Method for treating chemicals and reactor system utilizing tubular reactor

Abstract

A method for treating chemicals may include passing a hydrocarbon feed stream through an inlet of a tubular reactor positioned at least partially within a housing. The housing may include at least one heating element positioned between an inner surface of a sidewall of the housing and an outer surface of a wall of the tubular reactor. The method includes passing a first current through the wall of the tubular reactor to heat at least a portion of the wall of the tubular reactor, and passing a second current through the heating element to heat the heating element such that heat is transferred from the heating element to the wall of the tubular reactor. The process includes reacting at least a portion of the hydrocarbon feed stream within the tubular reactor to form a product stream, and passing the product stream through an outlet of the tubular reactor.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 432,168, filed on December 13, 2023, the entire disclosure of which is hereby incorporated by reference into this document. Technical Field

[0003]

[0013] Embodiments described herein generally relate to methods and systems for chemical processing. Background Art

[0004] Various chemicals can be produced by reacting a feed stream in a reactor system such as a tubular reactor to form a product stream. Some reactions that may occur in such a reactor system are endothermic, such as steam cracking and steam methane reforming. Heat can be supplied to the reactor system to drive such reactions.

[0005] Conventional heating methods rely on on-site combustion of fossil fuels to provide process heat, which may result in greenhouse gas emissions. For example, in some conventional reactor systems, numerous fuel gas burners are used to radiate heat from the combustion of fuel gas onto and through the tubular reactor walls to provide heat to the hydrocarbon feedstock and drive endothermic reactions to form desired products. The availability of renewable electricity creates opportunities to use renewable energy to provide heat without the need to burn fossil fuels, which results in lower emissions. Therefore, there is a need for improved systems and methods for using electricity to provide heat to reactor systems to process chemicals. Summary of the invention

[0006] Embodiments of the present disclosure relate to reactor systems that use electricity to provide heat to tubular reactors using both electric radiation heating technology and direct resistance heating technology. The reactor system may include one or more tubular reactors positioned in a housing. The electric heating element may be positioned in the housing to heat the tubular reactor by radiation heating. In addition, the wall of the tubular reactor itself may be heated by direct resistance heating. The combination of radiation heating from the electric heating element and direct resistance heating of the wall of the tubular reactor may provide the heat necessary to drive the endothermic reaction in the tubular reactor. In addition, without being constrained by any particular theory, the use of both radiation heating and resistance heating may allow the reactor system to have greater operational flexibility, reduce mechanical stress in the reactor system, allow the tubular reactor and the heating element to use less foreign materials, and allow the arrangement of the heating element and the tubular reactor in the reactor system to be more free. Therefore, the combination of direct resistance heating and radiation heating may be superior to conventional heating methods.

[0007] According to one or more embodiments of the present disclosure, a method for treating chemicals may include passing a hydrocarbon feed stream through an inlet of a tubular reactor. The tubular reactor may include an inlet, an outlet, and a wall extending at least from the inlet to the outlet. The tubular reactor may be at least partially positioned within a shell. The shell may include a first end, a second end, and at least one sidewall extending from the first end to the second end. The shell may include at least one heating element positioned between an inner surface of the sidewall of the shell and an outer surface of the wall of the tubular reactor. The method for treating chemicals may include passing a first current through at least a portion of the wall of the tubular reactor to heat at least a portion of the wall of the tubular reactor, and passing a second current through the heating element to heat at least a portion of the heating element, so that heat is transferred from the heating element to the wall of the tubular reactor. The method includes reacting at least a portion of the hydrocarbon feed stream within the tubular reactor to form a product stream, and passing the product stream through the outlet of the tubular reactor.

[0008] According to one or more additional embodiments of the present disclosure, a reactor system may include a tubular reactor, the tubular reactor including an inlet, an outlet and a wall extending at least from the inlet to the outlet. The wall of the tubular reactor may be connected to a first current source so that at least a portion of the tubular reactor can be operated to be heated when the first current passes through the tubular reactor. The reactor system may include a shell and at least one heating element, the shell including a first end, a second end and at least one sidewall extending from the first end to the second end, the at least one heating element being positioned between the inner surface of the sidewall of the shell and the outer surface of the wall of the tubular reactor. The heating element may be connected to a second current source. The tubular reactor may be at least partially positioned within the shell so that the tubular reactor can be operated to heat at least a portion of the tubular reactor when the second current passes through the heating element.

[0009] Additional features and advantages of the technology disclosed herein will be set forth in the detailed description that follows, and will in part be readily apparent to those skilled in the art from that description or recognized by practicing the technology as described herein, including the detailed description that follows, the claims, and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The following detailed description of certain embodiments of the present disclosure may be best understood when taken in conjunction with the following drawings, in which like reference numerals are used to indicate like structures and in which:

[0011] Figure 1 schematically depicts a reactor system including a tubular reactor according to one or more embodiments disclosed herein;

[0012] Figure 2schematically depicts a reactor system including a tubular reactor having a "U-shape" according to one or more embodiments described herein; and

[0013] Figure 3 A reactor system including a plurality of tubular reactors according to one or more embodiments described herein is schematically depicted. DETAILED DESCRIPTION

[0014] One or more non-limiting embodiments are described herein. As described herein, a method for treating a chemical may include passing a hydrocarbon feed stream through an inlet of a tubular reactor, reacting at least a portion of the hydrocarbon feed stream to form a product stream, and passing the product stream through the tubular reactor. The tubular reactor may be positioned within a housing, and the tubular reactor may be heated by radiant heating from a heating element positioned within the housing and by resistive heating of the wall of the tubular reactor. Without being bound by theory, the use of both radiant heating and resistive heating may allow the system to have greater operational flexibility, may reduce mechanical stress within the reactor system, may allow the tubular reactor and the heating element to use less foreign material, and may allow the arrangement of the heating element and the tubular reactor in the reactor system to be freer. These and other advantages are described in detail below.

