A process for improving light phase bitumen yield

Abstract

The present application relates to the separation process optimization field of light phase pitch, and discloses a process method for improving the yield of light phase pitch, comprising: fully mixing coal-based soft pitch raw materials and mixed solvents in a pipeline according to a preset ratio to form a uniform mixed solution; performing temperature raising treatment on the mixed solution, so that the mixed solution reaches a preset temperature interval; making the heated mixed solution enter a settling tank, and standing in the settling tank according to an optimal load to reach a preset optimal standing time; continuously taking out light phase pitch from a liquid outlet of a light phase solution tank at the upper part of the settling tank, continuously taking out heavy phase pitch from the bottom of the settling tank through a heavy phase pump during the taking-out process, continuously supplementing anthracene oil into the settling tank from the lower part of the heavy phase pitch solution settling tank during the taking-out process of the light phase pitch and the heavy phase pitch, and conveying the heavy phase pitch after being mixed with the anthracene oil to a rear-end process for solvent recovery and reprocessing.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of separation process optimization of light phase pitch, and particularly relates to a process method for improving light phase pitch yield. BACKGROUND

[0002] Light phase pitch refers to a low-density, low-impurity-content pitch component separated from raw materials through mixed solvent extraction and sedimentation separation technology in the process of treating coal-based soft pitch. Its core features are as follows: light phase pitch is in liquid or semi-solid state, has low density, and is usually in the upper layer of the settling tank; compared with heavy phase pitch, light phase pitch has lower viscosity and better flowability, and the main component is the soluble component (such as aromatic hydrocarbons, colloid, etc.) in pitch. Light phase pitch is a high-value-added product in deep processing of coal tar, and can be used to produce high-quality carbon materials including needle coke and carbon fiber, waterproof materials, etc. The impurities affecting the purity of light phase pitch are mainly quinoline insolubles (QI) and toluene insolubles (TI), and the purity directly affects the conductivity, mechanical strength and other properties of subsequent products.

[0003] The current extraction of light phase pitch has the following problems:

[0004] 1. The combined process of solvent extraction and centrifugal separation is mainly used, which is complicated and requires large equipment. Solvent extraction mainly extracts effective components through mixed solvents, and then performs sedimentation in large equipment. After sedimentation is completed, separation is directly performed to realize light phase pitch extraction;

[0005] 2. The yield of light phase pitch is low. The yield of light phase pitch is generally 80%-85% under the current process production;

[0006] 3. Due to the combined process of solvent extraction and centrifugal separation, the quality control of light phase pitch is difficult, and the stability of the finished product is relatively poor;

[0007] 4. The solvent used in the current process flow is difficult to recycle and reuse. SUMMARY

[0008] The summary section is intended to introduce the subject matter briefly what will be described in detail in the detailed description section. The summary section does not purport to be a critical or exhaustive recitation of the key features or necessary features of the claimed subject matter, nor does it define the scope of the claimed subject matter.

[0009] The present application provides a process method for improving light phase pitch yield to solve one or more of the technical problems mentioned in the background section.

[0010] The present application provides a process method for improving light phase pitch yield, characterized in that it comprises the following steps:

[0011] Step one: mix the coal-based soft pitch raw material and the mixed solvent in a pipeline according to a preset ratio to form a uniform mixed solution, the mixed solvent is a mixed solvent of de-phenol oil and aviation kerosene, and the aromatic-aliphatic ratio of the mixed solvent is 0.96-1.85:1;

[0012] Step two: perform temperature raising treatment on the mixed solution to make the mixed solution reach a preset temperature range;

[0013] Step three: make the temperature-raised mixed solution enter a settling tank, and stand in the settling tank according to an optimal load to reach a preset optimal standing time;

[0014] Step four: continuously take out the light phase pitch from the light phase solution tank of the upper part of the settling tank, continuously take out the heavy phase pitch containing QI residues from the bottom of the settling tank through a heavy phase pump in the process of taking out the light phase pitch, and continuously supplement anthracene oil to the settling tank from the lower part of the settling tank in the process of taking out the light phase pitch and the heavy phase pitch;

[0015] Step five: after the heavy phase pitch is back-blended with the anthracene oil, the mixture is transported to a rear-end process for solvent recovery and reprocessing.

