Parallel reforming in chemical plants

Abstract

The present invention relates to a chemical plant, comprising: - a reforming section, which is arranged to receive a feed gas containing hydrocarbons and provide a combined synthesis gas stream, wherein the reforming section comprises: - an electrically heated reforming reactor containing a first catalyst, - an autothermal reforming reactor connected in parallel with the electrically heated reforming reactor, wherein the reforming section is arranged to output a combined synthesis gas stream containing at least part of the first and / or second synthesis gas streams; - an optional post-processing unit downstream of the reforming section; - a gas separation unit, which is arranged to separate the synthesis gas stream into water condensate and an intermediate synthesis gas, and a downstream section, which is arranged to receive the intermediate synthesis gas and process the intermediate synthesis gas into chemical products and waste gas. The present invention also relates to a method for producing chemical products from a feed gas containing hydrocarbons.

Description

Technical Field

[0001] The present invention relates to a chemical plant and a method for producing chemical products by heterogeneous catalysis of a feed gas containing hydrocarbons. The present invention particularly relates to a plant and a method for producing synthesis gas, a plant and a method for producing methanol, a plant and a method for producing ammonia, and a plant and a method for producing a mixture of higher hydrocarbons. Background of the Invention

[0003] The process based on autothermal reforming (ATR) is a way to produce synthesis gas. The main elements of the ATR reactor are the burner, combustion chamber and catalyst bed contained in the pressure shell of refractory lining. In the ATR reactor, substoichiometric amount of oxygen partially burns the hydrocarbon feed, and then the partially burned hydrocarbon feed stream is steam reformed in the fixed bed of steam reforming catalyst. Due to the high temperature, a certain degree of steam reforming also occurs in the combustion chamber. The steam reforming reaction is accompanied by the water-gas shift reaction. Generally, relative to steam reforming and water-gas shift reaction, the gas is equal to or close to equilibrium at the outlet of the reactor. The temperature of the outlet gas is generally between 850°C and 1100°C. More details and complete descriptions of ATR can be found in the prior art, such as "Studies in Surface Science and Catalysis", Vol. 152, "Synthesis gas production for FT synthesis"; Chapter 4, p.258-352, 2004.

[0004] It is an object of the present invention to provide an alternative configuration of a chemical plant for producing chemical products.

[0005] Another object of the present invention is to provide a system and method for producing synthesis gas by reforming, wherein the overall energy consumption is reduced compared to a system having a single fired reforming reactor, such as a tubular steam methane reformer, an autothermal reformer, or a convection reformer.

[0006] Another object of the present invention is to provide an apparatus and a method wherein the capacity of an existing reforming reactor, such as a fired reforming reactor or an autothermal reformer, can be increased.

[0007] Another object of the present invention is to provide an apparatus and a method which allow a high degree of flexibility in the composition of the synthesis gas produced.

[0008] Yet another object of the present invention is to provide a chemical plant and process in which carbon dioxide and other climate-damaging emissions (such as NO) are reduced by minimizing the consumption of hydrocarbons to provide heat for the reforming reaction. x 、SO x The total emissions of Summary of the invention

[0009] In the following, reference is made to embodiments of the present invention. However, it should be understood that the present invention is not limited to the specifically described embodiments. In contrast, any combination of the following features and elements, whether or not related to different embodiments, may be considered to implement and practice the present invention.

[0010] One aspect of the present invention relates to a chemical plant, comprising:

[0011] a reforming section arranged to receive a feed gas comprising hydrocarbons and to provide a combined synthesis gas stream, wherein the reforming section comprises:

[0012] - an electrically heated reforming reactor containing a first catalyst, said electrically heated reforming reactor being arranged to receive a first portion of said feed gas and to produce a first synthesis gas stream,

[0013] an autothermal reforming reactor connected in parallel with the electrically heated reforming reactor, the autothermal reforming reactor containing a second catalyst, the autothermal reforming reactor being arranged to receive a second portion of the feed gas and output a second synthesis gas stream,

[0014] wherein the reforming section is arranged to output a combined synthesis gas stream comprising at least a portion of the first and / or second synthesis gas stream,

[0015] - an optional post-treatment unit downstream of the reforming section, wherein the optional post-treatment unit is arranged to receive the combined synthesis gas stream and to provide a post-treated synthesis gas stream,

[0016] a water separation unit arranged to separate the combined synthesis gas stream or the post-treated synthesis gas stream into water condensate and an intermediate synthesis gas, and

[0017] - A downstream section arranged to receive the intermediate synthesis gas and to process the intermediate synthesis gas into chemical products and waste gases.

[0018] In some embodiments, all of the first and / or second synthesis gas is output from the reforming section as a combined synthesis gas stream; however, in other embodiments, only a portion of the first synthesis gas and / or all of certain portions of the second synthesis gas (e.g., 20 volume % of the first and / or second synthesis gas streams) are output as a combined synthesis gas stream, while other portions thereof are output as synthesis gas for other purposes.

[0019] Where it is desired to increase the overall production of synthesis gas within the reforming section of a chemical plant, it may be advantageous to supplement the autothermal reforming reactor with an electrically heated reforming reactor, for example, instead of a steam methane reformer (SMR) or a gas heated reforming reactor (including a heat exchange reformer), if the only reforming reactor is an autothermal reforming reactor.

[0020] This is due at least to:

[0021] - This combination provides lower cumulative CO2 generation compared to a combination of an autothermal reforming reactor and an SMR, especially if the electricity for electrically heating the reforming reactor comes from renewable energy,

[0022] - By minimizing the amount of hydrocarbons used to provide heat for the reforming reaction, carbon dioxide and other climate-damaging emissions (such as NO x or SO x )’s total emissions are significantly reduced;

[0023] - electrically heating the reforming reactor makes it possible to output the first synthesis gas at a higher temperature and / or a higher pressure than is possible with the SMR, thereby ensuring the methane content of the first synthesis gas and, therefore, making it possible to reduce the methane content of the combined synthesis gas;

[0024] - the pressure of the combined syngas can be higher, particularly since SMRs are limited to a maximum pressure of about 25 barg, compared to autothermal and electrically heated reformers, which can both operate at pressures in excess of 30 barg, more preferably in excess of 40 barg;

[0025] - The operating conditions of gas-heated reforming reactors are limited to high steam-to-carbon ratios to avoid metal dusting, which is not the case for electrically heated reforming reactors;

[0026] - The size of the electrically heated reforming reactor is significantly smaller than that of SMR or gas-heated reforming reactors, and therefore it is easier to implement into existing layouts;

[0027] - the oxygen consumption can be indirectly controlled by adjusting the H2 / CO ratio of the combined synthesis gas output from the reforming section by controlling the amount of the first part of the feed gas entering the electrically heated reforming reactor and the amount of the second part of the feed gas entering the autothermal reforming reactor;

[0028] - In addition, the modulus M of the post-processed synthesis gas stream can be adjusted. The modulus M is the stoichiometric ratio (H2-CO2) / (CO+CO2). The modulus M can be adjusted to about 1.8-2.2, more preferably about 2.0 or 2.1, which can be used in the case where the downstream stage includes a methanol reactor arranged to convert the intermediate synthesis gas into methanol.

[0029] In more detail, the technical advantages of the apparatus of the present invention can be explained as follows: ATRs typically produce output gas at a temperature of 1000°C or more and a pressure of up to 45 barg. Conventional SMRs and gas-heated reformers produce output gas at a temperature of about 850°C and a pressure of 25-30 barg. Due to mechanical limitations, SMRs are generally excluded from operation at higher pressures, and gas-heated reformers are excluded from operation at higher pressures because the conversion of methane is disadvantageously reduced at the relevant maximum temperature. In general, this means that the methane conversion in SMRs and gas-heated reformers will be relatively low because the outlet temperature is relatively low, and when mixed with the output gas of the SMR or gas-heated reformer, the result is an increase in the methane content in the gas and a corresponding increase in the methane content in the combined synthesis gas. In addition, the pressure limitation of the SMR or gas-heated reformer means that when the output gas of the ATR is mixed with the output gas of the conventional SMR or gas-heated reformer, the pressure of the gas output from the ATR must be reduced to the same level as the pressure of the output gas from the conventional SMR or gas-heated reformer. The reduction in pressure of the combined synthesis gas means that the requirements for downstream compression of the combined synthesis gas will increase, as many applications of the synthesis gas, such as methanol synthesis (typically above 70 barg) require high pressures. The present invention is based on the recognition that it is possible to produce an output gas from an electrically heated steam methane reformer having the same high temperature and pressure as the output gas from the ATR, thus avoiding said pressure reduction of the output gas from the ATR, thereby producing a combined synthesis gas with a reduced methane content. Thus, it has surprisingly been found that in an electrically heated steam methane reformer, an output gas having a temperature of up to about 1100 or more and a pressure of up to 100 barg can be produced.

[0030] In addition to the second portion of feed gas entering the autothermal reforming reactor, an oxidant gas stream is also introduced. The oxidant gas stream contains oxygen and may be, for example, air or oxygen, or a mixture of more than 90% oxygen with the remainder being, for example, nitrogen, steam and / or argon.

