High-productivity slurry bed Fischer-Tropsch synthesis reactor, Fischer-Tropsch synthesis system and Fischer-Tropsch synthesis method

Abstract

The invention discloses a high-productivity slurry bed Fischer-Tropsch synthesis reactor, a Fischer-Tropsch synthesis system and a Fischer-Tropsch synthesis method. The reactor comprises a reactor cylinder and an internal component arranged in the reactor cylinder, the inner component comprises a bottom gas distributor, a first-section heat removal pipe for removing heat of the reactor, a lower gas distributor, a second-section heat removal pipe for removing heat of the reactor, and an inner filter for filtering a catalyst in a heavy component product to be discharged out of the reactor, which are sequentially arranged from bottom to top; the three-section heat removal pipe is used for removing heat of the reactor; the top cyclone hydraulic separator is used for separating a catalyst entrained in tower gas discharged from the top of the tower; the bottom gas distributor is positioned at a lower sealing head of the reactor barrel, the opening of a gas outlet hole of the bottom gas distributor is downward, and circulating gas with relatively reduced effective gas content is introduced; and the opening of the air outlet hole of the lower distributor is downward. The reactor disclosed by the invention solves the problem of temperature runaway at the bottom of the reactor and is beneficial to improving the productivity and the production efficiency of the reactor.

Description

Technical Field

[0001] The present invention relates to the field of Fischer-Tropsch synthesis, and particularly to a high-production-capacity slurry-phase Fischer-Tropsch synthesis reactor, a high-energy-efficiency Fischer-Tropsch synthesis system and method. Background Art

[0002] With the continuous increase in oil prices in recent years, people have paid more and more attention to the development of technologies for producing alternative oil products. Syngas is produced from coal, natural gas or other substances, and then, according to the requirements of the Fischer-Tropsch synthesis catalyst for syngas, the syngas is processed through water-gas shift and syngas purification processes. Using the processed syngas as raw material, hydrocarbons are produced through Fischer-Tropsch synthesis, while water and oxygenates are by-produced. Then, mature petroleum processing technologies are used for processing to produce high-quality environmentally friendly oil products. The development of Fischer-Tropsch synthesis technology is of great significance for the development of production technologies for alternative oil products.

[0003] The Fischer-Tropsch synthesis reactor is the core reactor of Fischer-Tropsch synthesis technology. At present, three-phase slurry-phase reactors that can produce more hydrocarbon products are widely used at home and abroad. The slurry-phase reactor has the advantages of uniform and easy-to-control temperature, wide gas velocity operation range, high content of heavy components in the product, and online replacement of the catalyst. The slurry-phase reactor used in industry is composed of a reactor cylinder body, a bottom gas distributor, a middle heavy wax internal filter, a top hydrocyclone separator, a full-column heat extraction pipe fitting, etc.

[0004] The Fischer-Tropsch synthesis reaction is a strongly exothermic reaction. The distribution of Fischer-Tropsch synthesis products and the activity of the catalyst are very sensitive to temperature. Maintaining a relatively constant temperature in the reactor is very important for the smooth progress and safe operation of the reaction in the slurry-phase reactor. Therefore, when carrying out the Fischer-Tropsch synthesis reaction, it is necessary to uniformly and quickly remove the heat in the slurry-phase reactor outside the reactor. During the actual operation process, local overheating and temperature runaway phenomena will also occur in the slurry-phase reactor, which will lead to problems such as rapid deactivation of the catalyst and reduction of the yield of the target product. Therefore, the heat extraction design in the reactor not only needs to consider uniformly and quickly removing the heat outside the reactor, but also needs to consider that when local overheating and temperature runaway occur, there are sufficient measures and methods to timely and effectively remove more heat brought by the temperature runaway, so as to ensure the safety of reactor operation and improve the yield of the target product.

[0005] The Fischer-Tropsch synthesis supporting process system is used for the separation and recovery of reaction products, and consists of a series of equipment such as heat exchangers, gas-liquid separators, and compressors. The typical industrial process flow is as follows: the heavy wax component is separated by an internal filter; the gas leaving the tower is heat-exchanged with the gas entering the tower and then enters the heavy oil separator to separate the heavy oil component; the gas from the heavy oil separator enters the light oil separator after air cooling. Part of the gas is mixed with fresh gas by a recycle compressor to become the gas entering the tower, and part enters the hot potassium carbonate decarbonization system. The liquid enters the oil-water separator to separate the light oil component and synthesis water; part of the decarbonized gas is mixed with the recycle gas for recycling, and part enters the subsequent low-temperature oil washing unit to recover LPG, and the tail gas enters the hydrogen recovery unit; the roughly separated heavy wax, heavy oil, and light oil enter the stripping column for fractionation to form stable intermediate oil products, and then enter the oil processing unit to form the target products; the synthesis water enters the synthesis water treatment unit to recover mixed alcohols and discharge wastewater.

[0006] The energy conversion efficiency (hereinafter referred to as "energy efficiency") is an important indicator for the development of the modern coal chemical industry. The current operating energy efficiency of typical indirect coal liquefaction industrial systems is 42-45%. Analyzing the main process units of its process flow, it is found that the energy efficiency of the oil synthesis unit (including Fischer-Tropsch synthesis, oil processing, and tail gas treatment, etc.) is only about 71%, which is an important factor for the relatively low overall energy efficiency of indirect coal liquefaction. Therefore, optimizing the current oil synthesis process flow is an important direction to improve the system energy efficiency. Among them, the Fischer-Tropsch synthesis part is the main factor for the relatively low energy efficiency of the oil synthesis unit and is the key position for process flow optimization. Especially after the production capacity of a single reactor is increased, the necessity of sharing devices such as stripping, decarbonization, and low-temperature oil washing by multiple reactors in the existing Fischer-Tropsch synthesis process system is reduced, and the process system suitable for high-production-capacity slurry bed reactors may be quite different from the current process flow.

[0007] CN101396647A discloses a Fischer-Tropsch synthesis gas-liquid-solid three-phase suspension bed reactor and a supporting system, and details the structure and size design of the reactor as well as the detailed design and layout methods of internal components such as gas distributors, heat extraction tubes, internal filters, draft tubes, and top condensation reflux devices. This reactor and system are applicable to large-scale industrial Fischer-Tropsch synthesis. When the inner diameter is 10m, the C 3 + The oil production capacity is 70-100t / h. However, in actual industrial operation, after increasing the raw material gas treatment volume to 115% (the production capacity reaches 72.5t / h), it is difficult to increase the production capacity by increasing the intake gas volume. The reason is that under the condition of high catalyst loading, the catalyst concentration at the bottom of the reactor is relatively high and the current activity level of the catalyst is also relatively high. Under the condition of high raw material gas intake, the Fischer-Tropsch synthesis reaction at the bottom of the reactor is intense, the heat release increases, but the heat extraction capacity of the reactor is limited, resulting in too high a bottom temperature, exceeding the normal operating range of the catalyst. Therefore, the intake gas flow rate of the raw material gas cannot be increased continuously.

