Water-based adsorptive slurry, method for preparing the same, and method for separating near-boiling point light hydrocarbon mixture liquid phase

Abstract

The application provides a water-based adsorption slurry, a preparation method thereof and a liquid phase separation method of near-boiling point light hydrocarbon mixture, wherein, based on the total weight of the water-based adsorption slurry being 100%, the water-based adsorption slurry comprises: 5-40% of hydrophobic solid adsorbent; 0.1-2% of non-ionic surfactant; 0.01-1% of defoaming agent; and the balance of deionized water; wherein the hydrophobic solid adsorbent comprises one or a combination of several of metal organic framework material, porous silicate material, carbonaceous adsorbent and zeolite. The non-ionic surfactant in the water-based adsorption slurry can improve the hydrophilic and hydrophobic properties of the hydrophobic solid adsorbent, prevent Pickering emulsification, the defoaming agent can quickly destroy the foam structure, solve the problem of desorption foam, through the synergistic effect of the two, the application limitation of pure water-based slurry is broken, and the water-based adsorption slurry is first applied to the industrialization of liquid phase near-boiling point light hydrocarbon mixture (liquid phase light hydrocarbon) separation.

Description

Technical Field

[0001] This invention relates to a water-based adsorption slurry and its preparation method, as well as a liquid-phase separation method for near-boiling point light hydrocarbon mixtures, belonging to the field of chemical separation technology. Background Technology

[0002] Industrial chemical separation processes consume 10-15% of global energy demand, and the separation of hydrocarbons during oil refining is a recognized global challenge. High-purity light hydrocarbons are important chemical feedstocks, and the separation of light naphtha fractions (C5 and C6 alkane isomers) is crucial for optimizing steam cracking and catalytic reforming feedstocks and producing high-octane gasoline. C5 and C6 alkane isomers, especially branched isomers, are ideal components for improving the octane rating (RON) of gasoline. For example, isopentane has an octane rating as high as 93, while n-pentane is only 62; among hexane isomers, 2,3-dimethylbutane has an octane rating of 101.7, while n-hexane is only 24.8. Therefore, the efficient separation of light hydrocarbon isomers plays an extremely important role in the petrochemical industry.

[0003] Currently, industrial separation mainly employs distillation technology. However, due to the extremely similar physical properties of isomers (e.g., the boiling points of n-pentane and isopentane are approximately 36.1℃ and 28℃ respectively, with a boiling point difference of only 8.1℃), high theoretical plate numbers (over 80) and extremely high reflux ratios (up to 17.21) are required, resulting in enormous energy consumption and high equipment investment. Although extractive distillation can reduce some energy consumption, it requires the introduction of a third component solvent (such as acetonitrile, DMF, NMP, etc.), which presents problems such as complex processes, high solvent recovery costs, and high environmental pollution risks.

[0004] Adsorption separation technology based on porous adsorbents is considered an energy-saving technology to replace or supplement traditional thermally driven cryogenic distillation processes. It can separate gas / liquid mixtures near room temperature and has the advantages of lower energy consumption and less carbon dioxide emissions.

[0005] Metal-organic frameworks (MOFs) are porous adsorbents with designable structures, attracting widespread attention in molecular recognition and gas separation applications. Among them, zeolite imidazole ester framework material-8 (ZIF-8) has garnered significant interest due to its unique physicochemical properties. ZIF-8 possesses a regular microporous structure (effective pore size approximately 0.34 nm) and a high specific surface area (1000-1500 m²). 2 It also exhibits excellent thermal stability (>500℃) and chemical stability.

[0006] ZIF-8 achieves isomer separation through steric kinetics: linear n-pentane (kinetic diameter approximately 4.3 Å) diffuses through the pores via the flexible "gate-switch" effect of the framework, while branched isopentane (kinetic diameter approximately 5.0 Å) diffuses at a much lower rate due to steric hindrance. In 2006, Chen Banglin's research group first reported the application of MOF-508 material to the separation of straight-chain and branched hexane isomers (Angew. Chem. Int. Ed. 2006, 45, 5537-5540.). Recent studies have shown that the ZIF-8 / DMPU-water slurry system can achieve separation factors of 94-1877 and n-pentane recovery rates exceeding 98% in the gas phase separation of pentane isomers, fully demonstrating the enormous potential of ZIF-8 slurry technology (Sep. Purif. Technol. 2023, 310, 123203.).

[0007] Existing technologies related to adsorption separation based on porous adsorbents have the following main shortcomings: (1) Limitations of pure powder adsorbents: Using ZIF-8 or other porous adsorbents directly in powder form for liquid phase separation has the following problems: particles are prone to agglomeration, which significantly reduces the effective interface area; mass transfer resistance is large and separation efficiency is low; continuous industrial operation is difficult to achieve and solid-liquid separation is difficult.

[0008] (2) Defects of non-aqueous slurries (DMAC, DMPU, etc.): Although non-aqueous slurries have excellent separation performance (gas phase separation factor can reach 94-1877), they have problems such as high solvent cost, poor economic efficiency, low environmental performance, pollution risk to the environment, and complex solvent recovery, making industrialization difficult.

[0009] (3) For water-based slurries, although they are environmentally friendly and low-cost, there are two major engineering challenges in liquid phase separation applications: Pickering emulsification and depressurization desorption foaming. Specifically, for the former, MOF materials such as ZIF-8 have hydrophobic surfaces. When in contact with liquid hydrocarbon mixtures, particles tend to aggregate at the oil-water interface to form stable Pickering emulsions, which causes the slurry viscosity to rise sharply and completely lose its fluidity, directly leading to the inability to carry out the separation process. This is the fatal weakness of pure water-based slurries. For the latter, during vacuum desorption, pure water-based slurries will generate a large amount of stable foam, and the foam is not easy to dissipate, which leads to serious liquid level control problems. In addition, pure water-based slurries may also escape from the vacuum port with the gas flow, posing serious safety hazards.

