Process for direct heating of electric tubes to improve the quality of hydrocarbons

Abstract

A process for upgrading a hydrocarbon fluid, the process comprising: introducing a first portion of the hydrocarbon fluid into a first conductive tube; introducing a second portion of the hydrocarbon fluid into a second conductive tube; applying a DC current to the first conductive tube to heat the first portion of the hydrocarbon fluid in the first tube to a first reaction temperature to form a first product stream; applying a DC current to the second conductive tube to heat the second portion of the hydrocarbon fluid in the second tube to a second reaction temperature to form a second product stream; introducing the first product stream into a product channel through an outlet of the first conductive tube; and introducing the second product stream into a product channel through an outlet of the second conductive tube.

Description

[Technical Field]

[0001] FIELD OF THE DISCLOSURE Embodiments of the present disclosure generally relate to systems and processes for upgrading hydrocarbons. [Background technology]

[0002] Ethylene is widely used as an intermediate in the petrochemical industry, and its production exceeds that of any other organic compound. Much of the ethylene product is utilized in the production of ethylene oxide, ethylene dichloride, and polyethylene, which are precursors to many everyday consumer products. Despite numerous improvements over the years in thermal efficiency, reliability, and safety, steam cracking furnaces used to form hydrocarbons such as ethylene remain heavily reliant on the combustion of fossil fuels to provide process heat, resulting in substantial greenhouse gas emissions.

[0003] The steam cracking process for producing ethylene requires approximately half the energy required by competing processes (e.g., direct C1 conversion technologies) and is expected to remain the most energy-efficient process. CO2 emissions from ethane steam cracking range from 0.76 to 1.06 tonnes of CO2 per tonne of ethylene produced, lower than those from naphtha steam cracking, making it an alternative C1-based route to ethylene. At planned rates of ethylene production, CO2 emissions from conventional steam cracking could exceed 300 Mta-CO2 in the next few years. Approximately 85% of CO2 emissions in the steam cracking process are emitted in the radiant furnace section. In conventional radiant furnaces, multiple fuel gas burners are deployed to efficiently radiate heat from the combustion process through the walls of a tubular reactor containing flowing feedstocks (e.g., hydrocarbons and steam) and product gases, providing heat for the necessary endothermic chemical reactions.

[0004] The increasing availability of renewable electricity offers opportunities for using renewable energy in the formation of ethylene, eliminating the need to burn fossil fuels and achieving a lower-emissions process. Various electrical heating technologies, such as impedance, induction, plasma, and microwave, can be used in place of combustion-fired heating to generate and effectively transfer heat to the radiant coils of a steam cracking furnace. However, there remains a need for a system capable of forming ethylene and other hydrocarbons via heating from renewable sources. Summary of the Invention

[0005] The application of direct electric heating to large-scale steam cracking processes requires large amounts of electrical current and power. A significant challenge is how to efficiently and strategically apply direct electric heating to large-scale steam crackers via multi-conduit heaters that require hundreds of megawatts of power. The disclosed heating apparatus reduces the total current requirements of the power supply by half while avoiding the use of electrical isolation devices (such as insulating flanges) and creates multiple heating zones to deliver finely tuned power and heat loads to each conductive tube of the heating apparatus. Reducing the current requirements increases the efficiency of the power supply and associated electrical connections and support equipment. Furthermore, facilitating fine-tuning of the heat injection rate into the conductive tubes increases the yield of desired products.

[0006] An embodiment of the present disclosure includes a heating device comprising a pair of electrically conductive tubes, a feed channel having a fluid inlet and a ground connection, a product channel having a fluid outlet and a ground connection, and a DC current voltage source. The feed channel is fluidly connected to the inlet of the pair of electrically conductive tubes, and the product channel is fluidly connected to the outlet of the pair of electrically conductive tubes. The pair of electrically conductive tubes includes a first electrically conductive tube and a second electrically conductive tube connected in series, and the DC current voltage source is electrically connected to the first electrically conductive tube and the second electrically conductive tube.

[0007] An additional embodiment of the present disclosure includes a process for upgrading a hydrocarbon fluid, the process including introducing the hydrocarbon fluid into a fluid inlet of a feed channel, introducing a first portion of the hydrocarbon fluid into the inlet of a first conductive tube, and introducing a second portion of the hydrocarbon fluid into the inlet of a second conductive tube. The process further includes applying a DC current to the first conductive tube to heat the first portion of the hydrocarbon fluid in the conductive tube to a reaction temperature to form a first product stream, and applying a DC current to the second conductive tube to heat the second portion of the hydrocarbon fluid in the conductive tube to a reaction temperature to form a second product stream. The process further includes introducing the first product stream into a product channel through an outlet of the first conductive tube and introducing the second product stream into the product channel through an outlet of the second conductive tube. [Brief explanation of the drawings]

[0008] The following detailed description of certain embodiments of the present disclosure can be best understood when read in conjunction with the following drawings. [Figure 1] 1 is a schematic diagram of a process and apparatus for upgrading hydrocarbons according to the present embodiments. [Figure 2A] 1 is a first side view of an apparatus for upgrading hydrocarbons according to an embodiment; FIG. [Figure 2B] FIG. 2 is a second side view of an apparatus for upgrading hydrocarbons according to the present embodiment. [Figure 3A] 1 is a first plan view of an apparatus for upgrading hydrocarbons according to an embodiment; FIG. [Figure 3B] FIG. 2 is a second plan view of an apparatus for upgrading hydrocarbons according to the present embodiment. [Figure 4A] 1 illustrates a U-shaped conductive tube of an apparatus for upgrading hydrocarbons according to an embodiment. [Figure 4B] 1 illustrates a double U-shaped conductive tube of an apparatus for upgrading hydrocarbons according to an embodiment. [Figure 5A] 1 illustrates a W-shaped conductive tube of an apparatus for upgrading hydrocarbons according to an embodiment. [Figure 5B] 1 illustrates a double W-shaped conductive tube of an apparatus for upgrading hydrocarbons according to an embodiment. [Figure 6] 1 is a graphical representation of ethylene yield versus cracking temperature according to the present embodiments. [Figure 7] 1 is a graphical representation of a process gas temperature profile according to the present embodiments. [Figure 8] 1 is a graphical representation of ethylene yield according to the present embodiments. DETAILED DESCRIPTION OF THE INVENTION

[0009] Embodiments of the present disclosure are directed to a process for upgrading a hydrocarbon fluid, the process including: introducing the hydrocarbon fluid into a fluid inlet of a feed channel; introducing a first portion of the hydrocarbon fluid into the inlet of a first conductive tube; introducing a second portion of the hydrocarbon fluid into the inlet of a second conductive tube; applying a DC current to the first conductive tube to heat the first portion of the hydrocarbon fluid in the first conductive tube to a first reaction temperature to form a first product stream; applying a DC current to the second conductive tube to heat the second portion of the hydrocarbon fluid in the second conductive tube to a second reaction temperature to form a second product stream; introducing the first product stream into a product channel through an outlet of the first conductive tube; and introducing the second product stream into the product channel through an outlet of the second conductive tube.

