Electric reactor system for cracking hydrocarbon feed

Abstract

A reactor system includes an enclosure comprising an inflow opening, an outflow opening, and an enclosure wall forming a chamber, wherein the enclosure wall is at least partially made of an insulation material and the chamber is sealed from an outside atmosphere other than through the inflow opening and the outflow opening; and a tubular reactor comprising an inlet, an outlet, and a sidewall extending between the inlet and the outlet, wherein the tubular reactor is heated by applying an electrical current to the sidewall and positioned in the chamber of the enclosure.

Description

ELECTRIC REACTOR SYSTEM FOR CRACKING HYDROCARBON FEEDCROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims the benefit of U.S. Provisional Application Serial No. 63 / 592,788 filed October 24, 2023, the content of which is incorporated in its entirety herein.TECHNICAL FIELD

[0002] Embodiments described herein generally relate to reactor systems for cracking hydrocarbon feed, and particularly are drawn to electric-powered reactor systems for cracking hydrocarbon feed.BACKGROUND

[0003] Electrically heated steam cracker furnaces for cracking hydrocarbon feeds may be desired for various reasons, such as reducing carbon dioxide emissions. Elowever, existing furnace enclosures designed for fired, radiant-heat crackers are poorly suited for use as e-cracker furnace enclosures. In particular, in conventional fired furnaces, hydrocarbon burners are placed in the furnace enclosure near the reactor coils so that the walls of these coils are heated via radiant heat from the burner flames, which produce flue gases (consisting of primarily CO2 and water vapor) that are vented through an exhaust stack. There are substantial heat losses from the enclosure due to the flow of flue gases out of the stack, most of which are recovered via cross-exchange to feed gases in the exhaust stack.

[0004] Accordingly, there is a need for enclosures for use with electrically-powered cracking furnaces.SUMMARY

[0005] Accordingly, there is an ongoing need for improved reactor system comprising an enclosure that is designed to be used with an electrically powered cracker furnace (also referred to herein as an “e-cracker”). Embodiments of the present disclosure meet these needs by utilizing an enclosure at least partially made of an insulation materialand applying an electrical current to a sidewall of a tubular reactor. Thus, the reactor system may improve heat insulation properties. Moreover, embodiments of the present disclosure meet these needs by utilizing a chamber sealedfrom an outside atmosphere other than through an inflow opening and an outflow opening of the enclosure. With the enclosure surrounding the tubular reactor, the reactor system may minimize the heat losses to the ambient atmosphere as well as to prevent any loss of containment in the case of reactor coil leak. Moreover, the present disclosure may eliminate or minimize the risk of hydrocarbon build-up inside the enclosure.

[0006] According to one or more embodiments of the present disclosure, a reactor system comprises an enclosure and a tubular reactor. The enclosure comprises an inflow opening, an outflow opening, and an enclosure wall forming a chamber, wherein the enclosure wall is at least partially made of an insulation materialand the chamber is sealed from an outside atmosphere other than through the inflow opening and the outflow opening. The tubular reactor comprises an inlet, an outlet, and a sidewall extending between the inlet and the outlet, wherein the tubular reactor is heated by applying an electrical current to the sidewall and positioned in the chamber of the enclosure.

[0007] Additional features and advantages of the technology disclosed herein will be set forth in the detailed description, which follows, and in part will be readily apparent to those skilled in the art from that description or recognized by practicing the technology as described herein, including the following detailed description, the claims, as well as the appended drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The following detailed description of specific embodiments of the present disclosure can be best understood when read in conjunction with the following drawings, where like structure is indicated with like reference numerals and in which:

[0009] FIG. 1 schematically depicts a front view of a reactor system comprising a tubular reactor, according to one or more embodiments disclosed herein; and

[0010] FIG. 2 schematically depicts a side view of a reactor system comprising a tubular reactor, according to one or more embodiments described herein.DETAILED DESCRIPTION

