A method for separating products of solution polymerization reaction

Abstract

This invention belongs to the field of materials synthesis and discloses a method for separating products from solution polymerization reactions to solve the problem of high energy consumption in traditional sequential separation. The method includes separation via distillation or integrated separation via a partitioned column. Distillation separation includes solvent pre-separation or 1-octene pre-separation. The solvent pre-separation scheme includes a solvent pre-separation column, a C6 separation column, a 1-hexene separation column, a solvent separation column, and a 1-octene light separation column. The 1-octene pre-separation scheme includes a 1-octene pre-separation column, a 1-octene heavy separation column, a C6 separation column, a 1-hexene separation column, and a heavy separation column. The separated products include C6 byproducts, 1-hexene, 1-octene, recycled solvent, and heavy components. The C6 byproducts include methylcyclopentane and methylenecyclopentane. The recycled solvent is further purified using amino-functionalized adsorption materials. This method breaks through the fixed separation sequence, reduces energy consumption, and improves solvent recovery and purity, making it suitable for industrial production.

Description

Technical Field

[0001] This invention belongs to the field of materials synthesis, and specifically relates to a method for separating products of solution polymerization reaction. Background Technology

[0002] Solution polymerization is one of the core methods for preparing polymer materials such as polyolefins and synthetic rubber. Its reaction product system has an extremely complex composition, including not only α-olefin components such as methylcyclopentane, methylenecyclopentane, 1-hexene, and 1-octene, but also circulating solvents such as methylcyclohexane, n-hexane, and n-heptane, as well as heavy components with C10 and above.

[0003] Currently, the industry generally adopts a fixed-sequence separation scheme to handle the separation requirements of α-olefins from solution polymerization products. This scheme is based on the difference in boiling points of the components and follows a separation path of low-boiling-point α-olefins, medium-boiling-point α-olefins, circulating solvent, high-boiling-point α-olefins, and heavy components: First, methylcyclopentane and methylenecyclopentane need to be separated at low temperature to avoid excessive volatilization in subsequent high-temperature operations; then, 1-hexene is separated in a targeted manner to prevent it from mixing with the circulating solvent; then, the circulating solvent is recovered by heating; finally, 1-octene is purified and the heavy components are processed.

[0004] However, this fixed-sequence separation scheme has significant technical shortcomings, with excessive energy consumption being particularly prominent. On the one hand, each separation tower must be strictly adapted to the characteristics of the current separated components, leading to frequent adjustments to operating parameters: lower temperatures must be maintained when separating methylcyclopentane and methylenecyclopentane, while the temperature must be gradually increased when separating 1-octene and heavy components. The energy loss during the repeated heating and cooling of the towers is enormous. Moreover, to avoid the entrainment of preceding components affecting subsequent separations, each tower must maintain a high reflux ratio, with some towers even exceeding 5 reflux ratios, significantly increasing steam and electricity consumption. On the other hand, the series dependence of sequential separation exacerbates the energy burden. If the target component is not completely separated in the previous tower, the subsequent tower must compensate by increasing the operating temperature or extending the separation time, further increasing energy consumption.

[0005] As green chemistry and cost reduction and efficiency improvement become the mainstream of industry development, the shortcomings of traditional sequential separation schemes, such as high energy consumption and limited purification effect, are becoming increasingly prominent. The industry urgently needs a solution polymerization reaction product separation method that breaks through the limitations of fixed separation sequence, optimizes component separation logic to reduce energy consumption, and has high purification capabilities. Summary of the Invention

[0006] The purpose of this invention is to provide a low-energy-consumption method for separating solution polymerization products that achieves efficient purification of circulating solvents. Addressing the high energy consumption and low solvent recovery and purity of traditional sequential separation methods, this invention breaks through the fixed separation sequence by integrating two distillation paths with a partition column, reducing energy consumption and improving solvent recovery. Simultaneously, amino-functionalized adsorbent materials remove trace impurities from the circulating solvent, meeting high-purity requirements and making it suitable for industrial production.

[0007] The technical solution adopted by the present invention to achieve the above objectives is as follows:

[0008] A method for separating products from a solution polymerization reaction includes separation via a distillation path or separation via an integrated partitioned column. The separation via a distillation path includes solvent pre-separation or 1-octene pre-separation, and the separation via an integrated partitioned column includes separation via a single partitioned column or separation via a double partitioned column.

[0009] Preferably, the solvent pre-separation scheme includes a solvent pre-separation tower, a C6 separation tower, a 1-hexene separation tower, a solvent separation tower, and a 1-octene light separation tower.

[0010] Preferably, the separation scheme for 1-octene pre-separation includes a 1-octene pre-separation tower, a 1-octene heavy separation tower, a C6 separation tower, a 1-hexene separation tower, and a heavy separation tower.

[0011] Preferably, the separation products of the separation method include C6 byproducts, 1-hexene, 1-octene, and recycled solvent and heavy components.

[0012] Preferably, the C6 byproducts include methylcyclopentane and methylenecyclopentane.

[0013] Preferably, in the solvent pre-separation, the operating temperature of the solvent pre-separation tower is 100-200℃ and the operating pressure is 0-0.2MPaG.

[0014] Preferably, in the solvent pre-separation, the operating temperature of the C6 separation tower is 70-170℃ and the operating pressure is 0-0.2MPaG.

[0015] Preferably, in the solvent pre-separation, the operating temperature of the 1-hexene separation tower is 60-130℃ and the operating pressure is 0-0.2MPaG.

[0016] Preferably, in the solvent pre-separation, the operating temperature of the solvent separation tower is 110-200℃ and the operating pressure is 0.1-0.3MPaG.

[0017] Preferably, in the solvent pre-separation, the operating temperature of the 1-octene light separation tower is 80-210℃ and the operating pressure is -0.1-0.1 MPaG.

[0018] Preferably, in the solvent pre-separation, the stream drawn from the top of the solvent pre-separation tower contains more than 99 wt% of the C6 component and the lighter component C6- from the feed, and 10-90 wt% of the total solvent component in the feed is drawn. The stream drawn from the bottom of the tower contains the solvent component remaining after the top of the tower is drawn, as well as more than 99 wt% of 1-octene and heavy components from the feed.

[0019] Preferably, in the 1-octene pre-separation, the operating temperature of the 1-octene pre-separation tower is 120-220℃ and the operating pressure is 0.1-0.3MPaG.

[0020] Preferably, in the 1-octene pre-separation, the operating temperature of the 1-octene heavy separation tower is 100-190℃ and the operating pressure is 0.1-0.3MPaG.

[0021] Preferably, in the 1-octene pre-separation, the operating temperature of the C6 separation tower is 70-170℃ and the operating pressure is 0-0.2MPaG.

[0022] Preferably, in the 1-octene pre-separation, the operating temperature of the 1-hexene separation tower is 60-130℃ and the operating pressure is 0-0.2MPaG.

[0023] Preferably, in the 1-octene pre-separation, the operating temperature of the heavy removal tower is 80-210℃ and the operating pressure is -0.1-0.1MPaG.

[0024] Preferably, in the 1-octene pre-separation, the stream collected from the top of the 1-octene pre-separation tower contains more than 99 wt% of the solvent, C6 component and lighter component C6- from the feed, and collects 10-90 wt% of the total 1-octene component from the feed. The stream collected from the bottom of the tower contains the remaining 1-octene component after the top of the tower, and more than 99 wt% of the heavy components from the feed.

[0025] Preferably, in the solvent pre-separation, the top stream of the solvent pre-separation tower is separated to obtain the top stream, and the bottom stream is separated to obtain the bottom stream.

[0026] Preferably, in the solvent pre-separation, the overhead stream enters the 1-hexene separation column, the C6 component is separated at the top of the column, and the recycled solvent is separated at the bottom of the column.

[0027] Preferably, in the solvent pre-separation, the C6 component enters the C6 separation tower, 1-hexene is separated at the top of the tower, and C6 by-products are separated at the bottom of the tower, including methylcyclopentane and methylenecyclopentane.

[0028] Preferably, in the solvent pre-separation, the bottom stream enters the solvent separation tower, the top of the tower separates to obtain the circulating solvent, and the bottom of the tower separates to obtain the intermediate component.

[0029] Preferably, in the solvent pre-separation, the intermediate component enters a 1-octene light separation column, where 1-octene is separated at the top of the column and heavy components are separated at the bottom.

[0030] Preferably, in the 1-octene pre-separation, the top stream of the 1-octene pre-separation tower is separated to obtain the pre-separation tower top stream, and the bottom stream is separated to obtain the tower bottom stream.

[0031] Preferably, in the 1-octene pre-separation, the overhead stream from the pre-separation column enters the 1-octene heavy separation column, the overhead stream from the heavy separation column is obtained from the top of the column, and 1-octene is obtained from the bottom of the column.

