Low-temperature regeneration method of diesel oil adsorbent

Abstract

The invention discloses a low-temperature regeneration method of a diesel oil adsorbent. The method comprises the following steps: S1, purging a diesel oil raw material in a bed at a low temperature by adopting nitrogen; s2, carrying out low-temperature solvent washing regeneration on the inactivated diesel oil adsorbent in the bed layer by adopting a liquid-phase composite solvent; s3, carrying out low-temperature purging on the bed layer by adopting nitrogen, and removing the liquid-phase composite solvent in gaps of the bed layer; s4, carrying out high-temperature purging on the bed layer by adopting nitrogen, and removing the liquid-phase composite solvent in the inactivated diesel oil adsorbent; and S5, carrying out low-temperature purging on the bed layer by adopting nitrogen, reducing the temperature of the bed layer to an adsorption temperature, and completing the steps of adsorbent regeneration and the like. The process flow is simple, the adsorption performance reduction amplitude after regeneration is low, and the regeneration stability is high.

Description

Technical Field

[0001] The invention relates to a process for regenerating an adsorbent, and in particular to a low-temperature regeneration method for a diesel adsorbent. Background Art

[0002] The adsorption method for removing aromatics from diesel has been studied for many years, but strong polar impurities such as sulfur and nitrogen compounds and colloids in diesel can cause the adsorbent to be deactivated and lose its selective adsorption capacity for aromatics. At present, the adsorbent regeneration process still has problems such as difficulty in adsorbent regeneration, decreased adsorption performance after regeneration, and high energy consumption of the regeneration process.

[0003] CN111996030A discloses a process for in-situ regeneration of a simulated moving bed adsorbent, which uses a weak polar solvent and a strong polar solvent to perform steam in-situ regeneration of the deactivated adsorbent in the simulated moving bed device. However, there are problems such as high regeneration temperature, narrow application range and low capacity after regeneration due to weak / strong polarity.

[0004] CN107790112A discloses an activation method for removing oxygen-containing compounds from low-carbon olefins. The method removes low-carbon oxygen-containing compounds on the adsorbent through a step-by-step temperature-raising and purging process to avoid coking and carbon deposition on the adsorbent. However, the processing range is relatively narrow and only low-carbon oxygen-containing compounds such as methanol and dimethyl ether can be processed.

[0005] CN107321337A discloses an adsorbent regeneration system and an adsorbent regeneration method, wherein the regeneration system of the method mainly includes a regeneration furnace, a condenser, a gas-liquid separator and a vacuum pump. The adsorbent is placed in a regeneration furnace at 420-460°C, and nitrogen is introduced through the air inlet pipe for purging for 1-2 hours, and then regenerated by nitrogen roasting. CN108795476A discloses a gasoline desulfurization adsorbent regeneration process, which is preliminarily regenerated by a fluidized bed, and then placed in a high-temperature heating furnace, oxygen is introduced, heated to 500-600°C, roasted for 2-5 hours, and the adsorbent regeneration is completed. Both of the above methods use high-temperature roasting to remove the inactivated substances on the adsorbent, and the regeneration efficiency is high, but there is a risk of the adsorbent structure being destroyed, and the energy consumption is high.

[0006] The existing adsorbent regeneration processes are mainly based on high-temperature calcination off-vessel regeneration and high-temperature gas in-situ regeneration processes. The off-vessel regeneration has problems such as frequent loading and unloading of agents, high energy consumption, and large consumption. The high-temperature gas in-situ regeneration process is complicated. After regeneration, the adsorption capacity and adsorption separation performance are significantly reduced, making it difficult to meet the separation standards. Summary of the invention

[0007] The present invention is proposed to solve the problems existing in the existing diesel adsorbent regeneration method, such as high temperature, high energy consumption, poor stability, serious attenuation of adsorption performance after regeneration, and low adsorption capacity. Its purpose is to provide a low-temperature regeneration method for diesel adsorbent.

