Delivery of high temperature hydrogen by hydrocarbon pyrolysis

Abstract

A chemical method and chemical system that pyrolyzes a hydrocarbon feedstock (e.g., methane or natural gas) using a pyrolysis reactor to produce treated hydrogen gas at high gas temperatures. The pyrolysis reactor flows a high temperature fluid stream of pyrolysis products, including hydrogen gas and solid carbon products, to a heat exchanger to cool it into a low temperature fluid stream of pyrolysis products. A treatment system connected to the heat exchanger receives the low temperature fluid stream and generates treated hydrogen gas at low gas temperatures, which is then flowed back to the heat exchanger as a gas stream at low gas temperatures to be used as a working fluid to cool the high temperature fluid stream of pyrolysis gas. Advantageously, this exchange heats the gas stream at low gas temperatures, producing the treated hydrogen gas at high gas temperatures.

Description

[0001] Cross-reference to related applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 63 / 544,929, filed October 19, 2023, which is incorporated herein by reference in its entirety for all purposes.

[0003] Invention Field

[0004] The present invention relates to the production and delivery of hydrogen by thermochemical decomposition or pyrolysis of hydrocarbon feedstocks (e.g., methane), and more specifically to the treatment of hot pyrolysis gases (including hydrogen and carbon) by means of a heat exchanger for cooling prior to carbon removal, and then reusing the cooled hydrogen as a working fluid in the heat exchanger, subsequently delivering it as high-temperature hydrogen at a temperature above 250°C. Background of the Invention

[0006] The United States produces 10 million tons of hydrogen annually. 95% of this is produced through steam methane reforming (SMR), which results in the emission of 100 million tons of CO2. See A. Majumdar et al., “A framework for a hydrogen economy,” Joule, Vol. 4, No. 8, August 18, 2021, pp. 1905-1908.

[0007] Methane pyrolysis, also known as methane cracking or methane decomposition, involves the thermochemical breakdown of a hydrocarbon feedstock, primarily composed of methane (CH4), into its constituent elements: hydrogen (H2) and solid carbon. Note that the decomposition process can form other products such as ethane, ethylene, acetylene, and benzene. The pyrolysis process is typically carried out at high temperatures (usually above 1,000°C) in the absence of oxygen to avoid the formation of gaseous carbon dioxide (CO2) and carbon monoxide (CO). Furthermore, the pyrolysis process is endothermic, requiring a significant thermal input to break the carbon-hydrogen bonds in methane.

[0008] Methane pyrolysis may be the most cost-effective solution for reducing emissions associated with hydrogen production. Unfortunately, existing methods have proven difficult to scale up. The scalability issue has been documented by: M. Steinberg, “The direct use of natural gas for conversion of carbonaceous raw materials to fuels and chemical feedstocks,” International Journal of Hydrogen Energy, Vol. 11, No. 11, 1986, pp. 715-720; and S. Schneider et al., “State of the Art of Hydrogen Production via Pyrolysis of Natural Gas,” ChemBioEng Reviews, Vol. 7, 2020, pp. 1-10. Nevertheless, obtaining hydrogen through methane decomposition promises to be cheaper than producing hydrogen through water electrolysis or steam reforming of existing carbon-captured methane.

[0009] The thermal decomposition of hydrocarbon feedstocks such as methane can occur with or without an active catalyst. Without a catalyst, the thermal decomposition of methane into hydrogen and solid carbon typically occurs at temperatures exceeding 1,000°C. Catalytic materials can reduce the thermal decomposition temperature to 400°C or lower. Catalytic materials used for hydrocarbon decomposition include, but are not limited to, elements from Group VIB and Group VIII of the periodic table, such as iron (Fe), nickel (Ni), cobalt (Co), noble metals, chromium (Cr), molybdenum (Mb), alloys of these metals, and even salts and oxides containing these metals.

[0010] Scalable and cost-effective methane pyrolysis, with or without a catalyst, has not yet been widely commercialized due to numerous challenges in basic process design and scaling up. High-temperature requirements limit the choice of structural materials and necessitate efficient heat transfer at high throughput. The process simultaneously produces gaseous hydrogen and solid carbon, which must be physically separated. In fact, the deposition or coking of solid carbon in the reactor is a major operational problem in the pyrolysis of any hydrocarbon feedstock. Furthermore, the process requires frequent reactor cleaning, leading to downtime and discontinuous operation. Catalysts can become deactivated due to solid carbon deposition and must be replaced or cleaned. Catalyst metals and salts contaminate the solid carbon byproducts, rendering them unusable in all applications. In some cases, the contamination is so severe that the solid carbon byproducts must even be treated as toxic waste.

[0011] Patents concerning the thermal decomposition of hydrocarbon feedstocks have existed for over a century. One of the earliest patents is U.S. Patent No. 1,107,926 to Albert Rudolph Frank, who observed the decomposition of methane at temperatures above 1,200°C. Auguste Jean Paris Jr. first patented the pyrolysis of methane in a molten medium in U.S. Patents Nos. 1,756,877 and 1,392,788 in 1915. Typical hydrocarbon decomposition methods include moving bed and fluidized bed reactors, plasma reactors, microwave reactors, melt bath reactors, and fluid wall reactors. A major challenge in operating continuous or semi-continuous methane pyrolysis processes is overcoming reactor fouling caused by the formation of solid carbon. Solid carbon can coat the reactor surface. This is especially true in cases where pyrolysis occurs on the surface, resulting in the formation of hard carbon deposits. These deposits can accumulate to the point of clogging the reactor, forcing a shutdown and cleaning.

[0012] Plasma, microwave, and fluidized bed reactors typically attempt to overcome carbon fouling by ensuring that energy or heat is transferred to methane away from the reactor walls, thus forming carbon products that can be fluidized out of the reactor. A challenge with these reactors is that their walls often need to be cooled to prevent carbon deposition, which reduces the reactor's energy efficiency.

[0013] Energy efficiency is a critical consideration in the design of methane pyrolysis reactors, especially when the primary objective is to produce clean hydrogen. Clean hydrogen is defined as hydrogen produced with minimal carbon dioxide (CO2) emissions. To minimize CO2 emissions, renewable energy sources such as geothermal, wind, solar thermal, solar photovoltaic, or nuclear power are preferred. However, methane pyrolysis must compete with other methods for producing clean hydrogen, such as water electrolysis, which also uses electricity (ideally from renewable sources). Methane pyrolysis has the potential to use approximately seven times less energy than water electrolysis, but the high temperatures involved in the pyrolysis reaction make developing a high-energy-efficiency process close to the theoretical minimum energy input (~5.2 kWh / kg-H2) challenging. Energy losses can originate from the reactor itself, heating methods, or poor heat recovery from the pyrolysis product gases.

[0014] When considering only the reactor's energy efficiency, it would be beneficial to recover all heat from the pyrolysis product gases and recycle all heat back into the feed gas stream. Since the thermal mass of the feed gas should be roughly equivalent to that of the product gas and solid carbon, it would be ideal if the heat exchanger could transfer all heat from the products to the feed, allowing the pyrolysis reactor to operate near its theoretical minimum energy input. The challenge lies in the fact that hydrocarbon feedstocks undergo thermal decomposition at temperatures above 900°C and even faster above 1,100°C. Adding to the challenge, typical high-temperature pipes and conduits used to transport the feed gas are often made of materials that catalyze hydrocarbon decomposition (e.g., iron and nickel), further reducing the decomposition temperature to near 700°C. This means that if the hydrocarbon feedstock is to be transported through iron- or nickel-based pipes, it is not easily preheated above 700°C, significantly reducing the thermal energy that can be recovered from the product gases. Existing techniques teach the recovery of energy by preheating the methane feed gas with the product gases. The prior art includes U.S. Publication 2021 / 0032102 A2, which specifies a maximum preheating temperature of 700°C.

[0015] Unlike recovering the thermal energy from the high-temperature pyrolysis gases and solid carbon produced by the pyrolysis reaction through preheating of the feed gas, this thermal energy can be used for subsequent processes downstream of the reactor. BASF's U.S. Patent No. 9,834,440 and Molten Industries' U.S. Provisional Application No. 63 / 466,464 describe a process utilizing high-temperature hydrogen to react with carbon dioxide in a reverse water-gas shift reaction to form carbon monoxide and water, a reaction that is thermodynamically favorable at high temperatures. However, this prior art teaches the removal of solid carbon while keeping the hydrogen at a high temperature. This requires a high-temperature cyclone separator or ceramic filter and limits the ability to perform other purification or compression processes on the hydrogen. High-temperature solid carbon removal technologies also have limited particulate matter removal efficiency, particularly for particles with a diameter <10 μm.

[0016] In their article, "Can methane pyrolysis-based hydrogen production lead to the decarbonisation of iron and steel industry?", *Energy Conversion and Management: X*, March 10, 2021, pp. 1-15, Bhaskar et al. also discuss the importance of purifying hydrogen products while maintaining high temperatures. Bhaskar et al. describe using a pressure swing adsorption (PSA) unit to separate hydrocarbons from pyrolysis gases to produce purified hydrogen products. However, this concept faces challenges in commercial implementation because it assumes that the PSA unit operates at 900°C. PSA requires valves, high-pressure pumps, and high-pressure storage tanks to adsorb and desorb gases at pressures up to 40 bar—all of which are difficult to operate at high temperatures. Most steels and stainless steels should not be operated above 760°C. Most pumps have polymer gaskets that cannot function above 300°C. Metal gaskets can be used for higher-temperature operation, but this increases cost and complexity. Examples exist of high-temperature PSA units used for hydrogen purification, reaching temperatures as high as 450°C to achieve a 95% hydrogen recovery rate. If the PSA operates at 450°C, the hydrogen needs to be heated before reaching downstream applications (e.g., iron ore reduction furnaces). Furthermore, for both economic and environmental reasons (since hydrogen is an indirect greenhouse gas), the loss of the 5% of hydrogen produced in the PSA is undesirable. There may also be instances where unreacted methane from the pyrolysis reactor decomposes into solid carbon and hydrogen in the high-temperature PSA. This can pose significant challenges, such as adsorbent material coking, PSA clogging, and adsorbent deactivation within the PSA, leading to reduced separation efficiency and hydrogen recovery rates unless the adsorbent is cleaned or replaced—a costly and inefficient operation requiring plant shutdown.