[0032] Preferably, in the 1-octene pre-separation, the overhead stream from the heavy separation column enters the 1-hexene separation column, where the C6 component is separated at the top and the recycled solvent is separated at the bottom.

[0033] Preferably, in the 1-octene pre-separation, the C6 component enters the C6 separation tower, 1-hexene is separated at the top of the tower, and C6 by-products are separated at the bottom of the tower, including methylcyclopentane and methylenecyclopentane.

[0034] Preferably, in the 1-octene pre-separation, the bottom stream of the column enters the deweighting column, 1-octene is separated at the top of the column, and heavy components are separated at the bottom of the column.

[0035] Preferably, in the single-divided-wall column separation, 1-hexene is obtained from the top of the single-divided-wall column, C6 by-product is obtained from the side stream product, and solvent is obtained from the bottom of the column.

[0036] Preferably, in the single-divided-wall column separation, the distillation temperature of the single-divided-wall column is 50-250℃, and the operating pressure is 0-0.3 MPaG.

[0037] Preferably, in the single-partition column separation, the C6 byproducts include methylcyclopentane and methylenecyclopentane.

[0038] Preferably, in the double-walled tower separation, the separation towers of the double-walled tower include a first partition tower and a second partition tower.

[0039] Preferably, in the double-walled column separation, the side stream product of the first walled column yields 1-octene, the bottom of the column yields a heavy component, and the top of the column yields 1-hexene, C6 byproducts, and solvent. This product then flows to the second walled column.

[0040] Preferably, in the double-walled column separation, 1-hexene is obtained from the top of the second partitioned column, C6 byproduct is obtained from the side stream product, and solvent is obtained from the bottom of the column.

[0041] Preferably, in the double-walled column separation, the distillation temperature of the first partition column is 50-300℃ and the operating pressure is -0.1-0.3 MPaG.

[0042] Preferably, in the double-walled column separation, the distillation temperature of the second partition column is 50-250℃, and the operating pressure is 0.01-0.3 MPaG.

[0043] Preferably, in the dual-wall column separation, the C6 byproducts include methylcyclopentane and methylenecyclopentane.

[0044] Preferably, the catalyst for solution polymerization includes ligand a, transition metal compound b, and activator c.

[0045] Preferably, ligand a includes a PNP ligand, a PNNP ligand, and a rigid linker group.

[0046] Preferably, transition metal compound b is a metal compound of group IVB-VIII.

[0047] Preferably, activator c is a compound containing a Group IIIA metal.

[0048] Preferably, the circulating solvent is purified by an amino-functionalized adsorbent material to obtain a purified circulating solvent.

[0049] Preferably, the core layer of the amino-functionalized adsorbent material includes graphene oxide.

[0050] Preferably, the shell of the amino-functionalized adsorbent material is formed by grafting a modifier with a crosslinking agent.

[0051] Preferably, the modifier includes 3,4-dihydroxyphenylacetamide and N-isopropyl-1,3-diaminopropane.

[0052] Preferably, the mass ratio of graphene oxide to 3,4-dihydroxyphenylacetamide is 2:0.5-3.

[0053] Preferably, the mass ratio of 3,4-dihydroxyphenylacetamide to N-isopropyl-1,3-diaminopropane is 2:0.5-5. 3,4-Dihydroxyphenylacetamide and N-isopropyl-1,3-diaminopropane together construct a highly efficient adsorption system. 3,4-Dihydroxyphenylacetamide, through its hydroxyl groups, forms hydrogen bonds and covalent bonds with oxygen-containing groups on the surface of graphene oxide, achieving tight coating of graphene oxide, optimizing the matrix structure, preventing graphene oxide agglomeration, providing stable attachment sites for subsequent functionalization modifications, and regulating the dispersion of the material in the circulating solvent system to ensure sufficient exposure of adsorption sites. N-isopropyl-1,3-diaminopropane, under the cross-linking effect of glutaraldehyde, is grafted onto the coated graphene surface with amino groups as linking sites. The amino groups in its molecule can serve as specific adsorption sites, binding with residual catalyst transition metal ions through coordination, further enhancing the selective adsorption capacity for trace impurities, ultimately achieving deep purification of the circulating solvent.

[0054] More preferably, the modifier includes N-vinyl-N-methylacetamide, and the mass ratio of 3,4-dihydroxyphenylacetamide to N-vinyl-N-methylacetamide is 2:0.5-5. N-vinyl-N-methylacetamide, on the one hand, helps anchor N-isopropyl-1,3-diaminopropane, enhancing its grafting stability on the graphene surface and preventing functional group detachment; on the other hand, it introduces additional nitrogen-containing functional groups, synergistically constructing denser specific adsorption sites with the amino group of N-isopropyl-1,3-diaminopropane, strengthening the capture ability of residual transition metal ions of the catalyst in the circulating solvent through coordination; optimizing the dispersibility of the material in the circulating solvent dispersion, ensuring sufficient exposure of adsorption sites and efficient contact with impurities, thereby improving the removal efficiency of the adsorbent material for trace impurities.

[0055] This invention also provides a method for preparing refined reaction raw materials, comprising:

[0056] The reaction feedstock includes solvent and ethylene. Fresh ethylene is transported into the boundary area via pipeline from outside the boundary, heated to 85-95°C, and then enters the ethylene deoxidizer from top to bottom for deoxidation. It then enters the ethylene carbon monoxide removal tower from top to bottom to remove carbon monoxide. Next, it enters the ethylene cooler to cool to 30-40°C, and then enters the ethylene dryer / carbon dioxide remover from top to bottom to remove moisture and carbon dioxide, yielding refined ethylene. Fresh solvent is transported into the boundary area via pipeline from outside the boundary. It passes through a crude solvent coalescer to remove a large amount of water and is then transported to a solvent degassing tower for light component removal. The bottom liquid enters the solvent cooler to cool to 30-40°C. The solvent is then transported from bottom to top to the solvent dryer to remove moisture. After drying, the solvent enters the solvent protection bed from bottom to top to remove other polar substances. After filtration through a solvent filter, refined solvent is obtained.

[0057] Preferably, the solvent is one or more of methylcyclohexane, n-hexane, and n-heptane.

[0058] This invention also provides a method for preparing a catalyst solution, comprising:

[0059] The catalyst was added to a purified solvent and stirred at 35-45℃ and 150-250 rpm for 20-40 min to obtain a catalyst solution. The catalyst consisted of ligand a, a transition metal compound b, and an activator c.

[0060] Preferably, ligand a includes a PNP ligand, a PNNP ligand, and a rigid linker group.

[0061] More preferably, ligand a is 1,4-phenylenebis(diphenylphosphinemethylamine).

[0062] Preferably, transition metal compound b is a metal compound of group IVB-VIII.

[0063] More preferably, the transition metal compound b is zirconium tetrachloride.

[0064] Preferably, activator c is a compound containing a Group IIIA metal.

[0065] More preferably, activator c is methylaluminoxane.

[0066] Preferably, the molar ratio of ligand a to transition metal compound b is 1:0.1-100.

[0067] More preferably, the molar ratio of ligand a to transition metal compound b is 1:0.1-1.

[0068] Preferably, the molar ratio of ligand a to activator c is 1:0.1-5000.

[0069] More preferably, the molar ratio of ligand a to activator c is 1:0.1-1000.

[0070] More preferably, the molar ratio of ligand a to activator c is 1:0.1-500.

[0071] Preferably, the mass of the catalyst is measured by the mass of ligand a, and the mass-to-volume ratio of ligand a to the purified solvent is 10-30 g: 1 L.

[0072] The present invention also provides a method for preparing the reaction product, comprising:

[0073] Refined ethylene is pressurized to 2.5-6.5 MPaG using a fresh ethylene compressor and delivered to the reactor unit. Refined solvent is also pressurized to 2.5-6.5 MPaG using a pump and delivered to the reactor unit. Hydrogen is pressurized to 2.5-6.5 MPaG using a hydrogen compressor and delivered to the reactor unit. After mixing, the mixture enters the reactor feed cooler, where it is cooled and the outlet temperature is controlled at -10-40°C before entering the first reactor. The catalyst solution is pressurized to 2.5-6.5 MPaG using a pump and sent to the first reactor. The mixture is held in the reactor for 20-60 minutes at 35-120°C and 2.5-6.5 MPaG, then sent to the termination reactor. A terminator is added to terminate the reaction, yielding the reaction product.

[0074] Preferably, the volume ratio of the refining solvent to the refined ethylene is 2L:0.5-2m. 3 .

[0075] Preferably, the volume ratio of the purified solvent to the catalyst solution is 2L:0.5-2mL.