[0010] Embodiments of the present disclosure are also directed to the above-described process, wherein applying a DC current to a first conductive tube provides a total heat load to the first conductive tube, with greater than 50%, e.g., 60% to 85%, of the total heat load being provided to a first half of the first conductive tube, and applying a DC current to a second conductive tube provides a total heat load to the second conductive tube, with greater than 50%, e.g., 60% to 85%, of the total heat load being provided to a first half of the second conductive tube.

[0011] It is understood that the presently disclosed process for upgrading hydrocarbons may be embodied in different forms and should not be construed as limited to the specific embodiments set forth in this disclosure. Rather, the embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the subject matter to those skilled in the art.

[0012] Specific embodiments will now be described with reference to the drawings.

[0013] FIG. 1 illustrates a schematic of a heating apparatus 100 for upgrading hydrocarbons from a hydrocarbon fluid 202 according to embodiments described herein.

[0014] Heating apparatus 100 includes a pair of conductive tubes (as shown in FIG. 1, this pair may include 220a and 220b), a feed channel 210, a product channel 214, and a DC current voltage source 120. Feed channel 210 has a fluid inlet 212 and a ground connection 140, and is fluidly connected to inlet 211 of conductive tube pair 220a, 220b. Similarly, product channel 214 has a fluid outlet 216 and a ground connection 140, and is fluidly connected to outlet 215 of conductive tube pair 220a, 220b.

[0015] In embodiments, power supply 110 may be provided to transformer 112. Transformer 112 may be any transformer known in the art for transferring electrical energy from one electrical circuit to another. In embodiments, transformer 112 may be a power step-down converter that reduces the voltage level of the power to form reduced-voltage power 114 that is provided to DC current / voltage source 120. Power step-down converter 112 and associated DC current / voltage source 120 may use semiconductor technologies such as thyristors, diodes, insulated-gate bipolar transistors (IGBTs), integrated gate-commutated thyristors (IGCTs), etc., commercially available from companies such as Fuji Electric Co., Ltd. or ABB and commonly used by the electrochemical or metallurgical industries. While transformer 112 and DC current / voltage source 120 are shown as separate units in FIG. 1 for clarity, it should be understood that in embodiments, these components may be integrated into a single unit.

[0016] As shown in FIG. 1 , a conductive tube pair includes a first conductive tube 220a and a second conductive tube 220b connected in series. As used throughout this disclosure, 220a and 220b will be used to refer to the conductive tube pair or each component of the conductive tube pair, respectively, as the terms “first conductive tube” and “second conductive tube.” However, this is not meant to be limited to a specific pair of conductive tubes or the first pair of conductive tubes, but is meant to refer generally to any pair of conductive tubes or any component of a conductive tube pair. In embodiments (such as those shown in FIG. 1 ), there may be additional pairs of conductive tubes, such as a second pair including 220a and 220b. In embodiments (not shown), there may be more than two pairs of conductive tubes. In the embodiment, the heating device 100 may be configured to have a number of pairs of heating elements, such as 2 to 100 pairs, 2 to 75 pairs, 2 to 60 pairs, 2 to 50 pairs, 2 to 40 pairs, 2 to 35 pairs, 2 to 30 pairs, 2 to 25 pairs, 2 to 20 pairs, 2 to 15 pairs, 2 to 10 pairs, 2 to 5 pairs, 5 to 100 pairs, 5 to 75 pairs, 5 to 60 pairs, 5 to 50 pairs, 5 to 40 pairs, 5 to 35 pairs, 5 to 30 pairs, 5 to 25 pairs, 5 to 20 pairs, Pairs, 5-15 pairs, 5-10 pairs, 10-100 pairs, 10-75 pairs, 10-60 pairs, 10-50 pairs, 10-40 pairs, 10-35 pairs, 10-30 pairs, 10-25 pairs, 10-20 pairs, 10-15 pairs, 15-100 pairs, 15-75 pairs, 15-60 pairs, 15-50 pairs, 15-40 pairs, 15-35 pairs, 15-30 pairs, 15-25 pairs , 15-20 pairs, 20-100 pairs, 20-75 pairs, 20-60 pairs, 20-50 pairs, 20-40 pairs, 20-35 pairs, 20-30 pairs, 20-25 pairs, 25-100 pairs, 25-75 pairs, 25-60 pairs, 25-50 pairs, 25-40 pairs, 25-35 pairs, 25-30 pairs, 30-100 pairs, 30-75 pairs, 30-60 pairs, 30-5 The number of conductive tubes may be 0 pairs, 30 to 40 pairs, 30 to 35 pairs, 35 to 100 pairs, 35 to 75 pairs, 35 to 60 pairs, 35 to 50 pairs, 35 to 40 pairs, 40 to 100 pairs, 40 to 75 pairs, 40 to 60 pairs, 40 to 50 pairs, 50 to 100 pairs, 50 to 75 pairs, 50 to 60 pairs, 60 to 100 pairs, 60 to 75 pairs, or 75 to 100 pairs.In embodiments in which the heating apparatus 100 includes at least two pairs of conductive tubes, the first pair of conductive tubes and the second pair of conductive tubes may be physically positioned parallel to one another on a horizontal axis, a distance (d) apart, as shown.

[0017] In embodiments, the first conductive tube, the second conductive tube, or both may have a curvature along their length. The shape of each conductive tube may be modified to resemble, for example, the letter M, W, U, inverted U, I, or combinations thereof. It is desirable that each conductive tube connected to the power supply 110 have a similar shape and geometry, be made of a similar material, and have an electrical resistance value within plus or minus 10% of the new material's specified range at room and operating temperatures to ensure that the power output required for each conductive tube is within a desired range of approximately + / - 11% and, therefore, that the heat flux to all conduits is within a narrower range (plus or minus 11% of the average value) compared to the heat flux delivered to conduits in existing conventional combustion-fired furnaces, which can vary as much as 100% throughout the furnace. The uniform heat flux of the conductive tubing results in more uniform conduit temperatures, resulting in lower maximum conduit temperatures—both along a single conduit within the furnace and across adjacent conduits—compared to those observed in conventionally fired furnaces. Lowering the maximum conduit temperature allows for higher average conduit temperatures, which improves reactant conversion and increases selectivity to the desired product (ethylene). Improved control of the maximum temperature of the conductive cracking conduits results in a slower rate of coke buildup on the inner conduit walls. Conduits operating without coke buildup have a higher heat transfer coefficient, which contributes to cooling the conduit, further limiting conduit overheating. Lower coking rates translate into longer operating run times and fewer costly furnace shutdowns required to decoke the conduits, so longer overall conduit life can be expected from the use of conductive tubing.

