Poly-alpha-olefin synthetic oil catalyst removal system and method

Abstract

The invention provides a poly-alpha-olefin synthetic oil catalyst removal system and a poly-alpha-olefin synthetic oil catalyst removal method. The system comprises polymerization reaction equipment, stirring and mixing equipment, layering equipment and a monomer separation unit, a feeding hole of the stirring and mixing equipment is connected with a discharging hole of the polymerization reaction equipment, a discharging hole of the stirring and mixing equipment is connected with a feeding hole of the layering equipment, and an absorbent inlet of the stirring and mixing equipment is respectively connected with an absorbent source and a poly-alpha-olefin synthesis oil layer outlet of the layering equipment; a poly-alpha-olefin synthesis oil layer outlet of the layering equipment is connected with a feeding hole of the monomer separation unit; a fluid discharge pipeline is arranged on a connecting pipeline between an absorbent inlet of the stirring and mixing equipment and a poly-alpha-olefin synthesis oil layer outlet of the layering equipment.

Description

Technical Field

[0001] The present invention relates to a catalyst removal system and method for poly-α-olefin synthetic oil. Background Art

[0002] Class IV lubricant base oil - poly-α-olefin synthetic oil is currently the synthetic lubricant base oil with the best performance, having excellent properties such as high viscosity index, low volatility, and good low-temperature fluidity, and can be applicable to various harsh working conditions. It is not only widely used in the civilian industry but also the main source of special lubricating base oil for industries such as aviation, aerospace, and military. The global demand for poly-α-olefin synthetic oil has always shown a trend of supply falling short of demand. However, during the production of poly-α-olefin synthetic oil, a catalyst system containing BF 3 is usually required, and BF 3 in the poly-α-olefin synthetic oil will cause corrosion of equipment and pipelines, bringing many inconveniences to enterprises, and will also reduce the quality of poly-α-olefin synthetic oil. Therefore, it is necessary to remove BF 3 from the poly-α-olefin synthetic oil. Currently, the commonly used method for removing BF 3 in poly-α-olefin synthetic oil is caustic washing. However, caustic washing will generate a large amount of fluorine-containing and oil-containing wastewater, increasing the burden on the sewage treatment plant.

[0003] Therefore, some researchers have tried to use other methods to remove BF 3 from poly-α-olefin synthetic oil. However, these methods all have many problems. For example, the method of reducing the pressure of the polymerization product to flash off the excessive boron trifluoride for BF 3 removal, and for another example, the method of gas-liquid separation after heating for BF 3 removal. These methods usually have a low BF 3 removal rate and still need to be combined with caustic washing or alkali addition and neutralization treatment, and are prone to cause BF 3 to accumulate in the separation equipment and corrode the equipment.

[0004] In summary, there is an urgent need to study a poly-α-olefin synthetic oil catalyst removal technology that can avoid the generation of fluorine-containing wastewater and reduce the corrosion of pipelines by BF 3 . Summary of the Invention

[0005] The purpose of the present invention is to provide a technical solution for removing poly-α-olefin synthetic oil catalyst that can avoid the generation of fluorine-containing wastewater and reduce the corrosion of pipelines by BF 3 .

[0006] To solve the above problems, the present invention provides the following two aspects of technical solutions.

[0007] In a first aspect, the present invention provides a catalyst removal system for poly-α-olefin synthetic oil, wherein the system includes a polymerization reaction device, a stirring and mixing device, a separation device, and a monomer separation unit;

[0008] The feed inlet of the stirring and mixing device is connected to the discharge outlet of the polymerization reaction device, the discharge outlet of the stirring and mixing device is connected to the feed inlet of the separation device, the absorbent inlet of the stirring and mixing device is respectively connected to the adsorbent source and the poly-α-olefin synthetic oil layer outlet of the separation device, and the poly-α-olefin synthetic oil layer outlet of the separation device is connected to the feed inlet of the monomer separation unit; a fluid discharge pipeline is provided on the pipeline connecting the absorbent inlet of the stirring and mixing device and the poly-α-olefin synthetic oil layer outlet of the separation device.

[0009] In the above-mentioned catalyst removal system for poly-α-olefin synthetic oil, a stirring and mixing device and a separation device are arranged between the polymerization reaction device and the monomer separation unit. With the cooperation of the stirring and mixing device and the separation device, it is possible to effectively and continuously remove the catalyst system containing BF in the synthetic oil during the synthesis of poly-α-olefin. 3 And no fluorine-containing wastewater is generated.

