Modular reactor configuration for the production of chemicals with electrical heating to carry out the reaction

Abstract

A novel modular reactor configuration is provided that utilizes resistive heating elements that pass through a reaction zone of a reactor module and conduct electricity, thereby providing resistive heating within the reaction zone to promote conversion of reactants to products when present within the reaction zone. The resistive heating elements may be configured as multiple wires, multiple plates, wire mesh, gauze, and / or metal monoliths.

Description

[Technical Field]

[0001] The present invention relates to a modular reactor configuration comprising at least one electric heating element and a method for carrying out a process at high temperature comprising introducing at least one gas reactant into the reactor configuration. The reactor and method are useful in many industrial-scale high-temperature gas conversion and heating technologies. [Background technology]

[0002] Global warming and the need to reduce global carbon dioxide emissions are currently high on the political agenda. Indeed, solving the problem of global warming is considered the most important challenge facing humanity in the 21st century. The Earth system's capacity to absorb greenhouse gas emissions has already been reached, and under the Paris Climate Agreement, current emissions must be completely halted by around 2070. Achieving these reductions requires, at a minimum, a major restructuring of industry away from traditional CO2-producing energy carriers. This decarbonization of the energy system requires an energy transition away from traditional fossil fuels such as oil, natural gas, and coal. Timely implementation of the energy transition requires multiple parallel approaches. For example, energy conservation and energy efficiency improvements play a role, but so do efforts to electrify transportation and industrial processes. After a transition period, renewable energy generation is expected to comprise the majority of global energy generation, which will consist largely of electricity.

[0003] While there are various small, dispersed sources of CO2 emissions (e.g., vehicles, humans / animals, etc., which contribute significant cumulative amounts), the primary sources are power plants or chemical manufacturing plants, where fossil fuels are traditionally burned in furnaces to generate electricity or provide the heat needed to drive endothermic reactions. For example, current ethane cracking technology releases approximately 1.2 moles of CO2 into the atmosphere for every mole of ethylene produced. In other words, a world-class ethane cracker produces one million tons per annum (MTA) of ethylene and releases roughly 1,800 MTA of CO2 into the atmosphere. Similar amounts of CO2 are emitted from other endothermic processes, such as the thermal cracking or decomposition of hydrocarbons (e.g., ethane, propane, or naphtha) into higher-value hydrocarbon products (such as ethylene, propylene, and other olefins); the reverse water-gas shift (RWGS) reaction, which uses hydrogen to convert CO2 to CO; dry methane reforming (DMR) and steam methane reforming (SMR) reactions to produce synthesis gas; the thermal cracking of methane to produce high-quality hydrogen and carbon; and various adsorption-desorption processes.

[0004] Because the cost of renewable electricity is already low in certain parts of the world, technologies using electrically heated reactors and equipment could be attractive for replacing conventional hydrocarbon-fired heated reactors and heavy-duty heating operations. Projected electricity prices and CO2 costs will further increase the economic attractiveness of these reactors.

[0005] Electricity is the highest grade of available energy. When designing efficient industrial processes to convert electrical energy into chemical energy, several options are considered. These options are electrochemical, low-temperature plasma, high-temperature plasma, or thermal. In small-scale laboratory environments, electrical heating has already been applied to many types of processes focusing on chemical and material aspects. However, when these options are considered to design chemical (conversion) technologies on an industrial scale, such as gas conversion, each of these options involves specific complexities related to the design and scale-up of reactor configurations and material requirements. This is especially true when the chemical conversion process is highly endothermic due to the high heat flux and temperature levels required. There is a need in industry for electrification technologies suitable for endothermic chemical reactions and heating technologies on an industrial scale.

[0006] Prior art systems used for these and other endothermic reactions are typically based on the internal flow of reactant gases through empty or catalyst-filled tubes, with the required heat supplied through the tube walls by combustion of fossil fuels in a combustion furnace or by direct heat transfer through a heat exchanger. For processes with high heat flux requirements, the required heat is obtained through a combustion furnace, consisting of a closed, refractory space with a fuel burner that provides heat via radiative transfer to the reactor tube walls. Therefore, in addition to CO2 emissions, prior art technologies for endothermic processes based on burning fossil fuels in a furnace present several other drawbacks, such as lower reactor thermal efficiency (as low as 30–40%) and longer start-up and shutdown times (on the order of tens of hours to days). While additional process integration (such as utilizing the heat capacity of the outlet stream) can result in an eventual increase in thermal efficiency, these other deficiencies still exist.

[0007] Because the capital cost of a combustion furnace decreases with scale, the commercial size of prior art systems is large, sacrificing flexibility in equipment turndown. As a result of the large size and unique nature of these prior art systems, the entire furnace unit requires periodic shutdown and cooling to mitigate operational and / or safety issues associated with continuous operation. For example, standard operation of these prior art systems results in the accumulation of coke on the inner tube walls, which commonly occurs when the furnace is operated at high temperatures. Coke accumulation on the reactor walls causes a reduction in heat flux (i.e., heat transfer from solids to gas), resulting in lower conversion rates and increased pressure drop over time. This accumulation also increases the outer tube wall temperature, which can potentially lead to tube failure (or shorten the time to failure) due to metallurgical overheating and thermal stresses. Furthermore, heat flux may not be uniform depending on the number of fuel burners, necessitating the use of a larger number of burners and optimizing their location for spatial uniformity in heat flux.

[0008] US Patent No. 2016288074 describes a furnace for steam reforming a feed stream containing hydrocarbons, preferably methane, comprising a combustion chamber, a plurality of reactor tubes containing a catalyst and arranged in the combustion chamber for passing the feed stream through the reactor tubes, and at least one burner configured to burn a combustion fuel in the combustion chamber to heat the reactor tubes. In addition, at least one voltage source is provided, which is connected to the plurality of reactor tubes in each case so that an electric current can be generated in the reactor tubes to heat the feedstock.

[0009] U.S. Patent No. 2017106360 describes how endothermic reactions can be controlled in a truly isothermal manner using external heat input applied directly to the solid catalyst surface itself, rather than by indirect means external to the actual catalyst material. This heat source can be supplied uniformly and isothermally to the catalytically active sites by conduction alone using electrical resistance heating of the catalyst material itself, or by an electrical resistance heating element with active catalyst material coated directly on its surface. By using conduction alone as the mode of heat transfer to the catalyst sites, the non-uniform modes of radiation and convection are avoided, allowing a uniform, isothermal chemical reaction to occur. Summary of the Invention

[0010] Prior art approaches have their own challenges, capabilities, and / or are based on combining combustion heating with linear electric heating. Thus, there remains a need for more and other options for electric heating technologies that can be applied to, for example, large-scale chemical processes.

[0011] The present disclosure provides a solution to that need. The present disclosure relates to an industrial-scale, electrified gas conversion technology that achieves high process efficiency, is relatively simple, and has low overall cost.

[0012] It has been discovered that the limitations present in prior art systems can be overcome by the use of a novel reactor configuration in which the use of a combustion furnace to provide the necessary heat to the endothermic process is replaced by electrical heating (preferably using renewable electricity). Such a novel reactor configuration not only mitigates the shortcomings of prior art systems, but also includes additional advantages, including modular flexibility and ease of scalability.

[0013] Thus, the present disclosure relates to a novel reactor system in which heating elements are positioned so that heat delivery to the gases is uniform and can be adjusted based on gas flow rate, reaction enthalpy, and reaction kinetics.

