CN109926103B

CN109926103B - Regeneration method of deactivated catalyst

Info

Publication number: CN109926103B
Application number: CN201711353782.7A
Authority: CN
Inventors: 徐黎明; 高玉兰; 葛海龙; 孟兆会; 佟佳
Original assignee: China Petroleum and Chemical Corp; Sinopec Dalian Research Institute of Petroleum and Petrochemicals
Current assignee: Sinopec Dalian Petrochemical Research Institute Co ltd; China Petroleum and Chemical Corp
Priority date: 2017-12-15
Filing date: 2017-12-15
Publication date: 2021-10-08
Anticipated expiration: 2037-12-15
Also published as: CN109926103A

Abstract

The invention provides a regeneration method of a deactivated catalyst, which comprises the following steps: (1) contacting a hydrogenation catalyst to be regenerated with oxygen-containing gas for charcoal burning treatment to obtain a catalyst A; (2) contacting the catalyst A with an organic compound solution, and carrying out heat treatment to obtain a catalyst B; (3) and (3) introducing organic sulfide and hydrazine hydrate into the catalyst B, and then carrying out heat treatment to obtain a regenerated catalyst. The regeneration method can improve the activity of the regenerated catalyst.

Description

Regeneration method of deactivated catalyst

Technical Field

The invention relates to a method for treating a catalyst, in particular to a method for regenerating a deactivated catalyst.

Background

Hydrotreating is a very important process for converting crude oil into high-value products, and the core of hydrotreating is a hydrotreating catalyst. The activity of the catalyst is provided by the sulfided state of the metal. The catalyst is generally classified into coking inactivation (causing catalyst pore blockage), poisoning inactivation (causing catalyst acid center poisoning), sintering inactivation (causing catalyst crystal phase change), and the like. The main causes of deactivation of industrial hydrogenation catalysts are coke formation and metal plugging, migration or aggregation of active metal components, changes in phase composition, reduction in the number of active centers, sintering of the support, collapse and collapse of the zeolite structure, etc. The activity of the deactivated catalyst caused by carbon deposition can be recovered by a regeneration method, while the deactivated catalyst caused by metal deposition pollution can not be regenerated to recover the activity and only can be discarded. So said regeneration is generally referred to as soot regeneration.

The essence of the ex-situ regeneration patent technology is that the carbon deposit on the surface is removed by contacting the deactivated catalyst with oxygen-containing gas, namely, the catalyst is regenerated by burning the carbon. Compared with the fresh catalyst, the regenerated catalyst has a certain reduction in pore volume and specific surface area, and the reduction range of activity is larger.

CN1782030A discloses a method for regenerating a hydrogenation catalyst, which comprises the following steps: 1) mixing the granular alkaline substance with the inactivated hydrogenation catalyst, wherein the weight mixing ratio of the granular alkaline substance to the inactivated hydrogenation catalyst is 5: 95-50: 50; 2) contacting a mixture of a particulate basic material and a deactivated hydrogenation catalyst with an oxygen-containing gas under oxidative regeneration reaction conditions; 3) separating and regenerating the hydrogenation catalyst. The regenerated catalyst obtained by the method has high activity and can ensure that SO in the regenerated exhaust tail gas can be simultaneously discharged₂The content of (A) is obviously reduced.

Disclosure of Invention

To increase the activity and stability of hydrogenation catalysts, they are usually presulfided before use to convert the hydrogenation metal component to sulfide. Therefore, in the catalyst regeneration process, the oxidation reaction of the sulfide is accompanied with the scorching. The metal in the catalyst exists in oxidation state mostly due to the high-temperature carbon burning step in the regeneration outside the reactor. However, the inventors found that the sulfide in the catalyst cannot be completely removed by the conventional high-temperature regeneration charcoal burning treatment, and that in the process of burning charcoal and burning sulfur, a part of sulfur oxides in the metal sulfide remains on the carrier to form sulfate or sulfite, which poisons the catalyst and affects the activity of the catalyst after regeneration. And the high-temperature carbon burning easily causes the aggregation of metal, and the utilization rate of active metal is low. Greatly influences the service performance of the regenerated catalyst and also influences the reaction result.