[0011] One or more non-limiting embodiments are described herein. In embodiments, a reactor system includes an enclosure comprising an inflow opening, an outflow opening, and an enclosure wall forming a chamber. The enclosure wall is at least partially made of an insulation materialand the chamber is sealed from an outside atmosphere other than through the inflow opening and the outflow opening. The reactor system further includes a tubular reactor comprising an inlet, an outlet, and a sidewall extending between the inlet and the outlet. The tubular reactor is heated by applying an electrical current to the sidewall and positioned in the chamber of the enclosure. Without intending to be bound by theory, by utilizing an enclosure at least partially made of an insulation materialand applying an electrical current to a sidewall of a tubular reactor, the reactor system may improve heat insulation properties. Moreover, having the chamber sealed from an outside atmosphere other than through an inflow opening and an outflow opening of the enclosure, the reactor system may minimize the heat loss to the ambient atmosphere as well as preventing loss of containment in the case of reactor coil leak. Moreover, systems described in the present disclosure may eliminate or minimize the risk of hydrocarbon build-up inside the enclosure. These advantages, as well as others, are described in detail herein below.

[0012] The e-cracker may operate at a maximum system temperature of up to 1100 °C, versus 2000 °C for fired furnaces. Burners may not be needed in embodiments of the e-cracker furnace enclosure and, thus, there may be no flue gases exiting the exhaust stack. A small purge air flow is needed through the e-cracker enclosure to ensure any leakage of hydrocarbons from the coils does not accumulate and cause an overpressure event. This purge air flow may facilitate the need for an exhaust stack that may be small in comparison to the flue gas vent stack found in typical gas-fired furnaces. Tower operating temperatures, the absence of burners, and the use of a small vent stack may result in lower furnace enclosure cost for the e-cracker compared to an enclosure needed for fired furnaces. In accordance with the above, enclosures for e-cracker systems need to be structured to function without the flow of hot flue gas that is prevalent in gas- fired systems. The flue gas not only aids in heating the enclosure, but can also force gas to move through the enclosure providing exhaust and / or combustion of the small amounts of hydrocarbons that leak from the reactor to the enclosure. When an e-cracker is used, there is no flow of flue gas forcing gas flow through the enclosure and, thus, enclosures used for gas-fired processes will allow gas build up of combustible hydrocarbons when used with an e-cracker. The enclosuresdisclosed and described herein solve this problem by being configured to be used with e-cracker technology.

[0013] Referring now to FIGS. 1 and 2, the reactor system 10 comprises an enclosure 100 and a tubular reactor 200. As described herein, a “reactor” refers to a vessel suitable for initiating a given chemical reaction, such as by heating. A “tubular reactor” may refer to a reactor having a substantially tubular shape such that reactants and products pass from an inlet to an outlet of the reactor.

[0014] The enclosure 100 comprises an inflow opening 101, an outflow opening 102, and an enclosure wall 103 forming a chamber 150. The enclosure wall 103 may extend from the inflow opening 101 to the outflow opening 102. In some embodiments, the inflow opening 101 and the outflow opening 102 may not be positioned exactly at an end of the enclosure 100. However, the inflow opening 101 and the outflow opening 102 may be positioned sufficiently close to the ends of the enclosure 100 to not significantly impair the functionally of the enclosure 100. In one or more embodiments, the inflow opening 101 and the outflow opening 102 may be positioned at opposite ends of the enclosure 100.

[0015] The inflow opening 101 and the outflow opening 102 are configured to open when the pressure in the chamber 150 is greater than atmospheric pressure. The opening and closing of the inflow opening 101 and the outflow opening 102 may be conducted by any suitable mechanism, such as a valve that is automated to open when the pressure in the chamber 150 exceeds a pre-set pressure or a mechanical pressure release valve. The inflow opening 101 and the outflow opening 102 may allow gases, such as air, to flow in to and out of the enclosure 100.