[0008] CN111790319B discloses a Fischer-Tropsch synthesis slurry bed reactor and a Fischer-Tropsch synthesis method. Inside the reactor body, a heat exchanger component, a filtration component, and a demisting component are arranged axially from bottom to top. The heat exchanger components and the filtration components are arranged alternately, and multiple baffles are arranged axially on the inner side wall of the reactor. This reactor can improve the bed flow, effectively control the flow rate of the slurry, reduce the shear force generated by the backmixing of the slurry in the catalyst bed, reduce catalyst loss, and at the same time reduce the entrainment of mist in the foam layer, making the reactor operate more stably. However, it is still difficult to solve the problem of overheating at the bottom of the reactor caused by high production capacity and high inlet gas.

[0009] CN109126640B discloses a Fischer-Tropsch synthesis slurry bed reaction system, which focuses on the heat removal system of the slurry bed reactor. This system treats the runaway temperature situation of the reactor by introducing a cold water source into the heat removal circulating water pipeline and setting baffles in the heat removal pipe to extend the water flow time, timely and effectively removing the excess heat brought by the runaway temperature, thereby ensuring the yield of the target product and improving the safety of the device operation. However, in the actual application of increasing production capacity, it is still difficult to timely remove the heat at the bottom of the reactor, and overheating is likely to occur.

[0010] CN114225844B discloses a multi-stage slurry bed reactor and its working method. The multi-stage reactor is provided with reaction zones at both ends including an upper outer casing and a lower outer casing. The recycle gas enters the reactor from the conical gas distributor and the bottom inlet of the enlarged section respectively, instead of entering from the bottom to reduce the conversion rate of fresh gas in the lower reaction section. The fresh gas enters from the bottom of the reactor. The enlarged section can reduce the entrainment of relatively active coarse catalyst from the gas outlet by reducing the gas velocity and increasing the gas-liquid separator, preventing blockage of subsequent processes or reducing their service life. The recycle gas enlarged section reduces the severity of the reaction, which can not only prevent local overheating and non-uniform temperature but also reduce the heat removal. The entire reactor takes heat in multiple stages, one stage in the lower reaction section and two to three stages in the upper part, and there are two liquid wax filtration devices, one at the top and one at the bottom. However, when actually increasing the production capacity of the reactor, the position where the reaction is intense is at the bottom of the reactor. This method is difficult to solve the problem of runaway temperature at the bottom caused by increasing the production capacity of the reactor. Instead, it will cause the reaction at the bottom to be more intense and exacerbate the problem of runaway temperature at the bottom.

[0011] CN107254327B discloses a slurry bed Fischer-Tropsch synthesis oil process. In this process, a heat exchanger tube group is arranged at the top of the slurry bed reactor. By using the recycled tail gas to absorb heat, the outlet temperature of the reaction tail gas is reduced, the thermal utilization rate of the system is improved, the condensation of high-carbon hydrocarbons in the reaction tail gas is increased, the entrainment of the reaction tail gas to product droplets can be reduced, the output of the value-added product wax is increased, and at the same time, the fine powder catalyst is retained in the slurry bed reactor, improving the utilization rate of the fine powder catalyst. Although arranging the heat exchanger tube group at the top of the slurry bed reactor and using the recycled tail gas to absorb heat to reduce the outlet temperature of the reaction tail gas has a certain effect on energy conservation and consumption reduction, its effect on improving the overall energy efficiency is relatively small.

[0012] CN112094663B discloses a method and device for separating Fischer-Tropsch synthesis products. This separation method can reduce the energy consumption of the device and achieve precise separation of products by adding equipment such as an outlet gas separator and an intermediate oil filter in the original industrial process. In the preferred case, the material to be subjected to stripping separation is filtered, avoiding the catalyst in the Fischer-Tropsch synthesis products from entering the downstream pipeline and ensuring the long-term stable operation of the device. However, it is difficult to see an obvious effect in terms of energy conservation and consumption reduction and improving energy efficiency.

[0013] CN115449398A discloses a Fischer-Tropsch synthesis product separation system. Compared with the original industrial process, this system reduces the steps of heavy wax and heavy oil entering the stripping column for re-separation. The light oil enters the stripping column for precise separation, achieving the precise separation of Fischer-Tropsch synthesis products. In addition to intermediate products such as heavy wax and heavy oil, the Fischer-Tropsch synthesis device can produce three different products, namely light oil (C12-C22), naphtha (C6-C12), and light hydrocarbons (C3-C6), as well as synthesis water, providing good raw materials for various downstream product processing schemes. At the same time, a reboiler is arranged at the bottom of the stripping column to achieve the efficient recovery of the heat of the high-temperature heavy wax in Fischer-Tropsch synthesis, reducing the energy consumption of the device; realizing the direct external delivery of Fischer-Tropsch synthesis products, reducing secondary pressurization facilities such as pumps, and reducing the energy consumption of the device. However, its heavy wax and heavy oil lack re-separation, the separation of heavy components is poor, the separation of light components is fine, but the overall output is low, and the significance of fine separation is small but it increases the energy consumption.

[0014] With the development of Fischer-Tropsch synthesis catalysts and process technologies, more active industrial Fischer-Tropsch synthesis catalysts have been developed, and at the same time, higher requirements have been put forward for the oil production capacity of a single reactor. In order to improve the production capacity of the existing industrial slurry bed reactor, it is necessary to increase the processing volume of the raw material gas and increase the catalyst concentration to ensure the reaction activity. Summary of the Invention

[0015] The object of the present invention is to provide a high-capacity slurry-phase Fischer-Tropsch synthesis reactor, a high-energy-efficiency Fischer-Tropsch synthesis system and method, so as to solve the problem of runaway temperature at the bottom of the reactor, improve the production capacity and production efficiency of the reactor, reduce energy consumption at the same time, and improve the energy conversion efficiency of the process system.

