Process and reactor for producing one or more products

Abstract

A feed gas, such as natural gas, is introduced into the mixing chamber. For example, a combustible gas is introduced into the combustion chamber while the feed gas is introduced. Thereafter, the combustible gas is ignited such that the combustible gas flows into the mixing chamber via one or more fluid flow paths between the combustion chamber and the mixing chamber and mixes with the feed gas. Mixing of the combustible gas with the feed gas produces one or more products.

Description

Technical Field

[0001] The present disclosure relates to a method and associated reactor for producing one or more products, for example, by cracking a feed gas, such as natural gas. Background Art

[0002] Natural gas (CH 4 Chemical cracking is the separation of natural gas into its carbon (C) and hydrogen (H 2 ) is a constituent component of hydrogen. Conventional methods of hydrogen generation, such as steam methane reforming (SMR), result in large amounts of diluted CO 2 emissions, which may require expensive post-reforming purification to isolate. As a result, the SMR generates 2 Produces approximately 8 to 10 tons of CO 2 . CO 2 Adding purge to an SMR flue gas stream is generally cost-prohibitive unless the penalty for CO2 emissions is increased to a critical point.

[0003] There are other methods of thermal decomposition to produce hydrogen and solid carbon, such as hot and liquid metal pyrolysis and plasma pyrolysis. These processes are usually tailored to maximize the production of solid carbon for the relevant carbon markets and are widely used in these industries.

[0004] Thermal cracking of natural gas is typically a constant pressure, steady flow process whereby natural gas is heated until it reaches the temperature required to begin forming hydrogen and carbon. At this point, the temperature is maintained for a certain amount of time to complete the equilibrium reaction. Assuming a constant pressure of 1 ATM, the time required for methane conversion decreases as the temperature increases (e.g. Figure 1 Shown - Drawings obtained from Kinetic Model of Homogeneous Thermal Decomposition of Methane and Ethane, Kinetic Model of Homogeneous Thermal Decomposition of Methane and Ethane, Maryan Younessi-Sinaki, Edgar A, Matida, Feridun Hammullahpur, Carleton University, Department of Mechanical and Aerospace Engineering, 1125 Colonel By Drive, Ottawa, ON K1S 5B6, Canada, the entire contents of which are incorporated herein by reference).

[0005] In such steady flow reactors, the carbon that forms tends to accumulate on the surface of the reactor, eventually becoming so thick that it impairs reactor performance. Mechanical scraping processes or burning the carbon off the surface by introducing air into the reactor are two common means of cleaning the reactor. Mechanical scraping is difficult to implement and may not remove hard carbon deposits. Burning the carbon off with air produces large amounts of CO2 Emissions, which are undesirable. Therefore, it is highly desirable not to form carbon on the surface in the first place, and to send the produced carbon to downstream processes.

[0006] Furthermore, shorter reaction times are required to reduce the size of the reactor, but this requires very expensive high temperatures and exotic materials. To try and overcome this, catalysts are added to the reactor that have the effect of lowering the reaction temperature. However, carbon buildup now also occurs on the surface of the catalyst, which over time deactivates and requires a reactivation process or replacement. Both options are expensive and increase the complexity of the process.

[0007] Liquid medium reactors (such as liquid metal reactors) involve a thermal process whereby natural gas is bubbled through a tower of high temperature liquid (such as liquid metal or salt). Since this is a constant pressure, steady flow process, the same temperature-dependent reaction rate as described above is applied. The benefit of this process is that, since the hydrogen bubbles produced come out of the top of the reactor tower and the carbon floats on the surface of the liquid medium, it can theoretically be skimmed off, thereby simplifying the separation of hydrogen and carbon. In some embodiments, liquid metal alloys that provide a catalytic effect and reduce the reaction temperature have been determined. However, in all cases, carbon accumulation at the top of the reactor remains a problem, and the use of a molten medium increases the complexity, material challenges, and cost of the reactor.

[0008] For most thermal processes, the energy required to heat the reactor and maintain the process is usually provided by burning some excess natural gas with air. This flue gas converts CO 2 released into the atmosphere and contributes to global warming. In some cases, excess carbon buildup and / or hydrogen can also be used to provide reaction heat.

[0009] Plasma reactors pass natural gas through a high temperature plasma generated by electricity at a constant pressure. The plasma can be generated by using, for example, electrodes or microwaves. Carbon buildup is still a problem in these reactors, but less so than in thermal reactors because the high temperature plasma is confined to a very small area. Unlike thermal reactors, plasma reactors rely solely on electricity as energy input. Compared to thermal systems, the electricity cost of the input energy is much higher than the electricity cost of natural gas, and therefore the resulting production cost of hydrogen and methane is much higher.

