FI20245304A1

FI20245304A1 - Process, equipment and catalyst for producing carbon

Info

Publication number: FI20245304A1
Application number: FI20245304A
Authority: FI
Inventors: Prem Kumar Seelam; Riikka Kupila; Noora Alapiha; Hannu Snellman; Ilkka Tanttinen; Samuli Räsänen; Ville Martikainen
Original assignee: Hycamite Tcd Tech Oy
Priority date: 2024-03-14
Filing date: 2024-03-14
Publication date: 2025-09-15
Also published as: WO2025191217A1

Abstract

The application relates to a method and an apparatus for producing at least carbon by a chemical reaction with a catalyst in a reactor. A reactant is supplied to the reactor comprising at least one catalyst surface for the chemical reaction and at least one space in the reactor, and the catalyst surface contains a metal catalyst. The chemical reaction is performed in the reactor in which the reactant is arranged into contact with the catalyst surface to form the carbon comprising an allotrope of carbon, and nano-scale metal particles are detached from the catalyst surface by the formed carbon. The chemical reaction is continued in the space of the reactor and an amount of the carbon is grown by the formed carbon which comprises the detached nano-scale metal particles to form a carbon component. Further, the application relates to a catalyst for the chemical reaction.

Description

METHOD, APPARATUS AND CATALYST FOR PRODUCING CARBON

FIELD

The application relates to a method defined in claim 1, an apparatus defined in claim 10 and a catalyst defined in claim 14 for producing at least carbon by a chemical reaction with a catalyst in a reactor.

BACKGROUND

It is known different methods, devices and cat- alysts for producing hydrogen from hydrocarbons, such as methane. Further, it is known to produce a solid carbon. Metal catalysts, such as metal alloy catalysts, may be used for producing hydrogen, e.g. in a pyrolysis, and the metal alloys typically are used at high temper- atures.

OBJECTIVE

An objective is to alleviate the disadvantages mentioned above. In particular, the objective is to dis- close a novel type of method for forming carbon. Fur- ther, the objective is to disclose an improved process for methane decomposition. Further, the objective is to achieve an effective process for forming solid products and/or hydrogen. Further, the objective is to provide an effective process to low temperatures.

N e SUMMARY

O The method, apparatus and catalyst are charac- = 30 terized by what are presented in the claims.

TY The method for producing at least carbon by a

E chemical reaction with a catalyst in a reactor comprises 3 supplying a reactant to the reactor, performing the 2 chemical reaction in the reactor in which the reactant

N 35 is arranged into contact with a catalyst surface to form

N the carbon, and detaching small metal particles from the catalyst surface, and continuing the chemical reaction in the reactor and growing an amount of the carbon by the formed carbon and the detached small metal particles to form a carbon component.

The apparatus for producing at least carbon by a chemical reaction with a catalyst in a reactor com- prises at least one reactor for performing the chemical reaction, at least one catalyst surface inside the re- actor for the chemical reaction, wherein a reactant is arranged into contact with the catalyst surface to form the carbon in the reactor and to detach small metal particles from the catalyst surface, and the chemical reaction is arranged to continue in the reactor for growing an amount of the carbon by the formed carbon and the detached small metal particles to form a carbon component.

The catalyst comprises at least one catalyst surface, which contains a metal catalyst for the chem- ical reaction to form the carbon.

DETAILED DESCRIPTION

The method for producing at least carbon by a chemical reaction with a catalyst in a reactor comprises supplying a reactant to the reactor comprising at least one catalyst surface inside the reactor for the chemical reaction and at least one space in the reactor, which < the carbon can occupy or where the carbon can be col-

S lected, and the catalyst surface contains a metal cat-

O alyst. The chemical reaction is performed in the reactor = 30 in which the reactant is arranged into contact with the = catalyst surface to form the carbon comprising an allo-

E trope of carbon, e.g. carbon nanofibers, carbon nano- 3 tubes, single wall carbon nanotubes, multiwalled carbon

O nanotubes, carbon nano onions, carbon nano shells, car-

N 35 bon micro shells, amorphous carbon, graphene, graphite

N fibers and/or graphite, and small metal particles,

preferably at least nano-scale metal particles, are de- tached from the catalyst surface by the formed carbon.

Then a composite of the allotrope of carbon comprising the nano-scale metal particles may be formed. The chem- ical reaction is continued in the space of the reactor and an amount of the carbon is grown by the formed carbon which comprises the detached nano-scale metal particles, i.e. by the composite, to form a carbon component. Pref- erably, the carbon component is recovered, e.g. by tak- ing the carbon component out or discharging the carbon component from the reactor or by moving the carbon com- ponent to a next reactor, a next space of the reactor or an intermediate vessel. A carbon product may be formed from the carbon component.

