Preparation device and preparation method of high-softening-point asphalt

Abstract

The invention discloses a preparation device and a preparation method of high-softening-point asphalt, and belongs to the technical field of coal chemical industry. The liquid preparation unit is provided with an asphalt inlet, a solvent oil inlet and an asphalt solution outlet; the tangential flow filtering unit is provided with a total asphalt solution inlet, a total concentrated solution outlet and a total washing and filtering solution outlet; the total asphalt solution inlet is communicated with the asphalt solution outlet and is used for intercepting and separating high-softening-point asphalt with the weight-average molecular weight being greater than or equal to 450 from the asphalt solution to form a concentrated solution containing the high-softening-point asphalt and washing filtrate; the concentrated solution treatment unit is provided with a total concentrated solution inlet, a high-softening-point asphalt outlet and a first solvent oil outlet; the concentrated solution total outlet is communicated with the concentrated solution total inlet and is used for separating high-softening-point asphalt and first solvent oil; the washing filtrate treatment unit is provided with a washing filtrate total inlet, a low-softening-point asphalt outlet and a second solvent oil outlet; and the washing filtrate total outlet is communicated with the washing filtrate total inlet. The method is environment-friendly, simple in process and low in energy consumption.

Description

Technical Field

[0001] This application relates to the technical field of coal chemical engineering, and more specifically, to an apparatus and a method for preparing high softening point pitch. Background Art

[0002] High softening point pitch, also known as high-carbon resin pitch material, usually has a softening point above 220°C and has excellent high-temperature resistance, so it has been widely used. As an important engineering material, it can play roles such as plugging, anti-collapse, coating, and bonding under high-temperature conditions, such as being used in deep oil and gas field drilling fluids and building waterproofing; as a modification additive for polymer materials. In addition, it can also be used as a raw material for new carbon materials to prepare pitch-based carbon fibers, needle coke, foam carbon, high-end activated carbon, etc. for lithium battery anode materials, and the market demand is very large.

[0003] Currently, there are mainly the following three processes for the production of high softening point pitch. The first is the oxidized pitch process, which uses vacuum residue with a low softening point, solvent-deasphalted oil, or a mixture of them as raw materials. Air is introduced into an oxidation tower for a long reaction of cross-linking polymerization under certain temperature conditions (usually 350 - 400°C, referring to the internal temperature of the pitch), so that its composition changes, the softening point increases, and the temperature sensitivity decreases to meet the requirements of the pitch product specifications and service performance. For example, the prior art discloses heating the pitch raw material to a molten state, mixing it with 0.01% - 5% of a reactant additive and air for pre-reaction, and then performing high-speed air blowing oxidation to obtain oxygen-containing high softening point pitch. The prior art also discloses that purified pitch without QI is used as an oxidant with oxygen in the air, and is modified through a three-stage kettle oxidation process at a temperature of 150 - 350°C, and then filtered and cooled and formed to obtain pitch with a softening point of 220 - 295°C. The prior art also discloses adding low-QI high-purity impregnating pitch into a stirring reaction kettle, introducing air and nitrogen, and performing air oxidation at 180 - 330°C for 10 - 30 hours. The obtained product is fed into a scraper film evaporator for thin film distillation to remove light components, and high-purity oxygen-containing high softening point pitch with a softening point reaching 250 - 300°C is prepared; the prior art also discloses that the refined soft pitch raw material is subjected to vacuum distillation to remove low-boiling components, and then oxidized and vacuum thin film distilled to adjust the softening point to 250 - 280°C to obtain oxygen-containing high softening point spinnable pitch.

[0004] The second thermal polymerization process uses low softening point asphalt as raw material. Under the protection of inert gas, a long-term reaction thermal polymerization reaction is carried out under certain temperature conditions (usually at 350-400 °C), so that its composition changes and the softening point increases. The prior art discloses a method of adding aromatic light oil to raw material asphalt for extraction. After the extracted insoluble matter is mixed with aromatic middle oil and then mixed with the raw material asphalt and filtered, the filtrate is distilled to obtain an intermediate product asphalt, and the precursor asphalt with a softening point of about 240 °C is obtained after heat treatment of the intermediate asphalt. The prior art also discloses that coal liquefaction asphalt is crushed and put into a reaction kettle for melting, and inert gas is blown in. At a temperature of 200 °C to 360 °C, a heating polymerization reaction is carried out in stages to obtain a high softening point asphalt with a softening point of 200 °C to 300 °C.

[0005] The third cross-linking modification process is that low softening point asphalt and a cross-linking agent carry out a cross-linking polymerization reaction under the protection of inert gas, so that its composition changes and the softening point increases. The prior art discloses a method of using a carboxylic anhydride component containing a cyclic structure and high-purity asphalt, at a temperature of 200-370 °C, carrying out a cross-linking polymerization reaction in an inert atmosphere, and then obtaining high softening point asphalt through distillation.

[0006] However, in the above patents, the preparation process of high softening point asphalt mainly relies on intermittent kettle reactions, with too long reaction time and complex processes; at the same time, there are problems such as low oxidation efficiency and uneven product asphalt components; moreover, the reaction kettle is prone to uneven heating, and common problems such as mesophase and low product yield are likely to occur during high-temperature thermal polycondensation; in view of these problems, in the industrial production process, multi-stage reaction devices are mostly used, increasing the process complexity, high energy consumption, and more prone to coking, resulting in problems such as difficult discharging and post-treatment. In addition, these processes all have varying degrees of pollutant emissions during production, which is not conducive to environmental protection. Therefore, there is still a need to develop a production process with low energy consumption and environmental friendliness to produce high softening point asphalt with a reasonable molecular weight distribution. Summary of the Invention

[0007] The main purpose of this application is to provide a preparation device and a preparation method for high softening point asphalt to solve the problems of low product yield, complex process, easy coking, and environmental unfriendliness in the production process of high softening point asphalt in the prior art.

[0008] To achieve the above purpose, according to one aspect of this application, a preparation device for high softening point asphalt is provided, including: a liquid preparation unit, which has an asphalt inlet, a solvent oil inlet, and an asphalt solution outlet; the liquid preparation unit is used for mixing solvent oil raw materials and asphalt raw materials to obtain an asphalt solution;

[0009] Tangential flow filtration unit, having a total inlet for asphalt solution, a total outlet for concentrated solution and a total outlet for washing filtrate; the total inlet for asphalt solution is communicated with the asphalt solution outlet; the tangential flow filtration unit is used to intercept and separate high softening point asphalt with a weight average molecular weight ≥ 450 from the asphalt solution to respectively obtain a concentrated solution containing high softening point asphalt and a washing filtrate after interception and separation;

[0010] Concentrated solution treatment unit, having a total inlet for concentrated solution, an outlet for high softening point asphalt and an outlet for the first solvent oil; the total outlet for concentrated solution is communicated with the total inlet for concentrated solution; the concentrated solution treatment unit is used to separately separate high softening point asphalt and the first solvent oil from the concentrated solution;

[0011] Washing filtrate treatment unit, having a total inlet for washing filtrate, an outlet for low softening point asphalt and an outlet for the second solvent oil; the total outlet for washing filtrate is communicated with the total inlet for washing filtrate; the washing filtrate treatment unit is used to separately separate low softening point asphalt with a weight average molecular weight < 450 and the second solvent oil from the washing filtrate.

[0012] Furthermore, the tangential flow filtration unit includes a tangential flow filter, the tangential flow filter having a total inlet for asphalt solution, a concentrated solution outlet and a washing filtrate outlet; the tangential flow filter has a filter element, and the filter element is a nano membrane tube; along the tangential flow filtration direction of the asphalt solution, the nano membrane tube includes a filtration layer, a transition layer and a support layer which are sequentially stacked.

[0013] Furthermore, the pore size of the filtration layer is 0.5 - 20 nm; the pore size of the transition layer is 30 - 80 nm; the pore size of the support layer is 0.08 - 0.5 μm.

[0014] Furthermore, the pore size of the filtration layer is 2 - 10 nm; the pore size of the transition layer is 30 - 60 nm; the pore size of the support layer is 0.1 - 0.5 μm.

[0015] Furthermore, the weight average molecular weight of the high softening point asphalt is 450 - 1000.

[0016] Furthermore, the number of tangential flow filters ≥ 2; multiple tangential flow filters are connected in series in such a way that the concentrated solution outlet of the previous tangential flow filter is communicated with the asphalt solution inlet of the next tangential flow filter.

[0017] Furthermore, the tangential flow filter includes tangential flow filter A and tangential flow filter B; the concentrated solution outlet of tangential flow filter A is communicated with the asphalt solution inlet of tangential flow filter B.

[0018] Furthermore, a booster pump is also provided between tangential flow filter A and tangential flow filter B; the concentrated solution outlet of tangential flow filter A is communicated with the inlet of the booster pump, and the outlet of the booster pump is communicated with the asphalt solution inlet of tangential flow filter B.

[0019] Further, the nanofilm tube of the tangential flow filter A includes a first filtration layer, a first transition layer, and a first support layer that are sequentially stacked.

[0020] Further, the pore size of the first filtration layer is 2 - 5 nm, the pore size of the first transition layer is 30 - 40 nm, and the pore size of the first support layer is 0.1 - 0.3 μm.

[0021] Further, the nanofilm tube of the tangential flow filter B includes a second filtration layer, a second transition layer, and a second support layer that are sequentially stacked.

[0022] Further, the pore size of the second filtration layer is 6 - 10 nm, the pore size of the second transition layer is 50 - 60 nm, and the pore size of the third support layer is 0.35 - 0.5 μm.

[0023] Further, the tangential flow filtration unit further includes a concentrate pump and a wash filtrate pump; the concentrate outlet of the tangential flow filter is communicated with the inlet of the concentrate pump, the outlet of the concentrate pump is the total concentrate outlet, and the total concentrate outlet is communicated with the total concentrate inlet; the wash filtrate outlet of the tangential flow filter is communicated with the inlet of the wash filtrate pump, the outlet of the wash filtrate pump is the total wash filtrate outlet, and the total wash filtrate outlet is communicated with the total wash filtrate inlet.

