Coking liquid gas carbonyl sulfur hydrolysis catalyst and preparation method thereof

Abstract

The application discloses a coking liquefied gas carbonyl sulfur hydrolysis catalyst and a preparation method thereof, and belongs to the technical field of desulfurization catalysts. The technical scheme is as follows: the inner core is spherical and is composed of Al-Si-Ti; the active component is K, Ga and La; the outer shell is a coating layer composed of C, N-doped Zn-Al-Si; and the preparation method comprises the preparation of the inner core and the coating of the outer shell. The catalyst prepared by the application has a special core-shell structure. On one hand, the carbonyl sulfur hydrolysis active component is in the inner core and is in a buried distribution, so that the peeling and loss of the active component during use can be reduced, and the service life of the catalyst is prolonged.

Description

Technical Field

[0001] The present invention relates to the technical field of desulfurization catalysts, and in particular to a coking liquefied gas carbonyl sulfide hydrolysis catalyst and a preparation method thereof. Background Art

[0002] my country's energy structure is rich in coal, poor in oil, and low in gas, and a large amount of oil needs to be imported. In recent years, the contradiction between oil supply and demand has become increasingly intensified worldwide. The quality of crude oil processed in my country has become increasingly heavy and inferior. Coking, as an important method for improving the quality of inferior oil, has been widely used in refining and chemical companies. Usually, the sulfur content in coking liquefied gas is high, and its actual application value is low. Most of it is only used as fuel, resulting in a waste of resources. The propylene content in this part of liquefied gas is about 12-17wt%, and it usually contains about 200-300ppm of carbonyl sulfide. If this part of propylene can be desulfurized and purified and used in polypropylene or butyl octanol units, the application value of the coking liquefied gas can be greatly improved.

[0003] Carbonyl sulfide (COS) can corrode production equipment and damage the human nervous system. Even trace amounts can cause severe poisoning and deactivation of catalysts. COS can photochemically react to form sulfur dioxide and sulfate aerosols, causing acid rain and significant ecological damage. Because COS is chemically stable and less acidic and polar than hydrogen sulfide, conventional methods for removing hydrogen sulfide are incapable of completely removing COS.

[0004] Currently, commonly used methods for COS removal include reduction, hydrolysis, absorption, adsorption, and oxidation. The reduction method uses H2 to reduce COS to H2S. This method has a high conversion rate, but is also costly and involves certain side reactions. The absorption method uses an alkaline organic amine solution to absorb the acidic COS gas. This method has a fast absorption rate and low cost, but has poor desulfurization selectivity and high energy consumption, making it primarily suitable for crude removal. The adsorption method uses porous solid materials to adsorb low-concentration COS, enriching it on the solid surface and separating it from other components. However, this method requires frequent regeneration and harsh regeneration conditions. The oxidation method oxidizes COS to generate other easily removable sulfides, which are then removed, resulting in a more complex process.

[0005] The hydrolysis method for removing COS typically uses a two-step process. In the first step, a hydrolyzing agent is used to react COS + H₂O = H₂S + CO₂. In the second step, an additional desulfurizer is used to remove the generated H₂S. Commonly used COS hydrolysis catalysts include metal oxide supports such as γ-Al₂O₃ and TiO₂, and non-metal oxide supports such as activated carbon. These catalysts offer advantages such as high activity at room temperature, a wide operating temperature range, strong resistance to poisoning, high efficiency in converting and absorbing organic sulfur, and energy savings. Therefore, the development of a new catalyst that can simultaneously catalyze the hydrolysis of COS and remove the generated H₂S gas would simplify the process, reduce production costs, and enhance the competitiveness of this technology.

[0006] CN 108246298 A invented a method for removing carbonyl sulfide from gas using a nano-layered solid base. Hydrolysis and oxidation reactions occur during the removal process. After COS is hydrolyzed, it is oxidized by dissolved oxygen in water to convert it into elemental sulfur and sulfate. The generated sulfate covers the catalyst surface, easily leading to catalyst deactivation, necessitating frequent regeneration.

[0007] CN 109794251 A provides a method for preparing a carbonyl sulfide hydrolysis catalyst by modifying a zinc-nickel-aluminum-cerium hydrotalcite precursor with a complexing agent. The method comprises preparing a zinc-nickel-aluminum-cerium salt solution and an alkaline solution; co-precipitating the salt solution and the alkaline solution to obtain a hydrotalcite precursor; adding an organic complexing agent for modification; filtering the precipitate and heat-treating it to obtain the desired metal oxide catalyst. However, the method does not simultaneously remove hydrogen sulfide generated by COS hydrolysis.

