Ex-situ regeneration method of hydrofining catalyst

Abstract

The invention discloses an ex-situ regeneration method of a hydrofining catalyst, and relates to the technical field of hydrogenation catalyst application, the method comprises the steps of pretreatment, limited scorching treatment, activation treatment and the like, the limited scorching treatment and the activation treatment are integrated, and compared with a distributed operation mode, the limited scorching treatment and the activation treatment are integrated into a whole; the method has the advantages of simple operation, lower energy consumption cost and solution cost, shortened regeneration time, realization of efficient regeneration and activity recovery, low cost, short period and good activity recovery.

Description

Technical Field

[0001] The invention relates to the technical field of hydrogenation catalyst application, and in particular to an ex-situ regeneration method of a hydrogenation refining catalyst. Background Art

[0002] Hydrotreating catalysts play a vital role in the petrochemical industry. They can significantly improve product quality and production efficiency. However, as the use time increases, the catalysts will gradually lose their activity and need to be regenerated. As an efficient and environmentally friendly catalyst regeneration technology, the ex situ regeneration method has been widely used in recent years.

[0003] The main reasons for the deactivation of hydrotreating catalysts include the following:

[0004] Surface carbon deposition: During the hydrogenation process, the cracking of hydrocarbons in the crude oil and the condensation of unstable compounds will generate coke on the catalyst surface, covering the metal active centers and blocking the micropores.

[0005] Metal deposition: Metals in the crude oil (such as Fe, Ni, V, Ca, etc.) exist in the form of soluble organic metal compounds. After decomposition during the hydrogenation process, they are deposited on the catalyst surface and block the micropores; As, Pb, Na, etc. react with the active center of the catalyst and destroy the catalyst carrier structure.

[0006] Poison adsorption: Certain substances (such as arsenic) are adsorbed on the active center to form compounds that are inactive to the hydrogenation reaction, resulting in permanent deactivation of the catalyst.

[0007] Existing off-site regeneration methods for hydrogenation catalysts, such as patent No. 201110027356.0, disclose a novel method for regenerating hydrogenation catalysts. The regeneration method can effectively control the burning of deposited carbon on the deactivated catalyst to be regenerated, retain the intrinsic carbon, minimize the aggregation of active metals, and restore its strength, specific surface area, and pore volume, laying the foundation for chemical treatment. The burnt regeneration agent is further chemically treated and activated (saturated impregnation-drying) with organic compounds (containing organic complexes) to supplement the useful organic additives that have been burned during the burning process and interact with the active metals, so that some of the aggregated active metals can be redispersed and converted into highly active reaction centers during the sulfurization process, so that the activity of the catalyst is well restored.

[0008] The above method combines conventional char regeneration and chemical treatment activation, but has problems such as high cost and long process cycle. At the same time, there is still room for improvement in the pretreatment details. Summary of the invention

[0009] The purpose of the present invention is to overcome the deficiencies of the above-mentioned technology and provide an ex situ regeneration method for a hydrotreating catalyst, which has the advantages of low cost, short cycle and good activity recovery.

[0010] In order to achieve the above-mentioned invention object, the technical solution adopted by the present invention is:

[0011] A method for regenerating a hydrotreating catalyst off-site, characterized in that it comprises the following specific steps:

[0012] (1) Pretreatment: The deactivated hydrogenation catalyst is placed in a vibrating screen for screening, and the deactivated hydrogenation catalyst is simultaneously purged from top to bottom by means of compressed air to remove carbon powder and impurities on its surface to obtain a deactivated hydrogenation catalyst with a moderate particle size;

[0013] (2) Limited charring treatment: the deactivated hydrogenation catalyst with moderate particle size obtained in step (1) is spread on the conveying mesh belt of the regeneration mesh belt kiln and conveyed into the furnace, which is sequentially composed of three temperature sections: low-temperature preheating section - sulfur burning and charring section - cooling section, wherein the temperature of the low-temperature preheating section is set to 250°C, the residence time of the deactivated hydrogenation catalyst in the low-temperature preheating section is 3 hours, the temperature of the sulfur burning and charring section is set to 380°C, the residence time of the deactivated hydrogenation catalyst in the low-temperature preheating section is 3 hours, an inert gas is introduced into the cooling section as cooling gas, the residence time of the deactivated hydrogenation catalyst in the cooling section is 2 hours, and the deactivated hydrogenation catalyst is discharged from the furnace after being cooled to room temperature;