[0015] Reference now Figure 1 , the hydrocarbon feed stream 102 can be passed to the tubular reactor 110. Figure 1 A cross section of a tubular reactor 110 is depicted, as will be appreciated by one skilled in the art. As described herein, a "reactor" refers to a container suitable for a given chemical reaction. A "tubular reactor" may refer to a reactor having a substantially tubular shape such that reactants and products are transferred from an inlet to an outlet of the reactor. Tubular reactors are described in more detail herein. Tubular reactor 110 may be part of a reactor system 100. Reactor system 100 may include one or more tubular reactors 110 and housing 120 as described in more detail herein.

[0016] In one or more embodiments, the tubular reactor 110 may include an inlet 111, an outlet 112, and a wall 113. The wall 113 may have a substantially circular cross-sectional shape. The wall may include an inner surface 115 and an outer surface 114. The wall 113 may extend from at least the inlet 111 of the tubular reactor 110 to the outlet 112. In one or more embodiments, the wall 113 may extend from the inlet 111 of the tubular reactor 110 to the outlet 112. In such embodiments, the inlet 111 and the outlet 112 may be positioned at opposite ends of the tubular reactor 110. In one or more embodiments not depicted, the wall 113 may extend beyond the inlet 111 or the outlet 112 or both. In such embodiments, the inlet 111 or the outlet 112 may not be positioned just at the end of the tubular reactor 110. However, the inlet 111 and the outlet 112 may be positioned close enough to the end of the tubular reactor 110 so as not to significantly impair the function of the tubular reactor 110. For example, the inlet 111 or the outlet 112 may be an opening in the wall 113 of the tubular reactor 110 near an end of the tubular reactor 110 , while the end of the tubular reactor 110 is closed.

[0017] In one or more embodiments, the tubular reactor 110 can have a substantially constant cross-sectional area from the inlet 111 of the tubular reactor 110 to the outlet 112 of the tubular reactor 110. As described herein, the cross-sectional area of ​​the tubular reactor 110 is perpendicular to the bulk flow of the hydrocarbon feed stream through the tubular reactor 110. As described herein, the cross-sectional area can be "substantially constant" when the cross-sectional area varies by less than 15%, less than 10%, less than 5%, or even less than 1% over the length of the tubular reactor 110 from the inlet 111 of the tubular reactor 110 to the outlet 112 of the tubular reactor 110. It should be noted that individual particles or molecules within a phase can move in a direction different from or even opposite to the bulk flow of the phase without affecting the direction of the bulk flow of the phase. For example, but not by way of limitation, individual hydrocarbon molecules within the hydrocarbon feed stream 102 can move in a direction different from the bulk flow of the hydrocarbon feed stream 102 without affecting the direction of the bulk flow of the hydrocarbon feed stream 102. In one or more embodiments, the overall flow of the hydrocarbon feed stream 102 through the tubular reactor 110 can be substantially plug flow from the inlet 111 of the tubular reactor 110 to the outlet 112 of the tubular reactor 110 .

[0018] The tubular reactor 110 may have any suitable cross-sectional shape. In one or more embodiments, the tubular reactor 110 may have a closed curved cross-sectional shape, a polygonal cross-sectional shape, or a combination thereof. For example, but not limited to, the tubular reactor 110 may have a cross-sectional shape such as a circle, an oval or an ellipse, a triangle, a rectangle, a pentagon, a hexagon, etc., or a combination of these shapes. In some embodiments, the tubular reactor 110 may have a substantially circular cross-sectional shape.

[0019] In one or more embodiments, the wall 113 of the tubular reactor 110 may include one or more bends between the inlet 111 of the tubular reactor 110 and the outlet 112 of the tubular reactor 110. For example, but not limitation, the wall 113 of the tubular reactor 110 may include a single bend and have a "U" shape, or the wall 113 of the tubular reactor 110 may include two or more bends and have an "S" shape, an "M" shape, a "W" shape, or other shapes. Now referring to Figure 2 In some embodiments, the wall 113 of the tubular reactor 110 includes a single bend and the tubular reactor 110 has a "U" shape.

[0020] Reference again Figure 1 , the wall 113 of the tubular reactor 110 can be straight, or substantially free of bends. In such embodiments, the wall 113 of the tubular reactor 110 can have a substantially hollow cylindrical shape. As described herein, when the cross section is a radial cross section relative to the hollow cylinder, the hollow cylindrical shape has a circular cross-sectional shape.

[0021] The tubular reactor 110 may be at least partially positioned within the housing 120. In some embodiments, the housing 120 may include a first end 121, a second end 122, and at least one sidewall 123 extending from the first end 121 to the second end 122. In one or more embodiments, the at least one sidewall 123 may have an inner surface 124. The inner surface 124 of the at least one sidewall 123 may be spaced apart from the outer surface 114 of the wall 113 of the tubular reactor 110. In other words, the inner surface 124 of the at least one sidewall 123 of the housing 120 may not be in direct contact with the outer surface 114 of the wall 113 of the tubular reactor 110. For example, conductive heating on the tubular reactor 110 by the heating element 130 may not be possible.