[0008] CN 112473742 A provides a desulfurization catalyst for simultaneously removing hydrogen sulfide and carbonyl sulfide, and a preparation method thereof. The method comprises: dissolving a metal chelate salt in water, sequentially adding an organic amine, an organic alcohol, a mixed oxide, and sodium carbonate, then heating to 80-90°C for 4-6 hours to obtain a catalyst solution, and drying the solution to obtain a desulfurization catalyst for simultaneously removing hydrogen sulfide and carbonyl sulfide. However, when the catalyst is used on-site, it must be mixed with an alkaline solution having a pH of 9-10 to simultaneously absorb the acidic gases hydrogen sulfide and carbonyl sulfide in the gas, generating a large amount of waste liquid and increasing the difficulty of subsequent treatment. Summary of the Invention

[0009] The technical problem to be solved by the present invention is to overcome the deficiencies of the prior art and provide a catalyst and preparation method for hydrolyzing carbonyl sulfide from coking liquefied petroleum gas, which can simultaneously remove carbonyl sulfide and H2S produced by its hydrolysis.

[0010] The technical solution of the present invention is:

[0011] In the first aspect, a catalyst for hydrolyzing carbonyl sulfide from coking liquefied gas is disclosed, wherein the core is spherical and composed of Al-Si-Ti, the active components are K, Ga and La, and the shell is a coating composed of C and N doped Zn-Al-Si.

[0012] Preferably, the kernel comprises the following components in parts by weight, specifically as follows:

[0013] Molecular sieve 1: 52-80 parts

[0014] Titanium dioxide: 20-35 parts

[0015] Potassium oxide: 3-7 parts

[0016] Gallium oxide: 1-3 parts

[0017] Lanthanum oxide: 2-4 parts

[0018] 0.5-1 part additive

[0019] 0.5-2 parts of binder

[0020] Preferably, the molecular sieve 1 is one or more of HY, HMCM-22, and HZSM-5, the precursor of titanium dioxide is metatitanic acid, and the precursors of potassium oxide, gallium oxide, and lanthanum oxide are potassium nitrate, gallium nitrate, and lanthanum nitrate, respectively.

[0021] In the second aspect, a method for preparing a catalyst for hydrolyzing carbonyl sulfide from coking liquefied gas is disclosed, which includes the preparation of a core and the coating of a shell, as follows:

[0022] The preparation of the S1 core is as follows:

[0023] S11: molecular sieve 1, metatitanic acid, and additives are mixed uniformly to form a solid material;

[0024] S12: Add the binder into water and stir evenly to prepare solution A;

[0025] S13: Rolling the solid material into a rolling mill, spraying Solution A onto the solid material in the rolling mill, rotating the rolling mill to form the solid material into small carrier pellets with a diameter of 1.5-2.5 mm, sieving the spherical carrier particles to obtain small carrier pellets with a diameter of 1.8-2 mm; drying the small carrier pellets at 100-120° C. for 2-6 hours, and calcining them at 400-650° C. for 3-6 hours to obtain a catalyst core carrier;

[0026] S14 impregnation: potassium nitrate, gallium nitrate and lanthanum nitrate, precursors of the active components potassium oxide, gallium oxide and lanthanum oxide, are dissolved in water to prepare solution B. The catalyst core support is added to solution B and impregnated for 3-6 hours;

[0027] S15 drying: drying the impregnated carrier at a temperature of 100-130° C. for 1-4 hours;

[0028] S16 calcination: calcining the dried support at a temperature of 300-600° C. for 3-5 hours to obtain a core of the carbonyl sulfide hydrolysis catalyst;

[0029] The coating method of S2 shell is as follows:

[0030] S21: dispersing the molecular sieve in a solvent to prepare a suspension I;

[0031] S22: adding the zinc source to the suspension I and stirring to obtain a suspension II;

[0032] S23 adding a heterocyclic organic compound containing C and N elements to the suspension II and stirring to obtain a complex;

[0033] S24: adding the catalyst core obtained in step S16 to a sugar coating machine, and coating it with the complex obtained in step S23 to a coating thickness of 0.8-1 mm to obtain coated pellets;

[0034] S25: drying the coated pellets in step S24 at a temperature of 100-130° C. for 1-4 hours; after drying, calcining them at 650-750° C. for 3-5 hours in a nitrogen atmosphere to obtain a coking liquefied gas carbonyl sulfide hydrolysis catalyst.