[0008] The present invention is achieved through the following technical solutions:

[0009] A low temperature regeneration method for a diesel adsorbent comprises the following steps:

[0010] S1. Use nitrogen to purge diesel raw materials in the bed at low temperature;

[0011] S2, using a liquid composite solvent to perform low-temperature solvent flushing and regeneration of the deactivated diesel adsorbent in the bed;

[0012] S3, using nitrogen to purge the bed at low temperature to remove the liquid composite solvent in the gap between the beds;

[0013] S4, using nitrogen to purge the bed at high temperature to remove the liquid composite solvent in the deactivated diesel adsorbent;

[0014] S5. Use nitrogen to purge the bed at low temperature to reduce the bed temperature to the adsorption temperature to complete the regeneration of the adsorbent.

[0015] The beneficial effects of the present invention are:

[0016] The present invention provides a low-temperature regeneration method for a diesel adsorbent, which has low regeneration temperature and low process energy consumption; the liquid-phase composite solvent can efficiently remove poisons from the diesel adsorbent, and has a low agent-to-oil ratio; a minimum azeotrope can be formed inside the liquid-phase composite solvent, and the regeneration temperature is greatly reduced during the N2 high-temperature purge process, while the composite solvent is completely removed from the adsorbent, and the regeneration efficiency is high; the adsorption capacity (mass) loss of the diesel adsorbent after the initial regeneration is ≤3%, and the adsorption capacity (mass) loss is ≤20% within 20 regenerations. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 It is a schematic diagram of the structure of the system adopted by the low-temperature regeneration method of the diesel adsorbent of the present invention.

[0018] in:

[0019] 1. Flushing liquid tank; 2. Solvent regeneration tower; 3. Pump No. Ⅰ; 4. Flushing solvent collection tank; 5. Adsorption device; 6. N2 heating furnace; 7. Diesel raw material collection tank; 8. N2 flowmeter; 9. Pump No. Ⅱ.

[0020] For ordinary technicians in this field, other relevant drawings can be obtained based on the above drawings without any creative work. DETAILED DESCRIPTION

[0021] In order to enable those skilled in the art to better understand the technical solution of the present invention, the technical solution of the present invention is further described below with reference to the accompanying drawings and through specific implementation methods.

[0022] like Figure 1 As shown, a method for low-temperature regeneration of a diesel adsorbent comprises the following steps:

[0023] S1. Use nitrogen to purge diesel raw materials in the bed at low temperature

[0024] The nitrogen raw material is passed through the N2 flow meter 8 and the N2 heating furnace 6 to perform low-temperature purge on the deactivated diesel adsorbent in the adsorption device 5, and the diesel raw material in the adsorption device 5 enters the collection tank 7 for collection;

[0025] The temperature of the nitrogen low-temperature purge in step S1 is 40°C to 80°C, and the nitrogen purge space velocity is 100h -1 ~500h -1 The nitrogen purge pressure is 0.1MPa to 0.3MPa, and the purge time is 30min to 150min; preferably, the nitrogen low-temperature purge space velocity is 150h -1 ~350h -1 , N2 purge pressure is 0.1MPa~0.2MPa, and purge time is 40min~80min.

[0026] S2. Use liquid composite solvent to perform low temperature solvent washing and regeneration of deactivated diesel adsorbent in the bed

[0027] The liquid phase composite solvent in the flushing liquid tank 1 is used by pump II 9 to perform low temperature solvent flushing and regeneration on the deactivated adsorbent in the adsorption device 5;

[0028] The temperature of the flushing and regeneration in step S2 is 40°C to 80°C; the flushing space velocity of the liquid phase composite solvent is 0.1h - ~2.0h -1 , the flushing pressure is 0.1MPa~0.3MPa, the volume ratio of the liquid composite solvent to the deactivated diesel adsorbent is (1.0~2.5):1; the liquid composite solvent in step S2 includes aromatic hydrocarbons and oxygen-containing compounds, and the aromatic hydrocarbons are used as co-solvents to dissolve the oxygen-containing compounds and diesel. The boiling point of the aromatic hydrocarbons is ≤150°C, the boiling point of the oxygen-containing compounds is ≤90°C, and the aromatic hydrocarbons can form a minimum azeotrope with the oxygen-containing compounds. The aromatic hydrocarbon content in the liquid composite solvent is 10%~30%.

