Multitubular reactor system and process for nonoxidative conversion of methane

Abstract

The present disclosure relates to a process for converting C1-C3 alkanes, such as natural gas, into liquid C2-C 10 The present invention relates to a system and method for efficiently converting C1-C3 alkanes into products and hydrogen. Generally, the process includes flowing C1-C3 alkanes through a plurality of tubes in a vessel, the tubes including a plurality of tubes configured to flow the C1-C3 alkanes through a plurality of tubes in a vessel, the plurality of ... 10 The C1-C3 alkanes are heated under appropriate conditions to produce liquid C2-C3 alkanes, which are then converted into hydrogen and the resulting product. 10 Advantageously, the C1-C3 alkanes are heated by burning a fuel outside the tubes in a fuel combustion nozzle configured to transfer heat from the combustion through the tubes.

Description

[Technical field]

[0001] The present disclosure relates to converting C1-C3 alkanes into liquid C2-C 10 The present invention relates to a system and method for converting hydrogen into products. [Background technology]

[0002] Hydrogen is one of the more important options for the clean energy future. In addition, higher molecular weight hydrocarbons such as olefins and aromatics are often desired as value-added chemicals. In the past, methane has been used to produce such value-added chemicals, but the process is typically not cost-effective. What is needed is a solution to produce hydrogen and value-added chemicals in a cost-effective manner. It would be even more advantageous if such a solution were not energy-intensive. Summary of the Invention

[0003] Advantageously, the present application relates to new systems and methods for advantageously producing hydrogen and value-added chemicals in a cost-effective manner and without intensive energy consumption.

[0004] In one embodiment, the present application provides a method for preparing a C1-C3 alkane from a liquid C2-C 10 The process includes flowing C1-C3 alkanes through a plurality of tubes in a vessel, the tubes including a plurality of tubes configured to flow the C1-C3 alkanes through a plurality of tubes configured to flow the C1-C3 alkanes through a plurality of tubes in a vessel, the plurality of tubes including a plurality of tubes configured to flow the C1-C3 alkanes through a plurality of tubes configured to flow the C2 ... configured to flow the C2-C3 alkanes through a plurality of tubes configured to flow the C2-C3 alkanes through a plurality of 10 The C1-C3 alkanes are heated under appropriate conditions to produce liquid C2-C3 alkanes, which are then converted into hydrogen and the resulting product. 10 The C1-C3 alkanes are heated by burning a fuel outside the tubes in a fuel combustion nozzle configured to transfer heat from the combustion through the tubes to produce products and hydrogen.

[0005] In another embodiment, the present application provides a method for converting natural gas into liquid C2-C4 containing ethylene, benzene, naphthalene, or mixtures thereof. 10The process includes flowing natural gas through a plurality of tubes in a vessel, the tubes including a C2-C liquid, which may include ethylene, benzene, naphthalene, or a mixture thereof, into a product, hydrogen, and the like. 10 The natural gas is heated at a temperature of from about 500° C., or from about 700° C., to about 1000° C., or to about 1200° C., and at a pressure of from about 1 atmosphere, to about 3 atmospheres, to about 5 atmospheres, to about 10 atmospheres, or to about 20 atmospheres, to produce liquid C2-C4 containing ethylene, benzene, naphthalene, or mixtures thereof. 10 Products and hydrogen are produced. The natural gas is heated by burning fuel outside the tubes in a fuel combustion nozzle configured to transfer heat from the combustion through the tubes. Additionally or alternatively, electrical or other heating may be used in conjunction with or in place of the burning fuel.

[0006] In another embodiment, the present application relates to a reactor for converting alkanes to liquid hydrocarbons and hydrogen. The reactor comprises a vessel and a plurality of tubes within the vessel, the tubes configured to house a catalyst. The vessel is configured to combust a fuel outside of the plurality of tubes. The vessel is further configured to transfer heat from the burning fuel to the catalyst housed within the plurality of tubes.

[0007] These and other objects, features, and advantages of the exemplary embodiments of the present disclosure will become apparent from a reading of the following detailed description of the exemplary embodiments of the present disclosure, taken in conjunction with the appended claims.

[0008] The various embodiments of the present disclosure, together with further objects and advantages, may best be understood by referring to the following description taken in conjunction with the accompanying drawings, in which: [Brief description of the drawings]

[0009] [Figure 1] 1 shows the reaction temperature, pressure, and equilibrium conversion for the reaction of methane to benzene.

[0010] [Diagram 2] A typical multi-tube reactor equipped with a top-fired heater is shown. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] The following description of the embodiments provides a non-limiting representative example that refers to numbers to specifically describe the features and teachings of different aspects of the present invention. It should be recognized from the description of the embodiments that the described embodiments can be implemented separately or in combination with other embodiments. Those skilled in the art who review the description of the embodiments should be able to learn and understand the described different aspects of the present invention. The description of the embodiments should facilitate understanding of the present invention to the extent that other embodiments (embodiments not specifically covered but within the knowledge of those skilled in the art who read the description of the embodiments) are understood to be consistent with the application of the present invention.

