Method and system for decomposing feedstock

Abstract

A method of decomposing a feedstock in a reaction chamber and a system. The volume of the reaction chamber is increased to draw the feedstock into the reaction chamber. An energy fluid is flowed into the reaction chamber to mix with the feedstock. As a result of the mixing of the energy fluid with the feedstock, energy is transferred from the energy fluid to the feedstock and decomposes the feedstock and forms one or more reaction products. The volume of the reaction chamber is reduced to expel one or more reaction products from the reaction chamber.

Description

Technical Field

[0001] The present disclosure relates to pyrolysis, and in particular to methods and systems for decomposing feedstocks. Background Art

[0002] Pyrolysis is a process that decomposes a feed gas (such as hydrocarbons) into its constituent elements (carbon and hydrogen in the case of hydrocarbons) in the absence of oxygen. The decomposition is triggered by raising the temperature of the feed gas sufficiently to the point where the chemical bonds of the elements of the feed gas break apart.

[0003] For example, such cracking can be achieved by thermally contacting the raw gas with a hot fluid. For example, combustion product gases formed by burning a combustible fuel can be mixed with the raw gas. At sufficiently high temperatures, the mixing of the hot fluid with the raw gas and the transfer of heat energy from the hot fluid to the raw gas are sufficient to cause the raw gas to split and decompose.

[0004] When operating a raw gas reactor, it is generally desirable that the raw materials loaded into the reaction chamber have plug flow. Plug flow can help to move the reaction product gases produced by the previous reaction cycle out of the reaction chamber. Plug flow can also help to minimize mixing between the raw materials and the reaction products from the previous reaction cycle.

[0005] However, achieving such plug flow is difficult and usually requires the use of a flow straightener in the reaction chamber. Therefore, the flow straightener must be able to withstand the high temperatures generated in the reaction chamber and is easily blocked by carbon due to its small flow passages. Summary of the invention

[0006] According to a first aspect of the present disclosure, a method for decomposing a raw material in a reaction chamber is provided, comprising: increasing the volume of the reaction chamber to draw the raw material into the reaction chamber; allowing an energy fluid to flow into the reaction chamber to mix with the raw material, wherein, due to the mixing of the energy fluid and the raw material, energy is transferred from the energy fluid to the raw material and causes the raw material to decompose and form one or more reaction products; and reducing the volume of the reaction chamber to discharge the one or more reaction products from the reaction chamber.

[0007] Drawing feedstock into the reaction chamber may include drawing feedstock into the reaction chamber via one or more feedstock inlets. Expelling reaction products from the reaction chamber may include withdrawing reaction products from the reaction chamber via one or more product outlets.

[0008] The one or more feed inlets and the one or more product outlets may be located at the same end of the reaction chamber.

[0009] Flowing the energy fluid into the reaction chamber may include: combusting the combustible mixture in a combustion chamber connected to the reaction chamber to form one or more combustion products; and flowing the one or more combustion products into the reaction chamber.

[0010] Combusting the combustible mixture may include: flowing one or more combustible gases into the combustion chamber through one or more combustion inlets to form the combustible mixture; and combusting the combustible mixture in the combustion chamber.

[0011] Flowing the one or more combustible gases into the combustion chamber may include increasing the volume of the reaction chamber to draw the one or more combustible gases into the combustion chamber via the one or more combustion inlets.

[0012] Reducing the volume of the reaction chamber may include: closing one or more combustion inlets; and reducing the volume of the reaction chamber after closing the one or more combustion inlets.

[0013] Flowing one or more combustible gases into the combustion chamber may include flowing a fuel and an oxidant into the combustion chamber.

[0014] The oxidant may include air or pure oxygen.

[0015] The fuel may have the same composition as the feedstock.

[0016] Prior to flowing one or more combustible gases into the combustion chamber, the combustion chamber may contain gases from a previous reaction cycle. Flowing one or more combustible gases into the combustion chamber may include exhausting gases from a previous reaction cycle from the combustion chamber and allowing the gases from the previous reaction cycle to enter the reaction chamber as a result of the one or more combustible gases flowing into the combustion chamber.

[0017] Drawing the feedstock into the reaction chamber may include drawing the feedstock into the reaction chamber via one or more feedstock inlets. Reducing the volume of the reaction chamber may include: closing the one or more feedstock inlets; and reducing the volume of the reaction chamber after closing the one or more fuel inlets.

[0018] Reducing the volume of the reaction chamber may include: opening one or more product outlets; and after opening the one or more product outlets, reducing the volume of the reaction chamber.