[0035] Preferably, the auxiliary agent is one of sesbania powder, polyvinyl alcohol, and polyacrylamide; the binder is one of acetic acid, nitric acid, and citric acid, preferably nitric acid.

[0036] Preferably, in step S21, the molecular sieve 2 is one or more of HZSM-23, HBEA, and HMOR, the solvent is one or more of methanol, water, and N,N-dimethylformamide, and the ratio of the mass of the molecular sieve 2 to the volume of the solvent is 1:10-1:50.

[0037] Preferably, in step S21, the ratio of the mass of molecular sieve 2 to the volume of the solvent is 1:20-1:30.

[0038] Preferably, the heterocyclic organic compound containing C and N elements used in step S23 is one or more of 2-methylimidazole, imidazole, pyridine and benzopyridine.

[0039] Preferably, the zinc source in step S22 is zinc nitrate, and the molar ratio of zinc nitrate to the heterocyclic organic compound containing C and N elements can be controlled to be 1-2:2.

[0040] The third aspect discloses the application of a catalyst for the hydrolysis of carbonyl sulfide from coking liquefied petroleum gas. The specific method is as follows: the reaction is carried out in a continuous flow fixed bed reactor. The reaction tube is a tube with an inner diameter of 30 mm, with a 3 mm thermocouple sleeve inserted therein. The catalyst loading amount is 10 mL. The catalyst evaluation conditions are: a space velocity of 3000-6000 h -1 The reaction temperature is 50-70°C and the reaction pressure is normal pressure. A sulfur speciation analyzer is used to detect the sulfur content in the raw materials and the purified gas;

[0041] The hydrolysis rate of COS was calculated according to the following formula: Where: M0 and M1 represent the volume concentration of COS at the reactor inlet and outlet, respectively.

[0042] Compared with the prior art, the present invention has the following beneficial effects:

[0043] 1. The catalyst prepared in the present invention has a unique core-shell structure. On the one hand, the carbonyl sulfide hydrolysis active component is located in the core and is distributed in a buried manner, which can reduce the peeling and loss of the active component during use, thereby extending the service life of the catalyst. On the other hand, due to the presence of the shell layer that removes the hydrogen sulfide active component, the hydrogen sulfide generated during the hydrolysis process can be removed in a timely manner, breaking the equilibrium of the COS + H2O = H2S + CO2 reaction, facilitating the right-hand direction of the hydrolysis reaction, and increasing the rate of the hydrolysis reaction. 2. The catalyst has high activity and good stability. 3. The catalyst preparation method of the present invention is simple, and the raw materials used are all commercially available products, making it suitable for industrial large-scale production. DETAILED DESCRIPTION

[0044] Example 1

[0045] This embodiment provides a method for preparing a catalyst for hydrolyzing carbonyl sulfide from coking liquefied petroleum gas, which is specifically as follows:

[0046] 1) Preparation of the catalyst core: 667 g of HY molecular sieve, 157 g of metatitanic acid, and 20 g of polyvinyl alcohol were weighed and mixed to form a solid material; 15 g of nitric acid was weighed and added to water and stirred to form a solution; the mixed solid material was placed in a ball rolling machine, nitric acid solution was sprayed onto the material in the ball rolling machine, and the ball was formed into small balls with a diameter of 2 mm; the small balls were dried at 120°C for 6 h and calcined at 400°C for 5 h to prepare the catalyst A core carrier;

[0047] Weigh 60g potassium nitrate, 50g gallium nitrate, and 44g lanthanum nitrate and dissolve them in water to make a solution. Add the catalyst A core carrier to the solution and impregnate for 3 hours. Dry the impregnated carrier at 130°C for 4 hours and calcine at 490°C for 5 hours to obtain the catalyst A core.

[0048] 2) Catalyst shell coating:

[0049] 5g of HZSM-23 support was dispersed in 100mL of methanol, stirred, and sonicated to obtain a homogeneous mixture I. 1.5g of zinc nitrate hexahydrate was added to mixture I and stirred at 25°C for 30 minutes to fully dissolve, yielding mixture II. 8.75g of methylimidazole was added to mixture II and stirred at 25°C for 3 hours to obtain a composite. The resulting catalyst A core was placed in a sugar coater and coated with the composite, achieving a coating thickness of approximately 1mm. The coated pellets were then dried at 100°C for 4 hours. After drying, they were calcined at 650°C under a nitrogen atmosphere for 3 hours to obtain catalyst A for the hydrolysis of carbonyl sulfide from coking liquefied petroleum gas.