[0022] In one or more embodiments, the inlet 111 of the tubular reactor 110 may be positioned at the first end 121 of the housing 120, and the outlet 112 of the tubular reactor 110 may be positioned at the second end 122 of the housing. In such embodiments, the tubular reactor 110 may span the housing 120 from the first end 121 of the housing 120 to the second end 122 of the housing. In one or more embodiments, the wall 113 of the tubular reactor may include one or more bends, and the inlet 111 of the tubular reactor 110 and the outlet 112 of the tubular reactor may be positioned on the same end of the housing 120. For example, but not limitation, the inlet 111 of the tubular reactor 110 and the outlet 112 of the tubular reactor 110 may both be on the first end 121 of the housing 120 or on the second end 122 of the housing. Again referring to Figure 2 In the depicted embodiment, the inlet 111 and the outlet 112 of the tubular reactor 110 are both positioned at the first end 121 of the housing 120 .

[0023] Reference now Figure 3 , more than one tubular reactor 110 may be at least partially positioned within the housing 120. For example, in Figure 3 In the depicted embodiment, two tubular reactors 110a and 110b are positioned within the housing 120. In one or more embodiments, 2 to 50 tubular reactors 110 can be positioned within the housing 120. For example, but not limitation, the number of tubular reactors 110 positioned within the housing 120 can be 2 to 50, 10 to 50, 20 to 50, 30 to 50, 40 to 50, 2 to 40, 2 to 30, 2 to 20, 2 to 10, or any combination or subset of these endpoints. Generally, each tubular reactor 110 can be in direct line of sight with one or more heating elements 130.

[0024] In embodiments where more than one tubular reactor 110 is at least partially positioned within the housing 120, the reactor system 100 may further include an inlet manifold 211 to fluidly connect the inlet 111 of each tubular reactor 110. Figure 3 In the depicted embodiment, the inlet manifold 211 fluidly connects the inlet 111a of the tubular reactor 110a and the inlet 111b of the tubular reactor 110b, so that the hydrocarbon feed stream 102 can be delivered to both the inlet 111a and the inlet 111b. In addition, the reactor system 100 may include an outlet manifold 112 to fluidly connect the outlet 112 of each tubular reactor 110. Still referring to Figure 3, the outlet manifold 212 fluidly connects the outlet 112a of the tubular reactor 110a and the outlet 112b of the tubular reactor 110b so that the product stream 104 can pass through the tubular reactors 110a and 110b. It should be noted that the inlet manifold 211 and the outlet manifold 212 can be configured to accommodate any number of tubular reactors 110 positioned within the housing 120.

[0025] Reference again Figure 1 , the wall 113 of the tubular reactor 110 can be connected to a first current source 131. Passing the first current through the wall 113 of the tubular reactor 110 can heat the wall of the tubular reactor 110 by resistive heating. Without being bound by theory, resistive heating can occur by the "Joule effect". According to Joule's first law, the heating power generated by an electrical conductor is proportional to the product of its resistance (R) and the square of the current. Joule's first law is given in Equation 1, where P is power, I is current, and R is resistance.

[0026] P=I 2 R Equation 1.

[0027] In one or more embodiments, the wall 113 of the tubular reactor 110 can be connected to the first current source 131 near the inlet 111 of the tubular reactor 110 and the outlet 112 of the tubular reactor. For example, but not limiting, the first current source 131 can be connected to the wall 113 of the tubular reactor 110 at a point within 5%, 10%, 15%, or even 20% of the length of the wall 113 from the inlet 111 of the tubular reactor 110. Likewise, the first current source 131 can be connected to the wall 113 of the tubular reactor 110 at a point within 5%, 10%, 15%, or even 20% of the length of the wall 113 from the outlet 112 of the tubular reactor 110.

[0028] In one or more embodiments, the wall 113 of the tubular reactor 110 may be further connected to the first current source 131. For example, but not limitation, a third connection to the first current source 131 may be formed between the connections near the inlet 111 and the outlet 112. In one or more embodiments, the third connection between the first current source 131 and the wall 113 of the tubular reactor 110 may be made at a point within 5%, 10%, 15, or even 20% of the length of the wall 113 from the inlet 111 of the tubular reactor 110 to the midpoint of the wall 113 of the outlet 112. Without being bound by theory, when the third connection is made between the wall 113 of the tubular reactor 110 and the first current source 131, two heating zones may be formed in the wall 113 of the tubular reactor 110. It is contemplated that these heating zones may be independently controlled to form two heating zones within the tubular reactor 110. In one or more embodiments, additional connections can be made between the first current source 131 and the wall 113 of the tubular reactor 110 to form additional heating zones within the tubular reactor 110 .