An apparatus for producing at least carbon by a chemical reaction with a catalyst in a reactor com- prises at least one reactor for performing the chemical reaction, at least one catalyst surface inside the re- actor for the chemical reaction and at least one space in the reactor for collecting the carbon, and the cat- alyst surface contains a metal catalyst, wherein a re- actant is arranged into contact with the catalyst sur- face to form the carbon comprising an allotrope of car- bon, e.g. carbon nanofibers, carbon nanotubes, single wall carbon nanotubes, multiwalled carbon nanotubes, carbon nano onions, carbon nano shells, carbon micro < shells, amorphous carbon, graphene, graphite fibers

S and/or graphite, in the reactor and to detach at least 0 nano-scale metal particles from the catalyst surface by = 30 the formed carbon, and the chemical reaction is arranged to continue in the space of the reactor for growing an : amount of the carbon by the formed carbon which com- 3 prises the detached nano-scale metal particles to form

O a carbon component. Further, the apparatus may comprise

N 35 at least one recovering means for recovering the carbon

N component, e.g. by taking the carbon component out or discharging the carbon component from the reactor or by moving the carbon component to a next reactor, a next space of the reactor or an intermediate vessel.

In this context, the catalyst surface means any catalyst surface, which is formed of catalyst material, and which comprises a metal catalyst. Preferably, the catalyst material contains at least a metal catalyst, e.g. metal alloy catalyst. In one embodiment, the cat- alyst surface is selected such that small metal parti- cles, e.g. nano-scale particles, may be detached from the catalyst surface when carbon is formed. The catalyst surface may be any surface, e.g. a surface of a wall of the reactor, a surface of a reactor element, or a surface of the catalyst, such as a surface of a catalyst element or catalyst structure, or suitable surface. In one em- bodiment, the space of the reactor comprises at least one catalyst surface, or catalyst surface of the cata- lyst structure or catalyst element. In one embodiment, the space is formed from the catalyst, in one embodiment from the catalyst structure or catalyst element. In this context, the catalyst means any catalyst which comprises at least one catalyst surface. Preferably the catalyst is formed of the catalyst material. The catalyst may have any size and shape. In one embodiment, the catalyst comprises the catalyst element or catalyst structure.

In one embodiment, the catalyst is the catalyst element < or catalyst structure. In one embodiment, the catalyst

S consists of the catalyst material. In one embodiment, 0 the catalyst is in the form of a fixed structure. In embodiment, the catalyst has the fixed structure which = is formed of the catalyst material comprising at least

E: one catalytic agent. Preferably, the catalyst material 3 comprises at least one catalytic agent. The catalyst

O material may be formed of one or more components. The

O 35 catalyst material may contain catalytically active met- als, carbon, other catalytically active agent or any combination thereof, as the catalytic agent. In one em- bodiment, the catalyst material is formed of one or more catalytic agent. In one embodiment, the at least one catalyst surface for the chemical reaction comprises one 5 or more catalytic agent. In one embodiment, the at least one catalyst surface for the chemical reaction comprises at least two catalytic agents. In one embodiment, the at least one catalyst surface for the chemical reaction is made of one or more catalytically active metals and/or carbon. In one embodiment, the catalyst or at least its surface comprises one or more catalytically active metals and carbon. In one embodiment, the at least one surface of the catalyst, e.g. catalyst layer, is formed of a composition of the catalyst material which differs from the other catalyst material, and the said surface is arranged onto the other catalyst mate- rial. In one embodiment, the surface of the catalyst comprises at least one different catalytic agent than the other catalyst material in the catalyst. In one embodiment, the catalyst comprises a surface layer, e.g. an outer active layer, on the catalyst, e.g. on the surfaces of the fixed structure, preferably as coating on other catalyst material. In one embodiment, the whole catalyst is formed of the same catalyst material. In one embodiment, the catalyst is porous, or the surface, e.g. the surface layer, is porous. In one embodiment, the + catalyst, or the catalyst surface, is non-porous. In one

S embodiment, the catalyst has a surface area of at least & 0.2 - 30 m?/g, in one embodiment 5 - 25 m?/g. + 30 In one embodiment, the catalyst material and/or = the at least one catalyst surface for the chemical re- = action is made of one or more catalytically active met- 3 als selected from the group consisting of nickel, cop-

O per, iron, aluminium, titanium, cobalt, manganese, chro-

N 35 mium, silicon, carbon, or an oxide thereof, or any com-

N bination thereof. In one embodiment, the at least one catalyst surface for the chemical reaction is made of two catalytically active metals, wherein the two cata- lytically active metals are selected from the group con- sisting of nickel, copper, iron, aluminium, titanium, cobalt, manganese, chromium, silicon, carbon, and any combination thereof. In one embodiment, the catalyst material and/or the at least one catalyst surface is made of nickel, copper, iron, and/or cobalt. In one embodiment, the catalyst material and/or the at least one catalyst surface for the chemical reaction is made of a metal alloy. In one embodiment, the metal alloy is

Ni-Cu metal alloy.

In one embodiment, the method further comprises pre-treating the catalyst surface for modifying the sur- face of the catalyst and/or for improving the activity of the catalyst. In one embodiment, the catalyst surface is pre-treated before the use or in the beginning of the chemical reaction. In one embodiment, the catalyst sur- face is pre-treated before the chemical reaction or be- fore attaching the catalyst to the reactor. In one em- bodiment, the catalyst surface is pre-treated in the beginning of the chemical reaction. The catalyst surface can be pre-treated in a desired way. In one embodiment, the catalyst surface is pre-treated by an acid, alkali, heat, electrochemical treatment, or their combination.