[0050] Example 2

[0051] This embodiment provides a method for preparing a catalyst for hydrolyzing carbonyl sulfide from coking liquefied petroleum gas, which is specifically as follows:

[0052] Catalyst core preparation: 1561 g HMCM-22 molecular sieve, 167 g metatitanic acid, and 41 g polyvinyl alcohol were weighed and mixed to form a solid material. 37 g nitric acid was weighed and added to water and stirred to form a solution. The mixed solid material was placed in a ball rolling machine, and the nitric acid solution was sprayed on the material in the ball rolling machine. The ball was rolled to form small balls with a diameter of 2 mm. The small balls were dried at 120°C for 4 h and calcined at 470°C for 4 h to prepare the catalyst B core carrier.

[0053] Weigh 118g potassium nitrate, 69g gallium nitrate, and 68g lanthanum nitrate and dissolve them in water to prepare a solution. Add the catalyst B core carrier to the solution and soak for 3 hours. Dry the impregnated carrier at 120°C for 4 hours and calcine at 500°C for 4 hours to obtain the catalyst B core.

[0054] Catalyst housing coating:

[0055] 5g of the HBEA carrier was dispersed in 100mL of methanol, stirred, and sonicated to obtain a homogeneous mixture I. 1.5g of zinc nitrate hexahydrate was added to mixture I and stirred at 25°C for 30 minutes to fully dissolve, yielding mixture II. 8.75g of methylimidazole was added to mixture II and stirred at 25°C for 4 hours to obtain a composite. The resulting catalyst B core was placed in a sugar coater and coated with the composite to a coating thickness of approximately 1mm. The coated pellets were then dried at 100°C for 4 hours. After drying, they were calcined at 650°C under a nitrogen atmosphere for 3 hours to obtain catalyst B for the hydrolysis of carbonyl sulfide from coking liquefied petroleum gas.

[0056] Example 3

[0057] This embodiment provides a method for preparing a catalyst for hydrolyzing carbonyl sulfide from coking liquefied petroleum gas, which is specifically as follows:

[0058] Preparation of the catalyst core: 881 g of HZSM-5 molecular sieve, 257 g of metatitanic acid, and 42 g of Tianqing powder were weighed and mixed uniformly to form a solid material; 31 g of nitric acid was weighed and added to water and stirred uniformly to form a solution; the mixed solid material was placed in a ball rolling machine, nitric acid solution was sprayed on the material in the ball rolling machine, and the ball was rolled to form small balls with a diameter of 2 mm; the small balls were dried at 100°C for 4 h and calcined at 510°C for 4 h to prepare the catalyst C core carrier.

[0059] Weigh 72g of potassium nitrate, 79g of gallium nitrate, and 85g of lanthanum nitrate and dissolve them in water to make a solution. Add the catalyst C core carrier to the solution and soak for 3 hours. Dry the impregnated carrier at 120°C for 4 hours and calcine at 500°C for 4 hours to obtain the catalyst C core.

[0060] Catalyst housing coating:

[0061] 18g of the HMOR support was dispersed in 370mL of methanol, stirred, and sonicated to obtain a homogeneous mixture I. 6g of zinc nitrate hexahydrate was added to mixture I and stirred at 25°C for 30 minutes to fully dissolve, yielding mixture II. 32.3g of methylimidazole was added to mixture II and stirred at 25°C for 5 hours to obtain a composite. The resulting catalyst C core was placed in a sugar coater and coated with the composite to a coating thickness of approximately 1mm. The coated pellets were then dried at 100°C for 4 hours and then calcined at 600°C under a nitrogen atmosphere for 3 hours to obtain catalyst C for the hydrolysis of carbonyl sulfide from coking liquefied petroleum gas.

[0062] Example 4

[0063] This embodiment provides a method for preparing a catalyst for hydrolyzing carbonyl sulfide from coking liquefied petroleum gas, which is specifically as follows:

[0064] Catalyst core preparation: 679 g HZSM-5 molecular sieve, 181 g metatitanic acid, and 34 g polyacrylamide were weighed and mixed uniformly to form a solid material. 31 g nitric acid was weighed and added to water and stirred uniformly to form a solution. The mixed solid material was placed in a ball rolling machine, and the nitric acid solution was sprayed on the material in the ball rolling machine. The ball was rolled to form small balls with a diameter of 2 mm. The small balls were dried at 100°C for 4 h and calcined at 600°C for 4 h to prepare the catalyst D core carrier.