[0010] According to a preferred embodiment of the first aspect, the polymerization reaction device is a polymerization reactor.

[0011] According to a preferred embodiment of the first aspect, the polymerization reaction device is provided with a feed inlet, a BF 3 inlet, a solid-liquid catalyst inlet, and a discharge outlet; among them, the feed inlet and the solid-liquid catalyst inlet are arranged at the bottom of the polymerization reaction device, and the BF 3 inlet is arranged at the top of the polymerization reaction device;

[0012] More preferably, a stirrer is provided inside the polymerization reaction device;

[0013] More preferably, the polymerization reaction device is provided with a temperature control part, and the temperature control part is provided with a heat transfer medium inlet and a heat transfer medium outlet.

[0014] According to a preferred embodiment of the first aspect, the catalyst removal system for poly-α-olefin synthetic oil further includes a drying device, and the discharge outlet of the drying device is connected to the feed inlet of the polymerization reaction device.

[0015] According to a preferred embodiment of the first aspect, the monomer outlet of the monomer separation unit is connected to the feed inlet of the polymerization reaction device.

[0016] According to a preferred embodiment of the first aspect, a sampling point is provided on the pipeline connecting the absorbent inlet of the stirring and mixing device and the poly-α-olefin synthetic oil layer outlet of the separation device.

[0017] According to a preferred embodiment of the first aspect, the monomer separation unit includes a heating device and a monomer stripping column; the feed inlet of the heating device is connected to the outlet of the poly-α-olefin synthetic oil layer of the stratifying device, and the outlet of the heating device is connected to the feed inlet of the monomer stripping column;

[0018] More preferably, the monomer separation unit further includes a gas-liquid separation device; the gas outlet of the monomer stripping column is connected to the feed inlet of the gas-liquid separation device, and the liquid outlet of the gas-liquid separation device serves as the monomer outlet of the monomer separation unit.

[0019] In a second aspect, the present invention provides a method for removing a poly-α-olefin synthetic oil catalyst, which is carried out using the poly-α-olefin synthetic oil catalyst removal system provided in the first aspect. The method includes:

[0020] Feeding an α-olefin feedstock oil and a catalyst system containing BF 3 to a polymerization reaction device, and carrying out a polymerization reaction of the α-olefin feedstock oil under the catalyst system containing BF 3 in the polymerization reaction device; the catalyst system containing BF 3 includes gaseous BF 3 and a catalyst;

[0021] Feeding the polymerization reaction product in the polymerization reaction device, an alcohol absorbent, and the absorbent layer conveyed out from the stratifying device to a stirring and mixing device, and carrying out mixing in the stirring and mixing device; wherein, BF 3 forms a complex product of BF 3 and alcohol with the alcohol absorbent;

[0022] Feeding the product after mixing in the stirring and mixing device to a stratifying device for stratification, obtaining an absorbent layer and a poly-α-olefin synthetic oil layer, and respectively conveying the absorbent layer and the poly-α-olefin synthetic oil layer out from the stratifying device; wherein, the catalyst system containing BF 3 exists in the absorbent layer, and the complex product of BF 3 and the alcohol absorbent and the catalyst are dissolved in this layer; wherein, a part of the absorbent layer conveyed out from the stratifying device is conveyed to the stirring and mixing device;

[0023] Feeding the poly-α-olefin synthetic oil layer conveyed out from the stratifying device to a monomer separation unit for α-olefin monomer separation.

[0024] According to a preferred embodiment of the second aspect, feeding an α-olefin feedstock oil and a catalyst system containing BF 3 to a polymerization reaction device, and carrying out a polymerization reaction of the α-olefin feedstock oil under the catalyst system containing BF 3 in the polymerization reaction device is achieved by the following method:

[0025] The α-olefin feedstock and the catalyst are fed from the bottom of the polymerization reaction equipment to the polymerization reaction equipment, and at the same time, gaseous BF 3 is fed from the top of the polymerization reaction equipment to the polymerization reaction equipment for pressure regulation, and the polymerization reaction of the α-olefin feedstock is carried out in the polymerization reaction equipment under a catalyst system containing BF 3 .

[0026] According to a preferred embodiment of the second aspect, the catalyst includes at least one of a monohydric alcohol and a dihydric alcohol; more preferably, the catalyst includes at least one of a monohydric alcohol having no more than 10 carbon atoms and a dihydric alcohol having no more than 10 carbon atoms.