[0014] In one embodiment, a modular reactor system for conducting an endothermic reaction comprises at least one module, each module further comprising: (a) a plurality of wall sections positioned to surround a heating zone inside a channel configured to allow fluid to flow through the heating zone; (b) a power source; and (c) at least one resistive heating element passing through the reaction zone, the resistive heating element being mechanically connected to the wall sections and electrically connected to the power source. In some embodiments, the at least one resistive heating element is electrically insulated from the wall sections. In some embodiments, the reactor system is configured to allow flow of a fluid containing one or more reactants. In some embodiments, the heating zone is suitable for converting reactants to products when present in the fluid. In some embodiments, the resistive heating element of each module is configured to generate resistive heating within the reaction zone such that the temperature of the reaction zone can be adjusted to a required reaction temperature range. In some embodiments, the at least one resistive heating element comprises a component selected from the group consisting of a plurality of wires, a plurality of plates, a wire mesh, gauze, and a metal monolith.

[0015] The features and advantages of the present invention will be apparent to those skilled in the art, and many modifications may be made by those skilled in the art, all of which are within the spirit and scope of the present invention. [Brief explanation of the drawings]

[0016] A more detailed description of the invention, briefly summarized above, can be had by reference to the embodiments of the invention as illustrated in the accompanying drawings and described herein. It should be noted, however, that the accompanying drawings illustrate only some embodiments of the invention and therefore should not be considered as limiting the scope of the invention, as other equally effective embodiments may be recognized. [Figure 1] 1A-1D show isometric views of different types of heating element configurations disclosed herein, including representative examples of (a) parallel wire, (b) parallel plate, (c) metal monolith, and (d) wire mesh / gauze reactor configurations. [Figure 2] 1A-1C show isometric views of (a) a single modular unit of the disclosed reactor system, (b) a single module with multiple modular units, and (c) large-scale parallel and series arrangements of multiple modules. [Figure 3] 1 shows the results of thermodynamic calculations for ethane cracking, SMR, and DMR at adiabatic isothermal and electrification conditions, including (a) equilibrium conversion vs. inlet fluid temperature for ethane cracking, (b) conversion vs. space time for ethane cracking with a feed of 1100 K (approximately 827° C.), (c) equilibrium conversion vs. inlet fluid temperature for SMR, (d) conversion vs. space time for SMR with a feed of 1000 K (approximately 727° C.), and (e) equilibrium conversion vs. inlet fluid temperature for DMR, (b) conversion vs. space time for DMR with a feed of 1100 K (approximately 827° C.). [Figure 4] 1 is a graph showing reaction time scale versus conversion at various fluid temperatures for ethane cracking. [Figure 5] 1 is a graph of conversion versus space time for ethane cracking at various process temperatures for certain parallel wire configurations disclosed herein. [Figure 6] 1A-1C show various views of a single parallel wire module. [Figure 7] 1 is a graph showing the conversion, solid temperature, and fluid temperature profiles for ethane cracking using a particular parallel wire configuration disclosed herein, including (a) the time profile at the outlet and (b) the spatial profile at t=10 s. DETAILED DESCRIPTION OF THE INVENTION

[0017] To replace industrial-scale gas-fired heating with electric heating, several heating options can be considered. Such electric furnaces, including those described herein, have the advantage of generating heat without relying on a specific fuel source due to the fungibility of electricity. The invention disclosed herein has the additional advantage of helping to achieve carbon neutrality goals by having the option to use electricity provided by renewable fuels. Advantages of specific embodiments are further described below.

[0018] According to some embodiments of the present invention, various novel reactor configurations (illustrated in FIG. 1 ) enable endothermic reactions to produce value-added chemicals, where the necessary heat is provided using electrical power. The systems disclosed herein facilitate lower CO2 emissions than conventional systems, or even emission-free operation, when utilizing electricity generated via renewable sources. Representative configurations of certain embodiments are shown in FIG. 1 , including configurations based on modular units consisting of (1) parallel wire ("PW"), (2) parallel plate ("PP"), (3) short metallic monolith ("SM") with low aspect ratio, and (4) wire mesh or gauze reactors. These configurations are suitable for a wide range of homogeneous gas-phase endothermic reactions, including, but not limited to, the thermal cracking or cracking of ethane, naphtha, or other hydrocarbons. In some embodiments, the heating elements (e.g., wires or plates, etc.) can also be coated with a thin layer of catalytic material to promote other endothermic reactions, such as reverse water gas shift (RWGS), dry methane reforming (DMR), and steam methane reforming (SMR) reactions. Certain configurations can also be used with or without catalysts for these and other similar endothermic reactions, including methane pyrolysis, ammonia decomposition, and various adsorption-desorption processes. Additionally, some embodiments may include modular units, further allowing for ease and flexibility in scale-up.

[0019] The term reactor configuration as used herein should be understood to include any industrial facility suitable for industrial scale reactions and process heating.

[0020] Conventional furnace-based heating for reactor units is primarily based on radiative heat transfer, which is described by the Stefan-Boltzmann law for radiation. A first-principles calculation based on the Stefan-Boltzmann law shows that a heating element (with an exhaust rate of 0.4 and a temperature of 1065°C) delivers 22 kW / m to a reactor tube at 950°C. -2 However, the actual heat transfer mechanisms are much more complex than direct radiation alone. The first direct radiation mechanism involves the radiation of heat from the heating elements to the reactor tubes. The second radiator is in the form of the hot face wall of the furnace. The hot face wall can then be heated by an electric heating element. The third heat transfer mechanism occurs through (natural) convection. The gases in the furnace rise near the heating elements and fall near the reactor tubes. The fourth heat transfer mechanism occurs through the radiation of the heated gases in the furnace. Its relatively small contribution depends on the selected gas atmosphere.

[0021] In contrast to the conventional furnace-based heating described above, in the proposed configuration, heat transfer is based on resistive heating, where heat is transferred directly from the electric heating elements to the reactant / product mixture via conduction and radiation.

[0022] 1(a) and 1(b) illustrate PW and PP configuration embodiments, respectively, of the novel reactor configuration of the present disclosure, which include a pair of wall sections 100 electrically connected to a power source 102. In FIG. 1(a), the PW configuration includes a set of parallel wires 104 spanning the zone between the two wall sections 100. In this embodiment, the parallel wires 104 function as a heating element via resistance heating using electricity provided by the power source 102. Alternatively, in FIG. 1(b), the PP configuration includes a set of parallel plates 106 that also function as a heating element via resistance heating using electricity provided by the power source 102. Similarly, FIGS. 1(c) and 1(d) illustrate SM and wire mesh configurations, respectively, of the novel reactor configuration of the present disclosure, which also includes a power source 102. In FIG. 1(c), the SM configuration includes a metal monolith 108 electrically connected to the power source 102, such that the metal monolith 108 functions as a heating element via resistance heating using electricity provided by the power source 102. In FIG. 1(d), the wire mesh configuration includes a wire mesh 110 electrically connected to a power source 102 such that the wire mesh 110 functions as a heating element via resistive heating utilizing electricity provided by the power source 102.

[0023] In each of the four embodiments shown in FIG. 1 , the gas flows through the heating element, making direct contact with it and conducting heat from the heating element to the gas system. Similarly, direct radiative heat transfer from the heating element to the gas system occurs due to the temperature difference between the heating element and the gas system. The greater the temperature difference, the more heat is transferred via radiation. Direct heat transfer from the heating element to the gas system is utilized in the gas conversion process with minimal heat loss, resulting in higher heating efficiency compared to the conventional furnace-based configurations described above. The heat and mass transfer due to reaction / heating in the proposed reactor configurations are described by species and energy balance equations:

[0024] Several options for providing electric heat to the process are available and may be considered in accordance with this disclosure.