[0076] Preferably, the terminator is isooctanol.

[0077] Preferably, the volume ratio of the purified solvent to the terminator is 2L:0.5-2mL.

[0078] This invention also provides a method for preparing a flash stream, comprising:

[0079] Preparation of flash stream: The reaction products were flashed in multiple stages at 100-160℃ and 0.04-3 MPaG to obtain the flash stream.

[0080] Preferably, the flash stream includes recycled ethylene and product components.

[0081] The present invention also provides a method for separating product components, comprising:

[0082] The product components are fed into a solvent pre-separation column, where the overhead stream and bottom stream are separated. The overhead stream is then fed into a 1-hexene separation column, where the C6 component is separated at the top and the recycled solvent is separated at the bottom. The C6 component is fed into a C6 separation column, where 1-hexene is separated at the top and C6 byproducts, including methylcyclopentane and methylenecyclopentane, are separated at the bottom. The bottom stream is then fed into a solvent separation column, where the recycled solvent is separated at the top and the intermediate component is separated at the bottom. The intermediate component is then fed into a 1-octene light separation column, where 1-octene is separated at the top and the heavy component is separated at the bottom. Preferably, the solvent pre-separation column operates at a temperature of 100-200°C and a pressure of 0-0.2 MPaG.

[0083] Preferably, the operating temperature of the C6 separation tower is 70-170℃ and the operating pressure is 0-0.2MPaG.

[0084] Preferably, the operating temperature of the 1-hexene separation tower is 60-130℃ and the operating pressure is 0-0.2MPaG.

[0085] Preferably, the solvent separation tower operates at a temperature of 110-200℃ and an operating pressure of 0.1-0.3 MPaG.

[0086] Preferably, the operating temperature of the 1-octene light separation tower is 80-210℃ and the operating pressure is -0.1-0.1 MPaG.

[0087] Preferably, the stream drawn from the top of the solvent pre-separation tower contains more than 99 wt% of the C6 component and the lighter component C6- from the feed, and 10-90% of the total solvent component in the feed is drawn. The stream drawn from the bottom of the tower contains the solvent component remaining after the top of the tower, as well as more than 99 wt% of the C8 component and the heavier component C8+ from the feed.

[0088] The present invention also provides a method for separating product components, comprising:

[0089] The product components are fed into a 1-octene pre-separation column, where the top of the column is separated to obtain a pre-separation column overhead stream, and the bottom of the column is separated to obtain a bottom stream. The pre-separation column overhead stream is fed into a 1-octene heavy separation column, where the top of the column is separated to obtain a heavy separation column overhead stream, and the bottom of the column is separated to obtain 1-octene. The heavy separation column overhead stream is fed into a 1-hexene separation column, where the top of the column is separated to obtain a C6 component, and the bottom of the column is separated to obtain a recycled solvent. The C6 component is fed into a C6 separation column, where the top of the column is separated to obtain 1-hexene, and the bottom of the column is separated to obtain C6 byproducts, including methylcyclopentane and methylenecyclopentane. The bottom stream is fed into a de-heavy separation column, where the top of the column is separated to obtain 1-octene, and the bottom of the column is separated to obtain a heavy component.

[0090] Preferably, the operating temperature of the 1-octene pre-separation tower is 120-220℃ and the operating pressure is 0.1-0.3MPaG.

[0091] Preferably, the operating temperature of the 1-octene heavy separation tower is 100-190℃ and the operating pressure is 0.1-0.3MPaG.

[0092] Preferably, the operating temperature of the C6 separation tower is 70-170℃ and the operating pressure is 0-0.2MPaG.

[0093] Preferably, the operating temperature of the 1-hexene separation tower is 60-130℃ and the operating pressure is 0-0.2MPaG.

[0094] Preferably, the operating temperature of the deweight removal tower is 80-210℃ and the operating pressure is -0.1-0.1MPaG.

[0095] Preferably, the overhead stream of the 1-octene pre-separation column contains 99 wt% of the solvent, C6 component, and lighter component C6- from the feed, and 80% of the total C8 component from the feed. The reboiler stream contains the remaining C8 component after the overhead stream, and 99 wt% of the C10 and heavier component C10+ from the feed.

[0096] The present invention also provides a method for separating product components, comprising:

[0097] The product components are fed into a single-wall column. C6 linear α-olefins are separated at the top of the column, C6 by-products of α-olefins are separated on the first side, and recycled solvent is separated at the bottom of the column.

[0098] Preferably, the distillation temperature of the single-divided-wall column is 50-250℃ and the operating pressure is 0.01-0.3 MPaG.

[0099] Preferably, the C6 straight-chain α-olefin is 1-hexene.

[0100] Preferably, the C6 byproduct is one or more of methylcyclopentane, methylenecyclopentane, and internal olefins.

[0101] The present invention also provides a method for separating product components, comprising:

[0102] The product components are fed into partition column one. At the top of partition column one, C6 straight-chain α-olefins, α-olefin C6 byproducts, and solvent are separated. The product flows to partition column two. C8 straight-chain α-olefins are separated on the first side of partition column one, and C10 and above straight-chain α-olefins are separated at the bottom of partition column one. C6 straight-chain α-olefins are separated at the top of partition column two, and α-olefin C6 byproducts are produced on the first side of partition column two. Solvent is separated at the bottom of partition column two.

[0103] Preferably, the distillation temperature of the first distillation column is 50-300℃ and the operating pressure is -0.1-0.3 MPaG.

[0104] Preferably, the distillation temperature of the second distillation column is 50-250℃ and the operating pressure is 0.01-0.3 MPaG.

[0105] Preferably, the C6 straight-chain α-olefin is 1-hexene.

[0106] Preferably, the C6 byproducts are methylcyclopentane, methylenecyclopentane, and internal olefins.

[0107] Preferably, the C8 straight-chain α-olefin is 1-octene.

[0108] This invention also provides a method for preparing an amino-functionalized adsorbent material, comprising:

[0109] Graphene oxide was dispersed in Tris-hydrochloric acid buffer at pH 8.3-8.7 and sonicated for 1-3 hours. 3,4-Dihydroxyphenylacetamide was added, and the mixture was stirred at 25-35°C for 20-30 hours. After centrifugation at 7000-9000 rpm for 5-15 minutes, the mixture was washed with deionized water and freeze-dried at -45-55°C for 40-50 hours to obtain coated graphene. Glutaraldehyde was dissolved in deionized water to obtain a glutaraldehyde solution. The coated graphene was dispersed in deionized water to obtain a coated graphene dispersion. The glutaraldehyde solution was added, and the mixture was stirred at room temperature for 20-40 minutes. N-Isopropyl-1,3-diaminopropane was added, and the mixture was stirred at room temperature for 10-20 hours. After centrifugation at 7000-9000 rpm for 5-15 minutes, the mixture was washed with deionized water and freeze-dried at -45-55°C for 40-50 hours to obtain an amino-functionalized adsorbent material.

[0110] Preferably, the mass-to-volume ratio of graphene oxide to Tris-hydrochloric acid buffer is 2 mg: 0.5-2 mL.

[0111] Preferably, the mass ratio of graphene oxide to 3,4-dihydroxyphenylacetamide is 2:0.5-3.

[0112] Preferably, in the glutaraldehyde solution, the mass-to-volume ratio of glutaraldehyde to deionized water is 1:1-5.

[0113] Preferably, in the graphene-coated dispersion, the mass-to-volume ratio of coated graphene to deionized water is 3 mg: 1-5 mL.

[0114] Preferably, the mass of the glutaraldehyde solution is measured by the mass of glutaraldehyde therein, the mass of the coated graphene is measured by the mass of 3,4-dihydroxyphenylacetamide therein, and the mass ratio of 3,4-dihydroxyphenylacetamide to glutaraldehyde is 1:3-10.

[0115] Preferably, the mass of the graphene coating is measured by the mass of 3,4-dihydroxyphenylacetamide therein, and the mass ratio of 3,4-dihydroxyphenylacetamide to N-isopropyl-1,3-diaminopropane is 2:3-10.

[0116] More preferably, N-vinyl-N-methylacetamide can also be added to the graphene-coated dispersion.

[0117] More preferably, the mass of the coated graphene is measured by the mass of 3,4-dihydroxyphenylacetamide therein, and the mass ratio of 3,4-dihydroxyphenylacetamide to N-vinyl-N-methylacetamide is 2:0.5-5.

[0118] This invention also provides a method for preparing purified circulating solvent, comprising:

[0119] The separated circulating solvent was dispersed in deionized water to obtain a circulating solvent dispersion. Amino-functionalized adsorbent material was added, and the mixture was stirred at 35-45℃ and 100-300 rpm for 5-10 h. After centrifugation at 7000-9000 rpm for 5-15 min, the supernatant was collected, washed with deionized water, dried with anhydrous magnesium sulfate, and filtered to obtain the purified circulating solvent.

