CN117771830A

CN117771830A - System and method for Fischer-Tropsch product pre-separation

Info

Publication number: CN117771830A
Application number: CN202211152004.2A
Authority: CN
Inventors: 张琪; 王涛; 张雪冰; 孟祥堃; 程萌; 冯留海; 门卓武; 吕毅军
Original assignee: China Energy Investment Corp Ltd; National Institute of Clean and Low Carbon Energy
Current assignee: China Energy Investment Corp Ltd; National Institute of Clean and Low Carbon Energy
Priority date: 2022-09-21
Filing date: 2022-09-21
Publication date: 2024-03-29

Abstract

The invention provides a system and a method for pre-separating a Fischer-Tropsch product, wherein the system comprises a gas-liquid phase separation unit, a gas-phase refining unit and a water-oil phase separation unit; the gas-liquid phase separation unit comprises a gas-liquid phase separation tank, and a gas-liquid flow director and a baffle plate assembly are coaxially arranged in the gas-liquid phase separation tank in sequence from bottom to top; the gas-liquid flow director comprises a cylindrical main body, a feeding hole is arranged on the bottom surface of the main body, and at least the lower part of the cylinder wall is in a grid structure; the baffle plate assembly comprises a fixed shaft and a baffle plate which are coaxially arranged with the cylindrical main body; the gas phase refining unit comprises a cyclone separator and is connected to a gas phase outlet of the gas-liquid phase separation tank; the water-oil phase unit comprises a water-oil phase box which is respectively connected to the liquid phase outlets of the gas-liquid phase separation unit and the gas-phase refining unit. Methods of using the system are also provided. The system and the method can be used for the Fischer-Tropsch product pre-separation, can reduce the mutual entrainment of gas and liquid phases in the Fischer-Tropsch product pre-separation process, and improve the multiphase separation efficiency and the purity of the separated products.

Description

System and method for Fischer-Tropsch product pre-separation

Technical Field

The invention belongs to the field of material separation, and particularly relates to a system and a method for pre-separating a Fischer-Tropsch product.

Background

Fischer-Tropsch synthesis is the synthesis of gas (CO and H ₂ ) The conversion to hydrocarbon organics (mainly including alkanes, alkenes, etc.) by specific catalysts is accompanied by the formation of large amounts of water and portions of oxygen-containing organics (mainly alcohols, aldehydes, acids, etc.) in the process, with concomitant release of large amounts of heat.

In the fischer-tropsch synthesis project that has been started up at present, the primary separation of water and hydrocarbon products produced by most fischer-tropsch synthesis reactions involves: the product is cooled and flashed, most of water and oil are cooled into liquid phase fluid, and water phase fluid (namely Fischer-Tropsch synthesis water) containing a small amount of hydrocarbon, oxygen-containing organic matters and trace suspended matters is separated from the liquid phase fluid through an oil-water separator; because of the existence of hydrocarbon and oxygen-containing organic matters, fischer-Tropsch synthesis water cannot be directly discharged, for example, the water and the oxygen-containing organic compounds are separated and recycled, so that the technical economy in the Fischer-Tropsch synthesis process can be effectively improved, fischer-Tropsch synthesis products are enriched, the environmental-friendly treatment load of an aqueous phase is reduced, the recycling of the water is realized, and the clean production in the coal-to-oil process can be realized.

In the actual production process, because the effect difference of the oil-water separation process is large, light oil and a small amount of suspended matters are entrained in the separated Fischer-Tropsch synthesis water, so that the running stability of a downstream synthesis water treatment unit is poor, the Fischer-Tropsch synthesis water treatment effect is influenced, and the stable running of the whole factory is further influenced; therefore, pretreatment before Fischer-Tropsch synthesis water enters a downstream synthesis water treatment unit is particularly important for ensuring stable operation of the whole water treatment unit, and separation of light oil, suspended matters and the like entrained in the Fischer-Tropsch synthesis water can be realized by carrying out pretreatment.

CN113135611a discloses an oil-water separation pretreatment device for fischer-tropsch synthesis water, an apparatus comprising the same and a treatment method, wherein a specific filter element is arranged in the oil-water separation pretreatment device, and heavy oil and a small amount of suspended matters entrained in the fischer-tropsch synthesis water are simply and effectively separated from water by utilizing the water-oil density difference through the interception effect of the filter element. And back blowing is carried out on the filter element of the oil-water separation pretreatment device according to the filter pressure difference or the running time of the device so as to ensure the interception effect of the filter element on oil and suspended matters. The core comprises: a coalescing element for coalescing oil, a vertically disposed U-shaped filter; the filter element is prepared from one or more selected from organic polymer materials, wire mesh and/or sintered metal powder, including filter bags, ceramic filters, wire mesh filters, candle type and/or sintered metal powder filters; the organic polymer material comprises polyethylene, polypropylene, polyvinyl chloride, polyester and/or polytetrafluoroethylene.

But it is still difficult to fully solve the following problems: the actual separation effect of the Fischer-Tropsch synthesis water phase and the oil phase is greatly influenced by the catalyst and the process, and the emulsification and mutual entrainment of water and oil are serious; the low carbon number and volatile components are entrained by gas phase to cause product loss; the gas phase separation effect is insufficient, so that heavy components are easy to be entrained to the subsequent flow, and a pipeline is blocked; the separation efficiency of the liquid phase product is low, so that the downstream process is more complex, and the purity of the product is low; light oil and a small amount of suspended matters are entrained in the separated Fischer-Tropsch synthesis water, so that the stable operation of a downstream synthesis water treatment unit is affected.

Therefore, the effect of the prior pre-separation system and method for the Fischer-Tropsch products needs to be improved, and a more efficient method is needed to realize the effective separation of water, oil and gas of the Fischer-Tropsch products.

Disclosure of Invention

The first object of the invention is to provide a system for pre-separating Fischer-Tropsch products, which can be used for pre-separating Fischer-Tropsch products, can effectively reduce the mutual entrainment of gas phase and liquid phase, and improves the pre-separating effect on the Fischer-Tropsch products.

The second object of the invention is to provide a method for pre-separating Fischer-Tropsch products by using the system, which can pre-separate Fischer-Tropsch products, effectively reduce mutual entrainment of gas phase and liquid phase and improve the pre-separation effect of Fischer-Tropsch products.

To achieve the first object of the present invention, there is provided a system for pre-separation of a fischer-tropsch product, the system comprising a gas-liquid phase separation unit, a gas-phase refining unit and a water-oil phase separation unit; wherein,

the gas-liquid phase separation unit comprises a gas-liquid phase separation tank, is used for feeding a Fischer-Tropsch product, carrying out gas-liquid separation on the Fischer-Tropsch product, outputting a gas phase from the top of the Fischer-Tropsch product to the gas phase refining unit, and outputting a liquid phase from the bottom of the Fischer-Tropsch product to the water-oil phase separation unit;

the gas-liquid split-phase tank is internally and sequentially coaxially provided with a gas-liquid deflector and a baffle plate assembly from bottom to top;

The gas-liquid deflector comprises a cylindrical body; a feeding port is arranged on the bottom surface of the cylindrical main body and is used for feeding Fischer-Tropsch products; at least the lower part of the cylinder wall of the cylindrical main body is of a grid structure and is used for carrying out gas-liquid separation on Fischer-Tropsch products entering the cylindrical main body and guiding and outputting separated liquid phase from the grid structure to the gas-liquid phase separation tank;

the baffle plate assembly comprises a fixed shaft and a baffle plate which are coaxially arranged with the cylindrical main body and is used for carrying out liquid interception on partial gas phase separated from Fischer-Tropsch products entering the gas-liquid deflector;

the gas phase refining unit comprises a cyclone separator, wherein the cyclone separator is connected to a gas phase outlet of the gas-liquid phase separation tank in the gas-liquid phase separation unit and is used for receiving the gas phase from the gas-liquid phase separation unit and performing cyclone separation on the gas phase, outputting the gas phase from the top of the gas phase and outputting the liquid phase from the bottom of the gas phase;

the water-oil separation unit comprises a water-oil separation box which is respectively connected to the liquid phase outlet of the gas-liquid separation unit and the liquid phase outlet of the gas-phase refining unit and is used for receiving the liquid phase from the gas-liquid separation unit and the liquid phase from the gas-phase refining unit and separating water from oil.