[0025] Many different types of electrical resistance heating elements exist, each with its own specific application purpose. In some embodiments of the disclosed configurations, moderately high temperatures can be achieved, for example, through mineral-insulated wire technology. In some configurations, at least one electrical heating element comprises a NiCr, NiCu, NiCrFe, MnNiCu, CrAlSiCFe, NiCoMnSiFe, NiAlTi, SiC, MoSi2, or FeCrAl-based resistance heating element. Additional materials can be used to construct electrical heating elements for the disclosed systems based on the needs and parameters of a particular embodiment.

[0026] In the reactor configurations disclosed herein, nickel-chromium (NiCr) heating elements may be used, as used in many industrial furnaces and household appliances. This material is robust, repairable (weldable), and available in various grades at moderate cost. However, the use of NiCr is limited to a maximum operating temperature of approximately 1100°C due to heating element life considerations.

[0027] Another option for use in the reactor configuration and high-temperature applications of the present disclosure is silicon carbide (SiC) heating elements. SiC heating elements can achieve temperatures up to 1600°C and are commercially available in diameters up to 55 mm. This allows for the design of modules with larger diameters and higher heating loads per element. Additionally, the cost of SiC heating elements is relatively low.

[0028] Yet another option for use in the disclosed reactor configurations and high-temperature applications is molybdenum disilicide (MoSi2) elements, which have the ability to resist oxidation at high temperatures. This is due to the formation of a thin layer of quartz glass on the surface. A slightly oxidizing atmosphere (>200 ppm O2) is required to maintain a protective layer on the elements. The material becomes ductile at temperatures above 1200°C but becomes brittle below this temperature. After operation, the elements become very brittle at low temperatures and are therefore susceptible to damage. MoSi2 heating elements are available in various grades. The highest grade can operate at 1850°C, enabling their use in a wide range of high-temperature gas conversion processes. The electrical resistivity of the elements is a function of temperature. However, the resistance of these elements does not change with aging. Only a slight decrease in resistance occurs during initial use. As a result, a failed element can be replaced without affecting other connected elements when installed in series. The advantage of MoSi2 elements is that they can provide up to 350 kW / m -2 High surface loads up to

[0029] According to a preferred embodiment, FeCrAl (Fecralloy) is the preferred electric heating element. FeCrAl resistance wire is a robust heating technology due to its resistivity and ease of coating. The load can be controlled by a relatively "simple" on / off control. High voltages can be applied to deliver the heating load. However, this is not commonly applied as it places extra strain on the electrical switch and requires suitable refractory materials to provide sufficient electrical insulation. In addition, Fecralloy heating elements have favorable life and performance characteristics. They are capable of operating at relatively high temperatures (up to 1300°C) and can withstand good surface loads (approximately 50 kW / m -2 ) Fecralloy heating elements can be used in oxidizing atmospheres (>200 ppm O2) to maintain a protective Al2O3 layer on the element.

[0030] The maximum temperature achievable in the reactor configurations of the present disclosure is primarily limited by the type of heating element used. According to certain embodiments of the reactor systems disclosed herein, the reactor configurations are designed to have reactor temperatures of at least 200°C, preferably 400-1400°C or 500-1200°C, and even more preferably 600-1100°C, depending on the type of reaction and reactor system. For example, the preferred reaction temperature range for homogeneous cracking of ethane may be 650-1050°C, while for homogeneous methane cracking it may be 1750-2100°C. Similarly, for steam-methane reforming, the preferred temperature range for catalytic processes may be 400-850°C, depending on the type of catalyst used. Generally, the use of a catalyst can push the preferred range toward lower temperature values, with the amount of reduction varying depending on the type of catalyst and reaction system. For example, the preferred range of reaction temperature for ammonia cracking is 850-950°C for Ni catalysts, but 550-700°C for Cs-Ru catalysts.

[0031] The heating elements used in the systems of the present disclosure may have different types of appearances and forms, such as round wire, flat wire, twisted wire, strip, rod, rod over band, etc. Those skilled in the art will readily understand that the form and appearance of the heating element is not particularly limited, and will be familiar with selecting appropriate dimensions.

[0032] According to some embodiments, the PW configuration depicted in FIG. 1(a) may comprise multiple conductive wires 104 spanning the distance between the two sidewall portions 100, and the wires 104 may be configured so that they are substantially parallel. The wires 104 may be configured as a single electrical circuit spanning all of the wires in a single modular unit, or alternatively, each individual wire may be configured to operate as a standalone circuit. In some embodiments, the wires 104 may have lengths of 0.1-10 m, 1-9 m, 2-8 m, or 3-7 m. Additionally, the wires 104 may be configured to have diameters of 10-500 μm or 100-400 μm, providing three to four orders of magnitude of flexibility in power generation or voltage / current specifications. For example, according to one embodiment, the wires 104 may have lengths of 10-500 μm or 100-400 μm. -6 Applying a current of 1200 A to a wire with a resistivity of Ω·m and dimensions of 0.5 m long and 500 μm diameter generates 3.67 MW. An alternative embodiment with a length of 10 m and a diameter of 50 μm generates 7.34 GW, which is 2000 times greater than the power of the previous embodiment. It should be noted that the desired length of each wire 104 can also be obtained by connecting shorter wires in series, allowing flexibility to meet mechanical and thermal stability requirements. For example, a 1-m long wire can be obtained by connecting ten 0.1-m long wires in series or twenty 0.05-m long wires in series. Similarly, flexibility in the electrical properties of the wire (i.e., the resistivity can be increased by 10 -9 ~10 -5 The choice of metal, which can vary in Ω·m, can provide an additional two orders of magnitude of variation in the wire.

[0033] According to some PW configurations of the present invention, the overall system may include multiple modular units, each comprising multiple layers of parallel wires, each experiencing the same potential difference while feed gas flows between the wires. FIG. 2(a) depicts one representative configuration of a single-layer modular unit. As shown in FIG. 2(a), a single unit may comprise a wall portion 202 and a layer of parallel wires 204, and the multiple layers of wires may also be staggered to reduce the effective hydraulic radius. As shown in FIG. 2(b), individual modular units (such as those disclosed in FIG. 2(a)) 206 may be positioned along the flow direction of a reaction zone (or heating zone) 208 to optimize the footprint. Such a reaction zone (or heating zone) 208 is referred to herein as a PW module. According to some embodiments, in a PW module, each unit may be independently subjected to a fixed voltage difference to enable regulated heat injection rates and meet electrical constraints (i.e., limits on maximum voltage and / or current).

[0034] The PW configuration is particularly advantageous over prior art systems because it provides (i) uniform heating, and (ii) additional flexibility in the design space, particularly the choice of space-time, inlet conditions (temperature, composition), wire spacing (or solids-to-flow volume ratio), number of wires per module, etc., which can be used to meet production goals and electrical / mechanical constraints for a given system. Furthermore, the PW configuration can be arranged in multiple spatial orientations, allowing optimal use of the footprint for a given production goal.

