Discharge treatment agents and their applications in coking and blockage of hydrogenation units

Abstract

This invention discloses a catalyst unloading treatment agent and its application for coking and blockage in hydrogenation units. The unloading treatment agent includes solvents, carbonates, and sulfur-containing compounds, with the solvent being water and / or an organic solvent. A method for catalyst unloading in hydrogenation units due to coking and blockage is also provided. When catalyst needs to be unloaded due to coking and blockage, the aforementioned unloading treatment agent is introduced into the reactor for settling treatment when the reactor temperature is not higher than 60°C, and then unloading begins. Further, the unloaded catalyst is mixed with a treatment liquid for further treatment. After treatment, it is further dried, sieved, and then backfilled into the reactor for reuse. Using the unloading treatment agent of this invention can significantly reduce dust pollutants generated during the skimming process, accelerate the suction unloading speed, effectively reduce the catalyst breakage rate during unloading, and significantly reduce the reactor pressure drop after restarting.

Description

Technical Field

[0001] This invention belongs to the field of petrochemicals and relates to a catalyst unloading treatment agent for coking and blockage of hydrogenation units and its application, specifically to a fixed-bed hydrogenation catalyst unloading treatment agent and its application. Background Technology

[0002] As crude oil becomes increasingly heavy, the quality of feedstocks processed by refining companies continues to deteriorate, mainly manifested in higher final boiling points and increased levels of sulfur and nitrogen impurities, as well as metal and mechanical impurities. This trend poses a significant challenge to the long-term operation of hydrotreating units.

[0003] In recent years, hydrogenation has become a major technological route for refining and chemical enterprises to utilize heavy feedstocks for high value-added purposes. However, when using fixed-bed hydrogenation, metals and mechanical impurities in the feedstock accumulate in the reactor, increasing the reactor pressure drop. Once the pressure drop exceeds the reactor's mechanical tolerance limit, the unit must be shut down for troubleshooting and catalyst skimming. In recent years, the frequency of catalyst skimming in hydrogenation units has increased significantly.

[0004] Currently, existing catalyst removal operations involve unloading the catalyst from the top of the catalyst to the point of concentrated pressure drop from the reactor, sieving it on-site to remove accumulated dust as much as possible, and then refilling the catalyst back into the reactor to reduce the pressure drop and ensure safe and stable operation of the unit. However, the conventional unloading process generates severe dust, greatly affecting the health of operators and causing serious environmental pollution. Furthermore, during the catalyst extraction process, collisions and friction cause significant catalyst breakage, reducing the amount of catalyst that can be refilled and making it difficult to control the reactor pressure drop after refilling. Conventional sieving can only remove some of the dust and impurities between catalyst particles, failing to remove scale deposited inside the catalyst channels. This results in a persistently high reactor pressure drop after catalyst removal and refilling, severely impacting the long-term operation of the unit.

[0005] CN1376765A discloses a method for unloading catalysts in a petrochemical plant. The method involves using an oil-based agent composed of a solvent and a film-forming agent, with the film-forming agent added at a concentration of 0.5% to 2.0% (volume fraction). During plant shutdown, the solvent is introduced and circulated for 10 to 30 hours, after which the catalyst is immersed in the oil-based agent for several hours. This results in the formation of a special oil film on the catalyst surface, which helps reduce dust generation during unloading. However, this method is not suitable for the decanting process. The catalyst unloaded after introducing the oil-based agent cannot be screened and backfilled on-site due to the presence of the oil film, and it remains on the surface of the reactor where catalyst was not unloaded, affecting the catalyst's performance. Furthermore, impurities deposited inside the catalyst channels cannot be removed, resulting in a high pressure drop in the reactor after backfilling.

