A regeneration method for a carbonyl sulfide hydrolysis catalyst

Abstract

The present invention discloses a regeneration method for a carbonyl sulfide hydrolysis catalyst, comprising the following steps: (1) impregnating a deactivated carbonyl sulfide hydrolysis catalyst with a carrier of activated carbon in deionized water at 50-80 °C for 2-4 h, filtering and washing with deionized water to obtain a catalyst washed with water; (2) impregnating the catalyst washed with water in an alkali solution for 1-2 h, filtering and washing with deionized water to obtain a catalyst impregnated with the alkali solution; (3) drying the catalyst impregnated with the alkali solution at 80-120 °C for 3-6 h, then passing hydrogen gas through for calcination at 180-450 °C for 3-6 h, and cooling to room temperature to obtain a calcined catalyst; (4) impregnating the calcined catalyst in a solution containing an active component for 4-24 h, carrying out vacuum drying at 80-120 °C for 3-6 h, and then passing nitrogen gas through for calcination at 300-550 °C for 3-6 h to obtain a regenerated carbonyl sulfide hydrolysis catalyst. The regenerated carbonyl sulfide hydrolysis catalyst of the present invention has the advantages of reducing the residual sulfur content on the surface of the deactivated catalyst or reducing sulfation.

Description

Technical Field

[0001] The present invention relates to a method for regenerating a deactivated catalyst, and more particularly to a method for regenerating a carbonyl sulfide hydrolysis catalyst. Background Art

[0002] Carbonyl sulfide (COS) is a common organic sulfur. In the process of producing chemical feed gas from coal or petroleum, COS is the main organic sulfur component in the feed gas, which will corrode production equipment and is also a poison for many catalysts, and is one of the components that must be removed. At present, the most widely used COS removal technology at home and abroad is mainly the hydrolysis method. The developed carbonyl sulfide hydrolysis catalysts mainly use activated alumina as the main component to convert carbonyl sulfide into hydrogen sulfide under mild conditions as much as possible. After being used for a period of time, the COS hydrolysis catalyst will be deactivated due to sulfur deposition or sulfation and needs to be regenerated.

[0003] Chinese Patent CN1329941A calcines the deactivated catalyst at a certain temperature, washes it with deionized water or ammonia water, and then impregnates it with an impregnating agent containing a metal compound at room temperature. The obtained regenerated catalyst has the same activity as the fresh catalyst, but this regeneration method is prone to loss of active components and a decrease in activity. Chinese Patent CN101670302 discloses a regeneration method for a deactivated carbonyl sulfide hydrolysis catalyst supported on activated carbon. The deactivated catalyst is calcined in a tubular furnace at 150 - 300 °C for 3 - 4 h under N2 protection, then washed with distilled water for 20 - 40 min, dried, and impregnated in an alkaline solution such as Na2CO3 and NaHCO3 for 20 - 40 min, and finally dried at 110 - 130 °C for 3 - 6 h to obtain a regenerated catalyst. The regenerated catalyst can make the COS conversion rate reach more than 95%. This regeneration method has a short washing time with distilled water and impregnation time with an alkaline solution, and the active components of the catalyst are prone to loss. Chinese Patent CN109833863A provides a method combining water washing regeneration and nitrogen thermal regeneration. Although it can wash away some soluble sulfur-containing substances deposited on the catalyst surface during the reaction, it can also wash away the surface basic groups, and there will still be a small amount of sulfur remaining on the surface, reducing the hydrolysis activity of the catalyst. Summary of the Invention

[0004] In order to solve the problem that there is still a small amount of sulfur or sulfation remaining on the surface of the regenerated deactivated catalyst, the present invention provides a method for regenerating a carbonyl sulfide hydrolysis catalyst.

[0005] The method for regenerating the carbonyl sulfide hydrolysis catalyst of the present invention includes the following steps:

[0006] (1) Immerse the deactivated carbonyl sulfide hydrolysis catalyst with activated carbon as the carrier in deionized water at 50 - 80 °C for 2 - 4 h, then filter and wash with deionized water to obtain the catalyst washed with water.