[0035] As noted above, unlike prior art systems, the PW configuration disclosed herein provides uniform heating to the reactants passing through the modular units. Prior art for endothermic chemical reaction processes typically involves internal flow of reactants through tube or packed-bed reactor configurations (for homogeneous and catalytic reactions, respectively), with heat supplied to the outer tube walls via radiative heat transfer by burning fossil fuels in a furnace. Therefore, heating efficiency in these configurations is lower due to the addition of thermal resistance (external to the furnace and internal solid surfaces) before heat is provided to the fluid phase. In contrast to these prior art systems, in the configurations disclosed herein, heat is supplied to the reactants electrically (preferably using a renewable electrical source) by generating heat uniformly within solid reactor component materials that directly supply heat to the fluid phase, thereby minimizing additional thermal resistance and thus potentially resulting in higher overall thermal efficiency of the reactor.

[0036] In certain prior art systems, the reactor dimensions (such as the hydraulic radius of the flow channel) are larger. For example, in a conventional tube reactor, the tube diameter is on the order of 1 inch, which results in a larger temperature gradient (or difference between the solid and fluid phases) and lower heating efficiency. According to the systems disclosed herein, the hydraulic diameters within the flow channels (e.g., wire spacing in PW configurations, plate spacing in PP configurations, and hole diameters in SM / wire mesh / gauze reactor configurations) are small, resulting in much shorter diffusion and conduction times compared to the spatial times in prior art designs. Therefore, the configurations are optimized to achieve a lateral mass Peclet number (p m ) and the transverse thermal Peclet number p h but,

[0037]

number

[0038]

number

[0039]

number

[0040]

number

[0041] In some embodiments, a lateral temperature gradient may exist such that the gas near the wire is hotter than the gas at the centerline. In such systems, higher conversion rates may be obtained near the solid surface and lower conversion rates may be seen at the centerline. Some embodiments implement staggered stacking of wire layers to further enable more efficient and uniform heat delivery, thereby bringing cooler feed (from one layer) closer to the wire surface of the next layer (effectively reducing the apparent hydraulic radius), resulting in more efficient cracking. Additionally, the flexibility of stacking layers or multiple units in the flow direction may also provide the ability to reduce the overall height of each module without losing productivity while staying within electrical constraints. Thus, the modular systems disclosed herein can be designed to fit the space requirements for specific deployments in a wide variety of reactor systems.

[0042] The simplest reduced-order mathematical model describing the material and energy balances for both catalytic and homogeneous reactions for specific embodiments of PW and other configurations (e.g., PP, monolith, wire mesh, gauze) can be expressed in terms of multiple concentration and temperature modes corresponding to their averages in the fluid and solid phases, and interfacial heat / mass fluxes. Lateral gradients can be captured using the transfer coefficient concept, which yields accurate results for homogeneous and / or catalytic reactions. The only differences include (i) interfacial heat fluxes that include a radiation term via the effective transfer coefficient or directly via the Stefan-Boltzmann equation, (ii) a source term representing electrical resistance heating in the solid phase, and (iii) a sink term representing the heat absorption required for the gas conversion process.

[0043] For certain embodiments of the PW configuration, the solid phase heat source term in modeling the system disclosed herein can be expressed as:

[0044]

number

[0045] In this heat source term,

[0046]

number

[0047] In some embodiments, a modular reactor segment comprises a set of parallel plates 106, as shown in FIG. 1(b). In such embodiments, a voltage difference is applied across the length of the plates 106 while the feed gas flows along their width. This configuration has similar advantages to the PW configuration with respect to the width of the plates 106. Similarly, the number of stacked layers in a PW configuration is similar to the ratio of plate width to thickness in a PP configuration. As with the embodiment of a single PW module shown in FIG. 2(b), an embodiment of a PP module may comprise multiple PP units in series, providing similar advantages. According to some embodiments, having a longer length in the flow direction in a PP configuration may require higher power for the same productivity, which may exceed the current-voltage limitations for the unit. Therefore, stacking such units in series (as with a PW configuration as shown in FIG. 2(b)) provides flexibility within electrical constraints.

[0048] The low-order mathematical model for the PP configuration can be either a multi-mode non-isothermal short monolith reactor model or a long monolith model, depending on the axial Peclet number. The heat source term in this configuration is also given by equation (3) above with reference to the PW configuration of this disclosure.

[0049] In another configuration, a short monolith (or hole-thin plate with short channels) 108 is used as one unit (shown in FIG. 1(c)), while one module can consist of several such SM units stacked in the flow direction. In such an embodiment, the feed gas flows internally through the short channels and a potential difference is applied perpendicular to the flow along one of the sides of the plate. The mathematical model is a multi-mode non-isothermal short monolith reactor model, where the heat source can be expressed as:

[0050]

number

[0051] In the wire mesh configuration, a unit may consist of a single wire mesh 110 as shown in FIG. 1(d) or multiple wire meshes 110 stacked in the flow direction, while a module may consist of multiple such units stacked in the flow direction. Each unit may be subjected to the same potential difference along one of its sides, as in the SM configuration. Thus, the feed gas flows through one wire mesh and then another, where partial conversion occurs at each mesh, resulting in the desired conversion at the exit of the last mesh. The mathematical model of the flow and reaction through each wire mesh or gauze is the same as that for the short monolith. The heat source term may also be the same as that for the specific SM configuration disclosed herein (Equation 4), where the channel length of the SM unit is equal to the number of wire meshes times the wire thickness of the wire mesh unit.

[0052] result While the configurations disclosed herein can be utilized with any endothermic process, performance metrics can be modeled using the exemplary endothermic process of ethane cracking for ethylene production. In addition, the inventors chose the PW configuration as a proxy for demonstration because it can be stacked in the flow direction, providing additional flexibility that can facilitate evaluation of electrical constraints. The examples disclosed herein are examples calculated using the models disclosed herein.

[0053] Thermodynamic and kinetic aspects of ethane cracking and other endothermic reactions. To accurately estimate the process conditions and equilibrium constraints for the systems disclosed herein, initial design considerations were directed to thermodynamic calculations based on reaction thermochemistry. Based on standard thermodynamic data, Figures 3(a), (c), and (e) depict the calculated maximum (equilibrium) conversion possible for the specific reactor configurations disclosed herein as a function of operating temperature for ethane cracking, SMR, and DMR, respectively. As shown in these figures, as the operating temperature increases, the conversion rate increases (which is typical for reversible endothermic reactions). This is expected because the equilibrium constant for endothermic reactions increases exponentially with operating temperature. Therefore, if the desired conversion rate is high, a higher operating temperature is required in the reactor, which may result in additional material / safety-related constraints. Therefore, such calculations play an important role in material screening to ensure safe operation.

[0054] Figures 3(a), (c), and (e) also illustrate the differences between adiabatic, isothermal, and electrification operation for ethane cracking, SMR, and DMR, respectively. For example, in isothermal operation (heat is supplied to maintain a constant temperature within the reactor), the conversion rate can reach an equilibrium value as indicated by the isothermal reaction path. In contrast, in adiabatic operation (no heat is supplied), as the reaction proceeds, the reacting fluid cools as the reaction consumes the fluid's sensible heat, resulting in a decrease in temperature and a corresponding decrease in conversion rate (see adiabatic reaction path). Conversely, in electrification operation (Joule heating is supplied through a power source), depending on the space-time and the power being supplied, the conversion may begin along the adiabatic path and then follow a path toward equilibrium, ultimately resulting in a higher conversion rate (near 100%). This is because heat is continuously supplied, and the operating temperature can increase above the target isothermal temperature, resulting in a much higher conversion rate. In these figures, the dashed curves (3a, 3b, and 3c) correspond to ratios of 0.02:1, 0.2:1, and 2:1, respectively, of the supplied electrical heat compared to the endothermic heat requirement to maintain isothermal operation (at the target operating temperature). For example, in some embodiments designed for ethane cracking with an inlet fluid temperature of 1100 K (approximately 827°C), the equilibrium conversion may be nearly 80%, which may be achieved in isothermal operation by maintaining constant reactor temperature through the heat supply. However, adiabatic operation at the same inlet feed temperature results in a lower conversion of 18%, with the final temperature dropping to 883 K (approximately 610°C). Electrified operation with an 1100 K feed may initially follow an adiabatic path, resulting in lower temperatures (depending on the power supplied and space-time), but may also result in higher fluid temperatures than the feed, thereby resulting in a conversion greater than 80%. Similar trends are observed for other endothermic processes such as SMR and DMR, shown in Figures 3(c) and (e).