[0010]

[0006] Therefore, there is a need in the art for a natural gas cracking process that uses thermal energy that has lower capital costs and is less susceptible to carbon buildup problems. Summary of the invention

[0011] In general, the present disclosure relates to, but is not limited to, the use of dynamic gas compression and mixing to generate the pressure and temperature required for the thermal decomposition of natural gas to crack natural gas into carbon (C) and hydrogen (H 2 ) components. The goal of the process is to optimize the process for hydrogen production and recover solid carbon as a second value stream while minimizing carbon greenhouse emissions. When paired with a direct carbon fuel cell (DCFC), the carbon product can be used to generate electricity and the pure product stream CO 2 Suitable for storage (see Figure 2 ). The result is low-cost “clean” hydrogen.

[0012] According to a first aspect of the present disclosure, a method for producing one or more products is provided, comprising: introducing a raw gas into a mixing chamber, wherein the raw gas includes one or more gases; introducing a combustible gas into a combustion chamber, wherein the combustible gas includes one or more gases; and thereafter, igniting the combustible gas so that the combustible gas flows into the mixing chamber via one or more fluid flow paths between the combustion chamber and the mixing chamber and mixes with the raw gas, wherein energy is transferred from the combustible gas to the raw gas, thereby producing one or more products.

[0013] The raw gas and the combustible gas may be introduced in a manner such that the raw gas does not substantially mix with the combustible gas, or undergoes little or negligible mixing, prior to ignition.

[0014] The method may also include stopping further production of one or more products.

[0015] The method may further include preheating the raw material gas prior to introducing the raw material gas into the mixing chamber.

[0016] The method may further include preheating the combustible gas prior to introducing the combustible gas into the combustion chamber.

[0017] The ratio of the volume of the mixing chamber to the volume of the combustion chamber may be less than or equal to about 10:1.

[0018] The ratio of the length of the mixing chamber to the diameter of the mixing chamber may be less than or equal to about 30:1.

[0019] The raw gas may include natural gas. The raw gas may include a mixture of natural gas and recycled gas. The recycled gas may include one or more of: natural gas; hydrogen; carbon monoxide; and carbon dioxide.

[0020] The combustible gas may contain an oxidant. The oxidant may include one or more of oxygen and air. The combustible gas may include CH 4 and O 2The combustible gas may include a mixture of a recycle gas and an oxidant. The recycle gas may include one or more of: natural gas; hydrogen; carbon monoxide; and carbon dioxide.

[0021] The combustible gas may be introduced into the combustion chamber simultaneously with the introduction of the raw gas into the mixing chamber.

[0022] The combustible gas may be introduced into the combustion chamber at a pressure equal to the pressure at which the raw gas is introduced into the mixing chamber.

[0023] The one or more products may include one or more of hydrogen and carbon.

[0024] The one or more products may include one or more of hydrogen and carbon monoxide.

[0025] The one or more products may include one or more of hydrogen, nitrogen, and carbon. The hydrogen and nitrogen may be used to produce ammonia.

[0026] Stopping further production of one or more products may include reducing the pressure within the mixing chamber. The pressure within the mixing chamber may be reduced sufficiently quickly, such as by at least 50% in less than 1 second, to inhibit carbon buildup in the mixing chamber.

[0027] The pressure wave generated by the combustion of the combustible gas can suppress carbon deposition in the mixing chamber.

[0028] Energy can be transferred from the combustible gas to the raw gas via dynamic compression and mixing of the gases.

[0029] After ignition but before the combustible gas is mixed with the raw gas, the temperature in the combustion chamber can be about 90 ATM and -3,700 K, for example in pure O 2 as an oxidant and the recirculated gas as a combustible gas.

[0030] After the combustible gas is mixed with the raw gas and before one or more products are produced, at least a portion of the mixture of raw gas and combustible gas can be transferred to the third chamber. Thus, while the user is waiting for one or more products to be produced in the third chamber, the combustion chamber and the mixing chamber can be replenished with fresh combustible gas and raw gas.

[0031] In another aspect of the present disclosure, a raw gas reactor is provided, comprising: a mixing chamber; a combustion chamber; a valve for controlling gas flow into and out of the mixing chamber and the combustion chamber; an igniter; and one or more controllers, the controller being configured to perform the following method, the method comprising: controlling the valve to introduce a feed gas into the mixing chamber, wherein the raw gas comprises one or more gases; controlling the valve to introduce a combustible gas into the combustion chamber, wherein the combustible gas comprises one or more gases; thereafter, controlling the igniter to ignite the combustible gas so that the combustible gas flows into the mixing chamber via one or more fluid flow paths between the combustion chamber and the mixing chamber, and mixes with the raw gas, wherein energy is transferred from the combustible gas to the raw gas, thereby producing one or more products.