[0014] (3) Activation treatment: A regeneration liquid spray system and a turning device are provided in the cooling section of the regeneration mesh belt kiln. When the deactivated hydrogenation catalyst is cooled to 200°C in the cooling section, the regeneration liquid spray system is started to spray the regeneration liquid evenly on the surface of the deactivated hydrogenation catalyst. At the same time, the turning device is started to turn the deactivated hydrogenation catalyst on the transmission mesh belt so that the regeneration liquid can be fully sprayed on the surface of the deactivated hydrogenation catalyst. The spraying is stopped after the deactivated hydrogenation catalyst is cooled to 150°C, and the residual heat is used to dry the deactivated hydrogenation catalyst to obtain an activated hydrogenation catalyst.

[0015] A further improvement of the present invention is that the jet pressure of the compressed air in step (1) is 0.45 MPa and the mesh number of the vibrating screen is 18 meshes.

[0016] A further improvement of the present invention is that an acid liquid spraying system and a turning device are provided in the low temperature preheating section of the regeneration mesh belt kiln in step (2). When the deactivated hydrogenation catalyst is delivered to the low temperature preheating section, the acid liquid spraying system is started to spray the acid liquid evenly on the surface of the deactivated hydrogenation catalyst. At the same time, the turning device is started to turn the deactivated hydrogenation catalyst on the transmission mesh belt so that the acid liquid can be fully sprayed on the surface of the deactivated hydrogenation catalyst. The amount of acid liquid used per kg of deactivated hydrogenation catalyst is 10 L and the spraying time is 5 min. The deactivated hydrogenation catalyst is treated with acid liquid as an auxiliary agent, which can reduce the interaction force between the metal components and carbon deposits in the catalyst and the carrier. At the same time, the temperature set in the low temperature preheating section can achieve a drying effect, and there is no need to dry the deactivated hydrogenation catalyst after the acid liquid treatment.

[0017] A further improvement of the present invention is that the acid solution is one or a mixture of hydrochloric acid, nitric acid, acetic acid, oxalic acid, phosphoric acid, citric acid, tartaric acid, and malic acid.

[0018] A further improvement of the present invention is that the regeneration liquid in step (3) is an aqueous solution composed of nitrilotriacetic acid, diammonium hydrogen phosphate and deionized water.

[0019] A further improvement of the present invention is that the hydrogenation catalyst taken out of step (3) is sieved through an 18-mesh vibrating screen, and the hydrogenation catalyst is simultaneously purged from top to bottom by means of compressed air to remove broken particles and dust on its surface, thereby obtaining a regenerated hydrogenation catalyst with complete particles and reasonable particle distribution.

[0020] The beneficial effects of the present invention are:

[0021] 1. The present invention integrates charring regeneration and activity recovery into one, changes the immersion method into a spray method, and uses its own heat to achieve a drying effect. Compared with the distributed method, the energy consumption cost and solution cost are lower, and the regeneration time is shortened, achieving efficient regeneration and activity recovery.

[0022] 2. The present invention integrates compressed air cleaning and screening methods into one, which can achieve more efficient surface cleaning of the hydrogenation catalyst and improve the quality of the regeneration process and the final product quality.

[0023] 3. The present invention integrates acid treatment and char regeneration into one, and uses acid to treat the hydrogenation catalyst while performing low-temperature pretreatment, which can remove some pollutants and sediments on the catalyst surface, and also provides convenience for low-temperature pretreatment oil removal, so that the oil removal effect is better. At the same time, the drying effect after acid treatment is achieved by using its own temperature, which reduces additional drying energy consumption and reduces costs. DETAILED DESCRIPTION

[0024] The technical solution of the present invention is further described in detail below through specific embodiments:

[0025] Example 1

[0026] The deactivated hydrogenation catalyst in this example contains carbon (m%): 1.8%, and sulfur (m%): 6.6%.