[0029] In one or more embodiments, the wall 113 of the tubular reactor 110 can be conductive. In one or more embodiments, the wall 113 of the tubular reactor 110 can have a resistance of 1.0 μΩ·m to 4.0 μΩ·m at 900°C, 1.0 μΩ·m to 3.5 μΩ·m at 900°C, 1.0 μΩ·m to 3.0 μΩ·m at 900°C, 1.0 μΩ·m to 2.5 μΩ·m at 900°C, 1.0 μΩ·m to 2.0 μΩ·m at 900°C, 1.0 μΩ·m to 1.5 μΩ·m at 900°C, 1.5 μΩ·m to 4.0 μΩ·m at 900°C, 1.5 μΩ·m to 3.5 μΩ·m at 900°C, 1.5 μΩ·m to 3.0 μΩ·m at 900°C, 1.5 μΩ·m to 2.5 μΩ·m at 900°C. m, 1.5 μΩ·m to 2.0 μΩ·m at 900°C, 2.0 μΩ·m to 4.0 μΩ·m at 900°C, 2.0 μΩ·m to 3.5 μΩ·m at 900°C, 2.0 μΩ·m to 3.0 μΩ·m at 900°C, 2.0 μΩ·m to 2.5 μΩ·m at 900°C, 2.5 μΩ·m to 4.0 μΩ·m at 900°C, 2.5 μΩ·m to 3.5 μΩ·m at 900°C, 2.5 μΩ·m to 3.0 μΩ·m at 900°C, 3.0 μΩ·m to 4.0 μΩ·m at 900°C, 3.0 μΩ·m to 3.5 μΩ·m at 900°C, or 3.5 μΩ·m to 4.0 μΩ·m at 900°C. In one or more embodiments, the resistivity of the wall 113 of the tubular reactor 110 can vary over the length of the wall 113 .

[0030] In embodiments, tubular reactor 110 may have an inner diameter of 1 to 6 inches (in), 1 in to 5 in, 1 in to 4 in, 1 in to 3 in, 1 in to 2 in, 2 in to 6 in, 2 in to 5 in, 2 in to 4 in, 2 in to 3 in, 3 in to 6 in, 3 in to 5 in, 3 in to 4 in, 4 in to 6 in, 4 in to 5 in, or 5 in to 6 in. In one or more embodiments, the wall 113 of the tubular reactor can have a thickness of 0.1 in to 1.5 in, 0.1 in to 1.25 in, 0.1 in to 1.0 in, 0.1 in to 0.75 in, 0.1 in to 0.5 in, 0.1 in to 0.25 in, 0.25 in to 1.5 in, 0.25 in to 1.25 in, 0.25 in to 1.0 in, 0.25 in to 0.75 in, 0.25 in to 0.5 in, 0.5 in to 1.5 in, 0.5 in to 1.25 in, 0.5 in to 1.0 in, 0.5 in to 0.75 in, 0.75 in to 1.5 in, 0.75 in to 1.25 in, 0.75 in to 1.0 in, 1.0 in to 1.5 in, 1.0 in to 1.25 in, or 1.25 in to 1.5 in. In one or more embodiments, the wall 113 of the tubular reactor 110 can have a length of 10 meters (m) to 60m, 10m to 50m, 10m to 40m, 10m to 30m, 10m to 20m, 20m to 60m, 20m to 50m, 20m to 40m, 20m to 30m, 30m to 60m, 30m to 50m, 30m to 40m, 40m to 60m, 40m to 50m, or 50m to 60m. It is contemplated that the inner diameter, wall thickness, or both can vary over the length of the wall 113 of the tubular reactor 110.

[0031] The first current source 131 may be any suitable current source. The first current source 131 may be operable to provide alternating current or direct current to the wall 113 of the tubular reactor 110. For example, but not limitation, a suitable current source may be a commercially available power step-down transformer, such as a Thyristor type transformer from Fuji Electric.

[0032] In one or more embodiments, passing the first current through the wall 113 of the tubular reactor 110 can heat at least a portion of the wall 113 of the tubular reactor 110. In one or more embodiments, the wall 113 of the tubular reactor 110 can be heated to a temperature of 600° C. to 1100° C. For example, but not limitation, the wall 113 of the tubular reactor 110 can be heated to a temperature of 600° C. to 1100° C., 700° C. to 1100° C., 800° C. to 1100° C., 900° C. to 1100° C., 1000° C. to 1100° C., 600° C. to 1000° C., 600° C. to 900° C., 600° C. to 800° C., 600° C. to 700° C., or any combination or subset of these ranges.

[0033] Reference again Figure 1 , the housing 120 may include at least one heating element 130 positioned between the inner surface 124 of the sidewall 123 of the housing 120 and the outer surface 114 of the tubular reactor 110. The heating element 130 is operable to convert electricity into heat. Suitable heating elements may be described in International Publication No. WO 2020 / 002326 A1, the entire contents of which are incorporated herein by reference.

[0034] In one or more embodiments, the heating element 130 can convert electricity into heat by resistive heating, as described above. In one or more embodiments, the heating element 130 can include NiCr, SiC, MoSi 2 , graphite or FeCrAl, as the material through which the electric current passes to generate heat. In one or more embodiments, the heating element 130 may include silicon carbide (SiC). In one or more embodiments, the heating element 130 may take any suitable form. For example, but not limited to, the heating element 130 may include round wire, flat wire, stranded wire, strip, rod, hoop rod, etc. In one or more embodiments, the heating element 130 is resistant to exposure to air, hydrocarbons and steam. Without being bound by theory, the heating element is resistant to hydrocarbons and steam so that they are not damaged when hydrocarbons or steam are released due to a failure of a tubular reactor in a tubular reactor, which causes the release of reactants, products or both. However, it should be noted that suitable heating elements are not limited to those heating elements that are resistant to exposure to hydrocarbons or steam.