[0007] (2) soaking the washed catalyst in an alkaline solution for 1-2 hours, filtering and washing with deionized water to obtain an alkaline solution-impregnated catalyst;

[0008] (3) drying the catalyst impregnated with alkali solution at 80-120° C. for 3-6 hours, then calcining it at 180-450° C. by introducing hydrogen for 3-6 hours, and cooling it to room temperature to obtain a calcined catalyst;

[0009] (4) After the calcined catalyst is immersed in a solution containing active components for 4-24 hours, it is vacuum dried at 80-120° C. for 3-6 hours, and then calcined at 300-550° C. for 3-6 hours by introducing nitrogen, thereby obtaining a regenerated carbonyl sulfide hydrolysis catalyst.

[0010] In step (1), the activated carbon is modified activated carbon modified by a strong alkaline solution.

[0011] The activated carbon is one or more selected from coconut shell activated carbon, wood activated carbon or coal activated carbon.

[0012] In step (2), the alkaline solution is one or both of a NaOH solution and a KOH solution, and the mass percentage concentration of the alkaline solution is 0.5-5%.

[0013] In step (4), the active component is any one selected from potassium carbonate, sodium carbonate, cesium carbonate, lithium acetate, potassium acetate, sodium acetate, and cesium acetate, and the mass percentage of the active component relative to the amount of the deactivated catalyst is 5-25%.

[0014] Beneficial effects: (1) The regeneration method of the deactivated carbonyl sulfide hydrolysis catalyst of the present invention is mainly applicable to a highly active carbonyl sulfide hydrolysis catalyst with activated carbon as a carrier, and the sulfate on the surface of the deactivated catalyst can be more easily removed by soaking and washing with water and alkaline solution;

[0015] (2) Calcination by introducing hydrogen is beneficial to the removal of oxidation centers and a small amount of sulfur on the surface of the deactivated catalyst;

[0016] (3) The carbonyl sulfide hydrolysis catalyst regeneration method of the present invention has good catalytic activity and can achieve multiple regeneration of the catalyst. DETAILED DESCRIPTION

[0017] The technical solution of the present invention is described in detail below through embodiments, but the protection scope of the present invention is not limited to the embodiments.

[0018] The carrier of the deactivated carbonyl sulfide hydrolysis catalyst used in the following examples is wood-modified activated carbon modified with 2.5% NaOH solution.

[0019] The activity evaluation experiment of the carbonyl sulfide hydrolysis catalyst was carried out in a fixed-bed reactor with a reactor diameter of 6 - 10 mm and a catalyst bed height of 3 - 6 cm. The activity was expressed as the COS hydrolysis rate. Reaction conditions: the COS concentration in the feed gas was 100 - 1000 ppm, and the reaction temperature was 30 - 100 °C.

[0020] Example 1

[0021] (1) Add 5 g of the deactivated carbonyl sulfide hydrolysis catalyst to sufficient deionized water, impregnate it at 50 °C for 2 h, filter and wash it 3 times with deionized water to obtain the catalyst washed with water.

[0022] (2) Immerse the above-mentioned catalyst washed with water in 1% NaOH solution for 1 h, filter and wash it 3 times with deionized water to obtain the catalyst impregnated with alkali solution.

[0023] (3) Dry the above-mentioned catalyst impregnated with alkali solution in an oven at 80 °C for 6 h, then pass hydrogen gas through it in a tubular furnace at 180 °C for 6 h, and cool it to room temperature to obtain the calcined catalyst.

[0024] (4) Immerse the above-mentioned calcined catalyst in 5 g of 5% K2CO3 solution for 4 h, then dry it in a vacuum oven at 80 °C under vacuum for 3 h, and then pass nitrogen gas through it in a tubular furnace at 300 °C for 6 h to obtain the regenerated carbonyl sulfide hydrolysis catalyst 1.