[0019] The decomposition of the feedstock may be a constant volume process, wherein the volume of the reaction chamber remains constant.

[0020] The feedstock may comprise hydrocarbons.

[0021] According to another aspect of the present disclosure, a system is provided, the system comprising: a reaction chamber; a combustion chamber connected to the reaction chamber; one or more feedstock inlets for allowing feedstock to enter the reaction chamber; one or more combustion inlets for allowing one or more combustible gases to enter the combustion chamber; and one or more product outlets for allowing reaction products to leave the reaction chamber; a drive mechanism for controlling the volume of the reaction chamber; one or more igniters in the combustion chamber; and a controller, the controller comprising a circuit configured to: control the drive mechanism to increase the volume of the reaction chamber, thereby drawing feedstock into the reaction chamber via the one or more feedstock inlets and drawing one or more combustible gases into the combustion chamber via the one or more combustion inlets; close the one or more feedstock inlets and the one or more combustion inlets; control the one or more igniters to burn the one or more combustible gases to form one or more combustion products that flow into the reaction chamber and mix with the feedstock, wherein, due to the mixing of the one or more combustion products with the feedstock, energy is transferred from the one or more combustion products to the feedstock, and the feedstock is decomposed and forms one or more reaction products; and control the drive mechanism to reduce the volume of the reaction chamber, thereby discharging the one or more reaction products from the reaction chamber via the one or more product outlets.

[0022] The one or more feed inlets and the one or more product inlets may be at the same end of the reaction chamber.

[0023] The drive mechanism may include a piston.

[0024] The controller may be further configured to open the one or more combustion inlets when the drive mechanism reaches the combustion chamber as the volume of the reaction chamber increases.

[0025] This summary does not necessarily describe the entire scope of all aspects. Other aspects, features and advantages will be apparent to one of ordinary skill in the art after reviewing the following description of specific embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Embodiments of the present disclosure will now be described in detail with reference to the accompanying drawings, in which:

[0027] Figure 1 is a schematic diagram of a feedstock reactor according to one embodiment of the present disclosure;

[0028] Figure 2 According to one embodiment of the present disclosure, at the beginning of the loading phase Figure 1 Schematic diagram of a raw material reactor;

[0029] Figure 3 According to one embodiment of the present disclosure, during the loading phase Figure 1 Schematic diagram of a raw material reactor;

[0030] Figure 4 According to one embodiment of the present disclosure, during the combustion phase Figure 1 Schematic diagram of a raw material reactor;

[0031] Figure 5 According to one embodiment of the present disclosure, during the unloading phase Figure 1 A schematic diagram of a feedstock reactor; and

[0032] Figure 6 is a flow chart of a method of operating a feedstock reactor according to one embodiment of the present disclosure. DETAILED DESCRIPTION

[0033] The present disclosure seeks to provide new methods and systems for decomposing feedstock in a reaction chamber.While various embodiments of the present disclosure are described below, the present disclosure is not limited to these embodiments and variations of these embodiments are likely to fall within the scope of the present disclosure limited only by the appended claims.

[0034] Generally, according to embodiments of the present disclosure, a method for decomposing a raw material in a reaction chamber is described. The volume of the reaction chamber is increased to draw the raw material into the reaction chamber. An energy fluid is flowed into the reaction chamber to mix with the raw material. Due to the mixing of the energy fluid and the raw material, energy is transferred from the energy fluid to the raw material, and the raw material is decomposed and formed into one or more reaction products. The volume of the reaction chamber is then reduced to discharge the one or more reaction products from the reaction chamber. The energy fluid can be any fluid with sufficient thermal energy so that when in thermal contact with the raw material, the decomposition of the raw material is triggered.

[0035] According to some embodiments, the energy fluid may be formed by combusting a fuel-oxidant mixture. Combustion products produced by the combustion may constitute the energy fluid, and the combustion products may be contacted and mixed with the feedstock.

[0036] Go to Figure 1-5 , showing various operating stages of a feedstock reactor according to one embodiment of the present disclosure. Figure 1-5 In each of the feed reactors 100, the feed reactor 100 includes a reaction chamber 101. The reaction chamber 101 is connected to a feed inlet 104 for allowing a feed 111 to enter the reaction chamber 101 and a product outlet 105 for allowing a reaction product 112 to leave the reaction chamber 101. The feed inlet 104 and the product outlet 105 are both located at the same end of the feed reactor 100.