[0017] To further advance the use of high-temperature hydrogen, the reduction of iron oxides to metallic iron is typically carried out in furnaces (such as shaft furnaces, rotary kilns, or fluidized beds) at temperatures ranging from 650°C to 1,200°C. Industrially, shaft furnaces are most commonly used for reducing iron ore with a mixture of carbon monoxide (CO) and hydrogen (H2). The kinetics of reduction with hydrogen should be faster, thus facilitating the use of fluidized beds. Fluidized bed reduction furnaces can use iron ore powder, which saves energy intensity compared to the iron ore pellet manufacturing required for shaft furnaces. Shaft furnaces are designed to mimic plug flow reactors, where the reaction occurs uniformly radially and the composition changes axially as the gas rises through a packed bed of DRI pellets. Because fluidized beds require the gas to partially lift the weight of the iron ore, the reducing gas in a shaft furnace needs to be delivered at a positive pressure of 1–10 bar above atmospheric pressure.

[0018] Almost every industrial application of hydrogen requires pressurized hydrogen delivery. When hydrogen is burned to generate heat in cement kilns, boilers, or turbines, it typically needs to be delivered at pressures 1-10 bar above atmospheric pressure. When hydrogen is used in chemical production as a feedstock for methanol, olefins, ammonia, or plastics, or as a reducing agent in petrochemical refining, it must be delivered between approximately 30-300 bar. When hydrogen is used as an energy carrier, fuel, or for energy storage, pressures can reach 900 bar. Compressing hydrogen at these high temperatures is extremely difficult in any industrial compressor.

[0019] Therefore, the present invention aims to overcome the limitations of the prior art and to deliver hydrogen at high temperatures in a form suitable for industrial applications with additional requirements (such as high purity or high pressure).

[0020] Purpose of the invention

[0021] The present invention aims to overcome the challenges of transporting high-temperature, high-pressure, and high-purity hydrogen obtained by pyrolysis of hydrocarbon feedstocks (e.g., methane), while also overcoming the challenges associated with handling high-temperature hydrogen.

[0022] Another objective of this invention is to utilize a heat exchange process combined with the pyrolysis of hydrocarbon feedstocks to transport high-temperature treated hydrogen, while simplifying the separation of solid carbon products from pyrolysis gases. Summary of the Invention

[0023] The object and advantages of this invention are provided by a chemical method and chemical system for producing treated hydrogen at high gas temperatures. The chemical system has a pyrolysis reactor for pyrolyzing hydrocarbon feedstocks (e.g., methane or natural gas) (this process is also known as cracking or direct decomposition) to produce a high-temperature pyrolysis product fluid stream containing primarily hydrogen and solid carbon products, which, depending on the operating conditions of the pyrolysis reactor, can be virtually entirely solid carbon.

[0024] The chemical system has a heat exchanger connected to a pyrolysis reactor, which receives a high-temperature fluid stream of pyrolysis products leaving the reactor and delivers a low-temperature fluid stream of these products. In other words, the heat exchanger is configured to cool the high-temperature fluid stream. The chemical system is also equipped with a processing system connected to the heat exchanger. The processing system receives the low-temperature fluid stream of pyrolysis products and processes the pyrolysis products to obtain treated hydrogen gas at a low gas temperature.

[0025] The processing system then returns the gas stream of treated hydrogen at a low gas temperature to the heat exchanger, which serves as the working fluid for cooling the high-temperature fluid stream of the pyrolysis gases. In other words, the heat exchanger exchanges heat between the high-temperature fluid stream of the pyrolysis products and the gas stream of treated hydrogen delivered from the processing system at a low gas temperature. Advantageously, this heat exchange also heats the incoming gas stream at a low gas temperature, so that the treated hydrogen reaches a high gas temperature during this heat exchange while also acting as the working fluid.

[0026] To obtain the desired solid carbon product (e.g., solid carbon), the chemical system operates the pyrolysis reactor at a sufficiently high temperature. For example, the pyrolysis reactor pyrolyzes hydrocarbon feedstocks at temperatures between 500°C and 2,000°C. Operating at high temperatures and producing a sufficiently rapid flow of pyrolysis products is further advantageous because it fluidizes a portion of the solid carbon product out of the pyrolysis reactor. However, such operation results in a high-temperature flow of pyrolysis products that is difficult to handle at its high temperature upon exiting the pyrolysis reactor. However, according to the invention, the disadvantages of high-temperature operation are transformed into advantages by using a heat exchanger that simultaneously cools the pyrolysis products to make them easier to handle, and hydrogen at a high gas temperature is obtained by using a gas stream of hydrogen treated at a low gas temperature as the working fluid. In other words, the chemical system of the invention treats hydrogen at a low temperature and then reheats it, while simultaneously using the same treated hydrogen to cool the pyrolysis products.

[0027] The chemical system can use various types of hydrocarbon feedstocks, including gaseous, liquid, or solid forms containing one or more hydrocarbons, such as methane, butane, propane, ethane, ethylene, acetylene, propylene, natural gas, liquefied petroleum gas, naphtha, shale oil, wood, biomass, organic waste streams, biogas, gasoline, kerosene, diesel fuel, residual oil, crude oil, carbon black, coal tar, crude coal tar, benzene, methylnaphthalene, polycyclic aromatic hydrocarbons, and other such hydrocarbons. Mixtures of any of the above feedstocks with other hydrocarbon feedstocks, as well as mixtures containing any of these feedstocks with other feedstocks such as methane and nitrogen, methane and carbon dioxide, or methane and carbon monoxide, can be used. Preferred embodiments use natural gas or hydrocarbon feedstocks primarily composed of methane. When using methane, the pyrolysis reactor is preferably configured to maintain a hydrogen reaction yield greater than 70%.

[0028] In some embodiments, the processing system includes a separator for separating solid carbon products. Preferably, more than 60% of the solid carbon products are removed or separated from the cryogenic fluid stream of pyrolysis gases by the separator to produce treated hydrogen containing more than 70% hydrogen. Various types of separators can be used in the processing system. In some cases, the separator is a solid filter, such as a cyclone separator, a bag filter, or a HEPA filter. In other cases, the separator is a gas filter, such as a pressure swing or temperature swing adsorption system, a distillation system, or a membrane separator.

[0029] The processing system can be equipped with numerous devices that utilize cryogenic fluid streams, which are easier to process than high-temperature fluid streams, to perform additional useful functions. For example, the processing system may have a compressor for increasing the pressure of the cryogenic fluid stream to between 1 and 1,000 bar absolute pressure. The processing system may also have a measuring device for measuring the flow rate of the hydrogen gas stream processed at low gas temperatures. Furthermore, the processing system may have a gas analyzer for measuring the chemical composition and purity of the processed hydrogen at low gas temperatures.

[0030] The heat exchanger is preferably configured to reduce the temperature of the high-temperature fluid flow of pyrolysis products to below 500°C, and even more preferably below 300°C. Furthermore, the heat exchanger can also be used to exchange heat between the high-temperature fluid flow of pyrolysis products and the hydrocarbon feedstock used in the pyrolysis reactor. This is advantageous because it helps to preheat the hydrocarbon feedstock before it is fed into the pyrolysis reactor, thereby improving the overall energy efficiency of the chemical system.

[0031] Depending on the intended use of the treated hydrogen, its final parameters can be adjusted. In many cases, it is desirable to deliver the treated gas from the chemical system at a higher temperature. Therefore, the heat exchanger can be configured to increase the temperature of the gas stream using the treated hydrogen as the working fluid, thereby achieving a high gas temperature above 300°C or even above 700°C.

[0032] Many types of heat exchangers can be used in the chemical system of this invention. In a preferred embodiment, the heat exchanger is a countercurrent heat exchanger. Alternatively, other typical working fluids can be used during operation. For example, the heat exchanger can exchange heat between a high-temperature fluid flow of pyrolysis products and at least one heat exchange fluid selected from more common working fluids or components, such as air, steam, molten metal, molten salt, and water.

[0033] The chemical methods and chemical systems of the present invention are described in detail below with reference to the accompanying drawings. Attached Figure Description

[0034] Figure 1AThis is a schematic diagram of a chemical system according to the present invention for obtaining treated hydrogen at high gas temperatures.

[0035] Figure 1B yes Figure 1A A partial cross-sectional view of a heat exchanger in a chemical system.

[0036] Figure 2 It is an explanation Figure 1A Flowchart of chemical system operation.

[0037] Figure 3A It is a thermal curve diagram illustrating the heat exchange process between the hot fluid flow and the working fluid flow over a length of 3m in a heat exchanger.

[0038] Figure 3B It is a thermal curve diagram illustrating the heat exchange process between the hot fluid flow and the working fluid flow over a length of 4 m in a heat exchanger.

[0039] Figure 4A An alternative counter-current heat exchanger is shown.

[0040] Figure 4B This is an explanation Figure 4B Cross-sectional view of the interior of the alternative counter-current heat exchanger.

[0041] Figure 5A It shows the use of Figure 1A Cyclone separators in chemical processing systems.

[0042] Figure 5B It shows the use of Figure 1A Candle filters in chemical processing systems.

[0043] Figure 6 This is a schematic diagram of a chemical system used to obtain treated hydrogen at high gas temperatures and to heat hydrocarbon feedstocks. Detailed Implementation

[0044] The accompanying drawings and the following description relate to preferred embodiments of the invention by way of illustration only. It should be noted that alternative embodiments of the structures and methods disclosed in the invention can be readily recognized from the following discussion, and these alternative embodiments can be practiced without departing from the claimed principles of the invention.

[0045] Several embodiments of the present invention will now be described in detail, examples of which are shown in the accompanying drawings. It should be noted that, where feasible, similar or identical reference numerals may be used in the drawings, and similar or identical functions may be represented. The embodiments of the present invention described in the drawings are for illustrative purposes only. Those skilled in the art will readily recognize from the following description that alternative embodiments of the structures and methods shown herein may be employed without departing from the principles described herein.

[0046] Figure 1A This is a schematic diagram of a chemical system 100 according to the present invention. The chemical system 100 is shown in a partial three-dimensional view for clear illustration and presentation.

[0047] The chemical system 100 includes a pyrolysis reactor 102 for pyrolyzing a hydrocarbon feedstock 104, such as primarily or substantially methane or natural gas. Pyrolysis or thermochemical decomposition is also referred to by those skilled in the art as cracking or direct decomposition. In this embodiment, the hydrocarbon feedstock is methane 104 (CH4). Methane 104 is presented in a highly magnified molecular form in a dashed outline.