[0016] Optionally, the mixed solvent is a mixed solvent of de-phenol oil and aviation kerosene.

[0017] Optionally, the de-phenol oil is a mixture of one or more than one of aromatic hydrocarbons, trimethylbenzene, tetramethylbenzene, indene, naphthalene, and methylnaphthalene.

[0018] Optionally, the aviation kerosene includes alkanes, aromatic hydrocarbons, and olefins of different fractions, wherein the mass content of the aromatic hydrocarbons is below 20%, and the mass content of the olefins is below 3%.

[0019] Optionally, the preset ratio of the coal-based soft pitch raw material to the mixed solvent is 0.7:1.

[0020] Optionally, the aromatic-aliphatic ratio of the de-phenol oil to the aviation kerosene in the mixed solvent is 0.96-1.26:1.

[0021] Optionally, the aromatic-aliphatic ratio of the de-phenol oil to the aviation kerosene in the mixed solvent is 1±0.04:1.

[0022] Optionally, the preset temperature range is 125-135℃.

[0023] Optionally, the optimal load is 8 t / h.

[0024] Optionally, the preset optimal standing time is 5.5-5.9 hours.

[0025] Optionally, the heavy phase pitch is transported to the back-end process after being back-blended with anthracene oil for solvent recovery and reprocessing, and the process further comprises: separating the recovered anthracene oil and heavy phase pitch to return the solvent to a solvent recycling tank, recovering the anthracene oil using a distillation system, and uniformly mixing the remaining residual liquid with coal tar at a proper ratio as other industrial raw materials.

[0026] Optionally, the optimal aromatic-aliphatic ratio is mainly determined by the yield of light phase pitch and the proportion of QI impurities under different working conditions in the experiment.

[0027] The present application has the following beneficial effects: 1. By adjusting the selected solvent and solvent ratio, the solvent extraction method can be used to directly extract light phase pitch, and the specific method is: continuously injecting anthracene oil to continuously extract light phase pitch, continuously extracting light phase pitch from the light phase solution tank at the upper part of the settling tank, and continuously extracting heavy phase pitch containing QI residues from the bottom of the settling tank through a heavy phase pump, and continuously supplementing anthracene oil to the settling tank at the lower part of the heavy phase pitch solution in the process of extracting light phase pitch and heavy phase pitch, so that the extraction valve is prevented from being blocked, the viscosity of the solution system is reduced by continuously supplementing anthracene oil, and the proportion of impurities in the light phase pitch is reduced, thereby improving the yield of light phase pitch, reducing QI impurities, and ensuring the continuous extraction of light phase pitch and heavy phase pitch at the lower end;

[0028] 2. By adjusting the selected solvent and solvent ratio, the continuous extraction of light phase pitch is realized, and the yield of light phase pitch is stably improved to more than 90% for a long period of time;

[0029] 3. By adjusting the selected solvent and solvent ratio, the solvent extraction method can be used to directly extract light phase pitch, and the solvent extraction method can be used to extract light phase pitch at one time, so that high-quality light phase pitch with QI impurities less than 0.1% (QI impurities less than 0.03% in the experiment) can be stably produced;

[0030] 4. The extracted heavy phase pitch raw material can be recycled and utilized, the comprehensive utilization rate of the pretreated raw material is 100%, the heavy phase pitch is transported to the back-end process after being back-blended with anthracene oil, the solvent recovery and reprocessing are performed, the recovered anthracene oil and heavy phase pitch are separated to return the solvent to a solvent recycling tank, the anthracene oil is recovered using a distillation system, the remaining residual liquid is uniformly mixed with coal tar at a proper ratio as other industrial raw materials, and the pretreated raw material can be completely utilized. BRIEF DESCRIPTION OF DRAWINGS

[0031] The above and other features, advantages, and aspects of the embodiments of the present application will become more apparent by referring to the following detailed description in conjunction with the accompanying drawings. Throughout the drawings, the same or similar reference numerals indicate the same or similar elements. It should be understood that the drawings are schematic, and the elements and elements are not necessarily drawn to scale.