In one embodiment, the catalyst surface is pre-treated < by an acid, heat or their combination. In one embodiment,

S the method comprises pre-treating the catalyst surface

O for modifying the surface of the catalyst and/or for = 30 improving the activity of the catalyst, and the catalyst = surface is pre-treated at least by an acid, heat or

E their combination. In one embodiment, the catalyst sur- 3 face is treated by heat. In one embodiment, the catalyst

O surface is activated at temperature of 750 — 900 °C, in

N 35 one embodiment at temperature of 800 — 850 °C. In one

N embodiment, the catalyst surface is activated at temperature of 800 - 850 °C in the beginning of the chemical reaction, and after that temperature is de- creased, e.g. to temperature of 600 —- 650 °C in which the reaction is continued. In one embodiment, the chem- ical reaction at higher temperature is only fractional part of total operational time of the catalyst. In one embodiment, the catalyst surface is pre-treated by at least acid-treating using an acid-treatment. In one em- bodiment, HNO3 or other suitable acid is used as the acid. In one embodiment, the catalyst material is di- gested and etched during the acid pre-treatment. In one embodiment, temperature which is between a room temper- ature and 120 °C is used for the acid digestation. In one embodiment, 0.1 M to 5 M HNO; diluted solution is used in the acid-treatment. In one embodiment, the acid digestion is performed using HNO; diluted with 1 molar solution at temperature of about 90 °C. Further, in one embodiment rate of flow of medium agent, e.g. gas, through the catalyst material per time unit affects an activation of the catalyst surface. The metal alloy sur- face may be, at least partially, oxidized. In one em- bodiment, the catalyst material may be further calcined and reduced. In one embodiment, the metal alloy surface is activated at low temperature via oxidation and re- duction of the alloy catalyst. In one embodiment, the method further comprises: acid-treating the catalyst < surface using an acid, and digesting and etching the

S metal catalyst during the acid treatment. In one embod- 0 iment, the catalyst surface is modified such that sur- = 30 face irregularities, e.g. pores, protrusions from the = surface, microstructures, spikes, or other irregulari- = ties, are arranged onto the catalyst surface. By means 3 of the pre-treatment, a surface area of the catalyst

O surface, and simultaneously a catalytic activity, can

N 35 be increased, and thus vield of the products can be

N improved. When the catalyst surface is pre-treated, the performance of the catalyst can be improved at low tem- peratures in the process. In one embodiment, higher tem- perature in the beginning of the chemical reaction pro- vides loosening of small metal particles by means of the generated carbon from the catalyst surface to provide primary metal particles to a composite of the carbon allotrope and small metal particles. In one embodiment, the acid treatment forms small metal particles, e.g. nano-scale metal particles, onto the surface of the cat- alyst, and the said metal particles may be detached from the catalyst surface by the generated carbon.

The predetermined chemical reaction is per- formed by the catalyst in the reactor, preferably in the space inside the reactor. In one embodiment, the chemical reaction is performed at a pressure between 0 - 5 bars and/or at a temperature between 600 - 900 °C. In one embodiment, the chemical reaction is performed at a re- action temperature of between 600 — 900 °C. In one em- bodiment, the chemical reaction is performed under the atmospheric pressure. In one embodiment, the chemical reaction is performed under the pressure of between 0 - 5 bars. In one embodiment, the contact time of the re- actant with the catalyst is selected based on the reac- tant and the catalyst. In one embodiment, the chemical reaction is a hydrocarbon decomposition or methane de- composition. In one embodiment, the chemical reaction < is a chemical reaction selected from the group consist-

S ing of a methane splitting, catalysed methane splitting, 0 catalysed pyrolysis, catalysed hydrocarbon pyrolysis, = 30 catalysed methane pyrolysis, catalytic hydrocarbon de- = composition, catalytic methane decomposition, thermo- = catalytic methane decomposition, chemical vapor deposi- 3 tion, other reaction, or any combination thereof. In one

O embodiment, the chemical reaction is the reaction, in

O 35 which the hydrocarbon is selected from the group of C:-

i1o-alkanes, such as methane and ethane, C,.ipo—alkenes and

Co-10-alkynes.

The apparatus may comprise one or more reac- tors. The reactor may be any reactor comprising at least the space for the chemical reaction. In one embodiment, the reactor is selected from the group consisting of a pyrolysis reactor, fluidized reactor, fixed reactor, fixed bed reactor, rotary kiln reactor or any combination thereof. In one embodiment, the apparatus comprises the reactor comprising at least one catalyst element or cat- alyst structure, reactor comprising at least one catalyst wall, vertical reactor, tube reactor, pyrolysis reactor, fluidized reactor, rotary kiln reactor or any combination thereof as the reactor. The reactors which are arranged into series, or in parallel, may be similar or different reactors. In one embodiment, the reactor comprises a reactor chamber, e.g. at least one reactor chamber. In one embodiment, the reactor comprises at least two or more reactor chambers. In one embodiment, two or more reaction chambers are similar, or alternatively they are different reaction chambers. In one embodiment, the space of the reactor is the reactor chamber. It is im- portant that the formed carbon can be accommondated to the space.

In this context, the reactant means any suit- able reactant, which can be treated in the process. In < one embodiment, the reactant is a hydrocarbon selected

S from the group of Cijo-alkanes, such as methane and

Oo ethane, Co o-alkenes, and C> jo-alkynes. In one embodi- = 30 ment, the reactant comprises at least methane.

