Shift reactor with center tube regulation and process

Abstract

The application discloses a shift reactor with center pipe adjustment and a process, and relates to the technical field of carbon one chemical industry.The application sets a center pipe without catalyst loading in a single shift reactor, divides the crude synthesis gas into a reaction shift path and a bypass non-shift path, integrates the two gas flows in the same reactor, and shares a set of downstream heat recovery, cooling and separation system.The center pipe is matched with an internal / external flow regulation actuator, which dynamically adjusts the bypass gas amount according to the real-time hydrogen-carbon ratio of the outlet synthesis gas, and accurately controls the shift reaction depth.The reactor can be designed as an isothermal or adiabatic, radial or axial structure.The isothermal type relies on the tube boiler feed water to remove heat and stabilize the bed temperature, and the adiabatic type simplifies the internal heat exchange structure.The application combines the advantages of the two traditional processes of full shift and partial shift, greatly reduces the number of pipelines, heat exchange and separation equipment, reduces the engineering investment and operation and maintenance cost, has the ability to stably control the hydrogen-carbon ratio under wide load and wide raw material component fluctuation, and is suitable for the carbon one chemical industry scene of coal-to-synthesis gas, natural gas-to-synthesis gas, industrial tail gas-to-synthesis gas and then synthesis of chemical products.

Description

Technical Field

[0001] This invention relates to the field of C1 chemical technology, and more specifically to a shift reactor with central tube regulation and the field of process technology. Background Technology

[0002] The syngas shift process is a core and critical step in the C1 chemical industry. Its main reaction is to convert carbon monoxide (CO) into hydrogen (H2). This process plays a vital role in the production of syngas from natural gas, coal, and industrial waste gas. Through the shift reaction, the hydrogen-to-carbon ratio of the syngas can be significantly adjusted, providing qualified feedstock gas for the production of downstream chemical products such as methanol, synthetic ammonia, ethylene glycol, and Fischer-Tropsch synthesis.

[0003] Currently, the mainstream syngas conditioning and conversion processes in the industry are mainly divided into two types: all-through process and conversion + non-conversion combined process.

[0004] The all-through process feeds all the crude syngas into a shift reactor for shift reaction. The resulting syngas is then treated by a heat recovery and separation system, followed by a cooling and separation system to obtain conditioned syngas. This process is relatively simple overall, requiring fewer pieces of equipment, a smaller footprint, and lower investment. However, the all-through process has poor resistance to fluctuations in operating conditions. When the composition of the feed gas fluctuates or the production load is adjusted, the shift depth is difficult to control precisely, easily leading to an excessive hydrogen-to-carbon ratio in the product gas, failing to meet the stringent hydrogen-to-carbon ratio requirements of downstream processes.

[0005] The shift + non-shift process divides the crude syngas into two paths: a shift path and a non-shift path. The shift path undergoes the shift reaction in a shift reactor, while the non-shift path bypasses it. Each path has its own heat recovery and separation system, as well as a cooling and separation system. The two paths are then combined to obtain conditioned syngas. This process controls the overall shift depth by adjusting the gas flow ratio between the shift and non-shift paths, exhibiting strong anti-interference capabilities, precise control of the shift depth, and good stability in hydrogen-to-carbon ratio adjustment. However, the equipment layout and piping connections of this process are complex, requiring two independent heat recovery systems, cooling and separation systems, and corresponding piping and valves, resulting in significantly higher investment and maintenance costs compared to the all-through process.