Preferably, in the gas-liquid phase separation unit, the top surface of the cylindrical main body is provided with a plurality of first air holes, and the first air holes are distributed on the top surface of the cylindrical main body and are used for carrying out diversion output and liquid interception on part of gas separated from the fed fischer-tropsch product; and/or

In the baffle plate assembly, the baffle plate has n layers, and n is more than or equal to 1; the single-layer baffle plates from bottom to top are sequentially and coaxially fixed on the fixed shaft at intervals, and a first gap is reserved between the baffle plates and the inner wall of the gas-liquid phase separation tank and is used as a gas channel; the double-layer baffle plates from bottom to top are sequentially and coaxially fixed on the inner wall of the gas-liquid phase separation tank at intervals, and a second gap is reserved between the baffle plates and the fixed shaft and is used as a gas channel;

preferably, the baffle is of conical structure; preferably the cone angle of the baffles is 60-120 °;

preferably, the plate surface of the baffle plate is provided with a plurality of second air holes which are distributed on the plate surface of the baffle plate; preferably, the diameter of the second air hole is 1-3mm;

preferably, on the baffle plate, the total area of the second air holes accounts for 0-20%;

Preferably, the plate surface of the baffle plate is also provided with a liquid guide groove, and the head end of the liquid guide groove is positioned on the plate surface of the baffle plate, and the tail end of the liquid guide groove is positioned at the edge of the baffle plate and used for guiding liquid drops condensed on the baffle plate to the bottom of the gas-liquid phase separation tank;

preferably, the width of the liquid guide groove is 2-5mm; preferably, the depth of the liquid guide groove is 1-5mm;

preferably, the liquid guide groove comprises a first liquid guide groove, and the first liquid guide groove is arranged from the center to the edge of the baffle plate; and/or

The liquid guide groove comprises a second liquid guide groove, and the head end of the second liquid guide groove is positioned at 1/3-2/3 of the position from the center to the edge of the baffle plate.

Preferably, the height-to-diameter ratio of the gas-liquid phase separation tank is (1.5-4): 1; and/or

The height ratio of the gas-liquid phase separation tank to the gas-liquid flow guider is (1.5-3) 1; and/or

The diameter ratio of the gas-liquid phase separation tank to the gas-liquid flow guider is (1.5-5): 1.

Preferably, a water-oil separation chamber is arranged in the water-oil separation chamber, and the bottom surface of the water-oil separation chamber is sequentially lowered along the direction from the feeding end wall to the opposite end wall of the water-oil separation chamber; the feed inlet of the water-oil separation chamber is connected to the liquid phase outlet of the gas-liquid phase separation unit and the liquid phase outlet of the gas-phase refining unit and is used for feeding the liquid phase from the gas-liquid phase separation unit and the liquid phase from the gas-phase refining unit;

An m-level water-oil separation unit is arranged in the water-oil separation chamber, and m is more than or equal to 1, and is used for sequentially removing oil phases in the liquid phase from a feeding end to an opposite end; the water-oil separation unit comprises a coalescing oil absorption component, an oil collection component and an oil transportation component; in the m-level water-oil separation unit,

the coalescing oil absorption assembly is vertically arranged in the water-oil separation chamber, and is sequentially arranged at intervals from a feeding end to an opposite end in the water-oil separation chamber to divide the water-oil separation chamber into m water-oil separation sub-chambers and water chambers which are sequentially arranged from the feeding end to the opposite end;

the oil conveying component is horizontally arranged at the upper part of the water-oil separation chamber and is used for outputting oil phase from the oil collecting component;

the oil collecting assembly is suspended below the oil conveying assembly and is in flexible connection with the oil conveying assembly, and is used for floating on the surface of the feeding liquid phase;

the coalescing oil absorption component is used for outputting a water phase after intercepting residual oil phase in the liquid phase after oil is collected by the oil collection component;

the water chamber is used for receiving the water phase output by the m-level water-oil separation unit;

preferably, the oil collecting assembly comprises a first oil collecting assembly in the horizontal direction and a second oil collecting assembly in the vertical direction, the first oil collecting assembly is horizontally floated on the surface of the feed liquid phase, and two ends of the second oil collecting assembly are respectively connected to the first oil collecting assembly and the oil conveying assembly and are used for sequentially collecting the oil phase in the feed liquid phase.

Preferably, the bottom surface of the water-oil separation chamber is arranged in a stepwise decreasing manner in sequence along the direction from the feeding end wall of the water-oil separation chamber to the opposite end wall thereof;

preferably, the bottom surfaces of the m water-oil separation sub-chambers and the water chamber are arranged in a stepwise decreasing manner in sequence along the direction from the feeding end wall of the water-oil separation box to the opposite end wall thereof;

preferably, in the two adjacent steps, the height of the step positioned at the rear is larger than that of the step positioned at the front;

preferably, in the adjacent two steps, the ratio of the height of the step positioned at the rear to the height of the step positioned at the front is 1-5.

Preferably, the coalescing oil absorption component is of a frame plate structure and comprises a support plate and an oil absorption layer, wherein the oil absorption layer comprises any one or a combination of a coalescing material layer, an oil absorption cotton layer and an oil absorption film layer; preferably, the oil absorption layer has 1-6 layers; preferably, the oil absorption layer is provided with pore channels for water molecules to pass through in a staggered way; preferably the diameter of the pore canal is 0.1-2mm; preferably, the proportion of the total area of the pore channels in each layer of the oil absorption layer is 5-20%; and/or

The second oil collecting assembly is made of oil absorbing cotton and/or elastic oil absorbing gel; and/or

In the water-oil separation unit, the ratio of the length of the second oil collecting assembly to the vertical length of the coalesced oil absorbing assembly is 10-100%; and/or

The thickness of the first oil collecting component is 2-50mm.

Preferably, the water-oil separation unit further comprises an oil tank connected to a discharge port of the oil delivery assembly for receiving the oil phase from the oil delivery assembly;

preferably, the water-oil separation unit further comprises a second cyclone connected to a bottom outlet of the oil tank, and used for extracting and cyclone separating the water phase deposited at the bottom of the oil tank, and outputting an oil phase from the top and an water phase from the bottom;

preferably, the water-oil separation unit further comprises an oil suction pump, and the oil suction pump is arranged on an oil delivery pipeline from the oil delivery assembly to the oil tank and is used for sucking the oil phase in the oil delivery assembly;

preferably, an equipment room is further arranged in the water-oil separation box, the equipment room is arranged below the water-oil separation room, and the oil tank and/or the second cyclone are/is arranged in the equipment room.