[0016] To achieve one aspect of the above-mentioned invention object, the present invention adopts the following technical solutions:

[0017] A high-capacity slurry-phase Fischer-Tropsch synthesis reactor, comprising a reactor cylinder body and internal components arranged in the reactor cylinder body; wherein,

[0018] The internal components include a bottom gas distributor, a first-stage heat extraction pipe for removing heat from the reactor, a lower gas distributor, a second-stage heat extraction pipe for removing heat from the reactor, an internal filter for filtering out the catalyst in the heavy component products to be discharged from the reactor, a third-stage heat extraction pipe for removing heat from the reactor, and a top hydrocyclone for separating the catalyst entrained in the overhead gas leaving the tower top, which are arranged in sequence from bottom to top;

[0019] The bottom gas distributor is located at the lower head of the reactor cylinder body, and its air outlet openings face downward; the lower gas distributor is arranged in the lower part of the reactor, and its air outlet openings face downward.

[0020] To achieve another aspect of the above-mentioned invention object, the present invention adopts the following technical solutions:

[0021] A high-energy-efficiency Fischer-Tropsch synthesis system, the Fischer-Tropsch synthesis system includes the Fischer-Tropsch synthesis reactor as described above, and

[0022] a partition stripping column, the partition in the partition stripping column is vertically centeredly arranged from the tray in the middle of the partition stripping column to the bottom of the column, dividing the column body into three parts: a left lower column section, a right lower column section and an upper column section, wherein,

[0023] The lower part of the left lower column section is connected to the top outlet of the Fischer-Tropsch synthesis reactor through a pipeline to receive the light components as the overhead gas, and the upper part is connected to the heavy component outlet of the internal filter of the Fischer-Tropsch synthesis reactor through a pipeline to receive the heavy component products, for stripping the heavy component products with the overhead gas to discharge the separated heavy wax products from the bottom;

[0024] The right lower column section is provided with a supporting heavy oil reboiler, and the heavy oil reboiler is configured to heat a part of the heavy oil products from the bottom of the right lower column section by using the heavy component products discharged from the bottom of the left lower column section;

[0025] The upper column section is used to separate the light components and discharge them from the top, and the upper column section is also provided with a supporting reflux pipeline to reflux a part of the light oil condensed and separated from the light components;

[0026] A recycle gas heat exchanger is used to exchange heat and cool down the light components that have been cooled by the fresh gas heat exchanger with the recycle gas from the recycle gas pipe, and at least part of the heated recycle gas is sent to the inlet of the first inlet pipe, and the remaining part is sent to the inlet of the second inlet pipe;

[0027] A fresh gas heat exchanger is used to exchange heat and heat up the synthesis gas from the synthesis gas pipe with the light components from the partition stripping column, and the heated synthesis gas is sent to the inlet of the second inlet pipe;

[0028] An air cooler is used to cool the light components from the recycle gas heat exchanger;

[0029] A gas-liquid separator is used to separate the gas and liquid of the cooling product from the air cooler to separate the uncondensed tail gas, and part of the tail gas is sent to the first recycle gas compressor as the first recycle gas, and part of the tail gas is sent to the low-temperature oil washing unit;

[0030] An oil-water separation unit is used to separate the liquid phase from the gas-liquid separator to separate light oil from synthesis water, and part of the separated light oil is sent to the upper tower section as the top reflux, and part of the light oil is sent to the low-temperature oil washing unit;

[0031] A low-temperature oil washing unit is used to absorb and remove and recover the C components in the tail gas by using the light oil to obtain the oil-washed dry gas formed by the tail gas after removing the C components, the LPG product formed by the recovered C components, and the oil-washed naphtha formed after the desorption and regeneration of the light oil; 3 + components, obtaining the oil-washed dry gas formed by the tail gas after removing the C components, the LPG product formed by the recovered C components, and the oil-washed naphtha formed after the desorption and regeneration of the light oil; 3 + components, obtaining the oil-washed dry gas formed by the tail gas after removing the C components, the LPG product formed by the recovered C components, and the oil-washed naphtha formed after the desorption and regeneration of the light oil; 3 + components, obtaining the oil-washed dry gas formed by the tail gas after removing the C components, the LPG product formed by the recovered C components, and the oil-washed naphtha formed after the desorption and regeneration of the light oil;

[0032] A decarbonization unit is used to remove CO from the oil-washed dry gas from the low-temperature oil washing unit to obtain decarbonized purified gas, and part of the decarbonized purified gas is sent to the second recycle gas compressor as the second recycle gas, and part of the decarbonized purified gas is sent to the hydrogen recovery unit; 2 to obtain decarbonized purified gas, and part of the decarbonized purified gas is sent to the second recycle gas compressor as the second recycle gas, and part of the decarbonized purified gas is sent to the hydrogen recovery unit;

[0033] A hydrogen recovery unit is used to separate hydrogen from the decarbonized purified gas, and at least part of the separated hydrogen is mixed with the fresh synthesis gas from the outside and sent to the synthesis gas pipe as the synthesis gas;

[0034] One end of the circulation pipe is respectively connected to the compressed gas outlets of the first recycle gas compressor and the second recycle gas compressor to receive the mixed gas of the first recycle gas and the second recycle gas as the recycle gas, and the other end is connected to the recycle gas heat exchanger.

[0035] For another aspect of achieving the above-mentioned invention object, the present invention also provides a Fischer-Tropsch synthesis method, which uses the Fischer-Tropsch synthesis system as described above for Fischer-Tropsch synthesis.

[0036] Compared with the prior art, the present invention has the following advantages:

[0037] (1) In the present invention, recycle gas is introduced at the bottom of the reactor. By utilizing the relatively high catalyst concentration at the bottom of the reactor, the recycle gas is promoted to be effectively reconverted to improve the yield. At the same time, by using the relatively low effective gas concentration in the recycle gas, the runaway temperature at the bottom is avoided, thereby limiting the dilemma of further increasing the inlet gas volume to improve the production capacity, and improving the applicability of the reactor to highly active catalysts.

[0038] (2) In the present invention, fresh syngas is introduced downward from the lower gas distributor. On the one hand, it is beneficial for countercurrent contact with the upward flow from the bottom to improve the gas-liquid-solid three-phase mixing degree, thereby improving the conversion rate. On the other hand, by using the buffer of downward gas inlet, the collision and abrasion of the catalyst are reduced, enabling the heavy component products to enter the baffle stripping column for treatment, reducing the complexity of the original process and the redundant heating and cooling processes. The baffle stripping column can fully utilize the heat and pressure of the products, improving the energy efficiency and separation effect of the separation system; omitting the tail gas rough separation process in the traditional Fischer-Tropsch synthesis process flow, forming an oil product separation and recovery process flow with the tail gas-heavy wax baffle stripping column as the core, and cooperating with process optimizations such as adjusting the process sequence of tail gas decarbonization and low-temperature oil washing, which is beneficial to reducing energy consumption and improving the energy utilization efficiency of the process system.