[0006] In summary, both existing mainstream shift reactor processes have significant technical drawbacks: the all-through process, while simple, suffers from poor adjustability; the shift + non-shift process, while offering precise adjustment, is complex and costly. Therefore, there is an urgent need to develop a novel shift reactor and process that can both simplify the process flow and achieve precise adjustment of the shift depth. Summary of the Invention

[0007] The purpose of this invention is to address the technical problems of poor control precision and weak resistance to operating condition fluctuations in all-through conversion processes, as well as the complex piping and high investment and maintenance costs of parallel conversion and non-conversion processes. This invention provides a conversion reactor and process with central pipe regulation. It integrates the conversion reaction path and the non-conversion bypass path within a single reactor, sharing a single downstream heat recovery and cooling separation system. This approach balances process simplicity with precise and adjustable hydrogen-to-carbon ratios, reducing equipment investment and maintenance costs, and improving the stability of the unit under a wide range of operating conditions. It combines the simplicity of an all-through process with the adjustment flexibility of a conversion + non-conversion process.

[0008] To achieve the above objectives, the present invention specifically adopts the following technical solution: One aspect of the present invention provides a shift reactor with central tube regulation, comprising a reactor shell, a central tube, a catalyst bed, a gas distribution assembly, and a flow regulation actuator; The shell has a crude syngas inlet and a syngas outlet at each end; The catalyst bed is a catalyst bed located inside the shell, and the catalyst bed is filled with a shift catalyst; The central tube is located inside the shell. The central tube is not filled with catalyst. One end of the central tube is connected to the crude syngas inlet, and the other end is connected to the syngas outlet. The gas distribution component is installed inside the housing to divide the crude syngas entering through the crude syngas inlet into two paths: one path enters the catalyst bed through the gas distribution component for shift reaction, and the other path directly enters the central tube for circulation; the two gas streams are mixed in the central tube or at the bottom of the central tube and then sent out through the syngas outlet. The gas flow regulating actuator is located inside or outside the central tube and is used to regulate the flow rate of crude syngas entering the central tube in order to control the depth of the conversion reaction.

[0009] In one embodiment, the reactor has an isothermal radial structure, and the gas distribution component is a cylindrical distributor disposed on the outside of the shell, with distribution holes formed on the cylindrical wall of the distributor; a cylindrical gas collector is disposed inside the cylindrical distributor, and the annular gap formed in the middle of the collector constitutes a central tube; the catalyst bed is disposed in the gap between the cylindrical distributor and the gas collector. The gas flow from the alternative path passes radially through the cylindrical distributor into the catalyst bed. After reacting in the catalyst bed, it flows into the gas collector and then into the central tube, where it mixes with the bypass gas flow in the central tube.

[0010] In one embodiment, a tube heat exchanger assembly is provided in the catalyst bed, with one end of the tube heat exchanger assembly connected to the boiler feedwater inlet and the other end connected to the steam-water outlet; the tube heat exchanger assembly is used to introduce boiler feedwater to remove the heat released by the conversion reaction, and the catalyst in the catalyst bed is filled in the gaps of the tube heat exchanger assembly.

[0011] In one embodiment, the reactor has an adiabatic axial structure, and the reactor shell cavity outside the central tube is filled with a layer of conversion catalyst to form a catalyst bed. The gas distribution component is located at the crude syngas inlet. After the crude syngas is distributed through the crude syngas inlet, the switching gas flows axially from top to bottom through the catalyst bed, while the bypass gas flows downward along the central tube. The two gas flows mix at the bottom of the reactor shell.

[0012] In one embodiment, the flow regulating actuator is an external flow regulating valve or a built-in throttling mechanism; An external flow regulating valve is installed on the reactor inlet pipeline, while a built-in throttling mechanism is fixedly installed inside the central tube.

[0013] In one embodiment, inert ball support layers are laid at both ends of the catalyst bed. The inert balls are used to support the conversion catalyst and prevent catalyst powder from clogging the gas channels.

[0014] A second aspect of the present invention provides a shift reaction process using a shift reactor with central tube regulation, wherein the syngas outlet is connected to a heat recovery and separation system and a cooling and separation system; the process includes the following steps: S1. Pass the crude syngas into the shift reactor; S2. The crude synthesis gas is divided into two streams by a gas distributor: one stream enters the catalyst bed through the gas distributor and comes into contact with the shift catalyst to undergo a shift reaction; the other stream flows directly into the central tube and does not participate in the shift reaction. S3. The two syngas streams are mixed in the reactor and then sent out through the syngas outlet. S4. The mixed syngas sequentially enters the heat recovery and separation system and the cooling and separation system for processing to obtain conditioned syngas. S5. The gas flow regulating actuator adjusts the flow rate of the coarse syngas entering the central pipe according to the real-time hydrogen-to-carbon ratio of the syngas at the syngas outlet, so as to control the total conversion depth.