[0016] The enclosure 100 may form a chamber 150. The chamber 150 may be sealed from an outside atmosphere other than through the inflow opening 101 and the outflow opening 102. According to embodiments, the atmosphere in the chamber 150 may be air. However, in other embodiments, the atmosphere in the chamber 150 may be other process gases or an inert gas. During normal operating conditions, the atmosphere in the chamber 150 may be operated in a partial recirculation or total recirculation through the inflow opening 101 and the outflow opening 102 to eliminate potential stagnant zones, which may result in gas build up or temperature inconsistencies, inside the chamber 150 and prevent or minimize the heat losses. When a flammable gas is detected in the atmosphere of the chamber 150, recirculation of gases in thechamber 150 may be stopped to prevent an input of oxygen that can fuel combustion. In the present disclosure, the term “normal condition” may refer to operating conditions where a buoyancy driven circulation of air from outside the reactor system 10 occurs without additional energy or increased heat losses to prevent hydrocarbon build-up in the enclosure 100. For example, if there was zero risk of hydrocarbon build-up inside the enclosure, then the normal condition is to permit zero air flow into or out of the enclosure because this will result in minimum heat loss. Accordingly, the primary purpose of the ventilation flow is to prevent hydrocarbon build-up that may be caused by any leaks in the reactor tubes.

[0017] In embodiments the inflow opening 101 is located at the bottom of the enclosure 100 and the outflow opening 102 is located at the top of the enclosure, which allows for the natural movement of gas through the enclosure 100. The elevated temperature inside the enclosure 100 relative to the ambient condition outside the enclosure 100 may result in a buoyancy driven flow of the hot (lower density) gas inside the enclosure 100 out through the inflow opening 101 and the outflow opening 102. This hot gas exiting the enclosure 100 is replaced by allowing an equal mass flow rate of gas into the enclosure 100 through the inflow opening 101 at the bottom of the enclosure 100. In embodiments, the inflow opening 101 may include louvers or valves or some other adjustable flow restriction mechanism to control, such as regulate or prescribe, the flow of purge gas through the enclosure 100. In embodiments, the outflow opening 102 may optionally be equipped with louvers or some other adjustable flow restriction mechanism to control the flow of hot gas out of the enclosure 100

[0018] If the prescribed amount of airflow through the inflow opening 101 and the outflow opening 102 were to be dictated solely by the density difference between the heated air inside the enclosure 100 and the cooler outside air (i.e., by the hot air rising out the outflow opening 102 at the top of the enclosure 100), then the pressure inside the vessel would be slightly sub-atmospheric, such as 10 mm to 50 mm water column under pressure, at the bottom of the vessel and slightly super-atmospheric at the top of the enclosure 100.

[0019] Minimum air flow rate in the enclosure 100 may be needed to fully combust any hydrocarbon introduced from the reactor tubes and into the enclosure, such as through a pinhole leak in the reactor tube. By continuously combusting small amounts of hydrocarbons leaked into the enclosure from the reactor tubes, large-scale, catastrophic combustion can be avoided. Underthe normal condition, air may come in and out of the enclosure 100 via the inflow opening 101 and the outflow opening 102. During any tube damage or failure event, the oxygen present in air may combust any hydrocarbon leaks instantaneously.

[0020] In embodiments, the enclosure wall 103 is at least partially made of insulation material. In some embodiments, the insulation material may include ceramic, refractory, fire bricks, or combinations thereof. In some embodiments, the entire enclosure wall 103 may be made of ceramic. In some embodiments, the enclosure wall 103 may be made of ceramic fiber blocks or at least the interior surface 111 of the enclosure wall 103 is made from one or more ceramic fiber blankets.

[0021] In some embodiments, a temperature of an interior surface 111 of the enclosure wall 103 exposed to the chamber 150 is greater than or equal to 500 °C, greater than or equal to 600 °C, greater than or equal to 700 °C, or greater than or equal to 800 °C. In some embodiments, a temperature of an interior surface 111 of the enclosure wall 103 exposed to the chamber 150 is less than or equal to 1400 °C, less than or equal to 1300 °C, less than or equal to 1200 °C, or less than or equal to 1100 °C. A temperature of an interior surface 111 of the enclosure wall 103 exposed to the chamber 150 may be from 500 °C to 1400 °C, from 500 °C to 1300 °C, from 500 °C to 1200 °C, from 500 °C to 1100 °C, from 600 °C to 1400 °C, from 600 °C to 1300 °C, from 600 °C to 1200 °C, from 600 °C to 1100 °C, from 700 °C to 1400 °C, from 700 °C to 1300 °C, from 700 °C to 1200 °C, from 700 °C to 1100 °C, from 800 °C to 1400 °C, from 800 °C to 1300 °C, from 800 °C to 1200 °C, from 800 °C to 1100 °C, or any and all sub-ranges formed from any of these endpoints.