[0048] It should be noted that the chemical system 100 can use various types of hydrocarbon feedstocks 104, including gaseous, liquid, or solid forms containing one or more hydrocarbons, such as methane, butane, propane, ethane, ethylene, acetylene, propylene, natural gas, liquefied petroleum gas, naphtha, shale oil, wood, biomass, organic waste stream, biogas, gasoline, kerosene, diesel fuel, residual oil, crude oil, carbon black, coal tar, crude coal tar, benzene, methylnaphthalene, polycyclic aromatic hydrocarbons, and other such hydrocarbons. Mixtures of any of the above feedstocks with other hydrocarbon feedstocks, as well as mixtures containing any of these feedstocks with other feedstocks such as methane and nitrogen, methane and carbon dioxide, or methane and carbon monoxide, can be used. A preferred embodiment uses natural gas or a hydrocarbon feedstock primarily composed of methane (CH4) (as in this embodiment).

[0049] Furthermore, it should be noted that the pyrolysis reactor 102 may include a purification system, separation system, or gasification system prior to its pyrolysis stage to purify the hydrocarbon feedstock 104 for decomposition, and to separate and purify the pyrolysis products after the pyrolysis reactor 102. A typical example of pretreatment is the desulfurization of natural gas.

[0050] Many specific types of pyrolysis reactors can be used in chemical system 100. For example, pyrolysis reactor 102 can be a pyrolysis reactor, a microwave pyrolysis reactor, a plasma pyrolysis reactor, a pyrolysis reactor containing liquid metal, a pyrolysis reactor containing liquid salt, and a catalytic pyrolysis reactor. Preferably, pyrolysis reactor 102 is a thermally, plasma-, or microwave-driven reactor in which hydrocarbon feedstock 104 is thermally decomposed.

[0051] The pyrolysis reactor 102 has an inlet 106 for introducing hydrocarbon feedstock 104. Furthermore, the pyrolysis reactor 102 has a top outlet 108 for releasing hydrogen gas 110 (one of the pyrolysis products). At the bottom, the pyrolysis reactor 102 has a bottom outlet 112 for releasing pyrolysis carbon product 114. In this embodiment, the pyrolysis carbon product 114 is solid carbon presented in a highly magnified molecular form within the dashed outline. In practice, the pyrolysis reactor 102 should be configured to decompose the hydrocarbon feedstock 106 into the main solid carbon product 114 and hydrogen gas 110. However, the pyrolysis reactor 102 typically also releases a hydrocarbon fraction 116. The hydrocarbon fraction 116 at the bottom outlet 112 mainly consists of unreacted hydrocarbon feedstock 104 (here, methane (CH4)). Therefore, it... Figure 1A The molecules are also presented in a highly magnified molecular form within the dashed outline. However, more generally, hydrocarbon fraction 116 consists of a variety of hydrocarbons, such as methane, ethane, ethylene, acetylene, and aromatics.

[0052] The pyrolysis-derived hydrogen 110, pyrolysis carbon products or solid carbon products 114, and hydrocarbon fractions 116 together constitute the pyrolysis product 118. In this invention, the most important components of the pyrolysis product 118 are the hydrogen 110 and the solid carbon product 114. Therefore, when pyrolysis product 118 is mentioned herein, it should be understood that it contains at least these most important components. Furthermore, the pyrolysis reactor 102 is preferably operated such that the pyrolysis product 118 is fluidized and discharged together with the solid carbon product 114.

[0053] The pyrolysis reactor 102 is connected to a power source (not shown) to heat the reactor to a high pyrolysis temperature to pyrolyze the hydrocarbon feedstock 104. Specifically, sufficient power is supplied to the pyrolysis reactor 102 to drive the pyrolysis of the hydrocarbon feedstock 104 in an anaerobic environment, wherein preferably, the hydrocarbons are thermochemically decomposed without a catalyst at a temperature ranging from 500°C to 2,000°C. Thus, the pyrolysis product 118 exiting the pyrolysis reactor 102 generates a high-temperature fluid stream 120. Also at such a high pyrolysis temperature, the hydrocarbon feedstock 104 in the form of methane is converted to pyrolysis-derived hydrogen 110 in high yield. In practice, when using methane 104, it is preferable that the pyrolysis reactor 102 maintains the temperature, pressure, and internal conditions to ensure that the hydrogen reaction produces hydrogen 110 at a yield greater than 70%.

[0054] The chemical system 100 has a heat exchanger 122 connected to the pyrolysis reactor 102, such that it receives a high-temperature fluid stream 120 of the pyrolysis products 118 exiting the pyrolysis reactor 102. In this embodiment, the heat exchanger 122 is a countercurrent heat exchanger. More specifically, the countercurrent heat exchanger 122 is a two-tube heat exchanger.

[0055] The heat exchanger 122 has a channel or inner tube 124 for introducing a high-temperature fluid flow 120 of the pyrolysis products 118 through its heat inlet 126. In the case of the heat exchanger, the high-temperature fluid flow 120 of the pyrolysis products 118 is generally referred to by those skilled in the art as a hot fluid. Its high temperature is... Figure 1A The middle is schematically represented by T p,进入 It indicates that the pyrolysis products 118 in the high-temperature fluid flow 120 or the high temperature of the hot fluid entering the inner tube 124 through the hot inlet 126.

[0056] In the design of heat exchanger 122, inner tube 124 is folded twice and terminates at cold outlet 128. A low-temperature fluid flow 130 of pyrolysis products 118 is delivered from the cold outlet 128 of inner tube 124. In other words, heat exchanger 122 cools the high-temperature fluid flow 120 passing through inner tube 124 via heat exchange, detailed below. The low temperature... Figure 1A The middle is schematically represented by T p,排出 It indicates that the low temperature of the pyrolysis products 118 in the low temperature fluid flow 130 or the cold fluid leaving the inner tube 124 through the cold outlet 128 of the heat exchanger 122.

[0057] The heat exchanger 122 has an outer tube or outer pipe 132 that covers or encloses the inner tube 124 along most of its length, forming an annular space or gap around the inner tube 124. For this purpose, the outer tube 132 is also folded twice to match the geometry of the inner tube 124. The outer tube 132 carries the working fluid flow 134 in the opposite direction to the flow of the pyrolysis products 118 through the inner tube 124 from the hot inlet 126 to the cold outlet 128.

[0058] The outer tube 132 has a working inlet 136 for introducing the working fluid flow 134 at low temperatures and a working outlet 138 for releasing the working fluid flow 134 at high temperatures. The high and low temperatures of the working fluid flow 134 at the working inlet 136 and working outlet 138 are also respectively... Figure 1A T w,进入 and T w,排出 Schematic representation. The views of the first and last sections of the outer tube 132, shown in dashed lines, reveal the interior of the working fluid flow 134 in the annular gap surrounding the inner tube 124. This configuration maximizes the temperature difference along the length of the heat exchanger 122 between the hot fluid 120 and the cold fluid or working fluid flow 134, which is crucial for efficient heat transfer.

[0059] To facilitate heat exchange between the hot fluid flow 120 and the cold or working fluid flow 134, the inner tube 124 is typically made of a thermally conductive material. Suitable materials are metals, such as copper, aluminum, stainless steel, ferrochrome, Hastelloy, or polymers with high thermal conductivity. The inner tube 124 may also be made of refractory materials such as graphite, silicon carbide, and alumina. Thus, when the hot fluid flow 120 passes through the inner tube 124, while the cold or working fluid flow 134 passes through the outer tube 132 in the opposite direction, heat is exchanged through the wall of the inner tube 124.

[0060] The chemical system 100 is also equipped with a processing system 140 connected to the heat exchanger 122. The processing system 140 receives a cryogenic fluid stream 130 of the pyrolysis products 118 (i.e., pyrolysis-derived hydrogen 110, solid carbon products 114, and hydrocarbon fractions 116). Because the pyrolysis products 118 are at a low temperature T... p,排出 Its processing ratio through the processing system 140 is higher than that of the high-temperature fluid flow 120 (flowing out from the pyrolysis reactor 102) at a high temperature T. p,进入 The next step is much simpler.

[0061] The processing system 140 has a separator 142 for separating solid carbon products 114. Various types of separators can be used as separator 142 in the processing system 140. For example, separator 142 can be a solids filter, such as a cyclone separator, bag filter, or HEPA filter. In any case, since separator 142 operates at low temperatures, it can operate without any additional high-temperature requirements, as is the case when operating at high temperatures.

[0062] exist Figure 1A In the illustrated embodiment, separator 142 is a bag filter. A collection container 144, located below the bottom outlet 146 of the bag filter 142, is used to collect solid carbon products 114 separated from the pyrolysis products 118 carried in the cryogenic fluid stream 130. Preferably, more than 60% of the solid carbon products 114 are removed or separated from the pyrolysis products 118 by the bag filter 142 to produce a filtered cryogenic fluid stream 130' containing more than 70% hydrogen, presented in a highly magnified molecular form within the shaded dashed outline to distinguish it from the pyrolysis-derived hydrogen 110 obtained from the pyrolysis reactor 106. It should be noted that some hydrocarbon fractions 116 are typically present along with the treated hydrogen 110' in the filtered cryogenic fluid stream 130' exiting the bag filter 142.

[0063] The processing system 140 has a second separator 148 for receiving a filtered cryogenic fluid stream 130' from the bag filter 142, which contains the treated hydrogen 110'. The second separator 148 is preferably a gas filter, such as a pressure swing or temperature swing adsorption system, a distillation system, or a membrane separator. The second separator 148 further purifies the filtered cryogenic fluid stream 130' to remove particulate contaminants, including hydrocarbon fraction 116 and other unwanted particulate matter (not shown). Therefore, the output of the second separator 148 is a purified cryogenic fluid stream 130" of the treated hydrogen 110', which at this point consists primarily of hydrogen.

[0064] Typically, the processing system 140 may be equipped with a number of devices that utilize the cryogenic fluid flow 130 to perform additional useful functions. These additional functions may be performed on the cryogenic fluid flow 130 itself or on the filtered and / or purified cryogenic fluid flow 130', 130" of the processed hydrogen 110'. These include separators beyond the bag filter 142, such as auxiliary systems and devices, to circulate unreacted hydrocarbon feedstock 104 and recirculate heat from the effluent to the influent feedstock. Many such systems are well known to those skilled in the art, and such auxiliary systems may be used in conjunction with the pyrolysis reactor 102. Furthermore, as used herein, the hydrocarbon feedstock 104 includes hydrocarbons that may have been purified, separated, mixed, or otherwise acted upon by auxiliary systems, as described above.