[0037] A pair of combustion chambers 102a and 102b are connected to the reaction chamber 101 via one or more channels 103a, 103b. According to other embodiments, more or fewer combustion chambers may be connected to the reaction chamber 101. Each combustion chamber 102a, 102b is connected to a combustion inlet 107a, 107b for allowing a combustible gas mixture to enter the combustion chamber. Each combustion chamber 102a, 102b also includes an igniter 108a, 108b for triggering the combustion of the combustible gas mixture. The reciprocating piston 106 is configured to alternately increase and decrease the effective volume of the reaction chamber 101.

[0038] According to some embodiments, the combustible gas mixture includes a mixture of a fuel (such as a hydrocarbon, such as methane) and an oxidant (such as pure oxygen or air). The fuel may have the same composition as the feedstock. The fuel and oxidant may be delivered to the premixed combustion chamber 102a, 102b, or alternatively, the fuel and oxidant may be delivered to the combustion chamber 102a, 102b separately via respective inlets, and may be mixed together in the combustion chamber 102a, 102b using any of a variety of suitable mixing strategies (e.g., by appropriate positioning of the fuel and oxidant inlets).

[0039] During the load sequence ( Figure 2 ), piston 106 is positioned so that the volume 113 of reaction chamber 101 is close to zero, product outlet 105 is closed, and feedstock inlet 104 is opened. Piston 106 is then moved to the right by a controller (not shown), thereby increasing the volume 113 of reaction chamber 101 and drawing feedstock gas 111 into reaction chamber 101. The feedstock may be preheated (e.g., by using a heat exchanger or some other heater) before entering reaction chamber 101. This may reduce the requirement for the combustion product temperature needed to trigger feedstock decomposition (described in further detail below).

[0040] Once the piston 106 reaches the combustion chambers 102a and 102b ( Figure 3 ), combustion inlets 107a and 107b are opened, allowing combustible gas to enter combustion chambers 102a and 102b. As combustible gas is drawn into combustion chambers 102a and 102b, combustion products and other gases from the previous reaction cycle are pushed out of combustion chambers 102a and 102b and enter reaction chamber 101 via passages 103a and 103b.

[0041] When the piston 106 reaches the far end of the reaction chamber 101 (i.e., Figure 4As shown, when the reaction chamber 101 is at the end opposite to the end where the feedstock inlet 104 and the product outlet 105 are located, the feedstock inlet 104 and the combustion inlets 107a and 107b are closed. The combustible gas in the combustion chambers 102a and 102b is then ignited by the igniters 108a and 108b. The resulting high temperature and high pressure combustion products then flow out of the combustion chambers 102a and 102b via the passages 103a and 103b and are injected into the reaction chamber 101, where the combustion products mix with the feedstock 111 and trigger the decomposition of the feedstock 111. Considering the sealed nature of the reaction chamber 101 and the combustion chambers 102a and 102b, the decomposition of the feedstock 111 is a constant volume process.

[0042] In particular, thermal energy is transferred from the combustion products to the feedstock 111. As the pressure within the reaction chamber 101 increases in response to the flow of hot, pressurized combustion products into the reaction chamber 101, energy is also transferred from the hot combustion products to the feedstock 111 through dynamic compression of the feedstock 111. Beyond a certain point, the temperature increase of the feedstock 111 is sufficient to drive decomposition or cracking of the feedstock 111. For example, in the case of methane, the decomposition takes the following form:

[0043] CH4+energy→C+2H2

[0044] Once the desired reaction is complete, the product outlet 105 is opened and the piston 106 is moved back to the left (i.e., toward the end of the reaction chamber 101 where the feed inlet 104 and the product outlet 105 are located, such as Figure 5 10). The reaction products 112 produced by the cleavage are pushed out of the reaction chamber 101 via the product outlet 105. The cycle can then be repeated.

[0045] According to some embodiments, a portion of the reaction products 112 can be recycled back to the reaction chamber 101 for future reaction cycles. In the case of methane cracking, the reaction products 112 can include one or more of hydrogen, nitrogen, and carbon, the undesirable products are primarily carbon dioxide, nitrogen, and water, and the recycled gas mixture primarily contains unreacted natural gas, hydrogen, nitrogen, and carbon monoxide.

[0046] Go to Figure 6 , a flow chart of a method 200 for decomposing a feedstock according to an embodiment of the present disclosure is shown. Figure 6 The method described in can be used, for example, with Figure 1-5 The raw material reactor shown in is used in combination.

[0047] At block 202, a product valve of a reaction chamber is closed. The product valve allows reaction products produced within the reaction chamber to flow out of the reaction chamber.