[0039] (3) During tail gas treatment, a treatment process of first low-temperature oil washing and then decarbonization is adopted. After oil washing, MDEA can be used for tail gas decarbonization without fear of the loss of hydrocarbon products. Compared with the conventional hot potassium carbonate decarbonization technology, energy can be saved and the system energy efficiency can be improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1 It is a schematic structural diagram of an embodiment of the slurry bed Fischer-Tropsch synthesis reactor of the present invention;

[0041] Figure 2 It is a schematic diagram of an embodiment of the Fischer-Tropsch synthesis reaction system of the present invention;

[0042] Figure 3 It is the axial temperature distribution of the slurry bed reactor in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0043] To enable those skilled in the art to better understand the solution of the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative efforts shall fall within the scope of protection of the present invention.

[0044] It should be noted that the terms "first", "second", etc. in the description and claims of the present invention and the above-mentioned drawings are used to distinguish similar objects, and do not necessarily need to be used to describe a specific order or sequence. It should be understood that such data can be interchanged under appropriate circumstances so as to implement the embodiments of the present invention described herein. In addition, the terms "comprising" and "having" and any variations thereof are intended to cover non-exclusive inclusion. For example, a process, method, system, product or device comprising a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but may include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0045] As Figure 1 shown, the slurry bed Fischer-Tropsch synthesis reactor 1 of the present invention includes a reactor shell 101 and internal components disposed within the reactor shell 101; the internal components include a bottom gas distributor 103, a first-stage heat extraction tube 108 for removing heat from the reactor, a lower gas distributor 105, a second-stage heat extraction tube 109 for removing heat from the reactor, an internal filter 111 for filtering out the catalyst in the heavy component products to be discharged from the reactor, a third-stage heat extraction tube 110 for removing heat from the reactor, and a top hydrocyclone 107 for separating the catalyst entrained in the overhead gas leaving the tower, which are arranged in sequence from bottom to top.

[0046] As described above, the slurry bed Fischer-Tropsch synthesis reactor of the present invention is provided with three-stage heat extraction tubes, a first-stage internal filter, and a top hydrocyclone. These internal components are conventional in structure and arrangement and are well known in the art, and will not be elaborated here.

[0047] In the present invention, the bottom gas distributor 103 is located at the lower head of the reactor shell 101, and its air outlet openings face downward, and are used to receive at least part of the recycle gas; the lower gas distributor 105 is disposed in the lower part of the reactor, that is, below 1 / 3 of the reactor height, and its air outlet openings face downward, and are used to receive syngas and the remaining recycle gas. Those skilled in the art can understand that when all the recycle gas is introduced into the bottom gas distributor, the lower gas distributor will no longer receive the recycle gas.

[0048] In some embodiments, the bottom gas distributor 103 is located at the lower head of the reactor and is arranged against the bottom steel plate. The form of the distributor can be a bubble-cap gas distributor with the gas outlet openings facing downwards; the lower gas distributor 105 is an annular tube gas distributor with the gas outlet openings facing downwards. The sizes and numbers of the gas outlets of the two-stage distributors are designed according to actual conditions. In the present invention, the lower gas distributor 105 is arranged at the lower part of the reactor 1 to improve the synthesis conversion efficiency of the reactor 1. Preferably, the distance between the lower gas distributor 105 and the bottom gas distributor 103 is 1 / 10 - 1 / 6 of the height of the Fischer-Tropsch synthesis reactor 1 (in the present invention, the reactor height refers to the height inside the reactor during operation), such as 1 / 8.

[0049] In some embodiments, the internal component further includes a first inlet pipe 102 connected to the bottom gas distributor and a second inlet pipe 104 connected to the lower gas distributor, and the inlets of the first inlet pipe and the second inlet pipe are located between the third-stage heat extraction pipe 110 and the hydrocyclone separator 107; preferably, the outer walls of the first inlet pipe and the second inlet pipe are provided with threaded or fin structures to enhance heat transfer. Since the inlet pipeline is located inside the reactor, the threaded or fin structure is provided outside the pipeline to enhance heat transfer. The recycle gas and the incoming tower gas entering the reactor can directly and fully utilize the reaction heat for preheating, and the heat extraction system of the reactor can thus reduce the load, reduce the loss caused by heat recovery and reuse, and improve the system energy efficiency.

[0050] As Figure 2 shown, the Fischer-Tropsch synthesis system of the present invention includes the Fischer-Tropsch synthesis reactor 1 as described above, and a baffle stripper 4, a recycle gas heat exchanger 6, a fresh gas heat exchanger 5, an air cooler 7, a gas-liquid separator 8, an oil-water separation unit 10, a low-temperature oil washing unit 11, a decarbonization unit 12, and a hydrogen recovery unit 14.

[0051] Among them, the partition plate 41 in the partition rectifying column 4 is vertically centered from the tray in the middle of the partition rectifying column to the bottom of the column, dividing the column body into three parts: the left lower column section 42, the right lower column section 43, and the upper column section 44. Among them, the lower part of the left lower column section 42 is connected to the top outlet 106 of the Fischer-Tropsch synthesis reactor 1 through a pipeline to receive the light components as the tower outlet gas, and the upper part is connected to the heavy component outlet (i.e., the inner filter outlet) of the Fischer-Tropsch synthesis reactor 1 through a pipeline to receive the heavy component product, for stripping the heavy component product with the tower outlet gas to discharge the separated heavy wax from the bottom; the right lower column section 43 is equipped with a supporting heavy oil reboiler 16, and the heavy oil reboiler 16 is used to heat a part of the heavy oil product from the bottom of the right lower column section 43 with the heavy component product discharged from the bottom of the left lower column section 42; the upper column section 44 is used to separate the light components and discharge them from the top, and the upper column section 44 is also equipped with a supporting reflux pipeline to reflux a part of the light oil condensed and separated from the light components.

[0052] The circulating gas heat exchanger 6 is used to exchange heat and cool down the light components cooled by the fresh gas heat exchanger 5 with the circulating gas from the circulating gas pipe 19, and send at least part of the heated circulating gas to the air inlet of the first inlet pipe 102 and the remaining part to the air inlet of the second inlet pipe 104; for example, in the circulating gas, the proportion of the circulating gas entering the bottom gas distributor can be 40-100% such as 50%, 60%, 70%, 80% or 90%.