[0027] According to a preferred embodiment of the second aspect, the temperature of the polymerization reaction is 10-100 °C, the pressure is 0.05-2.0 MPaG, and the time is 0.2-40 h.

[0028] According to a preferred embodiment of the second aspect, the mass ratio of the α-olefin feedstock, BF 3 , and the catalyst is: 100:0.0001-0.01:0.1-1.

[0029] According to a preferred embodiment of the second aspect, the method further includes: detecting the alcohol absorbent content of the absorbent layer delivered out of the stratifying device to ensure that all BF 3 is used for alcohol absorbent complexation.

[0030] According to a preferred embodiment of the second aspect, the mass ratio of the alcohol absorbent delivered to the stirring and mixing equipment to the BF 3 delivered to the polymerization reaction equipment is 4-40:1.

[0031] According to a preferred embodiment of the second aspect, the alcohol absorbent includes at least one of monohydric alcohols having 1-10 carbon atoms.

[0032] According to a preferred embodiment of the second aspect, the α-olefin feedstock contains at least one of α-olefins having 4-14 carbon atoms;

[0033] more preferably, in the α-olefin feedstock, the mass content of α-olefins having 4-14 carbon atoms ≥ 80%.

[0034] According to a preferred embodiment of the second aspect, the mass content of n-α-olefins having 4-14 carbon atoms in the α-olefin feedstock ≥ 60%.

[0035] According to a preferred embodiment of the second aspect, the method further includes: drying the α-olefin feedstock before it is fed to the polymerization reaction equipment.

[0036] According to a preferred embodiment of the second aspect, the transportation of the poly-α-olefin synthetic oil layer discharged from the stratifying device to the monomer separation unit for α-olefin monomer separation includes:

[0037] heating the poly-α-olefin synthetic oil layer discharged from the stratifying device to 100-300 °C and then transporting it to the monomer stripping tower, where α-olefin monomer separation is carried out by means of nitrogen stripping in the monomer stripping tower;

[0038] More preferably, the separated gas enters the gas-liquid separation device for cooling and then gas-liquid separation, and the separated liquid phase is the α-olefin monomer; Even more preferably, the α-olefin monomer is transported to the polymerization reaction device for recycling;

[0039] More preferably, the temperature of the monomer stripping tower is 10-200 °C, the pressure is 5 Kpa-150 KPa (absolute pressure), the mass ratio of gas to oil is 0.01-0.5, and the injection pressure of nitrogen is 0.10-2 MPa (gauge pressure).

[0040] Compared with the prior art, the technical solution provided by the present invention has the following beneficial effects:

[0041] 1. The technical solution provided by the present invention can realize the "harmless" separation of the catalyst and BF in the α-olefin polymerization product, and solve the problem of difficult treatment of wastewater and waste residue in the traditional water caustic washing process and solid adsorption process. 3 2. The preferred mode of the technical solution provided by the present invention can further realize the efficient recycling on the basis of the "harmless" separation of the catalyst and BF in the α-olefin polymerization product, and improve the technical economy.

[0042] 3. The technical solution provided by the present invention uses an alcohol absorbent to complex and absorb the gaseous BF dissolved in the α-olefin polymerization product, 3 realize zero emission of BF gas, have no pollution to the environment, and can reduce the corrosion effect on the device.

[0043] 3. The technical solution provided by the present invention uses an alcohol absorbent to complex and absorb the gaseous BF dissolved in the α-olefin polymerization product, 3 to achieve zero emission of BF 3 gas, which is environmentally friendly and can reduce the corrosion of the device. BRIEF DESCRIPTION OF THE DRAWINGS

[0044] Figure 1 It is a schematic structural diagram of the poly-α-olefin synthetic oil catalyst removal system in Example 1. DETAILED DESCRIPTION OF THE INVENTION

[0045] In order to have a clearer understanding of the technical features, objectives and beneficial effects of the present invention, the technical solution of the present invention will be described in detail below, but it should not be construed as a limitation on the scope of implementation of the present invention.

[0046] Example 1

[0047] This embodiment provides a catalyst removal system for poly-α-olefin synthetic oil, as Figure 1 shown. This system includes a drying device 1, a polymerization reaction device 2, a stirring and mixing device 3, a layering device 4, and a monomer separation unit.