[0010] Therefore, researching, developing, and providing a water-based adsorption slurry and its preparation method, as well as a liquid-phase separation method for near-boiling light hydrocarbon mixtures, to prevent Pickering emulsification and solve the desorption foaming problem, thereby achieving liquid-phase separation of near-boiling light hydrocarbon mixtures by water-based slurry, remains a current technical challenge. Summary of the Invention

[0011] To address the aforementioned shortcomings and deficiencies, the present invention aims to provide a water-based adsorption slurry, its preparation method, and a method for liquid-phase separation of near-boiling light hydrocarbon mixtures. The present invention introduces a nonionic surfactant and an antifoaming agent into the water-based adsorption slurry. When using this water-based adsorption slurry for liquid-phase separation of near-boiling light hydrocarbon mixtures, it can at least prevent Pickering emulsification and solve the desorption foaming problem.

[0012] To achieve the above objectives, in one respect, the present invention provides a water-based adsorption slurry, wherein, based on the total weight of the water-based adsorption slurry as 100%, it comprises: 5-40% hydrophobic solid adsorbent; 0.1-2% nonionic surfactant; 0.01-1% (preferably 0.1-1%) of defoamer; And the remaining deionized water; The hydrophobic solid adsorbent includes one or a combination of several of the following: metal-organic framework materials, porous silicate materials, carbonaceous adsorbents, and zeolites.

[0013] As a specific embodiment of the water-based adsorption slurry described above in this invention, the metal-organic framework material is a ZIF series metal-organic framework material, including one or a combination of several of ZIF-8, ZIF-67 and ZIF-71.

[0014] In the water-based adsorption slurry described above in this invention, the porous silicate materials, carbonaceous adsorbents, and zeolite adsorbents are all conventional materials. This invention does not impose specific requirements on the specific substances used; they can be selected as needed, as long as they are hydrophobic solid adsorbents. For example, in some embodiments of this invention, the porous silicate material can be a porous silicate material with adjustable pore size, and the carbonaceous adsorbent can be a carbonaceous microporous adsorbent. When the hydrophobic solid adsorbents used in this invention have micropores, the pore size of the micropores can be 0.2-1.0 nm.

[0015] As a specific embodiment of the water-based adsorption slurry described above in this invention, the nonionic surfactant includes one or a combination of several of the following: polysorbates, polyoxyethylene fatty acid ethers, polyoxyethylene fatty acid esters, and alkylphenol polyoxyethylene ether nonionic surfactants.

[0016] As a specific embodiment of the water-based adsorption slurry described above in this invention, the polysorbate nonionic surfactant includes one or a combination of several of Tween20, Tween40, Tween60 and Tween80.

[0017] As a specific embodiment of the water-based adsorption slurry described above in this invention, the polyoxyethylene fatty acid ether nonionic surfactant includes Brij 35 and / or Brij 58, etc.

[0018] As a specific embodiment of the water-based adsorption slurry described above in this invention, the polyoxyethylene fatty acid ester nonionic surfactant includes Myrj52 and / or Myrj59, etc.

[0019] As a specific embodiment of the water-based adsorption slurry described above in this invention, the alkylphenol polyoxyethylene ether nonionic surfactant includes one or a combination of several of OP-7, OP-10, OP-15 and O-25.

[0020] The nonionic surfactants used in this invention, such as Tween20, Tween40, Tween60, Tween80, Brij 35, Brij 58, Myrj52, Myrj59, OP-7, OP-10, OP-15 and O-25, are all conventional substances that can be obtained commercially.

[0021] As a specific embodiment of the water-based adsorption slurry described above in this invention, the defoamer includes one or a combination of several of the following: organosilicon, polyether-modified silicone, and polyether defoamers.

[0022] As a specific embodiment of the water-based adsorption slurry described above in this invention, the organosilicon defoamer includes one or a combination of several of BYK-019, BYK-022 and BYK-024.

[0023] As a specific embodiment of the water-based adsorption slurry described above in this invention, the polyether-modified silicone defoamer includes polyether-modified silicone 4060 and / or polyether-modified silicone 303E, etc.

[0024] As a specific embodiment of the water-based adsorption slurry described above in this invention, the polyether defoamer includes GP-330 and / or GPE-3000, etc.

[0025] The defoamers used in this invention, such as BYK-019, BYK-022, BYK-024, polyether modified silicone 4060, polyether modified silicone 303E, GP-330, and GPE-3000, are all conventional substances that can be obtained commercially.

[0026] This invention innovatively introduces nonionic surfactants and defoamers into a water-based adsorption slurry. When using this slurry for liquid-phase separation of near-boiling light hydrocarbon mixtures, the nonionic surfactants can form a colloidal layer or adsorption film on the surface of hydrophobic solid adsorbent particles, thereby altering the hydrophilic-hydrophobic properties of the particle surface to make it "amphiphilic." This prevents the hydrophobic solid adsorbent particles from agglomerating at the oil-water interface to form Pickering emulsions, ensuring that the solid adsorbent particles maintain good dispersibility and flowability in the water-hydrocarbon mixture. Meanwhile, the defoamer can rapidly reduce the surface tension of the liquid during vacuum desorption, disrupting the stability of the foam film, accelerating bubble dissipation, and significantly reducing foam generation during depressurization, thus improving the safety and operational stability of the depressurization desorption process. Simultaneously, the nonionic surfactants and defoamers work synergistically within the target concentration range (i.e., they have a synergistic effect), balancing uniform dispersion of the adsorbent, slurry flowability, anti-emulsification ability, and rapid defoaming performance, giving the slurry multiple excellent properties to meet the needs of industrial applications. In other words, the synergistic effect of nonionic surfactants and defoamers within the target concentration range enables water-based adsorption slurries to exhibit excellent flowability, dispersion stability, and rapid defoaming performance for liquid-phase near-boiling light hydrocarbon mixtures.