[0053] The fresh gas heat exchanger 5 is used to exchange heat and heat up the synthesis gas from the synthesis gas pipe 20 with the light components from the partition rectifying column 4, and send the heated synthesis gas to the air inlet of the second inlet pipe 104.

[0054] The air cooler 7 is used to cool the light components from the circulating gas heat exchanger 6.

[0055] The gas-liquid separator 8 is used to separate the gas and liquid of the cooling product from the air cooler to separate the uncondensed tail gas, and send part of the tail gas as the first circulating gas to the first circulating gas compressor 9 and part of the tail gas to the low-temperature oil washing unit 11; preferably, in the tail gas, the proportion of the tail gas as the first circulating gas is 70-90% such as 75%, 80% or 85%.

[0056] The oil-water separation unit 10 is used to separate the liquid phase from the gas-liquid separator 8 to separate the light oil from the synthesis water, and send part of the separated light oil as the top reflux to the upper column section 44 and part of the light oil to the low-temperature oil washing unit 11;

[0057] The low-temperature oil washing unit 11 is used to absorb with the light oil to remove and recover C in the tail gas3 + components to obtain the oil-washed dry gas formed by the tail gas after removing C 3 + components, the LPG product formed by the recovered C 3 + components, and the oil-washed naphtha formed after the desorption and regeneration of the light oil; In one embodiment, the low-temperature oil-washing unit 11 includes an absorption tower and a regeneration tower, wherein the absorption tower is used to absorb C3+ components in the tail gas with light oil to obtain absorption oil; The regeneration tower is used to desorb the absorption oil to desorb the absorbed C3+ components and send them out as LPG products, and obtain the regenerated oil-washed naphtha; In some embodiments, since the CO2 content of the treated tail gas is relatively high, 10%-20 vol%, such as 12 vol%, 15 vol% or 18 vol%, the operating temperature of low-temperature absorption is preferably set at 10-20 °C, such as 12, 15 or 18 °C, so as to reduce the absorption of light oil on CO 2 under the influence of concentration and ensure that the purity of the LPG product is greater than 95 mol%. 2 components, ensuring that the purity of the LPG product is greater than 95 mol%.

[0058] The decarbonization unit 12 is used to remove CO 2 from the oil-washed dry gas from the low-temperature oil-washing unit 11 to obtain decarbonized purified gas, and send part of the decarbonized purified gas as the second recycle gas to the second recycle gas compressor 13 and part of the decarbonized purified gas to the hydrogen recovery unit 14; Preferably, in the oil-washed dry gas, the proportion of the oil-washed dry gas as the second recycle gas is 30%-60%, such as 40% or 50%. In the present invention, since the low-carbon hydrocarbons in the gas have been recovered by the low-temperature oil-washing unit in advance, the decarbonization unit is preferably a MEDA decarbonization unit using MEDA decarbonization technology.

[0059] The hydrogen recovery unit 14 is used to separate hydrogen from the decarbonized purified gas, and mix at least part of the separated hydrogen with fresh syngas from the outside and send it as syngas to the syngas pipe 20.

[0060] One end of the circulation gas pipe 9 is respectively connected to the compressed gas outlets of the first circulation gas compressor 9 and the second circulation gas compressor 13 to receive the mixed gas of the first circulation gas and the second circulation gas as the circulation gas, and the other end is connected to the circulation gas heat exchanger 6.

[0061] In some embodiments, the Fischer-Tropsch synthesis system further includes a wax filtration unit 17, a synthesis water treatment unit 15, and an oil product treatment unit 18; wherein, the wax filtration unit is configured to filter the heavy wax from the heavy oil reboiler to remove solid impurities, such as crushed catalysts; the synthesis water treatment unit is configured to treat the synthesis water from the oil-water separation unit to recover alcohol organic substances, and the remaining aqueous phase is discharged as wastewater after treatment; the oil product treatment unit is used to treat light oil, heavy oil, and the heavy wax filtered by the wax filtration unit, and products such as naphtha, diesel, and wax are obtained through processes such as hydrorefining and hydroisomerization respectively.

[0062] When the Fischer-Tropsch synthesis system of the present invention operates, part of the recycle gas enters the first inlet pipe 102 after passing through the recycle gas heat exchanger 6, and the synthesis gas (fresh purified synthesis gas + recycle hydrogen) is mixed with part of the heat-exchanged recycle gas and enters the second inlet pipe 104 after passing through the fresh gas heat exchanger 5; wherein, the hydrogen-carbon ratio of the synthesis gas can be 2-4:1, such as 2.5:1, 3:1, or 3.5:1.

[0063] The slurry bed Fischer-Tropsch synthesis reactor of the present invention is provided with two-stage gas distributors, and the gas with a higher effective gas content is introduced into the lower gas distributor 105. Preferably, the average residence time of the gas at the outlet of the lower gas distributor is greater than 120 s, preferably 120 s - 160 s, such as 130 s, 140 s, or 150 s.

[0064] The gas passes through the slurry bed reactor 1 and undergoes Fischer-Tropsch synthesis reaction and water-gas shift reaction under the action of the catalyst; preferably, the control parameters of the slurry bed Fischer-Tropsch synthesis reactor 1 are: temperature 255 - 280 °C, such as 255 - 275 °C, 260 - 280 °C, pressure 2 - 4 MPa, such as 2.5, 3, or 3.5 MPa, the apparent gas velocity at the outlet of the bottom gas distributor is 0.18 - 0.3 m / s, such as 0.2, 0.24, or 0.26 m / s, the apparent gas velocity at the outlet of the lower gas distributor is 0.1 - 0.3 m / s, such as 0.15, 0.2, or 0.25 m / s, and the superposed apparent gas velocity above the lower gas distributor is 0.3 - 0.6 m / s, such as 0.35, 0.4, 0.45, 0.5, or 0.55 m / s; in the present invention, the catalyst can be a Fischer-Tropsch synthesis iron-based catalyst, such as the CNFT-1 catalyst, and its concentration in the slurry can be 8 - 30 wt%, such as 10 wt% or 20 wt%, preferably 15 - 25 wt%.

[0065] The heavy component products in the reactor are discharged from the reactor after being filtered by the internal filter 110, and the light component products and unreacted gases in the reactor are discharged from the top outlet 106 of the reactor in the vapor phase. The outlet gas from the tower and the heavy component products directly enter the baffle stripper 4.