[0065] Weigh 63g of potassium nitrate, 93g of gallium nitrate, and 78g of lanthanum nitrate and dissolve them in water to make a solution. Add the catalyst D core carrier to the solution and impregnate it for 3 hours. Dry the impregnated carrier at 120°C for 4 hours and calcine it at 550°C for 4 hours to obtain the catalyst D core.

[0066] Catalyst housing coating:

[0067] 18g of the HMOR support was dispersed in 450mL of methanol, stirred, and sonicated to obtain a homogeneous mixture I. 7.3g of zinc nitrate hexahydrate was added to mixture I and stirred at 25°C for 30 minutes to fully dissolve, yielding mixture II. 40g of pyridine was added to mixture II and stirred at 25°C for 4 hours to obtain a composite. The core of catalyst D obtained above was placed in a sugar coater and coated with the composite, controlling the coating thickness to approximately 1mm. The coated pellets were then dried at 100°C for 4 hours. After drying, they were calcined at 680°C under a nitrogen atmosphere for 3 hours to obtain catalyst D for the hydrolysis of carbonyl sulfide from coking liquefied petroleum gas.

[0068] Example 5

[0069] This embodiment provides a method for preparing a catalyst for hydrolyzing carbonyl sulfide from coking liquefied petroleum gas, which is specifically as follows:

[0070] Catalyst core preparation: 769 g HZSM-5 molecular sieve, 104 g metatitanic acid, and 14 g polyacrylamide were weighed and mixed uniformly to form a solid material; 28 g nitric acid was weighed and added to water and stirred uniformly to form a solution; the mixed solid material was placed in a ball rolling machine, nitric acid solution was sprayed on the material in the ball rolling machine, and the ball was rolled to form small balls with a diameter of 2 mm; the small balls were dried at 110°C for 3 h and calcined at 600°C for 4 h to prepare the catalyst E core carrier.

[0071] Weigh 85g of potassium nitrate, 54g of gallium nitrate, and 58g of lanthanum nitrate and dissolve them in water to make a solution. Add the catalyst E core carrier to the solution and soak for 3 hours. Dry the impregnated carrier at 120°C for 4 hours and calcine at 550°C for 4 hours to obtain the catalyst E core.

[0072] Catalyst housing coating:

[0073] 33g of the HMOR support was dispersed in 650mL of methanol, stirred, and sonicated to obtain a homogeneous mixture I. 9.7g of zinc nitrate hexahydrate was added to mixture I and stirred at 25°C for 30 minutes to fully dissolve, yielding mixture II. 57g of pyridine was added to mixture II and stirred at 25°C for 4 hours to obtain a composite. The core of catalyst E obtained above was placed in a sugar coater and coated with the composite, controlling the coating thickness to approximately 1mm. The coated pellets were dried at 100°C for 4 hours and then calcined at 680°C under a nitrogen atmosphere for 3 hours to obtain catalyst E for the hydrolysis of carbonyl sulfide from coking liquefied petroleum gas.

[0074] Example 6

[0075] This embodiment provides a method for preparing a catalyst for hydrolyzing carbonyl sulfide from coking liquefied petroleum gas, which is specifically as follows:

[0076] Catalyst core preparation: 772 g HZSM-5 molecular sieve, 171 g metatitanic acid, and 19 g Tianqing powder were weighed and mixed uniformly to form a solid material; 21 g nitric acid was weighed and added to water and stirred uniformly to form a solution; the mixed solid material was placed in a ball rolling machine, nitric acid solution was sprayed on the material in the ball rolling machine, and the ball was rolled to form small balls with a diameter of 2 mm; the small balls were dried at 120°C for 3 h and calcined at 550°C for 3 h to prepare the catalyst F core carrier.

[0077] Weigh 60g potassium nitrate, 107g gallium nitrate, and 91g lanthanum nitrate and dissolve them in water to prepare a solution. Add the catalyst F core carrier to the solution and soak for 3 hours. Dry the impregnated carrier at 120°C for 4 hours and calcine at 550°C for 4 hours to obtain the catalyst F core.