[0022] In some embodiments, a temperature of an outer surface 112 of the enclosure wall 103 is greater than or equal to 45 °C, greater than or equal to 50 °C, greater than or equal to 55 °C, or greater than or equal to 60 °C. In some embodiments, a temperature of an outer surface 112 of the enclosure wall 103 is less than or equal to 120 °C, less than or equal to 110 °C, less than or equal to 105 °C, or less than or equal to 100 °C. A temperature of an outer surface 112 of the enclosure wall 103 exposed to the chamber 150 may be from 45 °C to 120 °C, from 45 °C to 110 °C, from 45 °C to 105 °C, from 45 °C to 100 °C, from 50 °C to 120 °C, from 50 °C to 110 °C, from 50 °C to 105 °C, from 50 °C to 100 °C, from 55 °C to 120 °C, from 55 °C to 110 °C, from 55 °C to 105 °C, from 55 °C to 100 °C, from 60 °C to 120 °C, from 60 °C to 110 °C, from 60 °C to 105 °C, from 60 °C to 100 °C, or any and all sub-ranges formed from any of these endpoints.

[0023] During the normal condition, a pressure within the enclosure 100 may be less than or equal to atmospheric. The enclosure 100 may be designed to operate greater than or equal to atmospheric pressure by 0.00001 megapascal (MPa). In some embodiments, a pressure within the enclosure 100 may be less than or equal to 0.10 MPa, less than or equal to 0.05 MPa, less than or equal to 0.01 MPa, less than or equal to 0.005 MPa, less than or equal to 0.001 MPa, or less than or equal to 0.0005 MPa. In some embodiments, a pressure within the enclosure 100 may be greater than or equal to 0.00001 MPa, greater than or equal to 0.00005 MPa, or greater than or equal to 0.0001 MPa. A pressure within the enclosure 100 may be from 0.00001 MPa to 0.10 MPa, from 0.00001 MPa to 0.05 MPa, from 0.00001 MPa to 0.01 MPa, from 0.00001 MPa to 0.005 MPa, from 0.00001 MPa to 0.001 MPa, from 0.00001 MPa to 0.0005 MPa, from 0.00005 MPa to 0.10 MPa, from 0.00005 MPa to 0.05 MPa, from 0.00005 MPa to 0.01 MPa, from 0.00005 MPa to 0.005 MPa, from 0.00005 MPa to 0.001 MPa, from 0.00005 MPa to 0.0005 MPa, from 0.0001 MPa to 0.10 MPa, from 0.0001 MPa to 0.05 MPa, from 0.0001 MPa to 0.01 MPa, from 0.0001 MPa to 0.005 MPa, from 0.0001 MPa to 0.001 MPa, from 0.0001 MPa to 0.0005 MPa, or any and all sub-ranges formed from any of these endpoints.

[0024] In some embodiments, the enclosure wall 103 may further include one or more heating elements 104. In embodiments, the enclosure wall 103 may further include one heating element 104, two heating elements 104, three heating elements 104, four heating elements 104, five heating elements 104, or six heating elements 104. It should be understood that the number of heating elements is not particularly limited and will be determined by the heat load requirements. According to one or more embodiments, when multiple heating elements 104 are positioned within the enclosure 100, the heating elements 104 may be controlled in groups or even individually. Separate control of groups of heating elements 104 may allow for various heating zones to be independently controlled within the enclosure 100. In embodiments, the heating elements 104 may be configured to heat the atmosphere within the chamber 150. In one or more embodiments, the heating element 104 may be configured to heat the enclosure wall 103.

[0025] The heating element 104 may be disposed on the enclosure wall 103. In embodiments, the heating element 104 may be configured to facilitate a rate of heating sufficient to drive the buoyancy induced ventilation as described above, in the event the primary heating source, such as the heating element 220 are not operating. The primary heating source may refer to a heating source that heats the tubular reactor 200. The heating elements 104 may be providedto prevent hydrocarbon build-up in the event the primary heating source, such as the heating element 220, is not operational or cannot provide sufficient heat to one or more portions of the chamber 150.