[0018] In an embodiment, any pair of conductive tubes has a resistance of 1.0 to 4.0 μΩ·m at 900°C, 1.0 to 3.5 μΩ·m at 900°C, 1.0 to 3.0 μΩ·m at 900°C, 1.0 to 2.5 μΩ·m at 900°C, 1.0 to 2.0 μΩ·m at 900°C, 1.0 to 1.5 μΩ·m at 900°C, 1.5 to 4.0 μΩ·m at 900°C, 1.5 to 3.5 μΩ·m at 900°C, 1.5 to 3.0 μΩ·m at 900°C, 1.5 to 2.5 μΩ·m at 900°C, The conductive tube may have an electrical resistivity of 1.5 to 2.0 μΩ·m at 900° C., 2.0 to 4.0 μΩ·m at 900° C., 2.0 to 3.5 μΩ·m at 900° C., 2.0 to 3.0 μΩ·m at 900° C., 2.0 to 2.5 μΩ·m at 900° C., 2.5 to 4.0 μΩ·m at 900° C., 2.5 to 3.5 μΩ·m at 900° C., 2.5 to 3.0 μΩ·m at 900° C., 3.0 to 4.0 μΩ·m at 900° C., 3.0 to 3.5 μΩ·m at 900° C., or 3.5 to 4.0 μΩ·m at 900° C. In an embodiment, the electrical resistivity of the conductive tube may vary over the length of the conductive tube.

[0019] In embodiments, any conductive tubing may have an inner diameter of 1 to 6 inches (in), 1 to 5 in, 1 to 4 in, 1 to 3 in, 1 to 2 in, 2 to 6 in, 2 to 5 in, 2 to 4 in, 2 to 3 in, 3 to 6 in, 3 to 5 in, 3 to 4 in, 4 to 6 in, 4 to 5 in, or 5 to 6 in. Any conductive tubing may have a wall thickness of 0.1 to 1.5 in, 0.1 to 1.25 in, 0.1 to 1.0 in, 0.1 to 0.75 in, 0.1 to 0.5 in, 0.1 to 0.25 in, 0.25 to 1.5 in, 0.25 to 1.25 in, 0.25 to 1.0 in, 0.25 to 0.75 in, 0.25 to 0.5 in, 0.5 to 1.5 in, 0.5 to 1.25 in, 0.5 to 1.0 in, 0.5 to 0.75 in, 0.75 to 1.5 in, 0.75 to 1.25 in, 0.75 to 1.0 in, 1.0 to 1.5 in, 1.0 to 1.25 in, or 1.25 to 1.5 inches. Any conductive tube may have a length of 10 to 60 meters (m), 10 to 50 m, 10 to 40 m, 10 to 30 m, 10 to 20 m, 20 to 60 m, 20 to 50 m, 20 to 40 m, 20 to 30 m, 30 to 60 m, 30 to 50 m, 30 to 40 m, 40 to 60 m, 40 to 50 m, or 50 to 60 m. In embodiments, the inner diameter, wall thickness, or both may vary over the length of the conductive tube.

[0020] As previously referenced, various properties of the conductive tube can be modified to deliver different heat loads to different sections of the conductive tube. It is believed that modifying the properties of the conductive tube can enable heat delivery to facilitate improved performance. Fine tuning of the power and heat load delivered to the conductive tube can be achieved by adjusting the electrical resistance of a first portion of the conductive tube and the electrical resistance of a second portion of the conductive tube relative to one another. In embodiments, any first portion of the conductive tube can be proximate the inlet 211. Similarly, any second portion of the conductive tube can be proximate the outlet 215. The electrical resistance can be adjusted by adjusting the properties of the portions of the conductive tube, such properties being any of those described herein. It is contemplated that the resistance of each portion of the conductive tube can also be changed by using different materials with different electrical resistances.

[0021] In embodiments, the first conductive tube 220a may be electrically connected to the second conductive tube 220b. In embodiments, the first current bridge link 218a and the second current bridge link 218b are electrically disposed between the first conductive tube 220a and the second conductive tube 220b. The current bridge links 218a, 218b are configured to conduct current across the feed channel 210, the product channel 214, or both. In embodiments, the current bridge links 218a, 218b may be connected to a ground connection 140, as shown in FIG. 1, where the ground connection 140 is shown connected to the current bridge link 218a. While FIG. 1 shows the ground connection 140 connected to the current bridge link 218a, it should be understood that there may be additional or alternative ground connections 140 connected to the other current bridge links 218a, 218b. In an embodiment (not shown), each current bridge link 218 a , 218 b may be connected to a separate or independent ground connection 140 .

[0022] The first and second current bridge links 218a, 218b may comprise a material with a high melting point, low electrical resistance, and are galvanically compatible with the material of the conduits to which they are attached, such as the same material as the conduits. According to an embodiment, the first and second current bridge links 218a, 218b are made from a material with an electrical resistance equal to or less than the resistance of the material used to form the pair of conductive tubes 220a, 220b to limit excess heat generated in the current bridge links.

[0023] The DC current / voltage source 120 is electrically connected to the first conductive tube 220a and the second conductive tube 220b. In an embodiment, the pair of conductive tubes 220a, 220b is configured such that a DC current 130 generated from the DC current / voltage source 120 flows from the first conductive tube 220a to the second conductive tube 220b and from the second conductive tube 220b to the DC current / voltage source 120. In an embodiment, the DC current 130 can flow from the first conductive tube 220a to the second conductive tube 220b through the first and second current bridge links 218a, 218b.

[0024] A DC current and voltage source 120 controls the potential (V p ) twice the output voltage (V o ), allowing the same amount of DC current 130 to power the pair of electrically connected conductive tubes 220a, 220b in series. o ) to the potential (V p ), the output current (I o ) can be equal to the current in each pipe assembly. This allows the inlet 211 and outlet 215 of the pair of conductive tubes 220a, 220b to be electrically grounded to earth via the ground connection 140 to ensure safe operation without requiring the use of electrical isolation means (such as insulating flanges), while at the same time reducing the output current (I o ) is maintained at a minimum level.

[0025] As previously described, each pair of conductive tubes 220a, 220b has an inlet 211 and an outlet 215. Any conductive tube may have one inlet 211 (as shown) or multiple inlets 211 (not shown). In embodiments, any conductive tube may have two, three, four, five, or six inlets 211. Any conductive tube may have one outlet 215 (as shown) or multiple outlets 215 (not shown). In embodiments, any conductive tube may have two, three, four, five, or six outlets 215. In embodiments, each inlet 211 of each pair of conductive tubes 220a, 220b has a zero potential. Additionally or alternatively, in embodiments, each outlet 215 of each pair of conductive tubes 220a, 220b has a zero potential. The inlet 211 and / or the outlet 215 may have a zero potential because they are conductively connected to the ground connection 140 .