[0065] In this embodiment, the processing system 140 includes a compressor 150 for increasing the pressure of the purified cryogenic fluid stream 130" to suit its downstream applications. Specifically, the compressor 150 increases the pressure of the purified cryogenic fluid stream 130" which consists primarily of treated hydrogen 110" to between 1 and 1,000 bar absolute pressure. After reaching the final pressure in the compressor 150, the purified cryogenic fluid stream 130" (which is primarily an airflow of treated hydrogen 110' at the desired low gas temperature) is prepared to perform a dual function according to the invention.

[0066] First, since the treated hydrogen 110' represents the final product, a gas analyzer 152 is provided in the processing system 140 to measure the chemical composition and purity of the treated hydrogen 110'. This is to ensure that the treated hydrogen 110' meets the requirements of downstream application 154.

[0067] Secondly, since the treated hydrogen 110' is also used as a cold fluid or working fluid flow 134 in the heat exchanger 122, additional conditioning is required before it can be used as a cold fluid or working fluid flow. Specifically, a monitoring or measuring device 156 is provided to generate an airflow of treated hydrogen 110' suitable for use as working fluid flow 134. In its simplest case, device 156 is a measuring device to confirm that the airflow rate of the treated hydrogen 110' is suitable for use and can be properly used as working fluid flow 134. However, preferably, device 156 not only has measuring capability but also the ability to regulate the flow rate to ensure that the airflow of treated hydrogen 110' is indeed suitable for its function as working fluid flow 134 in the heat exchanger 122. Therefore, device 156 may include a final compressor and auxiliary devices, including means for regulating the operation of the first and second separators 142, 148 to ensure that the airflow of treated hydrogen 110' can be used as working fluid flow 134. In fact, device 156 also advantageously controls the operation of compressor 150 to control the absolute pressure of the treated hydrogen 110'.

[0068] Figure 1B A partial plan sectional view of heat exchanger 122 is provided, which better illustrates how, according to the invention, the treated hydrogen gas flow 110' at a regulated flow rate is used as a cold fluid or working fluid flow 134 in heat exchanger 122. For ease of illustration, Figure 1B Several folded sections of heat exchanger 122 are omitted (see...) Figure 1A However, as illustrated, heat transfer occurs between the high-temperature fluid flow 120 of the pyrolysis products 118 and the cold fluid or working fluid flow 134 as they flow past each other in opposite directions. Details of the heat exchange process will be discussed below.

[0069] at the same time, Figure 1B The partial view focuses on key portions of the inner tube 124 and the outer tube 132, which cover or enclose the inner tube 124 to form an annular gap. Specifically, Figure 1B The portion of the inner tube 124, including its hot inlet 126, is shown in detail, wherein the hot fluid (here consisting of a high-temperature fluid flow 120 of pyrolysis products 118) is at a high temperature T p,进入 The fluid is introduced into the inner tube 124. The path of the high-temperature fluid flow 120 is schematically shown, which undergoes two reversals during its passage through the heat exchanger 122.

[0070] Figure 1B The portion of the inner tube 124 with its cold outlet 128 is also shown in detail. As the high-temperature fluid flow 120 passes through the heat exchanger 122, it reaches the cold outlet 128 as a low-temperature fluid flow 130, which is the low-temperature pyrolysis-derived hydrogen 110, solid carbon products 114, and hydrocarbon fractions 116. Specifically, at low temperature T...p,排出 Below, the low-temperature fluid flow 130 of the pyrolysis product 118 leaves the cold outlet 128.

[0071] Figure 1B The portion of the outer tube 132 at the working inlet 136 is shown in further detail, wherein at low temperature T w,进入 Below, a working fluid flow 134, consisting of a treated hydrogen gas stream 110', is introduced into the annular gap between the outer tube 132 and the inner tube 124. The path of the working fluid flow 134 is schematically shown, exhibiting two reversals during its passage through the heat exchanger 122. A portion of the outer tube 132 with a working outlet 138 is also shown in detail for use at high temperature T. w,排出 The working fluid flow 134, consisting of a treated hydrogen gas flow 110', is released below.

[0072] Figure 2 Flowchart 200 explains the operation of chemical system 100 and the heat exchange processes occurring in heat exchanger 122. Flowchart 200 references... Figure 1A The element shown in -B.

[0073] In step 202, hydrocarbon feedstock 104 [methane (CH4) in this embodiment] is fed into pyrolysis reactor 102. It should be noted that methane in natural gas is a low-cost resource that can be obtained from any suitable existing natural gas infrastructure.

[0074] In subsequent step 204, the hydrocarbon feedstock 104 is driven to pyrolyze in pyrolysis reactor 102 under an anaerobic environment. The energy driving the pyrolysis reaction is provided by a power source (not shown). Preferably, the electricity used to drive the pyrolysis reaction comes from grid power or renewable electricity. Renewable energy sources such as hydropower, nuclear power, or wind and solar power with energy storage are advantageous choices for the power source of pyrolysis reactor 102.

[0075] During step 204, the pyrolysis reactor 102 pyrolyzes or treats the hydrocarbon feedstock 104 at a temperature between 500°C and 2,000°C. Therefore, the high-temperature fluid stream 120 of the pyrolysis product 118 conveyed by the pyrolysis reactor 102 exits at its bottom outlet 112 at a temperature between 500°C and 2,000°C. The pyrolysis product 118 thus obtained essentially comprises solid carbon product 114, hydrocarbon fractions 116, and pyrolysis-derived hydrogen 110. It should be noted that the solid carbon product 114 is carried out of the pyrolysis reactor 102 by the high-temperature fluid stream 120, which has a sufficient velocity to fluidize and discharge the solid carbon product 114. Furthermore, it is preferable to operate the pyrolysis reactor 102 to obtain a reaction yield greater than 70% for the conversion of the hydrocarbon feedstock 104 (here, methane) into pyrolysis-derived hydrogen 110.

[0076] Step 204, which involves the pyrolysis of hydrocarbon feedstock 104, can also be carried out in the presence of a catalyst. If step 204 is catalytic, the pyrolysis can occur at temperatures as low as 400°C. However, for higher yields, catalytic pyrolysis of hydrocarbon feedstock 104 is preferably carried out at temperatures exceeding 1,000°C. Therefore, the solid carbon product 114 is not significantly contaminated by the catalytic material. Typically, in catalytic pyrolysis, the decomposition of hydrocarbon feedstock 104 occurs on the surface of the catalyst particles, and the solid carbon product 114 adheres to this surface. When this adhesion occurs, it can lead to catalyst deactivation and / or catalyst loss. If a catalyst is used in step 204, the catalyst should contain a transition metal, such as cobalt (Co), ruthenium (Ru), nickel (Ni), rhenium (Re), platinum (Pt), copper (Cu), tungsten (W), iron (Fe), and molybdenum (Mo), or compounds thereof. The industrial application 154 of the treated hydrogen 110' and solid carbon product 114 produced in the pyrolysis step 204 is in the steel manufacturing embodiment. The catalyst may contain common steel alloying elements such as manganese (Mn), nickel (Ni), chromium (Cr), carbon (C) and vanadium (V) because these elements are often added in subsequent steelmaking to produce different grades of steel.

[0077] When step 204 involves non-catalytic pyrolysis, temperatures exceeding 1,100 °C are typically required to achieve higher yields of conversion of hydrocarbon feedstock 104 into solid carbon products 114 and hydrogen 110. Preferably, temperatures exceeding 1,200 °C and possibly up to 2,000 °C are used in step 204. Further information regarding the thermochemical decomposition parameters of hydrocarbons suitable for use as hydrocarbon feedstock 104 is available in the literature. Here, the reader may refer to M. Wullenkrod's 2012 doctoral dissertation, "Determination of Kinetic Parameters of the Thermal Dissociation of Methane," Lehrstuhl fur Solartechnik (DLR), RWTH Aachen University, and S. Rodat et al., "Kinetic modelling of methane decomposition in tubular solar reactor," Chemical Engineering Journal, 146 (2009), pp. 120-127.

[0078] In the next step 206, the high-temperature fluid stream 120 generated by the pyrolysis in step 204 is conveyed from the pyrolysis reactor 102 to the heat exchanger 122. More precisely, the high-temperature fluid stream 120 is conveyed to the heat exchanger 122 through the hot inlet 126 of the inner tube 124. At this time, the high-temperature fluid stream 120 of the pyrolysis product 118 is at a high temperature T. p,进入 Note that high temperature T p,进入 This typically corresponds to the temperature at which the pyrolysis product 118 leaves the reaction zone of the pyrolysis reactor 102, i.e., between 500°C and 2,000°C.

[0079] Furthermore, in step 206, most (>33%, preferably >90%) of the solid carbon product 114 is fluidized out of the pyrolysis reactor 102 in a high-temperature fluid flow 120. Therefore, the transported pyrolysis product 118 mainly consists of hydrogen 110, solid carbon product 114, and a small amount of hydrocarbon fraction 116 that was not decomposed in the pyrolysis reactor 102. Note that the hydrocarbon fraction 116 typically includes methane as well as ethane, ethylene, acetylene, and aromatics or polycyclic aromatic hydrocarbons. If the high-temperature fluid flow 120 has a sufficient velocity, it will carry particles of the solid carbon product 114 from the pyrolysis reactor 102, enabling continuous operation. However, note that the solid carbon product 114 can also be extracted by means other than fluidization, such as mechanical extraction from the surface of the pyrolysis reactor 102.

[0080] In step 208 (concurrent with step 206), a treated gas stream of hydrogen 110', appropriately regulated to function as either a cold fluid or working fluid stream 134, is delivered to the heat exchanger 122. Specifically, the working fluid stream 134 is delivered into the heat exchanger 122 through the working inlet 136, entering the annular gap between the outer tube 132 and the inner tube 124. The working fluid stream 134 is at a low gas temperature T at the working inlet 136. w,进入 Controlling the low gas temperature T w,进入 The precise value is determined so that the required heat exchange can be achieved between the working fluid flow 134 and the high-temperature fluid flow 120 of the pyrolysis products 118 in the subsequent heat exchange step 210.

[0081] During step 210, heat exchange occurs within heat exchanger 122 between the working fluid flow 134 and the high-temperature fluid flow 120 of the pyrolysis products 118. Preferably, heat exchanger 122 is configured to transfer the high-temperature T of the high-temperature fluid flow 120 to the heat exchanger. p,进入 Lowering the temperature to below 500°C, or even more preferably below 300°C. In other words, the desired low temperature T of the cryogenic fluid flow 130 exiting the pyrolysis products 118 from the cold outlet 128 of the inner tube 124. p,排出Below 500°C, or even more preferably below 300°C. Simultaneously, the heat exchange process in preferred step 210 heats the treated hydrogen gas 110', used as a cold fluid or working fluid flow 134, to a high gas temperature T above 300°C or above 700°C at the working outlet 138. w,排出 .

