Feedstock refining apparatus and method

Abstract

The application discloses a raw material refining device, which comprises a raw material storage tank, at least one deoxygenation tower, at least one dehydration tower and a refined raw material storage tank which are sequentially communicated; the bottom outlet of the raw material storage tank is communicated with the bottom inlet of the deoxygenation tower through a pipeline provided with a flow control element; the top outlet of the deoxygenation tower is communicated with the bottom inlet of the dehydration tower through a pipeline provided with a preheating device; the top outlet of the dehydration tower is communicated with the top inlet of the refined raw material storage tank through a pipeline provided with an on-line water analyzer and a flow control element in sequence; and the top of the refined raw material storage tank, the deoxygenation tower and the dehydration tower is respectively provided with a low-pressure nitrogen gas pipeline. The raw material refining device is simple in operation, good in refining effect, high in flexibility and capable of separately performing dehydration treatment, separately performing deoxygenation treatment or sequentially performing deoxygenation and dehydration treatment. Nitrogen protection is performed through the low-pressure nitrogen gas pipeline, so that blockage can be avoided and the stability and safety of the device are improved.

Description

Technical Field

[0001] This invention relates to the field of raw material refining technology, and in particular to a raw material refining apparatus and method. Background Technology

[0002] Low-pressure polyethylene (LDPE) processes are primarily used to produce LLDPE (linear low-density polyethylene) and HDPE (high-density polyethylene). In terms of implementation methods, they are divided into three types: slurry process, solution process, and gas-phase process. In the slurry process, the polymer is in a suspended state and does not dissolve in hydrocarbon diluents; in the solution process, the polymer is dissolved in a solvent; and in the gas-phase process, the polymer exists as solid particles in a stirred bed or fluidized bed. The biggest advantage of the solution process is its short product changeover time, low gel content in the membrane material, and ability to produce a full range of products (from narrow to wide molecular weight distributions) as well as very low-density polyethylene (VLDPE, such as PE plasmids and elastomers). Furthermore, it can copolymerize with higher α-olefins, exhibiting excellent strength, toughness, and sealing properties.

[0003] Polyolefin elastomers (POEs) are random copolymer elastomers formed by the polymerization of ethylene and high-carbon α-olefins (1-butene, 1-hexene, 1-octene, etc.) under the action of a homogeneous metal catalyst, with octene having a mass fraction greater than 20%. Their unique structure gives POE the high elasticity of rubber at room temperature and allows for plastic molding at high temperatures. The unique structure formed by ethylene and octene endows POE with excellent mechanical properties, good corrosion resistance, and excellent rheological properties. Furthermore, POE has good affinity with polyolefin materials, effectively enhancing low-temperature toughness and offering high cost-effectiveness. Therefore, it is widely used in petrochemicals, wire and cable, automotive parts, daily necessities, hot melt adhesives, photovoltaics, and other fields. The application of POE has greatly impacted traditional rubber and plastic materials. Due to its superior properties, it has attracted extensive research and focus from researchers in the plastics field, and has thus received widespread attention from both academia and industry.

[0004] As a thermoplastic elastomer, POE possesses the dual properties of both plastics and rubber. Compared to other toughening agents such as EPDM, EPR, SBR, and EVA, POE exhibits the following characteristics: 1) A narrow molecular weight distribution and dense short-chain distribution, resulting in excellent mechanical properties (high elasticity, high strength, high elongation) and good low-temperature performance; 2) POE molecular chains are saturated, containing relatively few tertiary carbon atoms, leading to excellent UV resistance and heat aging resistance; 3) The narrow molecular weight distribution makes it less prone to deformation during extrusion and injection molding; 4) Using metallocene catalysts with defined geometries allows for the controlled introduction of long branches into the linear short-chain branched structure of POE, thereby improving its processing performance. Furthermore, it also possesses excellent light transmittance, electrical insulation, water vapor barrier properties, and outstanding weather resistance and PID resistance, and is gradually replacing EVA in photovoltaic encapsulation films in many applications.

[0005] However, when using solution-based processes to produce copolymers of ethylene and higher α-olefins, strict requirements are placed on the water and oxygen content of the liquid chemical raw materials used in the production process. For example, in the olefin polymerization process, monomers are mixed with organic solvents, and then a catalyst is added to initiate the polymerization of comonomers to form polymer chains. When the catalyst comes into contact with water, the metal contained in the catalyst will aggregate, causing crystal deformation and altering the catalyst's shape, thus damaging its activity and stability, and severely affecting the polymerization process and the quality and yield of the product. Moreover, if the oxygen content of the system is too high, the catalyst's structure will be damaged when it comes into contact with oxygen, leading to a significant decrease in the catalyst's catalytic performance. Therefore, before the reaction, the liquid chemical raw materials, including the organic solvent, need to undergo dehydration and appropriate deoxygenation treatment. Factors affecting the water removal efficiency from organic solvents mainly include: the selection of dehydration process, dehydration equipment, dehydration temperature, dehydration pressure, the residence time of the solvent in the dehydration medium, the type of solvent to be dehydrated, the type of drying adsorbent, and the initial water content, etc. Currently, methods to improve dehydration efficiency mainly include: increasing the residence time of the aqueous solvent in the dehydration device; increasing the contact area between the water in the solvent and the desiccant; and preventing the product from absorbing water again after dehydration.

