Regeneration method suitable for deactivation of coal tar hydrogenation catalyst caused by Ca element

Abstract

The invention relates to the technical field of catalyst regeneration, in particular to a regeneration method suitable for deactivation of a coal tar hydrogenation catalyst caused by Ca. The method comprises the following steps: extracting a Ca element inactivated coal tar hydrogenation catalyst by using an organic solvent, drying, mixing and stirring the obtained intermediate catalyst and a citric acid solution, adding an active metal salt, carrying out a hydrothermal heating reaction, filtering the reaction product, and drying to obtain the Ca element inactivated coal tar hydrogenation catalyst. And washing the obtained solid product with water and ethanol, drying, and calcining the obtained dried catalyst to obtain the regenerated coal tar hydrogenation catalyst. According to the method, Ca on the surface of the catalyst is removed through low-temperature hydrothermal treatment, active metal is loaded again through high-temperature hydrothermal treatment, carbon on the surface of the catalyst is removed through high-temperature calcination, the content of Ca and C on the surface in the obtained regenerated coal tar hydrogenation catalyst is reduced to 100 PPM, and the content of the active metal can be recovered to be before reaction.

Description

Technical Field

[0001] The invention relates to the technical field of catalyst regeneration, in particular to a regeneration method suitable for a coal tar hydrogenation catalyst deactivated by Ca element. Background Art

[0002] Affected by the high alkaline earth metal content of coal in Xinjiang, medium and low temperature coal tar shows obvious high calcium characteristics, especially the coal tar in Zhundong and Hami. Medium and low temperature coal tar in Xinjiang mainly comes from coal pyrolysis and gasification processes. The Ca content of gasification coal tar is low (120μg / g to 300μg / g), and the Ca content of pyrolysis coal tar is high (300μg / g to 600μg / g). The Ca element in medium and low temperature coal tar exists mainly in three forms, 10% to 20% of Ca exists in the form of water-soluble compounds, 30% of Ca exists in the form of solid impurities, and the rest exists in the form of oil-soluble Ca compounds.

[0003] At present, there is no proprietary technology for hydrogenation demetallization, and the hydrodemetallization technology of the petrochemical industry is mainly used. The demetallization catalysts in the crude oil processing industry are mainly used to remove metals such as V, Fe, and Mo, and there is relatively little research on the Ca element. Metals such as V, Fe, and Mo can be distributed on the surface and inside of the catalyst, while Ca is deposited on the surface of the catalyst to form a high-Ca thin layer, which inhibits the catalytic reaction.

[0004] Therefore, the deactivation mechanism and regeneration method of coal tar hydrogenation catalysts caused by Ca element are different from those of other catalysts. The regeneration method of existing catalysts is not suitable for coal tar hydrogenation catalysts deactivated by Ca element. It is necessary to develop a regeneration method suitable for coal tar hydrogenation catalysts deactivated by Ca element. Summary of the invention

[0005] The present invention provides a regeneration method suitable for coal tar hydrogenation catalyst deactivated by Ca element, which overcomes the shortcomings of the above-mentioned prior art and can effectively solve the problem of coal tar hydrogenation catalyst deactivation caused by the presence of Ca element in the existing catalyst regeneration method.

[0006] The technical solution of the present invention is achieved by the following measures: A regeneration method suitable for coal tar hydrogenation catalyst deactivated by Ca element is carried out according to the following steps: The first step is to use an organic solvent to extract the coal tar hydrogenation catalyst deactivated by the Ca element and then dry it to obtain an intermediate catalyst; The second step is to mix and stir the intermediate catalyst with a required amount of citric acid solution, add a required amount of active metal salt, and then perform a hydrothermal temperature increase reaction to obtain a reaction product; The third step is to filter the reaction product, wash the solid product with water and ethanol, and then dry it to obtain a dry catalyst; The fourth step is to calcine the dried catalyst to obtain a regenerated coal tar hydrogenation catalyst.

[0007] The following are further optimizations and / or improvements to the above technical solutions: In the first step, the organic solvent is one or more of toluene, n-heptane, tetrahydrofuran and ethanol, and the mass ratio of the organic solvent to the coal tar hydrogenation catalyst deactivated by the Ca element is 1:1 to 1:5.

