WO2024187267A1

WO2024187267A1 - Decomposing a feedstock gas using an energy fluid

Info

Publication number: WO2024187267A1
Application number: PCT/CA2024/050239
Authority: WO
Inventors: Kenneth William Kratschmar
Original assignee: Ekona Power Inc.
Priority date: 2023-03-10
Filing date: 2024-02-27
Publication date: 2024-09-19

Abstract

A method of decomposing a feedstock gas includes introducing the feedstock gas into a reaction chamber, introducing an energy fluid into a heating chamber connected to the reaction chamber, and heating, in a constant-volume process, the energy fluid in the heating chamber without combusting the energy fluid. As a result of the heating, the heated energy fluid flows from the heating chamber to the reaction chamber and mixes with the feedstock gas. As a result of the mixing, energy is transferred from the heated energy fluid to the feedstock gas and causes the feedstock gas to decompose.

Description

DECOMPOSING A FEEDSTOCK GAS USING AN ENERGY FLUID

Field

[0001] The present disclosure relates to thermal pyrolysis and in particular to decomposing a feedstock gas using an energy fluid.

Background

[0002] Thermal pyrolysis is a method by which a feedstock gas, such as a hydrocarbon, is decomposed without oxygen into its constituent elements (in the case of a hydrocarbon, carbon and hydrogen). The decomposition is triggered by sufficiently raising the temperature of the feedstock gas to a point at which the chemical bonds of the elements of the feedstock gas break down.

[0003] The energy required to raise the temperature of the feedstock and to maintain the endothermic pyrolysis reaction can come from burning a fuel with an oxidant to heat the walls of a reaction chamber in which is located the feedstock. In this manner, the feedstock is indirectly heated through the reactor walls. However, this requires a reactor able to withstand very-high operating temperatures, and such reactors generally require the use of exotic materials which can be extremely costly.

[0004] Alternatively, the products of the combustion of the fuel can be directly mixed with the feedstock to raise its temperature and provide the necessary endothermic energy of reaction. While this eliminates the requirement of a high-temperature reactor, the products of combustion may be difficult to separate from the resulting decomposed feedstock. In addition, the products of combustion may be greenhouse gases which may add to the overall emission intensity of the process.

Summary

[0005] According to a first aspect of the disclosure, there is provided a method of decomposing a feedstock gas, comprising: introducing the feedstock gas into a reaction chamber; introducing an energy fluid into a heating chamber connected to the reaction chamber; and heating, in a constant-volume process, the energy fluid in the heating chamber without combusting the energy fluid, wherein, as a result of the heating, the heated energy fluid flows from the heating chamber to the reaction chamber and mixes with the feedstock gas, and wherein, as a result of the mixing, energy is transferred from the heated energy fluid to the feedstock gas and causes the feedstock gas to decompose.

[0006] The volume of the heating chamber may define a closed volume during the constantvolume process.

[0007] The combined volumes of the reaction chamber, the heating chamber, and any passageways connecting the reaction chamber to the heating chamber may define a closed volume during the constant-volume process.

[0008] Heating the energy fluid without combusting the energy fluid may comprise heating the energy fluid in the absence of any oxidant.

[0009] Heating the energy fluid may comprise heating the energy fluid using plasma heating.

[0010] Heating the energy fluid may comprise heating the energy fluid using one or more: resistance heating; microwave heating; induction heating; photon heating; infrared heating; and heat generated from the combustion of a fuel.

[0011] The feedstock gas may comprise one or more first compounds. The energy fluid may comprise one or more second compounds selected so that, during decomposition of the feedstock gas, the one or more second compounds chemically react with the one or more first compounds to produce one or more reaction products.

[0012] The energy fluid may be inert such that, during decomposition of the feedstock gas, the energy fluid does not chemically react with the feedstock gas.

[0013] The decomposition of the feedstock gas may produce one or more reaction products. The method may further comprise recycling at least some of the reaction products to the heating chamber for use as the energy fluid in a subsequent reaction cycle.

[0014] According to a further aspect of the disclosure, there is provided a system comprising: a feedstock gas reactor comprising: a reaction chamber; and a heating chamber connected to the reaction chamber; a heat source; valving and one or more compressors for allowing fluids to flow into and out of the reaction chamber and the heating chamber; and a controller comprising circuitry and configured to: control the valving and the one or more compressors to introduce a feedstock gas into the reaction chamber; control the valving and the one or more compressors to introduce an energy fluid into the heating chamber; control the heat source to heat, in a constant-volume process, the energy fluid in the heating chamber without combusting the energy fluid, wherein, as a result of the heating, the heated energy fluid flows from the heating chamber to the reaction chamber and mixes with the feedstock gas, and wherein, as a result of the mixing, energy is transferred from the heated energy fluid to the feedstock gas and causes the feedstock gas to decompose.