[0026] The heating device 100 may be further configured to send a DC current 130 from the inlet 211 of the first conductive tube 220a across the first current bridge link 218a to the inlet 211 of the second conductive tube 220b. The heating device 100 may be further configured to send a DC current 130 from the outlet 215 of the first conductive tube 220a across the second current bridge link 218b to the outlet 215 of the second conductive tube 220b. The current bridge links 218a, 218b are intended to be a low resistance path compared to the connection between the inlet 211 or the outlet 215. Thus, a relatively larger portion of the DC current 130 flows through the current bridge links 218a, 218b than through the connection between the inlet 211 and the outlet 215.

[0027] In an embodiment, the heating device 100 may further include a positive conductor 124 and a negative conductor 126. In an embodiment, the positive conductor 124 electrically connects the DC current / voltage source 120 with the first conductive tube 220a. Similarly, the negative conductor 126 may electrically connect the DC current / voltage source 120 with the second conductive tube 220b.

[0028] In an embodiment, heating device 100 may be configured to send DC current 130 from DC current / voltage source 120 through positive conductor 124 to first conductive tube 220a. Additionally or alternatively, heating device 100 may be configured to send DC current 130 from second conductive tube 220b through negative conductor 126 to DC current / voltage source 120.

[0029] In embodiments, the positive conductor 124 may be electrically connected to the first conductive tube 220a at a location between the inlet 211 and the outlet 215. Similarly, in embodiments, the negative conductor 126 may be electrically connected to the second conductive tube 220b at a location between the inlet 211 and the outlet 215. In embodiments, the positive conductor 124 and the negative conductor 126 may be electrically connected approximately halfway along the length of the conductive tubes 220a, 220b. In embodiments, the positive conductor 124 and the negative conductor 126 may be electrically connected to the conductive tubes 220a, 220b at a location relatively closer to the inlet 211 than to the outlet 215, as shown in FIG. 1 . In embodiments in which the positive conductor 124 and the negative conductor 126 are electrically connected at a location along the length of the conductive tubes 220a, 220b relatively closer to the inlet 211 than to the outlet 215, more than 50% of the total electrically generated heat per conductive tube 220a, 220b may be generated in the first half of the conductive tubes 220a, 220b. In an embodiment, 50% to 95%, 50% to 90%, 50% to 85%, 50% to 80%, 50% to 75%, 50% to 70%, 50% to 65%, 50% to 60%, 50% to 55%, 55% to 95%, 55% to 90%, 55% to 85%, 55% to 80%, 55% to 75%, 55% to 70%, 55% to 65%, 55% to 60%, 60% to 95%, 60% to 90%, 60% to 85%, 60% to 80%, 60% to 75%, 60% to 70%, 60% to 65%, 65% to 95%, 65% to 90%, 65% to 85%, 65% to 80%, 65% to 75%, 65% to 70%, 70% to 95%, 70% to 90%, 70% to 85%, 70% to 80%, 70% to 75%, 75% to 95%, 75% to 90%, 75% to 85%, 75% to 80%, 80% to 95%, 80% to 90%, 80% to 85%, 85% to 95%, 85% to 90%, or 90% to 95% may be generated in the first half of the conductive tubes 220a, 220b. In an embodiment, the average heat load (total heat divided by total surface area) along the length of each conductive tube is between 10 and 150 kilowatts per square meter (kW / m 2 ), e.g., 15~150Kw / m 2 , 20~150Kw / m 2 , 25~150Kw / m 2、30~150Kw / m 2 、40~150Kw / m 2 、50~150Kw / m 2 、70~150Kw / m 2 、90~150Kw / m 2 、100~150Kw / m 2 、125~150Kw / m 2 、10~125kW / m 2 、15~125Kw / m 2 、20~125Kw / m 2 、25~125Kw / m 2 、30~125Kw / m 2 、40~125Kw / m 2 、50~125Kw / m 2 、70~125Kw / m 2 、90~125Kw / m 2 、100~125Kw / m 2 、10~100kW / m 2 、15~100Kw / m 2 、20~100Kw / m 2 、25~100Kw / m 2 、30~100Kw / m 2 、40~100Kw / m 2 、50~100Kw / m 2 、70~100Kw / m 2 、90~100Kw / m 2 、10~90kW / m 2 、15~90Kw / m 2 、20~90Kw / m 2 、25~90Kw / m 2 、30~90Kw / m 2 、40~90Kw / m 2 、50~90Kw / m 2 、70~90Kw / m 2 、10~70kW / m 2 、15~70Kw / m 2 、20~70Kw / m 2 、25~70Kw / m 2 、30~70Kw / m 2 、40~70Kw / m 2 、50~70Kw / m 2 、10~50kW / m 2, 15~50Kw / m 2 , 20~50Kw / m 2 , 25~50Kw / m 2 , 30~50Kw / m 2 , 40~50Kw / m 2 , 10 to 40kW / m 2 , 15~40Kw / m 2 , 20~40Kw / m 2 , 25~40Kw / m 2 , 30~40Kw / m 2 , 10 to 30kW / m 2 , 15~30Kw / m 2 , 20~30Kw / m 2 , 25~30Kw / m 2 , 10 to 25kW / m 2 , 15~25Kw / m 2 , 20~25Kw / m 2 , 10 to 20kW / m 2 , 15~20Kw / m 2 , or 10 to 15kW / m 2 The range is.

[0030] 2A and 2B, which are side views of the heating apparatus 100 according to one or more embodiments, further define the heating apparatus 100 according to the embodiments disclosed and described herein. As shown in FIG. 2A, ground connections 140 are electrically connected to the left and right sides of the first conductive tube 220a. Additionally, a positive conductor 124 is connected to the center of the first conductive tube 220a to provide electrical current to the first conductive tube 220a. As a result of the electrical resistance of the first conductive tube 220a, applying electrical current to the first conductive tube 220a via the positive conductor 124 increases the temperature of the first conductive tube 220a, thereby heating a first portion of the hydrocarbon fluid 202a entering the first conductive tube 220a on the left side of FIG. 2A. The first portion of the hydrocarbon fluid 202a reacts within the first conductive tube 220a to form a product stream 204.

[0031] As shown in FIG. 2B , ground connections 140 are electrically connected to the left and right sides of second conductive tube 220b. Additionally, a negative conductor 126 is connected to the center of second conductive tube 220b to provide an electrical circuit to first conductive tube 220a and positive conductor 124 shown in FIG. 2A . Referring again to FIG. 2B , as a result of the electrical resistance of second conductive tube 220b, applying an electric current through the circuit formed by positive conductor 124, first conductive tube 220a, second conductive tube 220b, and negative conductor 126 increases the temperature of second conductive tube 220b, thereby heating a second portion of hydrocarbon fluid 202b entering second conductive tube 220b on the left side of FIG. 2B . The second portion of hydrocarbon fluid 202b reacts within second conductive tube 220b to form product stream 204.