[0006] CN110653009A discloses a method for online activity recovery and unloading of a catalyst in heavy oil hydrotreating. The patent is characterized by gradually replacing the heavy oil feedstock with a carrier oil containing additives, specifically naphthalene compounds and monocyclic aromatic hydrocarbons. This patent allows for in-unit catalyst activity recovery and accelerates catalyst unloading to reduce downtime. However, this patent is not applicable to the decanting stage of the unit; the unloaded catalyst, wetted with oil, cannot be sieved on-site, and the pressure drop in the reactor after backfilling cannot be reduced.

[0007] CN212017740U discloses a reactor unloading system, which consists of a hydraulic station outside the reactor, a catalyst separation device, a controller, and a suction device. The hydraulic station is connected to the controller via a cable to achieve unmanned and fully automatic unloading, which can reduce labor costs and eliminate the harm to unloading personnel caused by dust during the unloading process. Summary of the Invention

[0008] To address the shortcomings of existing technologies, this invention provides a decanting agent for coking and clogging in hydrogenation units and its application. By using this decanting agent, dust contaminants generated during the tipping process can be significantly reduced, the decanting speed can be accelerated, and the catalyst breakage rate during decanting can be effectively reduced. Simultaneously, the internal pore structure of the catalyst can be restored to a certain extent, significantly reducing the reactor pressure drop after restarting. This solves the problems of large dust volume, slow decanting rate, severe catalyst pulverization, and limited pressure drop reduction effect in existing technologies.

[0009] The first aspect of the present invention provides an unloading treatment agent, which includes a solvent, a carbonate and a sulfur-containing compound; based on the weight of the unloading treatment agent, the carbonate content is 0.1wt% to 4.0wt%, preferably 0.88wt% to 2.5wt%; the sulfur-containing inorganic compound content is 0.8wt% to 5wt%, preferably 1.2wt% to 2.5wt%.

[0010] Furthermore, in the above-mentioned unloading agent, the solvent is water and / or an organic solvent, which can be one or more of alcohols, ethers, esters, ketones, hydrocarbons, and naphtha. The number of carbon atoms in the alcohols, ethers, esters, ketones, and hydrocarbons can be 1 to 12, preferably 1 to 6; even further, the alcohols can be at least one of methanol, ethanol, ethylene glycol, propanol, glycerol, butanol, butanediol, pentanol, 2-propanol, 2-methyl-1-propanol, and 2-butanol, preferably propanol; the hydrocarbons are at least one of benzene, toluene, xylene, n-pentane, n-hexane, heptane, octane, nonane, decane, and petroleum ether; the ethers are diethyl ether, tetrahydrofuran, 1... The ester compound is at least one selected from 4-dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, ethylene glycol propyl ether, diethylene glycol butyl ether, diethylene glycol dibutyl ether, propylene glycol ether, propylene glycol methyl ether, propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol ethyl ether, dipropylene glycol diethyl ether, butyl ether, dipropylene glycol butyl ether, methyl tert-butyl ether, dipentyl ether, isopentyl ether, and hexyl ether; the ester compound is at least one selected from methyl acetate, ethyl acetate, and butyl acetate. The naphtha is light naphtha with a final boiling point not exceeding 98°C, preferably not exceeding 70°C.

[0011] Furthermore, in the above-mentioned unloading treatment agent, the carbonate is one or more of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium carbonate, ammonium bicarbonate, potassium carbonate, and potassium bicarbonate, preferably ammonium carbonate.

[0012] Furthermore, in the above-mentioned unloading treatment agent, the sulfur-containing compound may be selected from one or more of sodium hydrosulfide, sodium sulfide, sodium thiosulfate, ammonium thiosulfate, potassium sulfide, and potassium hydrosulfide, preferably sodium hydrosulfide and / or ammonium thiosulfate.

[0013] Furthermore, the solvent, carbonate, and sulfur-containing compound are mixed evenly to obtain the unloading treatment agent of the present invention.

