of 0.001 to 20 m2 / g, prefera- bly 0.001 to 10 m2 / g, even more preferably 0.05 to 5 m2 / g (determined by Hg porosimetry, DIN66133). Accordingly, 20 the granular pyrolytic carbon GPC formed in step e) has a reduced tendency to adsorb or absorb undesired heteroa- toms compared to nano-carbon formed by plasma pyrolysis e.g., at temperatures of 1500 to 3500 °C which have a much higher BET surface area of for example 50 to more than 1000 m2 / g.

[0143] Preferably, the granular pyrolytic carbon GPC comprises preferably less than 5 wt.-%, more preferably less than 25 1 wt.-% and most preferably less than 0.1 wt.-% impurities of other chemical elements than carbon. Typically, the ash content of the granular pyrolytic carbon GBC is in the range of 0.001 to 1 wt.-%, preferably 0.01 to 0.2 wt.-%. Typi- cally, the carbon content in the granular pyrolytic carbon GBC is in the range of 98 to 100 wt.-%, more preferably 99.5 to 100 wt.-%, even more 99.75 to 100 wt.-%, even more 99.9 to 100 wt.-%. The elemental composition can be determined by standard methods such as ICP-AES.

[0144] 30

[0145] Preferably, gas stream GS1 has a temperature of 0 to 100 °C, more preferably 10 to 70 °C and most preferably 20 to 70 °C when fed into the second pyrolysis reactor PR2 in step d).

[0146] More preferably, the gas stream GS has a similar temperature after separation from said reaction product RP1 in 35 step c) and when fed into the second pyrolysis reactor PR2 in step e). Even more preferably, the gas stream GS has a temperature within a margin of + / - 20 %, preferably + / - 10 % after separation from said reaction product RP1 in 240462WO01

[0147] 14

[0148] step c) and when fed into the second pyrolysis reactor PR2 in step e). Most preferably, no heating or cooling of the gas stream GS is required between step c) and step e).

[0149] Preferably, gas stream GS1 has a pressure of 1 to 15 bar(abs.) when fed into the second pyrolysis reactor PR2. Op- 5 tionally, the gas stream GS1 can be compressed, e.g., in a screw compressor, to obtain the desired pressure.

[0150] The second pyrolysis reactor PR2 is preferably not a plasma-type reactor. Such plasma-type reactors are not suited as second pyrolysis reactor PR2 for the process according to the present invention, because of several reasons: - the residence time of gas stream GS in the second pyrolysis reactor PR2 during step e) is too short for the 10 desired conversion of said gas stream GS into hydrogen H,

[0151] - the conversion of hydrocarbons in such plasma-type reactors produces nano-carbon which is not desired as the carbon product of the process according to the present invention,

[0152] - due to the preheating of the feedstock in processes utilizing plasma-type reactors in a preheating section up- stream of the plasma-type reactor and the multi-component composition of gas stream GS1, soot formation in 15 the preheating section is likely. Such soot formation is undesired because of fouling associated and a reduc- tion of the hydrogen yield.

[0153] Preferably, at least one co-feedstock COF is / are fed into the second pyrolysis reactor PR2 in step e) together with gas stream GS, preferably at least one co-feedstock COF containing hydrogen.

[0154] 20

[0155] Preferably, the total feed gas stream TF for the second pyrolysis reactor is adjusted by the co-feedstock COF to a fixed molar ratio of H2 / C1+, the so-called operation point. The operating point enables an optimal heat integration and is dependent on the hydrocarbon concentration, the substrate used and the deposition rate of the solid carbon.

[0156] 25 The carbon deposition rate of solid pyrolytic carbon is preferably 0.1 to 15 wt.-%, more preferably 2 to 12 wt.-%, even more preferably 3 to 10 wt.-%, even more preferably 4 to 9 wt.%, even more preferably 4 to 8 wt.-%. The definition of the carbon deposition rate, sometimes also referred to as carbon growth rate, depends on the reactor type and is defined in the following:

[0157] 30 The symbols and indices used are shown in Table 1. 240462WO01

[0158] 15

[0159] Table 1. Symbols and indices used for describing carbon deposition and growth rates.

[0160] Symbol Description

[0161] ^^^^,ௗ^^^^^௧^^^ Carbon deposition rate [molC / s]

[0162] ^^^^ுସ,^ Molar flow [molC / s]

[0163] ^^ Conversion rate [-]

[0164] ^^^ ^,ௗ^^^^^௧^^^ Carbon deposition rate [g / s]

[0165] ^^^ Molar mass [g / mol]

[0166] ^^^^ Carbon deposition [g / g]

[0167] Δ^^^ Carbon mass increase [g]

[0168] ^^^ Carbon mass [g]

[0169] ^^^^^ Carbon deposition rate in [g / g*s]

[0170] τ Time unit [s]

[0171] ^^^^^^^ Carbon deposition rate (per reference time unit) [-] or in [wt.%]

[0172] V Reactor volume [m3]

[0173] Indices Description

[0174] 0 Particle before pyrolysis or state feed gas

[0175] 1 Particle after pyrolysis or state in pyrolysis gas

[0176] in Reactor inlet

[0177] ref Reference (e.g. time unit)

[0178] The carbon deposition rate in [mol,C / s] results from the molar flow of CH4in the feed gas and the conversion rate:

[0179]

[0180] 5

[0181] Considering the molar mass of atomic carbon leads to the carbon deposition rate in [g,C / s]:

[0182] ^^^ ^,ௗ^^^^^௧^^^ = ^^^ ^,ௗ^^^^^௧^^^ ⋅ ^^^

[0183]

[0184] The CH4conversion rate is calculated using the molar flow of CH4in the feed and in the pyrolysis gas:

[0185] 10

[0186] ^ ^^^

[0187] ^ = ^ுସ,^ − ^^^^ுସ,^ ^^^^ுସ,^

[0188]