[0048] At block 204, a feedstock valve of the reaction chamber is opened. The feedstock valve allows feedstock to flow into the reaction chamber. According to some embodiments, the operations performed at block 204 may precede the operations performed at block 202, or alternatively, they may occur simultaneously.

[0049] At box 206, the volume of the reaction chamber is increased, for example, by retracting a piston or other drive mechanism. The increase in the volume of the reaction chamber produces a pressure differential, which draws the raw material into the reaction chamber via the opened raw material valve. During the piston retraction, the n combustion valve of the combustion chamber is opened. The combustion chamber is connected to the reaction chamber fluid. The combustion valve allows a mixture of combustible gas, such as air / pure oxygen and fuel (such as a gas with the same composition as the raw material (e.g., recycled raw material)) to flow into the combustion chamber. Once the combustion valve is opened, the pressure differential caused by the continuous retraction of the piston draws the combustible gas into the combustion chamber via the opened combustion valve. When the combustible gas is drawn into the combustion chamber, the combustion products and other gases from the previous reaction cycle are pushed out of the combustion chamber and enter the reaction chamber.

[0050] When the piston reaches the combustion chamber, the combustion valve can be opened. This can be advantageous because if the combustion valve is opened before the piston reaches the combustion chamber, combustion gases and / or combustion products from the previous reaction cycle can enter the combustion chamber and flow into the reaction chamber behind the piston (the pressure behind the piston is not necessarily the same as the pressure in front of the piston).

[0051] According to some embodiments, the burn valve may be opened simultaneously with the operations in block 202 and / or block 204, or even before these operations.

[0052] At block 208, the feed valve and the burn valve are closed.

[0053] At block 210, the combustible gas mixture in the combustion chamber is combusted, for example by triggering an igniter such as a spark plug. The combustion of the combustible gas mixture produces combustion products, which flow into the reaction chamber under pressure, mix with the feedstock, and decompose the feedstock and produce reaction products.

[0054] At block 212, the product valve is opened.

[0055] At block 214, the volume of the reaction chamber is reduced, for example by extending a piston. This creates a pressure differential that forces the reaction products to leave the reaction chamber through the open product valve.

[0056] The cycle may then be repeated by returning to block 202 .

[0057] In addition to eliminating the need for rectifier / plug flow characteristics, the reciprocating design described herein provides a number of additional benefits. For example, positioning the feedstock inlet and product outlet at the same end of the reactor can improve thermal performance by reducing parasitic heat losses. This can increase the effective temperature of the feedstock during the loading portion of the cycle, which is useful because it reduces the combustion product temperature requirements needed to trigger feedstock decomposition.

[0058] Additionally, the moving piston can scrape the walls of the reaction chamber and eliminate carbon fouling and buildup, which is a common problem in many cracking reactors.

[0059] In addition, the feedstock pressure at the inlet can be reduced relative to the pressure of the product gas. This can reduce or eliminate the need for a recycle compressor, which can significantly improve performance and reduce capital and operating costs.

[0060] The operation of the various valves of the reactor may be controlled by a suitable controller comprising electronic circuits, such as a microprocessor.

[0061] 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 content clearly dictates otherwise. Likewise, the word "another" may mean at least a second or more, unless the content clearly dictates otherwise.

[0062] As used herein, the terms "coupled," "coupling," or "connected" can have several different meanings, depending on the context in which the terms are used. For example, as used herein, the terms "coupled," "coupling," or "connected" can indicate that two elements or devices are connected to each other directly or via mechanical elements through one or more intermediate elements or devices, depending on the specific context. When used in association with a list of items, the term "and / or" herein refers to any one or more of the items in the list.

[0063] As used herein, reference to "about" or "approximately" a number or "substantially" equal to a number means within + / - 10% of that number.

[0064] Language using 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 include both single items (e.g., only X, or only Y, or only 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 every possible item must be present, although every possible item may be present.

[0065] 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 skilled artisans may perform alterations, modifications and variations of these embodiments without departing from the scope of the present disclosure.

[0066] It is further contemplated that any portion of any aspect or implementation discussed in this specification may be implemented or combined with any portion of any other aspect or implementation discussed in this specification.

Claims

1. A method for decomposing a raw material in a reaction chamber, comprising: increasing the volume of the reaction chamber to draw the feedstock into the reaction chamber; flowing an energy fluid into the reaction chamber to mix with the feedstock, wherein due to the mixing of the energy fluid and the feedstock, energy is transferred from the energy fluid to the feedstock and causes the feedstock to decompose and form one or more reaction products; as well as The volume of the reaction chamber is reduced to discharge the one or more reaction products from the reaction chamber.