[0032] 3A and 3B, which are perspective views of a heating apparatus 100 according to one or more embodiments, further define the heating apparatus 100 according to the embodiments disclosed and described herein. As shown in FIG. 3A, a first conductive tube 220a and a second conductive tube 220b are each fluidly connected to a feed channel 210 on the left side of FIG. 3A, where a first portion (not shown) of a hydrocarbon fluid 202a enters the first conductive tube 220a and a second portion (not shown) of a hydrocarbon fluid 202b enters the second conductive tube 220b. Similarly, the first conductive tube 220a and the second conductive tube 220b are fluidly connected to a product channel 214, where a product stream 204 (not shown) exits the first conductive tube 220a and the second conductive tube 220b. A positive conductor 124 is electrically connected to the first conductive tube 220a to provide an electric current to the first conductive tube 220a, thereby increasing the temperature of the first conductive tube 220a as a result of its electrical resistance. The first current bridge link 118a and the second current bridge link 118b electrically connect the first conductive tube 220a to the second conductive tube 220b, allowing current to flow more easily between the first conductive tube 220a and the second conductive tube 220b. It should be understood that the first current bridge link 118a and the second current bridge link 118b may be present in the embodiment shown in FIGS. 2A and 2B but are not visible in the side view. Referring again to FIG. 3A, the ground connection 140 is electrically connected to the first current bridge link 118a and the second current bridge link 118b. The second conductive tube 220b is electrically connected to the negative conductor 126, thereby completing an electrical circuit between the positive conductor 124, the first conductive tube 220a, the first current bridge link 118a, the second current bridge link 118b, the second conductive tube 220b, and the negative conductor 126.

[0033] 3B, the plurality of first conductive tubes 220a and the plurality of conductive tubes 220b are each fluidly connected to a feed channel 210 on the left side of FIG. 3B, where a first portion of the hydrocarbon fluid 202a enters the plurality of first conductive tubes 220a and a second portion of the hydrocarbon fluid 202b enters the plurality of second conductive tubes 220b. Similarly, the plurality of first conductive tubes 220a and the plurality of second conductive tubes 220b are fluidly connected to a product channel 214, where the product stream 204 exits the plurality of first conductive tubes 220a and the plurality of second conductive tubes 220b. The plurality of positive conductors 124 are electrically connected to the plurality of first conductive tubes 220a to provide an electric current to the plurality of first conductive tubes 220a, thereby increasing the temperature of the plurality of first conductive tubes 220a as a result of their electrical resistance. The plurality of first current bridge links 118a and the plurality of second current bridge links 118b electrically connect the plurality of first conductive tubes 220a to the plurality of second conductive tubes 220b, thereby allowing current to flow more easily between the plurality of first conductive tubes 220a and the plurality of second conductive tubes 220b. A ground connection 140 is electrically connected to the plurality of first current bridge links 118a and the plurality of second current bridge links 118b. The plurality of second conductive tubes 220b are electrically connected to the plurality of negative conductors 126, thereby completing an electrical circuit between the plurality of positive conductors 124, the plurality of first conductive tubes 220a, the plurality of first current bridge links 118a, the plurality of second current bridge links 118b, the plurality of second conductive tubes 220b, and the plurality of negative conductors 126.

[0034] The present disclosure is also directed to a process for upgrading hydrocarbon fluids using the heating devices described herein. The process can use any of the heating devices previously described in this disclosure.

[0035] A process for upgrading a hydrocarbon fluid 202 includes introducing the hydrocarbon fluid 202 into a fluid inlet 212 of a feed channel 210 and introducing the hydrocarbon fluid 202 into a pair of conductive tubes 220a, 220b. In an embodiment, the hydrocarbon fluid 202 is 60-99 wt%, 60-95 wt%, 60-85 wt%, 60-80 wt%, 60-75 wt%, 60-70 wt%, 60-65 wt%, 65-99 wt%, 65-95 wt%, 65-85 wt%, 65-80 wt%, 65-75 wt%, 65-70 wt%, 70-99 wt%, 70-95 ... The hydrocarbon fluid 202 may comprise paraffins in an amount of 70-85 wt%, 70-80 wt%, 70-75 wt%, 75-99 wt%, 75-95 wt%, 75-85 wt%, 75-80 wt%, 80-99 wt%, 80-95 wt%, 80-85 wt%, 85-99 wt%, 85-95 wt%, 85-90 wt%, 90-95 wt%, or 95-99 wt% by weight. The hydrocarbon fluid 202 may be gaseous, liquid, or a combination of the two. In embodiments, the paraffins may comprise acyclic saturated hydrocarbons such as methane, ethane, propane, butane, pentane, hexane, or combinations thereof.

[0036] Introducing the hydrocarbon fluid 202 into the pair of conductive tubes 220a, 220b includes introducing a first portion of the hydrocarbon fluid 202a into the inlet 211 of the first conductive tube 220a and introducing a second portion of the hydrocarbon fluid 202b into the inlet 211 of the second conductive tube 220b. It should be understood that similar flows occur with additional pairs of conductive tubes. In embodiments, the process may include additional pairs of conductive tubes as described above.

[0037] The process further includes applying a DC current 130 to the first conductive tube 220a to heat a first portion of the hydrocarbon fluid 202a within the first conductive tube 220a to a reaction temperature to form a first product stream 204. The process further includes applying a DC current 130 to the second conductive tube 220b to heat a second portion of the hydrocarbon fluid 202b within the second conductive tube 220b to a reaction temperature to form a second product stream 204. In an embodiment, heating the first portion of hydrocarbon fluid 202a and heating the second portion of hydrocarbon fluid 202b includes heating to 600°C to 900°C, 600°C to 850°C, 600°C to 800°C, 600°C to 750°C, 600°C to 700°C, 600°C to 650°C, 650°C to 900°C, 650°C to 850°C, 650°C to 800°C, 650°C to 750°C, 650°C to 700°C, 700°C to 900°C, 700°C to 850°C, 700°C to 800°C, 700°C to 750°C, 750°C to 900°C, 750°C to 850°C, 750°C to 800°C, 800°C to 900°C, 800°C to 850°C, or 850°C to 900°C.

[0038] In embodiments, the process may further include sending DC current 130 from DC current / voltage source 120 through positive conductor 124 to first conductive tube 220a, and sending DC current 130 from first conductive tube 220a to second conductive tube 220b. The process may further include sending DC current 130 from second conductive tube 220b through negative conductor 126 to DC current / voltage source 120.