[0006] Currently, existing raw material refining methods and equipment in laboratory and industrial applications mainly include sodium reflux refining, centrifugal refining, and traditional distillation column refining. Sodium reflux refining utilizes the exothermic reaction between metallic sodium and moisture in the raw material to produce sodium hydroxide and hydrogen gas, thereby removing moisture. However, the sodium used in this method is an alkali metal, which is easily oxidized and spontaneously combustible in air. The combustion produces sodium oxide-containing fumes that are highly corrosive and irritating to humans. Refining with sodium reflux is also prone to combustion and explosion, posing a significant danger. Centrifugal refining uses equipment consisting of a bed column, feed distribution device, heating furnace, condenser, and product collection device. It utilizes centrifugal force to enhance gas-liquid mass transfer, thereby achieving the separation and purification of organic solvents. However, centrifugal refining technology heavily relies on expensive proprietary equipment, increasing refining costs. Traditional distillation column purification utilizes the different volatility of the components in the feedstock, that is, the different vapor pressures of the components at the same temperature, to transfer the lighter components (low-boiling substances) in the liquid phase to the gas phase, while the heavier components (high-boiling substances) in the gas phase are transferred to the liquid phase, thereby achieving the purpose of purification. However, the operation is complicated and lacks flexibility.

[0007] To address the aforementioned issues, technicians have improved existing raw material refining devices or systems. For example, Chinese patent document CN1600756A discloses a method and apparatus for refining advanced α-olefin polymer monomers. In an air-isolated environment, liquid advanced α-olefin polymer monomers are forced from a raw material storage tank upwards into a set of molecular sieve adsorption columns at a speed of 0.05–0.1 m / s using room-temperature nitrogen gas. After passing a trace moisture test, the liquid is stored in a refined raw material storage tank. The molecular sieve adsorption columns are heated to 350–400°C by a nitrogen heater and fed into the columns at a pressure of 2 atmospheres. The outlet temperature reaches 120°C and is maintained for 2–3 hours. Nitrogen gas supply is then stopped, and the columns are allowed to cool naturally, regenerating the adsorption columns. However, this method only dehydrates and refines the olefin polymer monomers, failing to deoxygenate them. Furthermore, using nitrogen to force the olefin raw material into the adsorption columns makes precise control of the raw material refining flow rate difficult.

[0008] Chinese patent document CN205556503U discloses a solvent refining system, including a solvent refining tower, a heat exchanger, and a water-cutting tank. The solvent refining tower's inlet is connected to a solvent pipeline, and the heat exchanger connects the gas phase inlet and reflux outlet of the tower. The tower is connected to a reboiler via a reboiler liquid phase inlet and outlet, and the refined solvent is output from the tower bottom outlet. The system utilizes the characteristic that hydrocarbons, due to their different boiling points, can be separated from the solvent to refine the solvent. However, this system has poor solvent refining effect, is complex to operate, and has low flexibility.

[0009] Chinese patent document CN104262075A discloses a heating system for isoprene monomer refining, including an isoprene refining tower and a solvent refining tower. The isoprene refining tower is connected to an isoprene reboiler via pipeline, and the solvent refining tower is connected to the solvent reboiler via pipeline. The solvent reboiler is connected to a steam device via pipeline, and the steam condensate outlet of the solvent reboiler is connected to the inlet of a steam condensate tank via pipeline. The steam condensate tank is connected to a regulating liquid device via pipeline, and the outlet of the steam condensate tank is connected to the inlet of the isoprene reboiler via pipeline. However, in this scheme, isoprene monomers are prone to self-polymerization during the refining process of isoprene by steam heating, resulting in a high isoprene monomer loss rate, and the isoprene refining tower is prone to clogging.

[0010] Chinese patent document CN107774083A discloses a purification method for deep dehydration and impurity removal of olefins through full-temperature adsorption extraction. Crude olefin feedstock (gas or liquid) sequentially enters a gas / liquid phase adsorption process, an extraction-desorption process, and an extractant regeneration process. Moisture and trace impurities are adsorbed by the adsorbent, and olefin product with a purity greater than or equal to 99.9%–99.99% (v / v) flows out from the top of the adsorption tower. After the adsorption step, an extractant is introduced into the adsorption tower for the extraction-desorption process to dissolve water and trace impurities. The extracted and desorbed gas enters the extractant regeneration process to recover the extractant, which is then treated and recycled. However, this process, which uses extraction for adsorption treatment, requires the use of critical or supercritical extractants and extractant removal, making the process complex.

[0011] Chinese patent document CN113233951A discloses a production apparatus and process for selective oligomerization of ethylene into linear α-olefins, belonging to the field of homogeneous catalysis technology. The apparatus includes a raw material pretreatment unit, a reaction unit, and a separation unit. The reaction unit comprises a reactor, a circulating fan, a primary condenser, a primary condensate tank, a secondary condenser, and a secondary condensate tank, all connected sequentially. The primary condensate tank is connected to the separation unit; the secondary condensate tank is connected to the reactor. A temperature sensor is installed inside the reactor, and a gas regulating valve is installed between the primary condenser and the circulating fan. The gas regulating valve is interlocked with the temperature sensor, and the opening of the regulating valve is controlled by the temperature of the reactor. However, this method does not elaborate on the dehydration and deoxygenation apparatus and the dehydration and deoxygenation method.