[0026] In embodiments, the at least one heating element 104 may include metal, graphite, a ceramic material, or combinations thereof. In some embodiments, the metal may include nichrome alloy. In one or more embodiments, the at least one heating element 104 may comprise NiCr, SiC, MoSi2, graphite, or FeCrAl as a resistive material through which electrical current is passed to generate heat. In one or more embodiments, the at least one heating element 104 may comprise silicon carbide (SiC). In one or more embodiments, the at least one heating element 104 may take any suitable form. For example, and without limitation, the at least one heating element 104 may comprise a round wire, a flat wire, twisted wires, strips, rods, rod over band, etc. In one or more embodiments, the heating element 220 may be resistant to exposure to air, hydrocarbons, and steam. Without intending to be bound by theory, the heating elements may be resistant to hydrocarbons and steam so they are not damaged in the event that hydrocarbons or steam are released by a failure of one of the tubular reactors that results in the release of reactants, products, or both. However, it should be noted that suitable heating elements are not limited solely to those that are resistant to exposure to hydrocarbons or steam.

[0027] In one or more embodiments, the at least one heating element 104 may have a resistivity from 0.1 to 5 pQ m at 1100 °C, from 0.1 to 3 pQ m at 1100 °C, from 0.1 to 2 pQ m at 1100 °C, from 0.5 to 5 pQ m at 1100 °C, from 0.5 to 3 pQ m at 1100 °C, from 0.5 to 2 pQ m at 1100 °C, or any and all sub-ranges formed from any of these endpoints.

[0028] In some embodiments, the enclosure 100 may further include at least one port for monitoring at least one of the pressure, temperature, or composition of the atmosphere in the chamber 150. The at least one port may be a sealed opening in which a device for measuring the pressure, temperature, or composition of the atmosphere may be inserted, such as probes, thermocouples, and the like. In embodiments, the port may be configured so that the device is permanently mounted in the port (i.e., only replaced for maintenance or failure). In other embodiments the port may be configured so that a device may be inserted to conduct the desired measurement and then removed. In embodiments, the port is sealed so that gases from the atmosphere do not leak into the chamber 150 through the port. The at least one port may be usedmonitor all or any one of the pressure, temperature, or composition of the atmosphere in the chamber 150.

[0029] In embodiments, the enclosure 100 may further include at least one infrared camera. In embodiments, the at least one infrared camera may be used to measure the temperature of surfaces within the enclosure. In some embodiments, the at least one infrared cameras may be mounted at the corners of the enclosure 100 to monitor the temperature of the tubular reactor 200.

[0030] In embodiments, the enclosure 100 may further include windows for monitoring the temperature of the tubular reactor 200, such as thermocouples, a laser thermometer or infrared camera.

[0031] The enclosure wall 103 may be spaced apart from an exterior surface 212 of the sidewall 203. In embodiments, the interior surface 111 of the enclosure wall 103 may be spaced apart from the exterior surface 212 of the sidewall 203. The interior surface 111 of the enclosure wall 103 may not be in direct contact with the exterior surface 212 of the sidewall 203 of the tubular reactor 200. In such an embodiment, conductive heating may not be possible on the tubular reactor 200 by the at least one heating element 104.

[0032] Still referring to FIGS. 1 and 2, the tubular reactor 200 includes an inlet 201, an outlet 202, and a sidewall 203 extending between the inlet 201 and the outlet 202. The sidewall 203 includes an exterior surface 212 and an interior surface 211. A hydrocarbon feed stream may be introduced to the tubular reactor 200 through the inlet 201. At least a portion of the hydrocarbon feed stream within the tubular reactor 200 may be reacted to form a product stream which is passed through the tubular reactor 200 and exits through the outlet 202 of the tubular reactor 200. It should be noted that reacting the hydrocarbon feed stream to form a product stream may include performing any endothermic reaction. In some embodiments, the endothermic reaction may be a steam cracking reaction, a steam reforming reaction, or a hydroprocessing reaction. However, it should be noted that the methods for processing chemicals described herein are not necessarily limited to such reactions.