[0082] To achieve these desired results in step 210, proper construction of the heat exchanger 122 is important. Specifically, according to the invention, the advantageous dual use of the treated hydrogen 110' as a working fluid flow 134 and as a final product of application 154 requires careful balancing of heat exchange conditions. Figure 1A In the preferred embodiment shown in -B, the heat exchanger 122 is used to exchange heat between the pyrolysis products 118 and the treated hydrogen 110' in a counter-current configuration. The key principle of the counter-current heat exchanger 122 is that the two flows 120 and 134 flow in opposite directions. This arrangement allows for efficient heat transfer because the high-temperature fluid flow 120 and the working fluid flow 134 enter the heat exchanger 122 at opposite ends and flow in parallel but opposite directions within the inner tube 124 and the outer tube 132, respectively.

[0083] Heat transfer in the counter-current heat exchanger 122 primarily occurs through conduction via the inner tube 124. Specifically, conductive heat transfer occurs... Figure 1B The diagram is schematically represented by arrow HT passing through the wall portion 124A of the inner tube 124, which is surrounded by the outer tube 132, and through which flows 120 and 134 flow. The secondary heat transfer mechanisms include fluid mixing, turbulence, and convection within each fluid flow 120, 134.

[0084] As the hot fluid flow 120 and the cold fluid or working fluid flow 134 move in opposite directions, they continuously exchange heat energy through the wall portion 124A of the inner tube 124. This exchange causes the hot fluid flow 120 to transfer heat to the working fluid flow 134, resulting in a temperature change between the two flows. The counter-current configuration maintains a temperature gradient along the length of the heat exchanger 122. At the heat inlet 126, the hot fluid flow 120 is at its highest temperature, i.e., T. p,进入 At the working inlet 136, the working fluid flow 134 is at its lowest temperature, i.e., T. w,进入 When flows 120 and 134 are reversed, the temperature of the hot fluid flow 120 decreases, while the temperature of the working fluid flow 134 increases. This results in efficient utilization of the temperature difference, maximizing heat transfer. Therefore, heat exchange step 210 generates a high temperature T from the working outlet 138. w,排出 The treated hydrogen gas 110' is flowed down and a low temperature T is generated from the cold outlet 128. p,排出 The cryogenic fluid flow 130 of the pyrolysis product 118 is below.

[0085] It should be noted that counter-current heat exchange is known for its high thermal efficiency compared to other heat exchange configurations (e.g., co-current or cross-current exchangers). This efficiency is a result of the continuous improvement in the temperature difference between the hot fluid flow 120 and the working fluid flow 134 as they pass through the heat exchanger 122. This is also one of the main reasons why a counter-current geometry is preferred in this invention.

[0086] Figure 3A This is a thermal curve illustrating heat exchange step 210 in a specific case where the wall portion 124A of the inner tube 124 is 3m long, and heat exchange occurs between the hot fluid flow 120 and the working fluid flow 134. Temperature curve 300 shows the temperature of the hot fluid flow 120 from T... p,进入 (1,400℃) significantly decreased to T p,排出 (500℃). Meanwhile, temperature curve 302 shows that the temperature of the working fluid flow 134 changes from T... w,进入 (25℃) significantly increased to T w,排出 (1,000°C). Note that the working fluid flow 134 of the treated hydrogen 110' is compressed.

[0087] The temperature change achieved in step 210 can be increased by increasing the length of the wall portion 124A where heat exchange occurs. In the geometry of the heat exchanger 122, this can be achieved by extending this length through additional folds. Alternatively, the heat exchanger 122 can be lengthened at all three folds.

[0088] Figure 3B This is a thermal curve illustrating heat exchange step 210 when the length of the wall portion 124A of the inner tube 124, where heat exchange occurs between the hot fluid flow 120 and the working fluid flow 134, is extended to 4 m. Temperature curve 304 shows the temperature of the hot fluid flow 120 from T... p,进入 (1,400℃) decreased more significantly to T p,排出 (370℃). Meanwhile, temperature curve 306 shows the temperature of the working fluid flow 134 from T... w,进入 (25℃) rose more significantly to T w,排出 (1,100°C). Note again that the working fluid flow 134 of the treated hydrogen 110' is compressed.

[0089] A significant benefit of this invention is that the thermal mass of the pyrolysis product 118 in the hot fluid flow 120 is approximately the same as the thermal mass of the treated hydrogen 110' in the working fluid flow 134. This makes heat transfer between fluid flows 120 and 134 highly efficient. Figure 3AThe thermal profile of -B shows that the treated hydrogen 110' in the working fluid stream 134 can easily reach temperatures exceeding 1,000°C. Such temperatures are highly desirable when application 154 is iron ore reduction. Another benefit of the invention is that cooling the pyrolysis products 118 in the hot fluid stream 120 to temperatures below 1,000°C should effectively quench or stop the thermal decomposition reaction, thereby preventing any unreacted hydrocarbons leaving the pyrolysis reaction from decomposing in downstream components of the processing system 140 and leaving behind difficult-to-clean carbon deposits.

[0090] return Figure 2 Following flowchart 200, we proceed to step 212, where the treated cryogenic fluid stream 130 of the pyrolysis product 118 (at a cryogenic temperature below 500°C or even below 300°C) p,排出 It is transferred to the processing system 140. Because of the low temperature T p,排出 With high temperature T p,进入 (Potentially as high as 2,000°C) Compared to this, step 212 is significantly reduced, and step 212 is greatly simplified. This is because at low temperatures T p,排出 The transport and handling of cryogenic fluids 130 (especially the transport and handling of pyrolysis products 118 of their components at this cryogenic temperature) does not require cumbersome high-temperature equipment.

[0091] The subsequent step 214 (separation of solid carbon product 114) is carried out on a cryogenic fluid stream 130 within the processing system 140. Step 214 preferably involves using a separator 142 to remove most of the solid carbon product 114. Preferably, more than 60% of the solid carbon product 114 is removed in step 214 to produce a filtered cryogenic fluid stream 130' containing treated hydrogen gas 110' with more than 70% hydrogen content.

[0092] In step 216, the filtered cryogenic fluid stream 130' is passed to the second separator 148 (gas filter). Step 216 involves purifying the filtered cryogenic fluid stream 130' to remove particulate contaminants, including hydrocarbon fractions 116 that are still present at this point. Therefore, the output of step 216 is a purified cryogenic fluid stream 130" of treated hydrogen 110', which at this point consists primarily of hydrogen.

[0093] In step 218, the purified cryogenic fluid stream 130" is adjusted for its dual purpose: as a flow of treated hydrogen 110" in the working fluid stream 134 of the heat exchanger 122, and also as a final product. During step 218, the compressor 150 increases the pressure of the purified cryogenic fluid stream 130". Preferably, the actual absolute pressure is adjusted so that the thermal mass of the purified cryogenic fluid stream 130" closely matches the thermal mass of the hot fluid stream 120 of the pyrolysis product 118. Furthermore, the apparatus 156 adjusts the flow rate of the purified cryogenic fluid stream 130" to achieve the desired residence time in the heat exchanger 122, thereby achieving the desired level of heat exchange with the hot fluid stream 120. Figure 3A In the embodiment shown in -B, the flow rates of the two fluid flows 120 and 134 are 50 kg-H2 / day, which is approximately equivalent to 210 SLMP (standard liters per minute). The pressure of the hot fluid flow 120 entering the heat exchanger 122 is approximately 15 psi, while the pressure of the working fluid flow is approximately 450 psi.

[0094] In step 218, the chemical composition of the purified cryogenic fluid stream 130" of the treated hydrogen 110" is also examined. The chemical composition is important for application 154. Preferably, the device 156 regulates the operation of separators 142, 148 of the processing system 140 to achieve the desired chemical composition. In fact, other components, including auxiliary filters, may be present in the processing system 140 to help control the chemical composition of the purified cryogenic fluid stream 130".

[0095] Once the chemical composition, flow rate, and pressure are properly adjusted, the cryogenic fluid flow 130" of the treated hydrogen 110" is transferred from step 218 to step 208. As described above, in step 208, the cryogenic fluid flow 130" is treated as if at a low temperature T w,进入 The working fluid flow 134 is processed at a temperature of 25°C (for example, in this embodiment).

[0096] Flowchart 200 also shows that the high-temperature treated hydrogen gas 110' exits at the working outlet 138 of the outer tube 132 of the heat exchanger 122. At this time, the treated hydrogen gas 110' is at a high temperature T. w,排出 (For example, depending on the length of the wall portion 124A where heat exchange occurs, it is 1,000°C or even 1,100°C).

[0097] In step 220, the hot, treated hydrogen 110' is delivered to application 154. The high-temperature treated hydrogen 110' has many industrial applications. The desired delivery purity, pressure, and temperature of the treated hydrogen 110' will vary depending on the specific application 154. Accordingly, these parameters are adjusted in the treatment system 140 when application 154 is specified.

[0098] Table 1 below shows the different industrial sectors where treated hydrogen 110' can be used and the desired delivery purity, pressure, and temperature.

[0099] Table 1.

[0100] Regarding delivery purity, low, medium, and high purity refer to approximately 80-95%, 95-99.5%, and 99.5-99.999% hydrogen content in treated hydrogen 110', respectively. Low, medium, and high delivery pressures are approximately 1-2 bar, 2-100 bar, and 100-1000 bar, respectively. Low, medium, and high delivery temperatures are approximately 0-50°C, 50-400°C, and >400°C, respectively. These values ​​are for reference only; treated hydrogen 110' can be used in any field at any purity, pressure, and temperature as required.

[0101] To make the treated hydrogen 110' suitable for industrial applications 154 (e.g., steelmaking, chemical production, fuel, or heating), some or all of the solid carbon products 114 need to be separated in the separator 142 of the treatment system 140. For steelmaking applications 154, it may be desirable to introduce a relatively large proportion of solid carbon products 114, up to 50%, into the ironmaking process for carburizing. Therefore, for such applications 154, the separator 142 of the treatment system 140 should not separate more than 50% of the solid carbon products 114.