[0015] Specifically, the cooling and separation system cools the mixed syngas to 40°C and then separates the condensate. The remaining condensate is then transported to the downstream acid gas removal unit.

[0016] In one embodiment, the transformation reaction is an adiabatic transformation reaction or an isothermal transformation reaction; The crude syngas flows radially or axially in the catalyst bed.

[0017] In one embodiment, in step S5, the gas flow regulating actuator adjusts the flow rate of the crude syngas entering the central pipe in real time according to the hydrogen-to-carbon ratio of the syngas at the syngas outlet; when the hydrogen-to-carbon ratio is higher than the set value, the inlet flow rate of the central pipe is increased; when the hydrogen-to-carbon ratio is lower than the set value, the inlet flow rate of the central pipe is decreased.

[0018] In one embodiment, the heat recovery and separation system includes a steam superheater, a steam waste boiler, a boiler feedwater preheater, and a demineralized water preheater connected in sequence to recover the heat of the mixed syngas in stages; the heat recovery and separation system is also equipped with one or more separators to separate the condensate generated during the heat recovery process.

[0019] The beneficial effects of this invention are as follows: 1. Significantly simplified process flow and reduced equipment investment. This invention integrates the two independent heat recovery and separation systems (conversion and non-conversion paths) into a single shared system by setting a central pipe inside the shift reactor. Both syngas streams pass through the same shift reactor and are mixed within it, sharing the same heat recovery and separation system and cooling and separation system downstream. This design significantly reduces the number of heat exchangers, separators, pipelines, and valves, greatly simplifying equipment layout and pipeline connections, and lowering equipment investment and maintenance costs.

[0020] 2. Precise and flexible conversion depth adjustment, with good stability in hydrogen-to-carbon ratio control. This invention, by installing a flow regulation actuator in the central pipe, can dynamically and precisely adjust the inlet flow rate of the syngas at the reactor outlet based on the real-time hydrogen-to-carbon ratio signal. When the composition of the feed gas fluctuates or the production load is adjusted, the actuator can respond quickly and adjust the gas flow ratio between the conversion path and the non-conversion path in a timely manner, thereby accurately controlling the total conversion depth and the outlet hydrogen-to-carbon ratio. Compared with the traditional all-through process, the present invention has significantly enhanced resistance to operating condition fluctuations.

[0021] 3. Strong applicability, adaptable to various conversion processes. The technical solution of this invention is applicable to both adiabatic and isothermal conversion processes; the process gas flow through the catalyst bed can be radial or axial. This broad applicability allows this invention to flexibly adapt to the conversion needs of different projects and operating conditions, and it has good prospects for widespread application.

[0022] 4. Flexible actuator placement facilitates engineering implementation. The central pipe flow regulating actuator of this invention can be externally mounted on the pipeline outside the reactor or internally mounted inside the central pipe. The external mounting method facilitates daily maintenance and repair, while the internal mounting method further saves external space and reduces pipeline connections. Both placement methods can be selected according to the specific project requirements, making engineering implementation flexible and convenient. Attached Figure Description

[0023] To more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of the present invention and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained from these drawings without creative effort.

[0024] Figure 1 This is a schematic diagram of a shift reactor (isothermal radial type) with central tube regulation.

[0025] Figure 2 This is a schematic diagram of a shift reactor (adiabatic circumferential type) with central tube regulation.

[0026] Figure 3 yes Figure 1 The overall process diagram.

[0027] Figure 4 yes Figure 2 The overall process diagram.