[0032] Figure 1A process flow diagram of a process for increasing the yield of light phase pitch. DETAILED DESCRIPTION

[0033] The present application will be described in more detail with reference to the drawings. Although some embodiments of the present application are shown in the drawings, it is understood that the present application can be embodied in various forms and should not be interpreted as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present application will be thoroughly and completely understood. It should be understood that the drawings and embodiments of the present application are for illustrative purposes only and are not intended to limit the scope of the present application.

[0034] It should also be noted that only parts related to the present application are shown in the drawings for the purpose of description. The embodiments in the present application and the features in the embodiments can be combined with each other in the case of no conflict.

[0035] It should be noted that the terms "first", "second", and the like in the present application are only used to distinguish different devices, modules or units, and are not intended to limit the order or interdependence of the functions performed by these devices, modules or units.

[0036] It should be noted that the terms "one", "multiple" in the present application are illustrative and not restrictive, and those skilled in the art should understand that unless otherwise explicitly stated in the context, it should be understood as "one or more".

[0037] The names of the messages or information exchanged between the devices of the present application are only for illustrative purposes, and are not intended to limit the scope of the messages or information.

[0038] The present application will be described in more detail with reference to the drawings. Although some embodiments of the present application are shown in the drawings, it is understood that the present application can be embodied in various forms and should not be interpreted as being limited to the embodiments set forth herein. Rather, these embodiments are provided so that the present application will be thoroughly and completely understood. It should be understood that the drawings and embodiments of the present application are for illustrative purposes only and are not intended to limit the scope of the present application.

[0039] In one embodiment, as shown in Figure 1 A process for increasing the yield of light phase pitch, characterized in that it comprises the following steps:

[0040] S101 mixing the coal-based soft pitch raw material with the mixed solvent in the pipeline according to the preset ratio to form a uniform mixed liquid, the mixed solvent being a mixed solvent of dephenol oil and aviation kerosene, and the aromatic aliphatic ratio of the mixed solvent being 0.96-1.85:1;

[0041] In the embodiment, the coal-based soft pitch raw material is coal-based soft pitch with softening point between 35.1 and 42.3℃ and QI (quinoline insoluble) content between 1.92% and 2.86%. The QI impurity in the soft pitch has very small particle size. During movement in the oil system, the outer part of the QI body is continuously wrapped by heavier TI-QS (TI-QS is a composite coating layer composed of toluene insoluble TI and quinoline soluble QS, which hinders the settlement of QI particles) and other oil components in the soft pitch in contact with it. The QI itself has no cohesion and cannot agglomerate. However, during movement in the oil system, the QI particles may agglomerate due to the effect of the outer wrapping layer, and the particle size increases. At the same time, since the outer wrapping layer is oil, it has viscosity and is mixed with the oil system. The density difference between the QI particle body and the system cannot overcome the viscosity resistance of the outer wrapping layer and the system, so it is difficult to settle.

[0042] S102, the mixed solution is subjected to temperature rising treatment so as to reach a preset temperature range.

[0043] In the embodiment, the commonly used heating means in the field is heating by a heating furnace. The principle of the step is that the local system viscosity is greatly reduced in the moment when the soft pitch contacts the mixed solvent with the above ratio in a temperature environment of 125-135℃, which is beneficial to overcome the viscosity resistance of the coal-based soft pitch raw material and the mixed solvent system, and is beneficial to the settlement of the mixed solution.

[0044] S103, the mixed solution after temperature rising is introduced into a settling tank, and is statically placed in the settling tank according to the best load to reach a preset best static placement time.

[0045] In the embodiment, the principle of determining the best static placement time in the step is that, under a reasonable heavy phase pitch yield condition, when the minimum settlement time of the mixed solution is lower than the effective residence time provided by the inside of the settling equipment, the light phase pitch yield and quality can be guaranteed. The greater the time difference in the overlapping area, the greater the excess amount, and the greater the processing load adjustment space. When the minimum settlement time of the mixed solution is equal to (or close to) the effective residence time provided by the inside of the settling equipment, the quality of the light phase pitch is qualified, but the stability is affected to a certain extent. At this time, the effective residence time of the settling equipment corresponding to the QI quality critical point of the light phase pitch is equal to the minimum settlement time of the mixed solution. When the minimum settlement time of the mixed solution is greater than the effective residence time provided by the inside of the settling equipment, the quality of the light phase pitch cannot be qualified.