[0032] The raw gas and the combustible gas may be introduced in such a manner that the raw gas is not substantially mixed with the combustible gas.

[0033] The method may also include controlling the valve to stop further production of one or more products.

[0034] The combustion chamber may be located within the mixing chamber. The combustion chamber may be offset from the longitudinal axis of the mixing chamber.

[0035] The combustion chamber may be located outside the mixing chamber.

[0036] The combustion chamber may include one or more holes formed therein.

[0037] The raw gas reactor may comprise any of the features described in conjunction with the first aspect of the invention.

[0038] In another aspect of the present disclosure, a raw gas reactor is provided, comprising: a mixing chamber; a combustion chamber, the combustion chamber including one or more holes formed therein, wherein the one or more holes provide one or more fluid flow paths from the combustion chamber to the mixing chamber; a valve for controlling the flow of gas into and out of the mixing chamber and the combustion chamber; and an igniter.

[0039] The raw gas reactor may comprise any of the features described in conjunction with the first aspect of the invention.

[0040] Controlling the valve may include controlling the opening and / or closing of a single valve.Alternatively or in addition, controlling the valve may include a valve that rotates relative to the reactor (eg, using a motor).

[0041] In another aspect of the present disclosure, a system is provided, comprising: a plurality of raw material reactors, each reactor comprising: a mixing chamber; a combustion chamber; and an igniter; a valve for controlling the flow of gas into and out of the mixing chamber and the combustion chamber; and one or more controllers, the controller being configured to perform the following method, the method comprising, for each reactor: controlling the valve to introduce raw material gas into the mixing chamber, wherein the raw material gas comprises one or more gases; controlling the valve to introduce combustible gas into the combustion chamber, wherein the raw material gas comprises one or more gases; thereafter, controlling the igniter to ignite the combustible gas so that the combustible gas flows into the mixing chamber via one or more fluid flow paths between the combustion chamber and the mixing chamber and mixes with the raw material gas, wherein energy is transferred from the combustible gas to the raw material gas and one or more products are produced, wherein, for a given reactor, the method is performed asynchronously with at least one other reactor among the plurality of reactors.

[0042] For each reactor, the raw gas and the combustible gas may be introduced in such a manner that the raw gas is not substantially mixed with the combustible gas.

[0043] For each reactor, the method may further include controlling a valve to stop further production of the one or more products.

[0044] The plurality of reactors may be arranged radially around a central axis, and the system may further include a rotator configured to: rotate the plurality of reactors relative to a valve assembly including a valve around the central axis; or rotate the valve assembly including a valve relative to the plurality of reactors around the central axis. Thus, the valve assembly may rotate while the reactor is stationary, or the valve assembly may be stationary while the reactor is rotating. In some embodiments, the valve assembly and the reactor may even rotate simultaneously.

[0045] Controlling the valve may include controlling the opening and / or closing of a single valve.Alternatively or in addition, controlling the valve may include a valve that rotates relative to the reactor (eg, using a motor).

[0046] The system may comprise any of the features described in conjunction with the first aspect of the invention.

[0047] In another aspect of the present disclosure, a system is provided, comprising: one or more reactors of any of the above reactors; and one or more fuel cells coupled to the one or more reactors and configured to receive carbon produced by mixing a combustible gas with a raw gas.

[0048] The system may comprise any of the features described in conjunction with the first aspect of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0049] Embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings, in which:

[0050] Figure 1 is a graph of the mole fraction of hydrogen produced from methane at a pressure of 1 atmosphere at different temperatures and time constants;

[0051] Figure 2 shows a combination of natural gas dissociation and a carbon fuel cell for producing hydrogen, electricity, and pure carbon dioxide according to an embodiment of the present disclosure;

[0052] Figure 3 is a schematic diagram of a system for cracking natural gas according to an embodiment of the present disclosure;

[0053] Figure 4A and Figure 4B shows different arrangements of mixing chambers and combustion chambers according to embodiments of the present invention;

[0054] Figure 5 is a schematic diagram of a method for cracking natural gas according to an embodiment of the present disclosure;

[0055] Figure 6 shows different configurations of systems including asynchronously operated bundled reactors according to embodiments of the present invention;

[0056] Figure 7 shows a bundled reactor rotating about a fixed valve according to an embodiment of the present disclosure;

[0057] Figure 8 is a schematic block diagram of a combustion chamber and a mixing chamber and a third chamber according to an embodiment of the present disclosure, the mixing chamber being used to provide a mixture of a raw gas and a combustible gas, the combustible gas and raw gas mixture being directed to the third chamber, and one or more products being produced from the mixture in the third chamber;

[0058] Fig. 9 is a schematic block diagram of a combustion chamber and a mixing chamber according to an embodiment of the present disclosure, the mixing chamber being used to provide a mixture of a raw gas and a combustible gas, and wherein one or more products are produced from the mixture;