[0008] In the first step, the organic solvent is a mixture of toluene and ethanol or tetrahydrofuran, and the mass ratio of the organic solvent to the coal tar hydrogenation catalyst deactivated by the Ca element is 1:2 to 1:3.

[0009] In the first step, the extraction temperature is 80 to 150°C, the extraction time is 4 to 12 hours, the drying temperature is 100 to 110°C, and the drying time is 3.5 to 4.5 hours; or / and, in the second step, the stirring rate is 200 to 600 rpm, the stirring time is 20 to 40 minutes, and the stirring temperature is 40 to 80°C.

[0010] In the first step, the extraction temperature is 100°C to 120°C, the extraction time is 5h to 10h, the drying temperature is 105°C, and the drying time is 4h; or / and, in the second step, the stirring rate is 300 rmp to 400 rmp, the stirring time is 30min, and the stirring temperature is 60°C to 70°C.

[0011] In the above second step, the active metal salt is one or more of sulfate, nitrate and molybdate, the added mass of the active metal salt is 0.005%wt to 0.1%wt of the intermediate catalyst mass, and the concentration of the citric acid solution is 0.01%wt to 1%wt.

[0012] In the above second step, the mass of the active metal salt added is 0.015%wt to 0.05%wt of the mass of the intermediate catalyst, and the concentration of the citric acid solution is 0.05%wt to 0.1%wt.

[0013] In the above-mentioned second step, the hydrothermal reaction mode is a second-order hydrothermal reaction, wherein the first-order hydrothermal reaction temperature is 100°C to 160°C, the second-order hydrothermal reaction temperature is 160°C to 300°C, the first-order hydrothermal reaction time is 4h to 24h, and the second-order hydrothermal reaction time is 2h to 12h.

[0014] In the above-mentioned second step, the hydrothermal heating reaction mode is a second-order heating reaction, wherein the first-order hydrothermal reaction temperature is 120°C to 140°C, the second-order hydrothermal reaction temperature is 180°C to 220°C, the first-order hydrothermal reaction time is 4h to 12h, and the second-order hydrothermal reaction time is 4h to 8h.

[0015] In the fourth step, the calcination temperature is 440° C. to 500° C., and the calcination time is 3.5 h to 4.5 h.

[0016] The present invention removes Ca elements on the surface of the catalyst through low-temperature hydrothermal treatment, reloads active metals through high-temperature hydrothermal treatment, and removes carbon deposited on the surface of the catalyst through high-temperature calcination. The surface Ca and C contents of the obtained regenerated coal tar hydrogenation catalyst are reduced to 100 PPM, and the active metal content can be restored to the content before the reaction. DETAILED DESCRIPTION

[0017] 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.

[0018] The present invention will be further described below in conjunction with embodiments: Example 1: The regeneration method for coal tar hydrogenation catalyst deactivated by Ca element is carried out according to the following steps: The first step is to use an organic solvent to extract the coal tar hydrogenation catalyst deactivated by the Ca element and then dry it to obtain an intermediate catalyst; The second step is to mix and stir the intermediate catalyst with a required amount of citric acid solution, add a required amount of active metal salt, and then perform a hydrothermal temperature increase reaction to obtain a reaction product; The third step is to filter the reaction product, wash the solid product with water and ethanol, and then dry it to obtain a dry catalyst; The fourth step is to calcine the dried catalyst to obtain a regenerated coal tar hydrogenation catalyst.

[0019] Example 2: As an optimization of the above example, in the first step, the organic solvent is one or more of toluene, n-heptane, tetrahydrofuran, and ethanol, and the mass ratio of the organic solvent to the coal tar hydrogenation catalyst deactivated by Ca element is 1:1 to 1:5.

[0020] Example 3: As an optimization of the above example, in the first step, the organic solvent is a mixture of toluene and ethanol or tetrahydrofuran, and the mass ratio of the organic solvent to the coal tar hydrogenation catalyst deactivated by Ca element is 1:2 to 1:3.