[0120] Preferably, in the circulating solvent dispersion, the volume ratio of circulating solvent to deionized water is 3:3-10.

[0121] Preferably, the volume-to-mass ratio of the circulating solvent to the amino-functionalized adsorbent is 1 mL: 0.1-0.5 mg.

[0122] Preferably, the volume-to-mass ratio of the circulating solvent to anhydrous magnesium sulfate is 1 mL: 1-5 mg.

[0123] This invention, by employing two differentiated distillation pathways and amino-functionalized adsorbents to purify circulating solvents, offers the following advantages: it overcomes the high energy consumption bottleneck of traditional fixed-sequence separation, reduces energy loss caused by repeated heating and cooling of the column and high reflux ratios, and significantly improves the recovery rate of circulating solvents; the amino-functionalized adsorbents can efficiently remove catalyst residues through the coordination of amino groups with transition metal ions, and the method is stable and controllable, suitable for continuous industrial production. Therefore, this invention is a low-energy-consumption, high-purification-efficiency method for separating solution polymerization products with clear industrial application value. Attached Figure Description

[0124] Figure 1 This is a flowchart of Example 1.

[0125] Figure 2 This is a schematic diagram of the separation unit process in Example 1.

[0126] Figure 3 This is a schematic diagram of the separation unit process in Example 2.

[0127] Figure 4 This is a schematic diagram of the separation unit process in Example 3.

[0128] Figure 5 This is a schematic diagram of the separation unit process in Example 4.

[0129] Figure 6 This is a schematic diagram of the separation unit process in Comparative Example 1. Detailed Implementation

[0130] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0131] The concepts involved in this application will first be described with reference to the accompanying drawings. It should be noted that the following descriptions of various concepts are only for the purpose of making the content of this application easier to understand and do not constitute a limitation on the scope of protection of this application; furthermore, the embodiments and features in the embodiments of this application can be combined with each other unless otherwise specified. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0132] Example 1:

[0133] The flowchart of Example 1 is as follows: Figure 1 As shown, the separation method for solution polymerization products includes a purification unit, a reaction unit, a flash evaporation unit, and a separation unit.

[0134] The separation method for solution polymerization reaction products includes: purifying the reaction raw materials through a purification unit to obtain purified reaction raw materials; carrying out a polymerization reaction between the purified reaction raw materials and a catalyst solution through a reaction unit to obtain reaction products; separating the reaction products through a flash evaporation unit to obtain flash streams, which include recycled solvent and product components; and separating the product components into different components through a separation unit.

[0135] The flow chart of the separation unit in Example 1 is as follows: Figure 2 As shown, the separation unit includes a solvent pre-separation tower, a 1-hexene separation tower, a C6 separation tower, a solvent separation tower, and a 1-octene light separation tower.

[0136] Preparation of refined reaction feedstock: The reaction feedstock includes solvent and ethylene. Fresh ethylene is transported into the boundary area via an external pipeline, heated to 90°C, and then fed from top to bottom into an ethylene deoxidizer for deoxygenation. It then flows from top to bottom into an ethylene carbon monoxide removal tower to remove carbon monoxide. Afterward, it enters an ethylene cooler to cool to 40°C, and then flows from top to bottom into an ethylene dryer / carbon dioxide remover to remove moisture and carbon dioxide, yielding refined ethylene. Fresh solvent is transported into the boundary area via an external pipeline. It passes through a coarse solvent coalescer to remove a large amount of water, and is then transported to a solvent degassing tower for light component removal. The bottom liquid enters a solvent cooler to cool to 40°C, and the solvent flows from bottom to top into a solvent dryer to remove moisture. After drying, the solvent flows from bottom to top into a solvent guard bed to remove other polar substances. After filtration through a solvent filter, refined solvent is obtained. The solvent is n-hexane.

[0137] Preparation of the catalyst solution: The catalyst was added to the purified solvent and stirred at 40℃ and 200 rpm for 30 min to obtain the catalyst solution. The catalyst includes ligand a, transition metal compound b, and activator c. Ligand a is 1,4-phenylenebis(diphenylphosphinemethylamine), transition metal compound b is zirconium tetrachloride, and activator c is methylaluminoxane. The molar ratio of ligand a to transition metal compound b is 2:1, and the molar ratio of ligand a to activator c is 1:100. The mass of the catalyst is measured by the mass of ligand a, and the mass-volume ratio of ligand a to the purified solvent is 20 g: 1 L.

[0138] Preparation of reaction products: Refined ethylene was pressurized to 4.0 MPaG using a fresh ethylene compressor and fed into the reaction unit reactor. Refined solvent was also pressurized to 4.0 MPaG and fed into the reaction unit reactor using a pump. Hydrogen was pressurized to 4.0 MPaG using a hydrogen compressor and fed into the reaction unit reactor. After mixing, the mixture entered the reactor feed cooler, where it was cooled and the outlet temperature was controlled at 20°C before entering the first reactor. The catalyst solution was pressurized to 4.0 MPaG and fed into the first reactor. The mixture was held in the reactor at 80°C and 4.0 MPaG for 40 minutes, then transferred to a termination reactor. A terminator was added to terminate the reaction, yielding the reaction products. The volume ratio of refined solvent to refined ethylene was 2 L: 1 m³. 3 The volume ratio of the purified solvent to the catalyst solution was 2L:1mL, and the terminator was isooctanol, with a volume ratio of 2L:1mL.

[0139] Preparation of flash stream: The reaction products were flashed in multiple stages at 130°C and 1.0 MPaG to obtain the flash stream, which included recycled ethylene and product components.

[0140] Separation of product components: The product components are fed into a solvent pre-separation column, where the overhead stream is separated and the bottom stream is separated; the overhead stream is fed into a 1-hexene separation column, where the C6 component is separated and the recycled solvent is separated; the C6 component is fed into a C6 separation column, where 1-hexene is separated at the top and C6 by-products, including methylcyclopentane and methylenecyclopentane, are separated; the bottom stream is fed into a solvent separation column, where the recycled solvent is separated at the top and the intermediate component is separated at the bottom; the intermediate component is fed into a 1-octene light separation column, where 1-octene is separated at the top and the heavy component is separated at the bottom. The solvent pre-separation tower operates at a temperature of 150℃ and a pressure of 0.1 MPaG; the 1-hexene separation tower operates at a temperature of 120℃ and a pressure of 0.2 MPaG; the C6 separation tower operates at a temperature of 105℃ and a pressure of 0.2 MPaG; the solvent separation tower operates at a temperature of 180℃ and a pressure of 0.2 MPaG; the 1-octene separation tower operates at a temperature of 190℃ and a pressure of 0.05 MPaG. The stream collected from the top of the solvent pre-separation tower contains 99 wt% of the C6 component and the lighter component C6- from the feed, and 80% of the total solvent component in the feed is collected. The stream collected from the bottom of the tower contains the remaining solvent component after the top collection, as well as 99 wt% of the C8 component and the heavier component C8+ from the feed.

[0141] Example 2: The only difference between this example and Example 1 is the separation of the product components.

[0142] The flow chart of the separation unit in Example 2 is as follows: Figure 3As shown, the separation unit includes a 1-octene pre-separation tower, a 1-octene heavy separation tower, a hexene heavy separation tower, and a de-heavy separation tower.

[0143] Separation of product components: The product components are fed into a 1-octene pre-separation column, where the top of the column is separated to obtain the pre-separation column overhead stream, and the bottom of the column is separated to obtain the bottom stream; the pre-separation column overhead stream is fed into a 1-octene heavy separation column, where the top of the column is separated to obtain the heavy separation column overhead stream, and the bottom of the column is separated to obtain 1-octene; the heavy separation column overhead stream is fed into a 1-hexene separation column, where the top of the column is separated to obtain the C6 component, and the bottom of the column is separated to obtain the recycled solvent; the C6 component is fed into a C6 separation column, where the top of the column is separated to obtain 1-hexene, and the bottom of the column is separated to obtain the C6 byproduct, which includes methylcyclopentane and methylenecyclopentane; the bottom stream is fed into a de-heavy separation column, where the top of the column is separated to obtain 1-octene, and the bottom of the column is separated to obtain the heavy component. The operating temperature of the 1-octene pre-separation tower is 190℃, and the operating pressure is 0.2 MPaG; the operating temperature of the 1-octene separation tower is 150℃, and the operating pressure is 0.2 MPaG; the operating temperature of the 1-hexene separation tower is 120℃, and the operating pressure is 0.1 MPaG; the operating temperature of the C6 separation tower is 105℃, and the operating pressure is 0.2 MPaG; the operating temperature of the heavy component removal tower is 180℃, and the operating pressure is 0.1 MPaG; the stream collected from the top of the 1-octene pre-separation tower contains 99 wt% of the solvent, lighter C6 components, and C6- from the feed, and 80% of the total C8 components from the feed is collected; the stream collected from the bottom of the tower contains the remaining C8 components after the top collection, and 99 wt% of the C10 and heavier C10+ components from the feed.