[0027] On the other hand, the present invention also provides a method for preparing the above-mentioned water-based adsorption slurry, wherein the preparation method includes: The hydrophobic solid adsorbent, nonionic surfactant, defoamer and deionized water are mixed evenly until a stable solid-liquid suspension is formed, thus obtaining the water-based adsorption slurry.

[0028] As a specific embodiment of the preparation method described above in this invention, the uniform mixing is achieved by mechanical stirring at room temperature; Preferably, the uniform mixing is achieved by mechanical stirring at room temperature and ultrasonic dispersion treatment to obtain better dispersion effect, higher uniformity and better long-term stability.

[0029] In one specific embodiment of the preparation method described above in this invention, the mechanical stirring may be, for example, magnetic stirring.

[0030] The present invention does not specify the order of addition of various raw materials such as hydrophobic solid adsorbent, nonionic surfactant, defoamer and deionized water in the preparation method described above. The order can be reasonably adjusted according to the actual process requirements, as long as the water-based adsorption slurry can be obtained.

[0031] In some preferred embodiments of the present invention, the raw material mixing sequence during the preparation of the water-based adsorption slurry includes: First, add deionized water to the target container, then add a nonionic surfactant, then add an antifoaming agent, and finally add a hydrophobic solid adsorbent.

[0032] In another aspect, the present invention also provides a method for liquid-phase separation of near-boiling point light hydrocarbon mixtures, wherein the adsorbent used in the liquid-phase separation method is the water-based adsorption slurry described above.

[0033] As a specific embodiment of the liquid phase separation method described above in this invention, the liquid phase separation method specifically includes: Adsorption stage: The water-based adsorption slurry is mixed with the near-boiling light hydrocarbon mixture to be separated and stirred at the adsorption temperature to promote full contact and mass transfer between the hydrophobic solid adsorbent and the near-boiling light hydrocarbon mixture to be separated. Liquid-solid separation stage: After adsorption reaches equilibrium, the mixture of water-based adsorption slurry and near-boiling light hydrocarbon mixture is centrifuged to obtain three-phase products: the supernatant is the remaining adsorption product, the lower liquid is a mixture of deionized water, nonionic surfactant and defoamer, and the precipitate is a hydrophobic solid adsorbent enriched with the adsorption phase. Desorption stage: The precipitate is heated to the desorption temperature and desorbed under vacuum conditions. After the desorbed gas is cooled and condensed, the adsorbed phase is obtained, thus completing the liquid phase separation of the near-boiling point light hydrocarbon mixture.

[0034] In the liquid-phase separation method described above in this invention, when the near-boiling point light hydrocarbon mixture contains both normal and isohydrocarbons, the adsorption phase is mainly normal hydrocarbons, while the remaining adsorption product is mainly isohydrocarbons. The desorbed gas released during the desorption stage is primarily normal hydrocarbons, which can essentially be used directly as a product rich in normal hydrocarbons.

[0035] As a specific embodiment of the liquid phase separation method described above in this invention, the liquid phase separation method further includes the recycling and reuse of the water-based adsorption slurry. The separation performance of the water-based adsorption slurry remains stable after multiple recycling cycles, thereby enabling green and economical industrial applications.

[0036] In one specific embodiment of the liquid phase separation method described above in this invention, the stirring during the adsorption stage can be magnetic stirring or mechanical stirring, etc.

[0037] As a specific embodiment of the liquid phase separation method described above in this invention, the near-boiling point light hydrocarbon mixture includes a light hydrocarbon mixture with a boiling point difference of less than 20°C. Preferably, the near-boiling point light hydrocarbon mixture includes a mixture of olefins and alkanes, a mixture of straight-chain hydrocarbons and branched-chain hydrocarbons, or a mixture of cyclic hydrocarbons and alkanes, etc. More preferably, the near-boiling point light hydrocarbon mixture includes a mixture of C5 hydrocarbon isomers or a mixture of C6 hydrocarbon isomers, etc. More preferably, the C5 hydrocarbon isomer mixture includes a combination of two or more of n-pentane, isopentane, cyclopentane, 1-pentene, 2-pentene, and cyclopentene, and even more preferably a mixture of n-pentane and isopentane or a mixture of n-pentane and cyclopentane, etc. More preferably, the mixture of C6 hydrocarbon isomers includes a combination of two or more of the following: n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, cyclohexane, methylcyclopentane, 1-hexene, and 2-hexene. More preferably, it is any one of the following: a mixture of n-hexane and methylcyclopentane, a mixture of n-hexane and 2-methylpentane, or a mixture of n-hexane and 3-methylpentane.

[0038] In a specific embodiment of the liquid phase separation method described above in this invention, the adsorption temperature is 15-30℃; the adsorption time is 10-120 min; the desorption temperature is 60-180℃; the desorption pressure is 0.1-5 kPa; and the desorption time is 30-120 min.

[0039] As a specific embodiment of the liquid phase separation method described above in this invention, when the near-boiling point light hydrocarbon mixture is a mixture of C5 hydrocarbon isomers: The adsorption temperature is 15-30℃; The adsorption time is 40-90 min; The desorption temperature is 60-110℃; The desorption pressure is 0.1-5 kPa; The desorption time is 30-60 minutes; The volume ratio of the water-based adsorption slurry to the C5 hydrocarbon isomer mixture is 1-30:1, preferably 5-10:1.

[0040] As a specific embodiment of the liquid phase separation method described above in this invention, wherein the near-boiling point light hydrocarbon mixture is a mixture of C6 hydrocarbon isomers: The adsorption temperature is 15-30℃; The adsorption time is 10-90 min; The desorption temperature is 90-150℃; The desorption pressure is 0.1-5 kPa; The desorption time is 30-120 min; The volume ratio of the water-based adsorption slurry to the C6 hydrocarbon isomer mixture is 1-30:1, preferably 5-10:1.