[0031] It should be noted that the first, second and optional third part of the feed gas containing hydrocarbons can be the first, second and optional third part of a single feed gas stream containing hydrocarbons, wherein the single feed gas stream is divided into a plurality of streams that may be fed to the first, second and optional third reforming reactors together with steam. In this case, the composition of the first, second and optional third part of the feed gas is substantially the same. However, before they are fed into respective reforming reactors, additional gas (such as oxidant gas and / or steam) can be added to the first, second and optional third part of the feed gas. Although the first, second and optional third feed gas can be input into the reforming reactor of the reforming section separately, the term "feed gas" received by the reforming section is intended to represent the total amount of feed gas fed to the reforming reactor. Therefore, when the reforming section includes an electrically heated reforming reactor receiving the first part of the feed gas and an autothermal reforming reactor receiving the second part of the feed gas, the term "feed gas" is intended to represent the total feed gas of the first and second parts comprising the feed gas. Similarly, when the reforming section includes an electrically heated reforming reactor receiving a first portion of the feed gas, an autothermal reforming reactor receiving a second portion of the feed gas, and a gas heated reforming reactor receiving a third portion of the feed gas, the term "feed gas" refers to the total feed gas comprising the first, second and third portions of the feed gas.

[0032] The chemical plant of the present invention increases the output of the combined synthesis gas of the reforming section. An alternative method to increase the output of the reforming section is to combine a combustion steam methane reformer and an autothermal reforming reactor or to combine an autothermal reforming reactor with a heat exchange reforming reactor. The combination of an electric heating reforming reactor and an autothermal reforming reactor is superior to the combination of a combustion steam methane reforming reactor and an autothermal reforming reactor because the total CO2 emissions are reduced and because the temperature and / or pressure of the combined synthesis gas is higher than the previous combination. In addition, the combination of an electric heating reforming reactor and an autothermal reforming reactor is superior to the combination of an autothermal reforming reactor and a heat exchange reforming reactor because the heat exchange reforming reactor is limited to operating at a high steam-to-carbon ratio to avoid metal dusting problems.

[0033] The chemical plant of the present invention provides the concept of obtaining synergy between the operation of the electrically heated reforming reactor and the autothermal reforming reactor. By arranging the electrically heated reforming reactor in parallel with the autothermal reforming reactor, the two reforming reactors can use the same preheating and pretreatment system or part thereof together. In addition, compared with using a steam methane reforming reactor in parallel with the autothermal reforming reactor, the input of hydrocarbons that provide heat for the steam reforming reaction is reduced by allowing part of the reforming reaction to be carried out in the electrically heated reforming reactor. Therefore, for a given output of the combined synthesis gas from the reforming section, the total consumption of hydrocarbons is minimized.

[0034] Furthermore, by combining an autothermal reforming reactor with an electrically heated reforming reactor, the composition of the synthesis gas leaving the reforming section can be controlled. This is particularly useful if the downstream section is, for example, a methanol synthesis section.

[0035] The capacity of an existing chemical plant with an autothermal reforming reactor can be increased by adding an electrically heated reforming reactor with little, if any, increase in hydrocarbon usage for the heating side of the reforming stage, since the electricity for the electrically heated reforming reactor can be provided from renewable sources such as wind power. Furthermore, since the electrically heated reforming reactor is a very compact reactor, it can often be installed on the same land as an existing chemical plant.

[0036] The downstream section may for example be a cold box, a pressure swing adsorption unit, a methanol synthesis section, an ammonia section or a Fischer-Tropsch section. Other downstream sections are also possible, such as a downstream section for acetic acid production or DME production.

[0037] In a fired tube steam methane reformer, heat transfer by convection and / or radiant heating can be slow and often encounters significant resistance. Due to the rate of heat transfer through the tube walls and to the catalyst inside the tube and due to the endothermic nature of the steam reforming reaction, the innermost temperature of the tubes of a fired tube steam methane reformer is slightly lower than the outside temperature of the tubes. In an electrically heated reforming reactor, the highest temperatures can be obtained near the first catalyst. Therefore, by utilizing electrical heating, the high temperature flue gases of a fired steam methane reformer are avoided, and therefore less energy is required in the reforming section of the electrically heated reactor. In addition, by minimizing the amount of hydrocarbons used to provide heat for the reforming reaction, carbon dioxide and other emissions harmful to the climate (such as NO) are reduced. x or SO x )’s total emissions.

[0038] Furthermore, if the electricity used for heating the electrically heated reforming reactor and possible other units of the chemical plant is provided by renewable energy sources, the overall consumption of hydrocarbons for the chemical plant will be minimized and CO2 emissions will be reduced accordingly.

[0039] Typically, the combined synthesis gas stream from the reforming section comprises the first and second synthesis gas streams. Therefore, the further processing of the combined synthesis gas stream from the reforming section is used in combination in all the first and second synthesis gas streams. However, it is conceivable that the combined synthesis gas stream comprises only a portion of the first and / or second synthesis gas streams, and the remaining synthesis gas stream is directed to other equipment downstream of the reforming section. This can be, for example, the following situation, where the chemical plant is arranged to provide a chemical product in the form of a hydrogen stream and another chemical product in the form of a synthesis gas stream rich in CO.

[0040] In the context of the present application, the term "feed gas containing hydrocarbons" is intended to mean a gas having one or more hydrocarbons and possible other components. Therefore, generally, in addition to a small amount of other gases, the feed gas containing hydrocarbons contains hydrocarbon gas, such as CH4 and optionally a relatively small amount of higher hydrocarbons. Higher hydrocarbons are components with two or more carbon atoms, such as ethane and propane. Examples of "hydrocarbon gas" can be natural gas, LPG, city gas, biogas, naphtha or a mixture of methane and higher hydrocarbons. Hydrocarbons can also be components with other atoms other than carbon and hydrogen, such as oxygenates. The term "feed gas containing hydrocarbons" refers to a feed gas containing hydrocarbon gas, wherein one or more hydrocarbons are mixed with steam, hydrogen and possible other components (such as carbon monoxide, carbon dioxide and nitrogen and argon). Generally, the feed gas entering the reforming section has a predetermined ratio of hydrocarbon gas, steam and hydrogen, and may also have carbon dioxide. It should be noted that a feed gas comprising purified (e.g., desulfurized and / or pre-reformed) hydrocarbons is still considered to be a feed gas containing hydrocarbons.

[0041] Furthermore, the term "steam reforming" or "steam methane reforming reaction" refers to a reforming reaction that proceeds according to one or more of the following reactions:

[0042]

[0043] Reactions (i) and (ii) are steam methane reforming reactions, while reaction (iii) is a dry methane reforming reaction.

[0044] For higher hydrocarbons, i.e., C n H m , where n≥2, m≥4, formula (i) can be summarized as:

[0045] Where n≥2, m≥4

[0046] Typically, steam reforming is accompanied by a water-gas shift reaction (v):

[0047]

[0048] The terms "steam methane reforming" and "steam methane reforming reaction" are meant to cover reactions (i) and (ii), the term "steam reforming" is meant to cover reactions (i), (ii) and (iv), and the term "methanation" covers the reverse reaction of reaction (i). In most cases, all of these reactions (i)-(v) are at or near equilibrium at the outlet of the reforming reactor. The term "pre-reforming" is generally used to cover the catalytic conversion of higher hydrocarbons according to reaction (iv). Pre-reforming is generally accompanied by steam reforming and / or methanation (depending on the gas composition and operating conditions) and the water gas shift reaction. Pre-reforming is generally carried out in an adiabatic reactor, but can also be carried out in a heated reactor.

[0049] In the case of autothermal reforming, the steam methane reforming is preceded by a reaction zone in which combustion and partial combustion of the feedstock occurs.

[0050] Furthermore, in addition to steam methane reforming reactions, the terms "autothermal reforming" and "autothermal reforming reaction" also encompass the combustion and partial combustion of a hydrocarbon feedstock according to reactions (vi) and (vii):

[0051]

[0052] The term "synthesis gas" refers to a gas comprising hydrogen, carbon monoxide and also carbon dioxide and small amounts of other gases such as argon, nitrogen, methane and the like.

[0053] Typically, before entering the reforming stage, the feed gas will undergo desulfurization to remove sulfur from it, thereby avoiding deactivation of the catalyst in the process.

[0054] In one embodiment, the chemical plant further comprises a gas purification unit and / or a pre-reforming unit upstream of the reforming section. The gas purification unit is, for example, a desulfurization unit, such as a hydrodesulfurization unit.

[0055] In the pre-reformer, the hydrocarbon gas will be pre-reformed according to reaction (iv) with steam, and possibly hydrogen and / or other components such as carbon dioxide, in a temperature range of about 350-550° C. to convert higher hydrocarbons as the initial step of the process, which usually occurs downstream of the desulfurization step. This eliminates the risk of carbon formation from higher hydrocarbons on the catalyst in subsequent process steps. Optionally, carbon dioxide or other components can also be mixed with the gas leaving the pre-reforming step to form the feed gas.

[0056] In one embodiment, the water separation unit of the chemical plant is a flash separation unit, usually preceded by a suitable cooling device. Flash separation refers to a phase separation unit in which, at a given temperature, a stream is separated into a liquid phase and a gas phase that are close to or in thermodynamic phase equilibrium.

[0057] In one embodiment, an electrically heated reforming reactor of a chemical plant comprises:

[0058] a pressure shell housing an electric heating unit arranged to heat said first catalyst, wherein the first catalyst comprises a catalytically active material operable to catalyze steam reforming of a first feed gas, wherein the pressure shell has a design pressure between 5 and 45 bar, preferably between 30 and 45 bar,

[0059] - a thermal insulation layer adjacent to at least a portion of the interior of the pressure vessel, and

[0060] - at least two conductors electrically connected to the electric heating unit and electrically connected to a power source placed outside the pressure vessel,

[0061] Wherein the power supply is sized to heat at least a portion of the first catalyst to a temperature of at least 800°C, preferably at least 950°C, or even more preferably at least 1050°C by passing an electric current through the electric heating unit.