[0033] In some embodiments, the reaction may be a steam cracking reaction. However, the described embodiments may have applicability to a wide range of chemical processes. As described herein, a “steam cracking reaction” refers to the thermal cracking of hydrocarbons inthe presence of steam to produce products such as hydrogen, olefins, and aromatic hydrocarbons. Without intending to be bound by theory, the pyrolysis reaction of hydrocarbons follows a free radical mechanism, requiring high temperatures. Steam may act as a diluent to reduce the partial pressure of hydrocarbons, which may improve selectivity by promoting higher yields of light olefins.

[0034] In embodiments, the hydrocarbon feed stream may comprise at least one of methane, ethane, propane, and butane. In some embodiments, the hydrocarbon feed stream may comprise naphtha or vacuum gas oil. In some embodiments, the hydrocarbon feed stream may comprise Ci to Cs hydrocarbons, Ci to C20 hydrocarbons, or even Ci to C50 hydrocarbons. In some embodiments, the hydrocarbon feed stream may further comprise water or steam (H2O), CO2, CO, N2, CO, CO2, H2, or combinations thereof. In embodiments, methane may not react in the tubular reactor 200 and pass the tubular reactor 200 as inert.

[0035] In one or more embodiments, the product stream may comprise at least one of hydrogen, olefins, and aromatic hydrocarbons. The product stream may comprise 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 may comprise C2 to C10 olefins, from C2 to C20 olefins, or even from C2 to C50 olefins. In one or more embodiments, the product stream may comprise aromatic hydrocarbons such as benzene and its derivatives. The product stream may comprise benzene, toluene, ethylbenzene, o-xylene, p-xylene, m-xylene, mesitylene, durene, 2-phenylhexane, biphenyl, or combinations thereof.

[0036] In one or more embodiments, the product stream may comprise greater than 15 wt.%, greater than 20 wt.%, greater than 25 wt.%, greater than 30 wt.%, greater than 35 wt.%, or greater than 40 wt.% olefins, aromatic hydocarbons, or combinations thereof. For example, and without limitation the product stream may comprise from 15 wt.% to 100 wt.%, from 20 wt.% to 100 wt.%, from 30 wt.% to 100 wt.%, from 40 wt.% to 100 wt.%, from 50 wt.% to 100 wt.%, from 60 wt.% to 100 wt.%, from 70 wt.% to 100 wt.%, from 80 wt.% to 100 wt.%, from 90 wt.% to 100 wt.%, from 20 wt.% to 90 wt.%, from 20 wt.% to 80 wt.%, from 20 wt.% to 70 wt.%, from 20 wt.% to 60 wt.%, from 20 wt.% to 50 wt.%, from 20 wt.% to 40 wt.%, from 20 wt.% to 30 wt.%, or any combination or subset of these ranges of olefins, aromatic hydrocarbons, or combinations thereof.

[0037] The sidewall 203 may extend from at least the inlet 201 to the outlet 202 of the tubular reactor 200. In one or more embodiments, the sidewall 203 may extend from the inlet 201 to the outlet 202 of the tubular reactor 200. In such embodiments, the inlet 201 and the outlet 202 may be positioned at opposite ends of the tubular reactor 200. In one or more embodiments, which are not depicted, the sidewall 203 may extend past the inlet 201 or the outlet 202 or both. In such embodiments, the inlet 201 or the outlet 202 may not be positioned exactly at an end of the tubular reactor 200. However, the inlet 201 and the outlet 202 may be positioned sufficiently close to the ends of the tubular reactor 200 to not significantly impair the functionality of the tubular reactor 200. For example, the inlet 201 or the outlet 202 may be an opening in the sidewall 203 of the tubular reactor 200 proximate an end of the tubular reactor 200 while the end of the tubular reactor 200 is closed. The tubular reactor 200 is positioned in the chamber 150 of the enclosure 100. In some embodiments, the tubular reactor 200 may be coil-shaped.