[0066] The partition stripper 4 is a distillation column with complete thermal coupling characteristics. Its partition 41 is arranged in the middle and lower part of the distillation column, vertically centered from the middle tray to the bottom of the column, dividing the column section into three parts. The lower left column section 42 strips the heavy component products with the outlet gas to separate heavy wax. The lower right column section 43 of the column uses the heat of the heavy wax in the lower left column section to form a reboiler to separate intermediate components (heavy oil). The upper column section 44 is used to separate light components (light oil, water, tail gas), and partial reflux of light oil is set. Of course, multiple sets of side line products can also be set in the lower right column section 43 of the partition stripper 4 according to the fraction requirements of the product. Preferably, the operating pressure of the partition stripper 4 is 0.5 - 1 MPa lower than the pressure of the Fischer - Tropsch synthesis reactor 1, such as 0.6 or 0.8 MPa.

[0067] The bottom stream of the lower left column section flows out, exchanges heat through the heavy oil heat exchange reboiler 16, then enters the wax filtration unit 17 for filtration, and then enters the oil processing unit 18. Part of the bottom product of the lower right column section 43 exchanges heat through the heavy oil heat exchange reboiler 16 and then returns to the bottom of the lower right column section of the partition stripper, and part enters the oil processing unit 18.

[0068] The light components of the upper column section 44 leave the column in the vapor phase. First, they exchange heat and cool down with the syngas through the fresh gas heat exchanger 5, then exchange heat and cool down with the recycle gas through the recycle gas heat exchanger 6, and then enter the air cooler 7 for further cooling, preferably cooled to 20 - 50 °C, such as 30 or 40 °C. The cooled gas - liquid mixture enters the gas - liquid separator 8. Preferably, the operating temperature of the gas - liquid separator is at room temperature, and the pressure is 0.1 - 0.5 MPa lower than that of the partition stripper 4, such as 0.2, 0.3 or 0.4 MPa.

[0069] The liquid separation product of the gas - liquid separator 8 enters the oil - water separator 10 to separate light oil and synthesis water. The operating conditions are preferably at room temperature and normal pressure. Part of the gas separation product enters the first recycle gas compressor 9 to be pressurized to be, for example, 0.2 - 0.5 MPa higher than that of the slurry bed reactor 1, such as 0.3 or 0.4 MPa, and part enters the low - temperature oil washing unit 11.

[0070] The synthesis water separated by the oil - water separator 10 enters the synthesis water treatment unit 15 to recover oxygen - containing compounds such as mixed alcohols, and the remaining water phase is discharged as wastewater after treatment. Part of the separated light oil is refluxed to the top of the partition stripper 4, and part enters the low - temperature oil washing unit 11 as a solvent.

[0071] The tail gas and light oil enter the low - temperature oil washing unit 11 to recover the C 3 + components in the tail gas to form oil - washed naphtha and LPG products. The oil - washed naphtha enters the oil processing unit 18, and the oil - washed dry gas enters the MEDA decarbonization unit 12 to remove CO 2Part of the decarbonized purified gas after that enters the second recycle gas compressor 13 and is pressurized to, for example, 0.2 - 0.5 MPa higher than that of the slurry bed reactor 1, such as 0.3 or 0.4 MPa, and then converges with the first recycle gas, and part of it enters the hydrogen recovery unit 14.

[0072] Part of the hydrogen in the hydrogen recovery unit 14 enters the oil processing unit 18, and part of it is used as recycle hydrogen and converges with the fresh purified gas; after the first recycle gas converges with the decarbonized purified gas as the second recycle gas and exchanges heat through the recycle gas heat exchanger 6, at least part of it enters the first inlet pipe, and the remaining part is mixed with the syngas heated by the fresh gas heat exchanger 5 and enters the second inlet pipe 104, and the proportion of the recycle gas entering the bottom gas distributor 103 and the lower gas distributor 105 can be adjusted by using equipment such as valves and flow meters according to the actual reaction conditions. For example, on the premise that the apparent gas velocity parameter meets the control requirements, when the temperature near the bottom gas distributor of the reactor exceeds the set temperature by 2 °C, the proportion of the recycle gas entering the bottom gas distributor should be reduced in a timely manner, and vice versa, the proportion of the recycle gas entering the bottom gas distributor can be increased, and the specific adjustment range can be gradually set according to the actual situation.

[0073] Through the optimized design of the Fischer - Tropsch synthesis slurry bed reactor of the present invention, there are fewer catalyst fines in the outlet gas of the tower. Therefore, the rough separation process before the stripping column in the current industrial process can be omitted, and the heavy - component product and the outlet gas are directly introduced into the dividing wall stripping column with complete thermal coupling characteristics for fine separation, reducing the complexity of the process and reducing the cooling and re - heating steps in the process. The dividing wall stripping column realizes the effect of double - tower separation in one tower, can make full use of the heat of the product, and at the same time improve the concentration degree of the carbon number distribution of each component. The above - mentioned processes can effectively reduce equipment investment and save energy and reduce consumption;

[0074] In the process system supporting the slurry bed Fischer - Tropsch synthesis reactor of the present invention, low - temperature oil washing operation is preferentially carried out in the tail gas treatment to recover C3+ hydrocarbon components, and the CO in the tail gas 2 will not limit the operation of the low - temperature oil washing unit, so that the LPG recovery of the gas with a relatively high CO content can be realized by adjusting the reflux ratio of the absorption tower and the regeneration tower. After the tail gas passes through the low - temperature oil washing, it enters the decarbonization unit (the recycled tail gas is adjusted to recycle and enter the CO of the gas entering the Fischer - Tropsch synthesis reactor 2 composition), and the MDEA absorption technology can be adopted. Compared with the hot potassium carbonate technology of the current industrial process, it can significantly reduce energy consumption. 2 The following further illustrates the present invention with reference to the embodiments.

[0075] Embodiment 1

[0076] Example 1

[0077] Industrial-scale Fischer-Tropsch synthesis slurry bed reactor and supporting process system. The inner diameter of the slurry bed reactor is 9.6 m, the liquid level height of the reactor is 50 m, the gas distributor at the bottom of the reactor and the lower gas distributor are arranged at an interval of 6 m, and the inlet pipeline passes through the inside of the reactor, and the height of the inlet pipe orifice is 55 m. The fresh purified syngas inlet is 440 kNm 3 / h, the loaded catalyst is an iron-based catalyst (CNFT-1 catalyst independently developed by the National Energy Group, the same below), the particle size distribution is 30 - 120 μm, the average particle size is 75 μm, the abrasion is less than 5%, the catalyst loading is 90 t, the reactor control temperature is 272 °C, and the top pressure is 3.5 MPa.