[0144] Example 3: The only difference between this example and Example 1 is the separation of the product components.

[0145] The flow chart of the separation unit in Example 3 is as follows: Figure 4 As shown, the separation unit includes a single-walled tower.

[0146] Product component separation: The product components are fed into a single-divided-wall column. C6 straight-chain α-olefins are separated at the top of the column, C6 byproducts of α-olefins are separated on the first side, and recycled solvent is separated at the bottom. The single-divided-wall column has a distillation temperature of 180℃ and an operating pressure of 0.1 MPaG. The C6 straight-chain α-olefin is 1-hexene, and the C6 byproducts are methylcyclopentane and methylenecyclopentane.

[0147] Example 4: The only difference between this example and Example 1 is the separation of the product components.

[0148] The flow chart of the separation unit in Example 4 is as follows: Figure 5 As shown, the separation unit includes a double-walled tower, which includes a first partition tower and a second partition tower.

[0149] Product component separation: The product components are fed into partition column one. The top of partition column one yields C6 straight-chain α-olefins, C6 α-olefin byproducts, and solvent. The overhead stream flows to partition column two. The first side of partition column one yields C8 straight-chain α-olefins, and the bottom of partition column one yields C10 and above straight-chain α-olefins. The top of partition column two yields C6 straight-chain α-olefins, the first side of partition column two produces C6 α-olefin byproducts, and the bottom of partition column two yields solvent. The rectification temperature of partition column one is 250℃, and the operating pressure is 0.1 MPaG; the rectification temperature of partition column two is 180℃, and the operating pressure is 0.1 MPaG. The C6 straight-chain α-olefin is 1-hexene, and the C6 byproducts are methylcyclopentane and methylenecyclopentane; the C8 straight-chain α-olefin is 1-octene.

[0150] Example 5: This example differs from Example 1 only in that it also includes the preparation of purified circulating solvent.

[0151] Preparation of amino-functionalized adsorbent material: Graphene oxide was dispersed in Tris-hydrochloric acid buffer at pH 8.5, sonicated for 2 h, 3,4-dihydroxyphenylacetamide was added, stirred at 30 °C for 24 h, centrifuged at 8000 rpm for 10 min, washed with deionized water, and freeze-dried at -50 °C for 48 h to obtain coated graphene; glutaraldehyde was dissolved in deionized water to obtain glutaraldehyde solution; coated graphene was dispersed in deionized water to obtain coated graphene dispersion, glutaraldehyde solution was added, stirred at room temperature for 30 min, N-isopropyl-1,3-diaminopropane was added, stirred at room temperature for 18 h, centrifuged at 8000 rpm for 10 min, washed with deionized water, and freeze-dried at -50 °C for 48 h to obtain amino-functionalized adsorbent material. The mass-to-volume ratio of graphene oxide to Tris-hydrochloric acid buffer was 2 mg:1 mL, and the mass ratio of graphene oxide to 3,4-dihydroxyphenylacetamide was 2:1; in the glutaraldehyde solution, the mass-to-volume ratio of glutaraldehyde to deionized water was 1:3; in the coated graphene dispersion, the mass-to-volume ratio of coated graphene to deionized water was 3 mg:2 mL; the mass of the glutaraldehyde solution was measured by the mass of glutaraldehyde contained therein, and the mass of the coated graphene was measured by the mass of 3,4-dihydroxyphenylacetamide contained therein, with a mass ratio of 3,4-dihydroxyphenylacetamide to glutaraldehyde of 1:5, and a mass ratio of 3,4-dihydroxyphenylacetamide to N-isopropyl-1,3-diaminopropane of 2:5.

[0152] Preparation of purified circulating solvent: The separated circulating solvent was dispersed in deionized water to obtain a circulating solvent dispersion. Amino-functionalized adsorbent material was added, and the mixture was stirred at 40℃ and 200 rpm for 8 h. After centrifugation at 8000 rpm for 10 min, the supernatant was collected, washed with deionized water, dried with anhydrous magnesium sulfate, and filtered to obtain the purified circulating solvent. In the circulating solvent dispersion, the volume ratio of circulating solvent to deionized water was 3:5; the volume-to-mass ratio of circulating solvent to amino-functionalized adsorbent material was 1 mL:0.3 mg; and the volume-to-mass ratio of circulating solvent to anhydrous magnesium sulfate was 1 mL:2 mg.

[0153] Example 6: The only difference between this example and Example 5 is the preparation of the amino-functionalized adsorbent material.

[0154] Preparation of amino-functionalized adsorbent material: Graphene oxide was dispersed in Tris-hydrochloric acid buffer at pH 8.5, sonicated for 2 h, 3,4-dihydroxyphenylacetamide was added, stirred at 30 °C for 24 h, centrifuged at 8000 rpm for 10 min, washed with deionized water, and freeze-dried at -50 °C for 48 h to obtain coated graphene; glutaraldehyde was dissolved in deionized water to obtain glutaraldehyde solution; coated graphene was dispersed in deionized water to obtain coated graphene dispersion, glutaraldehyde solution was added, stirred at room temperature for 30 min, N-isopropyl-1,3-diaminopropane was added, stirred at room temperature for 18 h, centrifuged at 8000 rpm for 10 min, washed with deionized water, and freeze-dried at -50 °C for 48 h to obtain amino-functionalized adsorbent material. The mass-to-volume ratio of graphene oxide to Tris-hydrochloric acid buffer was 2 mg:1 mL, and the mass ratio of graphene oxide to 3,4-dihydroxyphenylacetamide was 1:1; in the glutaraldehyde solution, the mass-to-volume ratio of glutaraldehyde to deionized water was 1:3; in the coated graphene dispersion, the mass-to-volume ratio of coated graphene to deionized water was 3 mg:2 mL; the mass of the glutaraldehyde solution was measured by the mass of glutaraldehyde contained therein, and the mass of the coated graphene was measured by the mass of 3,4-dihydroxyphenylacetamide contained therein, with the mass ratio of 3,4-dihydroxyphenylacetamide to glutaraldehyde being 1:5, and the mass ratio of 3,4-dihydroxyphenylacetamide to N-isopropyl-1,3-diaminopropane being 2:5.

[0155] Example 7: The only difference between this example and Example 5 is the preparation of the amino-functionalized adsorbent material.

[0156] Preparation of amino-functionalized adsorbent material: Graphene oxide was dispersed in Tris-hydrochloric acid buffer at pH 8.5, sonicated for 2 h, 3,4-dihydroxyphenylacetamide was added, stirred at 30 °C for 24 h, centrifuged at 8000 rpm for 10 min, washed with deionized water, and freeze-dried at -50 °C for 48 h to obtain coated graphene; glutaraldehyde was dissolved in deionized water to obtain glutaraldehyde solution; coated graphene was dispersed in deionized water to obtain coated graphene dispersion, glutaraldehyde solution was added, stirred at room temperature for 30 min, N-isopropyl-1,3-diaminopropane and N-vinyl-N-methylacetamide were added, stirred at room temperature for 18 h, centrifuged at 8000 rpm for 10 min, washed with deionized water, and freeze-dried at -50 °C for 48 h to obtain amino-functionalized adsorbent material. The mass-to-volume ratio of graphene oxide to Tris-hydrochloric acid buffer was 2 mg:1 mL, and the mass ratio of graphene oxide to 3,4-dihydroxyphenylacetamide was 2:1. In the glutaraldehyde solution, the mass-to-volume ratio of glutaraldehyde to deionized water was 1:3. In the coated graphene dispersion, the mass-to-volume ratio of coated graphene to deionized water was 3 mg:2 mL. The mass of the glutaraldehyde solution was measured by the mass of glutaraldehyde contained therein, and the mass of the coated graphene was measured by the mass of 3,4-dihydroxyphenylacetamide contained therein. The mass ratio of 3,4-dihydroxyphenylacetamide to glutaraldehyde was 1:5, the mass ratio of 3,4-dihydroxyphenylacetamide to N-isopropyl-1,3-diaminopropane was 2:5, and the mass ratio of 3,4-dihydroxyphenylacetamide to N-vinyl-N-methylacetamide was 2:1.