[0021] Example 4: As an optimization of the above example, in the first step, the extraction treatment temperature is 80°C to 150°C, the extraction treatment time is 4h to 12h, the drying treatment temperature is 100°C to 110°C, and the drying treatment time is 3.5h to 4.5h.

[0022] Example 5: As an optimization of the above example, in the first step, the temperature of the extraction treatment is 100°C to 120°C, the time of the extraction treatment is 5h to 10h, the temperature of the drying treatment is 105°C, and the time of the drying treatment is 4h.

[0023] Example 6: As an optimization of the above example, in the second step, the stirring rate is 200 rpm to 600 rpm, the stirring time is 20 min to 40 min, and the stirring temperature is 40°C to 80°C.

[0024] Example 7: As an optimization of the above example, in the second step, the stirring rate is 300 to 400 rpm, the stirring time is 30 min, and the stirring temperature is 60° C. to 70° C.

[0025] Example 8: As an optimization of the above example, in the second step, the active metal salt is one or more of sulfate, nitrate and molybdate, the added mass of the active metal salt is 0.005%wt to 0.1%wt of the intermediate catalyst mass, and the concentration of the citric acid solution is 0.01%wt to 1%wt.

[0026] Example 9: As an optimization of the above example, in the second step, the mass of the active metal salt added is 0.015%wt to 0.05%wt of the mass of the intermediate catalyst, and the concentration of the citric acid solution is 0.05%wt to 0.1%wt.

[0027] Example 10: As an optimization of the above example, in the second step, the hydrothermal reaction mode is a second-order hydrothermal reaction, wherein the first-order hydrothermal reaction temperature is 100°C to 160°C, the second-order hydrothermal reaction temperature is 160°C to 300°C, the first-order hydrothermal reaction time is 4h to 24h, and the second-order hydrothermal reaction time is 2h to 12h.

[0028] Example 11: As an optimization of the above example, in the second step, the hydrothermal temperature rising reaction mode is a second-order temperature rising reaction, wherein the first-order hydrothermal reaction temperature is 120°C to 140°C, the second-order hydrothermal reaction temperature is 180°C to 220°C, the first-order hydrothermal reaction time is 4h to 12h, and the second-order hydrothermal reaction time is 4h to 8h.

[0029] Example 12: As an optimization of the above example, in the fourth step, the calcination temperature is 440°C to 500°C, and the calcination time is 3.5h to 4.5h.

[0030] Example 13: The regeneration method for coal tar hydrogenation catalyst deactivated by Ca element is carried out according to the following steps: In the first step, 10 g of a (Mo-based) coal tar hydrogenation catalyst deactivated by Ca element was weighed, 30 g of tetrahydrofuran was added, and the mixture was extracted at 100° C. for 8 hours, filtered, and dried at 105° C. for 4 hours to obtain an intermediate catalyst; The second step is to weigh 10g of the intermediate catalyst and 0.075g of citric acid and dissolve them in 100ml of distilled water and stir for 30min. Then, 1.7302g of ammonium molybdate is added under stirring (stirring rate is 400 rmp, stirring time is 30min, stirring temperature is 60℃), and the obtained solution is transferred to a hydrothermal kettle, and reacted at 120℃ for 4h and 200℃ for 4h to obtain a reaction product. The third step is to filter the reaction product, wash the obtained black solid product with water and ethanol three times, and then dry it for 4 hours to obtain a dry catalyst; In the fourth step, the dried catalyst was placed in a muffle furnace and calcined at 500° C. for 4 h to obtain a regenerated (Mo-based) coal tar hydrogenation catalyst.

[0031] The regenerated (Mo-based) coal tar hydrogenation catalyst obtained in Example 13 was tested, and the surface Ca and C element contents were reduced to 100 PPM, and the active metal ammonium molybdate content was restored to the content before the reaction (i.e., 1.7302 g).

[0032] In summary, the present invention removes the Ca element on the catalyst surface by low-temperature hydrothermal treatment, reloads the active metal by high-temperature hydrothermal treatment, and removes the carbon on the catalyst surface by high-temperature calcination. The surface Ca and C contents in the obtained regenerated coal tar hydrogenation catalyst are reduced to 100 PPM, and the active metal content can be restored to the level before the reaction.