[0029] S3. Use nitrogen to purge the bed at low temperature to remove the liquid composite solvent in the gap between the beds.

[0030] The nitrogen raw material is passed through the N2 flow meter 8 and the N2 heating furnace 6 to perform low-temperature purge on the adsorbent after flushing in the adsorption device 5, and the flushing solvent in the adsorption device 5 enters the collection tank 4 for collection;

[0031] In step S3, the temperature of the bed layer purged with nitrogen is 40°C to 80°C, and the nitrogen purging space velocity is 100h-1 ~500h -1 The N2 purge pressure is 0.1MPa to 0.3MPa, and the purge time is 30min to 150min; preferably, the nitrogen low-temperature purge space velocity is 150h -1 ~350h -1 , N2 purge pressure is 0.1MPa~0.2MPa, and purge time is 40min~80min.

[0032] S4. Use nitrogen to purge the bed at high temperature to remove the liquid composite solvent in the deactivated diesel adsorbent.

[0033] The nitrogen raw material is passed through the N2 flow meter 8 and the N2 heating furnace 6 to perform high-temperature purge on the adsorbent after flushing in the adsorption device 5 to remove the residual flushing solvent on the adsorbent;

[0034] In step S4, the temperature of the bed layer purged with nitrogen is 100°C to 160°C, and the nitrogen purging space velocity is 100h -1 ~500h -1 The nitrogen purge pressure is 0.1MPa to 0.3MPa, and the purge time is 30min to 150min; preferably, the nitrogen high-temperature purge space velocity is 300h -1 ~450h -1 The nitrogen purge pressure is 0.15MPa~0.25MPa, and the purge time is 50min~120min.

[0035] S5. Use nitrogen to purge the bed at low temperature to reduce the bed temperature to the adsorption temperature to complete the adsorbent regeneration.

[0036] The nitrogen raw material is passed through the N2 flow meter 8 and the N2 heating furnace 6 to purge the adsorbent after high-temperature purge in the adsorption device 5 at low temperature, thereby reducing the bed temperature to the adsorption temperature and completing the regeneration of the adsorbent;

[0037] In step S5, the temperature of the bed layer purged with nitrogen is 40°C to 80°C, and the nitrogen purging space velocity is 100h -1 ~500h -1 The N2 purge pressure is 0.1MPa to 0.3MPa, and the purge time is 30min to 150min; preferably, the nitrogen low-temperature purge space velocity is 150h -1 ~350h -1 , N2 purge pressure 0.1MPa~0.2MPa, purge time 40min~80min.

[0038] S6. Recycling of composite solvent containing diesel raw materials through distillation separation

[0039] The composite solvent containing diesel raw materials enters the distillation tower 2 from the collection tank 4 through the No. Ⅰ pump 3 to regenerate the flushing solvent, and the liquid composite solvent is extracted from the top of the distillation tower 2 and returned to the flushing liquid tank 1.

[0040] In the step S6, during the distillation and solvent recovery process, the theoretical number of distillation tower stages is 30 to 50, the reflux ratio is 0.3 to 1.2, the solvent mass loss is ≤0.1%, and the mass purity of the recovered solvent is ≥95%.

[0041] The adsorption device 5 is filled with deactivated diesel adsorbent; the diesel adsorbent is any one or a combination of molecular sieves, silica gel, alumina or amorphous aluminum silicate; the distillation range of the diesel raw material treated with the diesel adsorbent is 150°C to 365°C; the adsorption device 5 is any one of a fixed bed, a moving bed or a simulated moving bed.