[0157] Example 8: The only difference between this example and Example 5 is the preparation of the amino-functionalized adsorbent material.

[0158] Preparation of amino-functionalized adsorbent material: Graphene oxide was dispersed in Tris-hydrochloric acid buffer at pH 8.5, sonicated for 2 h, 3,4-dihydroxyphenylacetamide was added, stirred at 30 °C for 24 h, centrifuged at 8000 rpm for 10 min, washed with deionized water, and freeze-dried at -50 °C for 48 h to obtain coated graphene; glutaraldehyde was dissolved in deionized water to obtain glutaraldehyde solution; coated graphene was dispersed in deionized water to obtain coated graphene dispersion, glutaraldehyde solution was added, stirred at room temperature for 30 min, N-isopropyl-1,3-diaminopropane and N-vinyl-N-methylacetamide were added, stirred at room temperature for 18 h, centrifuged at 8000 rpm for 10 min, washed with deionized water, and freeze-dried at -50 °C for 48 h to obtain amino-functionalized adsorbent material. The mass-to-volume ratio of graphene oxide to Tris-hydrochloric acid buffer was 2 mg:1 mL, and the mass ratio of graphene oxide to 3,4-dihydroxyphenylacetamide was 2:1. In the glutaraldehyde solution, the mass-to-volume ratio of glutaraldehyde to deionized water was 1:3. In the coated graphene dispersion, the mass-to-volume ratio of coated graphene to deionized water was 3 mg:2 mL. The mass of the glutaraldehyde solution was measured by the mass of glutaraldehyde contained therein, and the mass of the coated graphene was measured by the mass of 3,4-dihydroxyphenylacetamide contained therein. The mass ratio of 3,4-dihydroxyphenylacetamide to glutaraldehyde was 1:5, the mass ratio of 3,4-dihydroxyphenylacetamide to N-isopropyl-1,3-diaminopropane was 2:5, and the mass ratio of 3,4-dihydroxyphenylacetamide to N-vinyl-N-methylacetamide was 1:1.

[0159] Comparative Example 1: The only difference between this comparative example and Example 1 is the separation of the product components.

[0160] The flow chart of the separation unit in Comparative Example 1 is shown below. Figure 6 As shown, the separation unit includes a heavy removal tower, a solvent separation tower, a 1-hexene separation tower, and a 1-octene separation tower.

[0161] Product component separation: The product components are fed into a heavy-duty separation column, where intermediate components are separated at the top and heavy components are separated at the bottom. The intermediate components are then fed into a solvent separation column, where overhead streams and bottom streams are separated. The overhead stream is fed into a 1-hexene separation column, where 1-hexene is separated at the top and C6 byproducts are separated at the bottom. The bottom stream is fed into a 1-octene separation column, where recycled solvent is separated at the top and 1-octene is separated at the bottom. The operating temperature of the heavy-duty separation column is 180℃ and the operating pressure is 0.1 MPaG; the operating temperature of the solvent separation column is 190℃ and the operating pressure is 0.2 MPaG; the operating temperature of the 1-hexene separation column is 120℃ and the operating pressure is 0.1 MPaG; and the operating temperature of the 1-octene separation column is 150℃ and the operating pressure is 0.2 MPaG.

[0162] Comparative Example 2: The only difference between this comparative example and Example 5 is the preparation of the amino-functionalized adsorbent material.

[0163] Preparation of amino-functionalized adsorbent material: Graphene oxide was dispersed in Tris-hydrochloric acid buffer at pH 8.5, sonicated for 2 h, and 3,4-dihydroxyphenylacetamide was added. The mixture was stirred at 30 °C for 24 h, centrifuged at 8000 rpm for 10 min, washed with deionized water, and freeze-dried at -50 °C for 48 h to obtain coated graphene, i.e., amino-functionalized adsorbent material. The mass-to-volume ratio of graphene oxide to Tris-hydrochloric acid buffer was 2 mg:1 mL, and the mass ratio of graphene oxide to 3,4-dihydroxyphenylacetamide was 2:1.

[0164] Comparative Example 3: The only difference between this comparative example and Example 5 is the preparation of the amino-functionalized adsorbent material.

[0165] Preparation of amino-functionalized adsorbent material: Glutaraldehyde was dissolved in deionized water to obtain a glutaraldehyde solution; graphene oxide was dispersed in Tris-hydrochloric acid buffer at pH 8.5 to obtain a graphene dispersion; the glutaraldehyde solution was added, and the mixture was stirred at room temperature for 30 min; N-isopropyl-1,3-diaminopropane was added, and the mixture was stirred at room temperature for 18 h; the mixture was centrifuged at 8000 rpm for 10 min, washed with deionized water, and freeze-dried at -50℃ for 48 h to obtain the amino-functionalized adsorbent material. In the glutaraldehyde solution, the mass-to-volume ratio of glutaraldehyde to deionized water was 1:3; in the graphene dispersion, the mass-to-volume ratio of graphene oxide to Tris-hydrochloric acid buffer was 2 mg:1 mL; the mass of the glutaraldehyde solution was measured by the mass of glutaraldehyde contained therein; the mass ratio of graphene oxide to glutaraldehyde was 2:5; and the mass ratio of graphene oxide to N-isopropyl-1,3-diaminopropane was 4:5.

[0166] Comparative Example 4: The only difference between this comparative example and Example 5 is the preparation of the purified circulating solvent.

[0167] Preparation of purified circulating solvent: The separated circulating solvent was dispersed in deionized water to obtain a circulating solvent dispersion. Graphene oxide was added, and the mixture was stirred at 40℃ and 200 rpm for 8 h. After centrifugation at 8000 rpm for 10 min, the supernatant was collected, washed with deionized water, dried with anhydrous magnesium sulfate, and filtered to obtain the purified circulating solvent. In the circulating solvent dispersion, the volume ratio of circulating solvent to deionized water was 3:5; the volume-to-mass ratio of circulating solvent to graphene oxide was 1 mL:0.3 mg; and the volume-to-mass ratio of circulating solvent to anhydrous magnesium sulfate was 1 mL:2 mg.

[0168] Experimental Example 1: Test of the purity of the separated product components.

[0169] Test samples: Separation of product components in Examples 1-2.

[0170] Test method: Gas chromatography was used to test the purity of the products separated from the top and bottom of different separation columns. A flame ionization detector and an HP-5 capillary column were used. The temperature program included 40℃ for 3 min, increasing the temperature to 200℃ at 10℃ / min and holding for 3 min. Nitrogen was used as the carrier gas, the flow rate was 1 mL / min, the injection volume was 5 μL, and the split ratio was 50:1.

[0171] In Example 1, the solvent pre-separation tower exhibits precise ability to separate light and heavy components. At the top of the tower, it can efficiently enrich over 99 wt% of the C6 component and the lighter C6- component from the feed, while precisely controlling 10%-90% of the solvent to be collected with the light components, preventing light components from remaining in the heavy phase at the bottom of the tower. At the bottom of the tower, it can retain over 99 wt% of the C8 component and the heavier components, while removing the C6 component and the lighter C6- component, thus avoiding interference from the light components to the subsequent separation of the C8 component. The subsequent 1-hexene separation tower can further achieve deep separation of the light components, with the C6 and lower C6 components at the top of the tower being pure. The purity reaches over 99%, ensuring the high-purity recovery of methylcyclopentane, methylenecyclopentane, and 1-hexene; the solvent purity in the bottom of the column simultaneously reaches over 99%, directly meeting the requirements for recycling; the top of the solvent separation column can recover circulating solvent with a purity of over 99%, while the bottom of the column is enriched with over 99% of C8 and heavier components; the top of the 1-octene light separation column has a 1-octene purity of over 99%, and the bottom of the column also has a C10 and heavier component purity of over 99%, achieving complete separation of the target product and heavy components, effectively solving the problems of component cross-contamination and solvent entrainment in traditional sequential separation.

[0172] In Example 2, the 1-octene pre-separation tower exhibits excellent separation performance between intermediate and heavy components. Over 99 wt% of solvent and the lighter component C6- can be collected from the top of the tower, while 10%-90% of the C8 component is controlled to be collected with the intermediate components, preventing solvent residue in the heavy phase at the bottom of the tower. The bottom of the tower retains over 99 wt% of C10 and the heavier components, and is free of solvent and the lighter component C6-, eliminating contamination of the C8 component by the heavy components. The de-heavy component tower can accurately separate the C8 component from the heavy components, with 1-octene purity exceeding 99% at the top and C10 and the heavier components exceeding 99% purity at the bottom, ensuring complete removal of the heavy components. The 1-octene heavy separation tower and the 1-hexene separation tower further achieve refined component separation. The top of the 1-octene heavy separation tower can recover more than 99% of C4, C6 and solvent mixture, while the purity of 1-octene in the bottom of the tower remains above 99%. The top of the 1-hexene separation tower has a purity of more than 99% for C4 and C6 components, and the purity of the solvent in the bottom of the tower exceeds 99%, thus achieving high-purity recovery of each target component and recycling of the solvent.