[0189] ^^^ = 1 −^ுସ,^ ^^^ ^ுସ,^

[0190] The carbon deposition in [g / g] is defined as: 240462WO01

[0191] 16

[0192] ^^^^ = Δ^^^ 4^^^

[0193] The carbon deposition rate in [g / (g*s)] follows from the initial mass and the carbon deposition rate in [mol,C / s]:

[0194]

[0195] 5 The total increase in carbon mass depends on the residence time of the carrier within the pyrolysis zone:

[0196] Δ^^^ = ^^^ ^,ௗ^^^^^௧^^^ ⋅ τ

[0197]

[0198] Considering the reactor volume ^^ and the reactor type specific reference residence time leads to the carbon deposi- tion rate per reference time unit in [-]:

[0199] 10

[0200]

[0201] The carbon deposition rate per reference time unit can also be expressed in [wt.-%] as follows:

[0202]

[0203] 15 The reactor specific reference residence time is defined as follows:

[0204] • Batch / Fixed bed: ^^ = total pyrolysis time^^^

[0205] • Moving bed: ^^ = mean residence time of carrier particles in the pyrolysis zone^^^

[0206] • Fluidized bed: ^^ = mean residence time of carrier particles in the pyrolysis zone^^^

[0207] Reference mass in [g]:

[0208] 20 • Batch / Fixed bed: ^^ = initial carrier mass in the reactor^

[0209] • Moving bed: ^^ = ∙ ^^ with the reactor inlet mass flow ^ in [g / s]

[0210]

[0211] ^ ^^^ ^^^^^

[0212]

[0213] ^^ ^^ • Fluidized bed: ^^ = ^^^ ∙ ^^ with the reactor inlet mass flow ^^^ in [g / s]^ ^^^ ^^^^^^^ ^^^^^^^

[0214] Depending on the available instrumentation and analysis methods, different ways for the practical application of the 25 described theoretical framework for the calculation of ^^^^ exist. It is important to note that the specific material^^^

[0215] property must be measured before the pyrolysis (index “0”) and after a pyrolysis time of ^^ (index “1”).^^^ 240462WO01

[0216] 17

[0217] Exemplary ways of application:

[0218] • Using the Sauter mean diameter of the particle size distribution and the measured real density from heliumor xylene pycnometer:

[0219] ^^ ^^

[0220]

[0221] ,5

[0222] • Using a reference volume ^^ which contains the particle mass ^^ to determine the bulk density:^^^ ^௨^^,^,^

[0223] ^^ ^^

[0224]

[0225] , , ,

[0226] • Using the measured or calculated initial carrier weight ^^ , using gas analytics for the calculation of conver-^

[0227] sion rate, using the measured of calculated molar flow rates and applying the detailed formulas given 10 above.

[0228] Moving bed: The solid carbon mass from hydrocarbon pyrolysis deposited on one solid granule in one pass through the reactor divided by the mass of the said one solid granule before entering the reactor. The mass of the said solid particle before and after the pyrolysis is calculated by the Sauter mean diameter of the particle size distribution and 15 the real density of the used granule. The reference residence time according to equations 7 to 8 is preferably be- tween 0.1 and 15 h, preferably between 1 and 10 h and more preferably between 2 and 8 h.

[0229] Fixed bed: The solid carbon mass from hydrocarbon pyrolysis deposited on one solid granule during its residence time in the reactor divided by the mass of the said one solid granule before entering the reactor. The mass of the said 20 solid particle before and after the pyrolysis is calculated by the Sauter mean diameter of the particle size distribution and the real density of the used granule. The reference residence time according to equations 7 to 8 is preferably 0.1 to 90 h, more preferably 0.25 to 50 h, more preferably 0.5 to 25 h and even more preferably 1.0 to 10 h.

[0230] Fluidized bed: The solid carbon mass from hydrocarbon pyrolysis deposited on one solid granule during one inner 25 circulation through the reactor divided by the mass of the said one solid granule before entering the reactor. The mass of the said solid particle before and after the pyrolysis is calculated by the Sauter mean diameter of the particle size distribution and the real density of the used granule. In a fluidized bed, one particle can circulate multiple times through the reactor during its residence time inside the reactor. The reference residence time according to equations 240462WO01

[0231] 18

[0232] 7 to 8 is preferably 0.1 to 90 h, more preferably 0.25 to 50 h, more preferably 0.5 to 25 h and even more preferably 1.0 to 10 h.

[0233] Beside the temperature and the pressure, the carbon deposition rate is preferably be controlled by diluting the gas 5 stream GS with hydrogen via a co-feedstock COF: The molar ratio of H2 / C1+of the total feed stream TF for the sec- ond pyrolysis, the gas stream GS and at least one co-feedstock COF, is preferably ranging from 0.1 to 25, more pref- erably from 0.5 to 10, even more preferably from 1 to 8. The molar ratio of H2 / C1+of the total feed stream TF for the second pyrolysis is optionally increased to reduce the carbon deposition rate for the pyrolysis reaction of the gas stream GS. Thereby, undesired fouling can be even more suppressed.

[0234] 10

[0235] The carbon deposition rate is preferably also controlled by the conversion rate of the second pyrolysis reaction, said conversion rate preferably ranges from 25 to 90 %, more preferably from 30 to 85 %, even more preferably from 40 to 80 %, most preferably from 50 to 80 % (based on the total feed stream TF).

[0236] 15 There are several process layouts how to realize said H2 / C1+, particularly H2 / C1-C4feed molar ratio. Without exclud- ing further options, preferred layouts or combinations thereof (see Figure 2c, 4b) are:

[0237] - hydrogen containing gas stream from the second pyrolysis (types of gaseous internal recycle stream RF from second pyrolysis reaction in the second pyrolysis reactor PR2):

[0238] o direct internal gas recycle: a portion of the product hydrogen stream H is recycled without any purification 20 steps; gas streams may or may not be cooled or heated (see Figure 2b),

[0239] o recycle after purification unit: the hydrogen depleted gas stream after any purification or gas separation unit is recycled to the reactor, while a fraction is purged (see Figure 2a),

[0240] o gas streams employed for pneumatic transport of solids are recycled to the reactor,

[0241] - hydrogen containing gas streams from different processes or other sources are mixed to the gas stream GS (see Fig-25 ure 3).

