Method and device for adsorbing and removing polycyclic aromatic hydrocarbon by using mesoporous material

Abstract

The invention relates to the technical field of adsorption refining of petroleum fractions, in particular to a method and a device for adsorbing and removing polycyclic aromatic hydrocarbons by using mesoporous materials, and the method and the device for adsorbing and removing the polycyclic aromatic hydrocarbons by using the mesoporous materials have the advantages that the diluted raw oil is adsorbed under normal temperature and normal pressure conditions by using the mesoporous materials with different average pore diameters; after the refined oil leaves the adsorption tower to be recycled and collected, the adsorption tower is switched to a waiting area to be subjected to desorption operation, and under the action of a desorption agent and reverse blowing gas, a component rich in polycyclic aromatic hydrocarbon is obtained; the device comprises a raw material oil tank, a dilution solvent tank, a mixing tank, a first adsorption tower, a second adsorption tower, a third adsorption tower, a first recovery solvent tank and a second recovery solvent tank. The device is simple, the operation method is simple and easy to implement, the removal rate of the polycyclic aromatic hydrocarbon in the obtained refined oil is high, continuous raw oil feeding and polycyclic aromatic hydrocarbon removal work can be achieved, the dilution solvent is recycled, the production cost is reduced, and industrial production is easier.

Description

Technical Field

[0001] The invention relates to the technical field of adsorption refining of petroleum fractions, and is a method and device for removing condensed aromatic hydrocarbons by adsorption of mesoporous materials. Background Art

[0002] In addition to the main hydrocarbon components, petroleum products also contain trace amounts of sulfides, oxygenates, nitrogenates and chlorides. The presence of these impurities will not only corrode metal pipes and equipment, causing environmental pollution, but will also lead to catalyst poisoning in some catalytic processes, seriously affecting the performance and life of the catalyst. The room temperature catalytic adsorption refining technology using solid adsorbents has been industrially applied in many domestic devices such as butene isomerization, propane / isobutane dehydrogenation, C4 solid acid alkylation, C4 catalytic cracking and MTBE for raw material pretreatment.

[0003] The solid adsorbent material used in adsorption refining technology is based on the principle of separation by utilizing the difference in adsorption capacity of each component in the mixture on the solid surface of the adsorbent. The performance of the adsorbent has an important influence on the adsorption separation effect. The specific surface area, pore size distribution, surface functional groups, etc. of the adsorbent are the main factors affecting the performance of the adsorbent. Therefore, the selection of the adsorbent is very important and determines the adsorption rate and the effect of adsorption refining to remove impurities.

[0004] Commonly used adsorbents include activated carbon, silica gel, activated alumina, polymer resin, molecular sieves, etc. Among them, molecular sieve adsorbents have the advantages of large specific surface area, high selectivity, high mechanical strength, stable chemical properties, etc., and are widely used.

[0005] A Chinese patent document with publication number CN113307761A discloses an adsorption separation-desorption method for removing carbazole from anthracene oil using a solid adsorbent quaternary ammonium salt as a material. The adsorption selectivity for carbazoles can exceed 60%, while the adsorption selectivity for other aromatic hydrocarbons in anthracene oil does not exceed 30%.

[0006] A Chinese patent document with publication number CN202111514646A discloses a method for preparing low-aromatic transformer oil by medium-pressure hydrogenation using cycloalkyl distillate oil as raw material, the method comprising: 1) the cycloalkyl distillate oil enters a first hydrogenation reactor, passes through a hydrogenation refining reaction zone and a deep dearomatization reaction zone, and realizes hydrogenation removal of sulfur and nitrogen compounds in the oil product and hydrogenation saturation of aromatic hydrocarbons; 2) the reaction stream enters a second reactor, passes through a selective ring-opening reaction zone, an isomerization decondensation reaction zone and a supplementary refining reaction zone, respectively, to realize selective ring opening of polycyclic compounds, isomerization of paraffins (branched chains) and saturation of cracked olefins; 3) the reaction product is subjected to gas-liquid separation and distillation separation to obtain a low-aromatic transformer oil fraction and a clean light oil fraction.

[0007] A Chinese patent document with publication number CN202211321818A discloses a method for removing rubber antioxidants from transformer oil, which relates to the field of transformer oil. 801 adsorbent is added to transformer oil, mixed and stirred, and used to adsorb rubber antioxidants in transformer oil, and the removal rate of the antioxidant can reach 100%.

[0008] From the adsorption refining technology in the above-mentioned existing patent documents, the hydrocarbon oil products used for adsorption refining to remove aromatics are mostly lubricating oil components with low viscosity such as transformer oil, but the application of medium and heavy vacuum distillate oil, lubricating oil and other components is relatively small. The traditional white clay silica gel adsorption method requires a large amount of dilution solvent (the mass ratio of dilution solvent to raw material is as high as 10 to 20:1) and backwashing dilution solvent, which cannot be applied to industrial production and practice. Therefore, it is necessary to study a new method for adsorption removal of polycyclic aromatic hydrocarbons. Summary of the invention

[0009] The present invention provides a method and device for removing polycyclic aromatic hydrocarbons by adsorption of mesoporous materials, which overcomes the deficiencies of the above-mentioned prior art and can effectively solve the problems of large consumption of dilution solvent and desorbent and high production cost in the existing adsorption refining technology of heavy distillate oil.