[0062] An important feature of an electrically heated reforming reactor is that energy is provided inside the reforming reactor, rather than by external heat sources such as heat conduction, convection and radiation, such as through catalyst tubes. In an electrically heated reforming reactor having an electric heating unit connected to a power source by a conductor, the heat for the steam reforming reaction is provided by resistive heating. The hottest part of the electrically heated reforming reactor will be located within the pressure shell of the electrically heated reforming reactor. Preferably, the power source and the electric heating unit within the pressure shell are sized so that at least a portion of the electric heating unit reaches a temperature of 850°C, preferably 900°C, more preferably 1000°C or even more preferably 1100°C.

[0063] The chemical plant of the present invention may advantageously include one or more compressors and / or pumps upstream of the reforming section. The compressor / pump is arranged to compress the feed to a pressure between 5 and 45 bar, preferably between 30 and 45 bar. The components of the feed, i.e. water / steam, hydrogen and hydrocarbon feed gas, may be compressed separately and fed separately to the reforming section or its reforming reactor.

[0064] The first catalyst can be a bed of catalyst particles (e.g., pellets), which are typically in the form of a catalytically active material supported on a high-area support, wherein the conductive structure is embedded in the bed of catalyst particles. Alternatively, the first catalyst can be a catalytically active material supported on a macrostructure (e.g., a monolith).

[0065] When the electrically heated reforming reactor includes an insulating layer adjacent to at least a portion of the interior of the pressure shell, appropriate thermal and electrical insulation is obtained between the electrically heated unit and the pressure shell. Typically, the insulating layer will be present over a large portion of the interior of the pressure shell to provide thermal insulation between the pressure shell and the electrically heated unit / first catalyst; however, channels in the insulating layer are required to provide connection of conductors between the electrically heated unit and the power source and to provide inlet / outlet for gas to enter / exit the electrically heated reforming reactor.

[0066] The presence of an insulation layer between the pressure shell and the electric heating unit helps to avoid overheating of the pressure shell and helps to reduce heat losses around the electric heated reforming reactor. The temperature of the electric heating unit, at least in certain parts thereof, can reach about 1300°C, but by using an insulation layer between the electric heating unit and the pressure shell, the temperature of the pressure shell can be maintained at a significantly lower temperature, such as 500°C or even 200°C. This is advantageous because conventional construction steels are not suitable for applications that are subjected to pressure at high temperatures (e.g., above 1000°C). In addition, the insulation layer between the pressure shell and the electric heating unit helps to control the current within the reforming reactor because the insulation layer is also electrically insulating. The insulation layer can be one or more layers of solid material, such as ceramic, inert material, refractory material or gas barrier layer or a combination thereof. Therefore, it is also conceivable that the purge gas or confined gas constitutes or forms part of the insulation layer.

[0067] Since the hottest part of the electrically heated reforming reactor during operation is the electric heating unit, and since the insulation layer insulates the pressure shell from the electrically heated reforming reactor, the temperature of the pressure shell can be kept significantly lower than the maximum process temperature. This allows the pressure shell to have a relatively low design temperature, for example, the pressure shell is 700°C or 500°C or preferably 300°C or 200°C, while having a maximum process temperature of 900°C or even 1100°C or even up to 1300°C.

[0068] Another advantage is that the lower design temperature compared to combustion SMRs means that in some cases the thickness of the pressure vessel can be reduced, saving costs.

[0069] It should be noted that the term "insulating material" is intended to mean a material having a thermal conductivity of about 10 W·m -1 ·K -1 Examples of thermal insulation materials are ceramics, refractory materials, alumina-based materials, zirconia-based materials, and the like.

[0070] In one embodiment, the electric heating unit comprises a macrostructure of conductive material, wherein the macrostructure carries a ceramic coating and the ceramic coating carries a catalytically active material of a first catalyst. Therefore, during operation of the chemical plant, an electric current passes through the macrostructure and thereby heats the macrostructure and the catalytically active material carried thereon. The close proximity between the catalytically active material and the macrostructure enables the catalytically active material to be effectively heated by heat conduction from the solid material of the macrostructure heated by electrical resistance. Under given operating conditions, the amount and composition of the catalytically active material can be adjusted according to the steam reforming reaction. Under given operating conditions, the surface area of ​​the macrostructure, the proportion of the macrostructure coated with the ceramic coating, the type and structure of the ceramic coating, and the amount and composition of the catalytically active material can be adjusted according to the steam reforming reaction.

[0071] The term "conductive" means a resistivity of 10 at 20°C. -4 Up to 10 -8 Ω·m. Thus, the conductive material is, for example, a metal such as copper, silver, aluminum, chromium, iron, nickel, or a metal alloy. Furthermore, the term "electrically insulating" means a material having a resistivity higher than 10 Ω·m at 20°C, for example 10 9 Up to 10 25 Ω·m material.

[0072] As used herein, the term "electric heating unit containing a macro-catalyst" is not meant to be limited to a reforming reactor having a single macrostructure. Rather, the term is intended to encompass a macrostructure having a ceramic coating and a catalytically active material supported thereon, as well as a series of such macrostructures having a ceramic coating and a catalytic material supported thereon.

[0073] The term "macrostructure loaded with a ceramic coating" is intended to mean that the macrostructure is coated with a ceramic coating at at least a portion of the surface of the macrostructure. Thus, the term does not mean that all surfaces of the macrostructure are covered with the ceramic coating; in particular, there is no coating at least on the portion of the macrostructure that is electrically connected to the conductor and thus to the power source. The coating is a ceramic material having pores in its structure, on which the catalytically active material of the first catalyst can be loaded and within the coating, and has the same function as a catalytic support. Advantageously, the catalytically active material of the first catalyst comprises catalytically active particles having a size ranging from about 5 nm to about 250 nm.

[0074] As used herein, the term "macrostructure" is intended to mean a structure that is large enough to be visible to the naked eye without the need for a magnifying device. The dimensions of the macrostructure are typically in the range of centimeters or even meters. It is advantageous to have the dimensions of the macrostructure correspond at least partially to the internal dimensions of the pressure vessel, thereby saving space for insulation and conductors.

[0075] Ceramic coatings with or without catalytically active materials can be added directly to metal surfaces by washcoating. Washcoating of metal surfaces is a well-known process; described, for example, in Cybulski, A., and Moulijn, JA, Structured catalysts and reactors, Marcel Dekker, Inc, New York, 1998, Chapter 3, and references therein. The ceramic coating can be added to the surface of the macrostructure and subsequently the catalytically active material can be added; alternatively, the ceramic coating containing the catalytically active material is added to the macrostructure.

[0076] Preferably, the macrostructure is manufactured by extruding a mixture of powdered metal particles and a binder into an extruded structure and then sintering the extruded structure, thereby providing a material with a high geometric surface area per unit volume. In order to form a chemical bond between the ceramic coating and the macrostructure, a ceramic coating that may contain a catalytic material is provided on the macrostructure before the second sintering in an oxidizing atmosphere. Alternatively, the catalytically active material may be impregnated onto the ceramic coating after the second sintering. When a chemical bond is formed between the ceramic coating and the macrostructure, a particularly high thermal conductivity between the electrically heated macrostructure and the catalytically active material supported by the ceramic coating is possible. Since the distance between the heat source, i.e., the macrostructure and the catalytically active material is very close, heat transfer is effective, thereby the catalytically active material can be heated very effectively. Therefore, in terms of gas processing per unit reforming reactor volume, a compact reforming reactor is possible, and therefore a reforming reactor that accommodates the macrostructure can be compact. The reforming reactor of the present invention does not require a furnace and this significantly reduces the size of the electrically heated reforming reactor.

[0077] In another embodiment, the macroscopic mixture is manufactured by 3D printing and / or additive manufacturing.

[0078] Preferably, the macrostructure comprises Fe, Ni, Cu, Co, Cr, Al, Si or an alloy thereof. Such alloys may contain other elements, such as Mn, Y, Zr, C, Co, Mo or a combination thereof. Preferably, the catalytically active material of the first catalyst is a particle having a size of 5 nm to 250 nm. The catalytically active material of the first catalyst may, for example, comprise nickel, ruthenium, rhodium, iridium, platinum, cobalt or a combination thereof. Thus, a possible catalytically active material of the first catalyst is a combination of nickel and rhodium and another combination of nickel and iridium. The ceramic coating may, for example, be an oxide comprising Al, Zr, Mg, Ce and / or Ca. Exemplary coatings are calcium aluminate or magnesium aluminum spinel. Such a ceramic coating may contain additional elements, such as La, Y, Ti, K or a combination thereof. Preferably, the conductor is made of a material different from the macrostructure. The conductor may be, for example, iron, nickel, aluminum, copper, silver or an alloy thereof. The ceramic coating is an electrically insulating material having a thickness typically around 100 μm, such as 10-500 μm. Additionally, a sixth catalyst may be placed within the pressure shell and in channels within the macrostructure, around or upstream of the macrostructure and / or upstream of the macrostructure to support the catalytic function of the macrostructure.