[0078] Catalyst housing coating:

[0079] 41g of the HMOR support was dispersed in 813mL of N,N-dimethylformamide, stirred, and sonicated to obtain a homogeneous mixture I. 12.2g of zinc nitrate hexahydrate was added to mixture I and stirred at 25°C for 30 minutes to fully dissolve, yielding mixture II. 71.3g of pyridine was added to mixture II and stirred at 25°C for 5 hours to obtain a composite. The resulting catalyst F core was placed in a sugar coater and coated with the composite to a coating thickness of approximately 1mm. The coated pellets were then dried at 100°C for 4 hours. After drying, they were calcined at 680°C under a nitrogen atmosphere for 3 hours to obtain catalyst F for the hydrolysis of carbonyl sulfide from coking liquefied petroleum gas.

[0080] Example 7

[0081] This embodiment provides a method for preparing a catalyst for hydrolyzing carbonyl sulfide from coking liquefied petroleum gas, which is specifically as follows:

[0082] Preparation of the catalyst core: Weigh 430g HZSM-5, 320g HMCM-22 molecular sieve, 171g titanic acid, and 19g polyvinyl alcohol respectively, mix them evenly to form a solid material; weigh 18g nitric acid, add it to water, and stir evenly to form a solution; place the mixed solid material in a ball rolling machine, spray nitric acid solution on the material in the ball rolling machine, and rotate the ball rolling machine to obtain small balls with a diameter of 2mm; dry the small balls at 120°C for 3h and calcine at 580°C for 3h to obtain the catalyst G core carrier.

[0083] Weigh 60g potassium nitrate, 107g gallium nitrate, and 91g lanthanum nitrate and dissolve them in water to make a solution. Add the catalyst G core carrier to the solution and soak for 3 hours. Dry the impregnated carrier at 120°C for 4 hours and calcine at 550°C for 4 hours to obtain the catalyst G core.

[0084] Catalyst shell coating:

[0085] 20g of HMOR and 21g of HBEA carrier were dispersed in 813mL of N,N-dimethylformamide, stirred, and sonicated to obtain a homogeneous mixture I. 12.2g of zinc nitrate hexahydrate was added to mixture I and stirred at 25°C for 30 minutes to fully dissolve, yielding mixture II. 71.3g of pyridine was added to mixture II and stirred at 25°C for 5 hours to obtain a composite. The resulting catalyst G core was placed in a sugar coater and coated with the composite, with a coating thickness of approximately 1mm. The coated pellets were then dried at 100°C for 4 hours and then calcined at 680°C under a nitrogen atmosphere for 3 hours to obtain catalyst G for the hydrolysis of carbonyl sulfide from coking liquefied petroleum gas.

[0086] Example 8

[0087] This embodiment provides a method for preparing a catalyst for hydrolyzing carbonyl sulfide from coking liquefied petroleum gas, which is specifically as follows:

[0088] Catalyst core preparation: 427 g HY, 500 g HMCM-22 molecular sieve, 103 g metatitanic acid, and 42 g polyvinyl alcohol were weighed and mixed to form a solid material. 39 g nitric acid was weighed and added to water and stirred to form a solution. The mixed solid material was placed in a ball rolling machine, and the nitric acid solution was sprayed onto the material in the ball rolling machine. The ball was rolled to form small balls with a diameter of 2 mm. The small balls were dried at 120°C for 3 h and calcined at 580°C for 3 h to prepare the catalyst H core support.

[0089] Weigh 93g of potassium nitrate, 78g of gallium nitrate, and 71g of lanthanum nitrate and dissolve them in water to make a solution. Add the catalyst H core carrier to the solution and soak for 3 hours. Dry the impregnated carrier at 120°C for 4 hours and calcine at 600°C for 4 hours to obtain the catalyst H core.

[0090] Catalyst housing coating:

[0091] 20g of HZSM-23 and 19.5g of HBEA support were dispersed in 789mL of methanol, stirred, and sonicated to obtain a homogeneous mixture I. 12.8g of zinc nitrate hexahydrate was added to mixture I and stirred at 25°C for 30 minutes to fully dissolve, yielding mixture II. 69.3g of pyridine was added to mixture II and stirred at 25°C for 5 hours to obtain a composite. The resulting catalyst H core was placed in a sugar coater and coated with the composite, maintaining a coating thickness of approximately 1mm. The coated pellets were then dried at 100°C for 4 hours. After drying, they were calcined at 750°C under a nitrogen atmosphere for 3 hours to obtain catalyst H for the hydrolysis of carbonyl sulfide from coking liquefied petroleum gas.