In one embodiment, the reactant is arranged to

E: flow from top to bottom in the reactor. The reactant 3 flow direction from top to bottom enables easier carbon

O recovery from the bottom.

S

In one embodiment, hydrogen is formed by the chemical reaction and recovered. In one embodiment, the hydrogen is discharged from the reactor.

In one method embodiment, a catalyst is formed from the catalyst material, wherein the catalyst com- prises at least one surface for the chemical reaction, and the catalyst surface is pre-treated to modify the surface of the catalyst and/or to improve the activity of the catalyst, and the catalyst is arranged to the reactor, a reactant is fed to the reactor and the chem- ical reaction is performed in the reactor, and at least solid carbon is formed, and it may be recovered. Pref- erably, the reactant is arranged to contact with the catalyst surface in the reactor. In one embodiment, the steps comprising the feeding of the reactant and the performance of the chemical reaction, and also the re- covery of the carbon, can be repeated one or more times, when the same catalyst is used in the reactor.

In one embodiment, the method comprises: 1) providing a catalyst; ii) letting the reactant to con- tact a surface of the catalyst at a predefined reaction temperature, wherein the predefined reaction tempera- ture is selected based on the catalyst and the reactant, thereby forming at least carbon in solid form; and iii) recovering the formed carbon. In one embodiment, hydro- gen is formed in ii), and the formed hydrogen is col- < lected. In one embodiment, in ii), the predefined reac-

S tion temperature is between 600 — 900 °C. In one embod- 0 iment, in ii), the pressure is between 0 - 5 bars. In = 30 one embodiment, the steps ii) and iii) are repeated more times.

E The carbon comprises an allotrope of carbon,

S e.g. carbon nanotube, carbon nanofiber, single wall car- 3 bon nanotubes, multiwalled carbon nanotubes, carbon nano

N 35 onions, carbon nano shells, carbon micro shells, amor-

N phous carbon, graphene, graphite fibers and/or graphite.

In one embodiment, the allotrope of carbon comprises at least carbon nanofibers, carbon nanotubes and/or graph- ite. In one embodiment, the carbon is formed as a reac- tion product in the solid form. In one embodiment, the reaction products in solid form consists essentially of carbon. In one embodiment, the carbon and hydrogen are produced. In one embodiment, the one or more reaction products in solid form consists of the allotrope of carbon, preferably consists essentially of carbon nano- tube and carbon nanofiber.

In one embodiment, the carbon allotrope, such as carbon nanotubes, carbon nanofibers, single wall car- bon nanotubes, multiwalled carbon nanotubes, carbon nano onions, carbon nano shells, carbon micro shells, amor- phous carbon, graphene, graphite fibers and/or graphite, releases small metal particles, preferably nano-scale metal particles, from the catalyst surface during the process. Preferably, the small metal particles, espe- cially nano-scale metal particles, come loose from the catalytically active catalyst surface. Then, the re- leased small metal particles together with the carbon allotrope catalyses the chemical reaction. Preferably, the released small metal particles are used as seed for a composite, such as an additional catalyst composite, comprising the metal particles and the carbon allotrope, and this composite can be formed in situ. By means of < the composite the efficiency of the process can be im-

S proved. 0 In one embodiment, the carbon comprising the = 30 allotrope of carbon is separated, e.g. dropped down, = from the catalyst surface in the reactor and the chem- = ical reaction is continued using the detached nano-scale 3 metal particles attached to the formed carbon and using

O the catalyst surface. Preferably, the chemical reaction

N 35 continues onto the catalyst surface and by means of the

N composite of the carbon and nano-scale particles in the space of the reactor, i.e. two chemical reactions con- tinue simultaneously. The allotrope of carbon, formed on the catalyst surface, may fall down from the catalyst surface and/or the allotrope of carbon may be dropped, e.g. by suitable means.

In one embodiment, the apparatus comprises one or more reactors, e.g. sequentially in series or in parallel. In one embodiment, the reactor comprises more than one reactor spaces, such as reactor chambers, e.g. sequentially or in parallel. The reactor may comprise two reactor spaces, three reactor spaces and/or more than three reactor spaces. In one embodiment, the reac- tor comprises at least a first reactor space and second reactor space, and the carbon comprising the allotrope of carbon is formed in the first reactor space, and the formed carbon is moved from the first reactor space to the second reactor space in which the amount the carbon is grown. In one embodiment, the carbon comprising the allotrope of carbon is formed in the defined reactor space, and the formed carbon is moved from the said reactor space to the next reactor space in which the amount of the carbon is increased.

The catalyst comprises at least one catalyst surface, which contains a metal catalyst, e.g. metal alloy for the chemical reaction to form the carbon com- prising an allotrope of carbon. The catalyst surface may < comprise metal particles. At least nano-scale metal par-

S ticles are arranged to detach from the catalyst surface 0 by the carbon, preferably by the allotrope of carbon, = 30 e.g. carbon nanofibers, carbon nanotubes, single wall = carbon nanotubes, multiwalled carbon nanotubes, carbon

E nano onions, carbon nano shells, carbon micro shells, 3 amorphous carbon, graphene, graphite fibers and/or

O graphite, and a structure of the catalyst is two-dimen-

O 35 sional or three-dimensional.