[0028] Figure label: 1. Reactor shell; 2. Flow regulation actuator; 3. Gas distribution components; 4. Gas collector; 5. Catalyst bed; 6. Inert spherical support layer; 7. Central tube; 8. Boiler feedwater inlet; 9. Soft drink outlet; 10. Shell and tube heat exchanger assembly; 11. Syngas outlet; 12. Crude syngas inlet. Detailed Implementation

[0029] To make the technical problems, technical solutions, and technical effects of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0030] Therefore, the following detailed description of the embodiments of the invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the invention without inventive effort are within the scope of protection of the invention.

[0031] It should be noted that similar reference numerals and letters in the following figures indicate similar items; therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures. Furthermore, the terms "first," "second," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0032] In the description of the embodiments of the present invention, it should be noted that the terms "inner", "outer", "upper", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship in which the product of the invention is usually placed when in use. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting the present invention.

[0033] One aspect of the present invention provides a shift reactor with a central tube 7 for regulation, comprising a reactor shell 1, a central tube 7, a catalyst bed 5, a gas distribution assembly 3, and a flow regulation actuator 2; The shell is provided with a crude syngas inlet 12 and a syngas outlet 11 at both ends; The catalyst bed 5 is disposed inside the shell and is filled with a shift catalyst. The central tube 7 is located inside the shell. The central tube 7 is not filled with catalyst. One end of the central tube 7 is connected to the crude syngas inlet 12, and the other end is connected to the syngas outlet 11. The gas distribution component 3 is installed inside the housing to divide the crude syngas entering through the crude syngas inlet 12 into two paths: one path enters the catalyst bed 5 through the gas distribution component 3 for conversion reaction, and the other path directly enters the central tube 7 for circulation; the two gas flows are mixed in the central tube 7 or at the bottom of the central tube 7 and then sent out through the syngas outlet 11. The gas flow regulating actuator 2 is located inside or outside the central tube 7 and is used to regulate the flow rate of the coarse synthesis gas entering the central tube 7 in order to control the depth of the conversion reaction.

[0034] In one embodiment, the reactor is an isothermal radial structure, the gas distribution component 3 is a cylindrical distributor located on the outside of the shell, and the distributor has distribution holes on its cylindrical wall; a cylindrical gas collector 4 is provided inside the cylindrical distributor, and the annular gap formed in the middle of the collector constitutes the central tube 7; the catalyst bed 5 is located in the gap between the cylindrical distributor and the gas collector 4. The gas flow from the switching path passes radially through the cylindrical distributor into the catalyst bed 5. After reacting in the catalyst bed 5, it flows into the gas collector 4 and then into the central tube 7, where it mixes with the bypass gas flow in the central tube 7.

[0035] In one embodiment, a tube heat exchange assembly 10 is provided in the catalyst bed 5. One end of the tube heat exchange assembly 10 is connected to the boiler feedwater inlet 8, and the other end is connected to the steam-water outlet 9. The tube heat exchange assembly 10 is used to introduce boiler feedwater to remove the heat released by the conversion reaction. The catalyst in the catalyst bed 5 is filled in the gaps of the tube heat exchange assembly 10.

[0036] In one embodiment, the reactor is an adiabatic axial structure, and the reactor shell 1 outside the central tube 7 is filled with a layered shift catalyst to form a catalyst bed 5. The gas distribution component 3 is located at the crude syngas inlet 12. After the crude syngas is distributed through the crude syngas inlet 12, the switching gas flows axially from top to bottom through the catalyst bed 5, and the bypass gas flows down along the central pipe 7. The two gas flows mix at the bottom of the reactor shell 1.

[0037] In one embodiment, the flow regulating actuator 2 is an external flow regulating valve or a built-in throttling mechanism; An external flow regulating valve is installed on the pipeline outside the reactor inlet 12, and a built-in throttling mechanism is fixedly installed in the internal pipe section of the central pipe 7.