Preferably, the gas phase refining unit further comprises a first cyclone connected to the liquid phase outlet of the cyclone for receiving and cyclone separating the liquid phase from the cyclone, outputting a gas phase from the top thereof and a liquid phase from the bottom thereof; and/or

The gas-phase refining unit further comprises a filter which is respectively connected to the gas-phase outlet of the cyclone separator and/or the gas-phase outlet of the first cyclone, and is used for filtering and outputting the gas phase from the cyclone separator and/or the gas phase from the first cyclone.

To achieve the second object of the present invention, a process for pre-separating a Fischer-Tropsch product using the aforementioned system is provided.

Preferably, the method comprises the steps of:

(1) The Fischer-Tropsch product is conveyed into the gas-liquid deflector in the gas-liquid phase separation unit and is guided and output into the gas-liquid phase separation tank through a grid structure on the cylindrical main body wall; then, intercepting liquid phases carried in the gas phase sequentially by utilizing a gas-liquid deflector and a baffle plate assembly, outputting the gas phase from the top of the gas-liquid phase separation tank, and outputting the liquid phase from the bottom of the gas-liquid phase separation tank;

(2) Sending the gas phase output by the gas-liquid phase separation unit to the gas phase refining unit, performing cyclone separation by the cyclone separator, outputting the gas phase from the top of the cyclone separator, and outputting the liquid phase from the bottom of the cyclone separator;

(3) And sending the liquid phase output by the gas-liquid phase separation unit and the liquid phase output by the gas-phase refining unit to the water-oil phase separation unit, and carrying out water-oil separation by the water-oil phase separation box to respectively output a water phase and an oil phase.

The invention has the beneficial effects that:

the system for the Fischer-Tropsch product pre-separation and the method for the Fischer-Tropsch product pre-separation can be used for the Fischer-Tropsch product pre-separation, the multiphase separation effect is obviously improved, the liquid phases such as water and oil carried in a gas phase are reduced, the oil content of a water phase is reduced, the water content of an oil phase is reduced, and the product purity of the subsequent process is improved; the temperature of each stage of the system is reduced, and the energy consumption is reduced; the driving force of two-phase separation is increased, the load of the coalescent oil absorption component is reduced, the permeation flux is improved, and the efficiency is high;

the water-oil phase separation box in the water-oil phase separation unit adopts a box type structure, the upper space of the box body is wide, and the operation condition of the device is easy to monitor and overhaul and process adjustment are carried out at any time;

the coalescing oil absorption component adopts a plate frame type, so that the state of the coalescing and membrane component is easy to observe and sample;

the coalescing oil absorption assembly, the oil collection assembly and the oil transportation assembly are mutually independent, so that the assembly is simple, and the maintenance and the replacement of each assembly are easy;

the oil collecting components are in soft connection, and the second oil collecting component in the vertical direction is made of flexible high-elasticity oil absorbing cotton/oil absorbing gel and other materials, so that the liquid level change can be completely adapted;

the combined use of the gas-liquid phase separation unit, the cyclone separator and other small-volume equipment can obviously improve the preseparation effect of the gas phase and the liquid phase and the water phase and the oil phase in the liquid phase, and lighten the burden of the subsequent links;

The mutual entrainment of gas-liquid two phases and water phases and oil phases in the liquid phase in the Fischer-Tropsch product pre-separation process can be reduced, and the three-phase separation efficiency and the separation product purity of the water phases, the oil phases and the gas phases are improved; further reduces the product loss, avoids the pipeline blockage in the subsequent flow, and is beneficial to the stable operation of the downstream synthetic water treatment unit and the stable operation of the whole factory; the equipment occupies small area and has low cost.

Drawings

FIG. 1 is a schematic diagram of the system for Fischer-Tropsch product pre-separation of the present invention in one embodiment;

FIG. 2 is a schematic diagram of the structure of a gas-liquid deflector in one embodiment of the system for Fischer-Tropsch product pre-separation of the present invention;

FIG. 3 is a schematic top view of the uppermost baffle in one embodiment of the system for Fischer-Tropsch product pre-separation of the invention.

Detailed Description

The technical scheme and effects of the present invention are further described below with reference to specific embodiments. The following embodiments/examples are only for illustrating the contents of the present invention, and the present invention is not limited to the following embodiments or examples. Simple modifications of the invention using the inventive concept are within the scope of the invention as claimed.

The invention provides a system for pre-separation of Fischer-Tropsch products, which comprises a gas-liquid phase separation unit 1, a gas-phase refining unit 2 and a water-oil phase separation unit 3, as shown in figures 1-3; wherein,

the gas-liquid phase separation unit 1 comprises a gas-liquid phase separation tank 4 for feeding and separating the Fischer-Tropsch product into gas and liquid, outputting a gas phase to the gas-phase refining unit 2 from the top of the gas-liquid phase and outputting a liquid phase to the water-oil phase separation unit 3 from the bottom of the gas-liquid phase refining unit;

a gas-liquid deflector 5 and a baffle plate assembly 6 are coaxially arranged in the gas-liquid phase-splitting tank 4 from bottom to top in sequence;

the gas-liquid deflector 5 comprises a cylindrical body 51; a feed inlet is arranged on the bottom surface of the cylindrical main body 51 and is used for feeding Fischer-Tropsch products; at least the lower part of the cylinder wall of the cylinder-shaped main body 51 is of a grid structure and is used for carrying out gas-liquid separation on Fischer-Tropsch products entering the cylinder-shaped main body and guiding and outputting separated liquid phase from the grid structure to the gas-liquid phase separation tank 4;

the baffle assembly 6 comprises a fixed shaft 61 and baffles 62 coaxially arranged with the cylindrical body 51 for liquid entrapment of a portion of the gas phase separated from the fischer-tropsch product entering the gas-liquid deflector 5;

the gas phase refining unit 2 comprises a cyclone separator 21, wherein the cyclone separator 21 is connected to a gas phase outlet of the gas-liquid phase separation tank 4 in the gas-liquid phase separation unit 1 and is used for receiving the gas phase from the gas-liquid phase separation unit 1 and performing cyclone separation on the gas phase, outputting the gas phase from the top of the gas phase and outputting the liquid phase from the bottom of the gas phase;

The water-oil separation unit 3 comprises a water-oil separation tank 7, wherein the water-oil separation tank 7 is respectively connected to a liquid phase outlet of the gas-liquid separation unit 1 and a liquid phase outlet of the gas-phase refining unit 2, and is used for receiving and separating water and oil from the liquid phase of the gas-liquid separation unit 1 and the liquid phase of the gas-phase refining unit 2.

The invention discloses a system for pre-separating Fischer-Tropsch products, which mainly aims to perform preliminary separation on gas, oil and water in the Fischer-Tropsch products and paves for subsequent processing flows. The person skilled in the art will appreciate that the composition of the fischer-tropsch product entering the system comprises: (1) gas phase H-containing ₂ 、CO、CO ₂ 、CH ₄ Isophthys and lower carbon number hydrocarbons; (2) the oil phase contains organic matters such as alkane, alkene, higher carbon number oxygen-containing compounds and the like; (3) the aqueous phase contains lower carbon number oxygenates, and the like. Wherein liquid phase droplets such as oil phase and water phase are easy to be entrained in the gas phase, and flash is easy to occur due to temperature and pressure change in the process flowVapor phase changes can further exacerbate entrainment. The oil phase and the water phase are easy to form emulsification, entrainment and the like, and the oil-in-water and water-in-oil droplets are distributed in the water-oil phase, so that incomplete separation is caused, and the subsequent process is greatly influenced.