[0014] The second aspect of the present invention provides a method for unloading catalyst when coking and blockage occur in a hydrogenation unit. When the hydrogenation unit needs to unload the catalyst due to coking and blockage, the above-mentioned unloading treatment agent is introduced into the reactor and allowed to stand for 0.1 to 5 hours, preferably 0.5 to 1 hour, when the reactor temperature is not greater than 60°C, preferably not greater than 50°C, before unloading begins.

[0015] Furthermore, in the above-mentioned catalyst unloading method for coking and blockage in the hydrogenation unit, the injection amount of unloading agent is determined according to the catalyst volume in the reactor. Generally, the volume of unloading agent is 50% to 120% of the catalyst volume in the reactor, preferably 80% to 105%.

[0016] Furthermore, in the catalyst unloading method for coking and blockage in the above-mentioned hydrogenation unit, the unloading can be any of the unloading methods commonly used in the industry in this field, such as the unloading process using negative pressure suction, with a pressure of -0.1 MPa to -1.0 MPa, preferably -0.2 MPa to -0.5 MPa.

[0017] The third aspect of the present invention provides a method for catalyst recycling when coking and blockage occur in a hydrogenation unit. When the reactor temperature is not greater than 60°C, preferably not greater than 50°C, the above-mentioned unloading treatment agent is introduced into the reactor and allowed to stand for 0.1 to 5 hours, preferably 0.5 to 1 hour, before unloading is started. The unloaded catalyst is mixed with the treatment liquid for further treatment. After treatment, it is further dried, sieved, and then backfilled into the reactor for use.

[0018] Furthermore, in the catalyst recycling method when the hydrogenation unit cokes and gets clogged, the treatment liquid is an acidic solvent, specifically at least one of hydrochloric acid ethanol solution, hydrochloric acid propanol solution, hydrochloric acid butanol solution, and nitric acid ethanol solution; preferably hydrochloric acid ethanol solution, wherein the mass fraction of hydrochloric acid in the hydrochloric acid ethanol solution is 0.5% to 5.2%, and more preferably 0.75% to 1.5%.

[0019] Furthermore, in the method for catalyst recycling when coking and blockage occur in the hydrogenation unit, the temperature for treating the discharged catalyst with the treatment liquid is 50℃~160℃, preferably 80℃~125℃, and the treatment time is 10min~120min, preferably 20min~60min.

[0020] Furthermore, in the catalyst recycling method when the hydrogenation unit is coking or blocked, the unloaded catalyst can be mixed with the treatment liquid using any of the existing methods that can achieve liquid-solid two-phase mixing, such as impregnation, spray impregnation, or spraying.

[0021] Furthermore, in the method for catalyst recycling when coking and blockage occur in the hydrogenation unit, the amount of treatment liquid used is 5% to 34% of the volume of the unloading treatment agent, preferably 12% to 25%.

[0022] Furthermore, in the method for catalyst recycling when coking and blockage occur in the hydrogenation unit, the drying temperature is 60–200°C, preferably 90–125°C, and the drying time is 0.5–10 h, preferably 1.0–3.0 h.

[0023] Furthermore, in the method of catalyst recycling when coking and blockage occur in the hydrogenation unit, sieving and backfilling can be carried out using any of the existing methods in the art. Specifically, the catalyst can be sieved by a vibrating sieve device equipped with a screen to remove dust and other impurities. After that, the sieved catalyst is hoisted to the top of the reactor using a hopper and the catalyst is loaded using ordinary loading or dense phase loading.

[0024] Furthermore, in the method for catalyst recycling when coking and blockage occur in the hydrotreating unit, the catalyst is any one of various types of hydrotreating catalysts used in fixed-bed hydrotreating processes for hydrocarbon-containing materials, including hydrorefining catalysts, hydrocracking catalysts, hydromodification catalysts, hydroisomerization catalysts, hydrodemetallization catalysts, hydrodesulfurization catalysts, hydrodenitrogenation catalysts, and hydrodecarbonization catalysts. The hydrocarbon-containing material can be any one of diesel oil, wax oil, residual oil, coal tar, catalytic slurry, etc.