[0012] <General process> This application relates to the conversion of C1-C3 alkanes into liquid C2-C 10 The process generally involves first flowing C1-C3 alkanes through a plurality of tubes within a vessel. The tubes typically contain liquid C2-C3 alkanes, which are then mixed with liquid C3-C4 alkanes and hydrogen. 10 The reactor contains a catalyst for converting the C1-C3 alkanes into products and hydrogen. The C1-C3 alkanes are not particularly limited and may include, for example, natural gas, methane, ethane, propane, or mixtures thereof. As used herein, natural gas includes methane and potentially higher alkanes, carbon dioxide, nitrogen or other gases, and / or sulfurized compounds such as hydrogen sulfide, and mixtures thereof. The products produced are typically liquid C2-C3 alkanes. 10 Includes products and hydrogen. Liquid C2-C 10 The product is not particularly limited and may be saturated, unsaturated, aromatic, or a mixture of such compounds. In some embodiments, Liquid C2-C 10The products may include ethylene, benzene, naphthalene, and various mixtures depending on the desired products and the reaction used.

[0013] C1-C3 alkanes are typically heated under suitable conditions in the presence of a catalyst to produce liquid C2-C 10 The reaction produces products and hydrogen. Suitable conditions may vary depending on the reactants, the desired products, the catalyst, and the equipment used. Typically, liquid C2-C4, which may include ethylene, benzene, naphthalene, or mixtures thereof, is used. 10 Temperatures from about 500° C., or from about 700° C., to about 1000° C., or to about 1200° C., and pressures from about 1 atmosphere to about 3 atmospheres, or to about 5 atmospheres, or to about 10 atmospheres, or to about 20 atmospheres may be used to produce products and hydrogen. In some embodiments, the C1-C3 alkanes are heated by burning a fuel outside the tubes in a fuel combustion nozzle configured to transfer heat from the combustion through the tubes. As described below, the hydrogen produced may be used as a fuel in the fuel combustion nozzle outside the tubes.

[0014] <Catalyst> The composition, morphology, size, shape, and properties of the catalyst can vary depending on parameters such as reactants, reactor type, tube size and shape, reaction conditions, and / or desired products. In some embodiments, the catalyst comprises a substantially cylindrical pellet. The catalyst pellet may include one or more holes extending through the length of the pellet, may have dome-shaped ends, and / or may include multiple grooves on the pellet surface. Suitable catalyst pellets are described, for example, in U.S. Publication US2021 / 0115341 to Sampath, published April 22, 2021, and incorporated herein by reference.

[0015] In some embodiments, the aspect ratio of the catalyst pellets (ratio of height to diameter or cross-sectional length) may be at least 0.3, or at least 0.5 to about 3, or to about 2. In some embodiments, the catalyst may include catalyst pellets with diameters of about 0.5 inches to about 1.0 inches, or to about 2.0 inches. In some embodiments, the catalyst pellets are substantially cylindrical, and at least a portion of the pellets include one or more holes that run through the length of the pellet. Holes through the catalyst pellets increase the external surface area and therefore generally reduce the characteristic length of the catalyst pellet to ensure adequate mass transfer rates. It may be desirable for the characteristic length, defined as the pellet volume divided by the external surface area, to be less than 0.3 cm, or less than 0.2 cm, or less than 0.15 cm. Proper porosity and pore structure can reduce the effective diffusivity of light hydrocarbons to 5×10 -3 ~2×10 -2 cm 2 / s and the catalyst effectiveness factor may range from 0.05, or from 0.1 to 0.5, or to 0.4.

[0016] The catalyst may, in some embodiments, include a washcoated honeycomb monolith catalyst or a metal monolith. The monolith may include ceramic, silica, quartz, glass, metal, silicon carbide, silicon nitride, boron nitride, metal oxides, or any combination thereof. Suitable metal oxides may include titania, iron oxide, zirconia, mixed metal oxides, or any combination thereof.

[0017] <Reactor Tubes> Like the catalyst, the tubes in the reactor may vary in shape, size, material, and / or properties depending on parameters such as the reactants, reactor type, reaction conditions, and / or desired products. The tubes may comprise ceramic, metal, or mixtures thereof. Suitable metals may include, for example, Alloy 800, Alloy 800 / HT, Alloy 309, other metallurgies suitable for high temperature service, or mixtures thereof.

[0018] In some embodiments, the tubes are configured to minimize or reduce pressure drop. For example, the tubes may be configured to provide a pressure drop of less than about 45 psig through the multiple tubes.

[0019] If desired, the tubes may include one or more metal inserts within the tubes to facilitate radial heat transfer within the tubes. The metal inserts may include screens, plates, or combinations thereof.