[0042] The calculation formula of the adsorption capacity (mass) of the adsorbent in the following examples is as follows:

[0043] Adsorption capacity (mass) = diesel feed mass flow rate × aromatic content × breakthrough time / adsorbent mass;

[0044] Adsorption capacity (mass) loss after regeneration = (adsorption capacity (mass) of fresh adsorbent - adsorption capacity (mass) after regeneration) / adsorption capacity (mass) of fresh adsorbent × 100%.

[0045] Example 1

[0046] The distillation range of diesel raw material is 175℃~340℃, the deactivated adsorbent is silica gel, the adsorption device is a fixed bed, and the method for low-temperature regeneration of the adsorbent includes the following steps:

[0047] S1. Nitrogen is used to purge diesel fuel in the bed at low temperature, the purge temperature is 40℃, and the air velocity is 150h -1 , purge pressure 0.1MPa, purge time 40min;

[0048] S2. Use liquid composite solvent to regenerate the deactivated adsorbent in the bed by low-temperature solvent flushing. The composite solvent is prepared by mixing 10% benzene and 90% ethanol. The boiling point of benzene is 80.1℃, the boiling point of ethanol is 78.3℃, and the flushing space velocity is 0.2h -1 , flushing pressure 0.1MPa, flushing temperature 40℃, the volume ratio of flushing solvent to deactivated adsorbent is 2.5:1;

[0049] S3. Use N2 for low temperature purging, purging temperature 40℃, air velocity 150h -1 , purge pressure 0.1MPa, purge time 40min;

[0050] S4. Use N2 for high temperature purging, purging temperature 100℃, air velocity 300h -1, purge pressure 0.15MPa, purge time 50min;

[0051] S5. Use N2 for low temperature purge, purge temperature 40℃, air velocity 150h -1 , purge pressure 0.1MPa, purge time 60min;

[0052] S6. The composite solvent containing diesel raw materials is recycled by distillation separation, the distillation tower has 30 theoretical stages and the reflux ratio is 0.45.

[0053] Results of Example 1: The adsorption capacity (mass) lost 2.5% after the first regeneration, 19.5% after regeneration 19 times, 21.4% after regeneration 21 times, 0.02% mass loss during solvent recovery, and the mass purity of the recovered solvent was 96.5%.

[0054] Example 2

[0055] The diesel raw material has a distillation range of 160°C to 360°C, the deactivated adsorbent is a molecular sieve, the adsorption device is a simulated moving bed, and the method for low-temperature regeneration of the adsorbent includes the following steps:

[0056] S1. Nitrogen is used to purge diesel fuel in the bed at low temperature, the purge temperature is 60℃, and the air velocity is 350h -1 , purge pressure 0.2MPa, purge time 80min;

[0057] S2. Use liquid composite solvent to regenerate the deactivated adsorbent in the bed by low-temperature solvent flushing. The composite solvent is prepared by 30% toluene and 70% acetone. The boiling point of toluene is 110.6℃, the boiling point of acetone is 56.5℃, and the flushing space velocity is 1.5h -1 , flushing pressure 0.2MPa, flushing temperature 80℃, the volume ratio of flushing solvent to deactivated adsorbent is 1.0:1;

[0058] S3. Use N2 for low temperature purge, purge temperature 60℃, air velocity 350h -1 , purge pressure 0.2MPa, purge time 80min;

[0059] S4. Use N2 for high temperature purge, the purge temperature is 120℃, the air velocity is 450h -1 , purge pressure 0.2MPa, purge time 120min;

[0060] S5. Use N2 for low temperature purging, purging temperature 60℃, air velocity 350h -1 , purge pressure 0.2MPa, purge time 80min;

[0061] S6. The composite solvent containing diesel raw materials is recycled by distillation separation. The theoretical number of distillation towers is 35 and the reflux ratio is 0.6.