[0039] In an embodiment, applying DC current 130 to conductive tube 220 may provide a first half of conductive tube 220 with a total heat load of greater than 50%, between 50% and 95%, between 50% and 85%, between 50% and 80%, between 50% and 75%, between 50% and 70%, between 50% and 6 ... % to 95%, 60% to 85%, 60% to 80%, 60% to 75%, 60% to 70%, 60% to 65%, 65% to 95%, 65% to 85%, 65% to 80%, 65% to 75%, 65% to 70%, 70% to 95%, 70% to 85%, 70% to 80%, 70% to 75%, 75% to 95%, 75% to 85%, 75% to 80%, 80% to 95%, 80% to 85%, 85% to 95%, 85% to 90%, or 90% to 95%. Specifically, in embodiments, applying DC current 130 to first conductive tube 220a provides greater than 50% of the total heat load to the first half of first conductive tube 220a. Similarly, in embodiments, application of DC current to the second conductive tube 220b may result in a first half of the second conductive tube 220b receiving a total heat load of greater than 50%, 50% to 95%, 50% to 85%, 50% to 80%, 50% to 75%, 50% to 70%, 50% to 65%, 50% to 60%, 50% to 55%, 55% to 95%, 55% to 85%, 55% to 80%, 55% to 75%, 55% to 70%, 55% to 65%, 55% to 60%, Available options include 60% to 95%, 60% to 85%, 60% to 80%, 60% to 75%, 60% to 70%, 60% to 65%, 65% to 95%, 65% to 85%, 65% to 80%, 65% to 75%, 65% to 70%, 70% to 95%, 70% to 85%, 70% to 80%, 70% to 75%, 75% to 95%, 75% to 85%, 75% to 80%, 80% to 95%, 80% to 85%, 85% to 95%, 85% to 90%, or 90% to 95%.

[0040] The process further includes introducing a first product stream 204 into product channel 214 through outlet 215 of first conductive tube 220a and introducing a second product stream 204 into product channel 214 through outlet 215 of second conductive tube 220b. First and second product streams 204 may 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 embodiments, first product stream 204 and second product stream 204 may include greater than 20 wt%, greater than 25 wt%, greater than 30 wt%, greater than 35 wt%, or greater than 40 wt% olefins. In embodiments, the first product stream 204 and the second product stream 204 may be 20-100 wt%, 20-95 wt%, 20-90 wt%, 20-85 wt%, 20-80 wt%, 20-75 wt%, 20-70 wt%, 20-65 wt%, 20-60 wt%, 20-55 wt%, 20-50 wt%, 20-45 wt%, 20-40 wt%, 20-35 wt%, 20-30 wt% , 20~25% by weight, 25~100% by weight, 25~95% by weight, 25~90% by weight, 25~85% by weight, 25~80% by weight, 25~75% by weight, 25~70% by weight, 25~65% by weight, 25~60wt%, 25~55wt%, 25~50wt%, 25~45wt%, 25~40wt%, 25~35wt%, 25~30wt%, 30~100wt%, 30~95wt%, 30 ~90wt%, 30~85wt%, 30~80wt%, 30~75wt%, 30~70wt%, 30~65wt%, 30~60wt%, 30~55wt%, 30~50wt%, 30~4 5% by weight, 30~40% by weight, 30~35% by weight, 35~100% by weight, 35~95% by weight, 35~90% by weight, 35~85% by weight, 35~80% by weight, 35~75% by weight, 35~70 Weight%, 35-65% by weight, 35-60% by weight, 35-55% by weight, 35-50% by weight, 35-45% by weight, 35-40% by weight, 40-100% by weight, 40-95% by weight, 40-90% by weight Amount%, 40-85 wt%, 40-80 wt%, 40-75 wt%, 40-70 wt%, 40-65 wt%, 40-60 wt%, 40-55 wt%, 40-50 wt%, 40-45 wt%,45~100wt%, 45~95wt%, 45~90wt%, 45~85wt%, 45~80wt%, 45~75wt%, 45~70wt%, 45~65wt%, 45~6 0% by weight, 45~55% by weight, 45~50% by weight, 50~100% by weight, 50~95% by weight, 50~90% by weight, 50~85% by weight, 50~80% by weight, 50~75% by weight , 50~70% by weight, 50~65% by weight, 50~60% by weight, 50~55% by weight, 55~100% by weight, 55~95% by weight, 55~90% by weight, 55~85% by weight, 55~ 80% by weight, 55~75% by weight, 55~70% by weight, 55~65% by weight, 55~60% by weight, 60~100% by weight, 60~95% by weight, 60~90% by weight, 60~85% by weight , 60~80% by weight, 60~75% by weight, 60~70% by weight, 60~65% by weight, 65~100% by weight, 65~95% by weight, 65~90% by weight, 65~85% by weight, 65~ 80% by weight, 65~75% by weight, 65~70% by weight, 70~100% by weight, 70~95% by weight, 70~90% by weight, 70~85% by weight, 70~80% by weight, 70~75% by weight %, 75 to 100% by weight, 75 to 95% by weight, 75 to 90% by weight, 75 to 85% by weight, 75 to 80% by weight, 80 to 100% by weight, 80 to 95% by weight, 80 to 90% by weight, 80 to 85% by weight, 85 to 100% by weight, 85 to 95% by weight, 85 to 90% by weight, 90 to 100% by weight, 90 to 95% by weight, or 95 to 100% by weight of olefin.

[0041] In embodiments, one or more of the conductive tubes 220 of the conductive tube pair 220a, 220b may have multiple heating zones, each operating at a different temperature. Referring now to FIG. 4A , the conductive tube 220 includes an inlet 211 through which the hydrocarbon fluid 202 enters the conductive tube 220 and an outlet 215 through which the product stream 204 exits the conductive tube. Disposed between the inlet 211 of the conductive tube 220 and the outlet 215 of the conductive tube 220 is a conductor that conducts electrical current to and from the conductive tube 220. It should be understood that the conductor may be either the positive conductor 124 or the negative conductor 126 discussed above, labeled 124 / 126 in FIG. 4A . In the embodiment shown in FIG. 4A , the first heating zone 221 is disposed to the left of the conductor 124 / 126, and the second heating zone 222 is disposed to the right of the conductor 124 / 126. The temperature within the first heating zone 221 is different from the temperature within the second heating zone 222. The temperature difference between the first heating zone 221 and the second heating zone 222 may be achieved by having different resistances in the first heating zone 221 and the second heating zone 222. For example, the portion of the conductive tube 220 that includes the first heating zone 221 may be made of a material having a different resistivity than the material of the portion of the conductive tube 220 that includes the second heating zone 222. As another example, the portion of the conductive tube 220 that includes the first heating zone 221 may have a different cross-section or wall thickness than the portion of the conductive tube 220 that includes the second heating zone 222. In this manner, the temperature in the first heating zone 221 may be higher or lower than the temperature in the second heating zone by transmitting an electric current through the conductors 124 / 126.