[0059] Fig.10 is a schematic block diagram of a combustion chamber and a mixing chamber for providing a mixture of a raw gas and a combustible gas, and wherein one or more products are produced from the mixture, and wherein recycled gas is used to provide heat energy for the process, according to an embodiment of the present disclosure;

[0060] Fig.11 is a schematic diagram of a combustion chamber located within a mixing chamber according to an embodiment of the present invention;

[0061] Fig.12 is a schematic diagram of a combustion chamber located outside a mixing chamber according to an embodiment of the present invention;

[0062] Fig.13 shows a combustion chamber arranged within a mixing chamber according to an embodiment of the present disclosure; and

[0063] Fig.14 A multi-reactor bundle with fixed reactors and rotary valves is shown according to an embodiment of the present disclosure. DETAILED DESCRIPTION

[0064] The present disclosure seeks to provide improved methods and reactors for producing one or more products. Although various embodiments of the present invention are described below, the present invention is not limited to these embodiments, and variations of these embodiments may well fall within the scope of the present invention, which will only be limited by the appended claims.

[0065] When used in conjunction with the terms "comprising" or "including" in the claims and / or the specification, the word "a" or "an" may mean "one", but it is also consistent with the meaning of "one or more", "at least one", and "one or more than one", unless the context clearly indicates otherwise. Similarly, the word "another" may mean at least a second or more, unless the context clearly indicates otherwise.

[0066] As used herein, the terms "coupled," "coupled," or "connected" may have several different meanings, depending on the context in which the terms are used. For example, the terms coupled, coupled, or connected may have mechanical or electrical meanings. For example, as used herein, the terms coupled, coupled, or connected may indicate that two elements or devices are directly connected to each other, or are connected to each other via electrical elements, electrical signals, or mechanical elements via one or more intermediate elements or devices, depending on the particular context. When used in association with a list of items, the term "and / or" herein refers to any one or more of the items that comprise the list.

[0067] As used herein, reference to "about" or "approximately" a number or "substantially" equal to a number means within + / - 10% of that number.

[0068] In general, according to embodiments of the present disclosure, a super-rich pulse pyrolysis process for producing hydrogen-rich gas and / or carbon products from a natural gas feedstock is described. The process can be competitive with SMR for large-scale hydrogen production.

[0069] According to an embodiment of the present disclosure, a pulse reaction process using an unstable, constant volume is described to produce hydrogen and carbon products from a natural gas-based feedstock. Separate chambers for the combustible gas and oxidant provide energy for the reaction and are directly transferred to the feedstock mixing chamber by gas dynamic compression and rapid mixing heat energy exchange via direct contact. In the following discussion, air is used as the oxidant; however, other oxidants, such as pure oxygen, can be used in the process. In addition, the raw gas and the combustible gas may include the same gas or gas mixture or may include different gases or gas mixtures. In some embodiments, the combustible gas may include a recycled gas mixture.

[0070] The reactor comprises a mixing chamber and a combustion chamber. These chambers are connected via multiple channels that are always open. In some embodiments, the reactor comprises a perforated tube (combustion chamber) within a larger solid tube (mixing chamber); see Figure 3 and 4A In other embodiments, the combustion chamber may be external to the mixing chamber (eg, Figure 4B External valves provide feedstock, oxidant, and combustible gas (shown as CH 4 ) as well as discharged hydrogen, carbon and other gases produced during the reaction.

[0071] Go to Figure 5, at the beginning of the cycle, the mixing chamber is filled with the product of the previous reaction cycle. The mixing chamber is filled with a mixture of the raw material reaction product plus a portion of the combustion reaction product. The combustion chamber is mainly filled with the product of the combustion reaction. At 500, fresh raw materials and possibly some recycled product gases are introduced into the mixing chamber to replace the products of the previous cycle from the end of the mixing chamber. At the same time, a combustible gas / air mixture is introduced into the combustion chamber, so that the combustion products are discharged from the end of the combustion chamber. At 502, all inlet valves and outlet valves are closed, thereby generating a closed volume. At 504, the gas in the combustion chamber is then ignited, resulting in an increase in pressure and temperature in the combustion chamber. At 506, the passage between the combustion chamber and the mixing chamber allows the combustible gas product to enter the mixing chamber, thereby compressing the raw gas and increasing their pressure and temperature. In addition, the hot combustion chamber gas product mixes with the raw gas and thereby transfers its heat energy to the raw gas, thereby further increasing its temperature. The temperature and pressure of the resulting raw gas cause a reaction to occur. At 508, the reaction is allowed to proceed for a period of time to complete the desired reaction and develop the desired product. At 510, the pressure in the mixing chamber is quickly reduced by releasing the product to an external volume (not shown). The combustion product gases retained in the combustion chamber can be discharged together with the mixing chamber gas or discharged separately through a dedicated port. Reducing the pressure in the mixing chamber reduces the temperature and stops or quenches the reaction. Rapid decompression and expansion also have the desired effect of removing solid reaction products (such as carbon) from the reactor wall. In addition, the pressure wave generated by the combustion can strip carbon deposits from the reactor wall.