[0079] In one embodiment, the chemical plant further comprises a control system arranged to control the power supply to ensure that the temperature of the gas leaving the electrically heated reforming reactor is within a predetermined range and / or that the conversion of hydrocarbons in the first portion of the feed gas is within a predetermined range and / or that the dry molar concentration of methane is within a predetermined range and / or that the approach to equilibrium of the steam reforming reaction is within a predetermined range. Typically, the maximum temperature of the gas within the electrically heated reforming reactor is between 800°C and 1000°C, such as between 850°C and 1000°C, such as at about 950°C, but even higher temperatures are conceivable, such as up to 1300°C. The maximum temperature of the first synthesis gas will be achieved at the most downstream portion close to the first catalyst as seen in the flow direction of the first portion of the feed gas.

[0080] The control of the power supply is the control of the electrical output of the power supply. The control of the power supply can be performed, for example, as the control of the voltage and / or current from the power supply, as the control of whether the power supply is on or off, or a combination thereof. The power provided to the electric heating unit of the first catalyst can be in the form of alternating current or direct current.

[0081] In one embodiment, the chemical plant also includes a combustion heater unit upstream of the autothermal reforming reactor (ATR reactor) and optionally a device for recycling at least part of the exhaust gas from the downstream section as fuel to the combustion heater unit, wherein the combustion heater unit is arranged to preheat the second part of the feed gas.

[0082] By recycling the exhaust gas from the downstream section back to the combustion heater unit, it is possible to maximize the utilization of hydrocarbons in the feed on the process side and minimize the use of hydrocarbons in the combustion heating unit. The chemical plant can be balanced so that the operation of the combustion heating unit is adjusted to be driven mainly or even completely by the heat supplied by the combustion of the recycled exhaust gas. This allows the use of the input natural gas for combustion heating in the chemical plant to be minimized, which in turn allows the optimization of the utilization of the feed gas containing hydrocarbons input to the chemical plant. Typically, a relatively small amount of supplementary gas containing hydrocarbons is also fed to the combustion heating unit to allow the load of the combustion heating unit to be controlled. The term "load" is understood in this article as the heat input added or removed in the unit operation of the chemical plant.

[0083] In one embodiment, the reforming section also includes a combustion steam methane reforming reactor upstream of the autothermal reforming reactor, wherein the combustion steam methane reforming reactor comprises one or more tubes containing a third catalyst, wherein the combustion steam methane reforming reactor comprises one or more burners for providing heat for the steam methane reforming reaction within the one or more tubes, and wherein the chemical plant includes a device for recycling at least part of the exhaust gas from the downstream section as fuel to the one or more burners of the combustion steam methane reforming reactor, wherein the combustion steam methane reforming reactor is arranged to receive a second portion of the feed gas and provide a partially reformed second feed gas, and wherein the partially reformed second feed gas is directed to the autothermal reforming reactor.

[0084] A typical combustion steam methane reforming reactor has a number of tubes placed inside a furnace, which are filled with catalyst pellets. The tubes are usually 10-13 meters long and the inner diameter is usually between 80 and 160 mm. Burners placed in the furnace provide the required heat for the reaction by burning fuel gas.

[0085] The fuel gas used for these combustion processes is typically a mixture of exhaust gas from a process downstream of the reformer and input natural gas or other suitable hydrocarbon.

[0086] Since the temperature of the partially reformed second feed gas leaving the fired steam methane reforming reactor may be relatively high, for example 700°C to 900°C, the second portion of the feed gas does not need to be preheated in a separate fired heater unit before being introduced into the autothermal reforming reactor.

[0087] In one embodiment, the reforming section of the chemical plant also includes a gas-heated steam methane reforming reactor in parallel with the combination of the electrically heated reforming reactor and the autothermal reforming reactor. The gas-heated steam methane reforming reactor contains a fourth catalyst and is operable to receive a third portion of the feed gas and utilize at least a portion of the first and / or second synthesis gas streams as a heating medium for heat exchange within the gas-heated steam methane reforming reactor. The gas-heated steam methane reforming reactor is arranged to produce a third synthesis gas stream on the fourth catalyst and is used to output the third synthesis gas stream from the reforming section as at least a portion of the combined synthesis gas. Since the sensitive heat of the first and second synthesis gas streams is used in the gas-heated steam methane reforming reactor, the total thermal efficiency of the chemical plant is improved by adding a gas-heated steam methane reforming reactor. In addition, when the chemical plant includes a gas-heated steam methane reforming reactor, the total output of the chemical plant increases.

[0088] Gas heated steam methane reforming reactors are configured to use hot gas to provide heat for the endothermic steam methane reforming reaction by heat exchange, typically on the tube walls. One example of a configuration of a heat exchange reformer has a plurality of parallel tubes filled with catalyst that receive a feed gas. At the bottom of the reactor, product gas from the catalyst filled tubes is mixed with hot syngas from an upstream reforming unit, and the combined syngas is heat exchanged with the catalyst filled tubes. Other configurations of heat exchange reformers are also contemplated.

[0089] Reducing Metal Dust in Heat Exchange Reforming Reactors

[0090] In one embodiment, the reforming section further comprises a gas heated steam methane reforming reactor upstream of the autothermal reforming reactor, wherein the gas heated steam methane reforming reactor comprises a fourth catalyst and is operable to utilize at least a portion of the second synthesis gas stream as a heating medium for heat exchange within the gas heated steam methane reforming reactor, the gas heated steam methane reforming reactor being arranged to receive the second portion of the feed gas and provide a partially reformed second feed gas, wherein the partially reformed second feed gas is introduced into the autothermal reforming reactor. In a specific embodiment, the gas heated steam methane reforming reactor is also operable to utilize at least a portion of the first synthesis gas stream as a heating medium for heat exchange within the gas heated steam methane reforming reactor.

[0091] By adding a gas heated steam methane reforming reactor, the overall thermal efficiency of the chemical plant is increased, since the sensitive heat of the first and second synthesis gas streams is used in the gas heated steam methane reforming reactor. Furthermore, the overall output of the chemical plant is increased when the chemical plant comprises a gas heated steam methane reforming reactor. Gas heated steam methane reforming reactors in the form of heat exchange reformers have an inherent technical problem of metal dusting, i.e. corrosion of the metal surfaces of the reactor when exposed to a carbon monoxide rich gas. Metal dusting can be described by the following reaction:

[0092]

[0093] Surprisingly, it was found that when an electrically heated reforming reactor in parallel with the combination of a heat exchange reformer and an autothermal reforming reactor was added, the level of metal dusting in the heat exchange was greatly reduced. Without being bound by theory, it is believed that this is due to the reduction in the temperature difference between the equilibrium temperature of reaction (viii) and the outlet temperature of the second synthesis gas after cooling in the heat exchange reformer. The temperature of the second synthesis gas leaving the heat exchange reformer is higher than the temperature when the electrical reformer is not included.

[0094] Further advantages of the above embodiment include:

[0095] - The required duty on the heat exchange reformer is reduced, ie the size of the reformer is reduced.

[0096] - The electrically heated reforming reactor is a very compact reactor compared to combustion reactors and steam reformers, thus reducing the reactor footprint.

[0097] - Electrically heated reforming reactors offer the possibility to operate the reactor using only sustainable energy sources, thus minimizing CO2 emissions.

[0098] In a specific embodiment, the first portion of the feed gas is less than 25 volume %, preferably less than 20 volume %, more preferably less than 15 volume % of the total feed gas.

[0099] In a specific embodiment, the duty transferred in the electrically heated reforming reactor is less than 40%, preferably less than 30%, more preferably less than 20% of the total duty transferred in the electrically heated reforming reactor and the gas heated steam methane reforming reactor.

[0100] In a specific embodiment, the temperature of the second synthesis gas leaving the gas heated steam methane reforming reactor is above 600°C, preferably above 650°C, more preferably above 700°C.

[0101] In a specific embodiment, the difference between the equilibrium temperature of reaction (viii) and the outlet temperature of the second synthesis gas after cooling in the heat exchange reformer is less than 250°C, preferably less than 150°C, and more preferably less than 75°C.

[0102] The equilibrium temperature of reaction (viii) can be obtained by initially calculating the reaction quotient (Q) for a given gas as follows:

[0103]

[0104] Here j is the mole fraction of compound j and P is the total pressure in bar. This is used to determine the equilibrium temperature (T) at which the quotient of a given reaction equals the equilibrium constant. eq ):

[0105] Q=K COred (T eq )

[0106] where Kcored is the thermodynamic equilibrium constant of reaction (viii). Then the equilibrium temperature (ΔT app，COred ) is defined as:

[0107] ΔT app，COred =T eq -T

[0108] Where T is the bulk temperature of the gas.

[0109] In one embodiment, the feed gas is desulfurized and adiabatically pre-reformed prior to being divided into the first and second portions of the feed gas. In one embodiment of the invention, steam is added to the first portion of the feed gas. In one embodiment of the invention, steam is added to the second portion of the feed gas. In one embodiment of the invention, steam is added to both the first and second portions of the feed gas. In one embodiment of the invention, the first and second portions of the feed gas have the same composition. In a specific embodiment of the invention, the first and second portions of the feed gas have different compositions.

[0110] In a specific embodiment, the method of the present invention relates to a method wherein the reforming section further comprises a gas heated steam methane reforming reactor located upstream of the autothermal reforming reactor, wherein the gas heated steam methane reforming reactor comprises a fourth catalyst, the method further comprising the steps of:

[0111] - introducing said second portion of the feed gas into said gas heated steam methane reforming reactor and subjecting it to steam methane reforming in said fired reforming reactor to provide a partially reformed second feed gas,

[0112] - providing the partially reformed second feed gas to the autothermal reforming reactor, and

[0113] - utilizing at least part of said first and / or second synthesis gas stream as heating medium for heat exchange in said gas heated steam methane reforming reactor.