[0048] The polymerization reaction device 2 is provided with a feed inlet, a BF 3 inlet, a solid-liquid phase catalyst inlet, and a discharge outlet; the feed inlet and the solid-liquid phase catalyst inlet are arranged at the bottom of the polymerization reaction device 2, and the BF 3 inlet is arranged at the top of the polymerization reaction device 2; a stirrer is arranged inside the polymerization reaction device 2; the polymerization reaction device 2 is provided with a temperature control part, and the temperature control part is provided with a heat transfer medium inlet and a heat transfer medium outlet.

[0049] The monomer separation unit includes a heating device 5, a monomer stripping tower 6, and a gas-liquid separation device 7.

[0050] The discharge outlet of the drying device 1 is connected to the feed inlet of the polymerization reaction device 2, the feed inlet of the stirring and mixing device 3 is connected to the discharge outlet of the polymerization reaction device 2, the discharge outlet of the stirring and mixing device 3 is connected to the feed inlet of the layering device 4, the absorbent inlet of the stirring and mixing device 3 is respectively connected to the absorbent source and the poly-α-olefin synthetic oil layer outlet of the layering device 4, and the poly-α-olefin synthetic oil layer outlet of the layering device 4 is connected to the feed inlet of the heating device 5; the discharge outlet of the heating device 5 is connected to the feed inlet of the monomer stripping tower 6; the gas outlet of the monomer stripping tower 6 is connected to the feed inlet of the gas-liquid separation device 7, and the liquid outlet of the gas-liquid separation device 7 is connected to the feed inlet of the polymerization reaction device 2; wherein, a fluid discharge pipeline and a sampling point are arranged on the connecting pipeline between the absorbent inlet of the stirring and mixing device 3 and the poly-α-olefin synthetic oil layer outlet of the layering device 4.

[0051] Among them, the polymerization reaction device 2 selects a polymerization reaction kettle.

[0052] Among them, the drying device 2 selects parallel molecular sieve drying towers.

[0053] Among them, the gas-liquid separation device 7 selects a gas-liquid separation tank.

[0054] Among them, the stirring and mixing device 3 selects a stirring tank.

[0055] Among them, the monomer stripping tower 6 selects a plate tower or a packed tower.

[0056] Example 2

[0057] This embodiment provides a method for removing a catalyst from poly-α-olefin synthetic oil. This method is carried out using the catalyst removal system for poly-α-olefin synthetic oil provided in Example 1. This method includes:

[0058] Step 1: The α-olefin feedstock stream A at a temperature of 25°C and a pressure of 0.05 MPa enters the drying equipment 1 at a flow rate of 500 kg / h for drying and water removal.

[0059] Step 2: The dried α-olefin feedstock stream B (with a water content of 10 μg / g) from the drying equipment 1 is mixed with the liquid-phase α-olefin monomer stream J separated by the gas-liquid separation equipment 7 and fed into the polymerization reaction equipment 2 from the bottom of the polymerization reaction equipment 2. Meanwhile, the catalyst stream (methanol) C enters the polymerization reaction equipment 2 from the bottom of the polymerization reaction equipment 2 at a flow rate of 2.4 kg / h. Meanwhile, the gas-phase BF 3 stream D enters the polymerization reaction equipment 2 from the top of the polymerization reaction equipment 2 at a flow rate of 0.78 kg / h, and the α-olefin polymerization reaction takes place in the polymerization reaction equipment 2. Among them, the temperature of the polymerization reaction equipment 2 is 10°C, the pressure is 0.05 MPaG, and the residence time of the material in the polymerization reaction equipment 2 is 5 h.

[0060] Step 3: The polymerization reaction product stream E (with a flow rate of approximately 599.9 kg / h during the normal operation stage) in the polymerization reaction equipment 2 enters the stirring and mixing equipment 3. Meanwhile, the alcohol absorbent stream F at a temperature of 25°C and a pressure of 0.4 MPa (gauge pressure) (methanol is used in this embodiment) enters the stirring equipment 3 at a flow rate of 2.6 kg / h. At the same time, the absorbent layer stream G at a temperature of 30°C and a pressure of 0.8 MPa (gauge pressure) (with a flow rate of approximately 3.2 kg / h during the normal operation stage) sent out from the separation equipment 4 is transported to the stirring and mixing equipment 3 and mixed evenly in the stirring and mixing equipment 3. Among them, BF 3 forms a complex with the alcohol absorbent to form BF 3 a complex product with alcohol;

[0061] The product mixed evenly in the stirring and mixing equipment 3 is transported to the separation equipment 4 for separation to obtain an absorbent layer and a poly-α-olefin synthetic oil layer, and the absorbent layer and the poly-α-olefin synthetic oil layer are respectively transported out from the separation equipment. Among them, the catalyst system containing BF 3 exists in the absorbent layer, and BF 3 the complex product formed by BF 3 complexed with the alcohol absorbent and the catalyst are dissolved in the alcohol absorbent. Among them, a part of the absorbent layer sent out from the separation equipment 4 is used as the absorbent layer stream G and transported to the stirring and mixing equipment 3.