[0055] Although the equilibrium conversion versus temperature relationship is derived solely from thermodynamic considerations, the results shown in Figures 3(a), (c), and (e) apply only to closed systems (corresponding to space time approaching infinity or zero flow). In open systems, the actual conversion obtained at any given space time depends on reaction kinetics, operating conditions (temperature and operating mode), and flow distribution and will be lower than the equilibrium conversion. Steady-state conversion can be calculated using available kinetic models for these endothermic processes. For demonstration purposes, the reaction kinetics of ethane cracking, SMR, and DMR are selected here from conventional methods for performing thermodynamic and conversion calculations. Figures 3(b), (d), and (f) show equilibrium conversion versus space time for ethane cracking (using a feed at 1100 K (approximately 827°C)), SMR (using a feed at 1000 K (approximately 727°C)), and DMR (using a feed at 1100 K (approximately 827°C)), respectively. These figures show that near-equilibrium conversion can be achieved in shorter space times in isothermal operation and in relatively long space times in adiabatic operation. For example, as shown in Figure 3(b), for ethane cracking using a feed at 1100 K (approximately 827°C), near-equilibrium conversion (i.e., approximately 80%) can be achieved in a space time of 2 s in isothermal operation and in a space time of 100 s in adiabatic operation. Similarly, for SMRs, with a feed at 1000 K (approximately 727°C), conversion rates close to equilibrium (i.e., approximately 80%) can be achieved in a space time of 2 ms in isothermal operation and 10 ms in adiabatic operation, as shown in Figure 3(d). For DMRs, with a feed at 1100 K (approximately 827°C), conversion rates close to equilibrium (i.e., approximately 90%) can be achieved in a space time of 1 s in isothermal operation and 10 s in adiabatic operation, as shown in Figure 3(f). In addition, these figures also depict the conversion from electrification operation achieved at various space times.Two important points to note from these figures are: (i) depending on the space-time and the electrical heating provided, conversion in electrified operation can result in higher values ​​(closer to 100%) than in isothermal operation (of course, higher fluid temperatures will result as well), and (ii) the higher the power supply, the shorter the space-time required for the same target conversion. Thus, at a given temperature limit (related to material constraints), a target production rate can potentially be achieved in electrified operation, as long as electrical and other process constraints are taken into account. It should be noted that depending on the temperature of the feed entering the heating section, there may be a small conversion rate, which may slightly change the starting point in Figure 3, but does not change the final conclusion.

[0056] Space-time requirements and process temperature are important design parameters that must be considered to achieve a desired level of conversion. While Figures 3(a), (c), and (e) provide partial information (the relationship between conversion and temperature), they do not estimate specific space-time requirements. However, they provide tentative target fluid temperatures for desired conversions. Similarly, Figures 3(b), (d), and (f) provide tentative space times for specific target fluid temperatures (1100 K or 1000 K). For example, Figure 3(b) shows that for an embodiment with a target fluid temperature of 1100 K (approximately 827°C) in ethane cracking, 80% conversion requires a space time of approximately 2 s. Similarly, for a desired conversion of 50% at a target fluid temperature of 1100 K (approximately 827°C), the suggested space time is approximately 0.3 s. In other words, a higher desired conversion requires a longer space time, as one might intuitively expect, so that the reactants have sufficient contact time for conversion.

[0057] The selected target values ​​of space time and operating temperature are also determined based on the two criteria mentioned above (p h< 1, and Da ≫ 1) must be satisfied. This requires evaluation of diffusion and reaction times. Characteristic reaction times can be obtained from the reaction rate equations at various temperatures and conversion levels. Figure 4 shows the reaction time and conversion rate at various temperatures for ethane cracking. This plot shows that reaction times can vary by as much as six orders of magnitude depending on the fluid temperature. Similarly, Figure 5 shows the conversion rate versus space time for ethane cracking in a parallel wire configuration (same scheme as Figure 3, but at various other temperatures). These plots (shown in Figure 5) also suggest that at a given target temperature, there is a maximum limit to the conversion rate that can be achieved regardless of how large the space time is. This maximum limit corresponds to the equilibrium value shown in Figure 3(a). These plots (Figures 3, 4, and 5) can be used to select design and process parameters such that the Dankeler number is greater than 1 to achieve higher conversion rates and refine the target temperature and corresponding space time. Similar calculations can be performed for any other endothermic reaction; Figures 3-5 may vary quantitatively, but the nature and qualitative characteristics remain the same.

[0058] In contrast to prior art systems where the difference between solid and fluid temperatures can be as high as 100-400°C, some embodiments of the disclosed system can be designed to limit such a difference to within 50-100°C. Therefore, based on material sensitivity, a maximum solid temperature can be selected to ensure safe operation, which leads to a rough estimation of fluid temperatures. Once a target fluid temperature is selected, a reactor model with an intermediate level of mixing (depending on the reactor configuration and the design of each module) can be utilized to obtain one of the key design parameters—space time. An appropriate value of space time can be used to determine the reactor volume based on the desired production capacity of the reactor for the desired conversion rate.

[0059] Power requirements and voltage / current constraints Power requirements needed to carry out endothermic reactions

[0060]

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[0061] Power requirements based on endothermic chemistry and flow conditions In the example of ethylene production from ethane cracking, the power requirements

[0062]

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[0063]

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[0064] As an example, a world-scale ethane cracking plant may have an ethylene production capacity of 1 megaton per year (MTA), which corresponds to an ethylene production rate of 1.13 kmol / s or F in = 1.25 kmol / s equivalent to an ethane feed rate (χ e (Assume a conversion of 90%). This is at a pressure of 1 atm and T fin = 100m of ethane at 950K (approximately 677°C) 3 / s. The target reaction temperature T f = 1300K (approximately 1027℃), the spatial time t c) can be selected using Figure 3(a) or Figure 5, which means that t c = 10ms. Therefore, the power requirement

[0065]

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[0066]

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[0067] Similarly, in another example of a lower capacity ethane cracker producing 250 kilotons per year (kTA), the power requirements, ethane inlet flow rate, and fluid volume will be proportionally lower (for the same space time and inlet / outlet fluid temperatures). Specifically, a 25 m / s (314 mol / s) at 1 atm and 950 K (approximately 677°C) 3 A 250 kTA ethane to ethylene plant (producing 283 mol / s of ethylene at 1300 K (about 1027 °C)) with a feed / inlet flow rate of 1000 kJ / s would require 54 MW of power. c = 10 ms), the total fluid volume in this case is approximately 0.25 m 3 These numbers in the formula are merely exemplary and may vary depending on the particular reaction system and feed conditions.