[0010] One of the technical solutions of the present invention is achieved through the following measures: a method for removing polycyclic aromatic hydrocarbons by adsorption by a mesoporous material, comprising the following steps: a first step, mixing a required amount of raw material oil with a diluent solvent to obtain a mixed raw material; a second step, the mixed raw material enters a first adsorption tower from top to bottom, and the polycyclic aromatic hydrocarbons in the mixed raw material are adsorbed and treated by a first mesoporous material in the first adsorption tower to obtain a first refined oil mixed liquid, and after the first mesoporous material is saturated with adsorbed polycyclic aromatic hydrocarbons, the first adsorption tower enters a waiting area; a third step, the first refined oil mixed liquid flows out from the lower part of the first adsorption tower and is subjected to a desolventizing treatment to obtain refined oil and the removed diluent solvent, wherein the diluent solvent is returned to the diluent solvent tank. The refined oil is recycled and collected in the tank; in the fourth step, after the refined oil is recovered and collected, the first adsorption tower in the waiting area is cut off from the original adsorption system and enters the desorption system, and the first adsorption tower performs desorption and back-blowing operations to obtain components rich in polycyclic aromatic hydrocarbons; in the fifth step, when the first adsorption tower performs desorption and back-blowing operations, the mixed raw material enters the second adsorption tower from top to bottom, and the polycyclic aromatic hydrocarbons in the mixed raw material are adsorbed by the second mesoporous material in the second adsorption tower to obtain a second refined oil mixed liquid, and after the second mesoporous material is saturated with polycyclic aromatic hydrocarbons, the second adsorption tower enters the waiting area; in the sixth step, the second refined oil mixed liquid flows out from the lower part of the second adsorption tower and is desolventized to obtain The refined oil and the removed dilution solvent, wherein the dilution solvent is returned to the dilution solvent tank for recycling, and the refined oil is recovered and collected; the seventh step, after the recovery and collection of the refined oil is completed, the second adsorption tower in the waiting area is cut out from the original adsorption system and enters the desorption system, and the second adsorption tower performs desorption and backwashing operations to obtain components rich in polycyclic aromatic hydrocarbons; the eighth step, when the first adsorption tower and the second adsorption tower are performing desorption and backwashing operations, the mixed raw material enters the third adsorption tower from top to bottom, and the polycyclic aromatic hydrocarbons in the mixed raw material are adsorbed by the third mesoporous material in the third adsorption tower to obtain a third refined oil mixed liquid, and after the third mesoporous material is saturated with the polycyclic aromatic hydrocarbons, the third adsorption tower enters the waiting area, and the same At this time, the first adsorption tower completes the desorption and backblowing operations, and the first adsorption tower after desorption and backblowing is cut out of the desorption system and enters the waiting area; in the ninth step, the third refined oil mixed liquid flows out from the lower part of the third adsorption tower and is subjected to desolventizing treatment to obtain refined oil and removed dilution solvent, wherein the dilution solvent is returned to the dilution solvent tank for recycling, and the refined oil is recovered and collected; in the tenth step, after the refined oil recovery and collection is completed, the third adsorption tower in the waiting area is cut out from the original adsorption system and enters the desorption system, the third adsorption tower is subjected to desorption and backblowing operations to obtain a component rich in polycyclic aromatic hydrocarbons, and at the same time, the first adsorption tower in the waiting area is cut into the adsorption system, and the above-mentioned second to ninth steps are repeated.

[0011] The following is a further optimization and / or improvement of one of the above-mentioned technical solutions: In the first step, the mass ratio of the feedstock oil to the dilution solvent is 1:0.8 to 1:1.05, wherein the feedstock oil is a heavy distillate oil and the dilution solvent is a non-polar hydrocarbon solvent.

[0012] In the above second step, fifth step and eighth step, the adsorption treatment time is 40 min to 120 min.

[0013] The above-mentioned heavy distillate oil is heavy oil minus two-fraction oil or four-fraction oil, and the diluting solvent is petroleum ether or naphtha components at 90°C to 120°C (i.e., No. 120 diluting solvent oil or No. 180 diluting solvent oil).

[0014] The average pore volume of the first mesoporous material, the second mesoporous material and the third mesoporous material are all 0.5 ml / g to 1.0 ml / g, and the specific surface area is all 200 m 2 / g to 500m 2 / g, the adsorbents in the first mesoporous material, the second mesoporous material and the third mesoporous material are all hydrogenation catalyst protective agents, and the metal active components loaded by the hydrogenation catalyst protective agents are all double components composed of VIB group and VⅢ group metals.

[0015] In the above-mentioned dual components composed of VIB group and VIII group metals, the VIB group metal is 5% to 10% by mass percentage in terms of oxide, and the VIII group metal is 1% to 5% by mass percentage in terms of oxide.

[0016] The specific processes of the desorption and backflushing operations of the first adsorption tower, the second adsorption tower and the third adsorption tower are as follows: first, a desorbent is sequentially introduced into the first adsorption tower, the second adsorption tower and the third adsorption tower from bottom to top for desorption and desorption; then, industrial nitrogen with a volume concentration of 99.9% is used for backflushing from bottom to top to obtain components rich in polycyclic aromatic hydrocarbons.

[0017] The desorption temperature is 90°C to 160°C, the desorption time is 50min to 1h, the back-purge time is 1.5 to 2h, and the industrial nitrogen temperature is 90°C to 150°C.