[0062] Step 4: The laminar flow H of poly-α-olefin synthetic oil transported out from the stratifying device 4 is heated to 100 °C by the heating device 5 and then enters the middle section of the monomer stripping tower 6. At the same time, the nitrogen gas stream I enters the monomer stripping tower 6 from the bottom of the monomer stripping tower 6. α-olefin monomer nitrogen stripping separation is carried out in the monomer stripping tower 6. The α-olefin monomer and nitrogen gas are taken out from the top of the monomer stripping tower 6 as a gas phase and enter the gas-liquid separation device 7 for cooling and gas-liquid separation to obtain the liquid-phase α-olefin monomer stream J. The liquid-phase α-olefin monomer stream J is mixed with the α-olefin raw material oil stream B (water content is 10 μg / g) dried by the drying device 1 for recycling; the crude poly-α-olefin synthetic oil stream K is output from the bottom of the monomer stripping tower 6.

[0063] The parameters and compositions of each logistics are shown in Table 1.

[0064] Table 1

[0065]

[0066]

[0067] Example 3

[0068] This example provides a method for removing poly-α-olefin synthetic oil catalyst. This method is carried out using the poly-α-olefin synthetic oil catalyst removal system provided in Example 1. This method includes:

[0069] Step 1: The α-olefin raw material oil stream A at a temperature of 25 °C and a pressure of 0.05 MPa enters the drying device 1 at a flow rate of 1255.2 kg / h for drying and water removal.

[0070] Step 2: The α-olefin raw material oil stream B (water content is 10 μg / g) dried by the drying device 1 is mixed with the liquid-phase α-olefin monomer stream J separated by the gas-liquid separation device 7 and is transported from the bottom of the polymerization reaction device 2 into the polymerization reaction device 2. At the same time, the catalyst stream C (octanol) enters the polymerization reaction device 2 from the bottom of the polymerization reaction device 2 at a flow rate of 5.4 kg / h. At the same time, the gas phase BF 3 stream D enters the polymerization reaction device 2 from the top of the polymerization reaction device 2 at a flow rate of 2.1 kg / h for α-olefin polymerization reaction in the polymerization reaction device 2. Among them, the temperature of the polymerization reaction device 2 is 50 °C, the pressure is 1.0 MPaG, and the residence time of the material in the polymerization reaction device 2 is 10 h.

[0071] Step 3: The polymerization reaction product stream E (with a flow rate of approximately 1404.3 kg / h during normal operation) in the polymerization reaction equipment 2 enters the stirring and mixing equipment 3. Meanwhile, the alcohol absorbent stream F at a temperature of 25°C and a pressure of 0.4 MPa (gauge pressure) (octanol is used in this embodiment) enters the stirring equipment 3 at a flow rate of 6.7 kg / h. At the same time, the absorbent layer stream G at a temperature of 40°C and a pressure of 0.8 MPa (gauge pressure) (with a flow rate of approximately 12.2 kg / h during normal operation) transported from the separation equipment 4 is transported to the stirring and mixing equipment 3 and is mixed evenly in the stirring and mixing equipment 3; among them, BF 3 Complexes with the alcohol absorbent to form BF 3 Complex product with alcohol;

[0072] The product after being mixed evenly in the stirring and mixing equipment 3 is transported to the separation equipment 4 for separation to obtain an absorbent layer and a poly-α-olefin synthetic oil layer, and the absorbent layer and the poly-α-olefin synthetic oil layer are respectively transported out from the separation equipment; among them, the catalyst system containing BF 3 Exists in the absorbent layer, and BF 3 The BF complexed with the alcohol absorbent to form 3 The complex product with alcohol and the catalyst are dissolved in the alcohol absorbent; among them, a part of the absorbent layer transported out from the separation equipment 4 is used as the absorbent layer stream G and transported to the stirring and mixing equipment 3.