[0072] If the feedstock and the combustible gas are premixed, the mixture may not ignite because it is too rich. Therefore, the mixing chamber and the combustion chamber are distinct and separate before ignition so that no or preferably very little mixing occurs between the feedstock gas and the combustible gas.

[0073] Multiple reactor systems can be bundled together and operated slightly asynchronously from one another to produce continuous flow into and out of the reactor system. Valves can be stationary or rotating, such as Figure 6 In some embodiments, the reactor can rotate and the valve can remain stationary (see Figure 7 , from the wave rotor design method Figure 2 Modified from, with three steps including experimental verification, Chan Shining et al., Journal of Engineering for Gas Turbines and Power, December 2017, the entire contents of which are incorporated herein by reference).

[0074] Various parameters can be adjusted to enable the reactor to operate efficiently. The feed gas can be preheated to just below the temperature at which it begins to react before being introduced into the mixing chamber. Typical temperatures will be in the range of 600K to 1000K, depending on the feed composition and the operating pressure.

[0075] In addition, the introduced combustible gas / oxidant mixture may be preheated before entering the combustion chamber. Depending on the combustible gas used, typical temperatures will be in the range of 400K to 700K. Preheating the combustible gas / oxidant mixture may improve the efficiency of the process, so that more of the combustion energy is transferred to the reactants rather than used to heat the combustion products.

[0076] The volume ratio between the mixing chamber and the combustion chamber should be set so that the correct amount of energy contained in the combustion chamber is provided to the mixing chamber to produce the desired product. There should also be enough combustible gas product entering the mixing chamber to provide effective mixing. A volume ratio of less than 10:1 is generally desired. When using air as the oxidant, nitrogen may be beneficial as a non-reactive gas to increase the lower volume ratio and increase mixing. When using pure oxygen as the oxidant, another gas (such as CO 2 ) can provide the same benefits as nitrogen in air as an oxidant. 2 Introducing into the combustible gas mixture can result in greater solid carbon production.

[0077] The aspect ratio is important to obtain efficient energy transfer from the combustion chamber to the mixing chamber. Short, large diameter reactors tend to have poor mixing, while long, narrow reactors will face challenges in introducing feedstock and combustible gases into the reactor along its length. An aspect ratio of less than 30:1 is generally desired.

[0078] According to some embodiments, the reactor uses methane (or natural gas) as the feed gas in addition to some recycled product gas, and uses a recycled gas / oxidant mixture as the combustible gas. The reactor can be designed and operated to maximize the production of hydrogen and solid carbon in the reaction product stream. The reactor can include a combustion chamber within a mixing chamber, which is a perforated tube. The perforated combustion chamber can be offset from the center of the mixing chamber and combined with the walls of the mixing chamber to provide structural integrity and support, such as Fig.13 The mixing chamber / combustion chamber volume ratio may be less than or equal to 10:1, and the aspect ratio may be 10:1. In some embodiments, the mixing chamber / combustion chamber volume ratio may be about 6:1, and in some embodiments, the mixing chamber / combustion chamber volume ratio may be about 3.5:1.

[0079] like Fig.14As shown, multiple reactor tubes can be arranged with external rotary valves to provide flow and sequencing of all feedstocks, combustible gases and reaction products. Separate ports can exhaust the combustion chamber combustion products.

[0080] The reactor can be operated at a sufficiently high pressure that the resulting hydrogen can be purified using standard pressure swing absorption techniques. According to some embodiments, the product gas (such as unreacted methane (CH 4 ), carbon monoxide (CO), and some hydrogen) are recycled and mixed with more methane to produce the feed gas mixture to the reactor. The combustible gas mixture includes, in addition to (in the case of an air-blown reactor) CO 2 CO removed by the removal system 2 In some embodiments, in addition to CH 4 , CO and H 2 In addition, the recirculated gas mixture flowing to both the combustion chamber and the mixing chamber also contains CO 2 The raw gas mixture and the combustible gas mixture are preheated to -900K and -600K, respectively, from heat energy recovered from the reactor product stream via a multi-stream heat exchanger. In an alternative embodiment, the mixing chamber / combustion chamber volume ratio is 3.5:1, and a methane (or natural gas) / air mixture is used for the combustible gases.

[0081] A detailed description of embodiments of the present disclosure will now be provided.