[0018] The second technical solution of the present invention is achieved by the following measures: a device for implementing the method of removing condensed aromatic hydrocarbons by adsorption of mesoporous materials, comprising a raw oil tank, a dilution solvent tank, a mixing tank, a first adsorption tower, a second adsorption tower, a third adsorption tower, a first recovery solvent tank and a second recovery solvent tank, a raw oil input pipeline is fixedly connected between the lower outlet of the raw oil tank and the upper inlet of the mixing tank, a dilution solvent input pipeline is fixedly connected between the lower outlet of the dilution solvent tank and the lower inlet of the mixing tank, a first mixed material inlet pipeline is fixedly connected between the bottom outlet of the mixing tank and the upper inlet of the first adsorption tower, a second mixed material inlet pipeline is fixedly connected between the first mixed material inlet pipeline and the upper inlet of the second adsorption tower, a third mixed material inlet pipeline is fixedly connected between the first mixed material inlet pipeline and the first adsorption tower and the upper inlet of the third adsorption tower, a first refined oil mixed liquid input pipeline is fixedly connected between the lower outlet of the first adsorption tower and the upper inlet of the first recovery solvent tank, a second refined oil mixed liquid input pipeline is fixedly connected between the first refined oil mixed liquid input pipeline and the lower outlet of the second adsorption tower, and a third mixed material input pipeline is fixedly connected between the first mixed material inlet pipeline and the first adsorption tower. The first refined oil mixed liquid input pipeline between the second refined oil mixed liquid input pipeline and the first recovery solvent tank is fixedly connected to the third refined oil mixed liquid input pipeline and the lower outlet of the third adsorption tower, the first dilution solvent return pipeline is fixedly connected between the upper outlet of the first recovery solvent tank and the upper inlet of the dilution solvent tank, the bottom outlet of the first recovery solvent tank is fixedly connected to the refined oil output pipeline, the bottom outlet of the first adsorption tower and the upper inlet of the second recovery solvent tank are fixedly connected to the first desorption aromatics pipeline, and the first desorption aromatics pipeline is fixedly connected to the bottom outlet of the second adsorption tower. A second desorption aromatics pipeline is fixedly connected, the second desorption aromatics pipeline and the bottom outlet of the third adsorption tower are fixedly connected with the third desorption aromatics pipeline, the bottom outlet of the second recovery solvent tank is fixedly connected with a polycyclic aromatics output pipeline, the upper outlet of the second recovery solvent tank and the lower inlet of the dilution solvent tank are fixedly connected with a second dilution solvent return pipeline, the top inlets of the first adsorption tower, the second adsorption tower and the third adsorption tower are fixedly connected with dilution solvent inlet pipelines, and the lower inlets of the first adsorption tower, the second adsorption tower and the third adsorption tower are respectively fixedly connected with nitrogen back-purge pipelines.

[0019] The following is a further optimization and / or improvement of the second technical solution of the above invention: The above-mentioned raw oil input pipeline is fixedly equipped with a raw oil delivery pump, the dilution solvent input pipeline is fixedly equipped with a dilution solvent delivery pump, and the first mixed material input pipeline between the second mixed material input pipeline and the first adsorption tower is fixedly equipped with a mixed material delivery pump.

[0020] The first adsorption tower is provided with a first catalyst bed, which is filled with a first mesoporous material; the second adsorption tower is provided with a second catalyst bed, which is filled with a second mesoporous material; the third adsorption tower is provided with a third catalyst bed, which is filled with a third mesoporous material.

[0021] The device of the present invention is simple, the operation method is simple and easy, the removal rate of polycyclic aromatic hydrocarbons in the obtained refined oil is high, and continuous feed of raw oil and removal of polycyclic aromatic hydrocarbons can be realized, and the dilution solvent can be recycled and reused, thereby reducing production costs and being easier to industrialize. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Attached Figure 1 This is a schematic diagram of the process flow of Example 9 of the present invention.

[0023] The codes in the accompanying drawings are: 1 is a raw oil tank, 2 is a dilution solvent tank, 3 is a mixing tank, 4 is a first adsorption tower, 5 is a second adsorption tower, 6 is a third adsorption tower, 7 is a first recovery solvent tank, 8 is a second recovery solvent tank, 9 is a raw oil input pipeline, 10 is a dilution solvent input pipeline, 11 is a first mixed material input pipeline, 12 is a second mixed material input pipeline, 13 is a third mixed material input pipeline, 14 is a first refined oil mixed liquid input pipeline, 15 is a second refined oil mixed liquid input pipeline, 16 is a third refined oil mixed liquid input pipeline. The input pipeline is 17, the first dilution solvent return pipeline, 18 is the refined oil output pipeline, 19 is the first desorption aromatics pipeline, 20 is the second desorption aromatics pipeline, 21 is the third desorption aromatics pipeline, 22 is the polycyclic aromatics output pipeline, 23 is the second dilution solvent return pipeline, 24 is the dilution solvent inlet pipeline, 25 is the raw oil delivery pump, 26 is the dilution solvent delivery pump, 27 is the mixture delivery pump, 28 is the first catalyst bed, 29 is the second catalyst bed, 30 is the third catalyst bed, and 31 is the nitrogen back-purge pipeline. DETAILED DESCRIPTION

[0024] The present invention is not limited by the following embodiments, and specific implementation methods can be determined according to the technical scheme of the present invention and actual conditions. Unless otherwise specified, the various chemical reagents and chemicals mentioned in the present invention are all known and commonly used chemical reagents and chemicals in the prior art. Unless otherwise specified, the equipment and devices used are all known and commonly used equipment and devices in the prior art.