[0041] Generally, the longer the carbon chain of the substance to be separated in the near-boiling light hydrocarbon mixture, the higher the desorption temperature and the longer the desorption time.

[0042] The liquid phase separation method of the present invention can optimize the separation of near-boiling light hydrocarbon mixtures with different compositions by adjusting parameters such as operating temperature (adsorption temperature and desorption temperature), adsorption time, and the ratio of slurry to near-boiling light hydrocarbon mixture, fully demonstrating the versatility and adaptability of the liquid phase separation method for water-based adsorption slurry and near-boiling light hydrocarbon mixture.

[0043] Compared with the prior art, the beneficial technical effects achieved by the present invention include at least the following: (1) Achieve direct liquid-phase separation of near-boiling-point light hydrocarbon mixtures, significantly reducing energy consumption: This invention innovatively adds nonionic surfactants and defoamers to an aqueous adsorption slurry containing a hydrophobic solid adsorbent, utilizing their synergistic effect to achieve direct liquid-phase separation of near-boiling-point light hydrocarbon mixtures without the need for carrier gas or material gasification processes, and under mild operating conditions (adsorption is performed at ambient temperature and pressure). Compared to traditional distillation methods, the liquid-phase separation method of this invention can reduce energy consumption by more than 60%. Compared to gas-phase separation methods, the liquid-phase separation method of this invention avoids high-temperature and high-pressure operations, resulting in a simpler process flow.

[0044] (2) A breakthrough solution has been achieved in solving the engineering application challenges of water-based adsorption slurry in the direct liquid-phase separation of near-boiling light hydrocarbon mixtures: This invention innovatively adds nonionic surfactants and defoamers to a water-based adsorption slurry containing a hydrophobic solid adsorbent. Utilizing their synergistic effect, it successfully solves two major engineering challenges in the direct liquid-phase separation of near-boiling light hydrocarbon mixtures from pure water-based slurries: Pickering emulsification and depressurized desorption foaming. The water-based adsorption slurry formulation system provided by this invention achieves a harmonious balance between three key elements: uniform dispersion of adsorbent particles, anti-emulsification ability of the slurry, and rapid defoaming performance, simultaneously addressing these two major engineering obstacles within a single system.

[0045] (3) Excellent separation effect and high product purity: In some preferred embodiments of the present invention, taking the direct liquid-phase separation of C5 hydrocarbon isomers (n-pentane / isopentane) as an example: the purity of the liquid product (adsorption residue) isopentane is 99.31%, which meets or exceeds the existing industrial standards; the enrichment of the gas product (desorption product) n-pentane is 85.45%, which is significantly improved compared to the initial mixture; and the separation factor is also significantly improved compared to the average value of the gas-phase ZIF-8 / DMPU system in the literature. For the direct liquid-phase separation of the C6 hydrocarbon isomer n-hexane / 2-methylpentane, the separation factor can also reach 218-322. Furthermore, the separation performance is stable, and the adsorption can be repeated under normal temperature and pressure conditions, indicating that the system has good process stability and repeatability.

[0046] (4) Excellent recyclability and long-term use: The water-based adsorption slurry provided by this invention was evaluated after being recycled 10 times. The evaluation results showed that the separation performance did not significantly decrease after 10 cycles. The crystal structure of the hydrophobic solid adsorbent, such as ZIF-8, was completely preserved. The XRD spectrum was consistent with that of the fresh sample, and there were no signs of degradation. This proves that the water-based adsorption slurry provided by this invention has excellent recycling performance and can be used for a long time, which greatly reduces the separation cost and improves economic feasibility.

[0047] In summary, this invention innovatively adds nonionic surfactants and defoamers to an aqueous adsorption slurry containing a hydrophobic solid adsorbent. When using this aqueous adsorption slurry for direct liquid-phase separation of near-boiling light hydrocarbon mixtures, the nonionic surfactant improves the hydrophilicity and hydrophobicity of the hydrophobic solid adsorbent, preventing Pickering emulsification, while the defoamer quickly destroys the foam structure, solving the desorption foam problem. Through the synergistic effect of the two, the limitations of pure aqueous slurries are overcome, enabling their industrial application in liquid-phase light hydrocarbon separation for the first time. Furthermore, the liquid-phase separation method provided by this invention is simple, energy-efficient, and environmentally friendly, offering a new technical path for the industrial separation of near-boiling light hydrocarbon mixtures, such as mixtures of light hydrocarbon isomers. Attached Figure Description

[0048] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0049] Figure 1 This is a time series diagram of the sedimentation stability of the water-based adsorption slurry provided in Example 1 of the present invention. Figure 1(a) 24h; (b) 12h; (c) 8h; (d) 6h; (e) 4h; (f) 2h; (g) 1h.

[0050] Figure 2 Viscosity-temperature curves of the water-based adsorption slurry provided in Examples 1-3 of this invention.

[0051] Figure 3a This is a state diagram before centrifugation during the liquid-solid separation stage of the liquid-phase separation process of a liquid mixture of n-pentane and isopentane using the water-based adsorption slurry provided in Example 1 of the present invention.

[0052] Figure 3b This is a state diagram after centrifugation during the liquid-solid separation stage of the liquid-phase separation process of a liquid mixture of n-pentane and isopentane using the water-based adsorption slurry provided in Example 1 of the present invention.

[0053] Figure 4a This is a diagram showing the emulsification characteristics of the water-based adsorption slurry provided in Example 1 of the present invention after contact with a liquid mixture of n-pentane and isopentane.