[0046] S104, the light phase pitch is continuously extracted from the light phase solution tank of the upper part of the settling tank through the discharge port. The heavy phase pitch containing QI residue is continuously extracted from the bottom of the settling tank through the heavy phase pump. During the extraction of the light phase pitch and the heavy phase pitch, anthracene oil is continuously supplemented into the settling tank at the lower part of the heavy phase pitch solution.

[0047] In the embodiment, the light phase bitumen is continuously extracted from the light phase solution tank of the upper part of the settling tank, the heavy phase bitumen containing QI residues is continuously extracted from the bottom of the settling tank by the heavy phase pump, and the anthracene oil is continuously supplemented to the settling tank at the lower part of the heavy phase bitumen solution tank during the extraction of the light phase bitumen and the heavy phase bitumen. The three steps are performed simultaneously, and the effect of continuously supplementing the anthracene oil to the settling tank at the lower part of the heavy phase bitumen solution tank is to prevent the extraction valve from being blocked, and the viscosity of the solution system is reduced by continuously supplementing the anthracene oil, thereby reducing the proportion of impurities in the light phase bitumen. The method improves the yield of light phase bitumen and reduces QI impurities while ensuring the continuous extraction of light phase bitumen and heavy phase bitumen at the lower end.

[0048] In S105, the heavy phase bitumen is transported to the rear-end process after being back-mixed with the anthracene oil, and the solvent is recovered and treated again.

[0049] In the embodiment, the removal rate of QI impurities is shown in Table 1.

[0050]

[0051] Table 1: QI data of light phase bitumen solution during the experiment of a process for improving the yield of light phase bitumen;

[0052] Beneficial effects: The method significantly improves the yield and quality of light phase bitumen in coal-based soft pitch by optimizing the mixing of mixed solvents and the continuous extraction of light phase bitumen. The yield of light phase bitumen is stably above 90% (the highest is 91.67%, see Table 2), the quinoline insoluble (QI) content is controlled below 0.1% for a long time, and the toluene insoluble (TI) content is maintained in a controllable range of 3.3%-9.5%. By adjusting the selected solvents and solvent ratio, high-quality light phase bitumen can be directly produced by solvent extraction, which significantly enhances the stability of the process and ensures the continuity of industrial production.

[0053] In one embodiment, the mixed solvent is a mixture of dephenolated oil and aviation kerosene.

[0054] In the embodiment, the main role of dephenolated oil in the method is to quickly dissolve QI particles, strip and extract QI particles and the outer coating layer that is insoluble in dephenolated oil. The aviation kerosene component functions to reduce the viscosity of the system, so that the volume of QI particles stripped of the outer coating layer is rapidly reduced. Since the density of QI particles is higher than that of other components in the system, the QI particles can rapidly settle in the mixed liquid with reduced viscosity.

[0055] In one embodiment, the preset ratio of coal-based soft pitch raw material to mixed solvent is 0.7:1.

[0056] In the embodiment, as shown in Table 2, 0.7:1 is the optimal mixing ratio of coal-based soft pitch raw material to mixed solvent determined during the experiment.

[0057]

[0058] Table 2: The important node mixing solvent ratio and main quality data during the test of a process for improving the yield of light phase asphalt;

[0059] In one embodiment, the ratio of de-phenolated oil to aviation kerosene in the mixed solvent is 0.96-1.26:1.

[0060] In this embodiment, the ratio of 0.96-1.26:1 is the sub-optimal ratio of de-phenolated oil to aviation kerosene. Within this range, the viscosity of the solution system in the settling device increases, but does not exceed the critical amount of the effective residence time of the settling device.

[0061] In one embodiment, the ratio of de-phenolated oil to aviation kerosene in the mixed solvent is 1±0.04:1.