[0038] In one embodiment, inert ball support layers 6 are laid at both ends of the catalyst bed 5. The inert balls are used to support the catalyst and prevent catalyst powder from blocking the gas passage.

[0039] A second aspect of the present invention provides a shift reaction process using a shift reactor with a central tube 7 for regulation. The shift reactor with the central tube 7 is described above, and the syngas outlet 11 is connected to a heat recovery and separation system and a cooling and separation system. The process is characterized by the following steps: S1. Pass the crude syngas into the shift reactor; S2. The crude synthesis gas is divided into two streams by a gas distributor: one stream enters the catalyst bed 5 through the gas distributor and comes into contact with the shift catalyst to undergo a shift reaction; the other stream flows directly into the central tube 7 and does not participate in the shift reaction. S3. The two syngas streams are mixed in the reactor and then sent out through syngas outlet 11. S4. The mixed syngas sequentially enters the heat recovery and separation system and the cooling and separation system for processing to obtain conditioned syngas. S5. The gas flow regulating actuator 2 adjusts the flow rate of the crude syngas entering the central pipe 7 according to the real-time hydrogen-carbon ratio of the syngas at the syngas outlet 11, so as to control the total conversion depth.

[0040] Specifically, the cooling and separation system cools the mixed syngas to 40°C and then separates the condensate. The remaining condensate is then transported to the downstream acid gas removal unit.

[0041] In one embodiment, the transformation reaction is an adiabatic transformation reaction or an isothermal transformation reaction; The crude syngas flows radially or axially in catalyst bed 5.

[0042] In one embodiment, in step S5, the gas flow regulating actuator 2 adjusts the flow rate of the crude syngas entering the central pipe 7 in real time according to the hydrogen-to-carbon ratio of the syngas at the syngas outlet 11; when the hydrogen-to-carbon ratio is higher than the set value, the inlet flow rate of the central pipe 7 is increased; when the hydrogen-to-carbon ratio is lower than the set value, the inlet flow rate of the central pipe 7 is decreased.

[0043] In one embodiment, the heat recovery and separation system includes a steam superheater, a steam waste boiler, a boiler feedwater preheater, and a demineralized water preheater connected in sequence to recover the heat of the mixed syngas in stages; the heat recovery and separation system is also equipped with one or more separators to separate the condensate generated during the heat recovery process.

[0044] Implementation Case 1 by Figure 1 Taking the structure shown as an example, this embodiment provides an isothermal radial change reactor with central tube regulation, and the flow regulation actuator is external.

[0045] The reactor includes a reactor shell 1, and a crude syngas inlet 12, a syngas outlet 11, a boiler feedwater inlet 8, and a steam-water outlet 9, respectively installed on the reactor shell 1. A flow regulating actuator 2, which is a flow regulating valve, is installed on the syngas inlet pipeline and directly connects to the central pipe.

[0046] Inside the reactor shell 1, a cylindrical gas distributor is located near the outer side, and a cylindrical gas collector 4 is located near the inner side. The annular gap formed in the middle of the gas collector 4 is the central tube 7. A tube-and-shell heat exchange assembly 10 is evenly arranged in the gap between the gas distributor and the gas collector 4, and a shift catalyst is filled between the tubes. An inert spherical support layer is provided at the bottom of the catalyst bed 5 to support the catalyst.

[0047] Small holes are provided in the gas distributor. The crude syngas destined for conversion enters the reactor and then flows radially through the catalyst bed via the gas distributor, where it undergoes a conversion reaction. The heat released by the reaction is promptly carried away by the boiler feedwater filling the tube heat exchanger assembly 10, producing steam as a byproduct. Because the heat of reaction is removed promptly, the temperature difference between the upper and lower parts of the catalyst bed 5 is small, hence the term isothermal reaction. The converted syngas flows radially, is collected by the collector, and then enters the central tube.