[0062] Results of Example 2: The adsorption capacity (mass) lost 1.3% after the first regeneration, 18.8% after 19 regenerations, 20.7% after 21 regenerations, 0.05% mass loss during the solvent recovery process, and the mass purity of the recovered solvent was 97.3%.

[0063] Example 3

[0064] The diesel raw material has a distillation range of 150°C to 365°C, the deactivated adsorbent is alumina, the adsorption device is a moving bed, and the method for low-temperature regeneration of the adsorbent comprises the following steps:

[0065] S1. Nitrogen is used to purge diesel fuel in the bed at low temperature, with a purge temperature of 80°C and an air velocity of 200h -1 , purge pressure 0.1MPa, purge time 60min;

[0066] S2. Use liquid composite solvent to regenerate the deactivated adsorbent in the bed by low-temperature solvent flushing. The composite solvent is compounded with 20% ethylbenzene and 80% isopropanol. The boiling point of ethylbenzene is 136.2℃, the boiling point of isopropanol is 82.5℃, and the flushing space velocity is 2h. -1 , flushing pressure 0.15MPa, flushing temperature 80℃, and the volume ratio of flushing solvent to deactivated adsorbent is 1.5:1;

[0067] S3. Use N2 for low temperature purging, purging temperature 80℃, air velocity 200h -1 , purge pressure 0.15MPa, purge time 70min;

[0068] S4. Use N2 for high temperature purging, the purging temperature is 150℃, the air velocity is 400h -1 , purge pressure 0.2MPa, purge time 100min;

[0069] S5. Use N2 for low temperature purging, purging temperature 80℃, air velocity 200h -1 , purge pressure 0.15MPa, purge time 70min;

[0070] S6. The composite solvent containing diesel raw materials is recycled by distillation separation, the distillation tower has 45 theoretical stages and the reflux ratio is 1.0.

[0071] Results of Example 3: After the first regeneration, the adsorption capacity (mass) lost 3.7%, after 19 regenerations, the adsorption capacity (mass) lost 18.9%, after 21 regenerations, the adsorption capacity (mass) lost 21.0%, the mass loss during the solvent recovery process was 0.1%, and the mass purity of the recovered solvent was 98.1%.

[0072] Example 4

[0073] The diesel raw material has a distillation range of 200°C to 350°C, the deactivated adsorbent is amorphous aluminum silicate, the adsorption device is a fixed bed, and the method for low-temperature regeneration of the adsorbent includes the following steps:

[0074] S1. Nitrogen is used to purge diesel fuel in the bed at low temperature, the purge temperature is 40℃, and the air velocity is 175h -1 , purge pressure 0.5MPa, purge time 50min;

[0075] S2. Use liquid composite solvent to regenerate the deactivated adsorbent in the bed by low-temperature solvent flushing. The composite solvent is prepared by mixing 15% benzene and 85% methanol. The boiling point of benzene is 80.1℃, the boiling point of methanol is 64.8℃, and the flushing space velocity is 0.5h -1 , flushing pressure 0.15MPa, flushing temperature 40℃, and the volume ratio of flushing solvent to deactivated adsorbent is 1.4:1;

[0076] S3. Use N2 for low temperature purge, purge temperature 40℃, air velocity 175h -1 , purge pressure 0.5MPa, purge time 50min;

[0077] S4. Use N2 for high temperature purge, purge temperature 110℃, air velocity 370h -1 , purge pressure 0.15MPa, purge time 70min;

[0078] S5. Use N2 for low temperature purge, purge temperature 40℃, air velocity 175h -1 , purge pressure 0.5MPa, purge time 50min;

[0079] S6. The composite solvent containing diesel raw materials is recycled by distillation separation, the distillation tower has 45 theoretical stages and the reflux ratio is 0.3.