[0054] Figure 4b The diagram shows the emulsification characteristics of the water-based adsorption slurry provided in Comparative Example 1 after contact with a liquid mixture of n-pentane and isopentane.

[0055] Figure 5a The diagram shows the defoaming effect of desorption under reduced pressure during the desorption stage of the liquid phase separation process of a liquid mixture of n-pentane and isopentane using the water-based adsorption slurry provided in Example 1 of this invention.

[0056] Figure 5b The diagram shows the defoaming effect of depressurized desorption during the desorption stage of the liquid phase separation process of a liquid mixture of n-pentane and isopentane using the water-based adsorption slurry provided in Comparative Example 1.

[0057] Figure 6 The image shows a comparison of X-ray diffraction patterns of fresh ZIF-8 in the water-based adsorption slurry provided in Example 1 of the present invention and the ZIF-8 recovered after 10 cycles of the water-based adsorption slurry.

[0058] Figure 7a This is a scanning electron microscope image of fresh ZIF-8 in the water-based adsorption slurry provided in Example 1 of the present invention.

[0059] Figure 7b The image shows a scanning electron microscope image of ZIF-8 recovered from the water-based adsorption slurry provided in Example 1 of this invention after 10 cycles (i.e., 10 cycles of adsorption-desorption). Detailed Implementation

[0060] It should be noted that the term "comprising" and any variations thereof in the specification, claims, and accompanying drawings of this invention are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to such processes, methods, products, or devices.

[0061] The "range" disclosed in this invention is given in the form of a lower limit and an upper limit. It can be one or more lower limits and one or more upper limits, respectively. A given range is defined by selecting a lower limit and an upper limit. The selected lower and upper limits define the boundaries of the particular range. All ranges defined in this way are composable, meaning that any lower limit can be combined with any upper limit to form a range. For example, if ranges of 60-120 and 80-110 are listed for specific parameters, it is also expected that ranges of 60-110 and 80-120 are also expected. Furthermore, if the listed minimum range values ​​are 1 and 2, and the listed maximum range values ​​are 3, 4, and 5, then the following ranges are all expected: 1-3, 1-4, 1-5, 2-3, 2-4, and 2-5.

[0062] In this invention, unless otherwise specified, the numerical range "ab" represents a shortened representation of any combination of real numbers between a and b, where a and b are real numbers. For example, the numerical range "0-5" indicates that all real numbers between "0-5" have been listed in this invention, and "0-5" is simply a shortened representation of these numerical combinations.

[0063] In this invention, unless otherwise specified, all embodiments and preferred embodiments mentioned in this invention can be combined with each other to form new technical solutions.

[0064] In this invention, unless otherwise specified, all technical features and preferred features mentioned in this invention can be combined with each other to form new technical solutions.

[0065] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to tables, drawings, and embodiments. The embodiments described below are some, but not all, embodiments of this invention, and are only used to illustrate the invention, and should not be considered as limiting the scope of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of this invention without creative effort are within the scope of protection of this invention. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0066] Example 1

[0067] This embodiment provides a water-based adsorption slurry, wherein, based on the total weight of the water-based adsorption slurry as 100%, it comprises: 30% ZIF-8; 1% of Tween20; 0.1% BYK-019; And the remaining deionized water.

[0068] To prepare the water-based adsorption slurry, 6.89 g of deionized water was first added to the target container, followed by 0.1 g of Tween20, then 0.01 g of BYK-019, and finally 3 g of ZIF-8. After mechanical stirring at room temperature for 30 min, ultrasonic dispersion was performed to form a stable solid-liquid suspension slurry, which is the water-based adsorption slurry, denoted as ZIF-8(30%) / water slurry.

[0069] The water-based adsorption slurry provided in this embodiment is a uniform, light yellow suspension without obvious stratification. The sedimentation stability test results of this water-based adsorption slurry are as follows: Figure 1 As shown, from Figure 1 As can be seen, the water-based adsorption slurry did not show obvious sedimentation and stratification after standing for 12 hours, indicating that it has excellent sedimentation stability.

[0070] Example 2

[0071] This embodiment provides a water-based adsorption slurry, wherein, based on the total weight of the water-based adsorption slurry as 100%, it comprises: 20% ZIF-8; 1% of Tween20; 0.1% BYK-019; And the remaining deionized water.

[0072] To prepare the water-based adsorption slurry, 7.89 g of deionized water was first added to the target container, followed by 0.1 g of Tween20, then 0.01 g of BYK-019, and finally 2 g of ZIF-8. After mechanical stirring at room temperature for 30 min, ultrasonic dispersion was performed to form a stable solid-liquid suspension slurry, which is the water-based adsorption slurry, denoted as ZIF-8(20%) / water slurry.

[0073] Example 3

[0074] This embodiment provides a water-based adsorption slurry, wherein, based on the total weight of the water-based adsorption slurry as 100%, it comprises: 40% ZIF-8; 1% of Tween20; 0.1% BYK-019; And the remaining deionized water.

[0075] To prepare the water-based adsorption slurry, 5.89 g of deionized water was first added to the target container, followed by 0.1 g of Tween20, then 0.01 g of BYK-019, and finally 4 g of ZIF-8. After mechanical stirring at room temperature for 30 min, ultrasonic dispersion was performed to form a stable solid-liquid suspension slurry, which is the water-based adsorption slurry, denoted as ZIF-8(40%) / water slurry.

[0076] The viscosity-temperature curves of the water-based adsorption slurry provided in Examples 1-3 of this invention are shown in the figure below. Figure 2 As shown. From Figure 2 As can be seen, for the same water-based adsorption slurry, its viscosity gradually decreases with increasing temperature, while under the same temperature conditions, the viscosity of the water-based adsorption slurry gradually increases with increasing ZIF-8 content.