[0048] The other crude syngas, after its flow rate is controlled by a flow regulating valve, enters directly into the central tube 7 without passing through the catalyst bed 5 and does not participate in the shift reaction. The two syngas streams mix in the central tube 7 and then enter the downstream heat recovery and separation system and cooling and separation system through the syngas outlet 11.

[0049] Under the action of the shift catalyst, the crude syngas will undergo a shift reaction, and the equation for the shift reaction is as follows: CO + H₂O = CO₂ + H₂ + Heat; This reaction can convert CO into H2, and the generated CO2 can be removed by a subsequent acid gas removal system, thereby adjusting the hydrogen-to-carbon ratio of the syngas.

[0050] The flow regulating valve of the central pipe 7 can regulate the flow rate of the crude syngas entering the central pipe 7. When the hydrogen-to-carbon ratio in the outlet syngas is higher than the required value, the flow rate of the crude syngas directly entering the central pipe is increased by the regulating valve to reduce the conversion depth; conversely, when the hydrogen-to-carbon ratio at the outlet is lower than the required value, the inlet flow rate of the central pipe is reduced.

[0051] Working Principle: The crude syngas enters the reactor through the inlet and splits into two streams. One stream flows evenly into the catalyst bed 5 through small holes in the gas distributor. Under the action of the catalyst, it flows radially through the bed, where CO and H2O undergo a conversion reaction to produce H2 and CO2. The heat released by the reaction is absorbed by the boiler feedwater in the tube heat exchange assembly 10, producing steam as a byproduct. The converted gas is collected by the gas collector 4 and then enters the central tube 7. The other stream of crude syngas, after its flow rate is controlled by a flow regulating valve, directly enters the central tube 7 without passing through the catalyst bed. The two streams of gas mix in the central tube 7 and are then discharged through the syngas outlet 11. The flow regulating valve adjusts the amount of crude syngas entering the central tube in real time according to the hydrogen-to-carbon ratio of the outlet syngas, thereby controlling the overall conversion depth.

[0052] Implementation Case 2 by Figure 2 Taking the structure shown as an example, this embodiment provides an adiabatic axial change reactor with central tube adjustment. The flow adjustment actuator 2 is built-in and is installed inside the central tube 7.

[0053] The reactor includes a reactor shell 1, and a crude syngas inlet 12 and a syngas outlet 11 respectively disposed on the reactor shell 1.

[0054] A central tube 7 is provided in the reactor shell 1, and the gaps outside the central tube 7 are filled with shift catalyst. After the crude syngas enters, it is first distributed by a gas distributor. One stream of crude syngas enters the catalyst bed 5, flows axially from top to bottom, contacts the catalyst, undergoes a shift reaction, and releases heat, causing the syngas temperature to rise; this is therefore called an adiabatic reaction. The other stream of crude syngas passes directly through the central tube without contacting the catalyst. The two streams of syngas are mixed and collected at the bottom of the reactor, then discharged from the outlet, and subsequently pass through a downstream heat recovery and separation system, and a cooling and separation system.

[0055] A flow regulating actuator 2 is provided inside the central tube 7, which can regulate the flow rate entering the central tube 7, thereby regulating the total conversion depth and the hydrogen-to-carbon ratio of the syngas outlet 11.

[0056] Working principle: After the crude syngas enters the reactor through the top inlet, it is distributed into two streams by the gas distributor. One stream flows downward into the catalyst bed 5, where it flows axially from top to bottom under the action of the catalyst and undergoes a shift reaction, converting CO into H2. The exothermic reaction raises the gas temperature. The other stream flows directly into the central tube 7 downward without participating in the reaction. The two streams mix at the bottom of the reactor and are then discharged through the outlet. The flow regulation actuator 2 in the central tube 7 adjusts the gas inlet flow in real time based on the hydrogen-to-carbon ratio signal at the outlet, controlling the shift reaction depth.