In one embodiment, the catalyst with the fixed structure, i.e. a fixed-structure catalyst, has a two- dimensional structure with predetermined dimensions, e.g. length and width, and with predetermined shape.

In one embodiment, the catalyst with the fixed structure, i.e. a fixed-structure catalyst, has a three- dimensional structure with predetermined dimensions, e.g. length, width, depth and/or diameter, and with pre- determined shape. In one embodiment, the appearance structure of the catalyst is tubular.

The catalyst comprises a predetermined struc- ture. Further, the catalyst may have a predetermined cross-section. In one embodiment, the catalyst has a predetermined pattern of the cross-section, e.g. honey- comb pattern or lattice pattern. In one embodiment, the catalyst comprises a honeycomb structure, lattice struc- ture, mesh structure, netting, grid structure, knitted structure, spiral structure, screw structure, tube structure, rod structure, plate structure, other struc- ture through which gas can flow, or other suitable structure. In one embodiment, the catalyst is a mono- lith. In one embodiment, the catalyst comprises one or more catalyst elements. In one embodiment, the catalyst is formed of one or more catalyst elements. The catalyst elements may be selected from any elements, e.g. rods, plates, mesh, or other suitable element. In one embod- < iment, the catalyst is formed of metal wire, metal mesh,

S metal structure, metal fabric or the like. In one em-

Oo bodiment, the catalyst is formed of a flexible metal = 30 material, e.g. metal fabric. Preferably the catalyst = surface is arranged at least onto a surface of the cat- z alyst, catalyst element and/or catalyst structure. 3 In one embodiment, the metal catalyst comprises

O one or more catalytically active metals selected from

N 35 the group consisting of nickel, copper, iron, aluminium,

N titanium, cobalt, manganese, chromium, silicon, carbon or an oxide thereof, or any combination thereof. In one embodiment, the catalyst is a metal alloy catalyst com- prising at least two catalytically active metals se- lected from the group consisting of nickel, copper, iron, aluminium, titanium, cobalt, manganese, chromium, silicon, carbon or an oxide thereof, or any combination thereof.

In one embodiment, the catalyst is formed from the catalyst material, such as from powder of the cat- alyst material. In one embodiment, the catalyst is formed from powder of the catalyst material to form a two-dimensional catalyst or three-dimensional catalyst.

In one embodiment, the catalyst is formed from a metal alloy, preferably powder of the metal alloy. In one embodiment, the catalyst is formed from a predetermined material to form a two-dimensional or three-dimensional shape and the material is coated catalytically active material containing metal catalyst, such as metal alloy.

In one embodiment, the catalyst can be formed by typical metal production methods, where metal powder is used.

In one embodiment, the catalyst is formed by printing, coating, depositing, extruding, rolling, cutting, laser cutting or any combination thereof. In one embodiment, the catalyst is formed by printing, coating, depositing, extruding, or by another suitable method. In one embod- iment, the coating of the catalyst is carried out by < heat spraying, porous plating, metal plating, blast pro-

S cessing, other suitable coating, or any combination 0 thereof. In one embodiment, the catalyst is formed by = 30 printing, 3D-printing, direct metal laser sintering = (DMLS), selective laser sintering (SLS), laser-based : powder bed fusion technology (L-PFB), stereolithogra- 3 phy, and/or extrusion printing, or any combination

O thereof. In one embodiment, the catalyst is formed by

N 35 printing. In one embodiment, the catalyst is formed from

N the catalyst material using the 3D-printing. In one embodiment, the 3D-printing is selected from the group consisting of binder jetting, directed energy deposi- tion, material extrusion, powder bed fusion, sheet lam- ination, vat polymerisation, laser-based powder bed fu- sion technology (L-PFB), and wire arc additive manufac- turing, or any combination thereof. The desired struc- ture and/or shape of the catalyst is provided during the manufacture of the catalyst, e.g. during the printing.

In one embodiment, the geometry of the catalyst, e.g. three-dimensional catalyst, can be optimized for cata- lytic activity such that solid products will not block the catalyst and will not be trapped in the catalyst, e.g. in the catalyst structure.

The catalyst can be arranged to an apparatus, e.g. reactor, and preferably inside the reactor.

In one embodiment, the catalyst comprises an attachment means for attaching the catalyst, e.g. to the apparatus. The catalyst can be attached by means of the attachment means to the apparatus, e.g. reactor. Any attachment means can be used to attach the catalyst to the apparatus. In one embodiment, the catalyst comprises the attachment means for attaching the catalyst to the apparatus, and the attachments means is an integrated part of the catalyst. In one embodiment, the catalyst is attached to the reactor walls by the attachment means.

In one embodiment, the attachment is selected from the < group consisting of hooks, connectors, other connecting

S element, or any combination thereof. Preferably, the cat- 0 alyst can be easily replaced in the apparatus or removed = 30 from the apparatus, e.g. for regeneration purposes.

In one embodiment, the catalyst comprises a re-

E: action space in which the chemical reaction is performed, 3 and the catalyst surface is arranged inside the reaction

O space. In one embodiment, the catalyst comprises a re-

N 35 actor chamber as the reaction space. In one embodiment,

N the catalyst forms a reactor chamber.