[0012] Chinese patent document CN205867656U discloses an organic solvent dehydration device, including a storage tank and a dryer. The bottom of the storage tank is connected to the top of the dryer via a feed pipe. The dryer includes a drying barrel, a desiccant disposed inside the drying barrel, and a filter element. The top of the drying barrel is equipped with a quick-opening cover, and a sealing element is provided between the quick-opening cover and the drying barrel. A flip-up support is provided on the outside of the drying barrel, and a quick-connect fitting is provided at the bottom of the drying barrel. The quick-connect fitting is connected to a discharge pipe and a circulation pipe, respectively. The circulation pipe is connected to the top of the storage tank, and a sampling port is provided on the feed pipe. Although removing moisture through a dryer greatly reduces energy consumption, the need to frequently replace the desiccant to ensure the dehydration process continues is not economical or environmentally friendly. Furthermore, to determine whether the dehydration standard has been met, a sample must be taken from the bottom of the tower for testing, which can lead to deviations in the test results.

[0013] Chinese patent document CN216738132U discloses a metallocene polypropylene raw material refining device. The refining towers of this device sequentially include a desulfurization tower (1), a drying tower (2), a de-alcoholization tower (3), a dechlorination tower (4), a deoxygenation tower (5), a CO removal tower (6), an arsenic removal tower (7), and a CO2 removal tower (8). Crude propylene from the refinery is fed into the metallocene polypropylene raw material refining device for processing. While this device can remove impurities such as water, oxygen, carbon monoxide, carbon dioxide, alcohols, chlorides, sulfides, and arsenides from refinery propylene to the ppb level (10⁻⁹), fully meeting the requirements of metallocene catalysts, it relies on large-scale industrial equipment, lacks flexible switching and operation, has high energy and material consumption, a limited material processing range, and poor economic practicality. Summary of the Invention

[0014] The purpose of this invention is to provide a raw material refining apparatus and method to solve the problems of poor refining effect, easy blockage of apparatus and pipelines, complex and cumbersome process, high cost and high risk in the existing raw material refining apparatus and method.

[0015] To achieve the above objectives, the present invention provides a raw material refining apparatus, comprising a raw material storage tank, at least one deoxidation tower, at least one dehydration tower, and a refined raw material storage tank connected in sequence.

[0016] The bottom outlet of the raw material storage tank is connected to the bottom inlet of the deoxygenation tower via a pipeline equipped with a flow control element.

[0017] The top outlet of the deoxygenation tower is connected to the bottom inlet of the dehydration tower via a pipeline equipped with a preheating device.

[0018] The top outlet of the dehydration tower is connected to the top inlet of the refined raw material storage tank via a pipeline that is sequentially equipped with an online water analyzer and a flow control element.

[0019] The top of the refined raw material storage tank, the deoxygenation tower, and the dehydration tower are respectively equipped with low-pressure nitrogen pipelines, so that nitrogen protection is achieved throughout the raw material refining process to avoid the risk of material overheating and overpressure.

[0020] Optionally, in the above-mentioned raw material refining device provided by the present invention, the number of deoxygenation towers and dehydration towers can be set according to the actual situation. For example, a single tower (single deoxygenation tower, single dehydration tower), multiple towers in parallel (at least two deoxygenation towers in parallel, at least two dehydration towers in parallel), or multiple towers in series (at least two deoxygenation towers in series, at least two dehydration towers in series) can be set.

[0021] Optionally, in the raw material refining apparatus provided by the present invention, the top outlet of the dehydration tower is connected to the bottom inlet of the dehydration tower via a circulation pipeline; preferably, a circulation pump and a regulating element are provided on the circulation pipeline. When the water content in the raw material after dehydration in the dehydration tower does not meet the standard, the raw material can be reintroduced into the dehydration tower through the circulation pipeline for further dehydration treatment.

[0022] Optionally, in the above-mentioned raw material refining device provided by the present invention, the deoxidation tower is provided with a cavity, and the cavity is provided with deoxidation packing material, such as Raschig rings, Pall rings, etc.

[0023] Optionally, in the above-mentioned raw material refining device provided by the present invention, the dehydration tower has an internal cavity, and the cavity has a tower plate filled with a dehydrating agent. The dehydrating agent is regenerated by self-heating, so there is no need to replace the dehydrating agent. The dehydrating agent can be conventional in the industry, such as molecular sieve, alumina, etc.

[0024] Optionally, in the above-mentioned raw material refining apparatus provided by the present invention, the raw material storage tank, the deoxidation tower and the refined raw material storage tank are respectively equipped with pressure detection elements and / or temperature detection elements. The pressure detection elements and the temperature detection elements are used to monitor the pressure and temperature in each device at any time. Conventional materials in the industry can be used, such as pressure gauges, pressure thermometers, etc.

[0025] Optionally, in the above-mentioned raw material refining apparatus provided by the present invention, a vacuum pump is provided on the outer side of the top of the deoxygenation tower to maintain the vacuum environment of the system during the deoxygenation refining process of the deoxygenation tower.