[0024] Further, the tangential flow filtration unit further includes a concentrate storage tank and a wash filtrate storage tank; the concentrate outlet of the tangential flow filter is communicated with the inlet of the concentrate storage tank, the outlet of the concentrate storage tank is communicated with the inlet of the concentrate pump; the wash filtrate outlet of the tangential flow filter is communicated with the inlet of the wash filtrate storage tank, and the outlet of the wash filtrate storage tank is communicated with the inlet of the wash filtrate pump.

[0025] Further, the wash filtrate storage tank includes a wash filtrate storage tank A and a wash filtrate storage tank B; the wash filtrate outlet of the tangential flow filter A is communicated with the inlet of the wash filtrate storage tank A; the wash filtrate outlet of the tangential flow filter B is communicated with the inlet of the wash filtrate storage tank B; the outlets of the wash filtrate storage tank A and the wash filtrate storage tank B are respectively communicated with the wash filtrate pump.

[0026] Further, the liquid preparation unit includes a solution preparation tank and a feed pump; the solution preparation tank includes a first inlet and a second inlet; the outlet of the solution preparation tank is communicated with the inlet of the feed pump, the outlet of the feed pump is the asphalt solution outlet, and the asphalt solution outlet is communicated with the total asphalt solution inlet.

[0027] Further, the liquid preparation unit further includes a solvent oil storage tank and an asphalt storage tank; the solvent oil storage tank has a solvent oil inlet for feeding external solvent oil, and the outlet of the solvent oil storage tank is communicated with the first inlet of the solution preparation tank; the asphalt storage tank has an asphalt inlet for feeding external asphalt, and the outlet of the asphalt storage tank is communicated with the second inlet of the solution preparation tank.

[0028] Further, the concentrate outlet of the tangential flow filter communicates with the first inlet of the solution preparation tank.

[0029] Further, the solution preparation tank includes solution preparation tank A and solution preparation tank B; the outlet of the solvent oil storage tank communicates with the first inlet of solution preparation tank A and the first inlet of solution preparation tank B respectively; the outlet of the asphalt storage tank communicates with the second inlet of solution preparation tank A and the second inlet of solution preparation tank B respectively; the outlets of solution preparation tank A and solution preparation tank B communicate with the inlet of the feed pump respectively.

[0030] Further, the concentrate outlet of the tangential flow filter communicates with the first inlet of solution preparation tank A and the first inlet of solution preparation tank B respectively.

[0031] Further, the tangential flow filter includes tangential flow filter A and tangential flow filter B; the concentrate outlet of tangential flow filter A and the concentrate outlet of tangential flow filter B communicate with the first inlet of solution preparation tank A respectively; or, the concentrate outlet of tangential flow filter A and the concentrate outlet of tangential flow filter B communicate with the first inlet of solution preparation tank B respectively.

[0032] Further, the liquid preparation unit further includes a flushing pump; the tangential flow filtration unit further has a solvent flushing inlet; the inlet of the flushing pump communicates with the outlet of the solvent oil storage tank, and the outlet of the flushing pump communicates with the solvent flushing inlet.

[0033] Further, the concentrate treatment unit includes a first distillation column and a high softening point asphalt forming machine; the first distillation column has a total concentrate inlet, a first bottom outlet of the distillation column and a first solvent oil outlet; the first bottom outlet of the distillation column communicates with the inlet of the high softening point asphalt forming machine, and the high softening point asphalt outlet of the high softening point asphalt forming machine is used to send out the high softening point asphalt.

[0034] Further, the washing filtrate treatment unit includes a second distillation column and a low softening point asphalt forming machine; the second distillation column has a total washing filtrate inlet, a second bottom outlet of the distillation column and a second solvent oil outlet; the second bottom outlet of the distillation column communicates with the inlet of the low softening point asphalt forming machine, and the low softening point asphalt outlet of the low softening point asphalt forming machine is used to send out the low softening point asphalt.

[0035] Further, the preparation device further includes a cooling unit and a solvent oil buffer unit; the first solvent oil outlet and the second solvent oil outlet communicate with the inlet of the cooling unit respectively; the outlet of the cooling unit communicates with the inlet of the solvent oil buffer unit; the solvent oil storage tank also has a solvent oil return inlet; the outlet of the solvent oil buffer unit communicates with the solvent oil return inlet.

[0036] According to the second aspect of the present application, there is provided a method for preparing the above-mentioned high softening point asphalt, including the following steps:

[0037] Step S1: Mix solvent oil and asphalt to obtain an asphalt solution;

[0038] Step S2: Filter and separate the asphalt solution by tangential flow filtration to obtain a concentrate containing high softening point asphalt and a washing filtrate after cut-off separation; wherein, the molecular weight of the high softening point asphalt is ≥450;

[0039] Step S3: Perform the first distillation on the concentrate containing high softening point asphalt to obtain high softening point asphalt and the first solvent oil;

[0040] Step S4: Perform the second distillation on the washing filtrate after cut-off separation to obtain low softening point asphalt and the second solvent oil; wherein, the weight average molecular weight of the low softening point asphalt is <450; The preparation method is carried out in the above-mentioned preparation device.

[0041] Further, in step S1, the solvent oil is selected from at least one of tetrahydrofuran, toluene, pyridine, N-methylpyrrolidone, middle oil in coal liquefaction, and wash oil of coal tar.

[0042] Further, the asphalt is selected from at least one of coal liquefaction asphalt, coal tar modified asphalt, and petroleum modified asphalt.

[0043] Further, the weight ratio of the solvent oil to the asphalt is (1 - 3):1.

[0044] Further, the mixing temperature of the solvent oil and the asphalt is 80 - 130 °C.

[0045] Further, the viscosity of the asphalt solution is 100 - 300 cP.

[0046] Further, in step S2, the asphalt solution is pre-filtered before tangential flow filtration.

[0047] Further, the feed pressure of the asphalt solution in tangential flow filtration is 0.42 - 0.7 MPa.

[0048] Further, the tangential flow filtration is carried out under the condition of a temperature of 110 - 170 °C.

[0049] Further, the transmembrane pressure difference of each membrane layer of the nanometer membrane tube used in the tangential flow filtration is ≤0.38 MPa.

[0050] Further, the tangential flow filtration is multi-stage tangential flow filtration.

[0051] Further, in step S3, the conditions of the first distillation include: a temperature of 220 - 350 °C and a vacuum degree of 1 - 10 KPa.

[0052] Further, the molecular weight of the high softening point asphalt is 500 - 1000.

[0053] Further, the softening point of the high softening point asphalt is 220 - 260 °C.

[0054] Further, in step S4, the conditions for the second distillation include: the temperature is 220 - 350 °C, and the vacuum degree is 1 - 10 KPa.

[0055] Further, the softening point of the low softening point asphalt is 60 - 100 °C.

[0056] Further, in step S1, before the concentrated solution containing the high softening point asphalt undergoes the first distillation, it returns to step S1, and at the same time, a first new solvent oil is added to the asphalt solution. The flow rate of the first new solvent oil is the same as the flow rate of the washing filtrate without the high softening point asphalt.

[0057] Further, in step S2, the tangential flow filtration includes primary tangential flow filtration and secondary tangential flow filtration; the asphalt solution undergoes primary tangential flow filtration to obtain a primary concentrated solution and a primary washing filtrate respectively; the primary concentrated solution undergoes secondary tangential flow filtration to obtain a secondary concentrated solution and a secondary washing filtrate respectively; the secondary concentrated solution undergoes the first distillation to obtain high softening point asphalt and a first solvent oil respectively; the primary washing filtrate or the secondary washing filtrate undergoes the second distillation to obtain low softening point asphalt and a second solvent respectively.

[0058] Further, in step S3, before the secondary concentrated solution undergoes the first distillation, it returns to step S1, and at the same time, a second new solvent oil is added to the asphalt solution; the sum of the flow rates of the primary washing filtrate and the secondary washing filtrate is the same as the flow rate of the second new solvent oil.

[0059] Compared with the prior art, the present application has the following beneficial effects:

[0060] The high softening point asphalt preparation device provided by the present application adopts a tangential flow filtration unit, which can intercept and separate high softening point asphalt with a weight average molecular weight ≥ 450 from the asphalt solution, respectively forming a concentrated solution containing high softening point asphalt and a washing filtrate without high softening point asphalt; compared with using a traditional metal membrane tube, the filtration accuracy is higher, and the low molecular weight components in the asphalt can be removed to obtain high softening point asphalt, which provides a preparation method for high softening point modified asphalt that can operate for a long period; combined with the concentrated solution and washing filtrate distillation unit, high purity high softening point asphalt and high purity low softening point asphalt can be further obtained.

[0061] The method for preparing high softening point asphalt provided by this application is a physical separation method, which has simple process steps and low energy consumption. At the same time, in this method, there is no need for reactions such as heating polymerization or oxidation, avoiding problems such as mesophase and coking in the product caused by uneven heating. Moreover, no by-products, waste gas or waste water are generated during the production process of this method, achieving zero emissions and having no pollution to the environment. It is an environmentally friendly production method. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] The specification drawings forming a part of this application are used to provide a further understanding of this application. The schematic embodiments of this application and their descriptions are used to explain this application and do not constitute an improper limitation to this application. In the drawings:

[0063] Figure 1 It is a schematic diagram of the preparation device (primary filtration) of high softening point asphalt according to an embodiment of this application;

[0064] Figure 2 It is a schematic diagram of the preparation device (two-stage filtration) of high softening point asphalt according to an embodiment of this application;

[0065] Figure 3 It is a schematic diagram of the structure of the tangential flow filter according to an embodiment of this application.