[0025] The present invention will be further described below in conjunction with embodiments: Embodiment 1: As attached Figure 1As shown, the method for removing polycyclic aromatic hydrocarbons by adsorption of the mesoporous material is carried out according to the following steps: the first step is to mix the required amount of raw material oil with the diluent solvent to obtain a mixed raw material; the second step is that the mixed raw material enters the first adsorption tower 4 from top to bottom, and the polycyclic aromatic hydrocarbons in the mixed raw material are adsorbed and treated by the first mesoporous material in the first adsorption tower 4 to obtain a first refined oil mixed liquid, and after the first mesoporous material adsorbs the polycyclic aromatic hydrocarbons to saturation, the first adsorption tower 4 enters the waiting area; the third step is that the first refined oil mixed liquid flows out from the lower part of the first adsorption tower 4 and then undergoes a desolventizing treatment to obtain refined oil and the removed diluent solvent, wherein the diluent solvent is returned to the diluent solvent tank 2 for recycling, and the refined oil is recovered and collected; the In the fourth step, after the refined oil is recovered and collected, the first adsorption tower 4 in the waiting area is cut off from the original adsorption system and enters the desorption system. The first adsorption tower 4 performs desorption and back-blowing operations to obtain components rich in polycyclic aromatic hydrocarbons. In the fifth step, when the first adsorption tower 4 performs desorption and back-blowing operations, the mixed raw material enters the second adsorption tower 5 from top to bottom. The polycyclic aromatic hydrocarbons in the mixed raw material are adsorbed by the second mesoporous material in the second adsorption tower 5 to obtain a second refined oil mixed liquid. After the second mesoporous material is saturated with the polycyclic aromatic hydrocarbons, the second adsorption tower 5 enters the waiting area. In the sixth step, the second refined oil mixed liquid flows out from the lower part of the second adsorption tower 5 and is desolventized to obtain refined oil and the removed diluent solvent. Among them, the dilution solvent is returned to the dilution solvent tank 2 for recycling, and the refined oil is recovered and collected; in the seventh step, after the refined oil is recovered and collected, the second adsorption tower 5 in the waiting area is cut out from the original adsorption system and enters the desorption system, and the second adsorption tower 5 performs desorption and backblowing operations to obtain components rich in polycyclic aromatic hydrocarbons; in the eighth step, when the first adsorption tower 4 and the second adsorption tower 5 perform desorption and backblowing operations, the mixed raw material enters the third adsorption tower 6 from top to bottom, and the polycyclic aromatic hydrocarbons in the mixed raw material are adsorbed and treated by the third mesoporous material in the third adsorption tower 6 to obtain a third refined oil mixture. After the third mesoporous material is saturated with the polycyclic aromatic hydrocarbons, the third adsorption tower 6 enters the waiting area, and the first adsorption tower 4 and the second adsorption tower 5 perform desorption and backblowing operations. Tower 4 completes the desorption and backblowing operations, and the first adsorption tower 4 after desorption and backblowing is cut out of the desorption system and enters the waiting area; in the ninth step, the third refined oil mixture flows out from the lower part of the third adsorption tower 6 and is desolventized to obtain refined oil and removed dilution solvent, wherein the dilution solvent is returned to the dilution solvent tank 2 for recycling, and the refined oil is recovered and collected; in the tenth step, after the refined oil recovery and collection is completed, the third adsorption tower 6 in the waiting area is cut out from the original adsorption system and enters the desorption system, the third adsorption tower 6 performs desorption and backblowing operations to obtain components rich in polycyclic aromatic hydrocarbons, and at the same time, the first adsorption tower 4 in the waiting area is cut into the adsorption system, and the above-mentioned second to ninth steps are repeated.

[0026] Example 2: As an optimization of the above example, in the first step, the mass ratio of the feedstock oil to the dilution solvent is 1:0.8 to 1:1.05, wherein the feedstock oil is a heavy distillate oil and the dilution solvent is a non-polar hydrocarbon solvent.

[0027] Example 3: As an optimization of the above example, in the second step, the fifth step and the eighth step, the adsorption treatment time is 40 min to 120 min.

[0028] Example 4: As an optimization of the above example, the heavy distillate oil is heavy oil minus two-fraction oil or four-fraction oil, and the diluent solvent is petroleum ether or naphtha component at 90°C to 120°C, which is usually used as a water-carrying agent in the distillation process of crude oil.

[0029] The dilution solvent is a non-polar dilution solvent, and its main function is to dilute the viscosity of the raw material, reducing the viscosity of the feed by about 10 times or more, but can be normally recovered and utilized in industrial devices. According to needs, the dilution solvent in the present invention can be a commonly used dilution solvent, such as petroleum ether at 90°C to 120°C or naphtha components of a specific distillation range (180# or 200# dilution solvent oil).

[0030] Example 5: As an optimization of the above example, the average pore volume of the first mesoporous material, the second mesoporous material and the third mesoporous material are all 0.5 ml / g to 1.0 ml / g, and the specific surface area is 200 m 2 / g to 500m 2 / g, the adsorbents in the first mesoporous material, the second mesoporous material and the third mesoporous material are all hydrogenation catalyst protective agents, and the metal active components loaded by the hydrogenation catalyst protective agents are all double components composed of VIB group and VⅢ group metals.

[0031] Example 6: As an optimization of the above example, in the dual components consisting of group VIB and group VIII metals, the group VIB metal is 5% to 10% by mass percentage in terms of oxide content, and the group VIII metal is 1% to 5% by mass percentage in terms of oxide content.

[0032] The commercial brands of the hydrogenation catalyst protective agent in the present invention can be KG-1, KG-3, KFR-11, KFR-10, KFR-22, KFR-22, OptiTrap series Medallion, MroRing and Ring, LH04, HPS-02, and other commercial brands of demetallization, desiliconization and dearsenicization catalysts.

[0033] Example 7: As an optimization of the above example, the specific processes of the desorption and back-flushing operations of the first adsorption tower 4, the second adsorption tower 5 and the third adsorption tower 6 are: first, the desorbent is sequentially introduced into the first adsorption tower 4, the second adsorption tower 5 and the third adsorption tower 6 from bottom to top for desorption and desorption; then, industrial nitrogen with a volume concentration of 99.9% is used for back-flushing from bottom to top to obtain components rich in polycyclic aromatic hydrocarbons (abbreviated as PAHs).

[0034] Example 8: As an optimization of the above example, the desorption temperature is 90°C to 160°C, the desorption time is 50 min to 1 h, the back-purge time is 1.5 to 2 h, and the industrial nitrogen temperature is 90°C to 150°C.

[0035] In the present invention, the flow direction of the desorbent and the back-flushing gas is opposite to the flow direction of the materials in the adsorption tower, and the average pore size of the mesoporous material increases in a gradient from bottom to top.