[0073] Step 4: The poly-α-olefin synthetic oil layer stream H transported out from the separation equipment 4 is heated to 180°C by the heating equipment 5 and then enters the middle section of the monomer stripping tower 6 from the monomer stripping tower 6. Meanwhile, the nitrogen stream I enters the monomer stripping tower 6 from the bottom of the monomer stripping tower 6. α-olefin monomer nitrogen stripping separation is carried out in the monomer stripping tower 6. The α-olefin monomer and nitrogen are taken out from the top of the monomer stripping tower 6 as a gas phase and enter the gas-liquid separation equipment 7 for cooling and gas-liquid separation to obtain the liquid-phase α-olefin monomer stream J. The liquid-phase α-olefin monomer stream J is mixed with the α-olefin raw oil stream B (with a water content of 10 μg / g) dried by the drying equipment 1 for recycling; the poly-α-olefin synthetic oil crude product stream K is output from the bottom of the monomer stripping tower 6.

[0074] The parameters and compositions of each logistics are shown in Table 2.

[0075] Table 2

[0076] Logistics number A C E F G H Composition wt% Water 0.015 0.000 0.001 0.000 0 0.001 Nitrogen 0 0 0.006 0 0 0.006 Boron trifluoride 0 0 0.146 0 0 0.000 Alcohol absorbent 0 0 0 100 0 0.000 Catalyst 0 100 0.395 0 100 0.000 1-Octene 96.085 0 7.6 0 0 7.641 Isooctene 1.8 0 0.142 0 0 0.143 Internal olefin 1.9 0 0.15 0 0 0.151 n-Octane 0.2 0 2.554 0 0 2.568 Dimer 0 0 14.758 0 0 14.838 Trimer 0 0 47.782 0 0 48.042 Tetramer 0 0 21.522 0 0 21.639 Pentamer and above 0 0 4.943 0 0 4.970 Temperature / °C 25 24 36 25 40 180 Pressure / MPa (gauge) 0.05 0.1 0.05 0.4 0.8 0.4 Total mass flow rate (kg / hr) 1255.2 5.4 1404.3 6.7 12.2 1398.8

[0077] Example 4

[0078] This embodiment provides a method for removing a poly-α-olefin synthetic oil catalyst. This method is carried out using the poly-α-olefin synthetic oil catalyst removal system provided in Example 1. This method includes:

[0079] Step 1: The α-olefin feedstock stream A at a temperature of 25°C and a pressure of 0.05 MPa enters the drying equipment 1 at a flow rate of 1255.2 kg / h for drying and water removal.

[0080] Step 2: The dried α-olefin feedstock stream B (with a water content of 10 μg / g) from the drying equipment 1 is mixed with the liquid-phase α-olefin monomer stream J separated by the gas-liquid separation equipment 7 and fed into the polymerization reaction equipment 2 from the bottom. At the same time, the catalyst stream C (pentanol) enters the polymerization reaction equipment 2 from the bottom at a flow rate of 11.2 kg / h. At the same time, the gas-phase BF 3 stream D enters the polymerization reaction equipment 2 from the top at a flow rate of 2.1 kg / h, and the α-olefin polymerization reaction takes place in the polymerization reaction equipment 2. Among them, the temperature of the polymerization reaction equipment 2 is 100°C, the pressure is 2.0 MPaG, and the residence time of the material in the polymerization reaction equipment 2 is 10 h.

[0081] Step 3: The polymerization reaction product stream E (with a flow rate of about 1404.3 kg / h during normal operation) in the polymerization reaction equipment 2 enters the stirring and mixing equipment 3. At the same time, the alcohol absorbent stream F (pentanol is used in this embodiment) at a temperature of 25°C and a pressure of 0.4 MPa (gauge pressure) enters the stirring equipment 3 at a flow rate of 6.7 kg / h. At the same time, the absorbent layer stream G at a temperature of 50°C and a pressure of 0.8 MPa (gauge pressure) (with a flow rate of about 17.9 kg / h during normal operation) sent out from the separation equipment 4 is transported to the stirring and mixing equipment 3 and mixed evenly in the stirring and mixing equipment 3. Among them, BF 3 forms a complex with the alcohol absorbent to form BF 3 a complex product with alcohol;

[0082] The product mixed evenly in the stirring and mixing equipment 3 is transported to the separation equipment 4 for separation to obtain an absorbent layer and a poly-α-olefin synthetic oil layer, and the absorbent layer and the poly-α-olefin synthetic oil layer are respectively transported out of the separation equipment. Among them, the catalyst system containing BF 3 exists in the absorbent layer, and BF 3 the complex product formed by BF 3 complexed with the alcohol absorbent and the catalyst are dissolved in the alcohol absorbent. Among them, a part of the absorbent layer sent out from the separation equipment 4 is transported to the stirring and mixing equipment 3 as the absorbent layer stream G.