[0025] When using the regenerated carbonyl sulfide hydrolysis catalyst 1 to remove COS, charge 0.5 g of this catalyst into a (Φ6 mm * 120 mm) fixed-bed reactor. Reaction conditions: temperature 75 °C, space velocity 1000 h -1 , COS concentration 300 ppm. The COS hydrolysis activity is shown in Table 1 below.

[0026] Table 1

[0027] Time (h) 1 2 4 6 8 10 COS hydrolysis rate 99.98 99.96 99.88 99.83 99.78 99.75

[0028] Example 2

[0029] (1) Add 5 g of the deactivated carbonyl sulfide hydrolysis catalyst to sufficient deionized water, impregnate it at 80 °C for 1 h, filter and wash it 3 times with deionized water to obtain the catalyst washed with water.

[0030] (2) Immerse the above-mentioned catalyst washed with water in 0.5% NaOH solution for 2 h, filter and wash it 3 times with deionized water to obtain the catalyst impregnated with alkali solution.

[0031] (3) Dry the above-mentioned catalyst impregnated with alkali solution in an oven at 120 °C for 3 h, then pass hydrogen gas through it in a tubular furnace at 300 °C for 4 h, and cool it to room temperature to obtain the calcined catalyst.

[0032] (4) The above-mentioned calcined catalyst was impregnated in 10 g of 12.5% Na2CO3 solution for 24 h, then vacuum-dried at 90 °C for 3 h in a vacuum oven, and then calcined in a tube furnace at 550 °C for 3 h under a nitrogen atmosphere to obtain the regenerated carbonyl sulfide hydrolysis catalyst 2.

[0033] When using the regenerated carbonyl sulfide hydrolysis catalyst 2 to remove COS, 0.5 g of this catalyst was loaded in a (Φ6 mm * 120 mm) fixed-bed reactor, and the reaction conditions were: temperature 75 °C, space velocity 1000 h -1 , and the COS concentration was 300 ppm. The COS hydrolysis activity is shown in Table 2 below.

[0034] Table 2

[0035] Time (h) 1 2 4 6 8 10 COS hydrolysis rate 92.68 92.56 92.42 91.98 91.65 91.35

[0036] Example 3

[0037] (1) 5 g of the deactivated carbonyl sulfide hydrolysis catalyst was added to sufficient deionized water, impregnated at 80 °C for 1 h, filtered and washed 3 times with deionized water to obtain the catalyst washed with water.

[0038] (2) The above-mentioned catalyst washed with water was impregnated in 0.5% NaOH solution for 2 h, filtered and washed 3 times with deionized water to obtain the catalyst impregnated with alkali solution.

[0039] (3) The above-mentioned catalyst impregnated with alkali solution was dried in an oven at 120 °C for 3 h, then calcined in a tube furnace at 300 °C for 4 h under a hydrogen atmosphere, and then cooled to room temperature to obtain the calcined catalyst.

[0040] (4) The above-mentioned calcined catalyst was impregnated in 5 g of 20% C S2 CO3 solution for 8 h, then vacuum-dried at 100 °C for 3 h in a vacuum oven, and then calcined in a tube furnace at 450 °C for 4 h under a nitrogen atmosphere to obtain the regenerated carbonyl sulfide hydrolysis catalyst 3.

[0041] When using the regenerated carbonyl sulfide hydrolysis catalyst 3 to remove COS, 0.5 g of this catalyst was loaded in a (Φ6 mm * 120 mm) fixed-bed reactor, and the reaction conditions were: temperature 75 °C, space velocity 1000 h -1 , and the COS concentration was 300 ppm. The COS hydrolysis activity is shown in Table 3 below.

[0042] Table 3

[0043] Time (h) 1 2 4 6 8 10 COS hydrolysis rate 100 99.98 99.96 99.92 99.89 99.85

[0044] Example 4

[0045] (1) Add 5 g of deactivated carbonyl sulfide hydrolysis catalyst to sufficient deionized water, impregnate it at 60 °C for 2 h, filter and wash it with deionized water three times to obtain the catalyst washed with water.