[0092] Comparative Example 1

[0093] This embodiment provides a method for preparing a catalyst for hydrolyzing carbonyl sulfide from coking liquefied petroleum gas, which is specifically as follows:

[0094] Catalyst core preparation: 769 g of pseudo-boehmite, 104 g of metatitanic acid, and 14 g of polyacrylamide were weighed and mixed uniformly to form a solid material. 28 g of nitric acid was weighed and added to water and stirred uniformly to form a solution. The mixed solid material was placed in a ball rolling machine, and the nitric acid solution was sprayed onto the material in the ball rolling machine. The ball was rolled to form small balls with a diameter of 2 mm. The small balls were dried at 110°C for 3 h and calcined at 600°C for 4 h to prepare the catalyst I core support.

[0095] Weigh 85g of potassium nitrate, 54g of gallium nitrate, and 58g of lanthanum nitrate and dissolve them in water to make a solution. Add the core support of Catalyst I to the solution and soak for 3h. Dry the impregnated support at 120°C for 4h and calcine at 550°C for 4h to obtain the core of Catalyst E.

[0096] Catalyst housing coating:

[0097] 33g of the HMOR support was dispersed in 650mL of methanol, stirred, and sonicated to obtain a homogeneous mixture I. 9.7g of zinc nitrate hexahydrate was added to mixture I and stirred at 25°C for 30 minutes to fully dissolve, yielding mixture II. 57g of pyridine was added to mixture II and stirred at 25°C for 4 hours to obtain a composite. The core of catalyst I obtained above was placed in a sugar coater and coated with the composite, controlling the coating thickness to approximately 1mm. The coated pellets were then dried at 100°C for 4 hours. After drying, they were calcined at 680°C under a nitrogen atmosphere for 3 hours to obtain catalyst I for the hydrolysis of carbonyl sulfide from coking liquefied petroleum gas.

[0098] Comparative Example 2

[0099] This embodiment provides a method for preparing a catalyst for hydrolyzing carbonyl sulfide from coking liquefied petroleum gas, which is specifically as follows:

[0100] 430 g HZSM-5, 320 g HMCM-22 molecular sieve, 171 g metatitanic acid, and 19 g polyvinyl alcohol were weighed and mixed uniformly to form a solid material; 18 g nitric acid was weighed and added to water and stirred uniformly to form a solution; the mixed solid material was placed in a ball rolling machine, nitric acid solution was sprayed on the material in the ball rolling machine, and the ball was formed into small balls with a diameter of 3 mm; the small balls were dried at 120°C for 3 h and calcined at 580°C for 3 h to prepare a catalyst J carrier.

[0101] 60 g of potassium nitrate, 107 g of gallium nitrate, and 91 g of lanthanum nitrate were weighed and dissolved in water to prepare a solution. The core carrier of catalyst G was added to the solution and impregnated for 3 h. The impregnated carrier was dried at 120°C for 4 h and calcined at 550°C for 4 h to obtain catalyst J.

[0102] Example 9

[0103] Example 9 is an application example of the catalyst prepared in Examples 1-8 and Comparative Examples 1 and 2. The specific method is as follows: The reaction was carried out in a continuous flow fixed bed reactor. The reaction tube used was a tube with an inner diameter of 30 mm and a 3 mm thermocouple sleeve inserted inside. The catalyst loading was 10 ml, and the catalyst evaluation conditions were: a space velocity of 3000 h -1 The reaction temperature is 50℃ and the reaction pressure is normal pressure. The raw material is coking liquefied gas, in which the carbonyl sulfide content is 230ppm. The COS and H2S content in the raw material and the purified gas is detected by a sulfur analyzer, and the COS and H2S content in the raw material and the purified gas are calculated according to the formula Where: M0 and M1 represent the volume concentration of COS at the reactor inlet and outlet, respectively. The COS hydrolysis conversion rate was calculated. The results are shown in Table 1.

[0104] Table 1 Catalyst hydrolysis activity

[0105]

[0106] From Table 1, it can be seen that the catalysts prepared in Examples 1-8 have high activity and good stability when applied in a continuous flow fixed bed reactor, and have good conversion of carbonyl sulfur and can simultaneously absorb hydrogen sulfide in the device. The catalyst prepared in Comparative Example 1 has significantly lower conversion of carbonyl sulfur when applied in a continuous flow fixed bed reactor, because the strong acidity of the molecular sieve selected in Examples 1-8 promotes the hydrolysis reaction of carbonyl sulfur, and the pores of the molecular sieve itself provide more active reaction sites to promote the reaction. Comparative Example 2 does not have a coated shell and cannot simultaneously absorb hydrogen sulfide in the reactor.