[0033] 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 regeneration method for coal tar hydrogenation catalyst deactivated by Ca element, Features Follow the steps below: The first step is to use an organic solvent to extract the coal tar hydrogenation catalyst deactivated by the Ca element and then dry it to obtain an intermediate catalyst; The second step is to mix and stir the intermediate catalyst with a required amount of citric acid solution, add a required amount of active metal salt, and then perform a hydrothermal temperature increase reaction to obtain a reaction product; The third step is to filter the reaction product, wash the solid product with water and ethanol, and then dry it to obtain a dry catalyst; The fourth step is to calcine the dried catalyst to obtain a regenerated coal tar hydrogenation catalyst.

2. The regeneration method for coal tar hydrogenation catalyst deactivated by Ca element according to claim 1, Features In the first step, the organic solvent is one or more of toluene, n-heptane, tetrahydrofuran, and ethanol, and the mass ratio of the organic solvent to the coal tar hydrogenation catalyst deactivated by the Ca element is 1:1 to 1:

5.

3. The regeneration method for coal tar hydrogenation catalyst deactivated by Ca element according to claim 2, Features In the first step, the organic solvent is a mixture of toluene and ethanol or tetrahydrofuran, and the mass ratio of the organic solvent to the coal tar hydrogenation catalyst deactivated by the Ca element is 1:2 to 1:

3.

4. The regeneration method for coal tar hydrogenation catalyst deactivated by Ca element according to any one of claims 1 to 3, Features In the first step, the extraction treatment temperature is 80°C to 150°C, the extraction treatment time is 4h to 12h, the drying treatment temperature is 100°C to 110°C, and the drying treatment time is 3.5h to 4.5h; or / and, in the second step, the stirring rate is 200 rmp to 600 rmp, the stirring time is 20min to 40min, and the stirring temperature is 40°C to 80°C.

5. The regeneration method for coal tar hydrogenation catalyst deactivated by Ca element according to claim 4, Features In the first step, the extraction temperature is 100°C to 120°C, the extraction time is 5h to 10h, the drying temperature is 105°C, and the drying time is 4h; or / and, in the second step, the stirring rate is 300 rmp to 400 rmp, the stirring time is 30min, and the stirring temperature is 60°C to 70°C.

6. The regeneration method for coal tar hydrogenation catalyst deactivated by Ca element according to any one of claims 1 to 5, Features In the second step, the active metal salt is one or more of sulfate, nitrate and molybdate, the added mass of the active metal salt is 0.005%wt to 0.1%wt of the intermediate catalyst mass, and the concentration of the citric acid solution is 0.01%wt to 1%wt.

7. The regeneration method for coal tar hydrogenation catalyst deactivated by Ca element according to claim 6, Features In the second step, the mass of the active metal salt added is 0.015%wt to 0.05%wt of the mass of the intermediate catalyst, and the concentration of the citric acid solution is 0.05%wt to 0.1%wt.

8. The regeneration method for coal tar hydrogenation catalyst deactivated by Ca element according to any one of claims 1 to 7, Features In the second step, the hydrothermal reaction mode is a second-order hydrothermal reaction, wherein the first-order hydrothermal reaction temperature is 100°C to 160°C, the second-order hydrothermal reaction temperature is 160°C to 300°C, the first-order hydrothermal reaction time is 4h to 24h, and the second-order hydrothermal reaction time is 2h to 12h.

9. The regeneration method for coal tar hydrogenation catalyst deactivated by Ca element according to claim 8, Features In the second step, the hydrothermal reaction mode is a second-order temperature rising reaction, wherein the first-order hydrothermal reaction temperature is 120°C to 140°C, the second-order hydrothermal reaction temperature is 180°C to 220°C, the first-order hydrothermal reaction time is 4h to 12h, and the second-order hydrothermal reaction time is 4h to 8h.

10. The regeneration method for coal tar hydrogenation catalyst deactivated by Ca element according to any one of claims 1 to 9, Features In the fourth step, the calcination temperature is 440° C. to 500° C., and the calcination time is 3.5 h to 4.5 h.