[0242] Preferably, a direct internal recycle of the product hydrogen stream H is used as gaseous internal recycle stream RF, that means, a portion of the raw product hydrogen stream H is recycled without any purification steps (see Figure 2b). Said recycled gaseous internal recycle stream RF may or may not be cooled, heated and / or compressed. 30

[0243] The product hydrogen stream H leaving the reaction chamber preferably enters a separation unit. This separation unit typically includes a valve, a flow meter, and a meter to determine the H2concentration.

[0244] Preferably, 20 to 90 Vol.-% of the product hydrogen stream H is separated and recycled to the reaction chamber, 35 more preferably 30 to 85 Vol.- %, more preferably 40 to 85 Vol.-%, even more preferably 50 to 80 Vol.-%. 240462WO01

[0245] 19

[0246] The recycle stream RF is mixed with the gas stream GS inside or outside the reaction chamber. Before mixing, the temperature of the recycle stream RF is preferably between 10 and 200 °C, even more preferably between 15 and 150 °C and in particular between 20 and 100 °C. Preferably, the gas stream GS and the recycle stream RF are mixed before entering the rection chamber, outside of the reactor. Alternatively, the streams are separately intro- 5 duced into the reaction chamber.

[0247] Therefore, the total feed gas stream TF of the second pyrolysis contains at least two feed streams: (i) gas stream GS and (ii) a co-feedstock COF, preferably a recycle gas stream RF.

[0248] 10 Depending on the reaction conditions of the second pyrolysis, the content of the product hydrogen stream H (related to the total volume of the product hydrogen stream H) is preferably:

[0249] (i) hydrogen preferably between 30 and 99 Vol.-%, more preferably between 50 and 98 Vol.-%, and in particular be- tween 60 and 98 Vol.-%,

[0250] (ii) methane preferably between 1 and 60 Vol.-%, more preferably between 2 and 40 Vol.-% and in particular between 2 15 and 30 Vol.-%,

[0251] (iii) the sum of the contents of all C2+hydrocarbon components comprising e.g. C2H6, C2H4, C2H2, C3H8, C3H6, C3H4, C4H8, C4H6, C6H6, C7H8, C8H10preferably between 0 and 1 mol-%, more preferably between 0 and 0.5 mol-% and in particular between 0 and 0.1 mol-%,

[0252] (iv) nitrogen preferably between 0 and 20 Vol.-%, more preferably between 0 and 10 Vol.-% and in particular between 0 20 and 5 Vol.-%, carbon monoxide preferably between 0 and 2 Vol.-%, more preferably between 0 and 1 Vol.-% and in particular between 0 and 0.5 Vol.-%, carbon dioxide preferably between 0 and 2 Vol.-%, more preferably between 0 and 1 Vol.-% and in particular between 0 and 0.5 Vol.-% and the water preferably between 0 and 2 Vol.-%, more preferably between 0 and 1 Vol.-% and in particular between 0 and 0.5 Vol.-%.

[0253] 25 Optionally, at least one co-feedstock COF is co-feed in step e) into the second pyrolysis reactor PR2. Said at least one co-feedstock COF can be hydrogen from an external source and may be required to reach and maintain the de- sired operation point of the second pyrolysis reaction in the second pyrolysis reactor PR2. The external source for optional hydrogen from external source as at least one co-feedstock COF is selected from the group comprising or preferably consisting of hydrogen formed by electrolysis of water, hydrogen comprised in natural gas, hydrogen com-30 prised on biomethane, hydrogen comprised in flare gas, hydrogen comprised in off gases, hydrogen comprised in hydrocarbon cracking product streams, and combinations thereof. Most preferably, external source for optional hy- drogen from external source as at least one co-feedstock COF is hydrogen manufactured by water electrolysis using renewable energy wherein the renewable energy is selected from the group comprising or preferably consisting of wind energy, solar energy, tidal energy, nuclear energy, hydro energy, and mixtures thereof.

[0254] 35

[0255] Due to the fact that the H2 / C1+ ratio of the total feed gas stream TF, the feed stream mixture of the gas stream GS and at least one co-feedstock COF, could be controlled by adjusting the co-feedstock, a broad concentration range of 240462WO01

[0256] 20

[0257] hydrocarbons in the gas stream GS can be converted in step e) while maintaining desired process conditions and operation point of the second pyrolysis reaction in the second pyrolysis reactor PR2 resulting in high hydrogen yield and granular pyrolytic carbon GPC having the desired properties and purity.

[0258] 5 Preferably, the hydrogen and / or hydrocarbon concentration of the gas stream GS is measured before feeding it into the second pyrolysis reactor PR2. Depending on the difference of said concentration to the operation point, the gas stream COF, preferably the recycle gas stream RF is / are increased or decreased.

[0259] The chemical plant for manufacture of hydrogen from waste comprises:

[0260] 10 a) a first pyrolysis reactor PR1,

[0261] b) a gas separation unit SU, said gas separation unit SU downstream of and fluidically connected to the first py- rolysis reactor PR1,

[0262] c) a second pyrolysis reactor PR2, said second pyrolysis reactor PR2 downstream of and fluidically connected to the gas separation unit SU,

[0263] 15 wherein said second pyrolysis reactor PR2 selected from the group consisting of moving bed reactor, fluidized bed reactor and fixed bed reactor.

[0264] Most preferably, said second pyrolysis reactor PR2 is selected from the group consisting of moving bed reactor, fluid- ized bed reactor and fixed bed reactor, and is not a plasma reactor.