[0062] In this embodiment, the ratio of de-phenolated oil to aviation kerosene of 1±0.04:1 is the optimal ratio determined by the test. The determination process of the optimal ratio is shown in Table 2, and the principle is that the optimal ratio of the mixed solvent suitable for the settling separation of each complex mixed component system is not a single point, but a range interval; under the conditions that the settling device, temperature environment, load, and solvent ratio remain unchanged and the original mixed solvent ratio itself is in the optimal applicable interval, with the gradual increase of the ratio of aromatic to aliphatic, the dissolution ability of de-phenolated oil to the TI-QS component wrapped on the outer surface of QI particles is simultaneously enhanced, and the reduction of kerosene content will simultaneously weaken the ability of kerosene to reduce the viscosity of the system. Under the combined action, the viscosity of the system increases synchronously, the gradual increase of the dissolution ability within the optimal applicable interval strengthens its stripping ability to the TI-QS component wrapped on the outside of QI particles, which is beneficial to the separation efficiency of QI; when the viscosity further increases, the settling time will be simultaneously extended. Because it is still within the applicable interval and does not exceed the critical amount of the effective residence time of the settling device, the quality and yield of light phase asphalt are not affected, but it is not the optimal ratio.

[0063] When the ratio of aromatic and aliphatic continues to increase until it is out of the applicable range, the actual amount of kerosene component in the mixed solvent is reduced, which makes the viscosity of the system itself insufficient to support the effective settling of QI particles; the excess dephenolized oil, while meeting the requirement of stripping the TI-QS component wrapped outside the QI particles, also exhibits excess extraction capacity, which extracts a part of the TI-QS component existing in the soft pitch system into the dephenolized oil solvent layer. The excess local concentrated dephenolized oil belongs to marginal and layered homogeneous extraction of the TI-QS component in the soft pitch system in contact with it, which forms a settling oil film in the dephenolized oil layer. The TI-QS component has a higher density than the dephenolized oil. In the process of rapid settling, the QI impurity particles in the TI-QS component re-generate an oil film, and the QI particles re-generate an oil film after the gradual dispersion of the dephenolized oil in the soft pitch system. The QI particles cannot be stripped after the re-generation of the oil film, which leads to the increase of particle size and the increase of settling resistance, and the settling time is indirectly prolonged. At the same time, whether the QI particles wrapped with the TI-QS component can settle in the new system or not is related to the thickness of the outer wrapping layer and the viscosity difference between the surface and the system. When the density difference cannot overcome the surface tension, an infinite theoretical settling time is required, which is reflected in the decrease of yield and quality, and even the system cannot settle.

[0064] In one embodiment, the heavy phase pitch is transported to the back-end process after being back-blended with anthracene oil, and the solvent is recovered and reprocessed. The recovered anthracene oil and the heavy phase pitch are separated from the solvent and returned to the solvent recycling tank. The anthracene oil is recovered using a distillation system, and the remaining residual liquid is uniformly mixed with coal tar at an appropriate ratio to be used as other industrial raw materials.

[0065] To further solve the technical problems described in the background section, i.e., the solvent used in the current process is difficult to recycle and reuse, in some embodiments of the present application, the recovered anthracene oil and the heavy phase pitch are separated from the solvent and returned to the solvent recycling tank. The anthracene oil is recovered using a distillation system, and the remaining residual liquid containing unseparated gum and a small amount of QI is uniformly mixed with coal tar at an appropriate ratio to be used as a high-quality raw material for producing modified pitch in a tar plant. The comprehensive utilization rate of the pretreated raw materials is 100%.

[0066] In one embodiment, the optimal aromatic and aliphatic ratio is mainly determined by the yield of light phase pitch and the proportion of QI impurities under different working conditions in the experiment.

[0067] Some specific embodiments of the present application are provided below:

[0068] Example 1: The input soft pitch raw material is blended with a mixed solvent having an aromatic and aliphatic ratio of 0.98-1.0 and a solvent ratio of 0.8, and the initial working condition is 8 t / h of soft pitch feedstock. The continuous output of heavy phase pitch solution is adjusted to adjust the light phase pitch solution QI, and anthracene oil is continuously added after the heavy phase pitch solution outlet valve to prevent blockage. In this embodiment, the light phase pitch QI is 0.04%, and the light phase pitch yield is 78.59%.

[0069] Example 2: Put in soft pitch raw material, test the possible highest yield of light phase pitch under the condition of solvent ratio 0.7, aromatic aliphatic ratio 1.0, soft pitch feed quantity 8 t / h as initial condition, adjust the continuous output of heavy phase pitch solution to adjust the light phase pitch solution QI, at the same time continuously supplement anthracene oil after the output valve of heavy phase pitch solution to prevent blockage, under the premise of keeping the light phase pitch solution QI stable and qualified, gradually reduce the output proportion of heavy phase pitch to improve the yield of light phase pitch, the output quantity of heavy phase pitch is gradually reduced from 22.52% of soft pitch to 7.29% of soft pitch, during which the quality inspection data of light phase pitch QI is normal, the yield of light phase pitch is gradually improved from 77.30% to 90.16% and then tends to be stable.