[0035] In one or more embodiments, the heating element 130 may have a resistance of 1.0 μΩ·m to 4.0 μΩ·m at 900°C, 1.0 μΩ·m to 3.5 μΩ·m at 900°C, 1.0 μΩ·m to 3.0 μΩ·m at 900°C, 1.0 μΩ·m to 2.5 μΩ·m at 900°C, 1.0 μΩ·m to 2.0 μΩ·m at 900°C, 1.0 μΩ·m to 1.5 μΩ·m at 900°C, 1.5 μΩ·m to 4.0 μΩ·m at 900°C, 1.5 μΩ·m to 3.5 μΩ·m at 900°C, 1.5 μΩ·m to 3.0 μΩ·m at 900°C, 1.5 μΩ·m to 2.5 μΩ·m at 900°C, The resistivity of the conductive material is 1.5 μΩ·m to 2.0 μΩ·m at 900°C, 2.0 μΩ·m to 4.0 μΩ·m at 900°C, 2.0 μΩ·m to 3.5 μΩ·m at 900°C, 2.0 μΩ·m to 3.0 μΩ·m at 900°C, 2.0 μΩ·m to 2.5 μΩ·m at 900°C, 2.5 μΩ·m to 4.0 μΩ·m at 900°C, 2.5 μΩ·m to 3.5 μΩ·m at 900°C, 2.5 μΩ·m to 3.0 μΩ·m at 900°C, 3.0 μΩ·m to 4.0 μΩ·m at 900°C, 3.0 μΩ·m to 3.5 μΩ·m at 900°C, or 3.5 μΩ·m to 4.0 μΩ·m at 900°C.

[0036] The housing 120 may include more than one heating element 130. It should be noted that the number of heating elements 130 positioned within the housing 120 may depend on the size of the housing 120, the number of tubular reactors 110 within the housing 120, the location of the tubular reactors 110 within the housing 120, the desired temperature of the tubular reactors 110, and the desired heat flux from the heating elements 130 to the tubular reactors 110. Without being bound by theory, when multiple heating elements 130 are positioned within the housing 120, the heating elements 130 may be controlled in groups or even individually. Individual control of the heating elements 130 in groups may allow for independent control of various heating zones within the housing 120.

[0037] In one or more embodiments, the heating element 130 is connected to a second current source 132. The second current source 132 can be any suitable current source. The second current source 132 is operable to supply alternating current or direct current to the heating element 130. By way of example and not limitation, a suitable current source can be a commercially available power step-down transformer, such as a Thyristor type transformer from Fuji Electric. In one or more embodiments, the power source 132 can include a silicon-controlled rectifier (SCR) that supplies discontinuous current to a resistive element or a variable voltage power source that provides a continuous voltage change in discrete steps. Conventional means can be used to measure the current from the latter. On the other hand, the current output from SCRs and semiconductor thyristor power sources is inherently discontinuous, and accurate measurement of the resulting discontinuous current can use techniques that account for the non-sinusoidal nature of the output waveform. In one or more embodiments, multiple heating elements 130 can be connected in series, in parallel, or a combination thereof, to customize the total heater circuit resistance, heater zone design, and voltage and current for the heating element (e.g., material resistivity, geometry, cross-sectional area, and element length) such that a desired heating power is achieved. It should be noted that the amount of current passing through the first current source 131 and the amount of current passing through the second current source 132 can be independently controlled such that the proportion of heat supplied to the system by resistive heating through the heating element 130 and through the wall 113 of the tubular reactor 110 can be independently controlled.

[0038] In one or more embodiments, passing a second current through the heating element 130 can heat at least a portion of the heating element 130. By resistive heating, the heating element 130 may be capable of reaching a temperature of at least 1000 °C, at least 1100 °C, at least 1200 °C, at least 1300 °C, at least 1400 °C, at least 1500 °C, at least 1600 °C, at least 1700 °C, at least 1800 °C, or even at least 1900 °C. By way of example and not limitation, the heating element 130 can have a temperature from 1000 °C to 1900 °C, from 1100 °C to 1900 °C, from 1200 °C to 1900 °C, from 1300 °C to 1900 °C, from 1400 °C to 1900 °C, from 1500 °C to 1900 °C, from 1600 °C to 1900 °C, from 1700 °C to 1900 °C, from 1800 °C to 1900 °C, from 1000 °C to 1800 °C, from 1000 °C to 1700 °C, from 1000 °C to 1600 °C, from 1000 °C to 1500 °C, from 1000 °C to 1400 °C, from 1000 °C to 1300 °C, from 1000 °C to 1200 °C, from 1000 °C to 1100 °C, or any combination or subset of these values.

[0039] In one or more embodiments, heat can be transferred from the heating element 130 to the wall 113 of the tubular reactor 110. Heat can be transferred by radiation, convection, or a combination of these. For example, but not limited to, heat can be radiated directly from the surface of the heating element 130 to the outer surface 114 of the wall 113 of the tubular reactor 110. In addition, heat can be radiated from the heating element 130 to the inner surface 124 of the shell 120. In turn, heat can be radiated from the inner surface 124 of the shell 120 to the outer surface 114 of the wall 113 of the tubular furnace 110. In addition, the gas contained in the shell can rise through the heating element 130 and descend through the tubular reactor 110, thereby heating the wall of the tubular reactor 110 by convection. In one or more embodiments, the outer surface 114 of the wall 113 of the tubular reactor 110 is spaced apart from the heating element 130. In such embodiments, heat is generally not transferred from the heating element 130 to the wall 113 of the tubular reactor 110 by conduction.

[0040] As described herein, the walls 113 of the tubular reactor 110 can be heated by resistive heating of the walls 113 of the tubular reactor 110 and by radiative heating from the heating element 130. In one or more embodiments, the heating element 130 can provide 10% to 50% of the heat to the walls 113 of the tubular reactor 110. For example, the heating element 130 can provide 10% to 50%, 20% to 50%, 30% to 50%, 40% to 50%, 10% to 40%, 10% to 30%, 10% to 20% of the heat to the walls 113 of the tubular reactor 110, or any combination or subset of these values.