[0046] (2) Immerse the above catalyst washed with water in 5% NaOH solution for 1 h, filter and wash it with deionized water three times to obtain the catalyst impregnated with alkali solution.

[0047] (3) Dry the above catalyst impregnated with alkali solution in an oven at 70 °C for 3 h, then pass hydrogen and calcine it in a tubular furnace at 450 °C for 3 h, and then cool it to room temperature to obtain the calcined catalyst.

[0048] (4) Immerse the above calcined catalyst in 5 g of 15% CH3COOK solution for 12 h, then vacuum dry it in a vacuum oven at 90 °C for 3 h, and then pass nitrogen and calcine it in a tubular furnace at 450 °C for 5 h to obtain the regenerated carbonyl sulfide hydrolysis catalyst 4.

[0049] When using the regenerated carbonyl sulfide hydrolysis catalyst 4 to remove COS, charge 0.5 g of this catalyst in a (Φ6 mm * 120 mm) fixed-bed reactor, and the reaction conditions are: temperature 75 °C, space velocity 1000 h -1 , COS concentration 300 ppm. The COS hydrolysis activity is shown in Table 4 below.

[0050] Table 4

[0051] Time (h) 1 2 4 6 8 10 COS hydrolysis rate 96.95 96.88 96.64 96.48 96.19 95.95

[0052] Example 5

[0053] (1) Add 5 g of deactivated carbonyl sulfide hydrolysis catalyst to sufficient deionized water, impregnate it at 60 °C for 2 h, filter and wash it with deionized water three times to obtain the catalyst washed with water.

[0054] (2) Immerse the above catalyst washed with water in 2.5% NaOH solution for 1 h, filter and wash it with deionized water three times to obtain the catalyst impregnated with alkali solution.

[0055] (3) Dry the above catalyst impregnated with alkali solution in an oven at 70 °C for 3 h, then pass hydrogen and calcine it in a tubular furnace at 450 °C for 3 h, and then cool it to room temperature to obtain the calcined catalyst.

[0056] (4) Immerse the above calcined catalyst in 6 g of 18% CH3COONa solution for 10 h, then vacuum dry it in a vacuum oven at 110 °C for 3 h, and then pass nitrogen and calcine it in a tubular furnace at 400 °C for 6 h to obtain the regenerated carbonyl sulfide hydrolysis catalyst 5.

[0057] When using the regenerated carbonyl sulfide hydrolysis catalyst 5 to remove COS, 0.5 g of this catalyst was loaded in a fixed-bed reactor (Φ6 mm * 120 mm), and the reaction conditions were: temperature 75 °C, space velocity 1000 h -1 , and the COS concentration was 300 ppm. The COS hydrolysis activity is shown in Table 5 below.

[0058] Table 5

[0059] Time (h) 1 2 4 6 8 10 COS hydrolysis rate 86.92 86.48 85.94 85.46 85.08 84.65

[0060] Example 6

[0061] (1) 5 g of the deactivated carbonyl sulfide hydrolysis catalyst was added to sufficient deionized water, impregnated at 60 °C for 2 h, filtered and washed 3 times with deionized water to obtain the water-washed catalyst.

[0062] (2) The above water-washed catalyst was impregnated in 2% NaOH solution for 2 h, filtered and washed 3 times with deionized water to obtain the catalyst impregnated with the alkali solution.

[0063] (3) The above catalyst impregnated with the alkali solution was dried in an oven at 80 °C for 3 h, then calcined in a tube furnace at 350 °C by passing hydrogen for 3 h, and then cooled to room temperature to obtain the calcined catalyst.

[0064] (4) The above calcined catalyst was impregnated in 8 g of 12% CH3COOCs solution for 15 h, then vacuum-dried in a vacuum oven at 120 °C for 3 h, and then calcined in a tube furnace at 500 °C by passing nitrogen for 5 h to obtain the regenerated carbonyl sulfide hydrolysis catalyst 6.