[0070] Example 3: Put in soft pitch raw material, under the condition of solvent ratio 0.7, soft pitch feed quantity 8 t / h as initial condition, adjust the continuous output of heavy phase pitch solution to adjust the light phase pitch solution QI, at the same time continuously supplement anthracene oil after the output valve of heavy phase pitch solution to prevent blockage, continuously improve the aromatic aliphatic ratio to 1.26, during which the appearance speed of sand-like fine particles separated from the solution under the condition of 1.0 aromatic aliphatic ratio gradually slows down with the increase of aromatic aliphatic ratio, until it disappears, and is replaced by visible thick particles, the required theoretical time of sedimentation is prolonged, during which the quality of light phase pitch solution is continuously qualified; when the aromatic aliphatic ratio is adjusted from 1.26 to 1.6, the light phase pitch solution QI starts to show a trend of unqualified state (0.03%), and the highest peak value is 0.14% on the same day; according to the structure model of sedimentation tank, the effective sedimentation time in the sedimentation tank on September 17 is 5.3 h, it is inferred that under the condition of solvent ratio 0.7 and treatment load 8 t / h, the upper limit critical value of aromatic aliphatic ratio is close to 1.26, when it exceeds this critical value, the effective residence time provided by the sedimentation tank will be lower than the actual sedimentation time required by QI separation; keep the solvent ratio at 0.7 and continue to increase the aromatic aliphatic ratio from 1.6 to 1.81, the current effective residence time is calculated as 5.3 h, the light phase pitch solution QI increases by 1.02%, and then remains at 0.7% with slight fluctuations. According to the data analysis, the amount of kerosene added is seriously insufficient under this condition, and it cannot meet the needs of reducing the viscosity of the system or assisting in stripping the wrapped layer, the viscosity increases, and it is not enough to achieve effective separation within the existing effective residence time; the aromatic aliphatic ratio is quickly adjusted from the original 2.04 to 2.58, the solvent ratio is adjusted from 0.7 to 1.0, and the light phase pitch solution QI is 0.96%, during which the light phase pitch output solution is continuously unqualified; it is calculated that the effective residence time of the mixed solution in the sedimentation tank is 4.5 h; the aromatic aliphatic ratio is adjusted from 2.52 to 2.4, the volume ratio remains 1.0; the load is adjusted to 6 t / h, during which the light phase pitch QI is unqualified.

[0071] The embodiment mainly observes the asphalt solution sample taken before the inlet of the settling tank. When the QI particles in the solution present fine oil sand-like particles, the settling speed is fast, and the instantaneous separation is complete. At this time, it is the best range of aromatic fat ratio. On this basis, the proportion of heavy phase asphalt solution is continuously reduced, and the yield of light phase asphalt can be explored higher, and the actual quality turning point can be found. When the QI particles present the state of being wrapped by external oil, the settling speed is significantly slowed down, and the particles are in a suspended state in the system, and there is no sign of instantaneous separation. The quality of the light phase asphalt solution is continuously qualified, which is the suboptimal aromatic fat ratio. When the QI of the light phase asphalt solution starts to show the trend of unqualified state, it is the usable aromatic fat ratio range. When the QI of the light phase asphalt solution is unqualified, the aromatic fat ratio is unusable.

[0072]

[0073]

[0074] Table 3: The main product yield prepared by the process method for improving the yield of light phase asphalt in embodiments 1 to 3;

[0075] Table 3 is the main product yield prepared by embodiments 1 to 3. As can be seen from the yield on the graph, the solvent ratio is 0.7, the aromatic fat ratio is 1±0.04, and the load is 8 t / h. This condition is the best applicable range of mixed solvent ratio. The solvent ratio is 0.7, the aromatic fat ratio is 1.19-1.26, and the load is 8 t / h. This condition is close to the best applicable range. At this time, the regulation of the mixed solvent aromatic fat ratio does not deviate from the applicable range.