[0077] Example 4

[0078] This embodiment provides a water-based adsorption slurry, which differs from Embodiment 1 only in that: The content of Tween20 is 0.1%, and correspondingly, when preparing the water-based adsorption slurry, the amount of Tween20 used is 0.01g and the amount of deionized water used is 6.98g.

[0079] Example 5

[0080] This embodiment provides a water-based adsorption slurry, which differs from Embodiment 1 only in that: The content of Tween20 is 1.5%. Accordingly, when preparing the water-based adsorption slurry, the amount of Tween20 used is 0.15g and the amount of deionized water used is 6.84g.

[0081] Example 6

[0082] This embodiment provides a water-based adsorption slurry, which differs from Embodiment 1 only in that: The content of Tween20 is 2%, and correspondingly, when preparing the water-based adsorption slurry, the amount of Tween20 used is 0.2g and the amount of deionized water is 6.79g.

[0083] Example 7

[0084] This embodiment provides a water-based adsorption slurry, which differs from Embodiment 1 only in that: The content of BYK-019 is 0.05%. Accordingly, when preparing the water-based adsorption slurry, the amount of BYK-019 is 0.005g and the amount of deionized water is 6.895g.

[0085] Example 8

[0086] This embodiment provides a water-based adsorption slurry, which differs from Embodiment 1 only in that: The content of BYK-019 is 0.5%. Accordingly, when preparing the water-based adsorption slurry, the amount of BYK-019 is 0.05g and the amount of deionized water is 6.85g.

[0087] Example 9

[0088] This embodiment provides a water-based adsorption slurry, which differs from Embodiment 1 only in that: The content of BYK-019 is 1%, and correspondingly, when preparing the water-based adsorption slurry, the amount of BYK-019 is 0.1g and the amount of deionized water is 6.8g.

[0089] Comparative Example 1

[0090] This comparative example provides a water-based adsorption slurry, which differs from Example 1 only in that: It does not contain Tween20, and correspondingly, the amount of deionized water used in preparing the water-based adsorption slurry is 6.99g.

[0091] Comparative Example 2

[0092] This comparative example provides a water-based adsorption slurry, which differs from Example 1 only in that: The content of Tween20 is 3%. Accordingly, when preparing the water-based adsorption slurry, the amount of Tween20 used is 0.3g and the amount of deionized water used is 6.69g.

[0093] Comparative Example 3

[0094] This comparative example provides a water-based adsorption slurry, which differs from Example 1 only in that: Without BYK-019, the amount of deionized water used in preparing the water-based adsorption slurry is 6.9g.

[0095] Comparative Example 4

[0096] This comparative example provides a water-based adsorption slurry, which differs from Example 1 only in that: The content of BYK-019 is 2%. Accordingly, when preparing the water-based adsorption slurry, the amount of BYK-019 is 0.2g and the amount of deionized water is 6.7g.

[0097] Application Examples and Comparative Examples

[0098] The water-based adsorption slurry provided in Examples 1-9 and Comparative Examples 1-4 of this invention was used for the separation of n-pentane and isopentane liquid mixtures, which included the following specific steps: Adsorption stage: Each water-based adsorption slurry is mixed with the liquid mixture of n-pentane and isopentane to be separated, and magnetic stirring is performed at the adsorption temperature to promote full contact and mass transfer between ZIF-8 and the liquid mixture of n-pentane and isopentane to be separated. Liquid-solid separation stage: After adsorption reaches equilibrium, the mixture of water-based adsorption slurry and liquid mixture of n-pentane and isopentane is centrifuged to obtain three-phase products: the supernatant is the remaining adsorption product (isopentane), the lower liquid is a mixture of deionized water, Tween20, and BYK-019, and the precipitate is ZIF-8 enriched with the adsorption phase (n-pentane); wherein, for the water-based adsorption slurry provided in Example 1, the state diagrams before and after centrifugation are as follows. Figure 3a and Figure 3b As shown; Desorption stage: The precipitate is heated to the desorption temperature and desorbed under vacuum conditions. After the desorbed gas is cooled and condensed, the adsorbed phase is obtained, thus completing the liquid phase separation of the n-pentane and isopentane liquid mixture.

[0099] In the liquid mixture of n-pentane and isopentane, the mass ratio of n-pentane to isopentane is 15:85. Adsorption stage conditions: adsorption temperature 25℃, adsorption time 60min, volume ratio of water-based adsorption slurry to n-pentane and isopentane liquid mixture 6.25:1; Conditions for the liquid-solid separation stage: rotation speed 5000 rpm, time 5 min; Under the following conditions during the desorption stage: desorption temperature 100℃, vacuum pressure 5kPa, and desorption time 60 min.

[0100] The separation results are shown in Table 1 below.

[0101] Table 1

[0102] In the application process, the effect of nonionic surfactant concentration on the dispersibility and separation effect of the water-based adsorption slurry was investigated using the water-based adsorption slurries provided in Examples 1, 4-6, and Comparative Examples 1-2. Specifically, the stratification rate and degree, emulsification with liquid pentane, and viscosity were examined. Specific experimental results are shown in Table 2 and... Figures 4a-4b As shown.

[0103] Table 2

[0104] contrast Figure 4a and Figure 4b It can be seen that the water-based adsorption slurry provided in Example 1 of the present invention does not emulsify after contacting the liquid mixture of n-pentane and isopentane, while the water-based adsorption slurry provided in Comparative Example 1 emulsifies severely after contacting the liquid mixture of n-pentane and isopentane.

[0105] Combine Table 2 and Figures 4a-4b It can be seen that, under the same conditions, water-based adsorption slurries with a nonionic surfactant content of 0.1-2% exhibit relatively superior stratification speed and degree, show no emulsification or only slight emulsification when in contact with liquid mixtures of n-pentane and isopentane, and have relatively low viscosity. Among them, the water-based adsorption slurry provided in Example 1 (with a Tween20 content of 1 wt%) shows the best performance.