[0025] Compared with the prior art, the unloading treatment agent and its application in the coking and blockage of the hydrogenation unit of the present invention have the following advantages:

[0026] 1. The unloading agent used in this invention can completely encapsulate the catalyst to be unloaded and seal the dust between the catalyst particles in the liquid phase, thereby greatly reducing the dust during the unloading process.

[0027] 2. In this invention, the introduction of the unloading treatment agent makes the catalyst, powder and treatment agent a continuous phase. The pressure required to unload the catalyst by negative pressure suction at the top of the reactor is greatly reduced. At the same time, the formation of the continuous phase also greatly avoids collisions between catalysts, which greatly reduces the catalyst breakage rate during the unloading process and thus improves the unloading rate.

[0028] 3. The unloading treatment agent and treatment liquid provided by this invention are used in conjunction. The unloading treatment agent and treatment liquid penetrate into the pores of the catalyst and decompose and volatilize under subsequent operating conditions. This allows the internal pores of the catalyst to recover to a certain extent, thereby improving the catalyst activity and ensuring that the reactor pressure drop meets requirements after backfilling. This solves the problem that existing unloading sieving technology can only remove dust between catalyst particles, but cannot remove blockages in the catalyst pores, resulting in a still large bed pressure drop after backfilling.

[0029] 4. The skimming process differs significantly from conventional catalyst unloading. Skimming only removes a portion of the catalyst from the upper part of the reactor, leaving a large amount of catalyst in the lower part. Existing unloading technologies use additives containing a large amount of heavy components that form a film on the catalyst surface, adversely affecting catalyst activity. The unloading treatment agent provided by this invention not only avoids adverse effects on the catalyst remaining in the reactor, but also ensures that the physicochemical properties of the catalyst remaining in the reactor are significantly improved during subsequent use due to the CO2, NH3, and H2S gases generated by the decomposition of the unloading treatment agent. Detailed Implementation

[0030] The following examples further illustrate the function and effect of the method of the present invention, but the following examples do not constitute a limitation on the method of the present invention.

[0031] Unless otherwise expressly stated, throughout the specification and claims, the term "comprising" or its variations such as "including" or "comprises" shall be understood to include the stated elements or components without excluding other elements or other components.

[0032] In this paper, for the sake of convenience, spatial relative terms such as “below,” “under,” “down,” “above,” “above,” “up,” etc., are used to describe the relationship between one element or feature and another element or feature.

[0033] In this document, the terms "first," "second," etc., are used to distinguish two different elements or parts, and are not used to define specific positions or relative relationships. In other words, in some embodiments, the terms "first," "second," etc., can also be used interchangeably.

[0034] In this document, all numeric values ​​of parameters (e.g., quantity or condition) should be understood to be modified by the term “about” in all cases, regardless of whether “about” actually appears before the numeric value.

[0035] Example 1

[0036] The decapsulation process was carried out on the wax oil hydrotreating reactor, which has three beds (totaling 180m³). 3 The pressure drop is concentrated in the first bed layer, which is filled with 60m³ of material. 3The FF-24 (cloverleaf) catalyst was used. The first bed of catalyst was unloaded from the reactor and screened for backfilling. The unloading treatment agents used included 46t of light naphtha (final boiling point 68℃); 2.3t of propanol; 0.46t of potassium carbonate; 0.92t of ammonium bicarbonate; and 0.69t of sodium hydrosulfide. The unloading treatment agents were introduced into the reactor after the reactor was purged with N2 and the temperature dropped to no more than 50℃ (reactor outlet valve closed). Unloading began 1 hour after the unloading treatment agents were injected into the reactor. The unloading process used negative pressure suction technology at a pressure of -0.2 MPa. The unloaded catalyst was placed in a heated stirred tank with a low-speed stirring function. The stirred tank was equipped with a spray system at the top, and a hydrochloric acid ethanol solution with a mass fraction of 0.75% was injected into the stirred tank. The spraying rate was 10 liters / min, the spraying stirring time was 20 min, the temperature inside the reactor was 90℃, and then the treated catalyst was dried at 95℃ for 3 h, sieved using a vibrating sieve device, and finally backfilled into the reactor for use. The reaction results are shown in Table 1.