[0020] In this way, the effective radial thermal conductivity may be from about 5 to about 200 W / mK, and the temperature drop may be less than 50 to 200° C. The multiple tubes are arranged to have a heating load per tube of about 2 kW / m 2 Approximately 70kW / m from the tube 2 The size of the tubes may vary depending on the desired heat transfer and other properties of the system. In some embodiments, the diameter of the majority of the tubes in the vessel is from about 1 inch, or from about 2 inches to about 6 inches, or to about 7 inches. In some embodiments, the diameter of one or more of the tubes in the vessel is from about 1 inch, or from about 2 inches to about 6 inches, or to about 7 inches.

[0021] Typically, the reactor includes fuel combustion nozzles outside the tubes and along the length of the tubes to burn fuel outside the tubes. The fuel is not critical as long as it can adequately heat the tubes. In some embodiments, the fuel includes a hydrocarbon, hydrogen, or a mixture thereof. In some embodiments, the fuel may include hydrogen produced in the process. In some embodiments, at least a portion of the heat used to heat the C1-C3 alkanes in the tubes includes heat from exhaust gases generated during catalyst regeneration.

[0022] FIG. 1 shows the reaction temperature, pressure, and equilibrium conversion for the methane to benzene reaction according to the above embodiment.

[0023] Figure 2 shows a typical multi-tube reactor with a top-fired heater. In this embodiment, the feed enters the top of the tubes and passes over the catalyst inside the tubes. The tubes containing the catalyst and feed are heated using fuel that is burned next to or near the tubes. The products of the catalytic reaction exit the bottom of the reactor.

[0024] In the foregoing specification, various embodiments have been described with reference to the accompanying drawings. However, it will be apparent that various modifications and changes may be made and additional embodiments may be implemented without departing from the broader scope of the invention as set forth in the claims. The specification and drawings are therefore to be regarded in an illustrative rather than a restrictive sense.

Claims

1. C １ -C ３ Alkanes are ２ -C １０ and hydrogen, the process comprising: C through multiple tubes in the container １ -C ３ A process for flowing an alkane, １ -C ３ Alkanes are ２ -C １０ a catalyst for converting the product into hydrogen; C １ -C ３ The alkane is heated under appropriate conditions to form C ２ -C １０ producing products and hydrogen; Including, C １ -C ３ the alkane is heated by burning a fuel outside the tube in a fuel combustion nozzle configured to transfer heat from the combustion through the tube; The catalyst comprises cylindrical pellets; A process wherein at least some of the pellets contain one or more holes extending through the length of the pellet, are dome-shaped at the ends, contain a plurality of grooves on the pellet surface, and have an aspect ratio of at least 0.5 to about 2.

2. C １ -C ３ 10. The process of claim 1, wherein the alkane is derived from natural gas.

3. C ２ -C １０ 10. The process of claim 1, wherein the product comprises ethylene, benzene, naphthalene, or a mixture thereof.

4. The process of claim 1 , further comprising using one or more metal inserts within the plurality of tubes to facilitate radial heat transfer within the plurality of tubes.

5. The process of claim 1 , wherein the fuel comprises a hydrocarbon, hydrogen, or a mixture thereof.

6. 6. The process of claim 5, wherein at least a portion of the fuel comprises hydrogen produced in the process.

7. C １ -C ３ 10. The process of claim 1, wherein at least a portion of the heat used to heat the alkane comprises heat from exhaust gases generated during catalyst regeneration.

8. 10. The process of claim 1, wherein the pressure drop through the plurality of pipes is less than about 45 psig.

9. 10. The process of claim 1, wherein the diameter of the majority of the plurality of tubes in the vessel is from about 2 to about 6 inches.

10. 10. The process of claim 1, wherein the catalyst comprises catalyst pellets having a diameter of about 0.5 to about 1.0 inches.

11. 10. The process of claim 1, wherein the catalyst comprises a washcoated honeycomb monolith catalyst, the washcoated monolith catalyst comprising ceramic, silica, quartz, glass, metal, silicon carbide, silicon nitride, boron nitride, metal oxide, or any combination thereof.

12. 12. The process of claim 11, wherein the metal oxide comprises titania, iron oxide, zirconia, mixed metal oxide, or any combination thereof.

13. The process of claim 1 , wherein the catalyst comprises a metal monolith.

14. The process of claim 1, wherein the catalyst has a catalyst effectiveness factor of about 0.05 to about 0.

5.

15. Natural gas is mixed with a C 2000-4000-2000-4000-1 ... ２ -C １０ and hydrogen, the process comprising: flowing natural gas through a plurality of tubes in a vessel, the tubes including a C ２ -C １０ a catalyst for converting the product into hydrogen; Natural gas is heated at a temperature of about 700 to about 1000° C. and a pressure of about 1 to about 3 atmospheres to produce a C444 containing ethylene, benzene, naphthalene, or mixtures thereof. ２ -C １０ producing products and hydrogen; Including, the natural gas is heated by burning fuel outside the tubes in a fuel combustion nozzle configured to transfer heat from the combustion through the tubes; The catalyst comprises cylindrical pellets; A process wherein at least some of the pellets contain one or more holes extending through the length of the pellet, are dome-shaped at the ends, contain a plurality of grooves on the pellet surface, and have an aspect ratio of at least 0.5 to about 2.

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