In the system for pre-separating the fischer-tropsch product, at least the lower part of the cylinder wall of the cylindrical main body 51 in the gas-liquid deflector 5 is provided with a grid structure, which is conducive to the foam breaking of the fischer-tropsch product, thereby releasing the gas phase therein, increasing the gas phase path and the contact area of the gas phase in the system, further realizing the preliminary separation of the gas phase and the liquid phase in the fischer-tropsch product, and guiding and outputting the separated liquid phase from the grid structure to the gas-liquid phase separation tank 4, and the separated gas phase goes upward; the different arrangement of the single-layer baffle plate and the double-layer baffle plate from bottom to top in the baffle plate assembly 6 is beneficial to increasing the gas phase path and the contact area of the gas phase in the system, thereby further promoting the separation of gas and liquid and reducing entrainment in the gas phase. The specific arrangement of the gas-liquid flow guider 5 and the baffle plate assembly 6 can effectively reduce gas phase turbulence, increase the gas phase path and the contact area of the gas phase in the system, and further effectively promote gas-liquid separation.

The system for pre-separating the Fischer-Tropsch products can be used for pre-separating the Fischer-Tropsch products, can be integrated into zero through the arrangement of the structures, firstly utilizes the gas-liquid phase separation unit 1 with smaller volume to perform preliminary separation on gas phase, increases the distance of gas flow and the contact area in the gas-liquid phase separation unit 1 through the gas-liquid flow guider 5 and the baffle plate assembly 6, and reduces the liquid phase carried in the gas phase; the gas phase output by the gas-liquid phase separation unit 1 enters the cyclone separator 21 in the gas phase refining unit 2 again, and the cyclone separator 21 is driven by front-rear pressure difference, so that liquid drops entrained in the gas phase are further blocked, and the mutual entrainment of gas-liquid two phases in the pre-separation process of the Fischer-Tropsch product can be reduced; the water-oil separation unit is arranged, so that the liquid phase can be further separated into water and oil; the multiphase (gas, water and oil three phases) separation efficiency and the purity of the separated products are improved; and the separation effect is improved, so that the operation temperature of each stage of the separation system can be reduced, and the energy consumption is reduced.

The person skilled in the art will appreciate that the fischer-tropsch product may be derived from the fischer-tropsch synthesis reactor 1'.

Those skilled in the art will appreciate that the baffles 62 may be replaced with a fine gauze.

In one embodiment, in the gas-liquid phase separation unit 1, the top surface of the cylindrical main body 51 is provided with a first gas hole 52, and the first gas hole 52 is provided in plurality and is dispersed, preferably uniformly dispersed, on the top surface of the cylindrical main body 51, so as to conduct diversion output and liquid interception on part of gas separated from the fed fischer-tropsch product; and/or

In the baffle assembly 6, the baffles 62 have n layers, n being greater than or equal to 1, such as 1, 2, 3, 4, 5, etc.; the single-layer baffle plates from bottom to top are coaxially fixed on the fixed shaft 61 in sequence at intervals, and a first gap is reserved between the baffle plates and the inner wall of the gas-liquid phase separation tank 4 and is used as a gas channel; the double baffle plates from bottom to top are sequentially and coaxially fixed on the inner wall of the gas-liquid phase separation tank 4 at intervals, and a second gap is reserved between the baffle plates and the fixed shaft and is used as a gas channel.

The arrangement of the first air holes is beneficial to the foam breaking of the Fischer-Tropsch product, so that the gas phase in the Fischer-Tropsch product is released; the specific arrangement of the first air hole and the baffle plate assembly is beneficial to further increasing the gas phase distance and the contact area of the gas phase in the system, so as to realize the primary separation of the gas phase and the liquid phase in the Fischer-Tropsch product.

In one embodiment, the baffles 62 are of a conical configuration; preferably, the cone angle of the baffle 62 is 60-120, such as 65 °, 70 °, 75 °, 80 °, 85 °, 90 °, 95 °, 100 °, 105 °, 110 °, and 115 °.

Those skilled in the art will appreciate that the baffles 62 may have other configurations, and in one embodiment, the baffles 62 have an N-pyramid configuration, where N.gtoreq.3, such as a triangular pyramid configuration, a rectangular pyramid configuration, a pentagonal pyramid configuration, etc.

To further reduce the entrainment of the liquid phase in the gas phase, the liquid phase in the gas phase is trapped, and in one embodiment, the plate surface of the baffle plate 62 is provided with a plurality of second air holes 621, and the second air holes 621 are distributed, preferably uniformly distributed, on the plate surface of the baffle plate 62; preferably, the diameter of the second air holes 621 is 1-3mm, such as 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm and 2.9mm; preferably, the second air holes 621 occupy a proportion of 0-20%, such as 1%, 2%, 3%, 4%, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18% and 19% of the total area of the baffle plate 62.

In order to conveniently and rapidly guide the trapped liquid phase to the gas-liquid phase separation tank 4, in one embodiment, a liquid guide groove is further arranged on the plate surface of the baffle plate 62, and the head end of the liquid guide groove is positioned on the plate surface of the baffle plate 62, and the tail end of the liquid guide groove is positioned at the edge of the baffle plate 62, so that the liquid drops condensed on the baffle plate 62 are guided to the bottom of the gas-liquid phase separation tank 4. Preferably, the width of the liquid guide groove is 2-5mm, such as 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3.0mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4.0mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm and 4.9mm; preferably the depth of the sump is 1-5mm, such as 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm, 2.0mm, 2.1mm, 2.2mm, 2.3mm, 2.4mm, 2.5mm, 2.6mm, 2.7mm, 2.8mm, 2.9mm, 3.0mm, 3.1mm, 3.2mm, 3.3mm, 3.4mm, 3.5mm, 3.6mm, 3.7mm, 3.8mm, 3.9mm, 4.0mm, 4.1mm, 4.2mm, 4.3mm, 4.4mm, 4.5mm, 4.6mm, 4.7mm, 4.8mm and 4.9mm.

In order to accelerate the flow of the liquid phase trapped by the baffle plate 62 to the gas-liquid phase separation tank 4, in one embodiment, the liquid guiding tank comprises a first liquid guiding tank 622, wherein the first liquid guiding tank 622 is arranged from the center to the edge of the baffle plate 62, that is, the head end of the first liquid guiding tank 622 is positioned at the center of the baffle plate 62, and the tail end of the first liquid guiding tank 622 is positioned at the edge of the baffle plate 62; preferably, the first liquid guiding groove 622 is arranged along the generatrix of the baffle plate 62; and/or

The liquid guide groove comprises a second liquid guide groove 623, wherein the head end of the second liquid guide groove 623 is positioned at 1/3-2/3 positions, such as 4/9, 1/2 and 5/9 positions, from the center to the edge of the baffle plate 62, namely, the head end of the second liquid guide groove 623 is positioned at 1/3-2/3 positions from the center to the edge of the baffle plate 62, and the tail end of the second liquid guide groove is positioned at the edge of the baffle plate 62.

In one embodiment, the liquid guide groove is provided on the upper surface of the baffle plate 62.

In one embodiment, the height to diameter ratio of the gas-liquid phase separation tank 4 is (1.5-4): 1, such as 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2.0:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1, 3.0:1, 3.1:1, 3.2:1, 3.3:1, 3.4:1, 3.5:1, 3.6:1, 3.7:1, 3.8:1, and 3.9:1; and/or

The height ratio of the gas-liquid phase separation tank 4 to the gas-liquid flow guider 5 is (1.5-3) 1,1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2.0:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1 and 2.9:1; and/or

The ratio of the diameters of the gas-liquid phase separation tank 4 and the gas-liquid deflector 5 is (1.5-5): 1, such as 1.5:1, 1.6:1, 1.7:1, 1.8:1, 1.9:1, 2.0:1, 2.1:1, 2.2:1, 2.3:1, 2.4:1, 2.5:1, 2.6:1, 2.7:1, 2.8:1, 2.9:1, 3.0:1, 3.1:1, 3.2:1, 3.3:1, 3.4:1, 3.5:1, 3.6:1, 3.7:1, 3.8:1, 3.9:1, 4.0:1, 4.1:1, 4.2:1, 4.3:1, 4.4:5:1, 4.6:1, 4.7:1, 4.8:1 and 4.9:1.