[0026] Optionally, in the raw material refining apparatus provided by the present invention, the bottom outlet of the refined raw material storage tank, the top outlet of the dehydration tower, and the top outlet of the deoxidation tower are respectively connected to the top inlet of the raw material storage tank via a reflux pipeline; preferably, the reflux pipeline is equipped with a regulating element. By setting up the reflux pipeline, the material in the dehydration tower and the deoxidation tower can be controlled to flow back to the raw material storage tank through the regulating element set on the reflux pipeline, preventing potential risks to continuous refining due to equipment failure.

[0027] Optionally, in the raw material refining apparatus provided by the present invention, the bottom outlet of the raw material storage tank is connected to the bottom inlet of the dehydration tower via a pipeline equipped with a flow control element and a preheating device. When the raw material to be processed does not require deoxygenation treatment, it can be directly fed from the raw material storage tank into the dehydration tower for dehydration treatment.

[0028] Optionally, in the raw material refining apparatus provided by the present invention, the top outlet of the deoxidation tower is connected to the refined raw material storage tank or the feed pipeline via a pipeline equipped with a regulating element. When the raw material to be processed does not require dehydration, the deoxidized raw material can be directly input into the refined raw material storage tank or the feed pipeline of the reaction device.

[0029] Optionally, in the raw material refining apparatus provided by the present invention, the flow control element is used to precisely control the flow rate and speed of the raw material, and can be a conventional one used in the industry, such as a flow control pump. The regulating element is used to regulate the flow rate and pressure of the raw material, and can be a conventional one used in the industry, such as a regulating valve. The preheating device is used to heat the material, such as a preheater.

[0030] Optionally, in the above-mentioned raw material refining device provided by the present invention, each pipeline can be equipped with corresponding auxiliary components, such as regulating valves, according to actual needs.

[0031] The present invention also provides a method for refining raw materials, using the above-mentioned raw material refining apparatus, comprising the following steps:

[0032] Nitrogen gas is introduced into the low-pressure nitrogen pipeline. Then, the raw material to be refined in the raw material storage tank enters the deoxidation tower from the bottom inlet via a flow control element for deoxidation. The deoxidized raw material flows out from the top outlet of the deoxidation tower, is heated by a preheating device, and then enters the dehydration tower for dehydration. The dehydrated raw material is discharged from the top outlet of the dehydration tower. After passing the online water analyzer test, it enters the refined raw material storage tank; or

[0033] Nitrogen gas is introduced into the low-pressure nitrogen pipeline, and then the raw material to be refined in the raw material storage tank enters the deoxidation tower from the bottom inlet through the flow control element for deoxidation; the deoxidized raw material flows out from the top outlet of the deoxidation tower and enters the refined raw material storage tank or feed pipeline; or

[0034] Nitrogen gas is introduced into the low-pressure nitrogen pipeline. Then, the raw material to be refined in the raw material storage tank enters the dehydration tower from the bottom inlet of the dehydration tower through the flow control element and the preheating device for dehydration. The dehydrated raw material is discharged from the top outlet of the dehydration tower. After being tested and found to meet the standards by the online water analyzer, it enters the refined raw material storage tank.

[0035] Optionally, in the above-mentioned raw material refining method provided by the present invention, when the moisture content of the dehydrated raw material detected by the online water analyzer is not up to standard, the dehydrated raw material is re-entered into the dehydration tower through a circulation pipeline for further dehydration.

[0036] Optionally, in the above-mentioned raw material refining method provided by the present invention, the dehydration or deoxygenation steps can be omitted according to the actual characteristics of the raw material to be processed. The deoxygenated raw material can be directly input into the refining raw material storage tank or the feed pipeline, or the raw material to be processed in the raw material storage tank can be directly fed into the dehydration tower through the pipeline equipped with flow control element and preheating device and the bottom inlet of the dehydration tower for dehydration treatment.

[0037] Optionally, in the above-mentioned raw material refining method provided by the present invention, the parameters of the deoxygenation tower and the dehydration tower are not specifically limited. Conventional parameters in the industry can be adopted and then adjusted according to the actual situation. For example, the material can be heated to 30-200°C and then dehydrated by passing through the inner cavity of the dehydration tower plate at a linear velocity of 0.5-20 ml / min.

[0038] The above-mentioned raw material refining apparatus and raw material refining method provided by the present invention are applicable to various organic solvents and polymerization monomers required for different polymerization reactions. Preferably, the organic solvent is selected from at least one of aliphatic hydrocarbon solvents, alcohol solvents, fatty acid ester solvents, ketone solvents, haloalkyl solvents and benzene solvents. More preferably, the alcohol solvent is selected from at least one of methanol, ethanol, isopropanol, and n-butanol; the fatty acid ester solvent is selected from at least one of methyl acetate, ethyl acetate, propyl acetate, and butyl acetate; the ketone solvent is selected from at least one of acetone, butanone, methyl ethyl ketone, cyclohexanone, isopropanone, methyl butanone, methyl isobutyl ketone, methyl isobutyl ketone, methyl ethyl ketone, methyl pentanone, and cyclohexanone; the haloalkyl solvent is selected from at least one of dichloromethane, n-hexane, and 1,2-dichloroethane; the benzene solvent is selected from at least one of benzene, toluene, and xylene; and the aliphatic hydrocarbon solvent is selected from at least one of n-pentane, isopentane, methylcyclopentane, 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, 2,2-dimethylbutane, n-hexane, cyclohexane, n-heptane, and n-octane. More preferably, the polyolefin elastomer solvent is selected from at least one of n-pentane, isopentane, methylcyclopentane, 2-methylpentane, 3-methylpentane, 2,3-dimethylbutane, 2,2-dimethylbutane, n-hexane, cyclohexane, n-heptane, and n-octane. The polymerization monomer is selected from C5-C14 olefins, preferably one or more of 4-methyl-1-pentene, 1-hexene, and 1-octene.