[0037] Example 2

[0038] A skimming process was performed on the hydrocracking pretreatment reactor, which has three beds (totaling 200m³). 3 The pressure drop is concentrated in the first bed layer, which is filled with 80m³ of material. 3 The FF-66 (toothed ball) catalyst was used. The first bed of catalyst was unloaded from the reactor and screened for backfilling. The unloading treatment agent used included 56t of light naphtha (final boiling point 88℃), 1.56t of propanol, 0.33t of potassium carbonate, 0.63t of ammonium bicarbonate, and 0.98t of sodium hydrosulfide. The unloading treatment agent was introduced into the reactor after the reactor was purged with N2 and the temperature dropped to no more than 60℃ (reactor outlet valve closed). Unloading began 0.5h after the unloading treatment agent was injected into the reactor. The unloading process used negative pressure suction technology at a pressure of -0.5MPa. The unloaded catalyst was placed in a heated stirred tank with a low-speed stirring function. The stirred tank was equipped with a spray system at the top, and a hydrochloric acid ethanol solution with a mass fraction of 1.5% was injected into the stirred tank. The spray rate was 20 L / min, and the spraying and stirring time was 30min. The temperature inside the reactor was 112℃. The treated catalyst was then dried at 120℃ for 1 hour, sieved using a vibrating sieve device, and finally backfilled into the reactor for use. The reaction results are shown in Table 1.

[0039] Example 3

[0040] The hydrocracking pretreatment reactor was subjected to a skimming process. The reactor has three beds (totaling 210m³). 3 The pressure drop is concentrated in the second bed layer, and the first bed layer is filled with 80m³ of material. 3 The FF-66 (toothed ball) catalyst, with a second bed packing of 60m³ 3The FF-66 (cloverleaf) catalyst was used. The first and second bed layers of catalyst were unloaded from the reactor and sieved before backfilling. The unloading treatment agents used included 140t of water, 2.70t of ethanol, 1.86t of ethylene glycol, 1.39t of potassium carbonate, 0.77t of ammonium bicarbonate, and 3.85t of sodium hydrosulfide. The unloading treatment agents were introduced into the reactor after N2 purging to a temperature no higher than 60°C (reactor outlet valve closed). Unloading began 0.75 hours after the treatment agents were injected. The unloading process employed negative pressure suction technology at a pressure of -0.35 MPa. The unloaded catalyst was placed in a heated stirred tank equipped with a low-speed stirring function. A spray system was installed at the top of the stirred tank, and a hydrochloric acid-ethanol solution with a hydrochloric acid mass fraction of 1.2% was injected into the stirred tank. The spraying rate was 25 L / min, the spraying stirring time was 60 min, the reactor temperature was 125℃, and then the treated catalyst was dried at 100℃ for 2 h, sieved using a vibrating sieve device, and finally backfilled into the reactor for use. The reaction results are shown in Table 1.

[0041] Comparative Example 1

[0042] The decapsulation process was carried out on the wax oil hydrotreating reactor, which has three beds (totaling 180m³). 3 The pressure drop is concentrated in the first bed layer, which is filled with 60m³ of material. 3 The FF-24 (cloverleaf) catalyst is used. After the first bed of catalyst is unloaded from the reactor, it is sieved for separation and then directly backfilled. The unloading, sieving, and backfilling techniques and methods commonly used in industry are adopted.