[0083] Step 4: The laminar flow H of poly-α-olefin synthetic oil transported out from the layering device 4 is heated to 300 °C by the heating device 5 and then enters the middle section of the monomer stripping tower 6. At the same time, the nitrogen gas stream I enters the monomer stripping tower 6 from the bottom of the monomer stripping tower 6. α-olefin monomer nitrogen stripping separation is carried out in the monomer stripping tower 6. The α-olefin monomer and nitrogen are taken out from the top of the monomer stripping tower 6 as a gas phase and enter the gas-liquid separation device 7 for cooling and gas-liquid separation to obtain the liquid-phase α-olefin monomer stream J. The liquid-phase α-olefin monomer stream J is mixed with the α-olefin raw oil stream B (water content is 10 μg / g) dried by the drying device 1 for recycling; the crude poly-α-olefin synthetic oil stream K is output from the bottom of the monomer stripping tower 6.

[0084] The parameters and compositions of each logistics are shown in Table 3.

[0085] Table 3

[0086] Logistics number A C E F G H Composition wt% Water 0.015 0.000 0.001 0.000 0 0.001 Nitrogen 0 0 0.006 0 0 0.006 Boron trifluoride 0 0 0.146 0 0 0.000 Alcohol absorbent 0 0 0 100 0 0.000 Catalyst 0 100 0.8 0 100 0.000 1-Decene 96.085 0 7.2 0 0 7.241 Isodecene 1.8 0 0.142 0 0 0.143 Internal olefin 1.9 0 0.15 0 0 0.151 n-Decane 0.2 0 2.554 0 0 2.568 Dimer 0 0 18.758 0 0 18.838 Trimer 0 0 51.782 0 0 52.242 Tetramer 0 0 15.522 0 0 15.839 Pentamer and above 0 0 2.943 0 0 2.970 Temperature / °C 25 24 50 25 50 175 Pressure / MPa (gauge) 0.05 0.1 0.8 0.4 0.8 0.4 Total mass flow rate (kg / hr) 1255.2 5.4 1404.3 6.7 17.9 1386.4

[0087] The above are only the preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A catalyst removal system for poly-α-olefin synthetic oil, wherein, the system includes a polymerization reaction device, a stirring and mixing device, a stratification device and a monomer separation unit; the feed port of the stirring and mixing device is connected to the discharge port of the polymerization reaction device, the discharge port of the stirring and mixing device is connected to the feed port of the stratification device, the absorbent inlet of the stirring and mixing device is respectively connected to the adsorbent source and the poly-α-olefin synthetic oil layer outlet of the stratification device, and the poly-α-olefin synthetic oil layer outlet of the stratification device is connected to the feed port of the monomer separation unit; a fluid discharge pipeline is arranged on the pipeline connecting the absorbent inlet of the stirring and mixing device and the poly-α-olefin synthetic oil layer outlet of the stratification device.

2. The system according to claim 1, wherein, The polymerization reaction equipment is provided with a feed inlet, a BF 3 inlet, a solid-liquid phase catalyst inlet, and a discharge outlet; among them, the feed inlet and the solid-liquid phase catalyst inlet are arranged at the bottom of the polymerization reaction equipment, and there is a BF 3 inlet arranged at the top of the polymerization reaction equipment; preferably, a stirrer is provided in the polymerization reaction device; preferably, the polymerization reaction device is provided with a temperature control part, and the temperature control part is provided with a heat transfer medium inlet and a heat transfer medium outlet.

3. The system according to claim 1, wherein, the catalyst removal system for poly-α-olefin synthetic oil further includes a drying device, and the discharge port of the drying device is connected to the feed port of the polymerization reaction device.

4. The system according to claim 1, wherein, the monomer outlet of the monomer separation unit is connected to the feed port of the polymerization reaction device.

5. The system according to claim 1, wherein, a sampling point is arranged on the pipeline connecting the absorbent inlet of the stirring and mixing device and the poly-α-olefin synthetic oil layer outlet of the stratification device.

6. The system according to claim 1, wherein, the monomer separation unit includes a heating device and a monomer stripping tower; the feed port of the heating device is connected to the poly-α-olefin synthetic oil layer outlet of the stratification device, and the discharge port of the heating device is connected to the feed port of the monomer stripping tower; preferably, the monomer separation unit further includes a gas-liquid separation device; the gas outlet of the monomer stripping tower is connected to the feed port of the gas-liquid separation device, and the liquid outlet of the gas-liquid separation device is used as the monomer outlet of the monomer separation unit.