[0057] Implementation Case 3 like Figure 3 As shown, this embodiment provides a shift reaction process for a shift reactor with central tube regulation, as detailed below: After preliminary purification, the crude syngas enters the shift reactor with central tube 7. At the reactor inlet, the crude syngas is divided into two paths: one path enters the catalyst bed through a gas distributor for shift reaction, and the other path directly enters central tube 7 as a non-shift gas bypass.

[0058] The mixed syngas from the reactor outlet enters the heat recovery and separation system. This system includes a series of heat exchange devices connected in sequence, such as a steam superheater, a steam waste boiler, a boiler feedwater preheater, and a demineralized water preheater, to recover the higher heat from the syngas stage by stage. During the heat recovery process, separators are installed at appropriate locations to promptly separate the condensate, depending on the moisture content of the syngas.

[0059] After heat recovery, the syngas enters the cooling and separation system, and is finally cooled to about 40°C by water. After the condensate is separated, the conditioned syngas is obtained and sent to the downstream purification unit.

[0060] Throughout the operation, the flow regulating actuator 2 receives the hydrogen-to-carbon ratio analysis signal of the syngas at the reactor outlet in real time. When the hydrogen-to-carbon ratio is higher than the set value, the flow regulating actuator 2 increases the opening of the central tube, increasing the non-shift gas volume; when the hydrogen-to-carbon ratio is lower than the set value, the flow regulating actuator 2 decreases the opening of the central tube, reducing the non-shift gas volume. Through this closed-loop control, precise and automatic adjustment of the shift depth is achieved.

[0061] Implementation Case 4 This embodiment describes the adjustment process of the present invention under conditions of fluctuation in the composition of the raw gas.

[0062] When the feedstock in the upstream gasification section changes, causing the CO content in the crude syngas entering the conversion process to increase, if the original operating conditions remain unchanged, the conversion reaction will intensify, and the hydrogen-to-carbon ratio of the syngas at the outlet will decrease, possibly falling below the requirements of downstream production.

[0063] In this situation, the flow regulation actuator 2 of the present invention automatically increases the inlet flow rate of the central tube 7 based on the real-time detection signal of the outlet hydrogen-to-carbon ratio, allowing more crude syngas to bypass the central tube 7 directly without participating in the shift reaction. Because the amount of reactant gas entering the catalyst bed 5 decreases, the total shift depth decreases accordingly, and the outlet hydrogen-to-carbon ratio returns to the set value.

[0064] Conversely, when the CO content in the crude syngas decreases, the flow regulating actuator 2 automatically reduces the inlet flow rate of the central pipe 7, increases the amount of gas entering the catalyst bed 5, improves the conversion depth, and ensures that the outlet hydrogen-to-carbon ratio is maintained within the required range.

[0065] Through the above dynamic adjustment, the present invention can maintain a stable hydrogen-to-carbon ratio in the outlet syngas even when the composition of the feed gas fluctuates frequently.

Claims

1. A shift reactor with central tube regulation, characterized in that: Includes reactor shell, central tube, catalyst bed, gas distribution assembly, and flow regulation actuator; The shell is provided with a crude syngas inlet and a syngas outlet at both ends; The catalyst bed is a catalyst bed disposed within the shell, and the catalyst bed is filled with a shift catalyst; The central tube is disposed inside the housing. The central tube is not filled with catalyst. One end of the central tube is connected to the crude syngas inlet, and the other end is connected to the syngas outlet. The gas distribution assembly is disposed within the housing to divide the crude syngas entering through the crude syngas inlet into two paths: one path enters the catalyst bed through the gas distribution assembly for a shift reaction, and the other path directly enters the central tube for circulation; the two gas streams are mixed in the central tube or at the bottom of the central tube and then sent out through the syngas outlet. The gas flow regulating actuator is located inside or outside the central tube and is used to regulate the flow rate of the coarse synthesis gas entering the central tube in order to control the transformation reaction depth.