[0082] refer to Figure 8 , the combustible gas 10 and the oxidant gas 20 enter the combustion mixture conditioning and control system 30, which regulates the combustible gas mixture 31 to the correct temperature and pressure required for the chamber 60. The raw gas 40 and the recirculated gas mixture 91 enter the raw mixture conditioning and control system 50, which regulates the raw mixture 51 to the correct temperature and pressure required for the chamber 60. In some embodiments, the recirculated gas mixture is not available, and only the raw gas 40 enters the raw mixture conditioning and control system 50.

[0083] The chamber 60 is a constant volume device that uses the combustion energy from the regulated combustible gas mixture 31 to raise the pressure and temperature of the regulated feedstock mixture 51 to a reaction-ready level. A combustion product gas mixture 67, which mainly includes the combustion products of the regulated combustible gas mixture 31, can be discharged from the chamber 60. The gas mixture 61 ready for reaction enters the reactor 70, whereupon it is maintained until the gas mixture is converted into a reaction product mixture 71 in a constant volume endothermic reaction. The constant volume reaction is an unstable process that operates in batch mode and requires control of flow timing. This is achieved by flow control in the regulating system 30, 50 and separation and control system 80.

[0084] The reaction product mixture 71 enters the product separation and control system 80, which stops the reaction in the reactor 70 by reducing the pressure and temperature of the desired reaction product mixture 71, and separates and / or purifies the individual product components 81, 82, unwanted products 83, and the recycle gas mixture 84. The recycle gas mixture 84 enters the pre-conditioning recycle gas system 90, where the recycle gas mixture 84 is pre-conditioned to the desired temperature and pressure, and flows to the feed mixture conditioning and control system 50.

[0085] In some embodiments, the combustible gas 10 and the feed gas 40 are natural gas, and the oxidant gas 20 is air. The desired reaction in the reactor 70 is methane pyrolysis, generally given by the following equation:

[0086] CH 4 (Methane) + Energy → C (Carbon) + 2H 2 (hydrogen)

[0087] The single product 81 is hydrogen, the single product 82 is carbon, and the unwanted products 83 are primarily carbon dioxide, nitrogen and water. The recycle gas mixture 84 comprises primarily unreacted natural gas, hydrogen, nitrogen and carbon monoxide.

[0088] Fig. 9 The system in is similar to Figure 8 The system is similar to that in FIG. 1 , except that the chamber 60 and the reactor 70 are combined into the constant volume reactor 62 .

[0089] Fig.10 Similar to Fig. 9 , but a portion of the recirculated mixture 84 is regulated in a pre-regulated recirculated gas regulator 90 and sent to the combustible gas regulator and control system 30 to offset the required amount of combustible gas 10.

[0090] Fig.11 A cross-sectional view of a chamber 60 or a constant volume reactor 62 is shown. In this description, it is shown as a constant volume reactor 62.

[0091] Constant volume reactor 62 includes a combustion volume 65 contained within a combustion chamber 63. Combustion chamber 63 is surrounded by a reactor volume 64 contained within a reaction chamber 68. A passage 66 connects combustion volume 65 to reactor volume 64. Although combustion chamber 63 is shown as being located in the center of reaction chamber 68, combustion chamber 63 may be located anywhere in reaction chamber 68, including against an outer wall 69 of reaction chamber 68.

[0092] The regulated combustible gas mixture 31 enters the combustion chamber 63 through the combustible gas mixture valve 32 and passage 33, and any combustion product gas mixture 67 present in the combustion volume 65 is removed from the reactor 62 via passage 74 and combustion product valve 75. The regulated raw gas mixture 51 enters the mixing chamber 68 through the raw gas mixture valve 52 and passage 53, and the desired reaction product mixture 71 in the reactor volume 64 is removed from the reactor 62 via passage 73 and product valve 72. Both the regulated combustible gas mixture 31 and the regulated raw gas mixture 51 can enter the constant volume reactor 62 at the same time and at the same pressure, so that there is very little mixing via passage 66.

[0093] Once substantially all of the combustible gas mixture 67 and the desired product mixture 71 are removed from the reactor 62, the combustion product valve 75 and the product valve 72 are closed. Once the desired reactor pressure is reached, the combustible gas mixture valve 32 and the raw gas mixture valve 52 are closed, creating a closed volume in the reactor 62. The igniter 100 generates ignition energy 101 that allows the conditioned combustible gas mixture 31 in the combustion chamber 63 to burn at an elevated temperature and pressure in an exothermic reaction that produces a combustion product gas mixture 67. Due to the pressure differential created between the combustion chamber 63 and the mixing chamber 68, a portion of the combustible gas mixture 67 enters the reactor volume 64, thereby compressing the raw gas mixture 51 to a higher pressure. At the same time, portions of the hot combustible gas mixture 67 mix and heat the raw gas mixture 51 by conduction, convection, and radiation. The raw gas mixture 51 is now at an elevated temperature and pressure, which creates conditions for an endothermic reaction to occur. The constant volume reactor 62 remains as a closed volume until the endothermic reaction has proceeded long enough to produce the desired product mixture 71. Once conditions are reached, the product valve 72 and the combustion product valve 75 are opened, which reduces the pressure and temperature, stopping the endothermic reaction. The process is then repeated.