[0068] Power generation and heating module design If the total power required is supplied through electrical heating, it is important to operate within electrical constraints such as maximum current or voltage limits. According to some embodiments, a wire (with electrical resistivity ρ) subjected to a potential difference of ΔV ise , length L, and diameter d w The power (P0) generated in the

[0069]

number

[0070] For example, applying a 75 volt potential difference across a 1 meter long wire (100 μm diameter, 1.4 Ω.μm resistivity) results in a current of approximately 0.42 Amp, generating approximately 31.56 W of power. Thus, if a maximum current of 1200 Amp is allowed (as one of the electrical constraints), a basic unit consisting of approximately 2852 wires as depicted in FIG. 2(a) can generate approximately 90 kW or more of power. Therefore, to achieve a plant capacity of 250 kTA (requiring approximately 54 MW of power), approximately 600 such basic units are required, which can be achieved with many combinations, such as one module containing approximately 600 basic units, or two modules containing approximately 300 basic units, or three modules containing approximately 200 basic units. FIG. 6 shows a schematic diagram of a module 602 consisting of 125 basic units 604, which can correspond to a module generation capacity of approximately 50 kTA. Five such modules may be required to have an ethylene plant with a production capacity of 250 kTA. The number of modules is flexible and can be selected depending on the desired production capacity and footprint constraints. According to some embodiments, the production plant includes 1 to 50 modules, each module including 10 to 1,000 basic units. These basic units can be designed and arranged in a modular configuration to optimize the footprint and meet voltage / current constraints. For example, there is flexibility in the design of a single basic unit with respect to the number of parallel wires stacked vertically in a single layer (as shown in FIG. 2(a)) and the number of layers stacked in the flow direction. According to some embodiments, a basic PW unit (shown in FIG. 2(a)) comprises 200 to 10,000 individual parallel wires spanning the distance between the two wall sections of the unit. More preferably, some embodiments of a basic PW unit may include 100 to 10,000 individual wires, and even more preferably 2,000 to 3,000 individual wires. The number of wires stacked vertically in a single layer determines the height of the unit or module, and the number of layers determines the flow length of the unit.According to some embodiments, an average layer comprises 10 to 5,000 vertically stacked wires, or preferably 100 to 500 vertically stacked wires. According to some embodiments, a single basic PW unit comprises 2 to 50 layers, or preferably 5 to 10 layers. Additional flexibility exists regarding the number of units stacked in the flow direction, which determines the length and capacity of the module. The number of units can be selected based on constraints regarding maximum inlet velocity and space-time requirements. According to an exemplary embodiment utilizing a PW configuration, FIG. 6 shows a schematic diagram of a module 602 incorporating multiple PW units 604 for transient simulations, with detailed wire placement to demonstrate their effectiveness. FIG. 6 depicts multiple views of an exemplary embodiment of a PW unit 604, including a diagram of how the modular units are positioned within the module 602 and a cross-sectional view showing the wire configuration. In some embodiments of a system incorporating multiple such modular units 604, the system may comprise 10 to 2,000 individual basic PW units (as described above).

[0071] According to some embodiments, the configuration may include any type of modular unit disclosed herein, including, but not limited to, PW, PP, SM, and wire mesh configurations. A schematic diagram of a basic individual unit in a PW configuration is depicted in FIG. 2(a), and those in the PP, SM, and wire mesh configurations are depicted in FIGS. 1(b), 1(c), and 1(d), respectively. According to some embodiments, in the PW configuration as well as in other configurations, the production plant may include 1 to 50 modules, each of which may include 10 to 1,000 basic units. According to some embodiments, in the PP configuration, a basic unit (shown in FIG. 1(b)) may include 10 to 5,000 vertically stacked plates, or preferably 100 to 500 vertically stacked plates. Thus, one of the key advantages of the systems disclosed herein is achieved by using modular units to provide a wide range of customization and flexibility without requiring a complete system redesign.

[0072] Transient behavior of modular units In some embodiments of the systems disclosed herein, transient simulations can be performed to ensure realistic performance of the module based on flexible designs including reactor size, process conditions, and electrical parameters / constraints.

[0073] Process Parameters: To design the parameters for some embodiments disclosed herein, Figure 3(a) can be utilized to select a target fluid temperature for the desired conversion (preferably greater than 80%), and then an appropriate space time can be selected from Figures 4 and 5. According to one embodiment, for an exemplary demonstration of a transient simulation, a target temperature of 1300 K (approximately 1027°C) and a space time of 0.01 s (10 ms) can be selected. For this demonstration, the inlet temperature of ethane was assumed to be 950 K (approximately 677°C).

[0074] Geometric Parameters: According to an exemplary embodiment, a PW module 602 as shown in FIG. 6 consists of 125 PW basic units 604. In such an embodiment, each PW basic unit consists of eight layers of 326 parallel wires, for a total of 2608 wires per unit. Each wire has a length of 1 m, a diameter of 100 μm, and a resistivity of 1.4 Ω μm. In all layers, the parallel wires are spaced 1.51 mm apart (i.e., the ratio of lateral spacing to diameter is approximately 15). Each layer is spaced 0.5 mm apart (i.e., the ratio of axial spacing to diameter is 5). The resulting height of each unit (same as the height of each module) is 0.5 m, and the flow length of each unit is 4.3 mm. Assuming the spacing between each unit is the same as the unit's length (i.e., the ratio of spacing to length is 1), the total length of each module is approximately 1.1 m. Therefore, the dimensions of the reactor portion of each module are 1 m x 0.5 m x 1.1 m (i.e., 0.55 m 3 In such an embodiment, in each module, there are 125 x 8 (=1000) wires in the flow direction, so the effective solid length in the flow direction is 0.1 m, and a speed of 10 m / s is required to achieve a space time of 0.01 s. Therefore, the space time based on the total length of the module (which is about 10 times larger than the effective solid length due to the spacing between the wires and the spacing between each unit) is approximately one-tenth, or 0.1 s.

[0075] Electrical Parameters: In the exemplary embodiment described above, each unit receives 79 volts, resulting in a total current of 1157 Amp per unit (or 0.44 Amp per wire), generating a power of 35.1 W per wire or 91.5 kW per unit. As a result, the module can generate 11.44 MW of power and produce approximately 52 kTA of ethylene.

[0076] The reactor configuration can be modeled as a series and parallel combination of two-phase short monolith models, which leads to transient profiles of temperature and conversion at the outlet of the module as shown in Figure 7(a) for an inlet velocity of 10 m / s. Similarly, the spatial profiles at t = 10 s are shown in Figure 7(b).

[0077] As disclosed herein according to at least this exemplary embodiment, the difference between the fluid temperature and the solid temperature is approximately 60°C (steady-state solid and fluid temperatures at the outlet are 1380K (approximately 1107°C) and 1320K (approximately 1047°C), respectively). Additionally, according to some embodiments, the time to achieve steady state is less than 1 s, or more preferably less than 0.8 s, as shown by FIG. 7(a). Such a short period to steady-state operation corresponds to a fast start-up time compared to hours to days in conventional prior art. Additionally, the spatial profile in FIG. 7(b) shows that each wire provides gradual conversion. The first few units near the inlet primarily contribute sensible heat, which increases the temperature of the feed stream. In fact, the spatial time for each wire is 10 μs, and therefore conversion begins at a higher temperature (approximately 1200K (approximately 927°C)). Therefore, once the gas temperature reaches approximately 1200K (approximately 927°C), each wire provides partial conversion. According to some embodiments, at the outlet of the module, a conversion of at least 75% is achieved, more preferably at least 80% or 85%.