7. A method for removing a catalyst from poly-α-olefin synthetic oil, which uses the catalyst removal system for poly-α-olefin synthetic oil according to any one of claims 1-6, and the method includes: Feed the α-olefin feedstock and the catalyst system containing BF 3 to the polymerization reaction equipment, and carry out the polymerization reaction of the α-olefin feedstock under the catalyst system containing BF 3 in the polymerization reaction equipment; the catalyst system containing BF 3 comprises gaseous BF 3 and a catalyst; The polymerization reaction product in the polymerization reaction apparatus, the alcohol absorbent, and the absorbent layer conveyed out from the stratifying apparatus are conveyed into a stirring and mixing apparatus for mixing; wherein, BF 3 forms a complex with the alcohol absorbent to form BF 3 a complex product with the alcohol; Transfer the product after mixing evenly in the stirring and mixing equipment to a layering equipment for layering to obtain an absorbent layer and a poly-α-olefin synthetic oil layer, and separately transfer the absorbent layer and the poly-α-olefin synthetic oil layer out of the layering equipment; wherein, a catalyst system containing BF 3 exists in the absorbent layer, and the BF 3 complex formed by BF 3 and the alcohol absorbent and the catalyst are dissolved in the alcohol absorbent; wherein, a part of the absorbent layer transferred out of the layering equipment is transferred to the stirring and mixing equipment; transporting the poly-α-olefin synthetic oil layer transported out of the stratification device to the monomer separation unit for separating α-olefin monomers.

8. The method according to claim 7, wherein, Feed the α-olefin feedstock and the catalyst system containing BF 3 to the polymerization reaction equipment, and the polymerization reaction of the α-olefin feedstock under the catalyst system containing BF 3 is achieved by the following method: Feed the α-olefin feedstock and the catalyst from the bottom of the polymerization reaction equipment to the polymerization reaction equipment, and at the same time feed gaseous BF 3 from the top of the polymerization reaction equipment to the polymerization reaction equipment for pressure regulation, and carry out the polymerization reaction of the α-olefin feedstock under the catalyst system containing BF 3 in the polymerization reaction equipment.

9. The method according to claim 7, wherein, the catalyst includes at least one of a monohydric alcohol and a dihydric alcohol; preferably, the catalyst includes at least one of a monohydric alcohol with a carbon number not exceeding 10 and a dihydric alcohol with a carbon number not exceeding 10; and / or the alcohol absorbent includes at least one of monohydric alcohols with 1-10 carbon atoms.

10. The method according to claim 7, wherein, the temperature of the polymerization reaction is 10-100 °C, the pressure is 0.05-2.0 MPaG, and the time is 0.2-40 h.

11. The method according to claim 7, wherein, α-olefin feedstock, BF 3 The mass ratio of the catalyst is: 100:0.0001 - 0.5:0.1 - 1.

12. The method according to claim 7, wherein, The mass ratio of the alcohol absorbent delivered to the stirring and mixing equipment to BF delivered to the polymerization reaction equipment is: 4-40:

1. 3 ​ 13. The method according to claim 7, wherein, the α-olefin feedstock oil contains at least one of α-olefins with 4-14 carbon atoms; Preferably, in the α-olefin feedstock oil, the content of α-olefins having 4 to 14 carbon atoms is ≥80%; Preferably, the mass content of normal α-olefins having 4 to 14 carbon atoms in the α-olefin feedstock oil is ≥60%.

14. According to the method described in claim 7, wherein, transporting the poly-α-olefin synthetic oil layer transported out of the stratifying device to the monomer separation unit for α-olefin monomer separation includes: heating the poly-α-olefin synthetic oil layer transported out of the stratifying device to 100 - 300 °C and then transporting it to the monomer stripping tower, and carrying out α-olefin monomer separation in the monomer stripping tower by means of nitrogen stripping; Preferably, the separated gas enters the gas-liquid separation device for cooling and then gas-liquid separation, and the separated liquid phase is the α-olefin monomer; more preferably, the α-olefin monomer is transported to the polymerization reaction device for recycling; Preferably, the temperature of the monomer stripping tower is 10 - 200 °C, the pressure is 5 KPa - 150 KPa (absolute pressure), the mass ratio of gas to oil is 0.01 - 0.5, and the injection pressure of nitrogen is 0.10 - 2 MPa (gauge pressure).

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