In one embodiment, the water-oil separation chamber 8 is arranged in the water-oil separation chamber 7, and the bottom surface of the water-oil separation chamber 8 is arranged in a descending manner in sequence along the direction from the feeding end wall of the water-oil separation chamber 7 to the opposite end wall thereof; the feed inlet of the water-oil separation chamber 8 is connected to the liquid phase outlet of the gas-liquid phase separation unit 1 and the liquid phase outlet of the gas-phase refining unit 2, and is used for feeding the liquid phase from the gas-liquid phase separation unit 1 and the liquid phase from the gas-phase refining unit 2;

an m-level water-oil separation unit, wherein m is more than or equal to 1, such as 1, 2, 3, 4, 5, 6 and the like, is arranged in the water-oil separation chamber 8 and is used for sequentially removing oil phases in the liquid phase from a feeding end to an opposite end; the water-oil separation unit comprises a coalescing oil suction assembly 81, an oil collection assembly 82 and an oil delivery assembly 83; in the m-level water-oil separation unit,

the coalescing oil suction assembly 81 is vertically arranged in the water-oil separation chamber 8, and is sequentially arranged at intervals from a feeding end to an opposite end in the water-oil separation chamber 8, so that the water-oil separation chamber 8 is divided into m water-oil separation sub-chambers 9 and water chambers 10 sequentially arranged from the feeding end to the opposite end;

the oil delivery assembly 83 is horizontally arranged at the upper part in the water-oil separation chamber 9 and is used for outputting oil phase from the oil collection assembly 82;

The oil collecting assembly 82 is suspended below the oil conveying assembly 83 and is flexibly connected with the oil conveying assembly 83, and is used for floating on the surface of the feed liquid phase;

the coalescing oil absorption assembly 81 is used for outputting an aqueous phase after passing through the liquid phase after oil collection through the oil collection assembly 82 and entrapping residual oil phase therein;

the water chamber 10 is used for receiving the water phase output by the m-level water-oil separation unit;

preferably, the oil collecting assembly 82 includes a first oil collecting assembly 821 in a horizontal direction and a second oil collecting assembly 822 in a vertical direction, the first oil collecting assembly 821 is horizontally floating on the surface of the feed liquid phase, and two ends of the second oil collecting assembly 822 are respectively connected to the first oil collecting assembly 821 and the oil delivery assembly 83, and are used for sequentially collecting the oil phase in the feed liquid phase.

Those skilled in the art understand that the water-oil two phases have a density difference, the water phase has a high density and the oil phase has a low density, so that the oil phase is located above the water phase; the invention utilizes the oil collecting component 82 and the oil conveying component 83 in the water-oil phase separating unit to upwards extract and output the oil phase in the liquid phase from the upper part by means of self-suction or external suction, and utilizes the coalescing oil absorbing component 81 to thoroughly coalesce and separate the oil phase from the liquid phase step by step and output the oil phase through the oil collecting component 82 and the oil conveying component 83; greatly increases the height range of the oil phase, fully utilizes the density difference of the water phase and the oil phase, ensures that the oil phase is separated more accurately and thoroughly, is beneficial to reducing the subsequent processing difficulty of the oil phase and the water phase and improves the purity of the product; the coalescing oil suction component 81, the oil collection component 82 and the oil delivery component 83 in the water-oil separation unit 3 are mutually independent, so that the assembly is simple, and the maintenance and the replacement of the components are easy;

The oil collecting assembly 82 and the oil conveying assembly 83 are in soft connection, the first oil collecting assembly 821 in the horizontal direction floats on the water surface, and oil molecules are adsorbed and collected in real time, so that the load of the agglomeration oil absorbing assembly positioned behind the first oil collecting assembly is greatly reduced; the second oil collecting component 822 in the vertical direction is made of flexible high-elasticity oil absorbing cotton/oil absorbing gel and other materials, and is connected between the oil conveying component 83 and the oil collecting component 82, and the oil conveying component 83 conveys the oil phase in the oil collecting component 82 in real time; after the liquid phase sequentially passes through each stage of coalescing oil absorption assembly 81, residual oil phase is effectively trapped step by step, the liquid level is gradually reduced, and the oil collection assembly 82 can completely adapt to the liquid level change;

the bottom of the water-oil separation chamber 8 of the water-oil separation unit is sequentially lowered, the liquid level of the water phase is lowered step by step, the water phase is vertically downward, and the oil phase is vertically upward for separation, so that the driving force of two-phase separation is increased, the load of a coalescent oil absorption assembly is reduced, the permeation flux is improved, and the separation efficiency is high;

the water-oil phase-splitting box 7 in the water-oil phase-splitting unit is of a box type structure, the upper space is wide, and the operation condition of the device is easy to monitor and overhaul and process adjustment are carried out at any time.

According to the invention, through the arrangement of the water-oil separation unit, the liquid phase can be further subjected to water-oil separation, the water phase and oil phase separation efficiency is improved, and the purity of the product separated by the subsequent unit is improved; and the separation effect is improved, so that the operation temperature of each stage of the separation system can be reduced, and the energy consumption is reduced.

In one embodiment, the bottom surface of the water-oil separation chamber 8 is arranged in a stepwise decreasing manner in sequence along the direction from the feeding end wall of the water-oil separation tank 7 to the opposite end wall thereof;

preferably, the m water-oil separation sub-chambers 9 and the bottom surfaces of the water chambers 10 are arranged in a stepwise decreasing manner in sequence in a direction from the feeding end wall of the water-oil separation tank 7 to the opposite end wall thereof;

preferably, the ratio of the height of the steps located at the rear to the height of the steps located at the front in two adjacent steps is 1-5, such as 1.0, 1.1, 1.2, 1.3, 1.4, 1.5, 1.6, 1.7, 1.8, 1.9, 2.0, 2.1, 2.2, 2.3, 2.4, 2.5, 2.6, 2.7, 2.8, 2.9, 3.0, 3.1, 3.2, 3.3, 3.4, 3.5, 3.6, 3.7, 3.8, 3.9, 4.0, 4.1, 4.2, 4.3, 4.4, 4.5, 4.6, 4.7, 4.8, 4.9 and 5.0.

In one embodiment, the coalescing oil absorbing assembly 81 is a frame plate structure, and includes a support plate and an oil absorbing layer, wherein the oil absorbing layer includes any one or more of a coalescing material layer, an oil absorbing cotton layer and an oil absorbing film layer; preferably the oil-absorbing layer has 1 to 6 layers, such as 3, 4 or 5 layers; preferably, the oil absorption layer is provided with pore channels for water molecules to pass through in a staggered way; preferably the diameter of the channels is 0.1-2mm, such as 0.1mm, 0.2mm, 0.3mm, 0.4mm, 0.5mm, 0.6mm, 0.7mm, 0.8mm, 0.9mm, 1.0mm, 1.1mm, 1.2mm, 1.3mm, 1.4mm, 1.5mm, 1.6mm, 1.7mm, 1.8mm, 1.9mm and 2.0mm; preferably, the total area of the channels in each layer of the oil-absorbing layer is 5-20%, such as 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19% and 20%; and/or

The second oil collecting component 822 is made of oil absorbing cotton and/or elastic oil absorbing gel; and/or

In the water-oil separation unit, the ratio of the length of the second oil collection assembly 822 to the vertical length of the coalescing oil absorption assembly 81 is 10-100%, such as 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, 80%, 85%, 90%, 95% and 100%; and/or

The thickness of the first oil collecting member 821 is 2 to 50mm, such as 2mm, 4mm, 6mm, 8mm, 10mm, 12mm, 14mm, 16mm, 18mm, 20mm, 22mm, 24mm, 26mm, 28mm, 30mm, 32mm, 34mm, 36mm, 38mm, 40mm, 42mm, 44mm, 46mm, 48mm and 50mm.