[0114] A specific embodiment of the method of the preceding paragraph further comprises the following steps:

[0115] At least a portion of the first synthesis gas stream is utilized as a heating medium for heat exchange within the gas heated steam methane reforming reactor.

[0116] Further implementation plans

[0117] In one embodiment, the post-processing unit is a post-conversion unit with an inlet that allows heated CO2 to be added to the combined synthesis gas upstream of the post-conversion unit. The post-processing unit accommodates a fifth catalyst for catalyzing steam methane reforming, methanation, and reverse water gas shift reactions. The post-conversion unit is, for example, an adiabatic post-conversion device or a gas heat exchange reactor. The post-processed synthesis gas stream is a synthesis gas stream with a H2 / CO ratio lower than the H2 / CO ratio of the combined synthesis gas. By adding heated CO2 in a separate reactor downstream of the reforming section and performing steam methane reforming, methanation, and reverse water gas shift reactions, the CO production of the process can be increased and / or the H2 / CO ratio can be adjusted. The H2 / CO ratio of the post-processed synthesis gas stream is, for example, lower than 1.8, lower than 1.5, or even lower than 1.0. The temperature of the heated CO2 added can be, for example, a temperature of about 300°C, 400°C, or even about 500°C or higher.

[0118] In one embodiment, the post-treatment unit is a water-gas shift unit arranged to perform a water-gas shift reaction. In this embodiment, the intermediate synthesis gas (i.e., the post-treated synthesis gas) is a water-gas shift synthesis gas stream, such as a hydrogen-rich synthesis gas or a hydrogen stream. The water-gas shift unit can be a single water-gas shift unit, such as a medium-temperature water-gas shift unit, or a combination of two or more water-gas shift units (e.g., a high-temperature water-gas shift unit and a low-temperature water-gas shift unit).

[0119] In one embodiment, the downstream section comprises a gas separation unit arranged to separate a stream of substantially pure CO 2 , H 2 and / or CO from the syngas inlet to the downstream section, thereby providing a refined syngas.

[0120] Here, the term "refined synthesis gas" refers to the synthesis gas obtained from the intermediate synthesis gas after the selective gas separation of CO, CO2 or H2 or the selective gas separation of CO2 and CO or H2. The gas separation unit includes one or more of the following units: CO2 removal unit, pressure swing adsorption unit, membrane and / or cryogenic separation unit. CO2 removal refers to a unit that removes CO2 from the process gas using a process such as chemical adsorption. In chemical adsorption, the CO2-containing gas is passed through a solvent that reacts with CO2 and binds in this way. Most chemical solvents are amines, which are divided into primary amines such as monoethanolamine (MEA) and diglycolamine (DGA), secondary amines such as diethanolamine (DEA) and diisopropanolamine (DIPA), or tertiary amines such as triethanolamine (TEA) and methyldiethanolamine (MDEA), but ammonia and liquid alkali metal carbonates such as K2CO3 and NaCO3 can also be used. Variable adsorption refers to a unit for the adsorption of selected compounds. In this type of equipment, the gas molecules establish a dynamic equilibrium between adsorption and desorption on the adsorption material. The adsorption of gas molecules can be caused by steric, kinetic or equilibrium effects. The exact mechanism will be determined by the adsorbent used, and the equilibrium saturation will depend on temperature and pressure. Typically, the adsorbent material is treated in a mixed gas until the heaviest compound is close to saturation, and then regeneration is required. Regeneration can be accomplished by changing the pressure or temperature. In practice, this means using a process with at least two units, first saturating the adsorbent at high pressure or low temperature in one unit, then switching the unit and now desorbing the adsorbed molecules from the same unit by reducing the pressure or increasing the temperature. When the unit is operated under pressure changes, it is called a pressure swing adsorption unit, and when the unit is operated under temperature changes, it is called a temperature swing adsorption unit. Pressure swing adsorption can produce hydrogen purity of 99.9% or more. Membrane refers to separation on at least partially solid barriers (such as polymers), in which the transmission of individual gas species occurs at different rates determined by their permeabilities. This allows the components in the membrane retentate to be increased or diluted. Low temperature separation refers to the process of separating individual components from a gas mixture by controlling the temperature using the phase change of different substances in the gas, which usually occurs at less than -150°C. It should be noted that the gas separation unit also potentially provides a by-product stream, such as a CO 2 stream from a CO 2 removal operation.

[0121] In one embodiment, the downstream section comprises an ammonia reactor to convert the intermediate synthesis gas into ammonia. In another embodiment, the downstream section comprises a methanol reactor to convert the intermediate synthesis gas into methanol. In yet another embodiment, the downstream section comprises a Fischer-Tropsch reactor to convert the intermediate synthesis gas into a mixture of higher hydrocarbons.

[0122] In one embodiment, the first, second, third, fourth, fifth and / or sixth catalyst is a catalyst suitable for steam reforming reaction, pre-reforming reaction, methanation and / or water gas shift reaction. Examples of relevant such catalysts are Ni / MgAl2O4, Ni / CaAl2O4, Ni / Al2O3, Fe2O3 / Cr2O3 / MgO and Cu / Zn / Al2O3. In one embodiment, the first, second, third, fourth, fifth and / or sixth catalyst is a steam reforming catalyst. Examples of steam reforming catalysts are Ni / MgAl2O4, Ni / Al2O3, Ni / CaAl2O4, Ru / MgAl2O4, Rh / MgAl2O4, Ir / MgAl2O4, Mo2C, Wo2C, CeO2, precious metals on Al2O3 carriers, but other catalysts suitable for reforming are also conceivable.

[0123] Another aspect of the invention relates to a method for producing a chemical product from a feed gas containing hydrocarbons in a chemical plant, the chemical plant comprising a reforming section. The reforming section comprises an electrically heated reforming reactor containing a first catalyst, an autothermal reforming reactor connected in parallel with the electrically heated reforming reactor. The autothermal reforming reactor contains a second catalyst. The method comprises the following steps:

[0124] - introducing a first portion of the feed gas into an electrically heated reforming reactor and subjecting it to steam methane reforming to provide a first synthesis gas stream,

[0125] - introducing a second portion of the feed gas into an autothermal reforming reactor and reforming it to provide a second synthesis gas stream,

[0126] - outputting from the reforming section a combined synthesis gas stream comprising at least part of said first and / or second synthesis gas stream,

[0127] - optionally, post-treating the combined synthesis gas stream in a post-treatment unit downstream of the electrically heated reforming reactor and the autothermal reforming reactor to provide a post-treated synthesis gas stream,

[0128] - separating the combined synthesis gas stream or the post-treated synthesis gas stream into water condensate and an intermediate synthesis gas in a water separation unit downstream of the post-treatment unit, and

[0129] - providing the intermediate syngas to a downstream section arranged to receive the intermediate syngas and to process the intermediate syngas into chemical products and waste gases.

[0130] The advantages of the method and its embodiments correspond to the advantages of the chemical plant and its embodiments, and are therefore not described in further detail here.

[0131] However, it should be noted that the first, second and optional third part of the feed gas comprising hydrocarbons can be the first, second and optional third part of a single feed gas stream comprising hydrocarbons, wherein the single feed gas stream is divided into a plurality of streams that may be fed to the first, second and optional third reforming reactors together with steam. In this case, the composition of the first, second and optional third part of the feed gas is substantially the same. However, before they are fed into respective reforming reactors, additional gas (e.g., oxidant gas and / or steam) can be added to the first, second and optional third part of the feed gas.

[0132] In one embodiment, the first portion of the feed gas is about 5-20% by volume of the feed gas. In the case where the reforming section includes an electrically heated reforming reactor and a combustion reforming reactor and no other reactors, the first portion of the feed gas entering the electrically heated reforming reactor is advantageously about 10-20% by volume of the feed gas, such as about 15% by volume, and thus the second portion of the feed gas entering the autothermal reforming reactor is about 80-90% by volume of the feed gas, such as about 85 vol%.

[0133] In one embodiment, wherein the reforming stage comprises a gas heated steam methane reforming reactor, the first portion of the feed gas is about 5-10% by volume of the feed gas, the second portion of the feed gas is about 80-90% by volume of the feed gas, and the third portion of the feed gas is about 5-10% by volume of the feed gas.

[0134] Furthermore, it should be noted that the order in which the process steps are written is not necessarily the order in which the process steps occur, as two or more steps may occur simultaneously or the order may differ from that described above.

[0135] BRIEF DESCRIPTION OF THE DRAWINGS

[0136] Figure 1 A chemical plant according to an embodiment of the present invention is shown, wherein the reforming section comprises an autothermal reforming reactor and an electrically heated reforming reactor connected in parallel;

[0137] Figure 2 A chemical gas plant according to an embodiment of the invention is shown, wherein the reforming stage further comprises a fired steam methane reforming reactor upstream of the autothermal reforming reactor; and

[0138] Figure 3 A chemical plant according to an embodiment of the invention is shown, wherein the reforming section comprises four reforming reactors.

[0139] Figure 4A chemical gas plant according to an embodiment of the invention is shown, wherein the reforming stage further comprises a gas heated steam methane reforming reactor upstream of the autothermal reforming reactor. DETAILED DESCRIPTION OF THE INVENTION

[0141] Figure 1 A chemical plant 100 according to one embodiment of the present invention is shown. The chemical plant 100 comprises a reforming section 110 having an autothermal reforming reactor 109 and an electrically heated reforming reactor 108 connected in parallel.