[0066] Reference numerals:

[0067] 10, liquid preparation unit; 11, solvent oil storage tank; 12, asphalt storage tank; 13, solution preparation tank; 13A, solution preparation tank A; 13B, solution preparation tank B; 14, feed pump; 15, flushing pump; 20, tangential flow filtration unit; 21, tangential flow filter; 210, filter element; 211, filtration layer; 212, transition layer; 213, support layer; 21A, tangential flow filter A; 21B, tangential flow filter B; 211A, first filtration layer; 212A, first transition layer; 213A, first support layer; 211B, second filtration layer; 212B, second transition layer; 213B, second support layer; 214, booster pump; 21-E, total inlet of asphalt solution; 21-H, concentrated liquid outlet; 21-F, washing filtrate outlet;

[0068] 22, concentrated liquid storage tank; 23, concentrated liquid pump; 24, washing filtrate storage tank; 24A, washing filtrate storage tank A; 24B, washing filtrate storage tank B; 25, washing filtrate pump;

[0069] 30, concentrated liquid treatment unit; 31, first distillation tower; 32, high softening point asphalt forming machine;

[0070] 40, washing filtrate treatment unit; 41, second distillation tower; 42, low softening point asphalt forming machine;

[0071] 50, cooling unit;

[0072] 60. Solvent oil buffer unit. Specific embodiments

[0073] It should be noted that, without conflict, the embodiments in the present application and the features in the embodiments can be combined with each other. The present application will be described in detail below in conjunction with the embodiments.

[0074] As mentioned in the background art, the preparation process of high softening point asphalt mainly relies on intermittent kettle reactions, with long reaction times and complex processes. At the same time, there are problems such as low oxidation efficiency and uneven product asphalt components. Moreover, the reaction kettle is prone to uneven heating, and common problems such as mesophase and low product yield are likely to occur during high-temperature thermal polycondensation. To address these problems, in industrial production, multi-stage reaction devices are mostly used, increasing the process complexity, high energy consumption, and being more prone to coking, resulting in difficulties in discharging and post-treatment. In addition, these processes all have varying degrees of pollutant emissions during production, which is not conducive to environmental protection. Therefore, there is still a need to develop a production process with low energy consumption and environmental friendliness to produce high softening point asphalt with a reasonable molecular weight distribution.

[0075] According to one aspect of the present application, a preparation device for high softening point asphalt is provided, as Figure 1 shown, including:

[0076] A liquid preparation unit 10, having an asphalt inlet, a solvent oil inlet, and an asphalt solution outlet; the liquid preparation unit 10 is used to mix the solvent oil raw material and the asphalt raw material to obtain an asphalt solution;

[0077] A tangential flow filtration unit 20, having a total asphalt solution inlet, a concentrate total outlet, and a washing filtrate total outlet; the total asphalt solution inlet is connected to the asphalt solution outlet; the tangential flow filtration unit 20 is used to intercept and separate high softening point asphalt with a weight average molecular weight ≥ 200 from the asphalt solution to respectively obtain a concentrate containing high softening point asphalt and a washing filtrate after interception and separation;

[0078] A concentrate treatment unit 30, having a concentrate total inlet, a high softening point asphalt outlet, and a first solvent oil outlet; the concentrate total outlet is connected to the concentrate total inlet; the concentrate treatment unit 30 is used to separately separate high softening point asphalt and a first solvent oil from the concentrate;

[0079] A washing filtrate treatment unit 40, having a washing filtrate total inlet, a low softening point asphalt outlet, and a second solvent oil outlet; the washing filtrate total outlet is connected to the washing filtrate total inlet; the washing filtrate treatment unit 40 is used to separately separate low softening point asphalt with a weight average molecular weight < 200 and a second solvent oil from the washing filtrate.

[0080] The high softening point asphalt preparation device provided by this application adopts a tangential flow filtration unit. This device type can be selected from the prior art. Using the filtration principle of the tangential flow filtration unit, high softening point asphalt with a weight average molecular weight ≥ 200 can be intercepted and separated from the asphalt solution, respectively forming a concentrated solution containing high softening point asphalt and a washing filtrate without high softening point asphalt. Compared with using traditional metal membrane tubes, it has a higher filtration accuracy, can remove low molecular weight components in the asphalt, obtain high softening point asphalt, and has a long operation cycle. Further, high purity high softening point asphalt and high purity low softening point asphalt are obtained.

[0081] In some embodiment modes, the tangential flow filtration unit 20 includes a tangential flow filter 21; as Figure 3 shown, the tangential flow filter 21 has a total asphalt solution inlet 21-E, a concentrated solution outlet 21-H, and a washing filtrate outlet 21-F; the filter element 210 of the tangential flow filter 21 is a nano membrane tube; along the tangential flow filtration direction of the asphalt solution, the nano membrane tube includes a filtration layer 211, a transition layer 212, and a support layer 213 that are sequentially stacked.

[0082] The above-mentioned nano membrane tube selected in this application reaches the nanofiltration membrane level in terms of accuracy, can intercept substances at the nanometer level (0.001 micrometers) at most, and its weight average molecular weight of intercepted organic substances is greater than 200. It uses the dynamic "cross-flow filtration" method for filtration, that is, under the pressure drive increased by a circulation pump or a booster pump, the asphalt solution flows at a certain high speed on the inner membrane layer surface of the nano membrane tube. Some asphalt components with lower molecular weights pass through the membrane pores along the direction perpendicular to the flow direction (i.e., the tangential flow direction), while most asphalt components with larger molecular weights are intercepted by the membrane, so as to achieve the purpose of washing and filtering the raw asphalt solution.

[0083] In some embodiments, the pore size of the filtration layer 211 is 0.5 to 20 nm, such as any value among 0.5, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 nm or the range value between any two of them; the pore size of the transition layer 212 is 30 to 80 nm, such as any value among 30, 35, 40, 45, 50, 55, 60, 65, 70, 75, 80 nm or the range value between any two of them; the pore size of the support layer 213 is 0.08 to 0.5 μm, such as any value among 0.08, 0.1, 0.15, 0.2, 0.25, 0.3, 0.35, 0.40, 0.45, 0.50 μm or the range value between any two of them; for another example, the pore size of the filtration layer 211 is 2 to 10 nm; the pore size of the transition layer 212 is 30 to 60 nm; the pore size of the support layer 213 is 0.1 to 0.5 μm. The overall structure of the tangential flow filter used in this application is the prior art. The innovation of this application lies in the design of the specific sizes of the pore sizes of the filtration layer, the transition layer, and the support layer and the synergistic combination among the three pore sizes. This application adopts the tangential flow filtration method, and further limits the pore sizes of each membrane layer of the filter element according to the molecular weight of asphalt. After the three-layer membranes match and cooperate, the above-mentioned high softening point asphalt can be accurately intercepted from asphalt; by setting the pore size of each layer within the above range, the macromolecular asphalt and small molecular asphalt in the asphalt solution can be better separated, preventing large particle impurities from passing through the membrane surface, ensuring the filtration accuracy. The design of this structure can ensure that after small particle impurities pass through the membrane surface, they can quickly pass through the membrane layer.

[0084] In some embodiments, the first lipophilic coating is attached to both opposite surfaces of the filtration layer 211; the second lipophilic coating is attached to both opposite surfaces of the transition layer 212; the third lipophilic coating is attached to both opposite surfaces of the support layer 213. By coating lipophilic coatings on both the inner and outer sides of the three-layer tube wall of the nanofilm tube (that is, the lipophilic coatings are applied on both sides of each layer of the membrane), and by coating a high-temperature and wear-resistant lipophilic coating on the inner side of the filtration layer of the nanofilm tube, this coating will gradually penetrate into the transition layer and finally reach the outer side of the support layer; therefore, the lipophilicity of the mixed material in each layer of the nanofilm tube is improved, which is beneficial to the flow of substances with various particle sizes in the mixed material in the nanofilm tube, and it is not easy to form blockages in the micropores of the nanofilm tube, resulting in good filtration effect and the operation cycle generally exceeding 30 days.

[0085] In some embodiments, the tangential flow filter 21 includes a housing and a filter element, and the filter element is located inside the housing; along the flow direction of the asphalt solution, the filter element has a first end at the asphalt solution inlet and a second end face at the concentrated liquid outlet. A first sealing ring is provided between the first end face and the housing, and a second sealing ring is provided between the second end face and the housing. By providing high-temperature and corrosion-resistant sealing rings at both ends of the nanofilm tube, leakage of the asphalt solution due to the high-temperature and high-pressure filtration environment can be avoided.

[0086] In some embodiments, the weight average molecular weight of the high softening point asphalt is 450 to 1000. By designing the pore sizes of the various layers of the above-mentioned nanofilm tube, high softening point asphalt with the above-mentioned molecular weight can be intercepted.

[0087] In some embodiments, the number of tangential flow filters 21 ≥ 2; multiple tangential flow filters 21 are connected in series in such a way that the concentrated liquid outlet of the previous tangential flow filter 21 is communicated with the asphalt solution inlet of the next tangential flow filter 21. For example, as Figure 2 shown, the tangential flow filter 21 includes a tangential flow filter A 21A and a tangential flow filter B 21B; the concentrated liquid outlet of the tangential flow filter A 21A is communicated with the asphalt solution inlet of the tangential flow filter B 21B. By designing multiple tangential flow filters and connecting them in series in a head-to-tail connection manner, the filtration and separation effect can be enhanced, which is beneficial to obtaining high-purity asphalt.

[0088] In some embodiments, a booster pump 214 is further provided between the tangential flow filter A 21A and the tangential flow filter B 21B; the concentrated liquid outlet of the tangential flow filter A 21A is communicated with the inlet of the booster pump 214, and the outlet of the booster pump 214 is communicated with the asphalt solution inlet of the tangential flow filter B 21B. By providing the booster pump, the feed pressure of the concentrated liquid of the tangential flow filter A 21A entering the tangential flow filter B 21B can be increased, which is beneficial to the smooth progress of tangential flow filtration and improves the filtration efficiency.

[0089] In some embodiments, the nanofilm tube of the tangential flow filter A21A includes a first filtration layer 211A, a first transition layer 212A, and a first support layer 213A that are sequentially stacked; further, the pore size of the first filtration layer 211A is 2 to 5 nm, the pore size of the first transition layer 212A is 30 to 40 nm, and the pore size of the first support layer 213A is 0.1 to 0.3 μm; the nanofilm tube of the tangential flow filter B21B includes a second filtration layer 211B, a second transition layer 212B, and a second support layer 213B that are sequentially stacked; for example, the pore size of the second filtration layer 211B is 6 to 10 nm, the pore size of the second transition layer 212B is 50 to 60 nm, and the pore size of the third support layer 213B is 0.35 to 0.5 μm. By specifically designing the pore sizes of each layer of the membranes of the front and rear two-stage tangential flow filter cartridges respectively, and having good matching and continuity of the pore sizes of each layer of the two filters in the filtration sequence, it is beneficial to the filtration effect of the asphalt solution, and thus high-purity high softening point asphalt and high-purity low softening point asphalt can be obtained.