[0102] However, for most other applications 154 of the treated hydrogen 110, it is desirable that the separator 142 of the treatment system 140 remove the vast majority of solid carbon products 114 from the pyrolysis gas 118. Note that the separation of solid carbon products 114 is generally critical to minimizing the formation of carbon dioxide from the chemical system 100. A portion of the solid carbon products 114 will be fluidized out of the pyrolysis reactor 102 along with the pyrolysis products 118, as the drag force is sufficient to overcome the weight of the particles, allowing them to be carried by the high-temperature fluid stream 120. If the gas remains at a high temperature in downstream processing, it is necessary to remove the carbon and other gaseous components present in the high-temperature fluid stream 120 at high temperatures to purify the hydrogen 110, which, as mentioned above, is difficult.

[0103] It should be noted that Figure 2 Flowchart 200 illustrates the operation of a chemical system 100 that is already in operation. In the case of a cold start of the chemical system 100, pre-stored compressed hydrogen or an inert gas, such as N2 or argon, can be used during the start-up phase before the processes shown and described in flowchart 200 are run.

[0104] The chemical system and method of the present invention allow for various alternative implementations. In particular, different types of countercurrent heat exchangers can be used instead of the heat exchanger 122 with the above-described dual-tube geometry.

[0105] Figure 4A An alternative countercurrent heat exchanger 400, which may be used in chemical system 100 or an alternative embodiment, is shown. The heat exchanger 400 is a shell-and-tube heat exchanger. The heat exchanger 400 has a shell 402 with a hot inlet 404 for introducing a hot fluid flow 406 and a cold outlet 408 for conveying a cold fluid flow 410. The heat exchanger 400 also has a working inlet 412 for introducing a working fluid flow 414 and a working outlet 416 for discharging a working fluid flow 418. Line A indicates... Figure 4B A cross-sectional cut of the heat exchanger 400 shown in view through the housing 402.

[0106] Figure 4B The internal geometry of the shell 402 is shown, in which the hot fluid flow 406 entering through the hot inlet 404 is distributed into a plurality of tubes 422. Thus, in the counter-flow shell-and-tube heat exchanger 400, the hot fluid flow 406 flows through the tubes 422, while the working fluid flow 414 flows in the opposite direction through the outside of the tubes 422 inside the shell 402. Figure 4B The area specified by reference numeral 420 in the attached figure.

[0107] In the case of heat exchanger 122, it is preferable to allow the high-temperature fluid flow 120, consisting of the lower-pressure pyrolysis products 118, to pass through the inner tube 124, as discussed and shown above. One of the main reasons for this is that such a configuration reduces the cooling and insulation requirements for the outer tube 132. This is because even at the working outlet 138, its high temperature T is reached. w,排出 The treated hydrogen gas 110' will still be at a higher temperature than the pyrolysis products 118, at a higher temperature T of 120. p,进入 Lower temperatures (potentially up to 2,000°C) are also possible. This is also true when using a shell-and-tube heat exchanger 400. Therefore, it is also preferable that the hot fluid flow 406 is surrounded by a reverse working fluid flow 414 in the region 420 within the shell 402 while passing through the tube 422.

[0108] However, in some embodiments, it is preferable that the working fluid flow 134 of the treated hydrogen 110' at a lower temperature and higher pressure flows inside the inner tube 124, or inside the tube 422. This is done to maintain tensile stress on the inner tube 124, or inside the tube 422, as their cross-sectional area can be easily designed to be smaller than the annular area of ​​the outer tube 132 or the shell 402. This design allows the treated hydrogen 110' at higher pressure and the pyrolysis product 118 at lower pressure to have similar mass flow rates. Ultimately, the preferred heat exchanger design and geometry will depend on the temperature and pressure of the pyrolysis product 118 and the desired temperature and pressure of the treated hydrogen 110'. Note that these temperatures and pressures will be different for each application 154. For any given chemical system of the present invention, the appropriate adjustment of the most suitable heat exchanger design will be well known to those skilled in the art.

[0109] In another embodiment, a plate heat exchanger may be employed in chemical system 100 or in another embodiment of the chemical system of the present invention. The advantage of using plates is that the hot and cold fluid flows are exposed over a larger area because they are spread out on the plates. This facilitates the heat transfer process and also significantly increases the rate of temperature change as the fluids pass in opposite directions.

[0110] The chemical system and method of the present invention also have further variations and modifications based on application 154 and its requirements. In the present invention, pyrolysis product 118 refers to hydrogen 110, solid carbon product 114, and hydrocarbon fraction 116, which may include various gases and carbon particles leaving the pyrolysis reaction zone of the pyrolysis reactor 102 where the pyrolysis reaction takes place. Pyrolysis product 118 is processed in processing system 140 to obtain processed hydrogen 110', which refers to a gas stream primarily containing hydrogen but may also contain unreacted hydrocarbon gases (e.g., methane, ethane, ethylene, acetylene, and benzene) and solid carbon particles. However, such a composition is practically desirable for application 154. For example, when processed hydrogen 110' is used as a reducing agent or for chemical production, residual methane in processed hydrogen 110' is acceptable or sometimes considered inert. In these applications, acceptable residual hydrocarbon fraction 116 can be up to 20%. However, in many applications, it is preferable to reduce this residual hydrocarbon fraction 116 as much as possible, particularly when it is desirable to minimize carbon dioxide emissions. Similarly, residual solid carbon particles in the treated hydrogen 110' can be acceptable, up to >40% by mass of the original carbon produced by pyrolysis. However, it is generally preferred to remove solid carbon from the pyrolysis products 118, thereby obtaining treated hydrogen 110' that can be used to avoid the formation of carbon dioxide emissions. Furthermore, the treated hydrogen 110' can optionally be compressed to the desired delivery pressure using a compressor.

[0111] In other embodiments, the processing system 140 may employ different types of separators. For example, such as Figure 5A The cyclone separator 500 shown can be used to separate solid carbon products 114 and carbon particles from a cryogenic fluid flow 130 containing pyrolysis products 118. The design of a cyclone separator 500 for gas-solid separation is well known in the art. Specifically, the pyrolysis products 118, including solid carbon products 114, enter the cyclone separator 500 through the inlet 502. Inside the cyclone separator 500, the pyrolysis products 118 rotate around a central outlet pipe 504 at a lower pressure, as shown. Most of the solid carbon products 114 fall through the outlet 506 at the bottom of the cyclone separator under gravity. The remaining gas containing the pyrolysis products 118 is discharged upwards through the central outlet pipe 504. The diameters of the cyclone separator inlet 502 and outlet pipe 504, as well as the pressure drop through the cyclone separator 500, are key parameters determining the separation efficiency. Efficiency in this case is an indicator of the efficiency of separating solid particles from the gas flow. Generally, larger particles are easier to separate than smaller particles. A series of cyclone separators can be used to ensure the separation of most of the solid carbon products 114. Cyclone separator design parameters and their optimization are well known to those skilled in the art.

[0112] It should be noted that in the prior art, a high-temperature cyclone separator is required to maintain hydrogen 110 at a high temperature. Such a high-temperature cyclone separator requires good insulation and a refractory lining to maintain the pyrolysis gas at a temperature >900°C. All pipes require refractory linings to transport pyrolysis gas and carbon at high temperatures, increasing complexity. One challenge of using a cyclone separator at high temperatures is that solid carbon particles abrade the refractory surface and cause degradation over time. Clearly, the present invention has the advantage of operating on a low-temperature fluid flow 130 of the pyrolysis products 118, thereby avoiding these high-temperature challenges.

[0113] The processing system 140 can also adopt, for example Figure 5BThe candle filter 600 shown is used to separate solid carbon products 114. The candle filter 600 is a filtration device that uses a cylindrical filter element 602 [commonly referred to as a candle wick] to remove impurities and particles from a cryogenic fluid flow 130 of pyrolysis products 118. The candle wick 602 is typically composed of a porous media (e.g., ceramic, metal, or polymer) that allows the cryogenic fluid flow 130 to pass through while trapping solid particles (e.g., solid carbon products 114 or contaminants). The candle wick 602 is vertically arranged within a housing 604, and the cryogenic fluid flow 130 of the pyrolysis products 118 to be filtered enters the candle filter through inlet 606. It then passes through the candle wick 602 from the outside in, causing contaminants (in this case, solid carbon products 114) to be trapped on the outer surface of the candle wick 602. Meanwhile, the remainder of the cryogenic fluid flow 130 of the pyrolysis products 118 exits the candle filter 600 through outlet 608.

[0114] Trapped particles accumulate on the surface of the wick 602, forming a filter cake, which can be removed periodically by cleaning or replacing the wick 602. Candle filters are commonly used in various industrial applications, including wastewater treatment, chemical processing, and pharmaceutical production, due to their high efficiency, low maintenance, and cost-effectiveness. The maximum operating temperature of the candle filter 600 depends on the material of the filter element and the type of fluid or gas being filtered. For example, ceramic candle filters can typically operate at temperatures up to 900-1,000°C. To operate at temperatures >900°C, ceramics such as silicon carbide are preferred. However, the maximum temperature can be limited by the design of the housing 604 and the seals used, which may not withstand extreme temperatures. Furthermore, some fluids or gases may contain components that corrode or erode the filter element 602, thereby reducing its effectiveness or causing premature failure.

[0115] Candle filters have several limitations that make their use challenging. The filter cake that forms on the wick surface can cause pressure drops and reduced flow rates, potentially requiring frequent cleaning or replacement of the filter element. Cleaning is typically performed using a reverse gas pulse system. Operating a reverse gas pulse in a high-temperature environment containing hydrogen (110°C) is challenging due to the requirements on the construction materials needed to prevent combustion or explosion in the hydrogen-containing gas environment for safe operation. An inert or hydrogen gas pulse is required, which dilutes and cools the pyrolysis product stream. Most high-temperature ceramic or metal candle filters are less effective than low-temperature (<250°C) polymer candle filters or bag filters in removing very small particles (<1-5 μm) that may be present in the pyrolysis product stream. Candle filters may not be suitable for fluids or gases containing high concentrations of solids, as this can rapidly clog the filter element. Finally, candle filters can be more expensive than other types of filtration devices, especially in applications requiring high-temperature or corrosion-resistant materials.

[0116] Clearly, handling pyrolysis gases at high temperatures presents challenges for further purification and compression. Therefore, again, the present invention has the advantage of operating on a cryogenic fluid flow 130 of the pyrolysis products 118, thus avoiding the high-temperature challenges. The invention further focuses on utilizing the thermal energy in the pyrolysis products 118 while simultaneously achieving purification and compression, so that the gases produced by pyrolysis are suitable for industrial applications 154, such as process heat, transportation, chemical production, and chemical reduction.

[0117] Figure 6 This is a schematic diagram of a chemical system 700 employing a pyrolysis reactor 702 containing liquid metal, according to another embodiment. For clarity, similar parts and elements in this embodiment are referred to using the previously used reference numerals.