Aiming at the defects of the prior art, the invention provides a regeneration method of a deactivated catalyst, which can improve the utilization rate of active metal of the regenerated catalyst and improve the activity of the regenerated catalyst compared with the prior regeneration method.

The invention provides a regeneration method of a deactivated catalyst, which comprises the following steps:

(1) contacting a hydrogenation catalyst to be regenerated with oxygen-containing gas for charcoal burning treatment to obtain a catalyst A;

(2) contacting the catalyst A with an organic compound solution, and carrying out heat treatment to obtain a catalyst B;

(3) and (3) introducing organic sulfide and hydrazine hydrate into the catalyst B, and then carrying out heat treatment to obtain a regenerated catalyst.

In the regeneration method, the charcoal firing treatment in the step (1) comprises two steps, wherein the roasting temperature in the first step is 150-220 ℃, and preferably 180-200 ℃; the roasting time is 3-15 hours; the roasting temperature of the second step is 300-400 ℃, preferably 320-350 ℃, and the roasting time is 3-15 hours, wherein the roasting temperature of the second step is 120-180 ℃ higher than that of the first step. Wherein, the charcoal burning treatment device can adopt one or more of a tunnel kiln, a rotary kiln, a moving bed, a box type furnace and a tubular furnace.

In the regeneration method, the oxygen-containing gas in the step (1) can be oxygen, air, a mixed gas of oxygen and an inert medium, or a mixed gas of air and an inert medium, the oxygen content of the mixed gas is 0.5-40% by volume, and the inert medium can be one or more selected from nitrogen, argon, helium, carbon dioxide, a flue gas and water vapor. In practice, the selection and matching of the corresponding operating parameters will be known to those skilled in the art, depending on the carbon, sulfur content or physicochemical properties of the hydrogenation catalyst to be regenerated, such as the amount of oxygen-containing gas introduced and the oxygen content of the oxygen-containing gas.

In the regeneration method, the catalyst A after the control of the carbon burning treatment in the step (1) contains sulfur and carbon, the content of the carbon does not exceed 2.5wt% of the catalyst A, and is preferably 1.0-2.0 wt%, and the content of the sulfur accounts for 0.2-3.0 wt% of the catalyst A, is preferably 0.5-2.5 wt%, and is further preferably 1.0-2.0 wt%.

In the regeneration method of the invention, the organic compound in the step (2) is tetrakis (hydroxymethyl) phosphonium salt and homologues thereof, such as tetrakis (hydroxymethyl) phosphonium chloride and homologues thereof and/or tetrakis (hydroxymethyl) phosphonium sulfate and homologues thereof, the substituted hydrocarbons are the same or different and can be saturated or unsaturated, straight-chain or branched-chain, cycloalkyl or aryl, and the number of carbon atoms of the hydrocarbons can be 1-10. Specifically, the phosphorus chloride may be one or more of tetrahydroxyethyl phosphorus chloride, tetrahydroxylaniline methyl phosphorus chloride, tetrahydroxybenzyl phosphorus chloride, tetrahydroxypropyl phosphorus chloride, tetrahydroxyvinyl phosphorus chloride, tetrahydroxyethyl methyl phosphorus sulfate, tetrahydroxylaniline methyl phosphorus sulfate, tetrahydroxybenzyl phosphorus sulfate, tetrahydroxypropyl phosphorus sulfate, and tetrahydroxyvinyl phosphorus sulfate.

In the regeneration method of the invention, the amount of the organic compound in the step (2) is 2-50% of the weight of the catalyst A, and is preferably 8-40%.

In the regeneration method, the heat treatment temperature in the step (2) is 100-200 ℃, and preferably 120-180 ℃; the heat treatment time is 2-10 hours.