[0090] In some embodiments, the tangential flow filtration unit 20 further includes a concentrate pump 23 and a wash filtrate pump 25; the concentrate outlet of the tangential flow filter 21 is communicated with the inlet of the concentrate pump 23, the outlet of the concentrate pump 23 is the total concentrate outlet, and this outlet is communicated with the total concentrate inlet; the wash filtrate outlet of the tangential flow filter 21 is communicated with the inlet of the wash filtrate pump 25, and the outlet of the wash filtrate pump 25 is the total wash filtrate outlet, and this outlet is communicated with the total wash filtrate inlet. By arranging liquid pumps at the outlets of the tangential flow filter respectively, the feeding pressures of the concentrate and the wash filtrate entering the next process are increased respectively, the conveying efficiency and the material quantity are improved, which is beneficial to accelerating the subsequent distillation process.

[0091] In some embodiments, the tangential flow filtration unit 20 further includes a concentrate storage tank 22 and a wash filtrate storage tank 24; the concentrate outlet of the tangential flow filter 21 is communicated with the inlet of the concentrate storage tank 22, and the outlet of the concentrate storage tank 22 is communicated with the inlet of the concentrate pump 23; the wash filtrate outlet of the tangential flow filter 21 is communicated with the inlet of the wash filtrate storage tank 24, and the outlet of the wash filtrate storage tank 24 is communicated with the inlet of the wash filtrate pump 25. For example, when there are two tangential flow filters A and B, two wash filtrate tanks are correspondingly arranged; for example, the wash filtrate storage tank 24 includes a wash filtrate storage tank A24A and a wash filtrate storage tank B24B; the wash filtrate outlet of the tangential flow filter A21A is communicated with the inlet of the wash filtrate storage tank A24A; the wash filtrate outlet of the tangential flow filter B21B is communicated with the inlet of the wash filtrate storage tank B24B; the outlets of the wash filtrate storage tank A24A and the wash filtrate storage tank B24B are respectively communicated with the wash filtrate pump 25. By arranging the concentrated acid liquid storage tank and the wash filtrate storage tank, a buffering effect is achieved, and the liquid flow pressure and the distillation tower liquid level can be stabilized.

[0092] In some embodiments, the liquid preparation unit 10 includes a solvent oil storage tank 11, an asphalt storage tank 12, a solution preparation tank 13, and a feed pump 14; the solution preparation tank 13 includes a first inlet and a second inlet; the solvent oil storage tank 11 has a solvent oil inlet for feeding solvent oil from the outside, and the outlet of the solvent oil storage tank 11 is communicated with the first inlet of the solution preparation tank 13; the asphalt storage tank 12 has an asphalt inlet for feeding asphalt from the outside, and the outlet of the asphalt storage tank 12 is communicated with the second inlet of the solution preparation tank 13; the outlet of the solution preparation tank 13 is communicated with the inlet of the feed pump 14, and the outlet of the feed pump 14 is the asphalt solution outlet, and this outlet is communicated with the total asphalt solution inlet. By providing a liquid preparation tank, it is used to mix asphalt and solvent oil according to the designed amount, so as to provide an asphalt solution with stable quality for the filtration unit.

[0093] In some embodiments, the solution preparation tank 13 includes a solution preparation tank A 13A and a solution preparation tank B 13B; the outlet of the solvent oil storage tank 11 is respectively communicated with the first inlet of the solution preparation tank A 13A and the first inlet of the solution preparation tank B 13B; the outlet of the asphalt storage tank 12 is respectively communicated with the second inlet of the solution preparation tank A 13A and the second inlet of the solution preparation tank B 13B; the outlets of the solution preparation tank A 13A and the solution preparation tank B 13B are respectively communicated with the inlet of the feed pump 14. By providing two liquid preparation tanks, the routes of tanks A and B can be switched, and a continuous filtration process can be formed to improve the filtration efficiency.

[0094] In some embodiments, the concentrated liquid outlet of the tangential flow filter 21 is communicated with the first inlet of the solution preparation tank 13. When there are two solution preparation tanks 13, the concentrated liquid outlet of the tangential flow filter 21 is respectively communicated with the first inlet of the solution preparation tank A 13A and the first inlet of the solution preparation tank B 13B. When the tangential flow filter 21 includes a tangential flow filter A 21A and a tangential flow filter B 21B; the concentrated liquid outlets of the tangential flow filter A 21A and the tangential flow filter B 21B are respectively communicated with the first inlet of the solution preparation tank A 13A; or, the concentrated liquid outlets of the tangential flow filter A 21A and the tangential flow filter B 21B are respectively communicated with the first inlet of the solution preparation tank B 13B. By providing a concentrated liquid return route, which is used to supplement solvent oil to the solution preparation tank, the viscosity of the asphalt solution can be ensured not to increase, and the washing and filtration efficiency can be ensured.

[0095] In some embodiments, the liquid preparation unit 10 further includes a flushing pump 15; the tangential flow filtration unit 20 also has a solvent flushing inlet; the inlet of the flushing pump 15 is communicated with the outlet of the solvent oil storage tank 11, and the outlet of the flushing pump 15 is communicated with the solvent flushing inlet. By providing a flushing pump, an on-line backwashing process can be carried out on the tangential flow filter to restore the filtration performance of the nano-membrane tube. This on-line cleaning can effectively remove the blockage of the membrane pores caused by ash and micro-particles, etc.

[0096] In some embodiments, the concentrated liquid treatment unit 30 includes a first distillation column 31 and a high softening point asphalt forming machine 32; the first distillation column 31 has a total concentrated liquid inlet, a first bottom outlet of the distillation column and a first solvent oil outlet; the first bottom outlet of the distillation column is communicated with the inlet of the high softening point asphalt forming machine 32, and the high softening point asphalt outlet of the high softening point asphalt forming machine 32 is used to send out the high softening point asphalt; the high softening point asphalt forming machine 32 is used to cool and form the high softening point asphalt. By arranging the distillation column, high-purity high softening point asphalt and solvent oil can be obtained.

[0097] In some embodiments, the washing filtrate treatment unit 40 includes a second distillation column 41 and a low softening point asphalt forming machine 42; the second distillation column 41 has a total washing filtrate inlet, a second bottom outlet of the distillation column and a second solvent oil outlet; the second bottom outlet of the distillation column is communicated with the inlet of the low softening point asphalt forming machine 42, and the low softening point asphalt outlet of the low softening point asphalt forming machine 42 is used to send out the low softening point asphalt; the low softening point asphalt forming machine 42 is used to cool and form high-purity asphalt of different grades (i.e., relatively low softening point asphalt). By arranging the distillation column, high-purity asphalt of different grades and solvent oil can be obtained.

[0098] In some embodiments, the preparation device further includes a cooling unit 50 and a solvent oil buffer unit 60; the first solvent oil outlet and the second solvent oil outlet are respectively communicated with the inlet of the cooling unit 50; the outlet of the cooling unit 50 is communicated with the inlet of the solvent oil buffer unit 60; the solvent oil storage tank 11 also has a solvent oil return inlet; the outlet of the solvent oil buffer unit 60 is communicated with the solvent oil return inlet. By arranging the cooling and buffer units, the solvent oil separated from the asphalt solution can be recovered and then recycled.

[0099] According to the second aspect of the present application, there is provided a method for preparing the above-mentioned high softening point asphalt, including the following steps:

[0100] Step S1: Mix the solvent oil and the asphalt to obtain an asphalt solution;

[0101] Step S2: Filter and separate the asphalt solution by a tangential flow filtration method to respectively obtain a concentrated liquid containing high softening point asphalt and a washing filtrate after cross-flow separation; wherein, the weight average molecular weight of the high softening point asphalt is ≥450;

[0102] Step S3: Perform a first distillation on the concentrated liquid containing high softening point asphalt to respectively obtain high softening point asphalt and a first solvent oil;

[0103] Step S4: Perform a second distillation on the washing filtrate after cross-flow separation to respectively obtain low softening point asphalt and a second solvent oil; wherein, the weight average molecular weight of the low softening point asphalt is <450, and this preparation method is carried out in the above-mentioned preparation device.

[0104] The high softening point asphalt preparation method provided by this application is a physical separation method. This method has simple technological steps and low energy consumption. At the same time, there is no need for heating polymerization or oxidation reactions in this method, avoiding problems such as mesophase and coking in the product caused by uneven heating. Moreover, no by-products, waste gas, or waste water are generated during the production process of this method, achieving zero emissions and having no pollution to the environment. It is an environmentally friendly production method.

[0105] In some embodiments, in step S1, the solvent oil is selected from at least one of tetrahydrofuran, toluene, pyridine, N-methylpyrrolidone, middle oil in coal liquefaction, and wash oil of coal tar; the asphalt is selected from at least one of coal liquefaction asphalt, coal tar modified asphalt, and petroleum modified asphalt, and its ash content is <0.2%; further, the weight ratio of the solvent oil to the asphalt is (1-3):1; the mixing temperature of the solvent oil and the asphalt is 80-130°C; the viscosity of the asphalt solution is 100-300 cP. By adopting the above ratio and temperature for mixing to form an asphalt solution with an appropriate viscosity, it is beneficial for subsequent filtration and separation. If the viscosity of the asphalt solution is too high, the flow rate of the asphalt solution will be slow, easily causing membrane blockage / increase in transmembrane pressure difference, and shortening the operation cycle of the filter.

[0106] In some embodiments, in step S2, the asphalt solution is pre-filtered (pretreated) before tangential flow filtration; the pretreatment can optionally adopt conventional solid-liquid separation methods in the art. For example, it can be preliminary filtration with a micron-level membrane layer separation, and the pore size of this membrane layer only needs to be slightly larger than that of the support layer.

[0107] In some embodiments, in step S2, the feed pressure of the asphalt solution in tangential flow filtration is 0.42-0.7 MPa; the tangential flow filtration is carried out under the condition that the temperature is 110-170°C. By limiting the feed pressure and filtration temperature, the filtration efficiency and filtration effect can be improved.