In one embodiment, the nano-scale metal parti- cles are attached to the formed carbon comprising the allotrope of carbon, such as comprising the carbon nan- ofibers, carbon nanotubes, single wall carbon nanotubes, multiwalled carbon nanotubes, carbon nano onions, carbon nano shells, carbon micro shells, amorphous carbon, gra- phene, graphite fibers and/or graphite, to form an ad- ditional catalyst composite for continuating the chemical reaction. In one embodiment, the nano-scale metal parti- cles are attached to the formed carbon comprising the allotrope of carbon, such as comprising at least or mainly the carbon nanofibers and/or carbon nanotubes, to form an additional catalyst composite for continuating the chemical reaction. Preferably, the additional cata- lyst composite comprises the formed carbon, e.g. the car- bon nanofibers, carbon nanotubes, single wall carbon nanotubes, multiwalled carbon nanotubes, carbon nano onions, carbon nano shells, carbon micro shells, amor- phous carbon, graphene, graphite fibers and/or graphite, in one embodiment the carbon nanofibers and/or carbon nanotubes, and further the nano-scale metal particles.

In one embodiment, the catalyst is a detachable catalyst, i.e. the catalyst can be easily detached from the apparatus, e.g. from the reactor.

In one embodiment, the catalyst can be treated, e.g. by heating, regenerating and/or cleaning. In one < embodiment, the catalyst is detached from the apparatus,

S such as from the reactor, before treating. In one embod- 0 iment, the catalyst is treated in the apparatus. = 30 In one embodiment of the preparation of the = catalyst, the method comprises: providing one or more = catalyst components, e.g. catalyst agents, to form the 3 catalyst material; and forming the catalyst from the

O catalyst material. In one embodiment of the preparation

O 35 of the catalyst, the method comprises: providing one or more catalyst components, e.g. catalyst agents, to form the catalyst material; depositing the catalyst material and forming the catalyst from the catalyst material. The depositing may be repeated one or more times. In one embodiment, the catalyst is pre-treated before the chem- ical reaction, e.g. as presented above.

In one embodiment, the depositing is additive manufacturing such as 3D-printing, direct metal laser sintering (DMLS), selective laser sintering (SLS), la- ser-based powder bed fusion technology (L-PFB), stere- olithography, and/or extrusion printing, or any combi- nation thereof. In one embodiment, the 3D-printing is selected from the group consisting of binder jetting, directed energy deposition, material extrusion, powder bed fusion, sheet lamination, vat polymerisation, and wire arc additive manufacturing, or any combination thereof.

The catalyst can be used in a desired apparatus and/or in a desired method or process. In one embodiment, the catalyst is used in a hydrocarbon decomposition or methane decomposition. In one embodiment, the catalyst is used in the chemical reaction selected from the group consisting of a methane splitting, catalysed methane splitting, catalysed pyrolysis, catalysed hydrocarbon pyrolysis, catalysed methane pyrolysis, catalytic hy- drocarbon decomposition, catalytic methane decomposi- tion, thermocatalytic methane decomposition, chemical < vapor deposition, other reaction, or any combination

S thereof. In one embodiment, the catalyst is used in a 0 reactor, vertical reactor, tube reactor, fixed bed re- = 30 actor, fixed reactor, pyrolysis reactor, fluidized reac- = tor, rotary kiln reactor or any combination thereof. = In one embodiment, the method or apparatus is 3 used in a hydrocarbon decomposition or methane decompo-

O sition. In one embodiment, the method or apparatus is

N 35 used in a methane splitting, catalysed methane split-

N ting, catalysed pyrolysis, catalysed hydrocarbon pyrolysis, catalysed methane pyrolysis, catalytic hy- drocarbon decomposition, catalytic methane decomposi- tion, thermocatalytic methane decomposition, chemical vapor deposition, other reaction, or any combination thereof. In one embodiment, the method is used in a reactor, vertical reactor, tube reactor, fixed reactor, fixed bed reactor, pyrolysis reactor, fluidized reactor, rotary kiln reactor or any combination thereof.

Thanks to the invention an effective method and process can be provided to produce solid products and hydrogen. The solid product with high purity can be achieved. Further, thanks to the invention, the contin- uos process can be provided easily. Further, the carbon formation can be continued longer in the reactor, and even in multiple reactors or multiple spaces of the reactor. By means of the invention the catalyst with a long lifetime can be provided in the reactor, and the catalyst keeps an activity.

The invention offers a possibility to achieve the carbon product and hydrogen with good properties easily. By means of the invention simpler balance of the process can be achieved. Further, methane pyrolysis or methane decomposition efficiency can be improved. Fur- ther, optimal amount of metal catalyst can be used in the catalyst, and an extra amount of material is not needed to form the catalyst. x

S BRIEF DESCRIPTION OF THE DRAWINGS

0 The accompanying drawings, which are included = 30 to provide a further understanding of the invention and constitute a part of this specification, illustrate some : embodiments of the invention and together with the de- 3 scription help to explain the principle of the inven-

O tion. In the drawings:

N 35 Fig. 1 shows carbon forming in a reactor ac-

N cording to one embodiment, and

Figs. 2 and 3 show SEM figures of carbon ac- cording to another embodiments.