[0027] The deactivated hydrogenation catalyst is subjected to an ex situ regeneration treatment, and the ex situ regeneration method comprises the following specific steps:

[0028] (1) Pretreatment: The deactivated hydrogenation catalyst was placed in an 18-mesh vibrating screen for screening, and the deactivated hydrogenation catalyst was simultaneously purged from top to bottom by means of compressed air blowing. The jet pressure of the compressed air was 0.45 MPa, and the carbon powder and impurities on the surface were removed to obtain a deactivated hydrogenation catalyst with a moderate particle size;

[0029] (2) Limited charring treatment: the deactivated hydrogenation catalyst with moderate particle size obtained in step (1) is spread on the conveying mesh belt of the regeneration mesh belt kiln and conveyed into the furnace, which is sequentially composed of three temperature sections: low-temperature preheating section - sulfur burning and charring section - cooling section, wherein the temperature of the low-temperature preheating section is set to 250°C, the residence time of the deactivated hydrogenation catalyst in the low-temperature preheating section is 3 hours, the temperature of the sulfur burning and charring section is set to 380°C, the residence time of the deactivated hydrogenation catalyst in the low-temperature preheating section is 3 hours, an inert gas is introduced into the cooling section as cooling gas, the residence time of the deactivated hydrogenation catalyst in the cooling section is 2 hours, and the deactivated hydrogenation catalyst is discharged from the furnace after being cooled to room temperature;

[0030] Among them, an acid spray system and a turning device are arranged in the low-temperature preheating section. When the deactivated hydrogenation catalyst is sent to the low-temperature preheating section, the acid spray system is started to spray the acid evenly on the surface of the deactivated hydrogenation catalyst. At the same time, the turning device is started to turn the deactivated hydrogenation catalyst on the transmission mesh belt so that the acid can be fully sprayed on the surface of the deactivated hydrogenation catalyst. The amount of acid per kg of deactivated hydrogenation catalyst is 10L and the spraying time is 5min. The deactivated hydrogenation catalyst is treated with acid to reduce the interaction between the metal components and carbon deposits in the catalyst and the carrier. At the same time, the temperature set in the low-temperature preheating section can achieve a drying effect, and there is no need to dry the deactivated hydrogenation catalyst after the acid treatment.

[0031] The acid solution is one or a mixture of hydrochloric acid, nitric acid, acetic acid, oxalic acid, phosphoric acid, citric acid, tartaric acid, and malic acid;

[0032] (3) Activation treatment: A regeneration liquid spray system and a turning device are provided in the cooling section of the regeneration mesh belt kiln. When the deactivated hydrogenation catalyst is cooled to 200°C in the cooling section, the regeneration liquid spray system is started to spray the regeneration liquid evenly on the surface of the deactivated hydrogenation catalyst. At the same time, the turning device is started to turn the deactivated hydrogenation catalyst on the conveying mesh belt so that the regeneration liquid can be fully sprayed on the surface of the deactivated hydrogenation catalyst. The spraying is stopped after the deactivated hydrogenation catalyst is cooled to 150°C, and the deactivated hydrogenation catalyst is dried by utilizing the residual heat to obtain an activated hydrogenation catalyst.

[0033] The regeneration liquid is an aqueous solution composed of nitrilotriacetic acid, diammonium hydrogen phosphate and deionized water.

[0034] The hydrogenation catalyst out of the furnace must also be sieved through an 18-mesh vibrating screen and simultaneously purged from top to bottom using compressed air to remove broken particles and dust on its surface to obtain a regenerated hydrogenation catalyst with complete particles and reasonable particle distribution.

[0035] After testing, the regenerated hydrogenation catalyst contained carbon (m%): 0.3%, sulfur (m%): 1.4%, pore volume (mL / g): 0.39, specific surface area (m 2 / g): 241, crushing strength (N / cm): 198, regeneration time 9h.

[0036] Example 2

[0037] The deactivated hydrogenation catalyst in this example contains carbon (m%): 1.26%, and sulfur (m%): 6.8%.

[0038] The deactivated hydrogenation catalyst of this example was treated using the ex situ regeneration method in Example 1.

[0039] After testing, the regenerated hydrogenation catalyst contained carbon (m%): 0.12%, sulfur (m%): 1.0%, pore volume (mL / g): 0.32, specific surface area (m 2 / g): 198, crushing strength (N / cm): 196, regeneration time 9.5h.

[0040] The above examples demonstrate that the ex situ regeneration method provided by the present invention has good hydrogenation catalyst regeneration ability and effect.

[0041] Comparative Example 1

[0042] The deactivated hydrogenation catalyst in Example 1 was treated using the method provided in Patent No. 201110027356.0, and the indicators of the treated hydrogenation catalyst and the treatment time during the treatment process were tested.

[0043] After testing, the regenerated hydrogenation catalyst after treatment by the above method contained carbon (m%): 0.41%, sulfur (m%): 1.6%, pore volume (mL / g): 0.3, specific surface area (m 2 / g): 200, crushing strength (N / cm): 190, regeneration time 24h.