Those skilled in the art will appreciate that the length of the second oil collection assembly 822 refers to its length in the vertical direction; the thickness of the first oil collecting assembly 821 refers to its vertical thickness, i.e., its thickness in the vertical direction.

In the invention, the coalescing oil absorption component arranged in the water-oil separation chamber 8 of the water-oil phase separation box 7 adopts a plate frame type, so that the state of the coalescing and membrane component is easy to observe and sample.

In one embodiment, the water-oil separation unit 3 further comprises an oil tank 11, the oil tank 11 being connected to a discharge port of the oil delivery assembly 83 for receiving the oil phase from the oil delivery assembly 83;

Preferably, the water-oil separation unit 3 further comprises a second cyclone 12, and the second cyclone 12 is connected to the bottom outlet of the oil tank 11, and is used for extracting the water phase deposited at the bottom of the oil tank 11, performing cyclone separation on the water phase, and outputting an oil phase from the top and an aqueous phase from the bottom.

When the oil phase density is high and the viscosity is high, auxiliary suction may be performed by providing a pump or the like between the oil delivery unit and the oil tank. In one embodiment, the water-oil separation unit 3 further includes an oil suction pump provided on an oil line from the oil delivery assembly 83 to the oil tank 11 for sucking the oil phase in the oil delivery assembly 83.

In order to save space, in one embodiment, an equipment room 13 is further disposed in the water-oil separator 7, the equipment room 13 is disposed below the water-oil separator 8, and the oil tank 11 and/or the second cyclone 12 are disposed in the equipment room 13.

In one embodiment, the gas-phase refining unit 2 further comprises a first cyclone 22, the first cyclone 22 being connected to the liquid phase outlet of the cyclone 21 for receiving the liquid phase from the cyclone 21 and performing cyclone separation thereof, outputting a gas phase from the top thereof and a liquid phase from the bottom thereof; and/or

The gas-phase refining unit 2 further comprises a filter 23, wherein the filter 23 is respectively connected to the gas-phase outlet of the cyclone 21 and/or the gas-phase outlet of the first cyclone 22, and is used for filtering and outputting the gas phase from the cyclone 21 and/or the gas phase from the first cyclone 22; preferably, the filter 23 is filled with an adsorbent material such as oil absorbing cotton/water absorbing silica gel.

In the invention, the arrangement of the first cyclone 22 can cyclone and separate the gas phase in the liquid phase, so that the gas-liquid separation efficiency is further improved, and the gas-liquid separation effect and the purity of the separated product are improved; the filter 23 can further filter and intercept liquid phase (such as oil and water) in the gas phase, so that the preseparation effect of the gas phase and the liquid phase is obviously improved, and the burden of the subsequent links is reduced.

The system for pre-separating the Fischer-Tropsch products sequentially utilizes the gas-liquid phase separation unit, the gas-phase refining unit and the water-oil phase separation unit to realize the high separation of gas, oil and water phases; the liquid phase in the gas phase is separated and recovered more efficiently through components such as a cyclone separator, a cyclone, a filter and the like; through the bottom surface of water oil separating room in water oil phase separation unit and the setting of cohesion oil absorption subassembly, collection oil subassembly, defeated oil subassembly, realize that the oil phase is perpendicular upwards, and the aqueous phase separates perpendicularly downwards, increases two-phase separation driving force, reduces the load of coalescence oil absorption subassembly, has improved the infiltration flux, and separation efficiency is high.

The invention also provides a method for pre-separating the Fischer-Tropsch product by using the system.

In one embodiment, the method comprises the steps of:

(1) The Fischer-Tropsch product is conveyed into the gas-liquid deflector 5 in the gas-liquid phase separation unit 1 and is deflected and output into the gas-liquid phase separation tank 4 through a grid structure on the wall of the cylindrical main body 51; then, intercepting liquid phases carried in the gas phase sequentially by utilizing a gas-liquid deflector 5 and a baffle plate assembly 6, outputting the gas phase from the top of the gas-liquid phase separation tank 4, and outputting the liquid phase from the bottom of the gas-liquid phase separation tank 4;

(2) Sending the gas phase output by the gas-liquid phase separation unit 1 to the gas phase refining unit 2, performing cyclone separation by the cyclone separator 21, outputting the gas phase from the top and outputting the liquid phase from the bottom;

(3) The liquid phase output by the gas-liquid phase separation unit 1 and the liquid phase output by the gas-phase refining unit 2 are sent to the water-oil phase separation unit 3, and are subjected to water-oil separation by the water-oil phase separation box 7, and respectively output a water phase and an oil phase.

In one embodiment, the method further comprises:

in step (1), the liquid phase from the cyclone 21 is sent to the first cyclone 22 to be subjected to cyclone separation, and a gas phase is output from the top of the cyclone and a liquid phase is output from the bottom of the cyclone;

Preferably, the method further comprises:

in step (1), the gas phase from the cyclone 21 and/or the gas phase from the first cyclone 22 is sent to the filter 23 to be filtered and then output.

In one embodiment, the method further comprises:

in step (3), the oil phase from the oil delivery assembly 83 is delivered to the oil tank 11;

preferably, the method further comprises:

in the step (3), the water phase deposited at the bottom of the oil tank 11 is extracted by the second cyclone 12, and is subjected to cyclone separation, and the oil phase is output from the top and the water phase is output from the bottom.

The invention is further illustrated by the following specific examples and comparative examples.

Examples 1 to 4 (S1 to 4) and comparative examples 1 to 2 (D1 to 2)

Pre-separating the Fischer-Tropsch product using the system shown in FIGS. 1-3; wherein,

the system comprises a gas-liquid phase separation unit 1, a gas-phase refining unit 2 and a water-oil phase separation unit 3;

the gas-liquid phase separation unit 1 comprises a gas-liquid phase separation tank 4, wherein a gas-liquid flow director 5 and a baffle plate assembly 6 are coaxially arranged in the gas-liquid phase separation tank 4 from bottom to top in sequence;

the gas-liquid deflector 5 comprises a cylindrical body 51; a feed port is arranged on the bottom surface of the cylindrical main body 51; at least the lower part of the cylinder wall of the cylinder-shaped main body 51 is in a grid structure;