[0106] In the application process, the effect of defoamer concentration on desorption foam during the desorption stage was investigated using the water-based adsorption slurries provided in Examples 1, 7-9, and Comparative Examples 3-4. Specifically, the maximum foam height, defoaming time, and viscosity were examined. The specific experimental results are shown in Table 3 and... Figures 5a-5b As shown.

[0107] Table 3

[0108] contrast Figure 5a and Figure 5b It can be seen that the depressurization desorption and defoaming effect of the water-based adsorption slurry provided in Example 1 of the present invention for direct liquid-phase separation of n-pentane and isopentane liquid mixture is significantly better than that of the water-based adsorption slurry provided in Comparative Example 1.

[0109] Combined with Table 3 and Figures 5a-5b It can be seen that, under the same conditions, water-based adsorption slurries with a defoamer content of 0.01-1 wt% all exhibit relatively superior depressurization desorption defoaming effects. Among them, water-based adsorption slurries with a defoamer content of 0.1-1 wt% all exhibit even superior depressurization desorption defoaming effects.

[0110] In the application process, taking the water-based adsorption slurry provided in Example 1 of the present invention as an example, after the direct liquid-phase separation of the liquid mixture of n-pentane and isopentane, the water-based adsorption slurry is recycled to verify the long-term stability and recyclability of the water-based adsorption slurry, and the molar contents of n-pentane and isopentane in the liquid phase and the gas phase and the separation factor β are recorded, as shown in Table 4.

[0111] Table 4

[0112] The X-ray diffraction comparison of fresh ZIF-8 in the water-based adsorption slurry provided in Example 1 of this invention and the ZIF-8 recovered after 10 cycles of the water-based adsorption slurry is shown in the figure below. Figure 6 As shown. A scanning electron microscope image of fresh ZIF-8 in the water-based adsorption slurry provided in Example 1 of this invention is shown below. Figure 7a The scanning electron microscope image shown is of ZIF-8 recovered after the water-based adsorption slurry provided in Example 1 of this invention has been circulated 10 times (i.e., 10 cycles of adsorption-desorption). Figure 7b As shown.

[0113] From Table 4, Figure 6 and Figures 7a-7b It can be seen that after 10 cycles of use, the water-based adsorption slurry provided in Example 1 of the present invention retains the ZIF-8 crystal structure completely, shows no signs of degradation, and exhibits stable separation performance, indicating that the water-based adsorption slurry has excellent cycle stability and long-term use feasibility.

[0114] Example 10

[0115] This embodiment provides a water-based adsorption slurry, wherein, based on the total weight of the water-based adsorption slurry as 100%, it comprises: 20% ZIF-8; 1.5% Brij 35; 0.2% GPE-3000; And the remaining deionized water.

[0116] To prepare the water-based adsorption slurry, 8g of deionized water was first added to the target container, followed by 0.15g of Brij 35, then 0.02g of GPE-3000, and finally 2g of ZIF-8. After mechanical stirring at room temperature for 30 min, ultrasonic dispersion was performed to form a stable solid-liquid suspension slurry, thus obtaining the water-based adsorption slurry.

[0117] The water-based adsorption slurry provided in Example 10 of this invention is used for the separation of a liquid mixture of n-hexane and 2-methylpentane, which includes the following specific steps: Adsorption stage: The water-based adsorption slurry is mixed with the liquid mixture of n-hexane and 2-methylpentane to be separated, and magnetic stirring is performed at the adsorption temperature to promote full contact and mass transfer between ZIF-8 and the liquid mixture of n-hexane and 2-methylpentane to be separated. Liquid-solid separation stage: After adsorption reaches equilibrium, the mixture of water-based adsorption slurry and liquid mixture of n-hexane and 2-methylpentane is centrifuged to obtain three-phase products: the supernatant is the remaining adsorption product (2-methylpentane), the lower liquid is a mixture of deionized water, Brij 35 and GPE-3000, and the precipitate is ZIF-8 enriched with adsorption phase (n-hexane); Desorption stage: The precipitate is heated to the desorption temperature and desorbed under vacuum. After the desorbed gas is cooled and condensed, the adsorbed phase is obtained, thus completing the liquid-phase separation of the liquid mixture of n-hexane and 2-methylpentane.

[0118] In the liquid mixture of n-hexane and 2-methylpentane, the mass ratio of n-hexane to 2-methylpentane is 2:8; Adsorption stage conditions: adsorption temperature 25℃, adsorption time 20min, volume ratio of water-based adsorption slurry to liquid mixture of n-hexane and 2-methylpentane 10:1; Conditions for the liquid-solid separation stage: rotation speed 6000 rpm, time 5 min; Under the following conditions during the desorption stage: desorption temperature 130℃, vacuum pressure 5kPa, and desorption time 80min.

[0119] Experimental results showed that the purity of 2-methylpentane in the liquid phase product was 99.21 mol%, the enrichment of n-hexane in the gas phase product was 79.4 mol%, and the separation factor β was 301.28.

[0120] Comparative Example 5

[0121] Distillation is currently the main industrial technology for separating n- / isopentane. A paper published by Zhang Z et al. (AIChEJ., 2020, 66(7): 16236-16243.) outlines a C5 fractionation unit with a production capacity of 100,000 kilotons per year and the production process using this unit. Table 5 shows a comparison of the specific parameters with the water-based adsorption slurry and liquid-phase separation method provided in Example 1 of this invention.

[0122] Table 5

[0123] Comparative Example 6

[0124] Similarly, Li et al. reported a method for gas-phase separation of pentane mixtures using ZIF-8 / DMPU slurry (Sep. Purif. Technol. 2023, 310, 123203.). Table 6 shows a comparison of specific parameters with the water-based adsorption slurry and liquid-phase separation method provided in Example 1 of this invention. Although the optimal separation factor for gas-phase separation is higher, based on overall technical and economic indicators and environmental factors, the water-based adsorption slurry and liquid-phase separation method of this invention has stronger prospects for industrial application.