[0265] 20

[0266] The term “downstream of” is defined herein in respect to a succession of unit operations as located next to each other and on the side which is in the flow direction of fluids passing said succession of unit operations.

[0267] The term “fluidically connected to” in respect to two or more units is defined herein that a fluid such as a particulate 25 solid, liquids, gases, and mixtures thereof can flow from one of such unit to the other such unit and flow through and / or along such an analytical unit. Two units “fluidically connected to” each other are for example connected by one or more pipes which each other or pumps, compressors and the like.

[0268] The first pyrolysis reactor PR1 is selected from the group comprising or preferably consisting of comprising fluidized 30 bed reactors, moving bed reactors, entrained flow reactors, stirred tank reactors, rotary kiln reactor and reactors comprising a reactor chamber and a rotation mechanism.

[0269] More preferably, the first pyrolysis reactor PR1 comprises a reactor chamber and a rotation mechanism. More prefer- ably, said rotation mechanism is selected from the group comprising or preferably consisting of conveyor screws, 35 conveyor double screws, fluidization units, preferably radially extending fluidization units, and combinations thereof.

[0270] The peripheral speed of the extending fluidization units during operation of the pyrolysis unit PU1 preferably ranges 240462WO01

[0271] 21

[0272] from 15 to 135 m / s, more preferably from 35 to 85 m / s. The residence time for the feed stream S1 inside the pyroly- sis unit PU2 preferably range from 2.5 to 40 min.

[0273] Preferably, the gas separation unit SU is selected from the group comprising or preferably consisting of flash drums, 5 strippers, distillation columns, quench columns, heat exchangers with cooled surfaces to condense, and combina- tions thereof.

[0274] Preferably, the second pyrolysis reactor PR2 is selected from the group comprising or preferably consisting of mov- ing bed reactor, fluidized bed reactor and fixed bed reactor. More preferably, the second pyrolysis reactor PR2 is a 10 moving bed reactor.

[0275] Optionally, the chemical plant further comprises a means M for removing at least one member of the group compris- ing or consisting of NH3, NOx, H2S, SOx, HCl, HBr from the gas stream GS separated in the gas separation unit SU, said means M downstream of the gas separation unit SU and directly or indirectly fluidically connected to the gas 15 separation unit SU, and upstream of the second pyrolysis reactor PR2 and directly or indirectly fluidically connected to the second pyrolysis reactor PR2.

[0276] A further aspect of the present invention concerns the use of a gas stream GS manufacture by the steps a) providing a feedstock F, said feedstock F comprising waste,

[0277] 20 b) converting said feedstock F by a first pyrolysis reaction in a first pyrolysis reactor PR1 to a reaction product RP1, said reaction product RP1 comprising a gas stream GS, and

[0278] c) separating said gas stream GS from said reaction product RP1 in a gas separation unit SU,

[0279] as a (co-)feedstock for a second pyrolysis reaction in a second pyrolysis reactor PR2, whereby said gas stream GS is converted into hydrogen and granular pyrolytic carbon.

[0280] 25

[0281] The present invention is further illustrated by the following set of embodiments and combinations of embodiments resulting from the dependencies and back-references as indicated. In particular, it is noted that in each instance where a range of embodiments is mentioned, for example in the context of a term such as "The process of any of embodiments 1 to 3", every embodiment in this range is meant to be explicitly disclosed for the skilled person, i.e. the 30 wording of this term is to be understood by the skilled person as being synonymous to "the process of any of embodi- ments 1, 2 and 3". Further, it is explicitly noted that the following set of embodiments represents a suitably structured part of the general description directed to preferred aspects of the present invention, and thus, suitably supports the claims of the present invention.

[0282] 35 240462WO01

[0283] 22

[0284] Embodiments

[0285] 1. Process for manufacture of hydrogen from waste, the process comprising the steps

[0286] a) providing a feedstock F, said feedstock F comprising waste,

[0287] b) converting said feedstock F by a first pyrolysis reaction in a first pyrolysis reactor PR1 to a reaction 5 product RP1, said reaction product RP1 comprising a gas stream GS,

[0288] c) separating said gas stream GS from said reaction product RP1 in a gas separation unit SU, d) optionally providing a gaseous co-feedstock COF,

[0289] e) converting said gas stream GS and the gaseous co-feedstock COF optionally provided in step d) by a second pyrolysis reaction in a second pyrolysis reactor PR2 into hydrogen H and granular pyrolytic 10 carbon GPC, wherein the second pyrolysis reaction is conducted in a moving bed reactor, fluidized bed reactor or fixed bed reactor, wherein the temperature in the second pyrolysis reactor PR2 during step e) ranges from 1000 to 1600 °C, and wherein bed material is purposely added in step e).

[0290] 2. Process according to embodiment 1 wherein the feedstock F is selected from the group consisting of plastic 15 waste, bio waste and mixtures thereof.

[0291] 3. Process according to embodiment 2 wherein the plastic waste is selected from the group comprising or prefer- ably consisting of mixed plastic waste and end-of-life tires.

[0292] 20 4. Process according to any one of embodiments 1 to 3 wherein the waste comprises at least two members of the group comprising or preferably consisting of polyolefins polystyrene, copolymers comprising polystyrene, polyvinylchloride (PVC), polyvinylidene chloride (PVDC), polyamides (PA), polyurethanes (PU), polyesters, polycarbonate (PC), and rubbers.

[0293] 25 5. Process according to any one of embodiments 1 to 4 wherein the feedstock F is pretreated before step a).

[0294] 6. Process according to any one of embodiments 1 to 5 wherein the feedstock F is pretreated before step a) by a method selected from the group comprising or preferably consisting of sorting, comminution, preheating, sol- volysis, and combinations thereof.

[0295] 30

[0296] 7. Process according to any one of embodiments 1 to 6 wherein the first pyrolysis reaction in the first pyrolysis reactor PR1 in step b) is conducted in an inert atmosphere.