[0015] The heat source may comprise an electrical power supply and electrodes for generating an electrical current.

[0016] The controller may be further configured to control the valving and the one or more compressors to recycle at least some of one or more reaction products, produced as a result of the decomposition, to the heating chamber for use as the energy fluid in a subsequent reaction cycle.

[0017] This summary does not necessarily describe the entire scope of all aspects. Other aspects, features, and advantages will be apparent to those of ordinary skill in the art upon review of the following description of specific embodiments.

Drawings

[0018] Embodiments of the disclosure will now be described in detail in conjunction with the accompanying drawings:

[0019] FIG. 1 is a schematic diagram of a feedstock gas being decomposed by mixing with a heated energy fluid, according to an embodiment of the disclosure; and

[0020] FIG. 2 is a flow diagram of a method of decomposing a feedstock gas using an energy fluid, according to an embodiment of the disclosure.

Detailed Description

[0021] The present disclosure seeks to provide novel methods and systems for decomposing a feedstock gas using an energy fluid. While various embodiments of the disclosure are described below, the disclosure is not limited to these embodiments, and variations of these embodiments may well fall within the scope of the disclosure which is to be limited only by the appended claims.

[0022] According to embodiments of the disclosure, there is described a method of feedstock decomposition, or pyrolysis, using a feedstock gas reactor. The feedstock gas reactor includes a reaction chamber connected, for example by one or more fluid flow passageways, to a heating chamber. A feedstock gas is caused to flow into the reaction chamber. For example, a controller comprising circuitry, such as a computer processor, may be configured to control suitable valving and one or more compressors to allow the feedstock to flow under pressure into the reaction chamber. Once the feedstock gas has filled the reaction chamber, the valving may be closed to seal the feedstock gas within the reaction chamber.

[0023] In addition, an “energy fluid” is caused to flow into the heating chamber. The loading of the heating chamber with the energy fluid may occur simultaneously to the loading of the reaction chamber with the feedstock gas, or at a different time. The energy fluid is then heated in the heating chamber without combusting the energy fluid. For example, the energy fluid may be heated in the absence of any oxidant. For instance, the energy fluid may be heated using a plasma generated by passing an electrical current through a suitable gas which may or may not be the energy fluid itself.

[0024] If the energy fluid is a gas, the pressure of the energy fluid in the heating chamber will increase rapidly as heat is added due to P1/T1 = P2/T2 (from the ideal gas law and assuming a constant-volume system), wherein Pi and T1 are the initial pressure and temperature of the energy fluid and P2 and T2 are the final pressure and temperature of the energy fluid. If the energy fluid is a liquid, the pressure of the energy fluid in the heating chamber will increase rapidly as heat is added, due to the phase change of the fluid from liquid to gas. According to some embodiments, the energy fluid may be inert (such as argon) so that it does not contribute chemical species during decomposition of the feedstock gas. Alternatively, the energy fluid may include one or more products of the decomposition reaction. For instance, with natural gas as the feedstock gas, the energy fluid may comprise hydrogen. The hydrogen may be hydrogen that has been formed as a result of decomposition of the feedstock gas in a prior reaction cycle, and that has been being recycled to the heating chamber.

[0025] The rapid heating of the energy fluid causes the pressure of the energy fluid to increase above that of the feedstock gas in the reaction chamber, following which the heated energy fluid flows into the reaction chamber and mixes with the feedstock gas. As a result of the mixing of the heated energy fluid with the feedstock gas, the feedstock gas is decomposed in the reaction chamber, and one or more reaction products are produced. In particular, once the temperature and pressure critical for decomposition of the feedstock gas are reached, the feedstock gas decomposes into its constituent components. The products of the decomposition (i.e., the reaction products) are then flowed out of the reaction chamber, for example by controlling an outlet valve. [0026] Once the reaction chamber is evacuated of reaction products, the reaction chamber may be re-loaded with feedstock, the heating chamber may be re-loaded with energy fluid, and the cycle may be repeated.

[0027] Referring to FIG. 1 , there is shown a system 100 for decomposing a feedstock gas (or simply “feedstock”) using an energy fluid, according to an embodiment of the disclosure.