[0108] In some embodiments, the transmembrane pressure difference of each membrane layer of the nanofilm tube used in tangential flow filtration is ≤ 0.38 MPa. As the operation cycle of the filter extends, each molecular weight component in the asphalt solution gradually distributes between the membrane layers (i.e., the filtration layer, the transition layer, and the support layer) of the nanofilm tube and within the micropores of each membrane layer. At this time, a pressure difference (i.e., the transmembrane pressure difference) will form at the inlet and outlet of each membrane layer. The above nanofilm tube of the present application does not need to be disassembled and cleaned, and the transmembrane pressure difference of each membrane layer of the nanofilm tube can be controlled below 0.38 MPa by adjusting the discharge ratio of the concentrate outlet and the wash filtrate outlet, which can meet the wash filtration requirements for the asphalt solution; when the transmembrane pressure difference exceeds 0.38 MPa, the filtration effect of the filter cannot be guaranteed, and the nanofilm tube needs to be cleaned; the nanofilm tube can be cleaned online by backwashing to restore the filtration performance of the nanofilm tube. This online cleaning can effectively remove the blockage of membrane pores caused by ash and microparticles, etc.; at the same time, the produced high softening point asphalt has characteristics such as isotropic and good uniformity.

[0109] In some embodiments, to ensure sufficient flushing volume of the nanofilm tube, the flow rate of cross-flow flushing on the surface of the nanofilm tube can be ensured by adjusting the frequency of the feed pump, so that the mixed material near the filtration layer of the nanofilm tube flows rapidly, and at the same time, the mixed material located near the filtration layer is stirred, thereby strengthening the flushing effect of the nanofilm tube and achieving the purpose of real-time cleaning of the nanofilm tube. The large-flow filtration flushing volume makes the mixed material in the nanofilm tube flow rapidly, causing the transmembrane pressure difference of the nanofilm tube to gradually increase, which further improves the separation effect of the mixed material entering the nanofilm tube.

[0110] In some embodiments, in step S3, before the concentrate containing high softening point asphalt undergoes the first distillation, it is returned to step S1, and at the same time, a first new solvent oil is added to the asphalt solution, and the flow rate of the first new solvent oil is the same as the flow rate of the wash filtrate. By setting the concentrate circulation route and supplementing the solvent oil, the viscosity of the asphalt solution can be ensured not to increase, and the wash filtration efficiency can be guaranteed.

[0111] In some embodiments, in step S2, the tangential flow filtration is multi-stage tangential flow filtration. Specifically, the tangential flow filtration includes primary tangential flow filtration and secondary tangential flow filtration; the asphalt solution undergoes primary tangential flow filtration to obtain a primary concentrate and a primary wash filtrate respectively; the primary concentrate undergoes secondary tangential flow filtration to obtain a secondary concentrate and a secondary wash filtrate respectively; the secondary concentrate undergoes the first distillation to obtain high softening point asphalt and a first solvent oil respectively; the primary wash filtrate or the secondary wash filtrate undergoes the second distillation to obtain low softening point asphalt and a second solvent respectively. By setting two-stage series tangential filtration steps, the filtration effect of the asphalt solution can be further improved, high-purity asphalt can be obtained, and the filtration time can be shortened.

[0112] In some embodiments, in step S3, before the secondary concentrate is subjected to the first distillation, it is returned to step S1, and at the same time, a second fresh solvent oil is added to the asphalt solution; the sum of the flow rates of the primary wash filtrate and the secondary wash filtrate is the same as the flow rate of the second fresh solvent oil. By the above operations, the viscosity of the asphalt solution is ensured not to increase, and the washing and filtering efficiency is ensured; after the wash filtrate is discharged from the filter, it enters the wash filtrate storage tank and then is sent to the corresponding distillation column for distillation to obtain high-purity asphalt.

[0113] In some embodiments, the components of the concentrate with a molecular cut-off less than the molecular cut-off are completely washed and filtered out, that is, when the asphalt content in the concentrate is basically unchanged in the two cycles before and after, the concentrate is discharged from the filter and enters the concentrate storage tank, and then is sent to the corresponding distillation column for distillation to obtain high softening point asphalt. When the added solvent oil is 3 to 5 times the initial mass, the concentrate is discharged from the filter and enters the concentrate storage tank, and then is sent to the corresponding distillation column for distillation to obtain high softening point asphalt. In the method provided by the present application, the tangential flow filtration method is used for filtration, and at the same time, the continuous washing and filtering method is adopted in the operation. The volume of the asphalt solution remains unchanged. As the small-component asphalt components are removed, the viscosity of the entire asphalt solution continuously decreases, and the nano-membrane tube is less likely to be blocked, so that the operation cycle of the device becomes longer and the overall production efficiency increases.

[0114] In some embodiments, in step S3, the conditions for the first distillation include: the temperature is 220 to 350 °C, and the vacuum degree is 1 to 10 KPa. Further, the weight average molecular weight of the high softening point asphalt is 500 to 1000; the softening point of the high softening point asphalt is 220 to 260 °C. By regulating the above distillation temperature and pressure, the high softening point asphalt and the solvent oil can be better separated from the concentrate, and the separation effect can be improved.

[0115] In some embodiments, in step S4, the conditions for the second distillation include: the temperature is 220 to 350 °C, and the vacuum degree is 1 to 10 KPa. The softening point of the low softening point asphalt is 60 to 100 °C. By regulating the above distillation temperature and pressure, the low softening point asphalt and the solvent oil can be better separated from the wash filtrate, and the separation effect can be improved.

[0116] In some embodiments, a more specific preparation method includes: S1: In a solution preparation tank, solvent oil and asphalt are fully mixed to completely dissolve the asphalt to obtain an asphalt solution; S2: The asphalt solution is transported to a first tangential flow filter by a feed pump, and after filtration, a first concentrated liquid and a first washing filtrate are obtained; S3: The first concentrated liquid returns to the solution preparation device, and at the same time, solvent oil is added to the solution preparation tank at a rate equal to the outflow rate of the washing filtrate; the asphalt solution in the solution preparation tank continues to circulate along the route set in S2 - S3; the first washing filtrate enters the washing filtrate storage tank, and then through a washing filtrate pump, it is sent to the corresponding distillation device for distillation to obtain high-purity asphalt, and the recovered solvent oil enters the device for reuse; S4: When the components in the asphalt solution with a molecular cut-off lower than the set value are completely washed and filtered out, the first concentrated liquid enters the concentrated liquid storage tank, and then through a concentrated liquid pump, it is sent to the corresponding distillation device for distillation to obtain high softening point asphalt, and the recovered solvent oil enters the device for reuse; at the same time, the solution in another solution preparation tank enters the tangential flow filter for filtration. By using the above method, a continuous production effect is achieved, and the output efficiency can be improved.

[0117] In some embodiments, in the above more specific preparation method, two-stage tangential flow filtration is adopted: In step S3, after the first concentrated liquid is pressurized by a booster pump, it enters the second tangential flow filter, the second concentrated liquid returns to the solution preparation tank, and at the same time, solvent oil is added to the solution preparation tank at a rate equal to the sum of the outflow rates of the second washing filtrates; the asphalt solution in the solution preparation tank continues to circulate along the route set in S2 - S3; when the components in the asphalt solution with a molecular cut-off lower than the set value are completely washed and filtered out, the circulation ends, and the concentrated liquid enters the concentrated liquid storage tank; the first washing filtrate enters the first washing filtrate storage tank; the second washing filtrate enters the second washing filtrate storage tank; in step S4, the first and second washing filtrates are sent to the corresponding distillation devices for distillation by a washing filtrate pump to obtain two kinds of high-purity asphalt of different grades, and the recovered solvent oil enters the device for reuse; the first concentrated liquid is sent from the concentrated liquid storage tank, and then through a concentrated liquid pump, it is sent to the corresponding distillation device for distillation to obtain high softening point asphalt, and the recovered solvent oil enters the device for reuse; at the same time, the solution in another solution preparation tank enters the tangential flow filter for filtration. By using the two-stage filtration method, two grades of high-purity asphalt and one kind of high softening point asphalt can be obtained simultaneously. Compared with only using a first tangential flow filter, the time taken for one process is reduced by 1 / 3.

[0118] The following further describes the present application in detail with specific embodiments, and these embodiments should not be construed as limiting the scope claimed by the present application.

[0119] In the following embodiments, one of the raw bitumens used is the coal liquefaction bitumen produced in the coal liquefaction oil residue extraction process of Ordos Coal Liquefaction Branch of Shenhua Coal to Liquid Chemicals Company. The softening point of this bitumen is 162°C, and the softening point deviation is ±3°C, denoted as No. 1 bitumen; the other raw bitumen is a petroleum-based modified bitumen, sourced from Zhejiang Kaboen New Materials Co., Ltd. The softening point of this bitumen is 150°C, and the softening point deviation is ±5°C, denoted as No. 2 bitumen.

[0120] In the tangential flow filter's nanofilm tube used in the following embodiments, the tube length is 1200 mm and the diameter is 32 mm. The nanofilm tube has three layers of tube walls with different pore sizes, which are, from the inside to the outside, the filtration layer, the transition layer, and the support layer; among them,

[0121] No. 1 membrane tube: The pore size of the filtration layer is 2 nm, the pore size of the transition layer is 30 nm, and the pore size of the support layer is 0.1 μm;

[0122] No. 2 membrane tube: The pore size of the filtration layer is 4 nm, the pore size of the transition layer is 35 nm, and the pore size of the support layer is 0.2 μm;

[0123] No. 3 membrane tube: The pore size of the filtration layer is 5 nm, the pore size of the transition layer is 40 nm, and the pore size of the support layer is 0.3 μm;

[0124] No. 4 membrane tube: The pore size of the filtration layer is 8 nm, the pore size of the transition layer is 60 nm, and the pore size of the support layer is 0.5 μm.

[0125] In the embodiments of this application, the softening point and coking value of the bitumen are detected by the methods of GB / T 2294 and GB / T 8727.