[0076] The above description is only some of the preferred embodiments of the present application and the explanation of the applied technical principles. Those skilled in the art should understand that the scope of the application involved in the present application is not limited to the technical solutions formed by the specific combination of the above technical features. Meanwhile, it should also cover other technical solutions formed by the above technical features or their equivalent features in any combination without departing from the above inventive concept. For example, the above features are replaced with the technical features disclosed in the present application (but not limited to) having similar functions to form technical solutions.

Claims

1. A process for improving the yield of light phase asphalt, characterized in that, Includes the following steps: Step 1: Mix the coal-based soft pitch raw material and the mixed solvent in a pipeline according to a preset ratio to form a uniform mixture. The mixed solvent is a mixture of dephenolized oil and aviation kerosene. The aromatic ratio of the mixed solvent is 0.96 to 1.85:

1. The optimal aromatic ratio is determined by the yield of light phase pitch and the proportion of QI impurities under different working conditions in the experiment. Step 2: Heat the mixture to bring it to a preset temperature range; Step 3: The heated mixture is introduced into the settling tank and allowed to stand for the preset optimal settling time at the optimal load. The principle for determining the optimal settling time is that, under a reasonable heavy phase asphalt yield, when the minimum settling time of the mixture is lower than the effective residence time that the settling equipment can provide, the yield and quality of the light phase asphalt can be guaranteed. The greater the time difference between the two overlapping areas, the greater the margin and the greater the room for adjustment of the processing load. Step 4: Continuously extract light phase asphalt from the drain outlet of the light phase solution tank at the top of the settling tank. During the extraction process, continuously extract heavy phase asphalt containing QI residue from the bottom of the settling tank using a heavy phase pump. During the extraction of both light and heavy phase asphalt, anthracene oil is continuously added to the settling tank at the bottom of the heavy phase asphalt solution. These three steps are performed simultaneously. The purpose of continuously adding anthracene oil to the settling tank at the bottom of the heavy phase asphalt solution is to prevent the extraction valve from clogging and to reduce the viscosity of the solution system by continuously adding anthracene oil, thereby reducing the proportion of impurities in the light phase asphalt. This ensures the continuous extraction of both light phase asphalt and the lower heavy phase asphalt while increasing the yield of light phase asphalt and reducing QI impurities. Step 5: After the heavy phase pitch and anthracene oil are re-blended, they are transported to the downstream process for solvent recovery and reprocessing.

2. The process method for improving the yield of light phase asphalt according to claim 1, characterized in that, The dephenolized oil is a mixture of one or more of the following: trimethylbenzene, tetramethylbenzene, indene, naphthalene, and methylnaphthalene.

3. The process method for improving the yield of light phase asphalt according to claim 1, characterized in that, The aviation kerosene includes alkanes, aromatics, and olefins of different fractions, wherein the mass content of aromatics is less than 20% and the mass content of olefins is less than 3%.

4. The process method for improving the yield of light phase asphalt according to claim 1, characterized in that, The preset ratio of coal-based soft pitch raw material to mixed solvent is 0.7:

1.

5. The process method for improving the yield of light phase asphalt according to claim 1, characterized in that, The ratio of phenol-free oil to aviation kerosene in the mixed solvent is 0.96–1.26:

1.

6. A process method for improving the yield of light phase asphalt according to any one of claims 1, characterized in that, The ratio of phenol-free oil to aviation kerosene in the mixed solvent is 1 ± 0.04:

1.

7. The process method for improving the yield of light phase asphalt according to claim 1, characterized in that, The preset temperature range is 125℃~135℃.

8. The process method for improving the yield of light phase asphalt according to claim 1, characterized in that, The optimal load is 8t / h.

9. The process method for improving the yield of light phase asphalt according to claim 1, characterized in that, The preset optimal settling time is 5.5 to 5.9 hours.

10. A process method for improving the yield of light phase asphalt according to any one of claims 1-9, characterized in that, After the heavy phase pitch and anthracene oil are recombined, they are transported to the downstream process for solvent recovery and reprocessing. This process also includes separating the solvent from the recovered anthracene oil and heavy phase pitch and returning it to the solvent recycling tank. The anthracene oil is then recovered using a distillation system. The remaining residue is mixed with coal tar in an appropriate ratio to form other industrial raw materials.

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