[0078] According to some embodiments, the modules disclosed herein achieve a uniform velocity distribution across the cross section of the module and a rapid quench after exiting the wire section. Depending on the specific parameters required for such a module, additional reactor length (and volume) may be required for feed distribution, product collection, and quenching. To prevent or mitigate product loss due to additional reaction time at temperature, it is preferable to quench the feed before collecting it. In the exemplary case where the feed is considered to be flowing at a velocity of 10 m / s with a cross section of 1 m x 0.5 m and a flow length of 1.1 m, the distributor and collector lengths may total 5 m, and the total footprint required for each module would be 1 m x 0.5 m x 6 m (approximately 3 m 3 ) Thus, in some embodiments of the PW configuration, the volume of a module capable of generating 11.44 MW of power or producing approximately 50 kTA of ethylene is 3 m 3 Thus, according to some embodiments, five of such modules are approximately 15-20 m 3 ethylene production capacity of 250 kTA with a reactor footprint of 1000 m 3 This utilizes a significantly smaller footprint when compared to conventional prior art which may be on the order of 1000 sq ft.

[0079] Advantages of the new reactor configuration According to some embodiments, the reactor configurations disclosed herein have many advantages over the prior art, particularly due to the modularity / flexibility of the units and the possibility of coupling with renewable power.

[0080] According to some embodiments, the systems of the present disclosure are based on all-electric heaters (i.e., they do not burn fossil fuels to provide heat as in conventional approaches), and therefore, these systems have the utility of providing reduced, zero, or net-negative CO2 emissions while producing value-added chemicals. Therefore, when renewable power (solar, wind, geothermal, water, nuclear, etc.) is used to generate electricity, CO2 emissions can be reduced or even completely eliminated. For example, prior art ethane cracking technology releases approximately 1.2 moles of CO2 into the atmosphere per mole of ethylene produced. In other words, a world-class ethane cracker (producing 1000 kTA of ethylene) releases approximately 1800 kTA of CO2 into the atmosphere. According to some embodiments, reduced or zero CO2 emissions are achieved with the SMR (steam methane reforming) process, while negative CO2 emissions are achieved with DMR (dry methane reforming) and RWGS (reverse water gas shift) reactions.

[0081] According to some embodiments, the disclosed system may be applied to a wide variety of processes, including homogeneous and catalytic reactions. The disclosed system may also be applicable to a wide variety of endothermic processes, including: (1) cracking of ethane, propane, naphtha, crude oil, etc.; (2) pyrolysis of methane; (3) steam or dry methane reforming (SMR or DMR); (4) reverse water gas shift (RWGS); (5) ammonia decomposition; and (6) other such endothermic reactions. In some embodiments, the disclosed system may be used to promote: (1) non-catalytic homogeneous reactions (i.e., reactions in the fluid phase); and / or (2) surface-catalyzed reactions (i.e., reactions on a solid surface). For endothermic reactions requiring a catalyst, in some embodiments, the interior (i.e., the interface in contact with the fluid) of a plate or monolith of PW, gauge, or wire mesh configuration or PP configuration may be coated with a thin porous layer of washcoat containing a catalytic agent (as is done in monolith catalytic converters used to treat automobile exhaust gases).

[0082] Conventional technologies described herein have low heating / thermal efficiencies of 30-40%. For example, ethane cracking technology uses approximately three times the energy required above the thermodynamic minimum (174.4 kJ / mol). According to some embodiments disclosed herein, direct electrical heating of tube / wire / metal monolith reactors can significantly reduce energy requirements and result in heating efficiencies of greater than 80%, 85%, 90%, 95%, or 99%. In some embodiments, the same efficiency benefits apply to endothermic reactions such as steam methane reforming (SMR), dry methane reforming (DMR), reverse water gas shift (RWGS) reactions, and others that use CO2 as a reactant.

[0083] According to some embodiments, the transient times in the proposed technology are on the order of a few seconds (as shown in FIG. 7(a)), compared to hours to a day for conventional technology from prior art systems, thereby resulting in lower start-up and shutdown times. This translates into reduced generation losses while performing maintenance on the presently disclosed system.

[0084] According to some embodiments, the systems disclosed herein include a modular design that provides flexibility and ease of scale-up. The presently disclosed reactor configuration is modular, offering significant flexibility by allowing system sizing based on process constraints, including local (preferably renewable) energy availability and voltage-current limitations. In particular, some embodiments of the disclosed PW systems offer flexibility with respect to process, material, and geometric parameters to accommodate various constraints related to production, space, capital costs, and current / voltage limitations. For example, according to some embodiments of the present invention specifically designed for ethane cracking using PW modules, the space time can be selected in the range of 0.1 to 1000 ms (preferably 0.1 to 300 ms, more preferably 1 to 100 ms). The inlet temperature can be as low as 800 K (preferably as low as 700 K, more preferably as low as 600 K) to as high as 1100 K (preferably as high as 1200 K, more preferably as high as 1300 K). The length of each wire can vary from 0.25 to 4 m (preferably 0.5 to 2 m) depending on production targets. The wire diameter can be selected between 25 and 750 μm (preferably between 50 and 500 μm). The spacing between the wires can be between 0.1 and 20 mm (preferably between 0.1 and 10 mm). The number of wires in each unit can vary between 10 and 10,000 (preferably between 50 and 5,000, more preferably between 500 and 3,500), and the resistivity range of the wire material can be between 10 and 10,000 (preferably between 50 and 5,000, more preferably between 500 and 3,500). -9 ~10 -5 The electrical resistance can be Ω·m, which ranges from a variety of metals (including, but not limited to, the materials disclosed herein). The solid volume fraction can be selected from 1 to 30% (preferably 1 to 20%).

[0085] Additionally, in some embodiments, each module can be independently stacked in parallel or series, providing flexibility in scale-up design. In some embodiments of the PW configuration, the module may comprise multiple layers (or sets) of parallel wires stacked along the flow direction. Such stacks may also be staggered, which can reduce the effective spacing between the wires and result in better heat transfer between the solid and the fluid. In some embodiments, the proposed system allows for independent placement of each module within the plant to facilitate achieving the targeted large-scale production, as discussed above. Because each module can be positioned in any direction, the targeted large-scale production can be achieved by stacking modules in parallel and / or series in any direction. The number of such modules depends on the targeted production volume (as discussed above). For example, according to an exemplary embodiment, using PW modules 602 as shown in FIG. 6, a 1000 kTA ethylene plant may require 200 such modules, a 100 kTA ethylene plant may require 20 such modules, and a 400 kTA ethylene plant may require 80 modules. If the heating efficiency is low, the number of modules may be increased accordingly to achieve the target production rate. For example, if the heating efficiency is reduced from 100% to 80%, the number of modules required in a 400 kTA ethylene plant may increase from 480 to 100. These modules may be stacked along the flow or perpendicular to the flow, depending on the availability of space. Flexibility in the selection of process parameters and material / geometric properties can also be used to optimize the footprint to meet space constraints.

[0086] Due to the modularity of the disclosed configuration, such a system facilitates ease of safety and maintenance, as well as substitution and adaptation of new safety / mitigation strategies with negligible extra operating costs. For example, in some embodiments, if a safety issue arises or maintenance / safety check is required, the entire module does not need to undergo a shutdown or startup cycle (as is required in conventional prior art approaches). Instead, the modular design allows for the shutdown of small sections (or specific modules) while leaving other sections in operation. Similarly, replacement of failed modules can be done in the same manner, leading to much lower production losses and higher working capital utilization. The adaptation of new mitigation strategies is simplified. For example, coke formation mitigation methods (based on magnetic or electromagnetic pulses or high-frequency vibrations) can be easily incorporated to prevent coke formation due to thermal cracking and similar processes.