[0125] Table 6

[0126] The above description is merely a specific embodiment of the present invention and should not be construed as limiting the scope of the invention. Therefore, any substitution of equivalent components or equivalent changes and modifications made within the scope of protection of this patent should still fall within the scope of this patent. Furthermore, the technical features, technical features and technical inventions, and technical inventions in this invention can be freely combined and used.

Claims

1. A water-based adsorption slurry, characterized in that, Based on the total weight of the water-based adsorption slurry as 100%, it comprises: 5-40% hydrophobic solid adsorbent; 0.1-2% nonionic surfactant; 0.01-1% defoamer; And the remaining deionized water; The hydrophobic solid adsorbent includes one or a combination of several of the following: metal-organic framework materials, porous silicate materials, carbonaceous adsorbents, and zeolites.

2. The water-based adsorption slurry according to claim 1, characterized in that, The metal-organic framework material is a ZIF series metal-organic framework material, including one or a combination of ZIF-8, ZIF-67 and ZIF-71.

3. The water-based adsorption slurry according to claim 1 or 2, characterized in that, The nonionic surfactant includes one or a combination of several of the following: polysorbates, polyoxyethylene fatty acid ethers, polyoxyethylene fatty acid esters, and alkylphenol polyoxyethylene ethers.

4. The water-based adsorption slurry according to claim 1 or 2, characterized in that, The defoamer includes one or a combination of several of the following: organosilicon, polyether-modified silicone, and polyether defoamers.

5. The method for preparing the water-based adsorption slurry according to any one of claims 1-4, characterized in that, The preparation method includes: The hydrophobic solid adsorbent, nonionic surfactant, defoamer and deionized water are mixed evenly until a stable solid-liquid suspension is formed, thus obtaining the water-based adsorption slurry.

6. The preparation method according to claim 5, characterized in that, The uniform mixing is achieved by mechanical stirring at room temperature; Preferably, the uniform mixing is achieved by mechanical stirring at room temperature and ultrasonic dispersion treatment.

7. A method for liquid-phase separation of near-boiling-point light hydrocarbon mixtures, characterized in that, The adsorbent used in the liquid phase separation method is the water-based adsorption slurry as described in any one of claims 1-4.

8. The liquid phase separation method according to claim 7, characterized in that, The liquid phase separation method specifically includes: Adsorption stage: The water-based adsorption slurry is mixed with the near-boiling light hydrocarbon mixture to be separated and stirred at the adsorption temperature to promote mass transfer. Liquid-solid separation stage: After adsorption reaches equilibrium, the mixture of water-based adsorption slurry and near-boiling light hydrocarbon mixture is centrifuged to obtain three-phase products: the supernatant is the remaining adsorption product, the lower liquid is a mixture of deionized water, nonionic surfactant and defoamer, and the precipitate is a hydrophobic solid adsorbent enriched with the adsorption phase. Desorption stage: The precipitate is heated to the desorption temperature and desorbed under vacuum conditions. After the desorbed gas is cooled and condensed, the adsorbed phase is obtained, thus completing the liquid phase separation of the near-boiling point light hydrocarbon mixture.

9. The liquid phase separation method according to claim 7 or 8, characterized in that, The near-boiling point light hydrocarbon mixture includes light hydrocarbon mixtures with a boiling point difference of less than 20°C; Preferably, the near-boiling point light hydrocarbon mixture includes a mixture of olefins and alkanes, a mixture of straight-chain hydrocarbons and branched-chain hydrocarbons, or a mixture of cyclic hydrocarbons and alkanes; More preferably, the near-boiling point light hydrocarbon mixture includes a mixture of C5 hydrocarbon isomers or a mixture of C6 hydrocarbon isomers; More preferably, the C5 hydrocarbon isomer mixture includes a combination of two or more of n-pentane, isopentane, cyclopentane, 1-pentene, 2-pentene and cyclopentene, and even more preferably a mixture of n-pentane and isopentane or a mixture of n-pentane and cyclopentane. More preferably, the mixture of C6 hydrocarbon isomers includes a combination of two or more of the following: n-hexane, 2-methylpentane, 3-methylpentane, 2,2-dimethylbutane, 2,3-dimethylbutane, cyclohexane, methylcyclopentane, 1-hexene, and 2-hexene. More preferably, it is any one of the following: a mixture of n-hexane and methylcyclopentane, a mixture of n-hexane and 2-methylpentane, or a mixture of n-hexane and 3-methylpentane.

10. The liquid phase separation method according to claim 9, characterized in that, The adsorption temperature is 15-30℃; the adsorption time is 10-120 min; the desorption temperature is 60-180℃; the desorption pressure is 0.1-5 kPa; and the desorption time is 30-120 min. Preferably, when the near-boiling point light hydrocarbon mixture is a mixture of C5 hydrocarbon isomers: The adsorption temperature is 15-30℃; The adsorption time is 40-90 min; The desorption temperature is 60-110℃; The desorption pressure is 0.1-5 kPa; The desorption time is 30-60 minutes; The volume ratio of the water-based adsorption slurry to the C5 hydrocarbon isomer mixture is 1-30:1, preferably 5-10:1; Preferably, when the near-boiling point light hydrocarbon mixture is a mixture of C6 hydrocarbon isomers: The adsorption temperature is 15-30℃; The adsorption time is 10-90 min; The desorption temperature is 90-150℃; The desorption pressure is 0.1-5 kPa; The desorption time is 30-120 min; The volume ratio of the water-based adsorption slurry to the C6 hydrocarbon isomer mixture is 1-30:1, preferably 5-10:1.

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