[0126] Example 1

[0127] A preparation device for high softening point bitumen, as Figure 1 shown, includes:

[0128] The liquid preparation unit 10 includes a solvent oil storage tank 11, an asphalt storage tank 12, solution preparation tanks A 13A and B 13B, a feed pump 14, and a flushing pump 15; the liquid preparation unit 10 is used to mix a solvent oil raw material and an asphalt raw material to obtain an asphalt solution; the solvent oil storage tank 11 has a solvent oil inlet for feeding external solvent oil, and the solvent oil storage tank 11 also has a solvent oil return inlet; the outlet of the solvent oil storage tank 11 is respectively communicated with the first inlet of the solution preparation tank A 13A and the first inlet of the solution preparation tank B 13B; the asphalt storage tank 12 has an asphalt inlet for feeding external asphalt, and the outlet of the asphalt storage tank 12 is respectively communicated with the second inlet of the solution preparation tank A 13A and the second inlet of the solution preparation tank B 13B; the outlets of the solution preparation tank A 13A and the solution preparation tank B 13B are respectively communicated with the inlet of the feed pump 14; the inlet of the flushing pump 15 is communicated with the outlet of the solvent oil storage tank 11;

[0129] The tangential flow filtration unit 20 includes a single-stage tangential flow filter 21, a concentrate storage tank 22, a concentrate pump 23, a wash filtrate storage tank 24, and a wash filtrate pump 25; as Figure 3 shown, the tangential flow filter 21 has an asphalt solution total inlet 21-E, a solvent flushing inlet, a concentrate outlet 21-H, and a wash filtrate outlet 21-F; the outlet of the flushing pump 15 is communicated with the solvent flushing inlet; the asphalt solution outlet of the feed pump 14 is communicated with the asphalt solution total inlet; the concentrate outlet of the tangential flow filter 21 is communicated with the inlet of the concentrate storage tank 22, and the outlet of the concentrate storage tank 22 is communicated with the inlet of the concentrate pump 23; the concentrate outlet of the tangential flow filter 21 is also respectively communicated with the first inlet of the solution preparation tank A 13A and the first inlet of the solution preparation tank B 13B; the wash filtrate outlet of the tangential flow filter 21 is communicated with the inlet of the wash filtrate storage tank 24, and the outlet of the wash filtrate storage tank 24 is communicated with the inlet of the wash filtrate pump 25; the tangential flow filtration unit 20 is used to intercept and separate high softening point asphalt with a weight average molecular weight ≥ 450 from the asphalt solution to respectively obtain a concentrate containing high softening point asphalt and a wash filtrate after interception and separation; wherein, the tangential flow filter 21 has a filter element 210, which is the above-mentioned No. 1 nano-membrane tube, and sealing rings are respectively arranged between the opposite ends of the membrane tube and the housing along the flowing direction of the asphalt solution; as Figure 3 shown, along the tangential flow filtration direction of the asphalt solution (i.e., from the inside of the filter element to the outside of the filter element or the wash filtrate permeation direction), the nano-membrane tube includes a filtration layer 211, a transition layer 212, and a support layer 213 which are sequentially stacked; the pore size of the filtration layer 211 is 2 nm; the pore size of the transition layer 212 is 30 nm; the pore size of the support layer 213 is 0.1 μm; first lipophilic coatings are attached to both opposite surfaces of the filtration layer 211; second lipophilic coatings are attached to both opposite surfaces of the transition layer 212; third lipophilic coatings are attached to both opposite surfaces of the support layer 213;

[0130] The concentrated liquid treatment unit 30 includes a first distillation tower 31 and a high softening point asphalt forming machine 32; the concentrated liquid treatment unit 30 is used to separately separate high softening point asphalt and a first solvent oil from the concentrated liquid; the first distillation tower 31 has a total concentrated liquid inlet, a bottom outlet of the first distillation tower, and a first solvent oil outlet; the total concentrated liquid inlet is communicated with the total outlet of the concentrated liquid pump 23; the first solvent oil outlet is communicated with the inlet of the cooling unit 50; the bottom outlet of the first distillation tower is communicated with the inlet of the high softening point asphalt forming machine 32, and the high softening point asphalt outlet of the high softening point asphalt forming machine 32 is used to send out the high softening point asphalt;

[0131] The washing filtrate treatment unit 40 includes a second distillation tower 41 and a low softening point asphalt forming machine 42; the washing filtrate treatment unit 40 is used to separately separate low softening point asphalt and a second solvent oil from the washing filtrate; the second distillation tower 41 has a total washing filtrate inlet, a bottom outlet of the second distillation tower, and a second solvent oil outlet; the total washing filtrate inlet is communicated with the total outlet of the washing filtrate pump 25; the second solvent oil outlet is communicated with the inlet of the cooling unit 50; the bottom outlet of the second distillation tower is communicated with the inlet of the low softening point asphalt forming machine 42, and the low softening point asphalt outlet of the low softening point asphalt forming machine 42 is used to send out the low softening point asphalt; the outlet of the cooling unit 50 is communicated with the inlet of the solvent oil buffer unit 60; the outlet of the solvent oil buffer unit 60 is communicated with the solvent oil return inlet of the solvent oil storage tank 11.

[0132] The method for separating high softening point asphalt from the asphalt solution by using this device includes the following steps:

[0133] Step S1: In two solution preparation tanks, stir the solvent oil and No. 1 asphalt at a mass ratio of 3:1 at 110 °C for 1 h to fully mix them, so that the asphalt is completely dissolved to obtain an asphalt solution with a viscosity of 150 cP;

[0134] Step S2: After the asphalt solution in solution preparation tank A is preliminarily filtered and pretreated by a feed filter (Y-type filter, 1 μm), it is transported to the tangential flow filter by a feed pump and circulated for 0.5 h first; at the same time, the temperature at the tangential flow filter is raised to 130 °C;

[0135] Step S3: Open the valve of the washing filtrate discharge port, adjust the transmembrane pressure of the ceramic membrane to 0.35 MPa, start washing and filtering, and separate to obtain a concentrated liquid containing high softening point asphalt and a washing filtrate after cross-flow separation;

[0136] Step S4: The concentrated liquid continues to return to solution preparation tank A, and at the same time, add solvent oil to solution preparation tank A at a rate the same as the outflow rate of the washing filtrate to keep the solution volume unchanged;

[0137] Step S5: The washing filtrate enters the washing filtrate storage tank and is pumped to the second distillation column for distillation at a distillation temperature of 310 °C and a vacuum degree of 4 kPa; the recovered second solvent oil is sent to the solvent oil storage tank for reuse; while the produced high-purity asphalt is sent to the corresponding molding machine for cooling and molding; the softening point of the high-purity asphalt is 68.4 °C;

[0138] Step S6: When the components in the asphalt solution with a molecular cut-off less than the molecular cut-off are basically washed and filtered out (the newly added solvent oil is 4 times the initial mass), all the concentrated liquid enters the concentrated liquid storage tank and is then pumped to the first distillation column for distillation at a distillation temperature of 305 °C and a vacuum degree of 4 kPa; the recovered first solvent oil is sent to the solvent oil storage tank for reuse; the obtained high softening point asphalt is sent to the corresponding molding machine for cooling and molding; the softening point of the product high softening point asphalt is 227.7 °C, and the coking value is 80.2%;

[0139] Step S7: The solution preparation tank A repeats Step S1 to prepare the asphalt solution for standby; the solution in another solution preparation tank B is cut into the filtration system, and Steps S2 to S7 are repeated to prepare high softening point asphalt to realize continuous operation of the device.

[0140] Example 2

[0141] The difference between Example 2 and Example 1 is that the filter element 210 of the tangential flow filter 21 is a No. 2 nano membrane tube; the pore size of the filter layer 211 is 4 nm; the pore size of the transition layer 212 is 35 nm; the pore size of the support layer 213 is 0.2 μm;

[0142] The softening point of the obtained high-purity asphalt is 75.7 °C, the softening point of the product high softening point asphalt is 238.6 °C, and the coking value is 81.2%.

[0143] Example 3

[0144] The difference between Example 3 and Example 1 is that the filter element 210 of the tangential flow filter 21 is a No. 3 nano membrane tube; the pore size of the filter layer 211 is 5 nm; the pore size of the transition layer 212 is 40 nm; the pore size of the support layer 213 is 0.5 μm;

[0145] The softening point of the high-purity asphalt is 82.0 °C, the softening point of the product high softening point asphalt is 244.5 °C, and the coking value is 82.1%.

[0146] Example 4

[0147] The difference between Example 4 and Example 1 is that the filter element 210 of the tangential flow filter 21 is a No. 4 nano membrane tube; the pore size of the filter layer 211 is 8 nm; the pore size of the transition layer 212 is 60 nm; the pore size of the support layer 213 is 0.5 μm;

[0148] The softening point of the obtained high-purity asphalt is 90.6 °C, the softening point of the product high softening point asphalt is 251.2 °C, and the coking value is 82.7%.

[0149] Example 5

[0150] The difference between Example 5 and Example 1 is that the filter element 210 of the tangential flow filter 21 is a No. 5 nanofilm tube; the pore size of the filter layer 211 is 0.5 nm; the pore size of the transition layer 212 is 30 nm; the pore size of the support layer 213 is 0.08 μm;

[0151] The softening point of the obtained high-purity asphalt is 56.7 °C, the softening point of the product high softening point asphalt is 210.8 °C, and the coking value is 77.2%.

[0152] Example 6

[0153] The difference between Example 6 and Example 1 is that the filter element 210 of the tangential flow filter 21 is a No. 6 nanofilm tube; the pore size of the filter layer 211 is 20 nm; the pore size of the transition layer 212 is 80 nm; the pore size of the support layer 213 is 0.5 μm;

[0154] The softening point of the obtained high-purity asphalt is 105.6 °C, the softening point of the product high softening point asphalt is 257.4 °C, and the coking value is 83.0%.