[0080] Results of Example 4: The adsorption capacity (mass) lost 1.0% after the first regeneration, 18.3% after 19 regenerations, 20.4% after 21 regenerations, 0.06% mass loss during the solvent recovery process, and the mass purity of the recovered solvent was 95.9%.

[0081] Comparative Example 1

[0082] The distillation range of diesel raw material is 150°C to 365°C, the deactivated adsorbent is silica gel, the adsorption device is a fixed bed, and the method for low-temperature regeneration of the adsorbent comprises the following steps:

[0083] S1. Nitrogen is used to purge diesel fuel in the bed at low temperature, the purge temperature is 30℃, and the air velocity is 100h -1 , purge pressure 0.5MPa, purge time 30min;

[0084] S2. Use liquid composite solvent to regenerate the deactivated adsorbent in the bed by low-temperature solvent flushing. The composite solvent is made of 50% n-hexane and 50% benzene. The boiling point of benzene is 80.1℃, the boiling point of n-hexane is 69℃, and the flushing space velocity is 2.5h -1 , flushing pressure 0.4MPa, flushing temperature 100℃, and the volume ratio of flushing solvent to deactivated adsorbent is 3.0:1;

[0085] S3. Use N2 for low temperature purging, purging temperature 30℃, air velocity 100h -1 , purge pressure 0.5MPa, purge time 30min;

[0086] S4. Use N2 for high temperature purging, the purging temperature is 200℃, the air velocity is 200h -1 , purge pressure 0.5MPa, purge time 200min;

[0087] S5. Use N2 for low temperature purging, purging temperature 30℃, air velocity 100h -1 , purge pressure 0.5MPa, purge time 30min;

[0088] S6. The composite solvent containing diesel raw materials is recycled by distillation separation, the distillation tower has 25 theoretical stages and the reflux ratio is 0.2.

[0089] Results of comparative example 1: the adsorption capacity (mass) lost 10.4% after the first regeneration, 29.7% after 19 regenerations, 34.2% after 21 regenerations, 0.3% mass loss during the solvent recovery process, and the mass purity of the recovered solvent was 93.5%.

[0090] Table 1 Comparison of regeneration results

[0091]

[0092]

[0093] As shown in Table 1, according to the method of the present invention, the adsorption capacity (mass) of the diesel adsorbent decreases by ≤5% after the first regeneration, and decreases by ≤20% after 19 regenerations, and the mass loss of the solvent during the solvent recovery process is ≤0.1%, and the mass purity of the solvent is ≥95%. It can be seen that the present application has the characteristics of high regeneration efficiency, low regeneration temperature, and low regeneration solvent loss.

[0094] The present invention flushes and regenerates the deactivated adsorbent by a polar composite solvent at a relatively low temperature, and further removes the solvent by N2 purging, so as to achieve the purpose of complete regeneration of the adsorbent, and the flushing solvent can be recycled by distillation separation. The whole process has the characteristics of low temperature and low pressure, low agent-oil ratio, and stable regeneration performance. The mass loss of adsorption capacity after regeneration is less than 3%, and the solvent mass recovery rate is more than 99.9%.

[0095] The applicant declares that the above is only a specific implementation mode of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily thought of by those skilled in the art within the technical scope disclosed by the present invention shall fall within the protection scope and disclosure scope of the present invention.

Claims

1. A low temperature regeneration method for a diesel adsorbent, characterized in that: The following steps are involved: S1. Use nitrogen to purge diesel raw materials in the bed at low temperature; S2, using a liquid composite solvent to perform low-temperature solvent flushing and regeneration of the deactivated diesel adsorbent in the bed; S3, using nitrogen to purge the bed at low temperature to remove the liquid composite solvent in the gap between the beds; S4, using nitrogen to purge the bed at high temperature to remove the liquid composite solvent in the deactivated diesel adsorbent; S5. Use nitrogen to purge the bed at low temperature to reduce the bed temperature to the adsorption temperature to complete the regeneration of the adsorbent.