[0094] Fig.12An embodiment of a chamber 60 or constant volume reactor 62 is shown having a combustion chamber 63 external to a mixing chamber 68. The combustion volume 65 is connected to the reactor volume 64 via a plurality of channels 68. If desired, multiple igniters may be positioned along the combustion chamber 63 to produce specific combustion conditions. If the combustion chamber 63 is positioned close to the reaction chamber wall 69, multiple igniters may also be positioned at the reactor volume 64. Fig.11 In a constant volume reactor 62.

[0095] Fig.13 An isometric view of an embodiment of a chamber 60 or constant volume reactor 62 is shown in which a combustion chamber 63 is directly bonded to a reaction chamber wall 69 of a reaction chamber 68. Bonding the combustion chamber 63 directly to the reactor chamber wall 69 provides structural support and alignment for the combustion chamber 63 and creates a substantially one-piece chamber 60 or constant volume reactor 62.

[0096] To create a quasi- or semi-continuous flow system, multiple chambers 60 or constant volume reactors 62 may be arranged together and operated asynchronously so that each chamber or reactor undergoes Fig.11 Different parts of the method described in .

[0097] Fig.14 An embodiment of a multi-tube reactor 110 is shown, wherein Fig.14 The plurality of single constant volume reactors 62 shown in FIG. 1 are arranged in a circular pattern. The conditioned combustible gas mixture 31 enters the multi-tube reactor 110 via passage 34 into the plenum 35. The conditioned feed gas mixture 51 enters the multi-tube reactor 110 via passage 54 into the plenum 55. The timing of the conditioned combustion and conditioned feed gas mixtures entering the multi-tube reactor 110 is controlled by an inlet rotary valve 120, which is part of a rotary valve assembly 121. The inlet rotary valve 120 performs the same Fig.11 The timing of the combustion product gas mixture 67 and the desired product mixture 71 leaving the multi-tube reactor 110 is controlled by the outlet rotary valve 122, which is part of the rotary valve assembly 121. The outlet rotary valve 122 performs the same functions as described in the previous section. Fig.11 The combustion product valve 72, passage 73, raw product valve 75 and passage 74 have the same functions as described in the above.

[0098] The combustion product gas mixture 67 from each constant volume reactor 62 is collected in the combustion product plenum 123 and distributed to the outside of the multi-tube reactor 110 via the passage 125. The product mixture 71 from each constant volume reactor 62 is collected in the product plenum 124 and distributed to the outside of the multi-tube reactor 110 via the passage 126.

[0099] Although the present invention is presented primarily in the context of cracking of a raw gas, the present invention extends to other methods of producing one or more products from a raw gas. For example, synthesis gas (H 2 and CO) can be produced by adjusting one or more parameters of the process so that the combustible gas reacts with the raw gas (in addition to mixing). For example, the ratio of oxidant to recycle gas in the combustible gas can be increased to increase the pressure and temperature of the combustible gas immediately after ignition, thereby causing a suitable reaction between the combustible gas and the raw gas.

[0100] Although the present disclosure has been described in conjunction with specific embodiments, it should be understood that the present disclosure is not limited to these embodiments, and that changes, modifications and variations of these embodiments may be made by those skilled in the art without departing from the scope of the present invention. It is further contemplated that any aspect or any portion of an embodiment discussed in this specification may be implemented or combined with any other aspect or any portion of an embodiment discussed in this specification.

Claims

1. A method for decomposing a raw gas in a raw gas reactor, comprising: introducing a raw gas into a mixing chamber of the raw gas reactor; introducing a combustible gas into a combustion chamber of the raw gas reactor, wherein the combustion chamber is connected to the mixing chamber; combusting the combustible gas in the combustion chamber to form one or more combustion product gases, wherein the one or more combustion product gases flow into the mixing chamber and mix with the feed gas, and wherein, due to the mixing of the one or more combustion product gases with the feed gas, energy is transferred from the one or more combustion product gases to the feed gas, thereby causing a chemical reaction to decompose the feed gas and produce one or more reaction products; extracting a mixed product stream comprising one or more reaction products from the mixing chamber; and At least a portion of the mixed product stream is recycled to the feed gas reactor.

2. The method according to claim 1, wherein: The mixed product stream comprises carbon; and The method also includes separating at least some carbon from the mixed product stream.