[0078] The number of plates of the dividing wall stripper is 40, the feed position of the outlet gas is at the left bottom of the tower, the feed position of the heavy wax is at the 35th plate, the operating pressure is 3 MPa, the left bottom of the tower is 250 °C, the right bottom of the tower is 160 °C, the top of the tower is 80 °C, the operating temperature of the air cooler is 40 °C, the operating conditions of the oil-water separator are normal temperature and pressure, the circulating gas compressor boosts the pressure to 3.8 MPa, the main circulating gas flow rate is ~990 kNm 3 / h, the oil-washed dry gas is ~190 kNm 3 / h, the decarbonized purified gas flow rate is ~110 kNm 3 / h, the total circulating gas flow rate is ~1100 kNm 3 / h, the total inlet gas flow rate is ~1540 kNm 3 / h, the circulating gas flow rate controlled at the bottom gas distributor is ~300 kNm 3 / h, the mixed gas flow rate at the lower gas distributor is ~1240 kNm 3 / h, the superficial gas velocity of the total gas in the reactor is 0.34 m / s. The composition of various gases in the process flow is shown in Table 1, and the axial temperature distribution in the reactor under this condition is as Figure 3 shown, the axial temperature difference is less than 2 °C, and there is no situation where the temperature soars due to intense reaction at the bottom of the reactor. The performance indicators of the device operation under this working condition are shown in Table 2, the oil production capacity reaches 79.28 t / h, and compared with the normal situation of industrial operation, it is increased by about 27%. The energy consumption and output are shown in Table 3, and the energy conversion efficiency of the oil synthesis system is 75.31%, and compared with the normal situation of industrial operation, it is increased by about 5%.

[0079] Table 1 Composition of main gas streams

[0080]

[0081]

[0082] Table 2 Device operation performance

[0083] Operating index Value CO conversion rate, % 97.74 <![CDATA[CO 2 Selectivity, mol%]]> 17.83 <![CDATA[CH 4 Selectivity, mol%]]> 2.22 <![CDATA[C 3 + Selectivity, mol%]]> 78.40 <![CDATA[C 3 + Output, t / h]]> 79.28 <![CDATA[Ton oil and gas consumption, Nm 3 / h / tC 3 + > 5488 <![CDATA[Spatial-time yield, tC 3 + / h / tcat]]> 0.881

[0084] Table 3 Energy Efficiency of Device Operation

[0085]

[0086]

[0087] Comparative Example 1

[0088] The difference from Example 1 is that: the reactor has only one set of air inlets at the bottom gas distributor, and the outlet gas at the top of the reactor first undergoes a rough separation process of two-stage cooling and two-stage separation, and then enters a conventional stripper. The rough-separated Fischer-Tropsch synthesis tail gas first undergoes decarbonization treatment and then low-temperature oil washing treatment, and the rest are the same.

[0089] During operation, it was found that when the fresh gas inlet flow rate reached 360 Nm 3 / h, the temperature at the bottom of the reactor exceeded 277 °C, and the temperature difference between the bottom and the middle of the reactor exceeded 4 °C. The deactivation rate of the catalyst accelerated at this temperature, the activity decreased, and the fresh gas treatment capacity could not be further increased, limiting the further improvement of the reactor production capacity. The maximum reactor production capacity could only reach about 65 t / h. At this production capacity, the energy consumption of the overall Fischer-Tropsch synthesis process system was higher, and the energy conversion efficiency was about 70%.

[0090] Comparative Example 2

[0091] The difference from Example 1 is that: the outlet of the lower gas distributor is set upward, and the rest are the same as Example 1.

[0092] During operation, the CO conversion rate decreased to about 96.5%, and the C3+ production capacity decreased to about 76 t / h. And because there was more catalyst pulverization, it would cause an increase in catalyst fines in the upper slurry of the reactor. In the case of insufficient catalyst unloading, the catalyst fines were entrained into the baffle stripper with the tail gas and entered the heavy wax product, increasing the fine filtration cost of the stable wax product; the catalyst fines and droplets entrained with the gas mixed and entered the heat exchanger, and long-term deposition would cause blockage of the heat exchanger.

[0093] Comparative Example 3

[0094] The difference from Example 1 is that: the air inlets of the bottom gas distributor and the lower gas distributor are swapped, and the rest are the same as Example 1.

[0095] During operation, due to the relatively high effective gas concentration at the bottom of the reactor and the relatively low H 2 / CO in the gas composition, a problem similar to that in Comparative Example 1 occurred. The temperature at the bottom of the reactor was relatively high, but the temperature in the middle was relatively low, and the temperature difference of the reactor was relatively large. When the fresh gas inlet volume reached 350 kNm 3After / h, the bottom temperature exceeds 277°C, and it is impossible to further increase the fresh gas treatment capacity, and the reactor cannot reach the target production capacity.

Claims

1. A high-capacity slurry-phase Fischer-Tropsch synthesis reactor, comprising a reactor shell and internal components disposed within the reactor shell; Characterized in that: The internal components include a bottom gas distributor, a first-stage heat extraction pipe for removing heat from the reactor, a lower gas distributor, a second-stage heat extraction pipe for removing heat from the reactor, an internal filter for filtering the catalyst from the heavy-component products to be discharged from the reactor, a third-stage heat extraction pipe for removing heat from the reactor, and a top hydrocyclone for separating the catalyst entrained in the overhead gas leaving the top of the column, which are arranged in sequence from bottom to top; The bottom gas distributor is located at the lower head of the reactor shell, and its gas outlet openings face downward; the lower gas distributor is disposed in the lower part of the reactor, and its gas outlet openings face downward.

2. The slurry-phase reactor according to claim 1, Characterized in that, The internal components further include a first inlet pipe connected to the bottom gas distributor and a second inlet pipe connected to the lower gas distributor, and the inlets of the first inlet pipe and the second inlet pipe are located between the third-stage heat extraction pipe and the hydrocyclone; preferably, the outer walls of the first inlet pipe and the second inlet pipe are provided with threads or fin structures to enhance heat transfer.

3. The slurry-phase reactor according to claim 1 or 2, Characterized in that, The distance between the lower gas distributor and the bottom gas distributor is 1 / 10 - 1 / 6 of the height of the reactor, wherein the bottom gas distributor is a bubble-cap gas distributor and the lower gas distributor is an annular-pipe gas distributor.