[0028] A feedstock 12 is introduced into a reaction chamber 10. Feedstock 12 may be preheated - pre-heating of feedstock 12 may lower the energy requirements for triggering pyrolysis of feedstock 12. The flow of feedstock 12 into reaction chamber 10 may be controlled by an inlet valve 14 under control of a controller, as described above. As feedstock 12 is being loaded into reaction chamber 10, an energy gas 23 is introduced into a heating chamber 20. The flow of energy gas 23 into heating chamber 20 may be controlled by an inlet valve 24 under control of a controller, as described above. The pressures of feedstock 12 and energy gas 23 in reaction chamber 10 and heating chamber 20 are approximately equal to assist in reducing the transfer of either fluid between reaction chamber 10 and heating chamber 20. All valves are then closed to form a closed volume consisting of the combined volumes of reaction chamber 10, heating chamber 20, and a passageway 22 connecting reaction chamber 10 to heating chamber 20. According to some embodiments, reaction chamber 10 and heating chamber 20 may be connected using multiple passageways. According to some embodiments, passageway 22 may initially be sealed (for example, using a valve or a burst disk) such that the closed volume consists of the volume of heating chamber 20. In such a case, passageway 22 becomes open only once the pressure within heating chamber 20 is sufficient to rupture the burst disk, or when the valve is opened.

[0029] A heat source is then activated to rapidly heat energy gas 23 and cause its temperature and pressure to rise. In the embodiment of FIG. 1 , the heat source comprises a plasma 26 created by opposing cathode and anode electrodes 34 and 36 within heating chamber 20, and initiated by the closing of a switch 32 in an electrical circuit. Plasma 26 is created using electricity 30, and this electricity may be produced from renewable sources such as wind and/or solar energy. This may reduce the overall greenhouse gas emission profile of the reactor.

[0030] Instead of using electrical-based or plasma-based heating, other means of heating energy gas 23 may be used. For example, resistance, microwave, induction, photon, and/or infrared heating can also be used. According to some embodiments, a fuel may be heated by combustion, with the energy of that combustion being used to heat energy gas 23. [0031] Due to the increase in pressure of energy gas 23, the hot energy gas 23 flows through fluid passageway 22 and into reaction chamber 10 where the hot energy gas 23 mixes with feedstock 12, raising its temperature and pressure. This creates the conditions required for pyrolysis, breaking down feedstock gas 12 into (in the case of a hydrocarbon feedstock) hydrogen gas and carbon. An outlet product valve 16 is then opened to expel the reaction products 18 from reaction chamber 10. The cycle may then be repeated.

[0032] Downstream of reaction chamber 10, produced carbon may be separated from reaction products 18, and any desired product gases (such as hydrogen) may be separated from the other reaction products. These other reaction products may be returned to reaction chamber 10. If energy gas 23 is inert or otherwise non-reactive with feedstock 12, then energy gas 23 is separated from the other reaction products and may be recycled back to heating chamber 20. If the desired product gas includes energy gas 23, then a portion of this product gas may be recycled back to heating chamber 20.

[0033] As a specific example, using natural gas as the feedstock and hydrogen as the energy fluid, the natural gas is loaded into reaction chamber 10 and the hydrogen is loaded into heating chamber 20. All valves are then closed. Switch 32 is then closed to create a plasma arc 26 in heating chamber 20, rapidly heating the hydrogen gas and causing its pressure to rise. The difference in pressure between the hydrogen gas in heating chamber 20 and the natural gas in reaction chamber 10 causes the heated hydrogen to flow into reaction chamber 10 via fluid passageway 22, mix with the natural gas, and transfer energy to the natural gas. This creates the conditions whereby the natural gas dissociates into hydrogen and solid carbon. Outlet valve 16 of reaction chamber 10 is then opened and the reaction products are released from reaction chamber 10. The cycle is then repeated.

[0034] The reaction products leaving reaction chamber 10 flow to a carbon separator (not shown) wherein carbon is removed from the product gas stream. The product gas stream then flows to a hydrogen separator (not shown) wherein hydrogen gas is removed from the product gas stream. A portion of this stream is directed back to heating chamber 20, whereas the rest of the stream is sent elsewhere for end use. Other product gases output from the hydrogen separator, comprising unreacted methane and other gases, are returned to reaction chamber 10.

[0035] T urning to FIG. 2, there is shown a flow diagram of a method of decomposing a feedstock using an energy fluid, according to an embodiment of the disclosure. [0036] At block 205, the reaction chamber is loaded with the feedstock.

[0037] At block 210, the heating chamber is loaded with the energy fluid. The operations of blocks 205 and 210 may occur at the same or at different times.

[0038] At block 215, the energy fluid in the heating chamber is heated in a constant-volume process.

[0039] At block 220, the heated energy fluid flows from the heating chamber to the reaction chamber, and mixes with the feedstock. Heat from the energy fluid transfers to the feedstock and triggers decomposition of the feedstock, generating one or more reaction products.

[0040] At block 225, the one or more reaction products are extracted from the reaction chamber, and a portion of the one or more reaction products may be recycled to the heating chamber as energy fluid to be used in a subsequent reaction cycle.