[0173] Experimental Example 2: Energy consumption test of the separation unit.

[0174] Test samples: Separation units of Examples 1-4 and Comparative Example 1.

[0175] Test Method: Each separation unit was built and debugged to a stable operating state according to the process of the corresponding embodiment or comparative example. The feed components and feed flow of each separation unit were controlled to be consistent with the actual industrial production conditions, and the operating temperature and operating pressure of each separation tower strictly followed the parameters set in the corresponding embodiment or comparative example. A high-precision calorimeter was used to monitor the cold load QC and heat load QR of each separation tower in real time. The cold load and heat load data of each tower were continuously recorded for 24 hours of stable operation. The average cold load and average heat load of each separation tower during this period were calculated. The average cold load of all separation towers in the same separation unit were added together to obtain the total cold load of the unit, and the average heat load was added together to obtain the total heat load of the unit. The cold load is represented by a negative value to indicate the heat that the system needs to remove, and the heat load is represented by a positive value to indicate the heat that the system needs to input.

[0176] The energy consumption test results of the separation unit in Example 1 are shown in Table 1, the energy consumption test results of the separation unit in Example 2 are shown in Table 2, the energy consumption test results of the separation unit in Example 3 are shown in Table 3, the energy consumption test results of the separation unit in Example 4 are shown in Table 4, and the energy consumption test results of the separation unit in Comparative Example 1 are shown in Table 5.

[0177] Table 1. Energy consumption test results of the separation unit in Example 1

[0178]

[0179] Table 2. Energy consumption test results of the separation unit in Example 2

[0180]

[0181] Table 3. Energy consumption test results of the separation unit in Example 3

[0182]

[0183] Table 4. Energy consumption test results of the separation unit in Example 4

[0184]

[0185] Table 5 Energy consumption test results of the separation unit in Comparative Example 1

[0186]

[0187] Comparative Example 1, using a traditional sequential separation unit, has a total cooling load of -7065kW and a total heat load of 6353kW, significantly higher energy consumption than the separation units in Examples 1-4 of this invention. Example 1 has a total cooling load of -6318kW and a total heat load of 5974kW, while Example 2 has a total cooling load of -6327kW and a total heat load of 6141kW. Both examples, through differentiated distillation paths, overcome the limitations of traditional fixed-sequential separation, reducing energy losses caused by repeated heating and cooling of the column and high reflux ratios. Therefore, their energy consumption is significantly lower than that of the comparative example. 1. Significantly reduced; Example 3, using a single-walled tower, has a total cooling load of only -1556kW and a total heat load of 2362kW. Example 4, using a double-walled tower, has a total cooling load of -5652kW and a total heat load of 5400kW. Example 3 has the lowest energy consumption because the walled tower integrates the separation function of multiple towers, which greatly reduces the number of towers and the loss in the energy transfer process. This further verifies the significant advantage of the separation unit of the present invention in reducing energy consumption. In particular, the application of the walled tower structure can optimize energy utilization efficiency to the greatest extent.

[0188] Experimental Example 3: Adsorption capacity test of adsorption materials.

[0189] Test samples: amino-functionalized adsorbent materials or graphene oxide prepared in Examples 5-8 and Comparative Examples 2-4.

[0190] Test method: Prepare a Zr-containing solution with an initial concentration of 10 μg / L. 4+ For the circulating solvent test solution, 10 μg of amino-functionalized adsorbent or graphene oxide was added to 20 mL of circulating solvent test solution. The mixture was shaken and adsorbed at 40 °C and 200 rpm for 8 h. The mixture was then centrifuged at 8000 rpm for 10 min. The supernatant was filtered through a 0.22 μm organic filter membrane, and the Zr content in the supernatant was determined using inductively coupled plasma mass spectrometry. 4+ The equilibrium concentration. According to the formula Q(mg / g) = (C0 - C... e The adsorption capacity is calculated as Q × V / m, where Q is the adsorption capacity and C0 is the Zr content. 4+ The initial concentration is V, the volume of the test liquid is V, and the mass of the adsorbent material is m.

[0191] The adsorption capacity test results of the adsorption material prepared by this invention are shown in Table 6.

[0192] Table 6. Adsorption capacity test results of adsorption materials

[0193]

[0194] The amino-functionalized adsorbent materials prepared in Examples 5-8, after a complete amino-functionalization modification process, exhibited significantly higher adsorption capacities than the graphene oxide in Comparative Example 3. Example 5 achieved sufficient coating of graphene oxide with 3,4-dihydroxyphenylacetamide to optimize the material matrix structure. By cross-grafting N-isopropyl-1,3-diaminopropane with glutaraldehyde, a large number of amino active sites capable of specifically adsorbing target impurities were formed, and the material exhibited good dispersibility, facilitating impurity contact with the adsorption sites. Example 6 increased the amount of 3,4-dihydroxyphenylacetamide to more fully coat graphene oxide and construct a superior matrix structure, providing a foundation for subsequent amino grafting. With more attachment sites, the adsorption capacity was improved compared to Example 3; Example 7 introduced N-vinyl-N-methylacetamide, which further increased the number of amino functional sites and improved the dispersion stability of the material in the circulating solvent system, and the adsorption capacity was further improved; Example 8 increased the amount of N-vinyl-N-methylacetamide, making its adsorption sites more abundant and the adsorption capacity reached the highest level; Comparative Example 2 did not perform glutaraldehyde crosslinking and amino grafting, and Comparative Example 3 did not use 3,4-dihydroxyphenylacetamide to coat graphene oxide, but directly modified the original graphene oxide with amino groups, resulting in poor material structural integrity and lower adsorption capacity than Example 1.

[0195] Experimental Example 4: Purity test of purified circulating solvent.

[0196] Test samples: purified circulating solvents prepared in Examples 5-8 and Comparative Examples 2-4.

[0197] Test method: 1 mL of purified circulating solvent was diluted to 10 mL with anhydrous ethanol to obtain the sample test solution. After standing for 5 min, the solution was filtered through a 0.22 μm organic filter membrane to remove minor impurities. Purity was determined by gas chromatography using an HP-5 capillary column (30 m × 0.32 mm × 0.25 μm) and a flame ionization detector. The injection port temperature was set to 250 °C, the detector temperature to 300 °C, and the carrier gas was high-purity nitrogen at a flow rate of 1 mL / min. The temperature program was as follows: initial temperature 40 °C, maintained for 3 min, followed by increasing to 200 °C at a rate of 10 °C / min and maintaining for 5 min. The injection volume was 1 μL, and the split ratio was 50:1. Each sample was injected three times consecutively, and the mass fraction of the circulating solvent was calculated using the peak area normalization method.

[0198] The purity test results of the purified circulating solvent prepared in this invention are shown in Table 7.

[0199] Table 7. Purity test results of purified 1-octene

[0200]

[0201] Example 5 utilizes 3,4-dihydroxyphenylacetamide to fully coat graphene oxide, optimizing the matrix structure. N-isopropyl-1,3-diaminopropane is grafted onto the graphene oxide using glutaraldehyde, forming numerous amino active sites that specifically adsorb residual impurities after distillation. The material exhibits good dispersibility in the circulating solvent system, facilitating thorough contact between impurities and adsorption sites, resulting in excellent impurity removal and high purity. Example 6 increases the amount of 3,4-dihydroxyphenylacetamide, further coating graphene oxide to construct a superior matrix structure, providing more attachment sites for subsequent amino grafting. This increases the number of amino active sites, enhances impurity removal capability, and improves purity compared to Example 3. Example 7 introduces N-vinyl-N-methylacetamide during the preparation of the adsorbent material. This substance further increases the number of amino functional sites and improves the dispersion stability of the material in the circulating solvent system. The contact efficiency between impurities and adsorption sites is further improved, and purity is higher than in Example 4. The improvements were as follows: Example 8 increased the amount of N-vinyl-N-methylacetamide, resulting in richer amino functional sites on the surface of the adsorbent material, better material dispersion, and optimal adsorption and removal of impurities, thus achieving the highest purity among all samples. Comparative Example 2 did not perform glutaraldehyde crosslinking and amino grafting when preparing the adsorbent material; it only coated graphene oxide with 3,4-dihydroxyphenylacetamide. The material surface lacked specific amino active sites for adsorbing impurities, resulting in limited impurity removal and lower purity than Example 3. Comparative Example 3 did not use 3,4-dihydroxyphenylacetamide to coat graphene oxide; it directly modified the original graphene oxide with amino groups, resulting in poor material structural integrity, uneven distribution and limited number of amino active sites, and even worse impurity removal than Comparative Example 1, further reducing purity. Comparative Example 4 directly used original graphene oxide without any functional modification. Although it removed impurities solely through physical adsorption, it lacked specific active sites and had the lowest purity.