[0041] In one or more embodiments, the resistive heating of the walls 113 of the tubular reactor 110 can provide 50% to 90% of the heat to the walls 113 of the tubular reactor 110. For example, the resistive heating of the walls 113 of the tubular reactor 110 can provide 50% to 90%, 60% to 90%, 70% to 90%, 80% to 90%, 50% to 80%, 50% to 70%, 50% to 60% of the heat to the walls 113 of the tubular reactor 110, or any combination or subset of these values.

[0042] Without being bound by theory, the use of resistive heating of the wall 113 of the tubular reactor 110 and radiative heating of the wall 113 from the heating element 130 may provide several advantages over systems that use only radiative heating of the wall 113 or only resistive heating of the wall 113. For example, the use of radiative heating of the wall 113 and resistive heating may provide a uniform temperature profile in the radial direction in the wall 113 of the tubular reactor 110. This may reduce material stresses within the wall 113 of the tubular reactor 110 when the reactor 110 is at operating temperature. Additionally, the uniform temperature profile may allow electrical current to pass more uniformly through the wall 113 of the tubular reactor 110. This may prevent the formation of hot spots within the wall 113 of the tubular reactor 110, which may result in uneven heating of hydrocarbons passing through the tubular reactor.

[0043] In addition, without being bound by theory, the use of radiation and resistance heating of the wall 113 of the tubular reactor 110 can allow the system to have greater operational flexibility, especially with respect to changing the heating mechanism during different stages of operation. For example, during the startup of the reactor, radiation heating can be used to bring the reactor tube to a temperature at which resistance heating is more efficient. This can reduce the amount of energy necessary to start the reactor system 100. During the steady-state operation of the reactor system 100, the resistance heating of the wall of the tubular reactor can be the main heat source, and radiation heating can be used to reduce the heat loss from the wall 113 of the tubular reactor. Radiative heating can also compensate for the heat loss from the sidewall 123. In addition, the use of both radiation heating and resistance heating allows the reactor to enter a "hot standby" operating mode, in which radiation heating is used to maintain the temperature of the reactor close to the operating temperature while stopping the resistance heating of the tube. This operating mode is useful in situations where the reaction is not currently occurring in the reactor but it is not desired to completely shut down the reactor system 100. Specifically, when a relatively short operational pause is desired, the hot standby mode can prevent the energy loss associated with the complete shutdown of the reactor system 100.

[0044] In addition, without being bound by theory, the use of both radiant heating and resistive heating of the wall 113 of the tubular reactor 110 can distribute the heating load across multiple heating elements. Specifically, the heating element 130 can provide radiant heating to the wall 113 of the tubular reactor 110, and the resistive heating of the wall 113 itself can provide heat to the wall 113 of the tubular reactor. Since neither radiant heating nor resistive heating provides all the heat to the reactor system 100, the reactor system 100 can be operated with a reduced number of heating elements 130 relative to conventional systems. In addition, a wider range of materials can be used for the heating element 130 and the wall 113 of the tubular reactor 110 because neither of the two heating mechanisms is responsible for providing all the heat to the reactor system 100. Therefore, less exotic materials can be suitable for the heating element 130 and the wall 113 of the tubular reactor 110. Less exotic materials can be suitable because the maximum system temperature can be less than the maximum system temperature of a conventional combustion ignition furnace, and having both radiant and resistive heating can provide a larger surface area to deliver the required heat flux, thereby reducing thermal stress on the heating element 130 and increasing material life. For example, but not limited to, less exotic materials for the heating element 130 may include nickel chromium (NiCr80 / 20), nickel chromium (NiCr 70 / 30), both of which are capable of operating at temperatures in excess of 1100°C, and ferritic iron-chromium-aluminum alloy (FeCrAl), which is capable of operating at an operating temperature of 1400°C and has good electrical resistance and very good oxidation resistance.

[0045] Additionally, without being bound by theory, the use of both radiant heating and resistive heating of the walls 113 of the tubular reactor 110 may allow for greater freedom in the arrangement of the tubular reactors 110 and the heating elements 130 within the housing 120. For example, and without limitation, the density of the tubular reactors 110 within the housing 120 may be increased relative to a reactor system that relies solely on radiant heating. This is possible because the heating elements 130 contribute only a portion of the heat to the reactor system 100, and the resistive heating of the walls 113 of the tubular reactor 110 themselves also contributes heat to the reactor system 100. When each tubular reactor 110 is able to provide a portion of the necessary heat through resistive heating, the system may be able to accommodate more tubular reactors 110. Thus, when both radiant and resistive heating are used, it is possible to increase the density of the tubular reactors 110 in the housing 120.

[0046] In addition, without being bound by theory, the use of both radiation heating and resistance heating of the wall 113 of the tubular reactor 110 can allow independent control of the heating mechanism. This can allow the previously described operational flexibility. In addition, independent control of the heating mechanism can allow multiple heating zones to be formed in the shell. Without being bound by theory, the use of multiple heating zones can allow for more stringent control of the temperature distribution in the shell. In addition, when multiple heating zones are designed to compensate for the loss of a heating zone in the event of a zone failure, the use of multiple heating zones can increase the overall reliability and operation of the system.