2. The method according to claim 1, wherein: Drawing the feedstock into the reaction chamber comprises drawing the feedstock into the reaction chamber via one or more feedstock inlets; and Discharging the reaction products from the reaction chamber includes discharging the reaction products from the reaction chamber via one or more product outlets.

3. The method according to claim 2, wherein: The one or more feed inlets and the one or more product outlets are located at the same end of the reaction chamber.

4. The method according to any one of claims 1 to 3, wherein: Allowing the energy fluid to flow into the reaction chamber comprises: combusting the combustible mixture in a combustion chamber connected to the reaction chamber to form one or more combustion products; and The one or more combustion products are flowed into the reaction chamber.

5. The method according to claim 4, wherein: Combusting the combustible mixture comprises: flowing one or more combustible gases into the combustion chamber via one or more combustion inlets to form the combustible mixture; and The combustible mixture is combusted in the combustion chamber.

6. The method according to claim 5, wherein: Flowing the one or more combustible gases into the combustion chamber includes increasing the volume of the reaction chamber to draw the one or more combustible gases into the combustion chamber through the one or more combustion inlets.

7. The method according to claim 6, wherein: Reducing the volume of the reaction chamber includes: closing the one or more combustion inlets; and After closing the one or more combustion inlets, the volume of the reaction chamber is reduced.

8. The method according to any one of claims 5 to 7, wherein: Flowing the one or more combustible gases into the combustion chamber comprises: Fuel and oxidant are flowed into the combustion chamber.

9. The method according to claim 8, wherein: The oxidant includes air or pure oxygen.

10. The method according to claim 8 or 9, wherein: The fuel has the same composition as the feedstock.

11. The method according to any one of claims 5 to 10, wherein: Prior to flowing the one or more combustible gases into the combustion chamber, the combustion chamber contains gases from a previous reaction cycle; and Flowing the one or more combustible gases into the combustion chamber includes exhausting gases from the previous reaction cycle from the combustion chamber and allowing gases from the previous reaction cycle to enter the reaction chamber as the one or more combustible gases flow into the combustion chamber.

12. The method according to any one of claims 1 to 11, wherein: Drawing the feedstock into the reaction chamber comprises drawing the feedstock into the reaction chamber via one or more feedstock inlets; as well as Reducing the volume of the reaction chamber includes: closing the one or more feedstock inlets; as well as After closing the one or more feedstock inlets, the volume of the reaction chamber is reduced.

13. The method according to claim 12, wherein: Reducing the volume of the reaction chamber includes: opening the one or more product outlets; and After opening the one or more product outlets, the volume of the reaction chamber is reduced.

14. The method according to any one of claims 1 to 13, wherein: The decomposition of the feedstock is a constant volume process, wherein the volume of the reaction chamber remains constant.

15. The method according to any one of claims 1 to 14, wherein: The feedstock comprises hydrocarbons.

16. A system comprising: Reaction chamber; a combustion chamber connected to the reaction chamber; one or more feedstock inlets for allowing feedstock to enter the reaction chamber; one or more combustion inlets for admitting one or more combustible gases into the combustion chamber; and one or more product outlets for allowing reaction products to exit the reaction chamber; A driving mechanism for controlling the volume of the reaction chamber; one or more igniters in said combustion chamber; and A controller, the controller comprising circuitry configured to: controlling the drive mechanism to increase the volume of the reaction chamber, thereby drawing the feedstock into the reaction chamber via the one or more feedstock inlets and drawing the one or more combustible gases into the combustion chamber via the one or more combustion inlets; closing the one or more feedstock inlets and the one or more combustion inlets; controlling the one or more igniters to combust the one or more combustible gases to form one or more combustion products that flow into the reaction chamber and mix with the feedstock, wherein due to the mixing of the one or more combustion products with the feedstock, energy is transferred from the one or more combustion products to the feedstock and causes the feedstock to decompose and form one or more reaction products; as well as The drive mechanism is controlled to reduce the volume of the reaction chamber, thereby discharging the one or more reaction products from the reaction chamber via the one or more product outlets.

17. The system of claim 16, wherein: The one or more feed inlets and the one or more product inlets are located at the same end of the reaction chamber.

18. The system according to claim 16 or 17, wherein: The drive mechanism includes a piston.

19. The system according to any one of claims 16 to 18, wherein: The controller is further configured to open the one or more combustion inlets when the drive mechanism reaches the combustion chamber as the volume of the reaction chamber increases.

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