[0043] Comparative Example 2

[0044] The hydrocracking pretreatment reactor was subjected to a skimming process. The reactor has three beds (totaling 210m³). 3 The pressure drop is concentrated in the second bed layer, and the first bed layer is filled with 80m³ of material. 3 The FF-66 (toothed ball) catalyst, with a second bed packing of 60m³ 3 The FF-66 (cloverleaf) catalyst was used. The first and second bed catalysts were unloaded from the reactor and screened for backfilling. A mixed solvent, using light diesel oil as the solvent and propylene glycol butyl ether as the solute (2.9% by volume), was introduced into the reactor and circulated for 24 hours. After soaking for 8 hours, the first and second bed catalysts were unloaded from the reactor and screened for backfilling. Industrially accepted unloading and screening / backfilling techniques and methods were employed.

[0045] Comparative Example 3

[0046] The decapsulation process was carried out on the wax oil hydrotreating reactor, which has three beds (totaling 180m³). 3The pressure drop is concentrated in the first bed layer, which is filled with 60m³ of material. 3 The FF-24 (cloverleaf) catalyst was used. The first bed of catalyst was unloaded from the reactor and sieved before backfilling. The unloading treatment agents used included 46t of light naphtha (final boiling point 68℃) and 2.3t of propanol. The unloading treatment agents were introduced into the reactor after the reactor was purged with N2 until the reactor's highest temperature did not exceed 50℃ (reactor outlet valve closed). Unloading began 1 hour after the unloading treatment agents were injected into the reactor. The unloading process employed negative pressure suction technology at a pressure of -0.2MPa. The unloaded catalyst was placed in a heated stirred tank equipped with a low-speed stirring function. A spray system was installed at the top of the stirred tank, and a hydrochloric acid-ethanol solution with a mass fraction of 0.75% was injected into the stirred tank. The spray rate was 10 L / min, the spraying and stirring time was 20 min, and the tank temperature was 90℃. The treated catalyst was then dried at 95℃ for 3 h, sieved using a vibrating sieve, and finally backfilled into the reactor for reuse. The reaction results are shown in Table 1.

[0047] Comparative Example 4

[0048] A skimming process was performed on the hydrocracking pretreatment reactor, which has three beds (totaling 200m³). 3 The pressure drop is concentrated in the first bed layer, which is filled with 80m³ of material. 3 The FF-66 (toothed ball) catalyst was used. The first bed of catalyst was unloaded from the reactor and screened for backfilling. The unloading treatment agents used included 56t of light naphtha (final boiling point 88℃), 1.56t of propanol, 0.33t of potassium carbonate, and 0.63t of ammonium bicarbonate. The unloading treatment agents were introduced into the reactor after the reactor was purged with N2 and the temperature dropped to no more than 60℃ (reactor outlet valve closed). Unloading began 0.5h after the unloading treatment agents were injected into the reactor. The unloading process used negative pressure suction technology at a pressure of -0.5MPa. The unloaded catalyst was placed in a heated stirred tank with a low-speed stirring function. The stirred tank was equipped with a spray system at the top, and a hydrochloric acid ethanol solution with a mass fraction of 1.5% was injected into the stirred tank. The spray rate was 20 L / min, and the spraying and stirring time was 30 min. The temperature inside the reactor was 112℃. The treated catalyst was then dried at 120℃ for 1 hour, sieved using a vibrating sieve device, and finally backfilled into the reactor for use. The reaction results are shown in Table 1.