EXAMPLES

The process for producing at least carbon, and further hydrogen, is performed in a reactor. The reactor comprises at least one space in which carbon in a solid form is formed, and which forms at least one reactor chamber. In the chemical reaction, the carbon, and also the hydrogen, are formed by using a catalyst in the reactor. The reactor is a vertical tube reactor with the catalyst.

The catalyst structure comprising a catalyst is arranged inside the space of the reactor, and the catalyst structure comprises at least one surface for the chemical reaction. Alternatively, the catalyst structure forms the space, i.e. reactor chamber, in the reactor. The catalyst is formed of catalyst material such that the catalyst consists of the catalyst mate- rial, such as metal alloy. The catalyst surface is pre- treated by means of an acid and/or heat to modify the surface of the catalyst and/or to improve the activity of the catalyst. The catalyst may be prepared by 3D- printing from the metal alloy powder to form a fixed catalyst having desired structure and dimensions.

A reactant comprising hydrocarbons, such as < methane, is fed to the reactor and the chemical reaction

S is performed in the reactor. The reactant is arranged o to contact with the catalyst surface in the space of the = 30 reactor. The carbon comprising an allotrope of carbon, = such as carbon nanofibers, carbon nanotubes, single wall

E carbon nanotubess, multiwalled carbon nanotubes, carbon 3 nano onions, carbon nano shells, carbon micro shells,

O amorphous carbon, dgraphene, graphite fibers and/or

O 35 graphite, is formed. Nano-scale metal particles are de- tached from the catalyst surface by the formed carbon.

The chemical reaction is continued in the space of the reactor and an amount of the carbon is grown by the formed carbon which comprises the detached nano-scale metal particles to form a carbon component. Fig. 1 shows the carbon forming in the reactor, in which simultane- ously nano-scale metal particles are detached from the catalyst surface by the formed carbon. At least the carbon component is recovered as a solid reaction prod- uct from the reactor. Further hydrogen is formed and recovered.

Example 1

In this example, the reactor as defined above is used in the process. The reactor comprises one space, i.e. reactor chamber, in which the carbon is formed and from which the solid carbon is recovered.

Example 2

In this example, the reactor as defined above is used in the process. The reactor comprises two spaces, i.e. two reactor chambers, which are arranged one after another, such as one on top of the other. The carbon is formed in the first reactor chamber from which the formed carbon comprising metal particles is moved downwards to the second reactor chamber. In the second reactor chamber the chemical reaction is continued by a < composite of the formed carbon and released nano-scale

S metal particles. g + 30 Example 3

In this example, two tests relating to a me-

E: thane decomposition, was carried out in a vertical tube

S reactor comprising two reactor parts which was arranged 3 one on top of the other (high was about 500 mm, and

N 35 diameter was about 135 mm). The reactant, CH, gas, was

N used in the tests.

In the first test, the catalyst material was a metal alloy catalyst, and the tube was formed from the catalyst material. The temperature was 640°C in the first test. The test was carried out at atmospheric pressure. The process time was 49.7 hours in the test (Test A). The catalyst material was acid-treated in an acid-treatment and reduced for 90 min at temperature of 470 °C in a calcination oven before the test. The reac- tant, CH, gas, was fed to the tube reactor. Flow rate of

CH: gas was on average 200-400 ml/min. The test was stopped after 49.7 hours. There was 98.54 g carbon in the tube. Fig. 2 presents a SEM figure of the formed carbon comprising metal alloy catalyst particles.

In the second test, the catalyst was the formed carbon which was formed in the first test and which comprised catalyst particles detached from the catalyst walls during the first test. Density of the carbon- catalyst composite was 0.325 g/cm3. The carbon-catalyst composite was crushed, and about 30 g the composite was packed into the reactor. The carbon-catalyst composite was reduced for 90 min at temperature of 470 °C before the test. The temperature was 640°C in the second test.

The reactant, CH, gas, was fed to the tube reactor. Flow rate of CH, gas was 200 ml/min. The test was carried out at atmospheric pressure. The test drive was stopped af- ter 5.66 hours, and carbon formed 6.88 g during the test < drive. Fig. 3 presents a SEM figure of the formed carbon

S comprising metal alloy catalyst. g + 30 The method, apparatus and catalyst are suitable = in different embodiments for different uses. Further,

E: the invention is suitable in different embodiments for 3 producing carbon products and other products, such as 0 hydrogen.

N 35 The invention is not limited merely to the ex-

N amples referred to above; instead, many variations are possible within the scope of the inventive idea defined by the claims. i

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Claims

1. A method for producing at least carbon by a chemical reaction with a catalyst in a reactor, char - acterized in that the method comprises - supplying a reactant to the reactor comprising at least one catalyst surface inside the reactor for the chemical reaction and at least one space in the reactor, and the catalyst surface contains a metal catalyst; - performing the chemical reaction in the reactor in which the reactant is arranged into contact with the catalyst surface to form the carbon comprising an allotrope of carbon, and detaching nano-scale metal particles from the catalyst surface by the formed carbon; and - continuating the chemical reaction in the space of the reactor and growing an amount of the carbon by the formed carbon which comprises the detached nano-scale metal particles to form a carbon compo- nent.