In the regeneration method of the invention, the organic sulfide is a vulcanizing agent conventionally used in the field, and generally can be one or more of sulfur-containing organic substances. Such as one or more of mercaptan, carbon disulfide, dimethyl disulfide (DMDS), dimethyl sulfide, and polysulfide selected from the group consisting of those of the general formula R-S_n-one or more organic polysulphides of R ', n being 2 to 10, R and R ' being identical or different and being saturated or unsaturated, linear or branched, cycloalkyl or aromatic, and the number of carbon atoms of R and R ' being 1 to 10.

In the regeneration method, the dosage of the organic sulfide is 85-150%, preferably 95-120% of the theoretical sulfur demand of the metal component of the hydrogenation catalyst.

In the regeneration method, the usage amount of the hydrazine hydrate is 20 to 160 percent of the sum of the sulfur content of the catalyst A and the sulfur content of the organic sulfide.

In the regeneration method of the present invention, the method and conditions for contacting the catalyst a obtained after the coke-burning treatment with the solution containing the organic compound and the organic sulfide are not particularly limited. For example, the catalyst may be sprayed or the catalyst may be directly impregnated in the solution after the calcination.

In the regeneration method, the heat treatment temperature in the step (3) is 60-160 ℃, and preferably 80-130 ℃; the heat treatment time is 2-10 hours.

In the regeneration method, the hydrogenation catalyst to be regenerated can be a catalyst used in various processes such as hydrodesulfurization, hydrodenitrogenation, hydrodemetallization, hydrofining, hydrocracking, hydrodearomatization, selective hydrocracking, catalytic reforming and the like in chemical production and petroleum refining and a desulfurization catalyst in the synthetic ammonia industry. The active metal component of the catalyst is one or more of W, Mo, Ni and Co, and generally refractory inorganic oxides are used as carriers, such as alumina, silicon oxide, amorphous silicon-aluminum, titanium oxide, molecular sieves, composite oxides of various elements or mixed oxygen carriers and the like. The hydrogenation catalyst to be regenerated can be subjected to oil removal operation before the charcoal burning treatment, can be specifically determined according to the application requirements according to the general knowledge in the field, and can be subjected to flash evaporation or solvent oil removal.

In the regeneration method, on the premise of ensuring that the pore channel of the catalyst is recovered in the process of burning the carbon, the depth of burning the sulfur is controlled by adopting lower temperature as far as possible. The sulfur on the carrier is partially oxidized and discharged, and a part of the sulfur can be in a reduced state. Then introducing an organic compound and hydrazine hydrate, and leading the part of sulfur and metal in the process of burning the carbon of the deactivated catalyst to be unbound through the introduction of the organic compound. Then after the introduction of the organic sulfide, the organic sulfide and the residual organic compound form an intermediate which is uniformly loaded on the surface and in the pore channels of the catalyst. The intermediate formed at low temperature during startup vulcanization of the regenerated catalyst fixes sulfide, so that high-temperature air tightness of the device is smoothly performed, after the temperature rises to a certain height, the intermediate is decomplexed, and the sulfide reacts with hydrogen and metal to perform vulcanization of the catalyst, so that the vulcanization quality of the catalyst can be ensured, and the problem of air tightness of the device can be solved. The organic compound is matched with various organic sulfides, so that exothermic peaks of a vulcanization reaction can be dispersed, and temperature runaway of a bed layer can be avoided. The method can also reduce the use amount of organic sulfide, and has good economical efficiency.

Detailed Description

The technical features of the present invention are further described below by way of examples, but these examples are not intended to limit the present invention, and wt% referred to is mass fraction.