[0065] When using the regenerated carbonyl sulfide hydrolysis catalyst 6 to remove COS, 0.5 g of this catalyst was loaded in a fixed-bed reactor (Φ6 mm * 120 mm), and the reaction conditions were: temperature 75 °C, space velocity 1000 h -1 , and the COS concentration was 300 ppm. The COS hydrolysis activity is shown in Table 6 below.

[0066] Table 6

[0067] Time (h) 1 2 4 6 8 10 COS hydrolysis rate 98.97 98.69 98.54 98.48 98.26 97.84

[0068] Comparative Example 1

[0069] The method of Chinese Patent CN101670302B (regeneration method for deactivated carbonyl sulfide hydrolysis catalyst supported on activated carbon) was adopted.

[0070] Weigh 5 g of the deactivated carbonyl sulfide hydrolysis catalyst, calcine it at 300 °C for 3 h, wash it with distilled water for 20 - 40 min, dry it at 110 °C for 3 h, then dissolve 0.4 g of Na2CO3 in 10 ml of distilled water, immerse the dried catalyst in the Na2CO3 solution, and finally dry it at 130 °C for 6 h to obtain the regenerated catalyst 6.

[0071] When using the regenerated catalyst 6 to remove COS, charge 0.5 g of this catalyst in a (Φ6 mm * 120 mm) fixed-bed reactor. The reaction conditions are: temperature 75 °C, space velocity 1000 h -1 , and the COS concentration is 300 ppm. The COS hydrolysis activity is as shown in Table 7 below.

[0072] Table 7

[0073] Time (h) 1 2 4 6 8 10 COS hydrolysis rate 80.26 79.89 79.48 78.97 78.64 78.35

[0074] As described above, although the present invention has been shown and described with reference to specific preferred embodiments, it should not be construed as a limitation of the present invention itself. Various changes in form and detail may be made without departing from the spirit and scope of the present invention defined by the appended claims.

Claims

1. A regeneration method for a carbonyl sulfide hydrolysis catalyst, characterized in that, It includes the following steps: (1) Immerse the deactivated carbonyl sulfide hydrolysis catalyst with activated carbon as the carrier in deionized water at 50 - 80 °C for 2 - 4 h, then filter and wash with deionized water to obtain the catalyst washed with water; (2) Immerse the catalyst washed with water in an alkali solution for 1 - 2 h, filter and wash with deionized water to obtain the catalyst impregnated with the alkali solution; (3) Dry the catalyst impregnated with the alkali solution at 80 - 120 °C for 3 - 6 h, then pass hydrogen and calcine at 180 - 450 °C for 3 - 6 h, and then cool to room temperature to obtain the calcined catalyst; (4) Immerse the calcined catalyst in a solution containing an active component for 4 - 24 h, carry out vacuum drying at 80 - 120 °C for 3 - 6 h, and then pass nitrogen and calcine at 300 - 550 °C for 3 - 6 h to obtain the regenerated carbonyl sulfide hydrolysis catalyst; The alkali solution is selected from one or two of NaOH solution and KOH solution, and the mass percentage concentration of the alkali solution is 0.5 - 5%; The active component is selected from any one of potassium carbonate, sodium carbonate, cesium carbonate, lithium acetate, potassium acetate, sodium acetate, and cesium acetate, and the mass percentage of the active component relative to the amount of the deactivated catalyst is 5 - 25%.

2. The regeneration method of the carbonyl sulfide hydrolysis catalyst according to claim 1, wherein In step (1), the activated carbon is modified activated carbon modified with a strong alkali solution.

3. The regeneration method of the carbonyl sulfide hydrolysis catalyst according to claim 1, characterized in that The activated carbon is selected from one or several of coconut shell activated carbon, wood activated carbon, or coal-based activated carbon.