[0036] Usually, the residence time of the mixed raw materials in the adsorption tower exceeds 40 minutes, and the maximum does not exceed 2 hours. The working cycle of the desorption tower is about 4 hours, including about 2 hours of nitrogen replacement and cooling and purging process.

[0037] Embodiment 9: As attached Figure 1As shown, the device for implementing the method of removing polycyclic aromatic hydrocarbons by adsorption of mesoporous materials comprises a raw oil tank 1, a dilution solvent tank 2, a mixing tank 3, a first adsorption tower 4, a second adsorption tower 5, a third adsorption tower 6, a first recovery solvent tank 7 and a second recovery solvent tank 8, a raw oil input pipeline 9 is fixedly connected between the lower outlet of the raw oil tank 1 and the upper inlet of the mixing tank 3, a dilution solvent input pipeline 10 is fixedly connected between the lower outlet of the dilution solvent tank 2 and the lower inlet of the mixing tank 3, a first mixed material inlet pipeline 11 is fixedly connected between the bottom outlet of the mixing tank 3 and the upper inlet of the first adsorption tower 4, and the first mixed material inlet pipeline 12 is fixedly connected between the bottom outlet of the mixing tank 3 and the upper inlet of the first adsorption tower 4. A second mixed material inlet pipeline 12 is fixedly connected between the pipeline 11 and the upper inlet of the second adsorption tower 5, a third mixed material inlet pipeline 13 is fixedly connected between the first mixed material inlet pipeline 11 between the second mixed material inlet pipeline 12 and the first adsorption tower 4 and the upper inlet of the third adsorption tower 6, a first refined oil mixed liquid input pipeline 14 is fixedly connected between the lower outlet of the first adsorption tower 4 and the upper inlet of the first recovery solvent tank 7, a second refined oil mixed liquid input pipeline 15 is fixedly connected between the first refined oil mixed liquid input pipeline 14 and the lower outlet of the second adsorption tower 5, and a second refined oil mixed liquid input pipeline 16 is fixedly connected between the second refined oil mixed liquid input pipeline 17 and the lower outlet of the second adsorption tower 5. A third refined oil mixed liquid input pipeline 16 is fixedly connected between the first refined oil mixed liquid input pipeline 14 between the first recovery solvent tank 5 and the first recovery solvent tank 7 and the lower outlet of the third adsorption tower 6, a first dilution solvent return pipeline 17 is fixedly connected between the upper outlet of the first recovery solvent tank 7 and the upper inlet of the dilution solvent tank 2, a refined oil output pipeline 18 is fixedly connected to the bottom outlet of the first recovery solvent tank 7, a first desorption aromatics pipeline 19 is fixedly connected between the bottom outlet of the first adsorption tower 4 and the upper inlet of the second recovery solvent tank 8, and a second desorption aromatics pipeline 19 is fixedly connected between the first desorption aromatics pipeline 19 and the bottom outlet of the second adsorption tower 5. A desorption aromatics pipeline 20, a third desorption aromatics pipeline 21 is fixedly connected between the second desorption aromatics pipeline 20 and the bottom outlet of the third adsorption tower 6, a polycyclic aromatics output pipeline 22 is fixedly connected to the bottom outlet of the second recovery solvent tank 8, a second dilution solvent return pipeline 23 is fixedly connected between the upper outlet of the second recovery solvent tank 8 and the lower inlet of the dilution solvent tank 2, the top inlets of the first adsorption tower 4, the second adsorption tower 5 and the third adsorption tower 6 are all fixedly connected with a dilution solvent inlet pipeline 24, and the lower inlets of the first adsorption tower 4, the second adsorption tower 5 and the third adsorption tower 6 are respectively fixedly connected with nitrogen back-purge pipelines 31.

[0038] Embodiment 10: As an optimization of the above embodiment 9, as shown in the attached Figure 1 As shown, a crude oil delivery pump 25 is fixedly installed on the crude oil input pipeline 9, a dilution solvent delivery pump 26 is fixedly installed on the dilution solvent input pipeline 10, and a mixture delivery pump 27 is fixedly installed on the first mixture input pipeline 11 between the second mixture input pipeline 12 and the first adsorption tower 4.

[0039] Embodiment 11: As an optimization of the above embodiment, as shown in the attached Figure 1 As shown, a first catalyst bed 28 is arranged in the first adsorption tower 4, and the first catalyst bed 28 is filled with a first mesoporous material. A second catalyst bed 29 is arranged in the second adsorption tower 5, and the second catalyst bed 29 is filled with a second mesoporous material. A third catalyst bed 30 is arranged in the third adsorption tower 6, and the third catalyst bed 30 is filled with a third mesoporous material.

[0040] As needed, the average pore sizes of the first mesoporous material on the first catalyst bed 28, the second mesoporous material on the second catalyst bed 29 and the third mesoporous material on the third catalyst bed 30 are all decreased in sequence according to a gradient. After entering each attached tower, the mixed raw materials pass through each catalyst bed in the order of decreasing average pore sizes of the mesoporous materials, and leave each adsorption tower at the end of each catalyst bed.

[0041] Using heavy oil minus two-fraction oil and minus four-fraction oil as raw materials, according to the process flow of Example 1, experiments on separation of aromatic hydrocarbons and enrichment of polycyclic aromatic hydrocarbons in lubricating oil components were carried out.