Example 1

Taking an inactivated hydrotreating catalyst with carbon deposition of 6.5 percent, wherein the active metal components of the catalyst are Mo and Ni, and carrying out carbon burning regeneration treatment in an oxygen-containing atmosphere. Heating to 200 ℃ at a heating rate of 3 ℃/min, keeping the temperature for 10 hours, continuously heating to 330 ℃ and keeping the temperature for 8 hours to obtain a sample with the carbon content of 1.5 percent and the sulfur content of 1.8 percent. The obtained sample was named C-1.

Taking an inactivated hydrotreating catalyst with carbon deposition of 8.2 percent, wherein the active metal components of the catalyst are Mo, Ni and Co, and carrying out carbon burning regeneration treatment under different conditions in an oxygen-containing atmosphere. Heating to 200 ℃ at a heating rate of 3 ℃/min, keeping the temperature for 10 hours, continuously heating to 320 ℃, keeping the temperature for 10 hours, and obtaining a sample with the carbon content of 1.7 percent and the sulfur content of 2.2 percent. The obtained sample was named C-2.

Example 2

61g of tetrakis (hydroxymethyl) phosphonium sulfate aqueous solution (the solution concentration is 75 wt%) is taken, catalyst C-1 is sprayed, after aging for 3 hours, the mixture is treated at low temperature of 100 ℃ for 3 hours, and after a mixed solution of DMDS14g and hydrazine hydrate 9ml is sprayed, the mixture is heat treated at low temperature of 100 ℃ for 3 hours. Thus obtaining the needed catalyst C-3.

Example 3

55g of tetrahydroxyethyl phosphorus sulfate is taken, diluted into 70ml of solution by water, the catalyst C-2 is sprayed by the solution, after aging for 3 hours, the solution is thermally treated at the low temperature of 80 ℃ for 3 hours, and after 12g of carbon disulfide and 9ml of hydrazine hydrate solution are sprayed, the solution is thermally treated at the low temperature of 100 ℃ for 3 hours. Thus obtaining the needed catalyst C-4.

Example 4

The same procedures used in example 2 were repeated except for using 22g of tetrakis (hydroxymethyl) phosphonium chloride to obtain the desired catalyst C-5.

Example 5

25g of tetrahydroxyvinylphosphorus chloride was taken, and the remainder was the same as in example 3, whereby the desired catalyst C-6 was obtained.

Comparative example 1

In comparison with example 1, 61g of an aqueous solution of tetrakis (hydroxymethyl) phosphonium sulfate (solution concentration: 75 wt%) was taken without using hydrazine hydrate, and the catalyst C-1 was sprayed, aged for 3 hours, then treated at a low temperature of 100 ℃ for 3 hours, and the DMDS14g solution was sprayed, and then heat-treated at a low temperature of 100 ℃ for 3 hours. Thus obtaining the required catalyst C-7.

Comparative example 2

Taking an inactivated hydrotreating catalyst with carbon deposition of 6.5 percent, wherein the active metal components of the catalyst are Mo and Ni, and carrying out carbon burning regeneration treatment in an oxygen-containing atmosphere. Heating to 200 ℃ at a heating rate of 3 ℃/min, keeping the temperature for 10 hours, continuously heating to 450 ℃, keeping the temperature for 8 hours, and obtaining a sample with the carbon content of 0.8 percent and the sulfur content of 0.2 percent. The obtained sample was named D-1. Sulfidation was then carried out as in example 1 to give the desired catalyst C-8.

Evaluation of the activity of the hydroprocessing catalyst of the invention:

test example 1 catalysts of examples and comparative examples were subjected to activity evaluation

The catalysts of examples and comparative examples were used for activity evaluation, and the evaluation was performed on a 200mL fixed bed hydrotreater. After the device is airtight, introducing hydrogen, directly heating to 200 ℃ at the speed of 20 ℃/h, keeping the temperature for 3h, and then introducing aviation kerosene with the density of 0.798g/cm³The distillation range is 161-276 ℃. The temperature is continuously increased to the reaction temperature of 320 ℃, and then the vulcanization is finished. Then raw oil is added, the temperature is continuously raised to 350 ℃, and the temperature is kept constant for 8 hours, and then sampling analysis is carried out. The tail gas was sampled and analyzed, and the contents of hydrogen sulfide and sulfide are shown in tables 1 and 2. The raw oil for evaluation is normal-third-line raw oil, and the process conditions are as follows: the pressure is 6.0MPa, the space velocity is 2.0, the temperature is 350 ℃, and the hydrogen-oil ratio is 1000. The evaluation results are shown in Table 3.