[0087] In some embodiments, the all-electric heater design proposed in the disclosed configuration provides uniform temperature distribution, in contrast to prior art combustion furnace designs that utilize radiant fuel burners. Additionally, while combustion furnace designs require higher local temperatures (approximately 80%) to effectively heat the reactor walls to the target temperature, the disclosed electric heater configuration facilitates the increase in the target wall temperature directly through controlled Joule heating. This results in a more uniform temperature distribution, thereby providing more consistent and uniform reaction conditions along with higher heating efficiency and longer system life. This specification includes the disclosure of the following inventions. [1] 1. A modular reactor system for conducting an endothermic reaction, said modular reactor system comprising: a. At least one module, each module comprising: i. a plurality of wall sections positioned to surround a reaction zone inside a channel configured to allow fluid to flow through the reaction zone; ii. a power source; iii. at least one resistive heating element passing through the reaction zone, mechanically connected to the wall section and electrically connected to the power source; iv. the at least one resistive heating element is electrically insulated from the wall section; v. the reactor system is configured to allow flow of a fluid containing one or more reactants; vi. the reaction zone is adapted to convert reactants, when present in the fluid, into products; b. the resistive heating elements of each module are configured to generate resistive heating within the reaction zone such that the temperature of the reaction zone can be adjusted to a desired reaction temperature range; c. The modular reactor system, wherein the at least one resistive heating element comprises a configuration selected from the group consisting of a plurality of wires, a plurality of plates, a wire mesh, gauze, and a metal monolith. [2] a. the at least one resistive heating element comprises a plurality of wires; b. each of said wires is parallel to the other wires; c. each of the wires has a length of 0.1 m to 10 m; d. the wires each have a diameter of 10 μm to 1000 μm; e. The wire is 10 -9 Ω·m~10 -5 The modular reactor system according to [1], having a resistivity of Ω·m. [3] a. the at least one resistive heating element comprises a plurality of metal plates; b. each of said plates is parallel to the other plates; c. the plate has a length (perpendicular to the flow) of 0.1 m to 10 m and a width (along the flow) of 50 μm to 5000 μm; d. The plate has a thickness of 10 μm to 1000 μm; e. The plate is 10 -9 Ω·m~10 -5 The modular reactor system according to [1], having a resistivity of Ω·m. [4] a. the at least one resistive heating element comprises a wire mesh, gauze, or a metal monolith; b. The wire mesh, gauze, or metal monolith has a hydraulic radius of 50 μm to 10,000 μm; c. The modular reactor system of [1], wherein a single wire mesh, gauze, or metal monolith unit has an axial flow length of 50 μm to 5000 μm. [5] a. the module is configured to allow multiple modules to be arranged in parallel and / or series configurations; b. The modular reactor system of [1], wherein the plurality of modules are configured to allow the fluid to flow through the reaction zone of each module. [6] 10. The reactor system of claim 1, wherein the at least one resistive heating element is configured to generate resistive heating within the reaction zone to produce a temperature of at least 200°C. [7] The at least one resistive heating element is selected from the group consisting of FeCrAl, NiCr, SiC, MoSi 2 , NiCu, NiCrFe, MnNiCu, CrAlSiCFe, NiCoMnSiFe, and NiAlTi. [8] a. further comprising a plurality of resistive heating elements; b. the resistive heating elements are positioned such that the species diffusion and heat conduction time from the fluid to the solid is shorter than the space time; c. The reactor system of [1], wherein the resistive heating element is selected to have a transverse thermal Peclet number of less than 1. [9] 1. The modular reactor system of claim 1, wherein the system is configured to facilitate ethane cracking, propane cracking, naphtha cracking, methane pyrolysis, ammonia cracking, methane dry or steam reforming, reverse water gas shift, adsorption-desorption processes, and / or combinations thereof.

[10] 10. The modular reactor system of claim 1, wherein the at least one resistive heating element further comprises a catalyst.

Claims

1. 1. A modular reactor system for conducting an endothermic reaction, said modular reactor system comprising: a. at least one module, each module comprising: i. a plurality of wall sections positioned to surround a reaction zone inside a channel configured to allow fluid to flow through the reaction zone; ii. A power source; iii. at least one resistive heating element passing through the reaction zone, mechanically connected to the wall section and electrically connected to the power source; iv. the at least one resistive heating element is electrically insulated from the wall section; v. the reactor system is configured to allow flow of a fluid containing one or more reactants; vi. the reaction zone is adapted to convert reactants, when present in the fluid, into products; b. the resistive heating elements of each module are configured to generate resistive heating within the reaction zone such that the temperature of the reaction zone can be adjusted to a desired reaction temperature range; c. the at least one resistive heating element comprises a configuration selected from the group consisting of wires, plates, wire mesh, gauze, and a metal monolith; d. the at least one resistive heating element comprises a plurality of wires; e. each of said wires is parallel to the other wires; f. each of the wires has a length of 0.1 m to 10 m; g. the wires each have a diameter of 10 μm to 1000 μm; h. The wire is 10 －９ Ω m to 10 －５ A modular reactor system with a resistivity of Ω·m.

2. a. the at least one resistive heating element comprises a plurality of metal plates; b. each of said metal plates is parallel to the other metal plates; c) the metal plate has a length (perpendicular to the flow) of 0.1 m to 10 m and a width (along the flow) of 50 μm to 5000 μm; d. The metal plate has a thickness of 10 μm to 1000 μm; and e. The metal plate is 10 －９ Ω m to 10 －５ 10. The modular reactor system of claim 1 having a resistivity of Ω·m.

3. a. the at least one resistive heating element comprises a wire mesh, gauze, or a metal monolith; b. the wire mesh, gauze, or metal monolith has a hydraulic radius of 50 μm to 10,000 μm; and c) The modular reactor system of claim 1, wherein a single wire mesh, gauze, or metal monolith unit has an axial flow length of 50 μm to 5000 μm.

4. a. the at least one module is a plurality of modules and is configured to allow the plurality of modules to be arranged in parallel and / or series configurations; 2. The modular reactor system of claim 1, wherein the plurality of modules are configured to allow the fluid to flow through the reaction zone of each module.

5. 10. The reactor system of claim 1, wherein the at least one resistive heating element is configured to generate resistive heating within the reaction zone to produce a temperature of at least 200°C.

6. The at least one resistive heating element may be made of FeCrAl, NiCr, SiC, MoSi ２ 10. The reactor system of claim 1 constructed from a material selected from the group consisting of NiCu, NiCrFe, MnNiCu, CrAlSiCFe, NiCoMnSiFe, and NiAlTi.

7. a. further comprising a plurality of resistive heating elements; b. the plurality of resistive heating elements are arranged such that the species diffusion and heat conduction time from the fluid to the solid is shorter than the spatial time; d) the plurality of resistive heating elements are selected to have a transverse thermal Peclet number of less than one;

8. 10. The modular reactor system of claim 1, wherein the system is configured to facilitate ethane cracking, propane cracking, naphtha cracking, methane pyrolysis, ammonia cracking, dry or steam reforming of methane, reverse water gas shift, adsorption-desorption processes, and / or combinations thereof.

9. 10. The modular reactor system of claim 1, wherein the at least one resistive heating element further comprises a catalyst.

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