[0042] Feedstock oil: vacuum distillate oil (the vacuum distillation range determined by ASTM D1160 test method, the temperature range from the initial distillation point to the final distillation point is 350℃ to 500℃) from heavy crude oil (density greater than 0.92 g / ml), such as heavy oil with a distillation range of 350℃ to 420℃ minus two-fraction oil or heavy oil with a distillation range of 400℃ to 480℃ minus four-fraction oil; Dilution solvent: No. 120 dilution solvent oil or No. 180 dilution solvent oil; The adsorbents in the mesoporous materials in the first adsorption tower 4, the second adsorption tower 5, and the third adsorption tower 6 are commercially available hydrogenation catalyst protectors KG-1, KG-3, and KFR-11, respectively. The pore volume, specific surface area, and loading volume of the first mesoporous material, the second mesoporous material, and the third mesoporous material, and the catalyst sizes of hydrogenation catalyst protectors A, B, and C are shown in Table 1, respectively; the adsorbents in the comparative example are silica gels of 150 mesh and 200 mesh, respectively, which are fully loaded in the bed. The specific implementation method is as follows: Embodiment 12: As attached Figure 1As shown, the raw material oil: heavy oil minus distillation oil; diluent solvent: No. 120 diluent solvent oil. The mass ratio of the raw material oil to the diluent solvent is 1:0.8. After the two are mixed in the mixing tank 3, the temperature is about 50°C. According to the method of Example 1, the raw material oil delivery pump 25 is respectively sent to the first adsorption tower 4, the second adsorption tower 5 and the third adsorption tower 6. In the first adsorption tower 4, the second adsorption tower 5 and the third adsorption tower 6, the mixed raw material passes through the first catalyst bed 28, the second catalyst bed 29 and the third catalyst bed 30 of the first adsorption tower 4, the second adsorption tower 5 and the third adsorption tower 6 from top to bottom. The raw material oil stays in each adsorption tower for about 50 minutes, and finally flows out from the lower part of each adsorption tower to the first recovery solvent tank 7 to remove the diluent solvent (normal pressure distillation, the highest distillation temperature is about 200°C), and the refined oil from which the diluent solvent is removed is obtained, which is the final product; When the first adsorption tower 4, the second adsorption tower 5 and the third adsorption tower 6 are cut out from the original adsorption system and enter the desorption system, 120 solvent oil is used as the diluent solvent (desorbent), and passes through the first catalyst bed 28, the second catalyst bed 29 and the third catalyst bed 30 of the first adsorption tower 4, the second adsorption tower 5 and the third adsorption tower 6 from top to bottom, respectively. The desorption temperature is 90°C to 110°C, the volume ratio of the desorbent to the mesoporous material in the adsorption tower is 0.2:1, the desorption and elution time is about 1 hour, and finally 99.9% industrial nitrogen is used for back purge, the desorption tower is kept at 110°C for about 2h, and then cooled to 50°C for about 1h, and 8 kinds of polycyclic aromatic hydrocarbon components (i.e., 8PAHs) are obtained. The specific results are shown in Table 2.

[0043] Embodiment 13: As attached Figure 1 As shown, the raw material oil: heavy oil minus four fractions; diluent solvent: No. 180 diluent solvent oil. The mass ratio of the raw material oil to the diluent solvent is 1:1.05. After the two are mixed in the mixing tank 3, the temperature is about 60°C. According to the method of Example 1, the raw material oil delivery pump 25 is respectively sent to the first adsorption tower 4, the second adsorption tower 5 and the third adsorption tower 6. In the first adsorption tower 4, the second adsorption tower 5 and the third adsorption tower 6, the mixed raw material passes through the first catalyst bed 28, the second catalyst bed 29 and the third catalyst bed 30 of the first adsorption tower 4, the second adsorption tower 5 and the third adsorption tower 6 from top to bottom. The raw material oil stays in each adsorption tower for about 1 hour, and finally flows out from the lower part of each adsorption tower to the first recovery solvent tank 7 to remove the diluent solvent (normal pressure distillation, the highest distillation temperature is about 250°C), and the refined oil from which the diluent solvent is removed is obtained, which is the final product; When the first adsorption tower 4, the second adsorption tower 5 and the third adsorption tower 6 are cut out from the original adsorption system and enter the desorption system, 180 solvent oil is used as the diluent solvent (desorbent), and passes through the first catalyst bed 28, the second catalyst bed 29 and the third catalyst bed 30 of the first adsorption tower 4, the second adsorption tower 5 and the third adsorption tower 6 from top to bottom, respectively. The desorption temperature is 90°C to 110°C, the volume ratio of the desorbent to the mesoporous material in the adsorption tower is 0.3:1, the desorption and elution time is about 50min, and finally 99.9% industrial nitrogen is used for back-purging. The desorption tower is kept at 150°C for about 2 hours, and then cooled to 50°C for about 1 hour to obtain 8 kinds of polycyclic aromatic hydrocarbons (i.e., 8PAHs). The specific results are shown in Table 2.

[0044] Comparative Example 1: Raw oil: heavy oil minus distillation oil; diluent: No. 120 diluent solvent oil. The mass ratio of raw oil to diluent solvent is 1:0.8. After the two are mixed in the mixing tank 3, at about 50°C, they are sent to the adsorption tower through a metering pump. In the adsorption tower, the mixed raw materials pass through the adsorption tower (150 mesh silica gel bed) from top to bottom in sequence, and stay in the adsorption tower for about 50 minutes. Finally, they flow out from the bottom of the adsorption tower to remove the solvent (normal pressure distillation, the highest distillation temperature is about 200°C), and the refined oil from which the solvent is removed is obtained, which is the final product.

[0045] The adsorption tower was switched to desorption and desorption, and 120 diluted solvent oil was used as the desorbent to pass through the silica gel bed of the adsorption tower in turn. The desorption temperature was 90°C to 110°C, and the volume ratio of the desorbent to the filling material in the adsorption tower (including the adsorbed silica gel and the inert porcelain balls at both ends of the bed) was 0.2:1. The desorption and elution time was about 1 hour. Finally, it was purged with 99.9% industrial nitrogen. The desorption tower was kept at 90°C to 110°C for about 2 hours, and then cooled to 50°C for about 1 hour. The adsorbed refined oil and polycyclic aromatic hydrocarbon components obtained are shown in Table 2.