The baffle assembly 6 includes a stationary shaft 61 and a baffle 62 coaxially disposed with the cylindrical body 51; the baffle plate 62 has n layers, wherein n is more than or equal to 1; the single-layer baffle plates from bottom to top are coaxially fixed on the fixed shaft 61 in sequence at intervals, and a first gap is reserved between the baffle plates and the inner wall of the gas-liquid phase separation tank 4 and is used as a gas channel; the double-layer baffle plates from bottom to top are sequentially and coaxially fixed on the inner wall of the gas-liquid phase separation tank 4 at intervals, and a second gap is reserved between the baffle plates and the fixed shaft and is used as a gas channel; the baffle plate 62 is in a conical structure; the cone angle of the baffle 62 is 90 °;

the gas-phase refining unit 2 includes a cyclone 21, the cyclone 21 being connected to a gas-phase outlet of the gas-liquid phase separation tank 4 in the gas-liquid phase separation unit 1;

the water-oil phase separation unit 3 comprises a water-oil phase separation box 7, and the water-oil phase separation box 7 is respectively connected to a liquid phase outlet of the gas-liquid phase separation unit 1 and a liquid phase outlet of the gas-phase refining unit 2;

a water-oil separation chamber 8 is arranged in the water-oil separation chamber 7, and the bottom surface of the water-oil separation chamber 8 is sequentially lowered along the direction from the feeding end wall of the water-oil separation chamber 7 to the opposite end wall thereof; the feed inlet of the water-oil separation chamber 8 is connected to the liquid phase outlet of the gas-liquid phase separation unit 1 and the liquid phase outlet of the gas-phase refining unit 2;

An m-level water-oil separation unit is arranged in the water-oil separation chamber 8, and m is more than or equal to 1; the water-oil separation unit comprises a coalescing oil suction assembly 81, an oil collection assembly 82 and an oil delivery assembly 83; in the m-level water-oil separation unit,

the oil collecting assembly 82 includes a first oil collecting assembly 821 in a horizontal direction and a second oil collecting assembly 822 in a vertical direction, the first oil collecting assembly 821 is horizontally floating on the surface of the feed liquid phase, and two ends of the second oil collecting assembly 822 are respectively connected to the first oil collecting assembly 821 and the oil delivery assembly 83, so as to sequentially collect the oil phase in the feed liquid phase; wherein, in S1-4 and D1-2, the differences of the system are shown in Table 1 only;

The Fischer-Tropsch products were pre-separated using the system and method of the invention, and the separation effect comparison is shown in Table 1.

Table 1 comparison of the differentiation and separation effects of the systems for the pre-separation of Fischer-Tropsch products in S1-4 and D1-2

Note that: in the table "/" indicates none or no; n=0 represents no baffles, excluding the specific arrangement of baffle assemblies; m=0 represents that the water-oil separation unit is 0, excluding the specific arrangement of the water-oil separation unit.

As can be seen from the comparison of examples 1-4 with comparative examples 1-2 and the data in Table 1, the system and method of the present invention have low system temperature, can be performed at normal temperature and pressure, and have good phase separation effect, low gas phase entrainment rate, low oil content in the water phase and low water content in the oil phase in the phase separated product.

As can be seen from the comparison of comparative examples 1-2, comparative example 1 has poor phase separation effect, and the phase separation product has large gas phase entrainment rate, large water phase oil content and large oil phase water content, and the mutual entrainment of each phase is serious; in comparative example 2, three layers of baffles were provided to reduce the gas phase entrainment rate, the oil content in the aqueous phase and the water content in the oil phase to a small extent, but the effect was not remarkable.

As can be seen from a comparison between the embodiment 1 and the comparative example 2, in comparison with the comparative example 2, the embodiment 1 is provided with three layers of baffles, and the baffles are all fixed on the fixed shaft 61, and a grid structure is arranged at the lower part of the cylinder wall of the cylindrical main body 51 in the gas-liquid deflector, so as to help to break the fischer-tropsch product, thereby releasing the gas phase therein; and meanwhile, the cyclone separator 21 in the gas phase refining unit 2 is arranged, so that liquid drops entrained in gas phase are further blocked, and liquid drops entrained in the gas phase in the Fischer-Tropsch product pre-separation process can be reduced, and the upper limit of the gas phase entrainment rate is reduced to 0.4%.

As can be seen from the comparison of the embodiments 2-4 and the embodiment 1, compared with the embodiment 1, the single-layer baffle plates from bottom to top in the embodiments 2-4 are fixed on the fixed shaft 61, the double-layer baffle plates are fixed on the inner wall of the gas-liquid phase separation tank 4, so that the gas phase distance and the contact area of the gas phase in the system are increased; meanwhile, the first cyclone 22 and the filter 23 are also arranged in the gas-phase refining unit 2, so that the primary separation effect of the gas phase and the liquid phase in the Fischer-Tropsch product is further improved; the upper limit of the gas phase entrainment rate is further reduced to 0.2%.

As can be seen from the comparison between examples 2-4, on the basis of the other structural similarities, as the water-oil separation unit increases (m increases from 1 to 2 and 3 in turn), the oil content of the aqueous phase decreases in turn, and the water content of the oil phase decreases in turn; wherein the oil content of the water phase is reduced from 20-60mg/L to 10-30mg/L and then reduced to 0-20mg/L; the water content of the oil phase is reduced from 0-30mg/L to 0-15mg/L.

Claims

1. A system for pre-separation of fischer-tropsch products, characterized in that it comprises a gas-liquid phase separation unit (1), a gas-phase refining unit (2) and a water-oil phase separation unit (3); wherein,

the gas-liquid phase separation unit (1) comprises a gas-liquid phase separation tank (4) which is used for feeding Fischer-Tropsch products and separating gas from liquid, outputting gas phase to the gas-phase refining unit (2) from the top of the gas-liquid phase and outputting liquid phase to the water-oil phase separation unit (3) from the bottom of the gas-liquid phase refining unit;

A gas-liquid deflector (5) and a baffle plate assembly (6) are coaxially arranged in the gas-liquid phase-splitting tank (4) from bottom to top in sequence;

the gas-liquid deflector (5) comprises a cylindrical body (51); a feed inlet is arranged on the bottom surface of the cylindrical main body (51) and is used for feeding Fischer-Tropsch products; at least the lower part of the cylinder wall of the cylinder-shaped main body (51) is of a grid structure and is used for carrying out gas-liquid separation on Fischer-Tropsch products entering the cylinder-shaped main body and guiding and outputting separated liquid phase from the grid structure to the gas-liquid phase separation tank (4);

the baffle assembly (6) comprises a fixed shaft (61) and a baffle (62) coaxially arranged with the cylindrical body (51) for liquid interception of a portion of the gas phase separated from the Fischer-Tropsch product entering the gas-liquid deflector (5);

the gas-phase refining unit (2) comprises a cyclone separator (21), wherein the cyclone separator (21) is connected to a gas-phase outlet of the gas-liquid phase separation tank (4) in the gas-liquid phase separation unit (1) and is used for receiving and cyclone separating the gas phase from the gas-liquid phase separation unit (1), outputting the gas phase from the top and outputting the liquid phase from the bottom;

the water-oil separation unit (3) comprises a water-oil separation box (7), wherein the water-oil separation box (7) is respectively connected to a liquid phase outlet of the gas-liquid separation unit (1) and a liquid phase outlet of the gas-phase refining unit (2) and is used for receiving and separating water from a liquid phase from the gas-liquid separation unit (1) and a liquid phase from the gas-phase refining unit (2).