[0142] The electrically heated reforming reactor 108 contains a first catalyst and the autothermal reforming reactor 109 contains a second catalyst. The electrically heated reforming reactor 108 is heated by a power source 107.

[0143] The electrically heated reforming reactor 108 and the autothermal reforming reactor 109 are arranged in parallel. The electrically heated reforming reactor 108 is heated by the power supply 107. The electrically heated reforming reactor 108 and the autothermal reforming reactor 109 are arranged to receive the first part 25a and the second part 25b of the feed gas 25 and produce the first synthesis gas 30a and the second synthesis gas 30b respectively.

[0144] During operation of the chemical plant 100, a feed gas 21 containing hydrocarbons undergoes feed purification in the desulfurization unit 101 and becomes a sweetened gas 22. The feed gas 21 containing hydrocarbons is, for example, natural gas or city gas. The sweetened gas 22 is preheated in the combustion heating unit 105 and steam 23 is added to the sweetened gas 22, producing a gas stream 24. The gas stream 24 is directed to a pre-reforming unit 102 containing a steam reforming catalyst. Typically, the pre-reforming unit 102 is an adiabatic pre-reforming unit in which higher hydrocarbons react so that the pre-reforming gas 25 leaving the pre-reforming unit 102 contains no or very small amounts of higher hydrocarbons. The pre-reforming gas 25 is divided into a first portion 25a of the feed gas to the electrically heated reforming reactor 108 and a second portion 25b of the feed gas to the autothermal reforming reactor 109. Additional steam may be added to the first portion 25a of the feed gas ( Figure 1109). The first catalyst in the electrically heated reforming reactor 108 is a steam methane reforming catalyst, which is arranged to catalyze the steam methane reforming reaction in the electrically heated reforming reactor 108. The autothermal reforming reactor 109 also includes a steam methane reforming catalyst arranged to perform a steam methane reforming reaction. Air or oxygen 26 is also added to the autothermal reforming reactor to allow partial combustion of the second portion 25b of the feed gas to occur upstream of the second catalyst in the autothermal reforming reactor 109. The flow of the first synthesis gas 30a and the flow of the second synthesis gas 30b leave the electrically heated reforming reactor 108 and the autothermal reforming reactor 109, respectively, and merge into a combined synthesis gas flow 30 leaving the reforming section 110. The combined synthesis gas flow 30 is cooled in the heat exchanger 111 to a cooled combined synthesis gas flow 30'. The cooled combined synthesis gas flow 30' enters a post-processing unit, i.e., a water-gas shift unit 113, and the water-gas shift synthesis gas 32 leaves the water-gas shift unit. The water-gas shift synthesis gas 32 is cooled in the second heat exchanger 114 to a cooled water-gas shift synthesis gas 32', which enters a water separation unit 115, such as a flash separation unit, which is arranged to separate the cooled water-gas shift synthesis gas 32' into a condensate 27 and an intermediate synthesis gas 34. The intermediate synthesis gas 34 is a dry synthesis gas and enters a downstream section 116, which is arranged to process the synthesis gas into chemical products 40 and waste gas 45. The downstream section 116 includes, for example, an ammonia reactor that converts the intermediate synthesis gas 34 into ammonia, a methanol reactor that converts the intermediate synthesis gas 34 into methanol, or a Fischer-Tropsch reactor that converts the intermediate synthesis gas 34 into a mixture of higher hydrocarbons.

[0145] The exhaust gas 45 from the downstream section 116 is recycled as fuel to one or more burners of the combustion heating unit 105. The exhaust gas 45 is combined with a small amount of natural gas 46 to form a fuel gas 47, which is sent to one or more burners of the combustion heating unit 105. The combustion heating unit is arranged to provide heat to preheat the feed gas 21, the desulfurized gas 22 and the first part 25a and / or the second part 25b of the feed gas 25. Figure 1 In the embodiment, only the second part 25b of the feed gas 25 is heated in the combustion heating unit 105 before entering the autothermal reforming reactor 109. However, it is also conceivable that the first part 25a of the feed gas 25 is preheated in the combustion heating unit 105.

[0146] The heat exchange fluid 20 (eg, water) is used for heat exchange in the heat exchanger 111 , and the heated heat exchange fluid (eg, steam) is output as a stream 20 ′. A portion of the steam is used as steam 23 added to the sweetened gas 22 .

[0147] It should be noted that the chemical plant 100 typically includes other equipment, such as compressors, heat exchangers, etc.; however, Figure 1Such other devices are not shown in .

[0148] Figure 2 A chemical plant 200 according to one embodiment of the present invention is shown, wherein the reforming section 210 further comprises a fired steam methane reforming reactor 104 upstream of the autothermal reforming reactor 109 .

[0149] The chemical plant 200 includes a reforming section 210 having an electrically heated reforming reactor 108 containing a first catalyst, an autothermal reforming reactor 109 containing a second catalyst, and a combustion steam methane reforming reactor 104 containing a third catalyst. The combustion steam methane reforming reactor 104 is a side-fired tubular steam methane reforming reactor. Thus, the side-fired tubular steam methane reforming reactor includes a plurality of tubes 106 containing a third catalyst and a plurality of burners 103 arranged to heat the tubes 106. For clarity, Figure 2 Only one tube 106 is shown in FIG. 1 . Fuel is supplied to the burner 103 and burned to provide heat to the tube 106. The hot flue gas from the burner 103 is directed to the preheating section 205 of the combustion steam methane reforming reactor 104 and used to preheat the feed gas and steam. The electrically heated reforming reactor 108 is arranged in parallel with the combination of the combustion steam methane reforming reactor 104 and the autothermal reforming reactor 109. The electrically heated reforming reactor 108 is heated by the power supply 107.

[0150] The electrically heated reforming reactor 108 and the side-fired steam reforming reactor are arranged to receive the first and second portions 25a and 25b of the feed gas, respectively, and produce a first synthesis gas 30a and a pre-reformed feed gas 25b'. The pre-reformed feed gas 25b' leaves the combustion reforming reactor at a temperature between 700°C and 900°C and therefore does not require further preheating before entering the autothermal reforming reactor 109. Air or oxygen 26 is added to the autothermal reforming reactor 109. The autothermal reforming reactor 109 outputs a second synthesis gas 30b.

[0151] During operation of the chemical plant 200, a feed gas 21 containing hydrocarbons undergoes feed purification in the desulfurization unit 101 and becomes a sweetened gas 22. The feed gas 21 containing hydrocarbons is, for example, natural gas or city gas. The sweetened gas 22 is preheated in the preheating section 205 of the combustion steam methane reforming reactor 104, and steam 23 is added to produce a gas stream 24. The gas stream 24 is directed to a pre-reforming unit 102 containing a steam reforming catalyst. Typically, the pre-reforming unit 102 is an adiabatic pre-reforming unit in which higher hydrocarbons react so that the pre-reforming gas leaving the pre-reforming unit does not contain or contains very little higher hydrocarbons. The pre-reforming gas is divided into a first portion 25a of the feed gas to the electrically heated reforming reactor 108 and a second portion 25b of the feed gas to the combustion steam methane reforming reactor 104. The first catalyst in the electrically heated reforming reactor 108, the second catalyst in the autothermal reforming reactor 109 and the third catalyst in the combustion steam methane reforming reactor 104 are steam methane reforming catalysts, which are arranged to catalyze the steam methane reforming reactions in the electrically heated reforming reactor 108, the combustion steam methane reforming reactor 104 and the autothermal reforming reactor 109.

[0152] The electrically heated reforming reactor 108 produces a first syngas 30a, the combustion steam methane reforming reactor 104 produces a pre-reforming feed gas 25b', and the autothermal reforming reactor 109 provides a second syngas 30b. The first syngas 30a and the second syngas 30b are combined into a syngas stream 30, which is output from the reforming section 210 as a combined syngas stream 30.

[0153] The combined syngas stream 30 is cooled in the heat exchanger 111 into a cooled combined syngas stream 30'. The cooled combined syngas stream 30' enters a post-processing unit, namely a water-gas shift unit 113, and a water-gas shift syngas 32 leaves the water-gas shift unit 113. The water-gas shift syngas 32 is cooled in a second heat exchanger 114 into a cooled water-gas shift syngas 32', which enters a water separation unit, such as a flash separation unit 115. The cooled water-gas shift syngas 32' is separated into a condensate 27 and an intermediate syngas 34. The intermediate syngas 34 is a dry syngas, which is directed to a downstream section 116, which is arranged to process the intermediate syngas 34 into chemical products 40 and waste gas 45.

[0154] The downstream section 116 includes, for example, an ammonia reactor that converts the intermediate synthesis gas 34 into ammonia, a methanol reactor that converts the intermediate synthesis gas 34 into methanol, or a Fischer-Tropsch reactor that converts the intermediate synthesis gas 34 into a mixture of higher hydrocarbons.

[0155] The exhaust gas 45 from the downstream section 116 is recycled as fuel to the burner 103 burning the steam methane reforming reactor 104. The exhaust gas 45 is combined with a small amount of natural gas 46 to form a fuel gas 47, which is sent to the burner 103 burning the steam methane reforming reactor 104. The fuel gas 47 is burned in the burner 103, thereby heating the tubes 106 with the third catalyst. In the preheating section 205, the flue gas from the burner 103 provides heat for preheating the feed gas and is discharged from the preheating section 205 as flue gas 48. The heat exchange fluid 20 (e.g., water) is used for heat exchange in the heat exchanger 111, and the heated heat exchange fluid (e.g., steam) is output as a stream 20'. A portion of the steam is used as steam 23 added to the desulfurized gas 22.