[0046] Comparative Example 2: Raw oil: heavy oil minus four fractions; diluent solvent: No. 180 diluent solvent oil. The mass ratio of raw oil to diluent solvent is 1:1.05. The two are mixed in a mixing tank 3 at a temperature of about 60°C. Then, adsorption is carried out in sequence according to the steps of Example 12, and the residence time in the adsorption tower (200 mesh silica gel bed) is about 1 hour. The desolvation process is atmospheric distillation, and the highest distillation temperature is 250°C, and a desolvated refined oil product is obtained.

[0047] The desorption operation is the same as that in Example 12, except that the desorption solvent is No. 180 dilution solvent oil, the desorption temperature is 150°C, the volume ratio of the desorbent to the filling material in the adsorption tower (including adsorbed silica gel and inert porcelain balls at both ends of the bed) is 0.3:1, the desorption elution time is 50 min, the industrial nitrogen is kept at 150°C, the purge time is 1.5 hours, and the temperature is lowered to 50°C for 1 hour. The adsorbed refined oil and polycyclic aromatic hydrocarbon components obtained are shown in Table 2.

[0048] As can be seen from Table 2, the method and apparatus for removing polycyclic aromatic hydrocarbons by adsorption using mesoporous materials of the present invention in Examples 12 and 13 significantly improve the removal rate of polycyclic aromatic hydrocarbons in the obtained refined oil by 10% to 12% compared with Comparative Examples 1 and 2 (full bed of silica gel), and there is almost no loss in the yield of refined oil.

[0049] As required, the pipelines and equipment of the apparatus for implementing the method for removing polycyclic aromatic hydrocarbons by adsorption of mesoporous materials may be provided with conventional valves, thermometers and pressure gauges known in the art according to production needs.

[0050] In summary, the device of the present invention is simple, the operation method is simple and easy, the removal rate of polycyclic aromatic hydrocarbons in the obtained refined oil is high, and continuous feed of raw oil and removal of polycyclic aromatic hydrocarbons can be achieved, and the dilution solvent can be recycled and reused, which reduces the production cost and is easier for industrial production.

[0051] The above technical features constitute the embodiments of the present invention, which have strong adaptability and implementation effect. Non-essential technical features can be added or reduced according to actual needs to meet the requirements of different situations.

Claims

1. A method for removing condensed aromatic hydrocarbons by adsorption of mesoporous materials, characterized in that The following steps are followed: first, the required amount of crude oil is mixed with a diluent solvent to obtain a mixed raw material; second, the mixed raw material enters the first adsorption tower from top to bottom, and the polycyclic aromatic hydrocarbons in the mixed raw material are adsorbed by the first mesoporous material in the first adsorption tower to obtain a first refined oil mixed liquid, and after the first mesoporous material is saturated with the polycyclic aromatic hydrocarbons, the first adsorption tower enters the waiting area; third, the first refined oil mixed liquid flows out from the lower part of the first adsorption tower and is desolventized to obtain refined oil and the removed diluent solvent, wherein the diluent solvent is returned to the diluent solvent tank for recycling, and the refined oil is recovered and collected; fourth, after the recovery and collection of the refined oil is completed, After that, the first adsorption tower in the waiting area is cut off from the original adsorption system and enters the desorption system, and the first adsorption tower performs desorption and back-blowing operations to obtain components rich in polycyclic aromatic hydrocarbons; in the fifth step, when the first adsorption tower performs desorption and back-blowing operations, the mixed raw material enters the second adsorption tower from top to bottom, and the polycyclic aromatic hydrocarbons in the mixed raw material are adsorbed by the second mesoporous material in the second adsorption tower to obtain a second refined oil mixed liquid. After the second mesoporous material is saturated with the polycyclic aromatic hydrocarbons, the second adsorption tower enters the waiting area; in the sixth step, the second refined oil mixed liquid flows out from the lower part of the second adsorption tower and is subjected to a desolventizing treatment to obtain refined oil and the removed dilution solvent, wherein the dilution solvent is returned to The mixed raw materials are recycled into the dilution solvent tank, and the refined oil is recovered and collected; in the seventh step, after the recovery and collection of the refined oil is completed, the second adsorption tower in the waiting area is cut out from the original adsorption system and enters the desorption system, and the second adsorption tower performs desorption and backwashing operations to obtain components rich in polycyclic aromatic hydrocarbons; in the eighth step, when the first adsorption tower and the second adsorption tower are performing desorption and backwashing operations, the mixed raw materials enter the third adsorption tower from top to bottom, and the polycyclic aromatic hydrocarbons in the mixed raw materials are adsorbed by the third mesoporous material in the third adsorption tower to obtain a third refined oil mixture. After the third mesoporous material is saturated with polycyclic aromatic hydrocarbons, the third adsorption tower enters the waiting area, and the first adsorption tower completes desorption at the same time. and back-blowing operation, the first adsorption tower after desorption and back-blowing is cut out of the desorption system and enters the waiting area; the ninth step, the third refined oil mixed liquid flows out from the lower part of the third adsorption tower and is subjected to desolventizing treatment to obtain refined oil and removed dilution solvent, wherein the dilution solvent is returned to the dilution solvent tank for recycling, and the refined oil is recovered and collected; the tenth step, after the recovery and collection of the refined oil is completed, the third adsorption tower in the waiting area is cut out from the original adsorption system and enters the desorption system, the third adsorption tower is subjected to desorption and back-blowing operations to obtain a component rich in polycyclic aromatic hydrocarbons, and at the same time the first adsorption tower in the waiting area is cut into the adsorption system, and the above-mentioned second to ninth steps are repeated.