[0042] Having multiple heating zones 221, 222 within the electrically conductive tube 220 may be desirable when the process for converting the hydrocarbon fluid 202 to the product stream 204 requires rapidly heating the hydrocarbon fluid 202 to a reaction temperature and then maintaining the temperature of the hydrocarbon fluid 202 at the reaction temperature for a period of time to complete the reaction of the hydrocarbon fluid 202 into the product stream 204. In such situations, it may be desirable to have the temperature of the first heating zone 221 higher than the temperature of the second heating zone 222. This temperature difference between the first heating zone 221 and the second heating zone 222 may be achieved by constructing the first heating zone 221 from a material that has a lower electrical resistivity than the material from which the second heating zone 222 is constructed. Additionally, the first heating zone 221 may have a cross-section or wall thickness that provides a higher overall electrical resistivity in the first heating zone 221 than in the second heating zone 222. It should also be appreciated that a temperature gradient can be provided within the first heating zone 221 itself by using a varying cross-section or wall thickness within the first heating zone 221. Similarly, a temperature gradient may be provided within the second heating zone 222 itself by using a varying cross section or wall thickness within the second heating zone 222.

[0043] As described above, the temperature difference between the first and second heating zones 221 and 222, as well as the temperature gradient within the first and second heating zones 221 and 222, allows for fine tuning and better control of the heating within the electrically conductive tubes 220. For example, a heating program for producing a desired product stream 204 from a given hydrocarbon fluid 202 can be obtained using reaction kinetics and simulations as would be known by one of ordinary skill in the art, and then an electrically heated reactor using pairs of electrically conductive tubes 220 as disclosed and described herein can be fabricated using various materials for the tubes, various tube cross sections, and various tube wall thicknesses to best approximate the heating program simulated using reaction kinetics. Furthermore, controlling the temperature of the tubes using electrical current is easier than current multiple combustion burners, which can operate at higher or lower temperatures depending on gas flow, walls, parts, proximity to other burners, etc.

[0044] 4A-5B illustrate two possible geometries for the conductive tube 220 according to embodiments disclosed and described herein. It should be understood that the geometries illustrated in FIGS. 4A-5B are merely exemplary and are not intended to limit the present disclosure. Many other geometries may be utilized within the scope of the present disclosure. As shown in FIGS. 4A-5B, each conductive tube 220 may include straight and / or curved tubes, such as a U-shaped tube, a W-shaped tube, multiple U-shaped tubes, and multiple W-shaped tubes. FIG. 4A illustrates a U-shaped tube having a first heating zone 221 on the left side of the conductive tube 220 and a second heating zone 222 on the right side of the conductive tube 220. FIG. 4B illustrates a double U-shaped tube having two tubes 221a and 221b within the first heating zone 221. The use of double U-shaped tubes allows the volume of hydrocarbon fluid 202 in the first heating zone 221 to be separated into two tubes 221a and 221b, which can increase the rate at which the hydrocarbon fluid 202 is heated in the first heating zone 221 by increasing the contact area between the hydrocarbon fluid 202 and the heated tube walls.

[0045] FIG. 5A illustrates a W-shaped conductive tube 220 in which the total volume of hydrocarbon fluid 202 within the W-shaped conductive tube 220 is greater than the volume of hydrocarbon fluid 202 within the U-shaped conductive tube 220 shown in FIG. 4A. Accordingly, the first heating zone 221 of the W-shaped conductive tube 220 shown in FIG. 5A also has a larger volume than the first heating zone 221 of the U-shaped conductive tube 220 shown in FIG. 4A. FIG. 5B illustrates a double W-shaped conductive tube 220 in which the volume of hydrocarbon fluid 202 within the first heating zone 221 is separated into two tubes 221 a and 221 b. Use of the double W-shaped conductive tube 220 allows the volume of hydrocarbon fluid 202 within the first heating zone 221 to be separated into two tubes 221 a and 221 b, which increases the contact area between the hydrocarbon fluid 202 and the heated tube walls, thereby increasing the rate at which the hydrocarbon fluid 202 is heated within the first heating zone 221. 4A-5B show how the conductive tubes can be customized to fit a simulated reaction program based on reaction kinetics and simulation.

[0046] By using the configurations disclosed above, it is possible to achieve greater than 50% of the heat generated electrically, e.g., 50% to 85% of the heat generated electrically, 55% to 85% of the heat generated electrically, 60% to 85% of the heat generated electrically, 65% to 85% of the heat generated electrically, 70% to 85% of the heat generated electrically, 75% to 85% of the heat generated electrically, 80% to 85% of the heat generated electrically, 55% to 80% of the heat generated electrically, 60% to 80% of the heat generated electrically, 65% to 80% of the heat generated electrically, 70% to 80% of the heat generated electrically, 75% to 80% of the heat generated electrically, 55% to 75% of the heat generated electrically, 60% to 75% of the heat generated electrically, 65% to 75% of the heat generated electrically, 70% to 75% of the heat generated electrically, 55% to 70% of the heat generated electrically, 60% to 70% of the heat generated electrically, 65% to 70% of the heat generated electrically, 55% to 65% of the heat generated electrically, 60% to 65% of the heat generated electrically, or 55% to 60% of the heat generated electrically.

[0047] It should be understood that each conductive tube 220a, 220b in a pair of conductive tubes 220 can have an individual first heating zone 221 and a second heating zone 222, regardless of the number of pairs of conductive tubes. The first heating zone 221 and second heating zone 222 in each conductive tube 220a and 220b in a pair of conductive tubes 220 can be individually designed and may be the same as or different from any other first heating zone 221 and second heating zone 222 in any other conductive tube 220a and 220b in the pair of conductive tubes 220. [Example]

[0048] In accordance with the above-described embodiment, a process was calculated for upgrading hydrocarbons using a cracking conduit with a single constant heat flux along the entire length of the conduit and an electrically conductive tube with dual heating zones consisting of a higher heating at the inlet section of the conduit and a zone of the conduit immediately thereafter with a lower heat flux.

[0049] The single-heat zone cracking conduit had an inner diameter of 3 inches, a wall thickness of 0.355 inches, a length of 40.5 m, and an electrical resistance of 1.494 μΩ-m at 900°C. Temperature-dependent electrical resistance was assumed. The conduit was connected to a DC potential of 132 V at one end of the tube path and 0 V at the other end of the path. The total current (Io) was 4892 amps. This configuration has a uniform heat generation rate throughout the conduit. A hydrocarbon fluid was then flowed through the conventional cracking conduit at a flow rate of 793.7 kg / hr and an inlet temperature of 675°C. The hydrocarbon fluid contained 80 wt% ethane and 20 wt% water vapor.