[0049] Comparative Example 5

[0050] The hydrocracking pretreatment reactor was subjected to a skimming process. The reactor has three beds (totaling 210m³). 3 The pressure drop is concentrated in the second bed layer, and the first bed layer is filled with 80m³ of material. 3 The FF-66 (toothed ball) catalyst, with a second bed packing of 60m³ 3The FF-66 (cloverleaf) catalyst was used. The first and second bed layers of catalyst were unloaded from the reactor and sieved before backfilling. The unloading treatment agents used included 140t of water, 2.70t of ethanol, 1.86t of ethylene glycol, and 3.85t of sodium hydrosulfide. The unloading treatment agents were introduced into the reactor after N2 purging to a temperature no higher than 60°C (reactor outlet valve closed). Unloading began 0.75 hours after the unloading treatment agents were injected into the reactor. The unloading process employed negative pressure suction technology at a pressure of -0.35 MPa. The unloaded catalyst was placed in a heated stirred tank equipped with a low-speed stirring function. A spray system was installed at the top of the stirred tank, and a hydrochloric acid-ethanol solution with a hydrochloric acid mass fraction of 1.2% was injected into the stirred tank. The spraying rate was 25 L / min, the spraying stirring time was 60 min, the reactor temperature was 125℃, and then the treated catalyst was dried at 100℃ for 2 h, sieved using a vibrating sieve device, and finally backfilled into the reactor for use. The reaction results are shown in Table 1.

[0051] Table 1. Reaction Results of Examples

[0052]

[0053] Table 2 Results of the comparative examples

[0054]

[0055] Data analysis of Examples 1-3 and Comparative Examples 1-5 shows that by using the unloading treatment agent and backfilling method provided by the present invention, dust generation during the unloading process can be effectively reduced, minimizing the harm of dust to operators and the natural environment. The time from unloading to catalyst backfilling is shortened to about half of the original time, and the catalyst breakage rate is significantly reduced. This not only saves on catalyst procurement costs but also reduces the reactor pressure drop after catalyst backfilling, while the catalyst activity is fully restored, bringing significant economic benefits to the refinery.

Claims

1. A method for catalyst recycling when coking and blockage occur in a hydrogenation unit, wherein when the reactor temperature is not greater than 60°C, a discharge treatment agent is introduced into the reactor and allowed to stand for 0.1 to 5 hours before discharge is started. The discharged catalyst is mixed with the treatment liquid for further treatment. After treatment, it is further dried, sieved, and then returned to the reactor for use. The unloading agent includes solvents, carbonates, and sulfur-containing compounds, wherein the solvent is water and / or an organic solvent; wherein, Based on the weight of the unloading agent, the carbonate content is 0.1wt% to 4.0wt%, and the sulfur compound content is 0.8wt% to 5wt%. The carbonate is one or more of sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate, ammonium carbonate, and ammonium bicarbonate, and the sulfur compound is selected from one or more of sodium hydrosulfide, sodium sulfide, sodium thiosulfate, ammonium thiosulfate, potassium sulfide, and potassium hydrosulfide. The treatment solution is an acidic solvent, and the acidic solvent is at least one of hydrochloric acid ethanol solution, hydrochloric acid propanol solution, hydrochloric acid butanol solution, and nitric acid ethanol solution.

2. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 1, characterized in that: When the reactor temperature is not higher than 50℃, the unloading treatment agent is introduced into the reactor and allowed to stand for 0.5h to 1h before unloading begins.

3. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 1, characterized in that: Based on the weight of the unloading agent, the carbonate content is 0.88wt% to 2.5wt%; the sulfur compound content is 1.2wt% to 2.5wt%.

4. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 1, characterized in that: The organic solvent is one or more of the following: alcohols, ethers, esters, ketones, and hydrocarbons.

5. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 1, characterized in that: The organic solvent is naphtha.

6. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 4, characterized in that: Alcohols, ethers, esters, ketones, and hydrocarbons have 1 to 12 carbon atoms.

7. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 6, characterized in that: Alcohols, ethers, esters, ketones, and hydrocarbons have 1 to 6 carbon atoms.

8. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 4 or 6, characterized in that: The alcohols are at least one of methanol, ethanol, ethylene glycol, propanol, glycerol, butanol, butanediol, pentanol, 2-propanol, and 2-butanol.

9. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 4 or 6, characterized in that: The alcohol is propanol.

10. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 4 or 6, characterized in that: The hydrocarbon compound is at least one of benzene, toluene, xylene, n-pentane, n-hexane, heptane, octane, nonane, decane, and petroleum ether.

11. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 4 or 6, characterized in that: The ether compounds are at least one of the following: diethyl ether, tetrahydrofuran, 1,4-dioxane, ethylene glycol dimethyl ether, diethylene glycol dimethyl ether, ethylene glycol diethyl ether, diethylene glycol diethyl ether, ethylene glycol propyl ether, diethylene glycol butyl ether, diethylene glycol dibutyl ether, propylene glycol methyl ether, propylene glycol dimethyl ether, dipropylene glycol dimethyl ether, dipropylene glycol ethyl ether, dipropylene glycol diethyl ether, butyl ether, dipropylene glycol butyl ether, methyl tert-butyl ether, dipentyl ether, isopentyl ether, and hexyl ether.

12. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 4 or 6, characterized in that: The ester compound is at least one of methyl acetate, ethyl acetate, and butyl acetate.

13. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 5, characterized in that: The final boiling point of light naphtha is not higher than 98℃.

14. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 5, characterized in that: The final boiling point of light naphtha is not higher than 70℃.

15. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 1, characterized in that: The carbonate is ammonium carbonate.

16. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 1, characterized in that: The sulfur-containing compounds are sodium hydrosulfide and / or ammonium thiosulfate.

17. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 1, characterized in that: The volumetric amount of the unloading agent is 50% to 120% of the catalyst volume in the reactor.

18. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 1, characterized in that: The volume of the unloading agent is 80% to 105% of the catalyst volume in the reactor.

19. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 1, characterized in that: The agent is unloaded using a negative pressure suction process, with a pressure of -0.1 MPa to -1.0 MPa during negative pressure suction.

20. The method for catalyst recycling in the event of coking and blockage of a hydrogenation unit according to claim 1, characterized in that: The agent is unloaded using a negative pressure suction process, with a pressure of -0.2 MPa to -0.5 MPa during negative pressure suction.

21. The method for catalyst recycling in the event of coking and blockage of the hydrogenation unit according to claim 1, characterized in that: The treatment solution is a hydrochloric acid-ethanol solution, in which the mass fraction of hydrochloric acid is 0.5% to 5.2%.

22. The method for catalyst recycling in the event of coking and blockage of the hydrogenation unit according to claim 1, characterized in that: The treatment solution is a hydrochloric acid-ethanol solution, in which the mass fraction of hydrochloric acid is 0.75% to 1.5%.

23. The method for catalyst recycling in the event of coking and blockage of the hydrogenation unit according to claim 1, characterized in that: The temperature for treating the unloaded catalyst with the treatment liquid is 50℃~160℃, and the treatment time is 10min~120min.

24. The method for catalyst recycling in the event of coking and blockage of the hydrogenation unit according to claim 1, characterized in that: The temperature for treating the unloaded catalyst with the treatment liquid is 80℃~125℃, and the treatment time is 20min~60min.

25. The method for catalyst recycling in the event of coking and blockage of the hydrogenation unit according to claim 1, characterized in that: The amount of treatment fluid used is 5% to 34% of the volume of the unloading treatment agent.

26. The method for catalyst recycling in the event of coking and blockage of the hydrogenation unit according to claim 1, characterized in that: The amount of treatment fluid used is 12% to 25% of the volume of the unloading treatment agent.

27. The method for catalyst recycling in the event of coking and blockage of the hydrogenation unit according to claim 1, characterized in that: The drying temperature is 60–200℃, and the drying time is 0.5–10 hours.

28. The method for catalyst recycling in the event of coking and blockage of the hydrogenation unit according to claim 1, characterized in that: The drying temperature is 90–125℃, and the drying time is 1.0–3.0 h.

29. The method for catalyst recycling in the event of coking and blockage of the hydrogenation unit according to claim 1, characterized in that: The catalysts are various types of hydrogenation catalysts used in fixed-bed hydrogenation processes for hydrocarbon-containing materials.

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