[0156] It should be noted that the chemical plant 200 typically includes other equipment, such as compressors, heat exchangers, etc.; however, Figure 2 Such other devices are not shown in .

[0157] Figure 3 A chemical plant 300 according to an embodiment of the present invention is shown, wherein the reforming section includes four reforming reactors (i.e., an electrically heated reforming reactor 108 containing a first catalyst connected in parallel with a combination of a combustion steam methane reforming reactor 104 containing a third catalyst and an autothermal reforming reactor 109 containing a second catalyst), and a gas-heated steam methane reforming reactor containing a fourth catalyst.

[0158] The combustion steam methane reforming reactor 104 is a side-fired tubular steam methane reforming reactor that includes a plurality of tubes 106 containing a third catalyst and a plurality of burners 103 arranged to heat the tubes 106. For clarity, Figure 3 Only one tube is shown. Fuel is supplied to the burner 103 and burned to provide heat to the tube 106. The hot flue gas from the burner 103 is directed to the preheating section 205 of the combustion steam methane reforming reactor 104 and used to preheat the feed gas and steam. The electrically heated reforming reactor 108 is arranged in parallel with the combination of the upstream combustion steam methane reforming reactor 104 and the autothermal reforming reactor 109. The electrically heated reforming reactor 108 is heated by the power supply 107.

[0159] A first portion 25a of the feed gas 25 containing hydrocarbons is directed to the electrically heated reforming reactor 108 and a second portion 25b of the feed gas 25 containing hydrocarbons is directed to the side-fired steam reforming reactor. In the side-fired steam reforming reactor, the second portion 25b of the feed gas 25 is partially reformed into a pre-reformed feed gas 25b', which is sent to the autothermal reforming reactor 109 together with an oxidant gas (e.g., oxygen or air) stream.

[0160] During operation of the chemical plant 300, a feed gas 21 containing hydrocarbons undergoes feed purification in the desulfurization unit 101 and becomes a desulfurized gas 22. The feed gas 21 containing hydrocarbons is, for example, natural gas or city gas. The desulfurized gas 22 is preheated in the preheating section 205 of the combustion steam methane reforming reactor 104 and steam 23 is added to produce a gas stream 24. The gas stream 24 is directed to a pre-reforming unit 102 containing a steam reforming catalyst. Typically, the pre-reforming unit 102 is an adiabatic pre-reforming unit, in which higher hydrocarbons react so that the pre-reforming gas leaving the pre-reforming unit does not contain or contains very small amounts of higher hydrocarbons. The pre-reforming gas is divided into a first portion 25a of the feed gas to the electrically heated reforming reactor 108, a second portion 25b of the feed gas to the combustion steam methane reforming reactor 104, and a third portion 25c of the feed gas to the gas-heated steam methane reforming reactor 112.

[0161] The first catalyst in the electrically heated reforming reactor 108, the second catalyst in the autothermal reforming reactor, the third catalyst in the combustion steam methane reforming reactor 104 and the fourth catalyst in the gas heated steam methane reforming reactor 112 are steam methane reforming catalysts, which are arranged to catalyze the steam methane reforming reactions carried out in the electrically heated reforming reactor 108, the autothermal reforming reactor 109, the combustion steam methane reforming reactor 104 and the gas heated steam methane reforming reactor 112.

[0162] The first part 25a, the second part 25b and the third part 25c of the feed gas 25 are subjected to steam methane reforming in the electrically heated reforming reactor 108, the combustion steam methane reforming reactor 104, and the gas heated steam methane reforming reactor 112, respectively. The electrically heated reforming reactor 108 produces a first synthesis gas 30a, while the combustion steam methane reforming reactor 104 produces a pre-reformed feed gas 25b', which is further reformed in the autothermal reforming reactor 109 to provide a second synthesis gas 30b. The first synthesis gas 30a and the second synthesis gas 30b are combined into a synthesis gas stream 31, which is fed into the gas heated steam methane reforming reactor 112 to provide heat for the steam methane reforming reaction of the third part 25c of the feed gas entering the gas heated steam methane reforming reactor 112 from the other side.

[0163] The synthesis gas stream exits the gas heated steam methane reforming reactor and thence exits the reforming section 310 as a combined synthesis gas stream 30. The combined synthesis gas stream 30 is cooled in the heat exchanger 111 to form a cooled combined synthesis gas stream 30'.

[0164] The cooled combined synthesis gas stream 30' enters a water separation unit, such as a flash separation unit 115, which is arranged to separate the cooled combined synthesis gas stream 30' into a condensate 27 and an intermediate synthesis gas 34 in the form of a dry synthesis gas. The intermediate synthesis gas 34 enters a downstream section 116, which is arranged to process the dry synthesis gas into chemical products 40 and an off-gas 45. The downstream section 116 comprises, for example, an ammonia reactor for converting the intermediate synthesis gas 34 into ammonia, a methanol reactor for converting the intermediate synthesis gas 34 into methanol, or a Fischer-Tropsch reactor for converting the intermediate synthesis gas 34 into a mixture of higher hydrocarbons.

[0165] The exhaust gas 45 from the downstream section 116 is recycled as fuel to the burner 103 firing the steam methane reforming reactor 104. The exhaust gas 45 is combined with a small amount of natural gas 46 to form a fuel gas 47, which is sent to the burner 103 firing the steam methane reforming reactor 104. The fuel gas 47 is burned in the burner 103, thereby heating the tubes 106 with the third catalyst. In the preheating section 205, the flue gas from the burner 103 provides heat for preheating the feed gas and is discharged from the preheating section 205 as flue gas 48. The heat exchange fluid 20 (e.g., water) is used for heat exchange in the heat exchanger 111, and the heated heat exchange fluid (e.g., steam) is output as stream 20'.

[0166] It should be noted that the chemical plant 300 typically includes other equipment, such as compressors, heat exchangers, etc.; however, Figure 3 Such other devices are not shown in .

[0167] Figure 4 A chemical plant 400 according to one embodiment of the present invention is shown, wherein the reforming section 410 further comprises a gas steam methane reforming reactor 420 upstream of the autothermal reforming reactor 109 .

[0168] The second portion 25b of the feed gas is heated and pre-reformed in the gas steam methane reforming reactor 420 to provide a partially reformed feed gas, and the partially reformed feed gas is directed to the autothermal reforming reactor 109. The second synthesis gas 30b is used as a heating medium for heat exchange within the gas steam methane reforming reactor 420 to heat the second portion 25b of the feed gas, thereby providing a partially cooled second synthesis gas 30c. The partially cooled second synthesis gas 30c is combined with the first synthesis gas 30a to form a combined synthesis gas stream 30 leaving the reforming section 410.

[0169] Example 1

[0170] Table 1 shows an example of how to integrate an ATR and an electrical reformer to produce a combined syngas. First, by connecting the electrical reformer in parallel with the ATR, the syngas production capacity is increased without additional oxygen demand. Second, the modulus of the syngas can be changed, since the H2 / CO ratio outside the ATR is 2.3, in the given case, this ratio is increased to 2.6 in the combined syngas.

[0171] Table 1

[0172]

Claims

1. A chemical equipment, comprising: a reforming section arranged to receive a feed gas comprising hydrocarbons and to provide a combined synthesis gas stream, wherein the reforming section comprises: - an electrically heated reforming reactor containing a first catalyst, said electrically heated reforming reactor being arranged to receive a first portion of said feed gas and to produce a first synthesis gas stream, an autothermal reforming reactor connected in parallel with the electrically heated reforming reactor, the autothermal reforming reactor containing a second catalyst, the autothermal reforming reactor being arranged to receive a second portion of the feed gas and output a second synthesis gas stream, wherein the reforming section is arranged to output a combined synthesis gas stream comprising at least a portion of the first and / or second synthesis gas stream, - an optional post-treatment unit downstream of the reforming section, wherein the optional post-treatment unit is arranged to receive the combined synthesis gas stream and to provide a post-treated synthesis gas stream, a water separation unit arranged to separate the combined synthesis gas stream or the post-treated synthesis gas stream into water condensate and an intermediate synthesis gas, and a downstream section arranged to receive the intermediate synthesis gas and to process the intermediate synthesis gas into chemical products and waste gases; wherein the downstream section comprises a gas separation unit arranged to separate a stream of substantially pure CO2, H2 and / or CO from the intermediate syngas, thereby providing a refined syngas; and / or The downstream section includes an ammonia reactor that converts the intermediate synthesis gas or the refined synthesis gas into ammonia, a methanol reactor that converts the intermediate synthesis gas or the refined synthesis gas into methanol, or a Fischer-Tropsch reactor that converts the intermediate synthesis gas or the refined synthesis gas into a mixture of higher hydrocarbons.

2. The chemical equipment according to claim 1, characterized in that: The electrically heated reforming reactor comprises: a pressure shell housing an electric heating unit arranged to heat said first catalyst, wherein said first catalyst comprises a catalytically active material operable to catalyze steam reforming of said first portion of said feed gas, wherein said pressure shell has a design pressure of 5 to 45 bar, - a thermal insulation layer adjacent to at least a portion of the interior of the pressure vessel, and - at least two conductors electrically connected to the electric heating unit and to a power source placed outside the pressure vessel, Wherein the power source is sized to heat at least a portion of the first catalyst to a temperature of at least 800° C. by passing an electric current through the electric heating unit.

3. The chemical plant according to claim 2, wherein the electric heating unit comprises a macrostructure of an electrically conductive material, wherein the macrostructure carries a ceramic coating and the ceramic coating carries the catalytically active material.