[0297] 8. Process according to any one of embodiments 1 to 7 wherein the temperature of the first pyrolysis reaction in 35 the first pyrolysis reactor PR1 in step b) ranges from 400 to 600 °C. 240462WO01

[0298] 23

[0299] 9. Process according to any one of embodiments 1 to 8 wherein the first pyrolysis reactor PR1 is selected from the group comprising or preferably consisting of comprising fluidized bed reactors, moving bed reactors, en- trained flow reactors, stirred tank reactors, rotary kiln reactor and reactors comprising a reactor chamber and a rotation mechanism

[0300] 5

[0301] 10. Process according to any one of embodiments 1 to 9 wherein gas stream GS is separated from the reaction product RP1 in step c) by a method selected from the group comprising or preferably consisting of condensa- tion, extraction, adsorption and combinations thereof.

[0302] 10 11. Process according to any one of embodiments 1 to 10 wherein the temperature of the gas stream GS after separation from said reaction product RP1 in step c) preferably ranges from 0 to 100 °C, more preferably from 10 to 70 °C and most preferably from 20 to 60 °C.

[0303] 12. Process according to any one of embodiments 1 to 11 wherein the concentration of the gas stream GS in the 15 reaction product RP1 ranges from 5 to 45 wt.-%.

[0304] 13. Process according to any one of embodiments 1 to 12 wherein the gas stream GS comprises C1−C4 alkanes.

[0305] 14. Process according to any one of embodiments 1 to 13 wherein the gas stream GS comprises 1 to 90 Vol.-% 20 C1−C4 alkanes.

[0306] 15. Process according to any one of embodiments 1 to 14 wherein the gas stream GS comprises 0.5 to 55 Vol.-% methane.

[0307] 25 16. Process according to any one of embodiments 1 to 15 wherein the gas stream GS comprises 0.5 to 20 Vol.-% ethane.

[0308] 17. Process according to any one of embodiments 1 to 16 wherein the gas stream GS comprises 0.25 to 15 Vol.- % propane.

[0309] 30

[0310] 18. Process according to any one of embodiments 1 to 17 wherein the gas stream GS comprises 0.1 to 15 Vol.-% butanes.

[0311] 19. Process according to any one of embodiments 1 to 18 wherein the gas stream GS comprises hydrogen in a 35 concentration of 0.5 to 50 Vol.-%. 240462WO01

[0312] 24

[0313] 20. Process according to any one of embodiments 1 to 19 wherein the gas stream GS comprises 1 to 90 Vol.-% C1−C4 alkanes and hydrogen in a concentration of 0.5 to 50 Vol.-%.

[0314] 21. Process according to any one of embodiments 1 to 20 wherein the gas stream GS further comprises at least 5 one member of the group consisting of CO, CO2, H2O, nitrogen and sulfur.

[0315] 22. Process according to any one of embodiments 1 to 21 wherein the concentration of CO in gas stream GS ranges from 0.1 to 25 Vol.-%.

[0316] 10 23. Process according to any one of embodiments 1 to 22 wherein the concentration of nitrogen in gas stream GS ranges from 0.001 to 2 Vol.-%.

[0317] 24. Process according to any one of embodiments 1 to 23 wherein at least one gaseous co-feedstock COF is pro- vided in step d).

[0318] 15

[0319] 25. Process according to any one of embodiments 1 to 24 wherein gaseous co-feedstock COF are provided in step d) and wherein said gaseous co-feedstock COF is selected from the group comprising or preferably con- sisting of hydrogen, natural gas, synthetic methane, bio-methane, industrial off gas, biogas, sewage gas and mixtures thereof.

[0320] 20

[0321] 26. Process according to any one of embodiments 1 to 25 wherein at least one gaseous co-feedstock COF is pro- vided in step d) and wherein said gaseous co-feedstock COF contains hydrogen.

[0322] 27. Process according to any one of embodiments 1 to 26 wherein the total feed gas stream TF for the second 25 pyrolysis reactor, the gas stream GS and at least one co-feedstock COF, is adjusted by the co-feedstock COF to a fixed molar ratio of H2 / C1+, to the operation point.

[0323] 28. Process according to any one of embodiments 1 to 27 wherein the hydrogen and / or hydrocarbon concentra- tion of the gas stream GS is measured before feeding it into the second pyrolysis reactor PR2 and wherein 30 the amount of at least one co-feedstock COF is increased or decreased depending on the difference of said concentration to the operation point.

[0324] 29. Process according to any one of embodiments 1 to 28 wherein the molar ratio of H2 / C1+of the total feed stream TF for the second pyrolysis, the gas stream GS and at least one co-feedstock COF, is preferably rang-35 ing from 0.1 to 25, more preferably from 0.5 to 10, even more preferably from 1 to 8. 240462WO01

[0325] 25

[0326] 30. Process according to any one of embodiments 1 to 29 wherein at least one gaseous co-feedstock COF is pro- vided in step d) and wherein a direct internal recycle of the hydrogen-containing product stream of the second pyrolysis reaction is used as said gaseous co-feedstock COF.

[0327] 5 31. Process according to any one of embodiments 1 to 30 wherein gas stream GS has a temperature of prefera- bly 0 to 100 °C more preferably 10 to 70 °C and most preferably 20 to 60 °C when fed into the second pyroly- sis reactor PR2 in step e).

[0328] 32. Process according to any one of embodiments 1 to 31 wherein gas stream GS has a temperature within a 10 margin of + / - 10 %, after separation from said reaction product RP1 in step c) and when fed into the second pyrolysis reactor PR2 in step e).

[0329] 33. Process according to any one of embodiments 1 to 32 wherein no heating or cooling of the gas stream GS is required between step c) and step e).