2. The low temperature regeneration method of diesel adsorbent according to claim 1, characterized in that: The temperature of the nitrogen low-temperature purge in step S1 is 40°C to 80°C, and the nitrogen purge space velocity is 100h -1 ~500h -1 The nitrogen purge pressure is 0.1MPa to 0.3MPa, and the purge time is 30min to 150min; preferably, the nitrogen low-temperature purge space velocity is 150h -1 ~350h -1 , N2 purge pressure is 0.1MPa~0.2MPa, and purge time is 40min~80min.

3. The low temperature regeneration method of diesel adsorbent according to claim 1, characterized in that: The temperature of the flushing and regeneration in step S2 is 40°C to 80°C; the flushing space velocity of the liquid phase composite solvent is 0.1h - ~2.0h -1 , the flushing pressure is 0.1MPa~0.3MPa, the volume ratio of the liquid composite solvent to the deactivated diesel adsorbent is (1.0~2.5):1; the liquid composite solvent in step S2 includes aromatic hydrocarbons and oxygen-containing compounds, the boiling point of aromatic hydrocarbons is ≤150°C, the boiling point of oxygen-containing compounds is ≤90°C, and aromatic hydrocarbons can form a minimum azeotrope with oxygen-containing compounds, and the aromatic hydrocarbon content in the liquid composite solvent is 10%~30%.

4. The low temperature regeneration method of diesel adsorbent according to claim 1, characterized in that: In step S3, the temperature of the bed layer purged with nitrogen is 40°C to 80°C, and the nitrogen purging space velocity is 100h -1 ~500h -1 The N2 purge pressure is 0.1MPa to 0.3MPa, and the purge time is 30min to 150min; preferably, the nitrogen low-temperature purge space velocity is 150h -1 ~350h -1 , N2 purge pressure is 0.1MPa~0.2MPa, and purge time is 40min~80min.

5. The low temperature regeneration method of diesel adsorbent according to claim 1, characterized in that: In step S4, the temperature of the bed layer purged with nitrogen is 100°C to 160°C, and the nitrogen purging space velocity is 100h -1 ~500h -1 The nitrogen purge pressure is 0.1MPa to 0.3MPa, and the purge time is 30min to 150min; preferably, the nitrogen high-temperature purge space velocity is 300h -1 ~450h -1 The nitrogen purge pressure is 0.15MPa~0.25MPa, and the purge time is 50min~120min.

6. The low temperature regeneration method of diesel adsorbent according to claim 1, characterized in that: In step S5, the temperature of the bed layer purged with nitrogen is 40°C to 80°C, and the nitrogen purging space velocity is 100h -1 ~500h -1 The N2 purge pressure is 0.1MPa to 0.3MPa, and the purge time is 30min to 150min; preferably, the nitrogen low-temperature purge space velocity is 150h -1 ~350h -1 , N2 purge pressure 0.1MPa~0.2MPa, purge time 40min~80min.

7. The low temperature regeneration method of diesel adsorbent according to claim 1, characterized in that: The diesel adsorbent is any one or a combination of molecular sieves, silica gel, alumina or amorphous aluminum silicate; the distillation range of the diesel raw material treated by the diesel adsorbent is 150°C to 365°C.

8. The low temperature regeneration method of diesel adsorbent according to claim 1, characterized in that: The step S6 also includes recycling the composite solvent containing the diesel raw material through distillation separation.

9. The low temperature regeneration method of diesel adsorbent according to claim 8, characterized in that: In the step S6, during the distillation and solvent recovery process, the theoretical number of distillation towers is 30 to 50, the reflux ratio is 0.3 to 1.2, the mass loss of the solvent is ≤0.1%, and the mass purity of the recovered solvent is ≥95%.

10. The low temperature regeneration method of diesel adsorbent according to claim 1, characterized in that: The low-temperature regeneration method is applied to the regeneration of diesel adsorbent in any one of a fixed bed, a moving bed or a simulated moving bed.

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