3. The method according to claim 1 or 2, wherein: The mixed product stream comprises hydrogen; and The method also includes separating at least some of the hydrogen from the mixed product stream.

4. The method of claim 3, wherein separating the hydrogen comprises using pressure swing absorption.

5. The method according to any one of claims 1, 2 or 4, wherein: The mixed product stream comprises carbon and hydrogen; and Recycling at least a portion of the mixed product stream comprises: separating at least some carbon and at least some hydrogen from the mixed product stream to form a recycle gas mixture; and The recycled gas mixture is recycled to the feed gas reactor.

6. The method of claim 5, wherein recycling the recycle gas mixture comprises: adjusting the recycle gas mixture to a desired temperature and pressure; and The conditioned recycle gas mixture is recycled to the feed gas reactor.

7. The method of claim 5, wherein recycling the recycle gas mixture comprises: mixing a first portion of the recycle gas mixture with an oxidant; mixing a second portion of the recycle gas mixture with a source of the feed gas; and A mixture of the oxidant and the first portion of the recycle gas mixture and a mixture of the feed gas and the second portion of the recycle gas mixture are recycled to the feed gas reactor. The method according to claim 7 , wherein the sum of the first part and the second part is 1.

9. The method of claim 7, wherein recycling the mixture comprises: introducing a mixture of an oxidant and a first portion of a recirculated gas mixture into the combustion chamber; and A mixture of the raw gas and the second portion of the recycle gas mixture is introduced into a mixing chamber.

10. The method of claim 9, wherein introducing the mixture of the oxidant and the first portion of the recirculated gas mixture into the combustion chamber comprises: adjusting the mixture of the oxidant and the first portion of the recycle gas mixture to a desired temperature and pressure; and The conditioned mixture is introduced into the combustion chamber.

11. The method of claim 9, wherein introducing the mixture of the raw gas and the second portion of the recycle gas mixture into the mixing chamber comprises: adjusting the mixture of the feed gas and the second portion of the recycle gas mixture to a desired temperature and pressure; and The conditioned mixture is introduced into the mixing chamber.

12. The method according to any one of claims 1, 2 and 4, wherein burning the combustible gas comprises igniting the combustible gas.

13. The method of any one of claims 1, 2 and 4, wherein the feedstock is decomposed in a constant volume reaction process.

14. A system comprising: The raw gas reactor includes: Mixing chamber; a combustion chamber connected to the mixing chamber; and at least one igniter; Valves for controlling the flow of gases into and out of the mixing chamber and the combustion chamber; and A controller operable to: controlling the valve to introduce the raw material gas into the mixing chamber; controlling the valve to introduce combustible gas into the combustion chamber; controlling the at least one igniter to combust the combustible gas in the combustion chamber to form one or more combustion product gases, wherein the one or more combustion product gases flow into the mixing chamber and mix with the feed gas, and wherein, due to the mixing of the one or more combustion product gases with the feed gas, energy is transferred from the one or more combustion product gases to the feed gas, thereby causing a chemical reaction to decompose the feed gas and produce one or more reaction products; controlling the valve to extract a mixed product stream comprising one or more reaction products from the mixing chamber; and The valve is controlled to recycle at least a portion of the mixed product stream to the feed gas reactor.

15. The system of claim 14, wherein: The mixed product stream comprises carbon and hydrogen; The system also includes a carbon separator and a hydrogen separator for separating at least some carbon and at least some hydrogen from the mixed product stream to form a recycle gas mixture; and The controller is further operable to control the valve to recycle the recycle gas mixture to the feed gas reactor.

16. The system of claim 15, wherein the controller is further operable to control the valve to: mixing a first portion of the recycle gas mixture with an oxidant; mixing a second portion of the recycle gas mixture with a source of said feed gas; and A mixture of oxidant and the first portion of the recycle gas mixture and a mixture of feed gas and the second portion of the recycle gas mixture are recycled to the feed gas reactor.

17. The system of claim 16, wherein the sum of the first portion and the second portion is 1.

18. The system of claim 16 or 17, wherein the controller is further operable to control the valve to: introducing a mixture of an oxidant and a first portion of a recirculated gas mixture into the combustion chamber; and A mixture of the raw gas and the second portion of the recycle gas mixture is introduced into the mixing chamber.

19. The system of claim 18, wherein: The system also includes a combustion mixture conditioning and control system for conditioning the mixture of the oxidant and the first portion of the recirculated gas mixture to a desired temperature and pressure; and The controller is further operable to control the valve to introduce the conditioned mixture into the combustion chamber.

20. The system of claim 18, wherein: The system also includes a feed mixture conditioning and control system for conditioning the mixture of the feed gas and the second portion of the recycle gas mixture to a desired temperature and pressure; and The controller is further operable to control the valve to introduce the conditioned mixture into the mixing chamber.

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