2. The method according to claim 1, char - acterized in that the method further comprises pre-treating the catalyst surface for modifying the sur- face of the catalyst and/or for improving the activity of the catalyst, and the catalyst surface is pre-treated < at least by an acid, heat or their combination.

S 3. The method according to claim 1 or 2, o characterized in that the method further com- = 30 prises: acid-treating the catalyst surface using an = acid, and digesting and etching the metal catalyst dur- E: ing the acid treatment.

3 4. The method according to any one of claims 1 O to 3, characterized in that hydrogen is formed O 35 by the chemical reaction and recovered.

5. The method according to any one of claims 1 to 4, characterized in that the reactant is a hydrocarbon selected from the group of Ci-1o-alkanes, C,- isoralkenes, and C2-1o-alkynes.

6. The method according to any one of claims 1 to 5, characterized in that the carbon com- prising the allotrope of carbon is separated from the catalyst surface in the reactor and the chemical reac- tion is continued using the detached nano-scale metal particles attached to the formed carbon and using the catalyst surface.

7. The method according to any one of claims 1 to 6, characterized in that the reactor com- prises at least a first reactor space and second reactor space, and the carbon comprising the allotrope of carbon is formed in the first reactor space, and the formed carbon is moved from the first reactor space to the second reactor space in which the amount the carbon is grown.

8. The method according to any one of claims 1 to 7, characterized in that the allotrope of carbon comprises carbon nanofibers, carbon nanotubes, single wall carbon nanotubes, multiwalled carbon nano- tubes, carbon nano onions, carbon nano shells, carbon micro shells, amorphous carbon, graphene, graphite fi- bers and/or graphite.

< 9. The method according to any one of claims 1 S to 8, characterized in that the chemical re- 0 action is selected from the group consisting of a methane = 30 splitting, catalysed methane splitting, catalysed py- = rolysis, catalysed hydrocarbon pyrolysis, catalysed me- E: thane pyrolysis, catalytic hydrocarbon decomposition, 3 catalytic methane decomposition, thermocatalytic me- O thane decomposition, chemical vapor deposition, other O 35 reaction, or any combination thereof.

10. An apparatus for producing at least carbon by a chemical reaction with a catalyst in a reactor, characterized in that the apparatus comprises at least one reactor for performing the chemical reac- tion, at least one catalyst surface inside the reactor for the chemical reaction and at least one space in the reactor for collecting the carbon, and the catalyst sur- face contains a metal catalyst, wherein a reactant is arranged into contact with the catalyst surface to form the carbon comprising an allotrope of carbon in the reactor and to detach nano-scale metal particles from the catalyst surface by the formed carbon, and the chem- ical reaction is arranged to continue in the space of the reactor for growing an amount of the carbon by the formed carbon which comprises the detached nano-scale metal particles to form a carbon component.

11. The apparatus according to claim 10, characterized in that the space of the reactor is a reactor chamber.

12. The apparatus according to claim 10 or 11, characterized in that the reactor comprises at least a first reactor space and second reactor space, and the carbon comprising the allotrope of carbon is formed in the first reactor space, and the formed carbon is arranged to move from the first reactor space to the second reactor space in which the amount the carbon is < grown. S

13. The apparatus according to any one of 0 claims 10 to 12, characterized in that the = 30 apparatus comprises a reactor comprising at least one catalyst element, reactor comprising at least one cata- : lyst wall, vertical reactor, tube reactor, pyrolysis re- 3 actor, fluidized reactor, fixed reactor, fixed bed reac- O tor, rotary kiln reactor or any combination thereof as O 35 the reactor.

14. A catalyst for a chemical reaction forming at least carbon, characterized in that the catalyst comprises at least one catalyst surface, which contains a metal catalyst for the chemical reaction to form the carbon comprising an allotrope of carbon, and nano-scale metal particles are arranged to detach from the catalyst surface by the carbon, and a structure of the catalyst is two-dimensional or three-dimensional.

15. The catalyst according to claim 14, characterized in that the metal catalyst com- prises one or more catalytically active metals selected from the group consisting of nickel, copper, iron, al- uminium, titanium, cobalt, manganese, chromium, sili- con, carbon or an oxide thereof, or any combination thereof.

16. The catalyst according to claim 14 or 15, characterized in that the nano-scale metal par- ticles are attached to the formed carbon comprising at least carbon nanofibers, carbon nanotubes, single wall carbon nanotubes, multiwalled carbon nanotubes, carbon nano onions, carbon nano shells, carbon micro shells, amorphous carbon, dJraphene, graphite fibers and/or graphite to form an additional catalyst composite for continuating the chemical reaction.

17. The catalyst according to any one of claims 14 to 16, characterized in that the catalyst < comprises a reaction space in which the chemical reaction S is performed, and the catalyst surface is arranged inside Oo the reaction space. = 30

18. The catalyst according to any one of claims = 14 to 17, characterized in that the catalyst E is formed by printing, coating, depositing, extruding, 3 rolling, cutting, laser cutting or any combination O thereof. O 35

19. The catalyst according to any one of claims 14 to 18, characterized in that the catalyst comprises a honeycomb structure, lattice structure, mesh structure, netting, grid structure, knitted structure, spiral structure, screw structure, tube structure, rod structure, plate structure, other structure through which gas can flow, or other suitable structure.

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