[0044] The above comparative examples prove that the off-site regeneration method provided by the present invention has better regeneration effect and takes less time. Since the processes are concentrated in one, the energy consumption is bound to be much lower than the method given in comparative example 1.

[0045] Although the embodiments of the present invention have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limiting the present invention. Ordinary technicians in the field can change, modify, replace and modify the above embodiments within the scope of the present invention without departing from the principles and purpose of the present invention. Any simple modifications, equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention are still within the scope of the technical solution of the present invention.

Claims

1. A method for regenerating a hydrotreating catalyst ex situ, characterized in that: The method comprises the following steps: (1) Pretreatment: The deactivated hydrogenation catalyst is placed in a vibrating screen for screening, and the deactivated hydrogenation catalyst is simultaneously purged from top to bottom by means of compressed air to remove carbon powder and impurities on its surface to obtain a deactivated hydrogenation catalyst with a moderate particle size; (2) Limited charring treatment: the deactivated hydrogenation catalyst with moderate particle size obtained in step (1) is spread on the conveying mesh belt of the regeneration mesh belt kiln and conveyed into the furnace, which is sequentially composed of three temperature sections: low-temperature preheating section - sulfur burning and charring section - cooling section, wherein the temperature of the low-temperature preheating section is set to 250°C, the residence time of the deactivated hydrogenation catalyst in the low-temperature preheating section is 3 hours, the temperature of the sulfur burning and charring section is set to 380°C, the residence time of the deactivated hydrogenation catalyst in the low-temperature preheating section is 3 hours, an inert gas is introduced into the cooling section as cooling gas, the residence time of the deactivated hydrogenation catalyst in the cooling section is 2 hours, and the deactivated hydrogenation catalyst is discharged from the furnace after being cooled to room temperature; (3) Activation treatment: A regeneration liquid spray system and a turning device are provided in the cooling section of the regeneration mesh belt kiln. When the deactivated hydrogenation catalyst is cooled to 200°C in the cooling section, the regeneration liquid spray system is started to spray the regeneration liquid evenly on the surface of the deactivated hydrogenation catalyst. At the same time, the turning device is started to turn the deactivated hydrogenation catalyst on the transmission mesh belt so that the regeneration liquid can be fully sprayed on the surface of the deactivated hydrogenation catalyst. The spraying is stopped after the deactivated hydrogenation catalyst is cooled to 150°C, and the residual heat is used to dry the deactivated hydrogenation catalyst to obtain an activated hydrogenation catalyst.

2. The method for regenerating a hydrotreating catalyst according to claim 1, characterized in that: The jet pressure of the compressed air in step (1) is 0.45 MPa, and the mesh number of the vibrating screen is 18 meshes.

3. The method for regenerating a hydrotreating catalyst according to claim 1, characterized in that: The low-temperature preheating section of the regeneration mesh belt kiln in step (2) is provided with an acid liquid spray system and a turning device. When the deactivated hydrogenation catalyst is delivered to the low-temperature preheating section, the acid liquid spray system is started to spray the acid liquid evenly on the surface of the deactivated hydrogenation catalyst. At the same time, the turning device is started to turn the deactivated hydrogenation catalyst on the transmission mesh belt so that the acid liquid can be fully sprayed on the surface of the deactivated hydrogenation catalyst. The amount of acid liquid used per kg of deactivated hydrogenation catalyst is 10 L and the spraying time is 5 min.

4. The method for regenerating a hydrotreating catalyst according to claim 3, characterized in that: The acid solution is one of hydrochloric acid, nitric acid, acetic acid, oxalic acid, phosphoric acid, citric acid, tartaric acid and malic acid, or a mixture of several of them.

5. The method for regenerating a hydrotreating catalyst according to claim 1, characterized in that: The regeneration liquid in step (3) is an aqueous solution composed of nitrilotriacetic acid, diammonium hydrogen phosphate and deionized water.

6. The method for regenerating a hydrotreating catalyst according to claim 1, characterized in that: The hydrogenation catalyst taken out of the furnace in step (3) is sieved through an 18-mesh vibrating screen, and the hydrogenation catalyst is simultaneously purged from top to bottom by means of compressed air to remove the broken particles and dust on the surface thereof, thereby obtaining a regenerated hydrogenation catalyst with complete particles and reasonable particle distribution.