[0330] 15

[0331] 34. Process according to any one of embodiments 1 to 33 wherein gas stream GS has a pressure of 1 to 15 bar(abs.) when fed into the second pyrolysis reactor PR2.

[0332] 35. Process according to any one of embodiments 1 to 34 wherein the second pyrolysis reactor PR2 is not a 20 plasma reactor.

[0333] 36. Process according to any one of embodiments 1 to 35 wherein the second pyrolysis reactor PR2 used in step e) is a moving bed reactor.

[0334] 25 37. Process according to any one of embodiments 1 to 36 wherein the temperature in the second pyrolysis reac- tor PR2 during step e) ranges from 1000 to 1600 °C, more preferably from 1100 to 1500 °C, most preferably ranging from 1150 to 1450 °C.

[0335] 38. Process according to any one of embodiments 1 to 37 wherein the pressure in the second pyrolysis reactor 30 PR2 during step e) ranges from 1 to 100 bar, preferably from 2.5 to 50 bar.

[0336] 39. Process according to any one of embodiments 1 to 38 wherein the residence time of gas stream GS in the second pyrolysis reactor PR2 during step e) ranges from 0.5 to 1500 s.

[0337] 35 40. Process according to any one of embodiments 1 to 39 wherein the carbon deposition rate for the pyrolysis reaction of the gas stream GS is kept in a range of preferably 0.1 to 20 wt.-%, more preferably 1 to 15 %, more preferably 2 to 12 %, even more preferably 3 to 10 wt.-%, even more preferably 4 to 8 wt.-%. 240462WO01

[0338] 26

[0339] 41. Process according to any one of embodiments 1 to 40 wherein the molar ratio of H2 / C1+ of the total feed stream TF for the second pyrolysis is increased to reduce the carbon deposition rate for the pyrolysis reaction of the gas stream GS.

[0340] 5

[0341] 42. Process according to any one of embodiments 1 to 41 wherein the conversion rate of the second pyrolysis reaction range from 25 to 90 %, preferably from 30 to 85 %, more preferably from 40 to 80 %, most preferably from 50 to 80 % (based on the total feed stream TF).

[0342] 10 43. Process according to any one of embodiments 1 to 42 wherein the temperature of hydrogen H when leaving the second pyrolysis reactor PR2 after step e) has a temperature of 10 to 200 °C.

[0343] 44. Process according to any one of embodiments 1 to 43 wherein the temperature of granular pyrolytic carbon GPC when leaving the second pyrolysis reactor PR2 after step e) has a temperature of 10 to 200 °C.

[0344] 15

[0345] 45. Process according to any one of embodiments 1 to 44 wherein the purposely added bed material has an aver- age particle size of 1 to 10 mm, preferably 3 to 8 mm (determined by sieving with sieves having defined mesh sizes).

[0346] 20 46. Process according to and one of embodiments 1 to 45 wherein bed material is purposely added and wherein said purposely added bed material essentially free of metal(s).

[0347] 47. Process according to any one of embodiments 1 to 46 wherein the bed material has a BET surface area of 0.1 to 100 m2 / g, preferably 0.1 to 50 m2 / g, even more preferably 0.1 to 30 m2 / g (measured by Hg porosimetry, 25 DIN66133).

[0348] 48. Process according to any one of embodiments 1 to 47 wherein the bed material has a bulk density in the range of 0.5 to 1.5 g / cm3(determined by DIN 51705:2001-06).

[0349] 30 49. Process according to any one of embodiments 1 to 48 wherein carbon formed during step e) is deposited onto said bed material.

[0350] 50. Process according to any one of embodiments 1 to 49 wherein the granular pyrolytic carbon GPC has a BET surface area of 0.001 to 20 m2 / g, preferably 0.001 to 10 m2 / g, even more preferably 0.05 to 5 m2 / g (measured 35 by Hg porosimetry, DIN66133). 240462WO01

[0351] 27

[0352] 51. Process according to any one of embodiments 1 to 50 wherein granular pyrolytic carbon GPC has a bulk den- sity of the granular pyrolytic carbon GPC is in the range of 0.5 to 1.5 g / cm3, more preferably 0.7 to 1.3 g / cm3(determined by DIN 51705:2001-06).

[0353] 5 52. Process according to any one of embodiments 1 to 51 wherein carbon content in the granular pyrolytic carbon GPC is in the range of 98 to 100 wt.-%, more preferably 99.5 to 100 wt.-%, even more 99.75 to 100 wt.-%, even more 99.9 to 100 wt.-%.

[0354] 53. Process according to any one of embodiments 1 to 52 wherein the ash content of the granular pyrolytic carbon 10 GPC is in the range of 0.001 to 1 wt.-%, preferably 0.01 to 0.2 wt.-%.

[0355] 54. Process according to any one of embodiments 1 to 53 wherein the second pyrolysis reactor PR2 is heated electrically.

[0356] 15 55. Process according to any one of embodiments 1 to 54 wherein the second pyrolysis reactor PR2 is heated electrically by resistive heating (Joule heating) of the bed material.

[0357] 56. Chemical plant for manufacture of hydrogen from waste, the chemical plant comprising:

[0358] a) a first pyrolysis reactor PR1,

[0359] 20 b) a gas separation unit SU, said gas separation unit SU downstream of and fluidically connected to the first pyrolysis reactor PR1,

[0360] c) a second pyrolysis reactor PR2, said second pyrolysis reactor PR2 downstream of and directly fluidi- cally connected to the gas separation unit SU,

[0361] wherein said second pyrolysis reactor PR2 selected from the group consisting of moving bed reactor, 25 fluidized bed reactor and fixed bed reactor.

[0362] 57. Chemical plant according to embodiment 56 wherein the first pyrolysis reactor PR1 is selected from the group comprising or preferably consisting of fluidized bed reactors, moving bed reactors, entrained flow reactors, stirred tank reactors, rotary kiln reactor and reactors comprising a reactor chamber and a rotation mechanism.