[0039] Compared with the prior art, the present invention has the following advantages:

[0040] Beneficial Effect 1: The raw material refining device provided by this invention utilizes a deoxidation tower and a dehydration tower to sequentially refine the raw materials. It eliminates the need for complex specialized equipment and hazardous chemicals, effectively reducing the oxygen and water content in the raw materials. The device is simple to operate, provides excellent refining results, and avoids clogging of the equipment and pipelines. The deoxidizing materials and dehydrating agents used are inexpensive and readily available. By installing an online water analyzer, the refining status of the raw materials can be monitored in real time. Raw materials that do not meet the required standards are returned to the dehydration tower until the refining effect is satisfactory. This makes the device suitable for continuous polymerization reactions, improving raw material refining efficiency and reaction continuity. The installation of a low-pressure nitrogen pipeline provides full nitrogen protection, preventing clogging of the equipment and pipelines, avoiding the risk of material overheating and overpressure, and improving the stability and safety of the device. Combined with a refined raw material storage tank, material storage and refining can be carried out simultaneously during the refining process. The raw material refining device provided by this invention is suitable for refining various olefin polymerization monomers and organic solvents. By using this device to ensure that the water and oxygen content of the raw materials reaches the specified level before olefin polymerization, the polymerization activity of the catalyst and the quality of the product can be improved. It is especially suitable for solution-based continuous olefin polymerization processes.

[0041] Beneficial Effect 2: The raw material refining device provided by this invention can be adjusted at will according to actual usage needs, and the processing capacity of the device can be increased or decreased at will according to the raw material conditions. The specific number of deoxidation towers and dehydration towers can be set as a single tower or multiple towers in parallel or multiple towers in series, depending on the processing volume. Combined with online detection devices and multiple cycles of deoxidation and / or dehydration, it ensures that the raw materials meet the specifications required for polymerization experiments. Moreover, it has a wide range of applicable materials, low energy consumption, and meets the needs of both laboratory and industrial-scale devices, thus making it suitable for various types of continuous olefin polymerization processes.

[0042] Beneficial Effect 3: The raw material refining device provided by this invention is simple to operate and allows for flexible switching: it can use a dehydration tower for dehydration treatment alone; if the raw material water content meets the standard, it can also treat the oxygen content separately; and it can also perform deoxygenation and dehydration treatment sequentially. It is highly flexible and can meet the needs of different applications, ensuring refining effect while avoiding waste of refining costs. By setting up a return pipeline, flexible material return can be achieved. If, during the refining process, the environment inside the raw material storage tank tower cannot meet the feeding requirements or other unforeseen circumstances occur, the raw material can be returned from the top of each tower to the raw material storage tank for storage and further processing. Attached Figure Description

[0043] Figure 1 This is a schematic diagram of a raw material refining device provided by the present invention.

[0044] in:

[0045] 1. Raw material storage tanks;

[0046] 11. Low-pressure nitrogen pipeline;

[0047] 2. Flow control pump;

[0048] 3. Deoxygenation tower;

[0049] 31, 33, regulating valves;

[0050] 32. Vacuum pump;

[0051] 34. Low-pressure nitrogen pipeline;

[0052] 4. Preheater;

[0053] 5. Dehydration tower;

[0054] 51, 53, 54, regulating valves;

[0055] 52. Circulating pump;

[0056] 55. Low-pressure nitrogen pipeline;

[0057] 6. Online water analyzer;

[0058] 7. Refined raw material storage tanks;

[0059] 71, 72, 73, regulating valves;

[0060] 74. Low-pressure nitrogen pipeline;

[0061] 8. Feed pipeline. Detailed Implementation

[0062] The present invention will now be described in detail through embodiments. It should be noted that the following embodiments are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Those skilled in the art can make some non-essential improvements and adjustments to the present invention based on the above description.

[0063] In the description of this invention, it should be noted that the terms "top", "bottom" and "outer side" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limiting this invention.

[0064] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "connection" and "connection" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0065] To better illustrate the present invention, specific embodiments are described below, but these embodiments do not constitute a limitation of the present invention.

[0066] Example 1

[0067] This embodiment provides a raw material refining apparatus, including a raw material storage tank, at least one deoxidation tower, at least one dehydration tower, and a refined raw material storage tank connected in sequence.

[0068] The bottom outlet of the raw material storage tank is connected to the bottom inlet of the deoxidation tower via a pipeline equipped with a flow control element; the top outlet of the deoxidation tower is connected to the bottom inlet of the dehydration tower via a pipeline equipped with a preheating device; and the top outlet of the dehydration tower is connected to the top inlet of the refined raw material storage tank via a pipeline sequentially equipped with an online water analyzer and a flow control element.