2. The system of claim 1, wherein the system further comprises a controller configured to control the controller,

in the gas-liquid phase separation unit (1), a plurality of first air holes (52) are formed in the top surface of the cylindrical main body (51), and the first air holes (52) are distributed on the top surface of the cylindrical main body (51) and are used for conducting flow guiding output and liquid interception on partial gas separated from the fed Fischer-Tropsch product; and/or

In the baffle plate assembly (6), the baffle plate (62) is provided with n layers, and n is more than or equal to 1; the single-layer baffle plates from bottom to top are sequentially and coaxially fixed on the fixed shaft (61) at intervals, and a first gap is reserved between the baffle plates and the inner wall of the gas-liquid phase separation tank (4) and is used as a gas channel; the double-layer baffle plates from bottom to top are sequentially and coaxially fixed on the inner wall of the gas-liquid phase separation tank (4) at intervals, and a second gap is reserved between the baffle plates and the fixed shaft and is used as a gas channel;

preferably, a liquid guide groove is further arranged on the plate surface of the baffle plate (62), and the head end of the liquid guide groove is positioned on the plate surface of the baffle plate (62), and the tail end of the liquid guide groove is positioned at the edge of the baffle plate (62) and is used for guiding liquid drops condensed on the baffle plate (62) to the bottom of the gas-liquid phase separation tank (4);

Preferably, the liquid guide groove comprises a first liquid guide groove (622), and the first liquid guide groove (622) is arranged from the center to the edge of the baffle plate (62); and/or

The liquid guide groove comprises a second liquid guide groove (623), and the head end of the second liquid guide groove (623) is positioned at 1/3-2/3 of the position from the center to the edge of the baffle plate (62).

3. The system according to claim 1 or 2, wherein,

the height-diameter ratio of the gas-liquid phase separation tank (4) is (1.5-4): 1; and/or

The height ratio of the gas-liquid phase separation tank (4) to the gas-liquid flow guider (5) is (1.5-3) 1; and/or

The diameter ratio of the gas-liquid phase separation tank (4) to the gas-liquid flow guider (5) is (1.5-5): 1.

4. A system according to any one of claims 1 to 3, wherein,

a water-oil separation chamber (8) is arranged in the water-oil separation chamber (7), and the bottom surface of the water-oil separation chamber (8) is sequentially lowered along the direction from the feeding end wall to the opposite end wall of the water-oil separation chamber (7); the feed inlet of the water-oil separation chamber (8) is connected to the liquid phase outlet of the gas-liquid phase separation unit (1) and the liquid phase outlet of the gas-phase refining unit (2) and is used for feeding the liquid phase from the gas-liquid phase separation unit (1) and the liquid phase from the gas-phase refining unit (2);

An m-level water-oil separation unit is arranged in the water-oil separation chamber (8), wherein m is more than or equal to 1 and is used for sequentially removing oil phases in the liquid phase from a feeding end to an opposite end; the water-oil separation unit comprises a coalescing oil suction assembly (81), an oil collection assembly (82) and an oil delivery assembly (83); in the m-level water-oil separation unit,

the coalescing oil absorption component (81) is vertically arranged in the water-oil separation chamber (8), and is sequentially arranged in the water-oil separation chamber (8) at intervals from a feeding end to an opposite end, so that the water-oil separation chamber (8) is divided into m water-oil separation sub-chambers (9) and water chambers (10) which are sequentially arranged from the feeding end to the opposite end;

the oil conveying component (83) is horizontally arranged at the upper part in the water-oil separation sub-chamber (9) and is used for outputting oil phase from the oil collecting component (82);

the oil collecting assembly (82) is suspended below the oil conveying assembly (83), is in flexible connection with the oil conveying assembly (83) and is used for floating on the surface of the feed liquid phase;

the coalescing oil absorption component (81) is used for outputting an aqueous phase after passing through the liquid phase after oil collection through the oil collection component (82) and entrapping residual oil phase therein;

the water chamber (10) is used for receiving the water phase output by the m-level water-oil separation unit;

Preferably, the oil collecting assembly (82) comprises a first oil collecting assembly (821) in the horizontal direction and a second oil collecting assembly (822) in the vertical direction, the first oil collecting assembly (821) is horizontally floated on the surface of the feed liquid phase, and two ends of the second oil collecting assembly (822) are respectively connected to the first oil collecting assembly (821) and the oil conveying assembly (83) and are used for sequentially collecting oil phases in the feed liquid phase.

5. The system of claim 4, wherein the system further comprises a controller configured to control the controller,

the bottom surface of the water-oil separation chamber (8) is arranged in a stepwise decreasing manner in sequence along the direction from the feeding end wall of the water-oil separation box (7) to the opposite end wall;

preferably, the bottom surfaces of the m water-oil separation chambers (9) and the water chamber (10) are arranged in a stepwise decreasing manner in sequence along the direction from the feeding end wall of the water-oil separation chamber (7) to the opposite end wall thereof;

6. The system of claim 4 or 5, wherein the system comprises a plurality of sensors,

in the water-oil separation unit, the ratio of the length of the second oil collecting component (822) to the vertical length of the coalesced oil absorbing component (81) is 10-100%; and/or

The first oil collection assembly (821) has a thickness of 2-50mm.

7. The system of any one of claims 4-6, wherein,

the water-oil separation unit (3) further comprises an oil tank (11), wherein the oil tank (11) is connected to a discharge port of the oil delivery assembly (83) and is used for receiving an oil phase from the oil delivery assembly (83);

preferably, the water-oil separation unit (3) further comprises a second cyclone (12), wherein the second cyclone (12) is connected to a bottom outlet of the oil tank (11) and is used for extracting water phase deposited at the bottom of the oil tank (11) and performing cyclone separation on the water phase, and outputting an oil phase from the top and an aqueous phase from the bottom;

preferably, the water-oil separation unit (3) further comprises an oil suction pump, which is arranged on an oil delivery pipeline from the oil delivery assembly (83) to the oil tank (11) and is used for sucking the oil phase in the oil delivery assembly (83);

preferably, an equipment chamber (13) is further arranged in the water-oil phase separation box (7), the equipment chamber (13) is arranged below the water-oil separation chamber (8), and the oil tank (11) and/or the second cyclone (12) are arranged in the equipment chamber (13).

8. The system of any one of claims 1-7, wherein,

The gas-phase refining unit (2) further comprises a first cyclone (22), wherein the first cyclone (22) is connected to a liquid phase outlet of the cyclone separator (21) and is used for receiving the liquid phase from the cyclone separator (21) and performing cyclone separation on the liquid phase, outputting gas phase from the top of the cyclone separator and outputting the liquid phase from the bottom of the cyclone separator; and/or

The gas-phase refining unit (2) further comprises a filter (23), wherein the filter (23) is respectively connected to the gas-phase outlet of the cyclone separator (21) and/or the gas-phase outlet of the first cyclone (22) and is used for filtering and outputting the gas phase from the cyclone separator (21) and/or the gas phase from the first cyclone (22).

9. A process for pre-separating fischer-tropsch products using the system according to any one of claims 1 to 8.

10. The method according to claim 9, characterized in that it comprises the steps of:

(1) The Fischer-Tropsch product is conveyed into the gas-liquid deflector (5) in the gas-liquid phase separation unit (1), and is guided and output into the gas-liquid phase separation tank (4) through a grid structure on the cylinder wall of the cylindrical main body (51); then, intercepting liquid phase carried in the gas phase sequentially by utilizing a gas-liquid deflector (5) and a baffle plate assembly (6), outputting the gas phase from the top of the gas-liquid phase separation tank (4), and outputting the liquid phase from the bottom of the gas-liquid phase separation tank (4);

(2) Sending the gas phase output by the gas-liquid phase separation unit (1) to the gas phase refining unit (2), performing cyclone separation by the cyclone separator (21), outputting the gas phase from the top and outputting the liquid phase from the bottom;

(3) And (3) conveying the liquid phase output by the gas-liquid phase separation unit (1) and the liquid phase output by the gas-phase refining unit (2) to the water-oil phase separation unit (3), and carrying out water-oil separation through the water-oil phase separation box (7) to output a water phase and an oil phase respectively.