4. The chemical plant according to any one of claims 1 to 3, further comprising: - a fired heater unit upstream of said autothermal reforming reactor, said fired heater unit being arranged to preheat said second portion of said feed gas, and - means for recirculating at least part of said exhaust gases from said downstream section as fuel to the combustion heater unit.

5. A chemical plant according to any one of claims 1 to 3, wherein the reforming section also includes a combustion steam methane reforming reactor located upstream of the autothermal reforming reactor, wherein the combustion steam methane reforming reactor includes one or more tubes containing a third catalyst; wherein the combustion steam methane reforming reactor includes one or more burners for providing heat for the steam methane reforming reaction within the one or more tubes; and wherein the chemical plant includes one or more burners for recycling at least part of the exhaust gas from the downstream section as fuel to the combustion steam methane reforming reactor; wherein the combustion steam methane reforming reactor is arranged to receive the second portion of the feed gas and provide a partially reformed second feed gas; and wherein the partially reformed second feed gas is introduced into the autothermal reforming reactor.

6. A chemical plant according to any one of claims 1 to 3, wherein the reforming section also includes a gas-heated steam methane reforming reactor connected in parallel with the combination of the electrically heated steam methane reforming reactor and the autothermal reforming reactor, wherein the gas-heated steam methane reforming reactor includes a fourth catalyst and is operable to receive a third portion of the feed gas and utilize at least a portion of the first and / or second synthesis gas streams as a heating medium in heat exchange within the gas-heated steam methane reforming reactor, and the gas-heated steam methane reforming reactor is arranged to produce a third synthesis gas stream and output the third synthesis gas stream from the reforming section as at least a portion of the combined synthesis gas stream.

7. A chemical plant according to any one of claims 1 to 3, wherein the reforming section also includes a gas-heated steam methane reforming reactor located upstream of the autothermal reforming reactor, wherein the gas-heated steam methane reforming reactor contains a fourth catalyst and is operable to utilize at least a portion of the second synthesis gas flow as a heating medium in heat exchange within the gas-heated steam methane reforming reactor, and the gas-heated steam methane reforming reactor is arranged to receive the second portion of the feed gas and provide a partially reformed second feed gas, wherein the partially reformed second feed gas is introduced into the autothermal reforming reactor.

8. The chemical plant of claim 7, wherein the gas heated steam methane reforming reactor is further operable to utilize at least a portion of the first synthesis gas stream as a heating medium in heat exchange within the gas heated steam methane reforming reactor.

9. A chemical plant according to any one of claims 1 to 3, wherein the post-treatment unit is a post-conversion unit, the post-conversion unit having an inlet allowing heated CO2 to be added to the combined synthesis gas flow upstream of the post-conversion unit and accommodating a fifth catalyst, the fifth catalyst having activity in catalyzing steam methane reforming, methanation and reverse water gas shift.

10. The chemical plant according to any one of claims 1 to 3, wherein the post-treatment unit is a water-gas shift unit arranged to perform a water-gas shift reaction.

11. The chemical plant according to claim 2, wherein the pressure shell has a design pressure of 30 to 45 bar.

12. The chemical plant of claim 2, wherein at least a portion of the first catalyst is heated to a temperature of at least 950°C.

13. The chemical plant of claim 2, wherein at least a portion of the first catalyst is heated to a temperature of at least 1050°C.

14. A method for producing a chemical product from a feed gas containing hydrocarbons in a chemical plant, the chemical plant comprising a reforming section, the reforming section comprising an electrically heated reforming reactor containing a first catalyst, an autothermal reforming reactor connected in parallel with the electrically heated reforming reactor, the autothermal reforming reactor containing a second catalyst, the method comprising the following steps: - introducing a first portion of the feed gas into the electrically heated reforming reactor and subjecting it to steam methane reforming to provide a first synthesis gas stream, - introducing a second portion of the feed gas into the autothermal reforming reactor and reforming it to provide a second synthesis gas stream, - outputting from said reforming section a combined synthesis gas stream comprising at least part of said first and / or second synthesis gas stream, - optionally, post-treating the combined synthesis gas stream in a post-treatment unit downstream of the electrically heated reforming reactor and the autothermal reforming reactor to provide a post-treated synthesis gas stream, - separating the combined synthesis gas stream or the post-treated synthesis gas stream into water condensate and an intermediate synthesis gas in a water separation unit downstream of the post-treatment unit, and - providing the intermediate synthesis gas to a downstream section arranged to receive the intermediate synthesis gas and to process the intermediate synthesis gas into chemical products and waste gases; wherein the method comprises separating a stream of substantially pure CO2, H2 and / or CO from the intermediate syngas, thereby providing a refined syngas in one or more gas separation units of the downstream section; and / or The method comprises: converting the intermediate synthesis gas into ammonia in an ammonia reactor in the downstream section, converting the intermediate synthesis gas into methanol in a methanol reactor in the downstream section, or converting the intermediate synthesis gas into a mixture of higher hydrocarbons in a Fischer-Tropsch reactor.

15. The method of claim 14, wherein the electrically heated reforming reactor comprises a pressure shell containing an electrically heated unit arranged to heat the first catalyst, wherein the first catalyst comprises a catalytically active material operable to catalyze steam reforming of the first portion of the feed gas, wherein the pressure shell has a design pressure of 5 to 45 bar; - a thermal insulation layer adjacent to at least a portion of the interior of the pressure vessel, and - at least two conductors electrically connected to the electric heating unit and to a power source placed outside the pressure vessel, The method further comprises the following steps: - pressurizing the first portion of the feed gas to a pressure of 5 to 45 bar upstream of the electrically heated reforming reactor, - passing an electric current through the electric heating unit, thereby heating at least a portion of the first catalyst to a temperature of at least 800°C.

16. The method according to claim 14 or 15, further comprising: - supplying fuel to a fired heater unit upstream of said autothermal reforming reactor, thereby preheating said second portion of said feed gas, and - Recirculating at least part of said exhaust gases from said downstream section as fuel to said combustion heater unit.

17. The method according to claim 14 or 15, wherein the reforming section further comprises a combustion steam methane reforming reactor upstream of the autothermal reforming reactor; wherein the steam methane reforming reactor comprises one or more tubes containing a third catalyst; wherein the combustion steam methane reforming reactor comprises one or more burners for providing heat for the steam methane reforming reaction in the one or more tubes; the method further comprises the following steps: - introducing said second portion of the feed gas into said combustion steam methane reforming reactor and subjecting it to steam methane reforming in the tubes of said combustion steam methane reforming reactor to provide a partially reformed second feed gas, - providing the partially reformed second feed gas to the autothermal reforming reactor, and - Recirculating at least part of said exhaust gases from said downstream section as fuel to one or more burners firing a steam methane reforming reactor.

18. The method according to claim 14 or 15, wherein the reforming section further comprises a gas heated steam methane reforming reactor connected in parallel with the combination of the electrically heated reforming reactor and the autothermal reforming reactor, wherein the gas heated steam methane reforming reactor comprises a fourth catalyst, and the method further comprises the following steps: - introducing a third portion of said feed gas into said gas heated steam methane reforming reactor, - utilizing at least part of said first and / or second synthesis gas stream as a heating medium in heat exchange within said gas heated steam methane reforming reactor, - producing a third synthesis gas stream over a fourth catalyst in a gas heated steam methane reforming reactor, and - outputting the third synthesis gas stream from the reforming section as at least a part of the combined synthesis gas.

19. The method according to claim 14 or 15, wherein the reforming section further comprises a gas heated steam methane reforming reactor upstream of the autothermal reforming reactor, wherein the gas heated steam methane reforming reactor comprises a fourth catalyst, the method further comprising the steps of: - introducing said second portion of the feed gas into said gas heated steam methane reforming reactor and performing steam methane reforming in said gas heated steam methane reforming reactor to provide a partially reformed second feed gas, - providing the partially reformed second feed gas to the autothermal reforming reactor, and - utilizing at least part of said second synthesis gas stream as a heating medium in heat exchange within said gas heated steam methane reforming reactor.

20. The method according to claim 19, further comprising the steps of: At least a portion of the first syngas stream is utilized as a heating medium in heat exchange within the gas heated steam methane reforming reactor.

21. A method according to claim 14 or 15, wherein the post-treatment unit is a post-conversion unit accommodating a fifth catalyst, wherein the fifth catalyst has the activity of catalyzing steam methane reforming, methanation and reverse water gas shift reactions, and wherein the method further comprises the step of introducing heated CO2 into the combined synthesis gas flow upstream of the post-conversion unit.

22. The method of claim 14 or 15, wherein the post-treatment unit is a water-gas shift unit and the step of post-treating the combined syngas stream comprises performing a water-gas shift reaction.

23. The process of claim 14 or 15, wherein the first portion of the feed gas is 5-20% by volume of the feed gas.

24. The method of claim 18, wherein the first portion of the feed gas is 5-10% by volume of the feed gas and the third portion of the feed gas is 5-10% by volume of the feed gas.

25. The method of claim 15, wherein the first portion of the feed gas is pressurized to a pressure of 30 to 45 bar upstream of the electrically heated reforming reactor.

26. The method of claim 15, wherein an electric current is passed through the electrical heating unit to heat at least a portion of the first catalyst to a temperature of at least 950°C.

27. The method of claim 15, wherein an electric current is passed through the electrical heating unit to heat at least a portion of the first catalyst to a temperature of at least 1050°C.

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