[0118] The pyrolysis reactor 702 has an outlet 704 for releasing a high-temperature fluid stream 120 of pyrolysis products 118. The pyrolysis products 118 mainly consist of pyrolysis-derived hydrogen 110, pyrolysis carbon products or solid carbon products 114, and hydrocarbon fractions 116. Furthermore, it is preferable to operate the pyrolysis reactor 702 such that the solid carbon products 114 are fluidized and discharged from the pyrolysis reactor 702 together with the pyrolysis products 118, as in the aforementioned embodiments.

[0119] The chemical system 700 has a first heat exchanger 706 and a second heat exchanger 708 arranged in series. Both heat exchangers 706 and 708 are counter-current type. Furthermore, it is configured such that a high-temperature fluid flow 120 of the pyrolysis product 118 passes through the first heat exchanger 706 and then through the second heat exchanger 708. Therefore, a low-temperature fluid flow 130, or cold fluid, flows out from the second heat exchanger 708.

[0120] The cryogenic fluid flow 130 of the pyrolysis product 118 is transferred from the second heat exchanger 708 to the processing system 710. As in the aforementioned embodiments, the processing system 710 may employ various devices and components (not explicitly shown). In particular, the processing system 710 has a separator for separating solid carbon products 114 and a gas filter for removing hydrocarbon fractions 116 and any other undesirable contaminants. Furthermore, the processing system 710 has a compressor and other devices for delivering treated hydrogen gas 110', preferably containing more than 70% hydrogen, which is presented in a highly magnified molecular form within the shaded dashed outline to distinguish it from the pyrolysis-derived hydrogen gas 110 obtained from the pyrolysis reactor 702 containing liquid metal.

[0121] Again, according to the invention, the treated hydrogen 110' serves a dual purpose. It is used as the working fluid flow 134 in the first heat exchanger 706 to cool the high-temperature fluid flow 120 of the pyrolysis products 118. It is also the final product transported from the heat exchanger 706 to the application 154.

[0122] In this application, the cryogenic gas stream of treated hydrogen 110' is used as the working fluid stream 134 in the first heat exchanger 706. Its cryogenic temperature is T. w1,进入 Its high temperature or the temperature at which it is transported to the application is 154T. w1,排出 The heat exchange configuration between the working fluid flow 134 within the first heat exchanger 706 and the high-temperature fluid flow 120 of the pyrolysis products 118 is such that the high temperature of the high-temperature fluid flow 120 is reduced to below 500°C, or even more preferably below 300°C. In other words, the desired low temperature of the high-temperature fluid flow 120 leaving the first heat exchanger 706 is below 500°C, or even more preferably below 300°C. As described in the above embodiment, this can be achieved by maintaining a low temperature T... w1,进入 (Approximately 25°C) enters the first heat exchanger 706 and is then subjected to high temperature T. w1,排出 The working fluid flow 134 exits at (1,000°C or even higher) to achieve this.

[0123] The chemical system 700 uses a second heat exchanger 708 to further cool the high-temperature fluid stream 120. In other words, the second heat exchanger 708 is designed to further reduce the temperature of its output low-temperature fluid stream 130 to below 300°C, and preferably even below 200°C. This is achieved by using a stream 712 of hydrocarbon feedstock 104 as the working fluid in the second heat exchanger 708. Stream 712 originates from a source of hydrocarbon feedstock 104 (not shown) and is appropriately regulated for its function as a working fluid (flow rate and pressure regulation).

[0124] Using the hydrocarbon feedstock 104 stream 712 as the working fluid in the second heat exchanger 708 has two advantages. First, since the hydrocarbon feedstock 104 is typically at a low temperature T w2,进入 (At or below 25°C) it is therefore well-suited for further cooling the high-temperature fluid stream 120 to below 200°C. Secondly, preheating the hydrocarbon feedstock 104 in the second heat exchanger 708 before pyrolysis in the pyrolysis reactor 702 is energy-efficient. At a high temperature T approaching 300°C... w2,排出 The preheated hydrocarbon feedstock 104' requires less energy input to reach the desired pyrolysis temperature in the pyrolysis reactor 702 to drive pyrolysis. The preheated hydrocarbon feedstock 104' is then fed to the inlet 714 of the pyrolysis reactor 702, where it... Figure 6 The molecules within the shaded dashed outline are shown in highly magnified form to distinguish them from the cold hydrocarbon feedstock 104. It should be noted that more than one heat exchanger may be used to exchange heat between the pyrolysis products 118 and the stream 712 of hydrocarbon feedstock 104.

[0125] Lowering the temperature of the pyrolysis products 118 in the cryogenic fluid stream 130 to below 200°C has many advantages. At such low temperatures, low-cost elastomeric seals can be used between components in any part of the processing system 710. In alternative variations or embodiments of the chemical system 700, more heat exchangers can be added in series when further temperature reduction is required. Such additional heat exchangers can use air, steam, water, molten metal, or salt as working fluids to further cool the pyrolysis products 118. Indeed, in this alternative embodiment, heat exchangers in series can be used to exchange heat between the pyrolysis products 118 and the flow of treated hydrogen 110'. Heated air, water, steam, molten metal, or salt are known to those skilled in the art for a variety of applications, including but not limited to Rankine cycles for generating energy from waste heat, steam turbines for power generation, and boilers for process heat or district heating.

[0126] Another advantage of using the first heat exchanger 706 in series with the second heat exchanger 708 is that stainless steel pipes can be used to transport the pyrolysis products 118 once they have cooled to below 760°C (i.e., after leaving the first heat exchanger 706). However, temperatures below 400°C are preferred before using pipes made of a material containing a catalytic material. It will be apparent to those skilled in the art that the order of any heat exchangers can be interchanged to change the temperature of the pyrolysis products 118 and the heat exchange flow at the inlet and outlet of each heat exchanger. For example, in an alternative embodiment, a steam-jacketed heat exchanger can be used as the first heat exchanger 706 at the outlet 704 of the pyrolysis reactor 702 to reduce the temperature of the pyrolysis products 118 to <1,100°C and generate superheated steam, while maintaining the heat exchanger walls at a temperature where common metal-based structural materials can be used. Downstream, another heat exchanger can be used to exchange heat between the pyrolysis products 118 at 1,100°C and the treated hydrogen gas 110'. This implementation is preferred if the treated hydrogen stream 110' does not need to reach a temperature >1,000°C. However, if a temperature >1,000°C is required, it is preferable to first use a first heat exchanger 706 to exchange heat between the pyrolysis product 118 and the treated hydrogen stream 110', and then use an additional heat exchanger downstream after the pyrolysis product 118 has been cooled by the first heat exchanger 706.

[0127] Now that the pyrolysis product 118 has cooled, it is easier to form a seal between any processing equipment and to use common piping materials such as stainless steel, copper, and aluminum. Therefore, processing system 710, as well as any auxiliary or additional systems that cannot be used due to high temperatures, can now be employed as part of or additional to processing system 710. These alternative embodiments implemented by the present invention are described below.

[0128] In processing system 710, carbon particles are removed from pyrolysis product 118 to achieve the desired hydrogen purity by using any of the separation devices and methods described above (e.g., cyclone separation, electrostatic precipitation, bag filtration, mechanical filtration with screens and mesh, wet, dry, and venturi scrubbers, and pneumatic separation). Importantly, very small carbon particles can be removed from the stream of pyrolysis product 118 using a high-efficiency particulate air (HEPA) filter. HEPA filters are designed to capture particles as small as 0.3 micrometers (μm) with an efficiency of at least 99.97%. While high-temperature ceramic filters exist, most HEPA filters are made of dense, randomly arranged fiber webs or pads made of materials such as glass fiber, paper, or synthetic materials, which are unstable at high temperatures. Therefore, the present invention enables the use of fine particle filtration. Particle filtration methods at temperatures below 300°C, and particularly below 200°C, are well known to those skilled in the art, and it will be apparent that the desired composition of pyrolysis product 118, separation of solid carbon product 114, and solid removal can be achieved using any of the methods described above, or in combination with other methods.

[0129] In another embodiment of the invention, which achieves cryogenicity, various solid purification processes can be used to further purify the solid carbon product 114. Suitable purification processes include hydrometallurgical processes, such as filtration, centrifugation, flotation, precipitation, and sedimentation; mechanical processes, such as sieving, magnetic separation, electrostatic separation, and air separation; and thermal processes, such as evaporation and sublimation; and chemical processes, such as leaching. Using solid purification processes can be advantageous to produce more commercially viable products requiring low contamination or specific particle sizes. In cases where the solid carbon product 114 is contaminated with molten salts or metals, purification may be necessary for safe disposal. Such solid purification processes are well known to those skilled in the art, and it will be apparent to them that purified solid carbon product 114 can be achieved using or in combination of any of the foregoing methods or processes, as well as other methods or processes. In yet another embodiment, the solid carbon purification process employs a thermal purification process, wherein at least a small fraction (>10%) of the required thermal energy is provided by exchanging heat from the pyrolysis product 118 using a heat exchanger.

[0130] In many applications of hydrogen, it is desirable to remove hydrocarbons (e.g., methane, ethane, ethylene, acetylene, and benzene) from the pyrolysis product 118 to obtain a substantially pure stream of treated hydrogen 110'. Furthermore, it is generally preferred to remove sulfur-containing compounds, such as hydrogen sulfide, sulfur dioxide, and sulfides, from the pyrolysis product 118. Pressure swing adsorption (PSA) is the most commonly used industrial gas separation method, in which gases are selectively adsorbed and desorbed on a solid adsorbent using varying pressure levels, thereby allowing the separation of different gases. PSA can effectively purify pyrolysis products to achieve hydrogen purity exceeding 99%. In other embodiments, other gas separation methods, such as absorption, distillation, cryogenic distillation, membrane separation, temperature swing adsorption, chemisorption, washing, and catalytic conversion, are used to purify the pyrolysis product 118 to obtain a purified stream of treated hydrogen 110'.