[0069] Low-pressure nitrogen pipelines are installed at the top of the refined raw material storage tank, deoxygenation tower and dehydration tower to ensure nitrogen protection throughout the raw material refining process and avoid the risk of material overheating and overpressure.

[0070] The number of deoxygenation towers and dehydration towers can be set according to the actual situation. For example, a single tower (single deoxygenation tower, single dehydration tower), multiple towers in parallel (at least two deoxygenation towers in parallel, at least two dehydration towers in parallel), or multiple towers in series (at least two deoxygenation towers in series, at least two dehydration towers in series) can be set.

[0071] In one embodiment, the top outlet of the dehydration tower is connected to the bottom inlet of the dehydration tower via a circulation pipeline; in a preferred embodiment, the circulation pipeline is equipped with a circulation pump and a regulating valve. When the water content of the raw material after dehydration in the dehydration tower does not meet the standard, the raw material can be reintroduced into the dehydration tower through the circulation pipeline for further dehydration treatment.

[0072] In one embodiment, the deoxygenation tower has an internal cavity containing deoxygenation packing materials, such as Raschig rings or Pall rings.

[0073] In one embodiment, the dehydration tower has an internal cavity containing a tray filled with a dehydrating agent. The dehydrating agent can be a conventional one used in the industry, such as molecular sieve or alumina. The molecular sieve can be directly heated and regenerated inside the dehydration tower without the need for replacement, thus saving costs.

[0074] In one embodiment, the raw material storage tank, deoxidation tower, and refined raw material storage tank are respectively equipped with pressure detection elements and / or temperature detection elements. The pressure detection elements and temperature detection elements are used to monitor the pressure and temperature in each device at any time. Conventional industry-standard elements can be used, such as pressure gauges, temperature sensors, and pressure thermometers.

[0075] In one embodiment, a vacuum pump is provided on the outer side of the top of the deoxygenation tower to maintain a vacuum environment in the system during the deoxygenation and purification process.

[0076] In one embodiment, the bottom outlet of the refined raw material storage tank, the top outlet of the dehydration tower, and the top outlet of the deoxidation tower are connected to the top inlet of the raw material storage tank via reflux pipelines; in a preferred embodiment, the reflux pipeline is equipped with a regulating element. By setting up the reflux pipeline, the material in the dehydration tower and the deoxidation tower can be controlled to flow back to the raw material storage tank through the regulating element on the reflux pipeline, preventing potential risks to continuous refining due to equipment failure.

[0077] In one embodiment, the bottom outlet of the raw material storage tank is connected to the bottom inlet of the dehydration tower via a pipeline equipped with a flow control element and a preheating device. When the raw material to be processed does not require deoxygenation treatment, it can be directly fed into the dehydration tower from the raw material storage tank for dehydration treatment.

[0078] In one embodiment, the top outlet of the deoxidation tower is connected to a refined raw material storage tank or a feed line via a pipeline equipped with a regulating element. When the raw material to be processed does not require dehydration, the deoxidized raw material can be directly fed into the refined raw material storage tank or the feed line of the reaction unit.

[0079] The flow control components mentioned above are used to precisely control the flow rate and speed of the raw materials; standard industry-standard components, such as flow control pumps, are acceptable. The regulating components are used to regulate the flow rate and pressure of the raw materials; standard industry-standard components, such as regulating valves, are acceptable. The preheating device is used to heat the raw materials; standard industry-standard components, such as heaters, are acceptable.

[0080] Each of the pipelines mentioned above can be fitted with corresponding accessories, such as flanges, bolts, nuts, gaskets, elbows, tees, etc., according to actual needs.

[0081] Example 2

[0082] This embodiment provides a method for refining raw materials, employing... Figure 1 The raw material refining apparatus shown includes the following steps:

[0083] Open all valves on all pipelines within the entire unit. Then, open the valves on the low-pressure nitrogen pipeline 11 at the top of the raw material storage tank 1, the low-pressure nitrogen pipeline 34 at the top of the deoxidation tower 3, the low-pressure nitrogen pipeline 55 at the top of the dehydration tower 5, and the low-pressure nitrogen pipeline 74 at the top of the refined raw material storage tank 7, and purge each pipeline and unit with nitrogen gas to replace the air inside the unit and create a nitrogen atmosphere inside the entire unit. Then, keep the valves on each low-pressure nitrogen pipeline open at all times and close the valves on the remaining pipelines.

[0084] The raw material cyclohexane (water content 1560 ppm, oxygen content 1238 ppm) is introduced into the deoxidation tower 3 from the bottom outlet of the raw material storage tank 1 via the flow control pump 2 and the feed regulating valve 31 located at the bottom of the deoxidation tower 3 for deoxidation (during the deoxidation process, the vacuum pump 32 on the top outside of the deoxidation tower 3 is turned on to maintain the vacuum environment of the system during the deoxidation and purification process). The deoxidized cyclohexane is heated to 50°C by the preheater 4 located at the bottom inlet of the dehydration tower and then pumped into the dehydration tower 5, so that the cyclohexane... The cyclohexane is adsorbed and dehydrated by passing through the molecular sieve packed on the inner chamber plate of the dehydration tower 5 at a linear velocity of 10 ml / min. The dehydrated cyclohexane is discharged from the top outlet of the dehydration tower 5. The trace water content is detected by the online water analyzer 6 installed at the top outlet of the dehydration tower 5 and is 5 ppm, which meets the technical specifications. The regulating valve 71 is opened to discharge the dehydrated material into the refined raw material storage tank 7 for storage and later use, thus completing the refining process. The bottom outlet of the refined raw material storage tank 7 is connected to the feed pipeline 8, which is connected to the olefin polymerization unit.