2. The method for removing condensed aromatic hydrocarbons by adsorption of mesoporous materials according to claim 1, characterized in that In the first step, the mass ratio of the feedstock oil to the dilution solvent is 1:0.8 to 1:1.05, wherein the feedstock oil is a heavy distillate oil and the dilution solvent is a non-polar hydrocarbon solvent; or / and, in the second step, the fifth step and the eighth step, the adsorption treatment time is 40 min to 120 min.

3. The method for removing condensed aromatic hydrocarbons by adsorption of mesoporous materials according to claim 2, characterized in that Heavy distillate oil is heavy oil minus two-fraction oil or four-fraction oil, and the diluent solvent is petroleum ether or naphtha components at 90°C to 120°C.

4. The method for removing condensed aromatic hydrocarbons by adsorption by mesoporous materials according to claim 1, 2 or 3, characterized in that The average pore volume of the first mesoporous material, the second mesoporous material and the third mesoporous material are all 0.5 ml / g to 1.0 ml / g, and the specific surface area is 200 m 2 / g to 500m 2 / g, the adsorbents in the first mesoporous material, the second mesoporous material and the third mesoporous material are all hydrogenation catalyst protective agents, and the metal active components loaded by the hydrogenation catalyst protective agents are all double components composed of VIB group and VⅢ group metals.

5. The method for removing condensed aromatic hydrocarbons by adsorption of mesoporous materials according to claim 4, characterized in that In the dual components consisting of group VIB and group VIII metals, the group VIB metal is 5% to 10% by mass percentage in terms of oxide, and the group VIII metal is 1% to 5% by mass percentage in terms of oxide.

6. The method for removing condensed aromatic hydrocarbons by adsorption using a mesoporous material according to any one of claims 1 to 5, characterized in that The specific processes of desorption and backflushing operations of the first adsorption tower, the second adsorption tower and the third adsorption tower are: first, the desorbent is sequentially introduced into the first adsorption tower, the second adsorption tower and the third adsorption tower from bottom to top for desorption and desorption; then, industrial nitrogen with a volume concentration of 99.9% is used for backflushing from bottom to top to obtain components rich in polycyclic aromatic hydrocarbons.

7. The method for removing condensed aromatic hydrocarbons by adsorption of mesoporous materials according to claim 6, characterized in that The desorption temperature is 90°C to 160°C, the desorption time is 50min to 1h, the back-purge time is 1.5 to 2h, and the industrial nitrogen temperature is 90°C to 150°C.

8. A device for implementing the method for removing condensed aromatic hydrocarbons by adsorption of mesoporous materials according to any one of claims 1 to 7, characterized in that The invention comprises a raw oil tank, a dilution solvent tank, a mixing tank, a first adsorption tower, a second adsorption tower, a third adsorption tower, a first recovery solvent tank and a second recovery solvent tank, a raw oil input pipeline is fixedly connected between the lower outlet of the raw oil tank and the upper inlet of the mixing tank, a dilution solvent input pipeline is fixedly connected between the lower outlet of the dilution solvent tank and the lower inlet of the mixing tank, a first mixed material inlet pipeline is fixedly connected between the bottom outlet of the mixing tank and the upper inlet of the first adsorption tower, a second mixed material inlet pipeline is fixedly connected between the first mixed material inlet pipeline and the upper inlet of the second adsorption tower, a third mixed material inlet pipeline is fixedly connected between the first mixed material inlet pipeline between the second mixed material inlet pipeline and the first adsorption tower and the upper inlet of the third adsorption tower, a first refined oil mixed liquid input pipeline is fixedly connected between the lower outlet of the first adsorption tower and the upper inlet of the first recovery solvent tank, a second refined oil mixed liquid input pipeline is fixedly connected between the first refined oil mixed liquid input pipeline and the lower outlet of the second adsorption tower, and a second refined oil mixed liquid input pipeline is fixedly connected between the second refined oil mixed liquid input pipeline and the first recovery solvent tank. The third refined oil mixed liquid input pipeline is fixedly connected between the first refined oil mixed liquid input pipeline and the lower outlet of the third adsorption tower, the first dilution solvent return pipeline is fixedly connected between the upper outlet of the first recovery solvent tank and the upper inlet of the dilution solvent tank, the refined oil output pipeline is fixedly connected to the bottom outlet of the first recovery solvent tank, the first desorption aromatics pipeline is fixedly connected between the bottom outlet of the first adsorption tower and the upper inlet of the second recovery solvent tank, the second desorption aromatics pipeline is fixedly connected between the first desorption aromatics pipeline and the bottom outlet of the second adsorption tower, the third desorption aromatics pipeline is fixedly connected between the second desorption aromatics pipeline and the bottom outlet of the third adsorption tower, the bottom outlet of the second recovery solvent tank is fixedly connected with a condensed aromatics output pipeline, the upper outlet of the second recovery solvent tank and the lower inlet of the dilution solvent tank are fixedly connected with a second dilution solvent return pipeline, the top inlets of the first adsorption tower, the second adsorption tower and the third adsorption tower are all fixedly connected with dilution solvent inlet pipelines, and the lower inlets of the first adsorption tower, the second adsorption tower and the third adsorption tower are respectively fixedly connected with nitrogen back-purge pipelines.

9. The device according to claim 8, characterized in that A raw oil delivery pump is fixedly installed on the raw oil input pipeline, a dilution solvent delivery pump is fixedly installed on the dilution solvent input pipeline, and a mixture delivery pump is fixedly installed on the first mixture input pipeline between the second mixture input pipeline and the first adsorption tower.

10. The device according to claim 8 or 9, characterized in that A first catalyst bed is arranged in the first adsorption tower, and the first catalyst bed is filled with a first mesoporous material; a second catalyst bed is arranged in the second adsorption tower, and the second catalyst bed is filled with a second mesoporous material; a third catalyst bed is arranged in the third adsorption tower, and the third catalyst bed is filled with a third mesoporous material.

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