[0363] 30

[0364] 58. Chemical plant according to embodiment 56 or 57 wherein the gas separation unit SU is selected from the group comprising or preferably consisting of flash drums, strippers, distillation columns, quench columns, heat exchangers with cooled surfaces to condense, and combinations thereof.

[0365] 35 59. Chemical plant according to any one of embodiments 56 to 58 wherein the second pyrolysis reactor PR2 is selected from the group consisting of moving bed reactor, fluidized bed reactor and fixed bed reactor and wherein said at least one second pyrolysis reactor PR2 is not a plasma reactor. 240462WO01

[0366] 28

[0367] 60. Chemical plant according to any one of embodiments 56 to 59 wherein the at least one second pyrolysis reac- tor PR2 is a moving bed reactor.

[0368] 5 61. Chemical plant according to any one of embodiments 56 to 60 wherein the at least one second pyrolysis reac- tor PR2 is a moving bed reactor and not a plasma reactor.

[0369] 62. Chemical plant according to any one of embodiments 56 to 61 wherein the chemical plant further comprises a means M for removing at least one member of the group comprising or consisting of NH3, H2S, HCl, HBr from 10 the gas stream GS separated in the gas separation unit SU, said means M downstream of the gas separation unit SU and directly or indirectly fluidically connected to the gas separation unit SU, and upstream of the sec- ond pyrolysis reactor PR2 and directly or indirectly fluidically connected to the second pyrolysis reactor PR2.

[0370] 63. Use of a gas stream GS manufacture by the steps

[0371] 15 a) providing a feedstock F, said feedstock F comprising waste,

[0372] b) converting said feedstock F by a first pyrolysis reaction in a first pyrolysis reactor PR1 to a reaction product RP1, said reaction product RP1 comprising a gas stream GS, and

[0373] c) separating said gas stream GS from said reaction product RP1 in a gas separation unit SU, as a (co-)feedstock for a second pyrolysis reaction in a second pyrolysis reactor PR2, whereby said gas 20 stream GS is converted into hydrogen and granular pyrolytic carbon.

[0374] The invention will be further explained by the following non-limiting examples.

[0375] Examples

[0376] 25 A feedstock F, said feedstock F consisting of mixed plastic waste was provided and converted by a first pyrolysis re- action in a first pyrolysis reactor PR1 to a reaction product RP1, said reaction product RP1 comprising a gas stream GS. Said gas stream GS was separated from said reaction product RP1 in a gas separation unit SU. Said gas stream GS comprised 26 Vol.-% C1−C4 alkanes (“GS1”), and 13 Vol.-% H2.1 Vol.-% N2(“GS2”) or 1 Vol.% O2(“GS3”) was added to the gas stream composition “GS1” in selected examples. Next, said gas stream GSn (n = 30 1,2,3) was converted by a second pyrolysis reaction in a second pyrolysis reactor PR2 into hydrogen H and carbon.

[0377] The second pyrolysis reaction was conducted in a moving bed reactor (examples 1 to 7, invention) or in a plasma reactor according to CN116426308A (comparative examples 1 to 7, prior art).

[0378] The hydrogen yield was calculated for the process according to the present invention by chemical kinetics simula-35 tions using the open-source software Cantera (© Copyright 2023, Cantera Developers) and the chemical reaction mechanism CRECK (Version 2003, © 2023 CRECK Modeling, Politecnico di Milano). As comparison, the hydrogen yield of a plasma process disclosed in CN116426308A was calculated by the same method (comparative examples 1 240462WO01

[0379] 29

[0380] to 7). Furthermore, the yield of the (undesired) soot-precursors ethine and di-ethine in the product gas stream were also calculated using the same method.

[0381] The set up for the calculations was as follows:

[0382] 5 • To compare different reactor concepts (process of present invention vs. process disclosed in CN116426308A, the reaction conditions (temperature T and pressure p), and the residence time (t) were chosen accordingly.

[0383] • Species concentrations change over time, while temperature T and pressure p were kept constant.

[0384] • Changes in residence time (t) were accounted for by adjusting the available reaction time.

[0385] • Due to the lower volumetric extent of the plasma, the residence time is shorter compared to the moving bed 10 • Results were analyzed based on the species concentrations at the end of each simulation in the respective product gas stream.

[0386] The results for examples 1 to 7 and comparative examples 1 to 7 are summarized in Table 1.

[0387] 15

[0388] Table 1: results for examples 1 to 7 and comparative examples 1 to 7.

[0389] Gas stream Temperature Pressure p Residence Molar fraction Molar fraction GS T [°C] [bar] time t [s] H2formed in soot-precur- step e) sors formed [mol-%] in step e)

[0390] [mol-%] Ex.1 GS1 1300 5 6 0.76 0.012 Ex.2 GS1 1300 1 6 0.83 0,025 Ex.3 GS1 1300 4 6 0.77 0.013 Ex.4 GS1 1300 7 6 0.73 0.01 Ex.5 GS1 1300 10 6 0.7 0.009 Comp. GS1 3000 1 1 0.42 0.27 Comp. GS1 3000 5 1 n.a. n.a.

[0391] Comp. GS1 3000 4 1 0.51 0.3 Comp. GS1 3000 7 1 0.53 0.31 Comp. GS1 3000 10 1 0.54 0.32 Ex.6 GS2 1300 5 6 0.76 0.012 Comp. GS2 3000 1 1 0.42 0.2691Ex.7 GS3 1300 5 6 0.75 0.012 Comp.

[0392]

[0393] GS3 3000 1 1 0.43 0.2681the product gas stream further comprised 0.0043 mol-% HCN which is highly undesired. 240462WO01

[0394] 30

[0395] The hydrogen yield obtained from the process according to the present invention is in all tested reaction conditions and compositions of the gas stream GS higher (Examples 1 to 7) than in the plasma process disclosed in CN116426308A (Comparative Examples 1 to 7). In case of a gas stream GS which comprises nitrogen (comparative example 6), highly undesired HCN is formed in the plasma reactor but not in the process of the present invention.