[0085] The online water analyzer 6 is connected to the circulating pump 52 and the regulating valve 71 respectively. If the water content of the raw material discharged from the top of the dehydration tower 5 does not meet the requirements after being detected by the online water analyzer 6, the regulating valve 53 is opened. The material is then allowed to enter the dehydration tower 5 again from the bottom inlet of the dehydration tower 5 for circulating dehydration treatment (the dehydration tower 5, the online water analyzer 6, the circulating pump 52, the regulating valve 53 and the dehydration tower 5 form a circulation loop) until the water content meets the standard and then it is pumped into the refined raw material storage tank 7.

[0086] The deoxygenation packing in the deoxygenation tower is Raschig ring; the oxygen content of the refined cyclohexane in the refined raw material storage tank 7 was found to be 10 ppm.

[0087] If refining needs to be stopped due to malfunction or other reasons, open the regulating valve 33 on the top reflux pipeline of deoxidation tower 3, the regulating valve 54 on the top reflux pipeline of dehydration tower 5, and the regulating valve 73 at the bottom of refining raw material storage tank 7. The material in each unit will be returned to the raw material storage tank through the reflux pipelines of the top outlet of deoxidation tower, the top outlet of dehydration tower, and / or the bottom outlet of refining raw material storage tank.

[0088] Example 3

[0089] This embodiment provides a method for refining raw materials, employing... Figure 1 The raw material refining apparatus shown includes the following steps:

[0090] Open all valves on all pipelines within the entire unit. Then, open the valves on the low-pressure nitrogen pipeline 11 at the top of raw material storage tank 1, the low-pressure nitrogen pipeline 34 at the top of deoxygenation tower 3, the low-pressure nitrogen pipeline 55 at the top of dehydration tower 5, and the low-pressure nitrogen pipeline 74 at the top of refined raw material storage tank 7, and purge with nitrogen to replace the air in the unit and create a nitrogen atmosphere inside the entire unit. Then, keep the valves on low-pressure nitrogen pipeline 11 and low-pressure nitrogen pipeline 34 open at all times, and close the valves on low-pressure nitrogen pipeline 55, low-pressure nitrogen pipeline 74, and the remaining pipelines.

[0091] The raw material octene (with a water content of 8 ppm and an oxygen content of 744 ppm, requiring no dehydration treatment) enters the deoxidation tower 3 from the bottom outlet of the raw material storage tank 1 via the flow control pump 2 and the feed regulating valve 31 located at the bottom of the deoxidation tower 3 for deoxidation. The deoxidized octene then enters the feed pipeline sequentially through the top outlet of the deoxidation tower 3, regulating valve 51, and regulating valve 72. The feed pipeline 8 is connected to the olefin polymerization unit.

[0092] The deoxidation packing in the deoxidation tower is Raschig ring; the oxygen content of the refined octene in the refined raw material storage tank 7 was tested to be 7 ppm.

[0093] Example 4

[0094] This embodiment provides a method for refining raw materials, employing... Figure 1 The raw material refining apparatus shown includes the following steps:

[0095] Open all valves on all pipelines within the entire unit. Then, open the valves on the low-pressure nitrogen pipeline 11 at the top of raw material storage tank 1, the low-pressure nitrogen pipeline 34 at the top of deoxygenation tower 3, the low-pressure nitrogen pipeline 55 at the top of dehydration tower 5, and the low-pressure nitrogen pipeline 74 at the top of refined raw material storage tank 7, and purge with nitrogen to replace the air in the unit and create a nitrogen atmosphere inside the entire unit. Then, keep the valves on low-pressure nitrogen pipeline 11 and low-pressure nitrogen pipeline 55 open at all times, and close the valves on low-pressure nitrogen pipeline 34, low-pressure nitrogen pipeline 74, and the remaining pipelines.

[0096] The raw material to be refined, hexane (with a water content of 2560 ppm and an oxygen content of 10 ppm, requiring no deoxygenation treatment), enters from the bottom outlet of the raw material storage tank 1 through the flow control pump 2 and the regulating valve 51 into the preheater 4 located at the bottom inlet of the dehydration tower 5. After being heated to 35°C, it is pumped into the dehydration tower 5, where the hexane passes through the molecular sieve packed on the inner cavity of the dehydration tower 5 at a linear velocity of 8 ml / min for adsorption and dehydration. The dehydrated material is discharged from the top outlet of the dehydration tower 5. The trace water content is detected by the online water analyzer 6 located at the top outlet of the dehydration tower 5 and is 6 ppm, meeting the technical specifications. The regulating valve 71 is then opened to discharge the dehydrated material into the refined raw material storage tank 7 for storage and later use, thus completing the refining process. The bottom outlet of the refined raw material storage tank 7 is connected to the feed pipeline 8, which is connected to the olefin polymerization unit.