2. The shift reactor with central tube regulation according to claim 1, characterized in that: The reactor has an isothermal radial structure. The gas distribution assembly is a cylindrical distributor located on the outside of the shell, with distribution holes on the cylindrical wall of the distributor. A cylindrical gas collector is installed inside the cylindrical distributor, and the annular gap formed in the middle of the collector constitutes the central tube. The catalyst bed is located in the gap between the cylindrical distributor and the gas collector. The alternating flow gas passes radially through the cylindrical distributor into the catalyst bed, reacts in the catalyst bed, and then flows into the gas collector and then into the central tube, where it mixes with the bypass flow gas in the central tube.

3. A shift reactor with central tube regulation according to claim 2, characterized in that: The catalyst bed is equipped with a tube heat exchanger assembly, one end of which is connected to the boiler feedwater inlet and the other end of which is connected to the steam-water outlet. The tube heat exchanger assembly is used to introduce boiler feedwater to remove the heat released by the conversion reaction, and the catalyst in the catalyst bed is filled in the gaps of the tube heat exchanger assembly.

4. A shift reactor with central tube regulation according to claim 1, characterized in that: The reactor is an adiabatic axial structure, and the reactor shell cavity outside the central tube is filled with a layered shift catalyst to form the catalyst bed. The gas distribution component is located at the crude syngas inlet. After the crude syngas is distributed through the crude syngas inlet, the switching gas flows axially from top to bottom through the catalyst bed, and the bypass gas flows downward along the central tube. The two gas flows are mixed at the bottom of the reactor shell.

5. A shift reactor with central tube regulation according to claim 1, characterized in that: The flow regulation actuator is an external flow regulation valve or a built-in throttling mechanism; The external flow regulating valve is installed on top of the catalyst bed inside the reactor shell, and the built-in throttling mechanism is fixedly installed inside the central tube section.

6. A shift reactor with central tube regulation according to claim 1, characterized in that: Inert ball support layers are laid at both ends of the catalyst bed. The inert balls are used to support the shift catalyst and prevent catalyst powder from clogging the gas passage.

7. A shift reaction process using a shift reactor with central tube regulation, comprising the shift reactor with central tube regulation as described in any one of claims 1 to 5, wherein the syngas outlet is connected to a heat recovery and separation system and a cooling and separation system; characterized in that: Includes the following steps: S1. The crude syngas is introduced into the shift reactor; S2. The crude synthesis gas is divided into two paths by the gas distributor: one path enters the catalyst bed through the gas distributor and contacts the shift catalyst to undergo a shift reaction; the other path directly enters the central tube and does not participate in the shift reaction. S3. The two syngas are mixed in the central tube of the reactor and then sent out through the syngas outlet. S4. The mixed syngas is sequentially fed into a heat recovery and separation system and a cooling and separation system for processing to obtain conditioned syngas. S5. The gas flow rate regulating actuator adjusts the flow rate of the coarse syngas entering the central pipe according to the real-time hydrogen-to-carbon ratio of the syngas at the syngas outlet, so as to control the total conversion depth.

8. The shift reaction process of a shift reactor with central tube regulation according to claim 7, characterized in that: The transformation reaction is an adiabatic transformation reaction or an isothermal transformation reaction; The crude syngas flows radially or axially in the catalyst bed.

9. The shift reaction process of a shift reactor with central tube regulation according to claim 7, characterized in that: In step S5, the gas flow regulating actuator adjusts the flow rate of the crude syngas entering the central pipe in real time according to the hydrogen-to-carbon ratio of the syngas at the syngas outlet; when the hydrogen-to-carbon ratio is higher than the set value, the inlet flow rate of the central pipe is increased; when the hydrogen-to-carbon ratio is lower than the set value, the inlet flow rate of the central pipe is decreased.

10. The shift reaction process of a shift reactor with central tube regulation according to claim 7, characterized in that: The heat recovery and separation system includes a steam superheater, a steam waste boiler, a boiler feedwater preheater, and a demineralized water preheater connected in sequence, for recovering the heat of the mixed syngas in stages; the heat recovery and separation system is also equipped with one or more separators for separating the condensate generated during the heat recovery process.

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