[0396] 5 Furthermore, a process utilizing gas stream GSn for a plasma process results in a higher molar fraction of soot-pre- cursors formed in step e). Accordingly, undesired fouling caused by deposited soot in the second pyrolysis reactor PR2 is more likely in said plasma process than in the process according to the present invention.

[0397] Furthermore, the desired granular pyrolytic carbon (GPC) is having a carbon content of at least 98 wt.-%, an average 10 particle size of 0.5 to 10 mm (determined by sieving with sieves having defined mesh sizes), a BET surface area of 0.001 to 20 m2 / g, preferably 0.001 to 10 m2 / g, even more preferably 0.05 to 5 m2 / g (measured by Hg porosimetry, DIN66133) and a bulk density of the granular pyrolytic carbon GPC is in the range of 0.5 to 1.5 g / cm3(determined by DIN 51705:2001-06) is formed in examples 1 to 7 whereas undesired “nano-sized” carbon is formed in comparative examples 1 to 7.

[0398] 15

Claims

240462WO0131Claims1. Process for manufacture of hydrogen from waste, the process comprising the stepsa) providing a feedstock F, said feedstock F comprising waste,b) converting said feedstock F by a first pyrolysis reaction in a first pyrolysis reactor PR1 to a reaction 5 product RP1, said reaction product RP1 comprising a gas stream GS,c) separating said gas stream GS from said reaction product RP1 in a gas separation unit SU, d) optionally providing a gaseous co-feedstock COF,e) converting said gas stream GS and the gaseous co-feedstock COF optionally provided in step d) by a second pyrolysis reaction in a second pyrolysis reactor PR2 into hydrogen H and granular pyrolytic 10 carbon GPC, wherein the second pyrolysis reaction is conducted in a moving bed reactor, fluidized bed reactor or fixed bed reactor,wherein the temperature in the second pyrolysis reactor PR2 during step e) ranges from 1000 to 1600 °C, and wherein bed material is purposely added in step e).15 2. Process according to claim 1 wherein the feedstock F is selected from the group consisting of plastic waste, bio waste and mixtures thereof.

3. Process according to claim 1 or 2 wherein the first pyrolysis reaction in the first pyrolysis reactor PR1 in step b) is conducted in an inert atmosphere.

204. Process according to any one of claims 1 to 3 wherein gas stream GS is separated from the reaction product PR in step c) by a method selected from the group comprising or preferably consisting of condensation, ex- traction, adsorption and combinations thereof.25 5. Process according to any one of claims 1 to 4 wherein the gas stream GS comprises C1−C4 alkanes.

6. Process according to any one of claims 1 to 5 wherein at least one gaseous co-feedstock COF is provided in step d) and wherein said gaseous co-feedstock COF is selected from the group comprising or preferably con- sisting of hydrogen, natural gas, synthetic methane, bio-methane, industrial off gas, biogas, sewage gas and 30 mixtures thereof.

7. Process according to any one of claims 1 to 6 wherein at least one gaseous co-feedstock COF is provided in step d) and wherein said gaseous co-feedstock COF contains hydrogen.35 8. Process according to any one of claims 1 to 7 wherein the molar ratio of H2 / C1+of the total feed stream TF for the second pyrolysis, the gas stream GS and at least one co-feedstock COF, is ranging from 0.1 to 25.240462WO01329. Process according to any one of claims 1 to 8 wherein the total feed gas stream TF for the second pyrolysis reactor, the gas stream GS and at least one co-feedstock COF, is adjusted by the co-feedstock COF to a fixed molar ratio of H2 / C1+, to the operation point.5 10. Process according to any one of claims 1 to 9 wherein gas stream GS has a temperature of 0 to 100 °C when fed into the second pyrolysis reactor PR2 in step e) and wherein the temperature of hydrogen H and / or of granular pyrolytic carbon when leaving the second pyrolysis reactor PR2 after step e) has a temperature of 10 to 200 °C.10 11. Process according to any one of claims 1 to 10 wherein gas stream GS has a temperature within a margin of + / - 20°C, after separation from said reaction product RP1 in step c) and when fed into the second pyrolysis reactor PR2 in step e).

12. Process according to any one of claims 1 to 11 wherein said purposely added bed material has an average 15 particle size of 1 to 10 mm, preferably 3 to 8 mm (determined by sieving with sieves having defined mesh sizes).

13. Process according to any one of claims 1 to 12 wherein said purposedly added bed material is solid carbon and wherein said solid carbon is essentially free of metal(s).2014. Process according to any one of claims 1 to 13 wherein the residence time of gas stream GS in the second pyrolysis reactor PR2 during step e) ranges from 0.5 to 1500 s.

15. Process according to any one of claims 1 to 14 wherein the conversion rate of the second pyrolysis reaction 25 ranges from 25 to 90 %, preferably from 30 to 85 %, more preferably from 40 to 80 %, most preferably from 50 to 80 % (based on the total feed stream TF).

16. Chemical plant for manufacture of hydrogen from waste, the chemical plant comprising:a) a first pyrolysis reactor PR1,30 b) a gas separation unit SU, said gas separation unit SU downstream of and fluidically connected to the first pyrolysis reactor PR1,c) a second pyrolysis reactor PR2, said second pyrolysis reactor PR2 downstream of and directly or indi- rectly fluidically connected to the gas separation unit SU,wherein said second pyrolysis reactor PR2 selected from the group consisting of moving bed reactor, 35 fluidized bed reactor and fixed bed reactor.240462WO013317. Chemical plant according to claim 16 wherein the second pyrolysis reactor PR2 is selected from the group consisting of moving bed reactor, fluidized bed reactor and fixed bed reactor and wherein said at least one second pyrolysis reactor PR2 is not a plasma reactor.5

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