[0050] The conductive tube with dual-zone heat flux had an inner diameter of 3 inches, a length of 40.5 m, and an electrical resistance of 1.494 μΩ-m at 900°C. Temperature-dependent electrical resistance was assumed. A DC potential difference of 122 V was applied to the pair of electrically connected tubes in series, located 17.5 m from the inlet. The wall thickness was 0.5 inches for the first conductive tube and 0.3 inches for the remainder of the conductive tube. A hydrocarbon fluid was then flowed through a conventional cracking conduit at a flow rate of 793.7 kg / hr and an inlet temperature of 675°C. The hydrocarbon fluid contained 80 wt% ethane and 20 wt% water vapor. The potential field, DC current, process flow, and cracking reaction were simulated using a Computational Fluid Dynamics (CFD) model in Fluent V.19.4. The electrical heat generated in the first 50% of the conductive tube volume accounted for 73% of the total heat content along the length of the conductive tube. The calculated temperature and pressure fields were then applied to a one-dimensional kinetic model to further confirm the decomposition performance.

[0051] Figure 6 is a graphical representation of ethylene yield versus cracking for a simulated system based on reaction kinetics. It illustrates how yield varies with cracking temperature achieved by the system disclosed and described herein at a constant hydrocarbon residence time. Specifically, curve 1 shows ethylene yield, curve 2 shows CH selectivity, and curve 3 shows CH selectivity. For the example described above, the asterisks in Figure 6 highlight the inflection point of curve 1 at maximum ethylene yield and the corresponding preferred reaction temperature. In the summary of the results of this example below, it is shown that a heat load configuration and potential configuration within the conductive tube, a preferred reaction temperature, and higher process yields are achieved.

[0052] The results are summarized in Table 1 below and in Figures 7 and 8. The process pressure drop across the length of the conduit was approximately 7.5 pounds per square inch differential (psid) for both the single-heated-zone cracking conduit and the dual-heated-zone conductive tube. Figure 7 compares predicted process gas temperature profiles, with curve 1 being the single-heated-zone cracking conduit and curve 2 being the dual-heated-zone (example of multiple-heated zone) conductive tube of the present disclosure, the latter showing the process gas temperature closest to the preferred reaction temperature. Figure 8 compares the ethylene dry mass fraction along the length of the conduit, with curve 1 being the single-heated-zone cracking conduit and curve 2 being the dual-heated-zone conductive tube of the present disclosure. The dual-heated-zone conductive tube was observed to increase the temperature of the hydrocarbon fluid more rapidly than the single-zone cracking conduit and then maintain the temperature of the hydrocarbon fluid within a narrow range after the initial heating. As shown in Table 1 below, it was determined that the dual-zone conductive tube provided an effluent ethylene mass fraction of 52.8 wt. % (dry) and the single-zone cracking conduit provided an effluent ethylene mass fraction of 49.2 wt. % (dry).

[0053] [Table 1]

[0054] It will be apparent to those skilled in the art that various modifications can be made to the described embodiments without departing from the spirit and scope of the claimed subject matter. Thus, it is intended that the present specification cover modifications and variations of the described embodiments provided that such modifications and variations come within the scope of the appended claims and their equivalents.

Claims

1. 1. A process for upgrading a hydrocarbon fluid, comprising: introducing the hydrocarbon fluid into a fluid inlet of a feed channel; introducing a first portion of the hydrocarbon fluid into an inlet of a first conductive tube; introducing a second portion of the hydrocarbon fluid into an inlet of a second conductive tube; applying a DC current to the first conductive tube to heat the first portion of the hydrocarbon fluid within the first conductive tube to a first reaction temperature to form a first product stream; applying a DC current to the second conductive tube to heat the second portion of the hydrocarbon fluid within the second conductive tube to a second reaction temperature to form a second product stream; introducing the first product stream into a product channel through an outlet of the first conductive tube; and introducing the second product stream into the product channel through an outlet of the second conductive tube.

2. 10. The process of claim 1, wherein the first conductive tube and the second conductive tube form a conductive tube pair, and the process includes an additional conductive tube pair.

3. The process of claim 2, wherein the process comprises 2 to 100 pairs of conductive tubes.

4. 10. The process of claim 1, wherein the feed channel and the product channel are grounded.

5. sending a DC current from the DC current / voltage source through the positive conductor to the first conductive tube; The DC current is from the inlet of the first conductive tube over a first current bridge link to the inlet of the second conductive tube; from the outlet of the first conductive tube over a second current bridge link to the outlet of the second conductive tube; or to both, The DC current is from the inlet of the first conductive tube across the feed channel to the inlet of the second conductive tube; from the outlet of the first conductive tube across the product channel to the outlet of the second conductive tube; or to both, 10. The process of claim 1, further comprising: sending a DC current from the second conductive tube through a negative conductor to the DC current voltage source.

6. 6. The process of claim 5, wherein the positive conductor is electrically connected to a location of the first conductive tube between the inlet and the outlet, and the negative conductor is electrically connected to a location of the second conductive tube between the inlet and the outlet.

7. 6. The process of claim 5, wherein the first conductive tube has the inlet fluidly connected to the feed channel and the outlet fluidly connected to the product channel, the second conductive tube has the inlet fluidly connected to the feed channel and the outlet fluidly connected to the product channel, the inlet of the first conductive tube and the inlet of the second conductive tube each having a zero potential, and the outlet of the first conductive tube and the outlet of the second conductive tube each having a zero potential.

8. 10. The process of claim 1, wherein the first conductive tube and the second conductive tube have an electrical resistivity at 900° C. of 1.0 μΩ·m to 4.0 μΩ·m.

9. 10. The process of claim 1, wherein the first conductive tube and the second conductive tube each have an inner diameter of 1 to 6 inches, a wall thickness of 0.1 to 1.5 inches, and a length of 10 to 60 meters.

10. 10. The process of claim 1, wherein the wall thickness of the first and second conductive tubes varies over the length of each of the first and second conductive tubes.

11. 2. The process of claim 1, wherein the first conductive tube and the second conductive tube form a conductive tube pair, and the electrical resistance of the conductive tube pair varies over the length of the conductive tube pair.

12. 10. The process of claim 1, wherein heating the first portion of the hydrocarbon fluid and heating the second portion of the hydrocarbon fluid comprises heating the first portion of the hydrocarbon fluid and the second portion of the hydrocarbon fluid to between 600°C and 900°C.

13. 10. The process of claim 1, wherein the hydrocarbon fluid comprises 60 to 99 wt. % paraffins and the first and second product streams comprise greater than 40 wt. % olefins.

14. applying a DC current to the first conductive tube to provide a total heat load to the first conductive tube, with greater than 50% of the total heat load being provided to a first half of the first conductive tube; 2. The process of claim 1, wherein applying a DC current to the second conductive tube provides a total heat load to the second conductive tube, and more than 50% of the total heat load is provided to a first half of the second conductive tube.

15. applying a DC current to the first conductive tube to provide a total heat load to the first conductive tube, wherein 60% to 85% of the total heat load is provided to a first half of the first conductive tube; 15. The process of any one of claims 1 to 14, wherein applying a DC current to the second conductive tube provides a total heat load to the second conductive tube, and 60% to 85% of the total heat load is provided to a first half of the second conductive tube.

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