[0155] Example 7

[0156] The difference between Example 7 and Example 1 is that, as Figure 2 shown, the tangential flow filter 21 is a two-stage filter;

[0157] Comprising: The tangential flow filtration unit 20 includes two-stage tangential flow filters A21A, tangential flow filters B21B, a booster pump 214, a concentrate storage tank 22, a concentrate pump 23, a wash filtrate storage tank 24A, a wash filtrate storage tank 24B, and a wash filtrate pump 25; The concentrate outlet of the tangential flow filter A21A is communicated with the inlet of the booster pump 214, and the outlet of the booster pump 214 is communicated with the asphalt solution inlet of the tangential flow filter B21B; The concentrate outlet of the tangential flow filter B21B is communicated with the inlet of the concentrate storage tank 22; The concentrate outlet of the tangential flow filter B21B is also respectively communicated with the first inlet of the solution preparation tank A13A and the first inlet of the solution preparation tank B13B; The outlet of the concentrate storage tank 22 is communicated with the inlet of the concentrate pump 23; The total concentrate outlet of the concentrate pump 23 is communicated with the total concentrate inlet of the first distillation tower 31; The wash filtrate outlet of the tangential flow filter A21A is communicated with the inlet of the filtrate storage tank A24A; The wash filtrate outlet of the tangential flow filter B21B is communicated with the inlet of the filtrate storage tank B24B; The outlets of the wash filtrate storage tank A24A and the wash filtrate storage tank B24B are respectively communicated with the inlet of the wash filtrate pump 25; The total wash filtrate outlet of the wash filtrate pump 25 is communicated with the total wash filtrate inlet of the second distillation tower 41; Among them, as Figure 3 shown, the nano-membrane tube (No. 1 membrane tube) of the tangential flow filter A21A includes a first filtration layer 211A, a first transition layer 212A, and a first support layer 213A that are sequentially stacked; The pore size of the first filtration layer 211A is 2 nm, the pore size of the first transition layer 212A is 30 nm, and the pore size of the first support layer 213A is 0.1 μm; The nano-membrane tube (No. 4 membrane tube) of the tangential flow filter B21B includes a second filtration layer 211B, a second transition layer 212B, and a second support layer 213B that are sequentially stacked; The pore size of the second filtration layer 211B is 8 nm, the pore size of the second transition layer 212B is 60 nm, and the pore size of the third support layer 213B is 0.5 μm.

[0158] The method for separating high softening point asphalt from the asphalt solution using this device includes the following steps:

[0159] Step S2: After the asphalt solution passes through the series-connected primary tangential flow filter A and secondary tangential flow filter B in sequence, circulate for 0.5 h; At the same time, raise the temperature at the two-stage tangential flow filter to 130 °C;

[0160] Step S3: Open the valves at the two-stage wash filtrate discharge outlets, and adjust the transmembrane pressure of the two-stage tangential flow filters to 0.35 MPa respectively to start washing and filtering;

[0161] Step S1, Steps S4 - S7 are the same as in Example 1.

[0162] The softening points of the obtained first-grade and second-grade high-purity asphalt are 65.3 °C and 92.1 °C respectively, the softening point of the product high softening point asphalt is 254.4 °C, and the coking value is 83.3%.

[0163] Example 8

[0164] The difference between Example 8 and Example 7 is that the first-stage tangential flow filter A uses a No. 2 nano membrane tube;

[0165] The softening points of the obtained first-grade and second-grade high-purity asphalt are 70.8 °C and 94.7 °C respectively, the softening point of the product high softening point asphalt is 254.7 °C, and the coking value is 82.3%.

[0166] Example 9

[0167] The difference between Example 9 and Example 7 is that the first-stage tangential flow filter A uses a No. 3 nano membrane tube;

[0168] The softening points of the obtained first-grade and second-grade high-purity asphalt are 76.8 °C and 96.2 °C respectively, the softening point of the product high softening point asphalt is 255.9 °C, and the coking value is 83.4%.

[0169] Example 10

[0170] The difference between Example 10 and Example 7 is that the temperature at both stages of the tangential flow filter is 140 °C;

[0171] The softening points of the obtained first-grade and second-grade high-purity asphalt are 68.5 °C and 93.7 °C respectively, the softening point of the product high softening point asphalt is 256.9 °C, and the coking value is 83.7%.

[0172] Example 11

[0173] The difference between Example 11 and Example 8 is that the raw material asphalt selects No. 2 petroleum-based modified asphalt;

[0174] The softening points of the obtained first-grade and second-grade high-purity asphalt are 62.5 °C and 87.6 °C respectively, the softening point of the product high softening point asphalt is 250.1 °C, and the coking value is 79.8%.

[0175] From the operation results of the above Examples 1 to 11, it can be seen that the method for preparing high softening point asphalt provided by this application is a physical separation method. This method has simple process steps and low energy consumption, and can successfully separate high softening point asphalt and high-purity asphalt from asphalt; further using a two-stage tangential flow filter can obtain two-stage high-purity asphalt and a kind of high softening point asphalt at the same time. Compared with only using a one-stage tangential flow filter, the time used in one process is reduced by 1 / 3.

[0176] The filter in the preparation system of the high softening point asphalt provided by this application uses a nano-membrane tube as the filter element, which has three layers of tube walls with gradually increasing pore sizes. It can prevent large particle impurities from passing through the membrane surface, ensuring the filtration accuracy. The design of this structure can ensure that after small particle impurities pass through the membrane surface, they can quickly pass through the membrane layer. Compared with the use of traditional metal membrane tubes, the filtration accuracy is higher, and it can remove low molecular weight components in the asphalt to obtain high softening point asphalt. This provides a preparation method for high softening point modified asphalt that can operate for a long period. In addition, the three layers of tube walls of this nano-membrane tube have all undergone special treatment with an organic coating, making it have better lipophilicity. Therefore, blockage substances are not easily formed in the micropores of the nano-membrane tube, the filtration effect is good, and the operation cycle generally exceeds 30 days.

[0177] The preparation system of the high softening point asphalt provided by this application includes solution preparation, a filter, and product post-treatment parts, with simple technological steps and low energy consumption. At the same time, in this method, there is no need for reactions such as heating polymerization or oxidation, avoiding problems such as mesophase and coking in the product caused by uneven heating. Moreover, in the method provided by the present invention, there are no by-products, waste gas, or waste water generated during the production process, achieving zero emissions and having no pollution to the environment. It is an environmentally friendly production method.

[0178] In the method provided by this application, tangential flow filtration is used for filtration, and at the same time, a continuous washing and filtration method is adopted during the operation. The volume of the asphalt solution remains unchanged. As small component asphalt is removed, the viscosity of the entire asphalt solution continuously decreases, and the nano-membrane tube is less likely to be blocked, making the operation cycle of the device longer and the overall production efficiency increased.

[0179] In the method provided by this application, by adjusting the discharge ratio of the concentrate discharge port and the purified liquid discharge port, the transmembrane pressure difference of the ceramic membrane is controlled below 0.38 MPa, which can meet the requirements for washing and filtering the asphalt solution. At the same time, the produced high softening point asphalt has characteristics such as isotropic and good uniformity.

[0180] It should be noted that the terms "first", "second", etc. in the description and claims of this application are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. It should be understood that such terms can be interchanged under appropriate circumstances so that the embodiments of this application described here can be implemented in an order other than those described here.

[0181] The above are only the preferred embodiments of this application and are not used to limit this application. For those skilled in the art, this application can have various changes and modifications. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of this application shall be included within the protection scope of this application.

Claims

1. A preparation device for high softening point asphalt, characterized in that, The device includes: A liquid preparation unit (10) having an asphalt inlet, a solvent oil inlet, and an asphalt solution outlet; the liquid preparation unit (10) is used for mixing a solvent oil raw material and an asphalt raw material to form an asphalt solution; A tangential flow filtration unit (20) having an asphalt solution total inlet, a concentrate total outlet, and a wash filtrate total outlet; the asphalt solution total inlet is communicated with the asphalt solution outlet; the tangential flow filtration unit (20) is used for intercepting and separating high softening point asphalt with a weight average molecular weight ≥ 450 from the asphalt solution to respectively obtain a concentrate containing high softening point asphalt and a wash filtrate after intercepting and separating; A concentrate treatment unit (30) having a concentrate total inlet, a high softening point asphalt outlet, and a first solvent oil outlet; the concentrate total outlet is communicated with the concentrate total inlet; the concentrate treatment unit (30) is used for respectively separating the high softening point asphalt and the first solvent oil from the concentrate; A wash filtrate treatment unit (40) having a wash filtrate total inlet, a low softening point asphalt outlet, and a second solvent oil outlet; the wash filtrate total outlet is communicated with the wash filtrate total inlet; the wash filtrate treatment unit (40) is used for respectively separating low softening point asphalt with a weight average molecular weight < 450 and a second solvent oil from the wash filtrate.

2. The preparation device of the high softening point asphalt according to claim 1, wherein, The tangential flow filtration unit (20) includes a tangential flow filter (21), the tangential flow filter (21) has the asphalt solution total inlet, a concentrate outlet, and a wash filtrate outlet; the tangential flow filter (21) has a filter element (210), and the filter element (210) is a nano membrane tube; along the tangential flow filtration direction of the asphalt solution, the nano membrane tube includes a filtration layer (211), a transition layer (212), and a support layer (213) which are sequentially stacked.

3. The preparation device of the high softening point asphalt according to claim 2, characterized in that, The pore size of the filtration layer (211) is 0.5 - 20 nm; the pore size of the transition layer (212) is 30 - 80 nm; the pore size of the support layer (213) is 0.08 - 0.5 μm; preferably, the pore size of the filtration layer (211) is 2 - 10 nm; the pore size of the transition layer (212) is 30 - 60 nm; the pore size of the support layer (213) is 0.1 - 0.5 μm; And / or, the weight average molecular weight of the high softening point asphalt is 450 - 1000.