[0202] The embodiments and / or implementation methods described above are merely preferred embodiments and / or implementation methods for implementing the technology of the present invention, and are not intended to limit the implementation methods of the technology of the present invention in any way. Any person skilled in the art can make some modifications or alterations to other equivalent embodiments without departing from the scope of the technical means disclosed in the content of the present invention, but they should still be regarded as the technology or embodiments that are substantially the same as the present invention.

[0203] This document uses specific examples to illustrate the principles and implementation methods of this application. The descriptions of the above embodiments are only for the purpose of helping to understand the methods and core ideas of this application. The above descriptions are only preferred embodiments of this application. It should be noted that due to the limitations of written expression, while there are objectively infinite specific structures, those skilled in the art can make several improvements, modifications, or changes without departing from the principles of this application, and can also combine the above technical features in an appropriate manner. These improvements, modifications, changes, or combinations, or the direct application of the inventive concept and technical solution to other situations without modification, should all be considered within the scope of protection of this application.

Claims

1. A method for separating products from solution polymerization reactions, characterized in that: The separation method includes separation via distillation path or separation via partitioned column integration. The separation via distillation path includes solvent pre-separation or 1-octene pre-separation. The separation via partitioned column integration includes separation via single partitioned column or separation via double partitioned column. The solvent pre-separation scheme includes a solvent pre-separation tower, a C6 separation tower, a 1-hexene separation tower, a solvent separation tower, and a 1-octene light separation tower; the 1-octene pre-separation scheme includes a 1-octene pre-separation tower, a 1-octene heavy separation tower, a C6 separation tower, a 1-hexene separation tower, and a heavy separation tower. The separation products of the separation method include C6 byproducts, 1-hexene, 1-octene, recycled solvent, and heavy components, wherein the C6 byproducts include methylcyclopentane and methylenecyclopentane; The circulating solvent is purified using an amino-functionalized adsorbent to obtain a purified circulating solvent; The preparation method of the amino-functionalized adsorbent material includes dispersing graphene oxide in Tris-hydrochloric acid buffer at pH 8.3-8.7, sonicating for 1-3 hours, adding 3,4-dihydroxyphenylacetamide, stirring at 25-35°C for 20-30 hours, centrifuging at 7000-9000 rpm for 5-15 minutes, washing with deionized water, and freeze-drying at -45--55°C for 40-50 hours to obtain coated graphene; dissolving glutaraldehyde in deionized water... Glutaraldehyde solution was obtained by dispersing coated graphene in deionized water; the coated graphene dispersion was obtained by dispersing the graphene in deionized water, glutaraldehyde solution was added, and the mixture was stirred at room temperature for 20-40 min. N-isopropyl-1,3-diaminopropane was added, and the mixture was stirred at room temperature for 10-20 h. The mixture was centrifuged at 7000-9000 rpm for 5-15 min, washed with deionized water, and freeze-dried at -45--55℃ for 40-50 h to obtain amino-functionalized adsorbent material. The mass ratio of graphene oxide to 3,4-dihydroxyphenylacetamide is 2:0.5-3, and the mass ratio of 3,4-dihydroxyphenylacetamide to N-isopropyl-1,3-diaminopropane is 2:0.5-5.

2. The method for separating solution polymerization products according to claim 1, characterized in that: The solvent pre-separation tower operates at a temperature of 100-200℃ and a pressure of 0-0.2 MPaG; the C6 separation tower operates at a temperature of 70-170℃ and a pressure of 0-0.2 MPaG; the 1-hexene separation tower operates at a temperature of 60-130℃ and a pressure of 0-0.2 MPaG; the solvent separation tower operates at a temperature of 110-200℃ and a pressure of 0.1-0.3 MPaG; the 1-octene light separation tower operates at a temperature of 80-210℃ and a pressure of -0.1-0.1 MPaG; the stream collected from the top of the solvent pre-separation tower contains more than 99 wt% of the C6 component and the lighter component C6- from the feed, and 10-90 wt% of the total solvent component from the feed is collected; the stream collected from the bottom of the tower contains the remaining solvent component after the top collection, as well as more than 99 wt% of the 1-octene and heavy components from the feed.

3. The method for separating solution polymerization products according to claim 1, characterized in that: The operating temperature of the 1-octene pre-separation tower is 120-220℃, and the operating pressure is 0.1-0.3 MPaG; the operating temperature of the 1-octene heavy separation tower is 100-190℃, and the operating pressure is 0.1-0.3 MPaG; the operating temperature of the C6 separation tower is 70-170℃, and the operating pressure is 0-0.2 MPaG; the operating temperature of the 1-hexene separation tower is 60-130℃, and the operating pressure is 0-0.2 MPaG; the operating temperature of the heavy separation tower is 80-210℃, and the operating pressure is -0.1-0.1 MPaG; the stream collected from the top of the 1-octene pre-separation tower contains more than 99 wt% of the solvent, C6 component and lighter component C6- from the feed, and 10-90 wt% of the total 1-octene component from the feed is collected; the stream collected from the bottom of the tower contains the remaining 1-octene component after the top collection, and more than 99 wt% of the heavy components from the feed.

4. The method for separating solution polymerization products according to claim 1, characterized in that: In the solvent pre-separation, the overhead stream of the solvent pre-separation tower is separated, and the bottom stream of the solvent pre-separation tower is separated; the overhead stream of the solvent pre-separation tower enters the 1-hexene separation tower, the C6 component is separated at the top of the 1-hexene separation tower, and the recycled solvent is separated at the bottom of the 1-hexene separation tower. The C6 component enters a C6 separation column, where 1-hexene is separated at the top and C6 by-products, including methylcyclopentane and methylenecyclopentane, are separated at the bottom. The bottom stream of the solvent pre-separation column enters a solvent separation column, where recycled solvent is separated at the top and intermediate components are separated at the bottom. The intermediate components enter a 1-octene light separation column, where 1-octene is separated at the top and heavy components are separated at the bottom.

5. The method for separating solution polymerization products according to claim 1, characterized in that: In the 1-octene pre-separation, the top of the 1-octene pre-separation tower yields a pre-separation tower overhead stream, and the bottom of the 1-octene pre-separation tower yields a tower bottom stream; the pre-separation tower overhead stream enters a 1-octene heavy separation tower, the top of the 1-octene heavy separation tower yields a heavy separation tower overhead stream, and the bottom of the 1-octene heavy separation tower yields 1-octene; the heavy separation tower overhead stream enters a 1-hexene separation tower, the top of the 1-hexene separation tower yields a C6 component, and the bottom of the 1-hexene separation tower yields a recycled solvent; The C6 component enters the C6 separation column, where 1-hexene is separated at the top and C6 by-products, including methylcyclopentane and methylenecyclopentane, are separated at the bottom. The bottom stream of the 1-octene pre-separation column enters the deweighting column, where 1-octene is separated at the top and heavy components are separated at the bottom.

6. The method for separating solution polymerization products according to claim 1, characterized in that: The single-partitioned column separates 1-hexene at the top, C6 by-products from the side stream, and recycled solvent from the bottom. The distillation temperature of the single-partitioned column is 50-250℃, and the operating pressure is 0-0.3 MPaG. The C6 by-products include methylcyclopentane and methylenecyclopentane.

7. The method for separating solution polymerization products according to claim 1, characterized in that: The dual-walled column includes a first walled column and a second walled column. The sidestream product of the first walled column yields 1-octene. The bottom product of the first walled column yields a heavy component, and the top product of the first walled column yields 1-hexene, a C6 byproduct, and solvent. The top product of the first walled column flows to the second walled column. The top product of the second walled column yields 1-hexene, the sidestream product of the second walled column yields a C6 byproduct, and the bottom product of the second walled column yields a recycled solvent. The distillation temperature of the first walled column is 50-300℃, and the operating pressure is -0.1-0.3 MPaG. The distillation temperature of the second walled column is 50-250℃, and the operating pressure is 0.01-0.3 MPaG. The C6 byproduct includes methylcyclopentane and methylenecyclopentane.

8. The method for separating solution polymerization products according to claim 1, characterized in that: The catalyst for solution polymerization includes ligand a, transition metal compound b, and activator c. Ligand a includes PNP ligands, PNNP ligands, and rigid linking groups. Transition metal compound b is a metal compound of group IVB-VIII. Activator c is a compound containing a group IIIA metal.

Images