Test example 2 evaluation of Activity of catalyst after burning charcoal

The activity of the calcined catalysts C-1 and C-2 used in the experiments was evaluated and the evaluation was carried out on a 200mL hydrotreater. The sulfur oil in the catalyst vulcanization process is a mixture of aviation kerosene and carbon disulfide, and the density of the sulfur oil is 0.798g/cm³Sulfur content of 20000 mug/g, nitrogen content of 1.0 mug/g, distillation rangeIs 161-276 ℃. 100mL of oxidation type catalyst is loaded into a hydrogenation reactor, hydrogen is connected, the pressure is kept at 3.5MPa, the temperature is increased to 150 ℃ at the temperature rising speed of 20 ℃/h, the vulcanized oil is started to be fed, the temperature is kept for 3 hours, the temperature is increased to 230 ℃ at the temperature rising speed of 20 ℃/h, the temperature is kept for 8 hours, the temperature is increased to 320 ℃ and the temperature is kept for 8 hours, and then the vulcanization is finished. Then raw oil is added, the temperature is raised to 350 ℃, and the temperature is kept constant for 8 hours, and then sampling analysis is carried out. The stock oil and process conditions were the same as in test example 1. The evaluation results are shown in Table 3.

TABLE 1 evaluation conditions of catalysts

TABLE 2 evaluation results of catalysts

TABLE 3 analysis results of sulfides in exhaust gas

As can be seen from Table 3, the organic sulfide is directly supported on the catalyst, and the sulfide overflows from the catalyst pore channels at a low temperature of 110 ℃, whereas the high-pressure airtightness of the device is generally 150 ℃, which affects the airtightness of the device. The organic compound organic sulfide in the catalyst is adsorbed and complexed and is uniformly loaded on the surface and in pore channels of the catalyst, a complex formed by the organic compound and the organic sulfide at the low temperature of less than 200 ℃ is not decomposed when the catalyst is vulcanized, the sulfide is fixed, the high-temperature air tightness of the device is smoothly carried out, the organic compound and the sulfide are decomplexed after the temperature is raised to 200 ℃, and the sulfide reacts with hydrogen and metal to carry out the vulcanization of the catalyst, so that the vulcanization quality of the catalyst can be ensured, and the problem of air tightness of the device can be solved. As can be seen from table 2, the catalyst prepared by the present invention has improved metal utilization ratio and further improved hydrogenation activity compared to the catalyst prepared by the conventional regeneration method, and is economical.

Claims

1. A method for regenerating a deactivated catalyst, said method comprising the steps of:

(1) contacting a hydrogenation catalyst to be regenerated with oxygen-containing gas to carry out charcoal burning treatment to obtain a catalyst A, wherein the charcoal burning treatment comprises two steps, the roasting temperature of the first step is 150-220 ℃, and the roasting temperature of the second step is 300-400 ℃;

(2) contacting the catalyst A with an organic compound solution, and carrying out heat treatment to obtain a catalyst B, wherein the organic compound is tetrakis hydroxymethyl phosphonium chloride and homologues thereof and/or tetrakis hydroxymethyl phosphonium sulfate and homologues thereof;

2. The regeneration method according to claim 1, wherein: the charcoal burning treatment in the step (1) comprises two steps, wherein the first step roasting temperature is 180-200 ℃; the roasting time is 3-15 hours; the roasting temperature of the second step is 320-350 ℃, and the roasting time is 3-15 hours.