4. The preparation apparatus for high softening point asphalt according to claim 2 or 3, characterized in that, The number of the tangential flow filters (21) ≥ 2; a plurality of the tangential flow filters (21) are connected in series in such a way that the concentrate outlet of the previous tangential flow filter (21) is communicated with the asphalt solution inlet of the next tangential flow filter (21); Preferably, the tangential flow filter (21) includes a tangential flow filter A (21A) and a tangential flow filter B (21B); the concentrate outlet of the tangential flow filter A (21A) is communicated with the asphalt solution inlet of the tangential flow filter B (21B); Preferably, a booster pump (214) is further provided between the tangential flow filter A (21A) and the tangential flow filter B (21B); the concentrate outlet of the tangential flow filter A (21A) is communicated with the inlet of the booster pump (214), and the outlet of the booster pump (214) is communicated with the asphalt solution inlet of the tangential flow filter B (21B); Preferably, the nanofilm tube of the tangential flow filter A (21A) includes a first filter layer (211A), a first transition layer (212A), and a first support layer (213A) which are sequentially stacked; Preferably, the pore size of the first filter layer (211A) is 2 to 5 nm, the pore size of the first transition layer (212A) is 30 to 40 nm, and the pore size of the first support layer (213A) is 0.1 to 0.3 μm; Preferably, the nanofilm tube of the tangential flow filter B (21B) includes a second filter layer (211B), a second transition layer (212B), and a second support layer (213B) which are sequentially stacked; Preferably, the pore size of the second filter layer (211B) is 6 to 10 nm, the pore size of the second transition layer (212B) is 50 to 60 nm, and the pore size of the third support layer (213B) is 0.35 to 0.5 μm.

5. The preparation device of high softening point asphalt according to any one of claims 2 to 4, characterized in that The tangential flow filtration unit (20) further includes a concentrate pump (23) and a wash filtrate pump (25); the concentrate outlet of the tangential flow filter (21) is communicated with the inlet of the concentrate pump (23), the outlet of the concentrate pump (23) is the total concentrate outlet, and the total concentrate outlet is communicated with the total concentrate inlet; the wash filtrate outlet of the tangential flow filter (21) is communicated with the inlet of the wash filtrate pump (25), the outlet of the wash filtrate pump (25) is the total wash filtrate outlet, and the total wash filtrate outlet is communicated with the total wash filtrate inlet; Preferably, the tangential flow filtration unit (20) further includes a concentrate storage tank (22) and a wash filtrate storage tank (24); the concentrate outlet of the tangential flow filter (21) is communicated with the inlet of the concentrate storage tank (22), and the outlet of the concentrate storage tank (22) is communicated with the inlet of the concentrate pump (23); the wash filtrate outlet of the tangential flow filter (21) is communicated with the inlet of the wash filtrate storage tank (24), and the outlet of the wash filtrate storage tank (24) is communicated with the inlet of the wash filtrate pump (25).

6. The preparation device of high softening point asphalt according to claim 5, characterized in that, The wash filtrate storage tank (24) includes a wash filtrate storage tank A (24A) and a wash filtrate storage tank B (24B); the wash filtrate outlet of the tangential flow filter A (21A) is communicated with the inlet of the wash filtrate storage tank A (24A); the wash filtrate outlet of the tangential flow filter B (21B) is communicated with the inlet of the wash filtrate storage tank B (24B); the outlets of the wash filtrate storage tank A (24A) and the wash filtrate storage tank B (24B) are respectively communicated with the wash filtrate pump (25).

7. The preparation device for high softening point asphalt according to any one of claims 2 to 6, characterized in that, The liquid preparation unit (10) includes a solution preparation tank (13) and a feed pump (14); the solution preparation tank (13) includes a first inlet and a second inlet; the outlet of the solution preparation tank (13) is communicated with the inlet of the feed pump (14), the outlet of the feed pump (14) is the asphalt solution outlet, and the asphalt solution outlet is communicated with the total asphalt solution inlet; Preferably, the liquid preparation unit (10) further includes a solvent oil storage tank (11) and an asphalt storage tank (12); the solvent oil storage tank (11) has the solvent oil inlet for feeding external solvent oil, and the outlet of the solvent oil storage tank (11) is communicated with the first inlet of the solution preparation tank (13); the asphalt storage tank (12) has the asphalt inlet for feeding external asphalt, and the outlet of the asphalt storage tank (12) is communicated with the second inlet of the solution preparation tank (13); Preferably, the concentrate outlet of the tangential flow filter (21) is communicated with the first inlet of the solution preparation tank (13); Preferably, the solution preparation tank (13) includes a solution preparation tank A (13A) and a solution preparation tank B (13B); the outlet of the solvent oil storage tank (11) is respectively communicated with the first inlet of the solution preparation tank A (13A) and the first inlet of the solution preparation tank B (13B); the outlet of the asphalt storage tank (12) is respectively communicated with the second inlet of the solution preparation tank A (13A) and the second inlet of the solution preparation tank B (13B); the outlets of the solution preparation tank A (13A) and the solution preparation tank B (13B) are respectively communicated with the inlet of the feed pump (14); Preferably, the concentrate outlet of the tangential flow filter (21) is respectively communicated with the first inlet of the solution preparation tank A (13A) and the first inlet of the solution preparation tank B (13B); Preferably, the tangential flow filter (21) includes a tangential flow filter A (21A) and a tangential flow filter B (21B); the concentrate outlet of the tangential flow filter A (21A) and the concentrate outlet of the tangential flow filter B (21B) are respectively communicated with the first inlet of the solution preparation tank A (13A); or, the concentrate outlet of the tangential flow filter A (21A) and the concentrate outlet of the tangential flow filter B (21B) are respectively communicated with the first inlet of the solution preparation tank B (13B); Preferably, the liquid preparation unit (10) further includes a flushing pump (15); the tangential flow filtration unit (20) further has a solvent flushing inlet; the inlet of the flushing pump (15) is communicated with the outlet of the solvent oil storage tank (11), and the outlet of the flushing pump (15) is communicated with the solvent flushing inlet.

8. The preparation device of high softening point asphalt according to claim 7, characterized in that, The concentrated liquid treatment unit (30) includes a first distillation column (31) and a high softening point asphalt forming machine (32); the first distillation column (31) has the total concentrated liquid inlet, the first bottom outlet of the distillation column, and the first solvent oil outlet; the first bottom outlet of the distillation column is communicated with the inlet of the high softening point asphalt forming machine (32), and the high softening point asphalt outlet of the high softening point asphalt forming machine (32) is used to send out the high softening point asphalt; And / or, the washing filtrate treatment unit (40) includes a second distillation column (41) and a low softening point asphalt forming machine (42); the second distillation column (41) has the total washing filtrate inlet, the second bottom outlet of the distillation column, and the second solvent oil outlet; the second bottom outlet of the distillation column is communicated with the inlet of the low softening point asphalt forming machine (42), and the low softening point asphalt outlet of the low softening point asphalt forming machine (42) is used to send out the low softening point asphalt; And / or, the preparation device further includes a cooling unit (50) and a solvent oil buffer unit (60); the first solvent oil outlet and the second solvent oil outlet are respectively communicated with the inlet of the cooling unit (50); the outlet of the cooling unit (50) is communicated with the inlet of the solvent oil buffer unit (60); the solvent oil storage tank (11) also has a solvent oil return inlet; the outlet of the solvent oil buffer unit (60) is communicated with the solvent oil return inlet.

9. A preparation method of high softening point asphalt, characterized in that, Comprising the following steps: Step S1: Mix the solvent oil and asphalt to obtain an asphalt solution; Step S2: Filter and separate the asphalt solution by a tangential flow filtration method to respectively obtain a concentrated liquid containing high softening point asphalt and a washing filtrate after cross-flow separation; wherein, the weight average molecular weight of the high softening point asphalt is ≥450; Step S3: Perform a first distillation on the concentrated liquid containing high softening point asphalt to respectively obtain the high softening point asphalt and the first solvent oil; Step S4: Perform a second distillation on the washing filtrate after cross-flow separation to respectively obtain low softening point asphalt and the second solvent oil; wherein, the weight average molecular weight of the low softening point asphalt is <450; Wherein, the preparation method is carried out in the preparation device according to any one of claims 1 to 8.

10. The preparation method of the high softening point asphalt according to claim 9, wherein, In the step S1, the solvent oil is selected from at least one of tetrahydrofuran, toluene, pyridine, N-methylpyrrolidone, medium oil in coal liquefaction, and wash oil of coal tar; And / or, the asphalt is selected from at least one of coal liquefaction asphalt, coal tar modified asphalt, and petroleum modified asphalt; And / or, the weight ratio of the solvent oil to the asphalt is (1 to 3):1; And / or, the mixing temperature of the solvent oil and the asphalt is 80 to 130 °C; And / or, the viscosity of the asphalt solution is 100 to 300 cP; And / or, in the step S2, the asphalt solution is pre-filtered before the tangential flow filtration; And / or, the feed pressure of the asphalt solution in the tangential flow filtration is 0.42 to 0.7 MPa; And / or, the tangential flow filtration is carried out under the condition that the temperature is 110 to 170 °C; And / or, the transmembrane pressure difference of each membrane layer of the nanofilm tube used in the tangential flow filtration ≤ 0.38 MPa; And / or, the tangential flow filtration is multi-stage tangential flow filtration; And / or, in the step S3, the conditions of the first distillation include: the temperature is 220 - 350 °C, and the vacuum degree is 1 - 10 KPa; And / or, the weight average molecular weight of the high softening point asphalt is 500 - 1000; And / or, the softening point of the high softening point asphalt is 220 - 260 °C; And / or, in the step S4, the conditions of the second distillation include: the temperature is 220 - 350 °C, and the vacuum degree is 1 - 10 KPa; And / or, the softening point of the low softening point asphalt is 60 - 100 °C; And / or, in the step S1, before the concentrated solution containing the high softening point asphalt undergoes the first distillation, it is returned to the step S1, and at the same time, a first new solvent oil is added to the asphalt solution, and the flow rate of the first new solvent oil is the same as the flow rate of the washing filtrate; And / or, in the step S2, the tangential flow filtration includes primary tangential flow filtration and secondary tangential flow filtration; the asphalt solution undergoes the primary tangential flow filtration to obtain a primary concentrated solution and a primary washing filtrate respectively; the primary concentrated solution undergoes the secondary tangential flow filtration to obtain a secondary concentrated solution and a secondary washing filtrate respectively; the secondary concentrated solution undergoes the first distillation to obtain the high softening point asphalt and the first solvent oil respectively; the primary washing filtrate or the secondary washing filtrate undergoes the second distillation to obtain the low softening point asphalt and the second solvent respectively; Preferably, in the step S3, before the secondary concentrated solution undergoes the first distillation, it is returned to the step S1, and at the same time, a second new solvent oil is added to the asphalt solution; the sum of the flow rates of the primary washing filtrate and the secondary washing filtrate is the same as the flow rate of the second new solvent oil.

Images