[0038] In embodiments, the tubular reactor 200 is operated at a temperature of greater than or equal to 500 °C, greater than or equal to 600 °C, greater than or equal to 700 °C, or greater than or equal to 800 °C. In some embodiments, the tubular reactor 200 is operated at a temperature of less than or equal to 1400 °C, less than or equal to 1300 °C, less than or equal to 1200 °C, or less than or equal to 1100 °C. The tubular reactor 200 may be operated at a temperature of from 500 °C to 1400 °C, from 500 °C to 1300 °C, from 500 °C to 1200 °C, from 500 °C to 1100 °C, from 600 °C to 1400 °C, from 600 °C to 1300 °C, from 600 °C to 1200 °C, from 600 °C to 1100 °C, from 700 °C to 1400 °C, from 700 °C to 1300 °C, from 700 °C to 1200 °C, from 700 °C to 1100 °C, from 800 °C to 1400 °C, from 800 °C to 1300 °C, from 800 °C to 1200 °C, from 800 °C to 1100 °C, or any and all sub-ranges formed from any of these endpoints.

[0039] In embodiments, the sidewall 203 may further include one heating element 220, two heating elements 220, three heating elements 220, or four heating elements 220. It should be understood that the number of heating elements is not particularly limited and will be determined by the heat load requirements. According to one or more embodiments, when multiple heating elements 220 are positioned within the tubular reactor 200, the heating elements 220 may be controlled in groups or even individually. Separate control of groups of heating elements 220 may allow for various heating zones to be independently controlled within the tubular reactor 200.

[0040] The tubular reactor 200 is heated by applying an electrical current to the sidewall 203. The sidewall 203 may be connected to at least one heating element 220. The at least one heating element 220 may be an electrical current source. The at least one heating element 220 may be any suitable source of electrical current. The at least one heating element 220 may be operable to provide alternating current or direct current to the sidewall 203 of the tubular reactor 200. For example, without any limitation, a suitable one heating element 220 may be a commercially available power step-down transformer.

[0041] In embodiments, applying the electrical current through the sidewall 203 may heat the sidewall 203 of the tubular reactor 200 by electric resistance heating. Without being bound by theory, electric resistance heating may take place by means of the “Joule effect.” According to Joule’s first law, the power of heating generated by an electrical conductor is proportional to the product of its resistance 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.P = I2R Equation 1.

[0042] In one or more embodiments, applying an electrical current to the sidewall 203 may heat at least a portion of the sidewall 203 of the tubular reactor 200. The sidewall 203 of the tubular reactor 200 may be heated to a temperature sufficient so that the operating temperature of tubular reactor 200 disclosed above is reached.

[0043] In some embodiments, the sidewall 203 of the tubular reactor 200 may be electrically conductive. In embodiments, the tubular reactor 200 and the enclosure 100 are connected through at least one reactor support 300. In some embodiments, the tubular reactor 200 and the enclosure 100 are connected through two reactor supports 300. The at least one reactor support 300 may be disposed between a top of the tubular reactor 200 and a top of the enclosure 100.

[0044] In one or more embodiments, heat may be transferred from the heating element 220 to the sidewall 203 of the tubular reactor 200 by radiation, convection, or combinations of these. For example, and without limitation, heat may radiate from the surface of the heating element 220 directly to the exterior surface 212 of the sidewall 203 of the tubular reactor 200. Additionally, gases contained within the enclosure 100 may be heated by the heating element 220 and heat the sidewall 203 of the tubular reactor 200 by convection.

[0045] As described herein, the sidewall 203 of the tubular reactor 200 may be heated by electric resistance heating of the sidewall 203 of the tubular reactor 200 and by radiative heating from the heating element 220. In one or more embodiments, the heating element 220 may provide from 10% to 50% of the heat to the sidewall 203 of the tubular reactor 200. For example, the heating element 220 may provide from 10% to 50%, from 20% to 50%, from 30% to 50%, from 40% to 50%, from 10% to 40%, from 10% to 30%, from 10% to 20%, or any combination or subset of these values, of the heat to the sidewall 203 of the tubular reactor 200.

[0046] In one or more embodiments, resistance heating of the sidewall 203 of the tubular reactor 200 may provide from 50% to 90% of the heat to the sidewall 203 of the tubular reactor 200. For example, resistance heating of the sidewall 203 of the tubular reactor 200 may provide from 50% to 90%, from 60% to 90%, from 70% to 90%, from 80% to 90%, from 50% to 80%, from 50% to 70%, from 50% to 60%, or any combination or subset of these values, of the heat to the sidewall 203 of the tubular reactor 200.