[0131] In another embodiment, the pyrolysis product 118 is compressed in a compressor to obtain treated hydrogen 110' at the desired delivery pressure. The compressor draws in a low-pressure gas (e.g., pyrolysis product 118 or purified and treated hydrogen 110') at its inlet and then uses mechanical energy to reduce the volume of the gas, thereby increasing its pressure. The compressed gas is discharged at a pressure higher than the inlet pressure. The main types of gas compressors include: (1) positive displacement compressors, (2) dynamic compressors or turbo compressors, (3) jet compressors, (4) scroll compressors, and (5) liquid ring compressors. (1) Positive displacement compressors operate by capturing a fixed amount of gas in a chamber and then reducing the volume of that chamber to compress the gas. There are two main types: reciprocating and rotary screw. Reciprocating compressors use a piston and cylinder mechanism to compress the gas. They are typically used in low to medium pressure applications and are suitable for intermittent operation. Rotary screw compressors use a rotating screw to capture and compress the gas and are known for their continuous and efficient operation. (2) Dynamic compressors, also known as turbo compressors, operate by imparting kinetic energy to a gas and then converting it into pressure energy. There are two main types: centrifugal and axial. Centrifugal compressors use a rotating impeller to accelerate the gas to high speed, and then the kinetic energy is converted into pressure as the gas passes through a diffuser. Axial compressors have a series of rotating and stationary blades that compress the gas in a continuous flow. (3) Jet compressors use a high-speed gas jet to entrain and compress another gas. They are typically used in applications where there are specific requirements for mixing gases or creating a vacuum. (4) Scroll compressors use two helical scrolls (one stationary and one rotating) to compress the gas. (5) Finally, liquid ring compressors use a rotating impeller in a liquid ring to compress the gas. They are typically used in applications requiring a pulsation-free flow. Different types of compressors, sizes, and arrangements, including multiple compressors in series or parallel, will be optimized based on the application 154 and its desired pressure and temperature for compressing the treated hydrogen 110'. The type of compressor and its arrangement suitable for each application are well known to those skilled in the art.

[0132] A significant advantage of compressing the pyrolysis product 118 downstream of the pyrolysis reactor 702 is that the reactor does not need to be operated under high pressure. In many industrial chemical applications, operating the pyrolysis reactor 702 under high pressure is advantageous because it can increase reaction yield or rate, such as in ammonia synthesis. However, in methane pyrolysis, the reaction yield decreases with increasing pressure, according to Le Chatelier's principle, due to the production of more moles of gas in the reaction. Therefore, from a yield perspective, operation at pressures close to atmospheric pressure is desirable. Furthermore, operation at near atmospheric pressure means that the pyrolysis reactor 702, regardless of type, including the furnace, does not need to be a pressure vessel or be housed within one, which increases engineering complexity.

[0133] Another benefit of this invention is that by cooling the pyrolysis products 118 before compression, a wider range of compressors can be used. Compressing gases at high temperatures is difficult, especially above 300°C, because seals, coolants, lubricants, and construction materials become more challenging. At high temperatures, jet compressors may be necessary, where the gas is compressed by the inertial force of another gas rather than a solid or liquid medium.

[0134] In some embodiments, the treated hydrogen gas 110', which has been purified and compressed, is analyzed or measured before being delivered to application 154 (e.g., an industrial process). For example, the flow rate of the treated hydrogen gas 110' is measured using a flow meter. The flow meter can be selected from various types, such as orifice plates, venturi tubes, rotor flow meters, thermal mass flow meters, differential pressure flow meters, ultrasonic flow meters, vortex shedding flow meters, Coriolis flow meters, turbine flow meters, volumetric flow meters, and derivatized flow meters. In some embodiments, the chemical composition and purity of the treated hydrogen gas 110' are analyzed. Examples of gas analysis techniques that can be used in this invention include: gas chromatography, mass spectrometry, infrared spectroscopy, ultraviolet-visible spectroscopy, flame ionization detector coupled with mass spectrometry, thermal conductivity detection, photoionization detection, gas sensors, and gas analyzers.

[0135] Finally, regarding particulate matter removal, gaseous or solid carbon purification, gaseous or solid measurement, and compression equipment, processes, and systems, we note that these are well known to those skilled in the art. Therefore, it will be apparent to those skilled in the art that any of the foregoing equipment, methods, or systems, as well as other equipment, methods, or systems, can be used or combined to obtain treated hydrogen gas 110' in a stream with a temperature <300°C or more preferably below 200°C. Importantly, it will be apparent to those skilled in the art that additional particulate matter removal, gas purification, and compression methods, as well as other gas treatment and measurement processes and equipment not explicitly stated herein, can be used to achieve the treated hydrogen gas stream as described herein. For example, process gas blowers and fans are suitable additional equipment and process apparatuses for treating the treated hydrogen gas stream described herein.

[0136] It will be apparent to those skilled in the art that the present invention allows for a variety of other embodiments. Therefore, its scope should be determined by the claims and their legal equivalents.

Claims

1. A chemical system for producing treated hydrogen at high gas temperatures, the chemical system comprising: a) A pyrolysis reactor used to pyrolyze hydrocarbon feedstocks to produce a high-temperature fluid stream of pyrolysis products, which mainly contain hydrogen and solid carbon products. b) A heat exchanger connected to the pyrolysis reactor for receiving a high-temperature fluid flow of the pyrolysis products and conveying a low-temperature fluid flow of the pyrolysis products; c) A processing system, connected to the heat exchanger, for: 1) The cryogenic fluid stream receiving the pyrolysis products; 2) Process the pyrolysis products to obtain the processed hydrogen at a low gas temperature; 3) The gas stream of the treated hydrogen at the low gas temperature is fed to the heat exchanger; The heat exchanger exchanges heat between the high-temperature fluid flow of the pyrolysis products and the gas flow of the treated hydrogen at the low gas temperature to cool the high-temperature fluid flow and heat the gas flow at the low gas temperature, thereby producing the treated hydrogen at the high gas temperature.

2. The chemical system of claim 1, wherein the hydrocarbon feedstock substantially comprises methane or natural gas, and the solid carbon product comprises solid carbon.

3. The chemical system of claim 1, wherein the pyrolysis reactor pyrolyzes the hydrocarbon feedstock at a temperature between 500°C and 2,000°C.

4. The chemical system of claim 1, wherein a portion of the solid carbon product is fluidized out of the pyrolysis reactor via the high-temperature fluid flow of the pyrolysis products.

5. The chemical system of claim 1, wherein the processing system includes a separator for separating more than 60% of the solid carbon products from the cryogenic fluid stream of the pyrolysis products to produce the processed hydrogen containing more than 70% hydrogen.

6. The chemical system of claim 5, wherein the separator comprises a solid filter selected from the group consisting of a cyclone separator, a bag filter, and a HEPA filter.

7. The chemical system of claim 5, wherein the separator comprises a gas filter selected from the group consisting of pressure swing or temperature swing adsorption systems, distillation systems, and membrane separators.

8. The chemical system of claim 1, wherein the processing system further comprises at least one device selected from: 1) A compressor for increasing the pressure of the cryogenic fluid flow to between 1 and 1,000 bar absolute pressure; 2) A measuring device for measuring the flow rate of the gas stream of the treated hydrogen at the low gas temperature; and 3) A gas analyzer for measuring the chemical composition and purity of the treated hydrogen at the low gas temperature.

9. The chemical system of claim 1, wherein the heat exchanger is configured to reduce the temperature of the high-temperature fluid flow of the pyrolysis products to below 500°C or below 300°C.

10. The chemical system of claim 1, wherein the heat exchanger further exchanges heat between the high-temperature fluid flow of the pyrolysis product and the hydrocarbon feedstock.

11. The chemical system of claim 1, wherein the heat exchanger is configured to increase the temperature of the gas stream of treated hydrogen, such that the high gas temperature is above 300°C or above 700°C.

12. The chemical system of claim 1, wherein the heat exchanger is a countercurrent heat exchanger.

13. The chemical system of claim 1, wherein the heat exchanger exchanges heat between at least one of the high-temperature fluid flow of the pyrolysis products and the treated hydrogen at the low gas temperature with at least one heat exchange fluid selected from air, steam, molten metal, molten salt and water.

14. A chemical method for producing treated hydrogen at high gas temperatures, the chemical method comprising: a) A high-temperature fluid stream that pyrolyzes hydrocarbon feedstocks to produce pyrolysis products that mainly contain hydrogen and solid carbon. b) Pass the high-temperature fluid flow of the pyrolysis product through a heat exchanger to deliver a low-temperature fluid flow of the pyrolysis product; c) Processing the cryogenic fluid stream of the pyrolysis products to obtain the processed hydrogen at a low gas temperature, wherein the processing includes at least one of the steps of separating the solid carbon products and compression. and d) The treated hydrogen at the low gas temperature is returned to the heat exchanger, such that the heat exchanger exchanges heat between the high-temperature fluid flow of the pyrolysis products and the treated hydrogen at the low gas temperature to cool the high-temperature fluid flow and heat the treated hydrogen at the low gas temperature, thereby producing the treated hydrogen at the high gas temperature.

15. The chemical method of claim 14, wherein the hydrocarbon feedstock substantially comprises methane or natural gas, and the solid carbon product comprises solid carbon.

16. The chemical method of claim 14, wherein the pyrolysis step is carried out at a temperature between 500°C and 2,000°C.

17. The chemical method of claim 14, wherein a portion of the solid carbon product is fluidized out of the pyrolysis reactor via the high-temperature fluid flow of the pyrolysis product.

18. The chemical method of claim 14, wherein the separation step separates more than 60% of the solid carbon product from the cryogenic fluid stream of the pyrolysis product to produce the treated hydrogen containing more than 70% hydrogen.

19. The chemical method of claim 18, wherein the separation step uses a solid filter selected from the group consisting of cyclone separators, bag filters, and HEPA filters.

20. The chemical method of claim 18, wherein the separation step uses a gas filter selected from the group consisting of pressure swing or temperature swing adsorption systems, distillation systems, and membrane separators.

21. The chemical method of claim 14, wherein the compression step uses a compressor to increase the pressure of the cryogenic fluid flow to between 1 and 1,000 bar absolute pressure.

22. The chemical method of claim 14, wherein the step of passing through the heat exchanger is configured to reduce the temperature of the high-temperature fluid stream of the pyrolysis product to below 500°C or below 300°C.

23. The chemical method of claim 14, wherein the step of passing through the heat exchanger further comprises passing the hydrocarbon feedstock through the heat exchanger to exchange heat between the high-temperature fluid flow of the pyrolysis product and the hydrocarbon feedstock.

24. The chemical method of claim 14, wherein the step of passing through the heat exchanger is configured to increase the temperature of the gas stream of treated hydrogen, such that the high gas temperature is above 300°C or above 700°C.

25. The chemical method of claim 14, wherein in the passing step, the heat exchanger exchanges heat between at least one of the high-temperature fluid flow of the pyrolysis product and the treated hydrogen at the low gas temperature with at least one heat exchange fluid selected from air, steam, molten metal, molten salt and water.

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