3. The regeneration method according to claim 2, wherein: the second-step roasting temperature is 120-180 ℃ higher than the first-step roasting temperature.

4. The regeneration method according to claim 1, wherein: the oxygen-containing gas in the step (1) is oxygen, air, a mixed gas of oxygen and an inert medium, or a mixed gas of air and an inert medium.

5. The regeneration method according to claim 4, wherein: the oxygen content of the mixed gas is 0.5 to 40 vol%.

6. The regeneration method according to claim 4, wherein: the inert medium is selected from one or more of nitrogen, argon, helium, carbon dioxide, flue gas and water vapor.

7. The regeneration method according to claim 1, wherein: the catalyst A after the regeneration is controlled by the charcoal burning treatment in the step (1) contains sulfur and charcoal, the content of the charcoal is not more than 2.5wt% of the catalyst A, and the content of the sulfur accounts for 0.2-3.0 wt% of the catalyst A.

8. The regeneration method according to claim 1, wherein: the catalyst A after the regeneration is controlled by the charcoal burning treatment in the step (1) contains sulfur and charcoal, wherein the content of the charcoal is 1.0-2.0 wt% of the catalyst A, and the content of the sulfur accounts for 0.5-2.5 wt% of the catalyst A.

9. The regeneration method according to claim 7 or 8, characterized in that: the content of the sulfur accounts for 1.0-2.0 wt% of the catalyst A.

10. The regeneration method according to claim 1, wherein: the organic compound is one or more of tetrakis hydroxymethyl phosphonium chloride, tetrakis hydroxyethyl phosphonium chloride, tetrakis hydroxypropyl phosphonium chloride, tetrakis hydroxymethyl phosphonium sulfate and tetrakis hydroxypropyl phosphonium sulfate.

11. The regeneration method according to claim 1, wherein: the dosage of the organic compound in the step (2) is 2 to 50 percent of the weight of the catalyst A.

12. The regeneration method according to claim 1 or 11, characterized in that: the dosage of the organic compound in the step (2) is 8 to 40 percent of the weight of the catalyst A.

13. The regeneration method according to claim 1, wherein: the heat treatment temperature in the step (2) is 100-200 ℃, and the heat treatment time is 2-10 hours.

14. The regeneration method according to claim 1 or 13, characterized in that: the heat treatment temperature in the step (2) is 120-180 ℃; the heat treatment time is 2-10 hours.

15. The regeneration method according to claim 1, wherein: the organic sulfide is one or more of mercaptan, carbon disulfide, dimethyl sulfide, thioether and polysulfide, the polysulfide is selected from one or more of organic polysulfides with a general formula of R-Sn-R ', the value of n is 2-10, R and R ' are the same or different and are saturated or unsaturated, straight chain or branched chain, naphthenic base or aromatic base, and the number of carbon atoms of R and R ' is 1-10.

16. The regeneration method according to claim 1, wherein: the dosage of the organic sulfide is 85-150% of the theoretical sulfur demand of the metal component of the hydrogenation catalyst.

17. The regeneration method according to claim 1 or 16, characterized in that: the dosage of the organic sulfide is 95 to 120 percent of the theoretical sulfur demand of the metal component of the hydrogenation catalyst.

18. The regeneration method according to claim 1, wherein: the usage amount of the hydrazine hydrate is 20 to 160 percent of the sum of the sulfur content of the catalyst A and the sulfur content of the organic sulfide.

19. The regeneration method according to claim 1, wherein: the heat treatment temperature in the step (3) is 60-160 ℃, and the heat treatment time is 2-10 hours.

20. The regeneration method according to claim 1 or 19, wherein: the heat treatment temperature in the step (3) is 80-130 ℃; the heat treatment time is 2-10 hours.

21. The regeneration method according to claim 1, wherein: the charcoal burning treatment device adopts one or more of a tunnel kiln, a rotary kiln, a moving bed, a box furnace and a tubular furnace.