[0047] In one or more embodiments, the method for treating chemicals includes conveying a hydrocarbon feed stream 102 to a tubular reactor 110, reacting at least a portion of the hydrocarbon feed stream 102 within the tubular reactor 110 to form a product stream 104, and passing the product stream 104 through an outlet 112 of the tubular reactor 110. It should be noted that reacting the hydrocarbon feed stream 102 to form the product stream 104 may include performing any endothermic reaction. In some embodiments, the endothermic reaction may be a steam cracking reaction, a steam reforming reaction, or a hydrotreating reaction. However, it should be noted that the methods for treating chemicals described herein are not necessarily limited to these reactions.

[0048] According to one or more embodiments, the reaction can be a steam cracking reaction. However, the described embodiments are applicable to a wide range of chemical processes. As described herein, "steam cracking reaction" refers to the thermal cracking of hydrocarbons in the presence of steam to produce products such as hydrogen, olefins and aromatic hydrocarbons. Without being bound by theory, the pyrolysis reaction of hydrocarbons follows a free radical mechanism and requires high temperatures. Steam can act as a diluent to reduce the partial pressure of hydrocarbons, which can improve selectivity by promoting a higher yield of light olefins.

[0049] In one or more embodiments, the hydrocarbon feed stream 102 may include at least one of methane, ethane, propane, and butane. In some embodiments, the hydrocarbon feed stream 102 may include naphtha or vacuum gas oil. In some embodiments, the hydrocarbon feed stream 102 may include C 1 To C 5 Hydrocarbon, C 1 To C 20 Hydrocarbons or even C 1 To C 50 In some embodiments, the hydrocarbon feed stream 102 may also include water or steam (H 2 O), CO 2 ,CO,N 2 ,CO,CO 2 , H 2 or a combination thereof.

[0050] In one or more embodiments, the product stream 104 is composed of at least one of hydrogen, olefins, and aromatic hydrocarbons. The product stream 104 can include olefins such as ethylene, propylene, 1-butene, 2-butene, isobutylene, 1-pentene, 2-pentene, 2-methyl-1-butene, 3-methyl-1-butene, 2-methyl-2-butene, or combinations thereof. In one or more embodiments, the product stream can include C 2 To C 10 Olefins, C 2 To C 20 Olefins, or even C 2 To C 50 Olefins. In one or more embodiments, the product stream 104 can include aromatic hydrocarbons such as benzene and its derivatives. The product stream 104 can include benzene, toluene, ethylbenzene, o-xylene, p-xylene, m-xylene, mesitylene, durene, 2-phenylhexane, biphenyl, or combinations thereof.

[0051] In one or more embodiments, the product stream 104 can include greater than 20 wt%, greater than 25 wt%, greater than 30 wt%, greater than 35 wt%, or greater than 40 wt% olefins, aromatics, or combinations thereof. For example, but not limiting of, the product stream 104 can include 20 wt% to 100 wt%, 30 wt% to 100 wt%, 40 wt% to 100 wt%, 50 wt% to 100 wt%, 60 wt% to 100 wt%, 70 wt% to 100 wt%, 80 wt% to 100 wt%, 90 wt% to 100 wt%, 20 wt% to 90 wt%, 20 wt% to 80 wt%, 20 wt% to 70 wt%, 20 wt% to 60 wt%, 20 wt% to 50 wt%, 20 wt% to 40 wt%, 20 wt% to 30 wt%, or any combination or subset of these ranges of olefins, aromatics, or combinations thereof.

[0052] In one or more embodiments, the methods for treating chemicals described herein may further include preheating the hydrocarbon feed stream 102. Preheating the hydrocarbon feed stream 102 may occur before transferring the hydrocarbon feed stream 102 to the inlet 111 of the tubular reactor 110. In one or more embodiments, preheating the hydrocarbon feed stream 102 may include passing the hydrocarbon feed stream 102 through a heat exchanger 141. In one or more embodiments, the hydrocarbon feed stream 102 may pass through a plurality of heat exchangers in parallel, in series, or a combination of both. The heat exchanger 141 may be any suitable heat exchanger, including but not limited to a shell and tube heat exchanger. Preheating the hydrocarbon feed stream 102 may increase the temperature of the hydrocarbon feed stream 102 to a temperature of 300°C, 400°C, 500°C, or even 600°C. In one or more embodiments, the temperature of the hydrocarbon feed stream 102 leaving the heat exchanger 141 may be lower than the temperature of the wall 113 of the tubular reactor 110.

[0053] In one or more embodiments, the method for treating chemicals described herein may further include cooling the product stream 104 in the heat exchanger 142. The heat exchanger 142 may cool the product stream 104 to below the reaction temperature. Cooling the product stream 104 to below the reaction temperature may prevent further reaction or conversion of the product stream 104. In one or more embodiments, the heat exchanger 142 may cool the product stream 104 to a temperature below 1200°C, below 1000°C, below 800°C, below 600°C, or even below 500°C. In one or more embodiments, the heat exchanger 142 may include a quench exchanger or any other suitable heat exchanger. In some embodiments, the heat removed from the product stream 104 may be used to heat the hydrocarbon feed stream 102. In one or more embodiments, cooling the product stream 104 may be performed in multiple heat exchangers in parallel, in series, or a combination of both.

[0054] It should be noted that the method steps set forth herein should not be interpreted as requiring these steps to be performed in a particular order unless otherwise specified. For example, but not by way of limitation, it is contemplated that in the method for treating chemicals described herein, the method steps of passing a first current through at least a portion of the wall of a tubular reactor to heat at least a portion of the wall of the tubular reactor and passing a second current through a heating element to heat at least a portion of the heating element do not necessarily have to be performed in any particular order, and the claims recording these method steps should not be interpreted as requiring them to be performed in any particular order. It is contemplated that in one or more embodiments described herein, the method steps of passing a first current through at least a portion of the wall of a tubular reactor and passing a second current through a heating element may occur at any point in the method for treating chemicals described herein. Specifically, such method steps may occur before, during, and after passing a hydrocarbon feed stream through the inlet of a tubular reactor, before, during, and after reacting a hydrocarbon feed stream to form a product stream, and before, during, and after passing a product stream from a tubular reactor.