[0047] It should be noted that method steps set forth herein should not be construed as requiring that the steps be performed in a specific order, unless otherwise specified. For example, and without limitation, it is contemplated that in a method for processing chemicals described herein, the method steps of 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 and passing a second electrical current through the heating element to heat at least a portion of the heating element do not necessarily have to be performed in any particular order, and a claim reciting these method steps should not be construed as requiring them in any particular order. It is contemplated that in one or more embodiments described herein the method steps of passing a first electrical current through at least a portion of the wall of the tubular reactor and passing a second electrical current through the heating element may occur at any point in a method for processing chemicals described herein. Specifically, such method steps may occur before, during, and after passing a hydrocarbon feed stream through the inlet of the tubular reactor, before, during, and after the hydrocarbon feed stream is reacted to form a product stream, and before, during, and after the product stream is being passed from the tubular reactor.

[0048] It is noted that one or more of the following claims utilize the term “wherein” as a transitional phrase. For the purposes of defining the present technology, it is noted that this termis introduced in the claims as an open-ended transitional phrase that is used to introduce a recitation of a series of characteristics of the structure and should be interpreted in like manner as the more commonly used open-ended preamble term “comprising.”

[0049] 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” or “consists essentially of’ that second component. It should further be understood that where a first component is described as “comprising” a second component, it is contemplated that, in some embodiments, the first component comprises 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% that second component (where % can be weight % or molar %).

[0050] Additionally, the term “consisting essentially of’ is used in this disclosure to refer to quantitative values that do not materially affect the basic and novel characteristic(s) of the disclosure. For example, a chemical composition “consisting essentially” of a particular chemical constituent or group of chemical constituents should be understood to mean that the composition includes at least about 99.5% of a that particular chemical constituent or group of chemical constituents.

[0051] 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 particular embodiment or to any other embodiment. Further, it should be apparent to those skilled in the art that various modifications and variations can be made to the described embodiments without departing from the spirit and scope of the claimed subject matter.

Claims

CLAIMS1. A reactor system comprising: an enclosure comprising an inflow opening, an outflow opening, and an enclosure wall forming a chamber, wherein the enclosure wall is at least partially made of an insulation materialand the chamber is sealed from an outside atmosphere other than through the inflow opening and the outflow opening; and a tubular reactor comprising an inlet, an outlet, and a sidewall extending between the inlet and the outlet, wherein the tubular reactor is heated by applying an electrical current to the sidewall and positioned in the chamber of the enclosure.

2. The reactor system of claim 1, wherein the tubular reactor is operated at a temperature of from 700 °C to 1100 °C.

3. The reactor system of any of the preceding claims, wherein a temperature of an interior surface of the enclosure wall exposed to the chamber is from 700 °C to 1100 °C.

4. The reactor system of any of the preceding claims, wherein a temperature of an outer surface of the enclosure wall exposed to the outside atmosphere is from 30 °C to 100 °C.

5. The reactor system of any of the preceding claims, wherein the enclosure wall is spaced apart from an exterior surface of the reactor wall.

6. The reactor system of any of the preceding claims, wherein the tubular reactor is coilshaped.

7. The reactor system of any of the preceding claims, wherein a pressure within the enclosure is less than 0.10 megapascal (MPa).

8. The reactor system of any of the preceding claims, wherein a pressure within the enclosure is from 0.00001 MPa to 0.0005 MPa.

9. The reactor system of any of the preceding claims, wherein the enclosure wall further comprises at least one heating element configured to heat at least a portion of an atmosphere within the chamber.

10. The reactor system of claim 9, wherein the at least one heating element comprises metal, graphite, or both.

11. The reactor system of any of the preceding claims, wherein the inflow opening and the outflow opening are configured to open when the pressure in the chamber is greater than atmospheric pressure.

12. The reactor system of any of the preceding claims, wherein the tubular reactor the enclosure are connected through at least one reactor support.

13. The reactor system of any of the preceding claims, wherein an atmosphere in the chamber is air.

14. The reactor system of any of the preceding claims, wherein the enclosure further comprises at least one port for monitoring at least one of the pressure, temperature, or composition of the atmosphere in the chamber.

15. The reactor system of any of the preceding claims, wherein the enclosure further comprises windows for monitoring the temperature of the tubular reactor.

Images