[0041] The word “a” or “an” when used in conjunction with the term “comprising” or “including” in the claims and/or the specification 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 content clearly dictates otherwise. Similarly, the word “another” may mean at least a second or more unless the content clearly dictates otherwise.

[0042] The terms “coupled”, “coupling” or “connected” as used herein can have several different meanings depending on the context in which these terms are used. For example, as used herein, the terms coupled, coupling, or connected can indicate that two elements or devices are directly connected to one another or connected to one another through one or more intermediate elements or devices via a mechanical element depending on the particular context. The term “and/or” herein when used in association with a list of items means any one or more of the items comprising that list.

[0043] As used herein, a reference to “about” or “approximately” a number or to being “substantially” equal to a number means being within +/- 10% of that number.

[0044] Use of language such as “at least one of X, Y, and Z,” “at least one of X, Y, or Z,” “at least one or more of X, Y, and Z,” “at least one or more of X, Y, and/or Z,” or “at least one of X, Y, and/or Z,” is intended to be inclusive of both a single item (e.g., just X, or just Y, or just Z) and multiple items (e.g., {X and Y}, {X and Z}, {Y and Z}, or {X, Y, and Z}). The phrase “at least one of” and similar phrases are not intended to convey a requirement that each possible item must be present, although each possible item may be present. [0045] While the disclosure has been described in connection with specific embodiments, it is to be understood that the disclosure is not limited to these embodiments, and that alterations, modifications, and variations of these embodiments may be carried out by the skilled person without departing from the scope of the disclosure.

[0046] It is furthermore contemplated that any part of any aspect or embodiment discussed in this specification can be implemented or combined with any part of any other aspect or embodiment discussed in this specification.

Claims

1 . A method of decomposing a feedstock gas, comprising: introducing the feedstock gas into a reaction chamber; introducing an energy fluid into a heating chamber connected to the reaction chamber; and heating, in a constant-volume process, the energy fluid in the heating chamber without combusting the energy fluid, wherein, as a result of the heating, the heated energy fluid flows from the heating chamber to the reaction chamber and mixes with the feedstock gas, and wherein, as a result of the mixing, energy is transferred from the heated energy fluid to the feedstock gas and causes the feedstock gas to decompose.

2. The method of claim 1 , wherein the volume of the heating chamber defines a closed volume during the constant-volume process.

3. The method of claim 1 , wherein the combined volumes of the reaction chamber, the heating chamber, and any passageways connecting the reaction chamber to the heating chamber define a closed volume during the constant-volume process.

4. The method of any one of claims 1-3, wherein heating the energy fluid without combusting the energy fluid comprises heating the energy fluid in the absence of any oxidant.

5. The method of any one of claims 1-4, wherein heating the energy fluid comprises heating the energy fluid using plasma heating.

6. The method of any one of claims 1-5, wherein heating the energy fluid comprises heating the energy fluid using one or more: resistance heating; microwave heating; induction heating; photon heating; infrared heating; and heat generated from the combustion of a fuel.

7. The method of any one of claims 1-6, wherein: the feedstock gas comprises one or more first compounds; and the energy fluid comprises one or more second compounds selected so that, during decomposition of the feedstock gas, the one or more second compounds chemically react with the one or more first compounds to produce one or more reaction products.

8. The method of any one of claims 1-6, wherein the energy fluid is inert such that, during decomposition of the feedstock gas, the energy fluid does not chemically react with the feedstock gas.

9. The method of any one of claims 1-8, wherein: the decomposition of the feedstock gas produces one or more reaction products; and the method further comprises recycling at least some of the reaction products to the heating chamber for use as the energy fluid in a subsequent reaction cycle.

10. A system comprising: a feedstock gas reactor comprising: a reaction chamber; and a heating chamber connected to the reaction chamber; a heat source; valving and one or more compressors for allowing fluids to flow into and out of the reaction chamber and the heating chamber; and a controller comprising circuitry and configured to: control the valving and the one or more compressors to introduce a feedstock gas into the reaction chamber; control the valving and the one or more compressors to introduce an energy fluid into the heating chamber; control the heat source to heat, in a constant-volume process, the energy fluid in the heating chamber without combusting the energy fluid, wherein, as a result of the heating, the heated energy fluid flows from the heating chamber to the reaction chamber and mixes with the feedstock gas, and wherein, as a result of the mixing, energy is transferred from the heated energy fluid to the feedstock gas and causes the feedstock gas to decompose.

11. The system of claim 10, wherein the heat source comprises an electrical power supply and electrodes for generating an electrical current.

12. The system of claim 10 or 11, wherein the controller is further configured to control the valving and the one or more compressors to recycle at least some of one or more reaction products, produced as a result of the decomposition, to the heating chamber for use as the energy fluid in a subsequent reaction cycle.