[0055] It should be noted that one or more of the appended claims utilize the term "wherein" as a transitional expression. For purposes of defining the present technology, it should be noted that this term is introduced in the claims as an open transitional phrase that is used to introduce a recitation of a series of features of a structure and should be interpreted in a manner similar to the more commonly used open-ended term "comprising."

[0056] It should be understood that where a first component is described as "comprising" a second component, it is contemplated that in some embodiments, the first component "consists of" or "consists essentially of" the second component. It should also be understood that where a first component is described as "comprising" a second component, it is contemplated that in some embodiments, the first component may contain at least 10%, at least 20%, at least 30%, at least 40%, at least 50%, at least 60%, at least 70%, at least 80%, at least 90%, at least 95%, or even at least 99% of the second component (wherein % may be wt % or mole %).

[0057] In addition, the term "consisting essentially of..." is used in the present disclosure to refer to a quantitative value that does not materially affect the basic and novel characteristics of the present disclosure. For example, a chemical composition consisting "essentially" of a specific chemical component or group of chemical components should be understood to mean that the composition contains at least about 99.5% of the specific chemical component or group of chemical components.

[0058] The subject matter of the present disclosure has been described in detail and by reference to specific embodiments. It should be understood that any detailed description of a component or feature of an embodiment does not necessarily imply that the component or feature is essential to the specific embodiment or any other embodiment. Further, it will be apparent to those skilled in the art that various modifications and changes may be made to the described embodiments without departing from the spirit and scope of the claimed subject matter.

Claims

1. A method for treating chemicals, the method comprising: include: A hydrocarbon feed stream is passed through the inlet of a tubular reactor wherein: The tubular reactor comprises the inlet, the outlet and a wall extending at least from the inlet to the outlet; The tubular reactor is at least partially positioned within the housing; The housing includes a first end, a second end, and at least one sidewall extending from the first end to the second end; and The housing includes at least one heating element positioned between an inner surface of the side wall of the housing and an outer surface of the wall of the tubular reactor; passing a first electrical current through at least a portion of the wall of the tubular reactor to heat at least a portion of the wall of the tubular reactor; passing a second current through the heating element to heat at least a portion of the heating element such that heat is transferred from the heating element to the wall of the tubular reactor; reacting at least a portion of the hydrocarbon feed stream within the tubular reactor to form a product stream; The product stream is passed through the outlet of the tubular reactor. 2 . The method of claim 1 , wherein the heating element is spaced apart from the outer surface of the wall of the tubular reactor.

3. A method according to claim 1 or claim 2, wherein the side wall of the housing is spaced apart from the outer surface of the wall of the tubular reactor.

4. The process according to any one of claims 1 to 3, wherein the cross-sectional area of ​​the tubular reactor perpendicular to the bulk flow of the hydrocarbon feed stream through the tubular reactor is substantially constant from the inlet of the tubular reactor to the outlet of the tubular reactor.

5. The process according to any one of claims 1 to 4, wherein 2 to 50 tubular reactors according to claim 1 are at least partially positioned within the housing.

6. The method of claim 5, wherein the tubular reactors are connected to an inlet manifold to fluidly connect the inlet of each tubular reactor, and the tubular reactors are connected to an outlet manifold to fluidly connect the outlet of each tubular reactor.

7. The method according to any one of claims 1 to 6, wherein the heating element comprises NiCr, SiC, MoSi 2 , graphite or FeCrAl.

8. The method of any one of claims 1 to 7, wherein the first current, the second current, or both comprise alternating current.

9. The method of any one of claims 1 to 7, wherein the first current, the second current, or both comprise direct current.

10. The process of any one of claims 1 to 9, wherein the hydrocarbon feed stream comprises one or more of ethane, propane, butane, naphtha, and vacuum gas oil.

11. The process of any one of claims 1 to 10, wherein reacting the hydrocarbon feed stream comprises steam cracking at least a portion of the hydrocarbon feed stream, and the product stream comprises one or more olefins.

12. A reactor system, the reactor system include: a tubular reactor comprising an inlet, an outlet, and a wall extending at least from the inlet to the outlet, wherein the wall of the tubular reactor is connected to a first electric current source such that at least a portion of the tubular reactor is operable to be heated when the first electric current passes through the tubular reactor; and A housing, the housing comprising: a first end, a second end, and at least one sidewall extending from the first end to the second end; and at least one heating element positioned between an inner surface of the side wall of the housing and an outer surface of the wall of the tubular reactor, wherein the heating element is connected to a second electric current source; and wherein the tubular reactor is at least partially positioned within the housing such that the heating element is operable to heat at least a portion of the tubular reactor when the second current passes through the heating element.

13. The reactor system of claim 12, wherein the heating element is spaced apart from the outer surface of the wall of the tubular reactor, and the side wall of the housing is spaced apart from the outer surface of the wall of the tubular reactor.

14. The reactor system of claim 12 or 13, wherein 2 to 50 tubular reactors according to claim 12 are at least partially positioned within the housing.

15. The reactor system according to any one of claims 12 to 14, wherein the heating element comprises NiCr, SiC, MoSi 2 , graphite or FeCrAl.

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