[0097] The online water analyzer 6 is connected to the circulating pump 52 and the regulating valve 71 respectively. If the water content of the raw material discharged from the top of the dehydration tower 5 does not meet the requirements after being detected by the online water analyzer 6, the regulating valve 53 is opened. The material is then allowed to enter the dehydration tower 5 again from the bottom inlet of the dehydration tower 5 for circulating dehydration treatment (the dehydration tower 5, the online water analyzer 6, the circulating pump 52, the regulating valve 53 and the dehydration tower 5 form a circulation loop) until the water content meets the standard and then it is pumped into the refined raw material storage tank 7.

[0098] As can be seen from Examples 2-4 above, the raw material refining device provided by this invention does not require complex special equipment or hazardous chemicals, and is simple to operate with flexible switching capabilities: it can use a dehydration tower for dehydration treatment alone; if the raw material water content meets the standard, it can also treat the oxygen content separately; and it can also perform dehydration and deoxygenation simultaneously, offering high flexibility to meet different application needs. It ensures refining effectiveness while avoiding waste of refining costs, and it will not cause blockages in the device or pipelines. By setting up a return pipeline, flexible material return can be achieved. If, during the refining process, the environment inside the refining raw material storage tank tower fails to meet the feeding requirements or other unforeseen circumstances occur, the raw material can be returned from the top of each tower to the raw material storage tank for storage and further processing.

[0099] Of course, the present invention may have other various embodiments. Without departing from the spirit and essence of the present invention, those skilled in the art can make various corresponding changes and modifications according to the present invention, but these corresponding changes and modifications should all fall within the protection scope of the claims of the present invention.

Claims

1. A raw material refining apparatus, characterized in that, It includes a raw material storage tank, at least one deoxygenation tower, at least one dehydration tower and a refined raw material storage tank connected in sequence; The bottom outlet of the raw material storage tank is connected to the bottom inlet of the deoxygenation tower via a pipeline equipped with a flow control element. The top outlet of the deoxygenation tower is connected to the bottom inlet of the dehydration tower via a pipeline equipped with a preheating device. The top outlet of the dehydration tower is connected to the top inlet of the refined raw material storage tank via a pipeline that is sequentially equipped with an online water analyzer and a flow control element. The top of the refined raw material storage tank, the deoxygenation tower, and the dehydration tower are respectively equipped with low-pressure nitrogen pipelines; The top outlet of the dehydration tower is connected to the bottom inlet of the dehydration tower via a circulation pipeline; The bottom outlet of the refined raw material storage tank, the top outlet of the dehydration tower, and the top outlet of the deoxygenation tower are respectively connected to the top inlet of the raw material storage tank via reflux pipelines. The bottom outlet of the raw material storage tank is connected to the bottom inlet of the dehydration tower via a pipeline equipped with a flow control element and a preheating device. The top outlet of the deoxidation tower is connected to the refined raw material storage tank or feed pipeline via a pipeline equipped with a regulating element.

2. The raw material refining apparatus as described in claim 1, characterized in that, The circulation pipeline is equipped with a circulation pump and regulating elements.

3. The raw material refining apparatus as described in claim 1, characterized in that, The deoxygenation tower has an internal cavity, and the cavity is filled with deoxygenation packing material.

4. The raw material refining apparatus as described in claim 1, characterized in that, The dehydration tower has an internal cavity, and the cavity contains a tray filled with a dehydrating agent.

5. The raw material refining apparatus as described in claim 1, characterized in that, The raw material storage tank, the deoxidation tower, and the refined raw material storage tank are respectively equipped with pressure detection elements and / or temperature detection elements.

6. The raw material refining apparatus as described in claim 1, characterized in that, A vacuum pump is installed on the outer top of the deoxygenation tower.

7. A method for refining raw materials, characterized in that, The raw material refining apparatus according to any one of claims 1-6 comprises the following steps: Nitrogen gas is introduced into the low-pressure nitrogen pipeline. Then, the raw material to be refined in the raw material storage tank enters the deoxygenation tower from the bottom inlet of the deoxygenation tower through the flow control element for deoxygenation. The deoxygenated raw material flows out from the top outlet of the deoxygenation tower, is heated by the preheating device, and then enters the dehydration tower for dehydration. The dehydrated raw material is discharged from the top outlet of the dehydration tower. After being tested by the online water analyzer and meeting the standards, it enters the refined raw material storage tank. or Nitrogen gas is introduced into the low-pressure nitrogen pipeline, and then the raw material to be refined in the raw material storage tank enters the deoxidation tower from the bottom inlet of the deoxidation tower through the flow control element for deoxidation; the deoxidized raw material flows out from the top outlet of the deoxidation tower and enters the refined raw material storage tank or feed pipeline. or Nitrogen gas is introduced into the low-pressure nitrogen pipeline. Then, the raw material to be refined in the raw material storage tank enters the dehydration tower from the bottom inlet of the dehydration tower through the flow control element and the preheating device for dehydration. The dehydrated raw material is discharged from the top outlet of the dehydration tower. After being tested and found to meet the standards by the online water analyzer, it enters the refined raw material storage tank.

8. The raw material refining method as described in claim 7, characterized in that, When the moisture content of the dehydrated raw material detected by the online water analyzer is not up to standard, the dehydrated raw material is re-entered into the dehydration tower through the circulation pipeline for further dehydration.

Images