4. A high-energy-efficiency Fischer-Tropsch synthesis system, Characterized in that, The Fischer-Tropsch synthesis system includes the Fischer-Tropsch synthesis reactor according to any one of claims 1 - 3, and A partition stripping column, wherein the partition within the partition stripping column is vertically centeredly arranged from the tray in the middle of the partition stripping column to the bottom of the column, dividing the column body into three parts: a left lower column section, a right lower column section, and an upper column section. Among them, The lower part of the left lower column section is connected to the top outlet of the Fischer-Tropsch synthesis reactor through a pipeline to receive the light components as the overhead gas, and the upper part is connected to the heavy-component outlet of the internal filter of the Fischer-Tropsch synthesis reactor through a pipeline to receive the heavy-component products, for stripping the heavy-component products with the overhead gas to discharge the separated heavy wax products from the bottom; The right lower column section is provided with a supporting heavy oil reboiler, and the heavy oil reboiler is configured to heat a part of the heavy oil products from the bottom of the right lower column section by using the heavy-component products discharged from the bottom of the left lower column section; The upper column section is used for separating the light components and discharging them from the top, and the upper column section is further provided with a supporting reflux pipeline to reflux a part of the light oil condensed and separated from the light components; A recycle gas heat exchanger, configured to exchange heat and cool the light components cooled by the fresh gas heat exchanger with the recycle gas from the recycle gas pipeline, and send at least part of the heated recycle gas to the inlet of the first inlet pipe and the remaining part to the inlet of the second inlet pipe; Fresh gas heat exchanger, which is used to heat up the synthesis gas from the synthesis gas pipe by heat exchange with the light components from the dividing plate stripping column, and send the heated synthesis gas into the air inlet of the second inlet pipe; Air cooler, which is used to cool the light components from the circulating gas heat exchanger; Gas-liquid separator, which is used to carry out gas-liquid separation on the cooling product from the air cooler to separate the uncondensed tail gas, and send part of the tail gas into the first circulating gas compressor as the first circulating gas and part of the tail gas into the low-temperature oil washing unit; Oil-water separation unit, which is used to separate the liquid phase from the gas-liquid separator to separate light oil from synthesis water, and send part of the separated light oil into the upper tower section as the top reflux and part of the light oil into the low-temperature oil washing unit; Low-temperature oil washing unit, used to remove and recover C in the tail gas by absorbing with the light oil 3 + components, obtaining the oil washing dry gas formed by the tail gas after removing C 3 + components, the LPG product formed by the recovered C 3 + components and the oil washing naphtha formed after the light oil is desorbed and regenerated; A decarbonization unit for removing CO from the washed dry gas of the low-temperature oil washing unit 2 , obtaining decarbonized purified gas, and sending part of the decarbonized purified gas as the second recycle gas to the second recycle gas compressor and part of the decarbonized purified gas to the hydrogen recovery unit; Hydrogen recovery unit, which is used to separate hydrogen from the decarbonized purified gas, and mix at least part of the separated hydrogen with the fresh synthesis gas from the outside and send it into the synthesis gas pipe as the synthesis gas; One end of the circulation pipe is respectively connected to the compressed gas outlets of the first circulating gas compressor and the second circulating gas compressor to receive the mixed gas of the first circulating gas and the second circulating gas as the circulating gas, and the other end is connected to the circulating gas heat exchanger.

5. The Fischer-Tropsch synthesis system according to claim 3, characterized in that, The low-temperature oil washing unit includes an absorption tower and a regeneration tower, wherein the absorption tower is used to absorb C components in the tail gas with light oil to obtain absorption oil; the regeneration tower is used to desorb the absorption oil to desorb the absorbed C3+ components and send them out as LPG products, and obtain regenerated oil-washing naphtha. 3 + ​ 6. A Fischer-Tropsch synthesis method, characterized in that, The Fischer-Tropsch synthesis is carried out by using the Fischer-Tropsch synthesis system according to claim 4 or 5.

7. The Fischer-Tropsch synthesis method according to claim 6, characterized in that, The control parameters of the slurry bed reactor are: temperature 255 - 280 °C, pressure 2 - 4 MPa, the superficial gas velocity at the outlet of the bottom gas distributor is 0.18 - 0.3 m / s, the superficial gas velocity at the outlet of the lower gas distributor is 0.1 - 0.3 m / s, and the superimposed superficial gas velocity above the lower gas distributor is 0.3 - 0.6 m / s; And, the average residence time of the outlet gas of the lower gas distributor is greater than 120 s, preferably 120 - 160 s.

8. The Fischer-Tropsch synthesis method according to claim 6 or 7, characterized in that, The heavy component product obtained by the reaction is discharged from the Fischer-Tropsch synthesis reactor through internal filtration, and the off-gas from the tower is discharged from the top of the reactor. The off-gas from the tower and the heavy component product directly enter the dividing plate stripping column; the operating pressure of the dividing plate stripping column is 0.5 - 1 MPa lower than the pressure of the slurry bed reactor; The light components in the upper part of the slurry bed reactor leave the tower in gaseous form, first pass through the fresh gas heat exchanger to exchange heat and cool down with the synthesis gas, then pass through the circulating gas heat exchanger to exchange heat and cool down with the circulating gas, and then enter the air cooler to be further cooled to 20 - 50 °C. The cooled gas-liquid mixture enters the gas-liquid separator; the gas-liquid separator is at normal temperature, and the pressure is 0.1 - 0.5 MPa lower than that of the dividing plate stripping column; The liquid separation product of the gas-liquid separator enters the oil-water separator at normal temperature and normal pressure to separate light oil and synthesis water, and the gas separation product enters the first circulating gas compressor as part of the tail gas to be pressurized to 0.2 - 0.5 MPa higher than the slurry bed reactor, and part enters the low-temperature oil washing unit. In the low-temperature oil washing unit, the light oil is used to absorb the C components in the tail gas, the absorption temperature is 10-20 °C, the treated oil-washed dry gas enters the decarbonization unit, and the decarbonization unit is a MEDA decarbonization unit. 3 + ​ 9. The Fischer-Tropsch synthesis method according to any one of claims 6-8, characterized in that, in the tail gas, the proportion of the tail gas as the first recycle gas is 70-90%; in the oil-washed dry gas, the proportion of the oil-washed dry gas as the second recycle gas is 30-60%; in the recycle gas, the proportion of the recycle gas entering the bottom gas distributor is 40-100%.

10. The Fischer-Tropsch synthesis method according to any one of claims 6-9, characterized in that, when carrying out Fischer-Tropsch synthesis, the catalyst used is a Fischer-Tropsch synthesis iron-based catalyst, and its concentration is 8-30 wt%.

Images