[0107] The catalyst prepared in the present application has a special core-shell structure. On the one hand, the carbonyl sulfur hydrolysis active component is in the core and is distributed in a buried manner, which can reduce the peeling and loss of the active component during use, thereby prolonging the service life of the catalyst. On the other hand, the presence of the shell layer of the hydrogen sulfide removal active component can timely remove the hydrogen sulfide produced in the hydrolysis process, break the equilibrium of the reaction COS+H2O=H2S+CO2, and facilitate the rightward progress of the hydrolysis reaction, thereby improving the hydrolysis reaction rate. The catalyst has high activity and good stability. The preparation method of the catalyst in the present application is simple, the raw materials used are all commercially available products, and is suitable for large-scale industrial production.

[0108] Although the present application has been described in detail with reference to the preferred embodiments, the present application is not limited to this. Any modifications or replacements made by those skilled in the art to the embodiments of the present application without departing from the spirit and essence of the present application shall be included in the scope of the present application. Any modifications or replacements made by those skilled in the art to the technical scope disclosed in the present application shall be included in the protection scope of the present application. Therefore, the protection scope of the present application shall be subject to the protection scope of the claims.

Claims

1. A catalyst for hydrolyzing carbonyl sulfide from coking liquefied petroleum gas, characterized in that: The core is spherical and composed of Al-Si-Ti, with active components of K, Ga and La, and the shell is a coating composed of C- and N-doped Zn-Al-Si; The preparation method of the carbonyl sulfide hydrolysis catalyst for coking liquefied gas includes the preparation of the core and the coating of the shell, as follows: The preparation of the S1 core is as follows: S11: mixing molecular sieve 1, metatitanic acid, and an additive to form a solid material; the additive is one of sesbania powder, polyvinyl alcohol, and polyacrylamide; S12: adding a binder to water and stirring evenly to form solution A; the binder is one of acetic acid, nitric acid, and citric acid; S13 rolling ball, placing the solid material in a rolling ball machine, spraying solution A on the solid material in the rolling ball machine, rotating the rolling ball until the raw material is formed into carrier balls with a diameter of 1.5-2.5 mm, sieving the carrier spherical particles to obtain carrier balls with a diameter of 1.8-2 mm; drying the carrier balls at 100-120°C for 2-6 hours and calcining at 400-650°C for 3-6 hours to obtain a catalyst core carrier; S14 impregnation: potassium nitrate, gallium nitrate and lanthanum nitrate, precursors of the active components potassium oxide, gallium oxide and lanthanum oxide, are dissolved in water to prepare solution B. The catalyst core support is added to solution B and impregnated for 3-6 hours; S15 drying: drying the impregnated carrier at a temperature of 100-130° C. for 1-4 hours; S16 calcination: calcining the dried support at a temperature of 300-600° C. for 3-5 hours to obtain a core of the carbonyl sulfide hydrolysis catalyst; The coating method of S2 shell is as follows: S21: dispersing the molecular sieve in a solvent to prepare a suspension I; S22: adding the zinc source to the suspension I and stirring to obtain a suspension II; S23 adding a heterocyclic organic compound containing C and N elements to the suspension II and stirring to obtain a complex; S24: adding the catalyst core obtained in step S16 to a sugar coating machine, and coating it with the complex obtained in step S23 to a coating thickness of 0.8-1 mm to obtain coated pellets; S25: drying the coated pellets in step S24 at a temperature of 100-130° C. for 1-4 hours; after drying, calcining them at 650-750° C. for 3-5 hours in a nitrogen atmosphere to obtain a coking liquefied gas carbonyl sulfide hydrolysis catalyst.

2. The catalyst for hydrolyzing carbonyl sulfide from coking liquefied gas according to claim 1, wherein The core comprises the following components in parts by weight: Molecular sieve 1: 52-80 parts Titanium dioxide: 20-35 parts Potassium oxide: 3-7 parts Gallium oxide: 1-3 parts Lanthanum oxide: 2-4 parts 0.5-1 part additive 0.5-2 parts of adhesive.

3. The catalyst for hydrolyzing carbonyl sulfide from coking liquefied gas according to claim 2, wherein: The molecular sieve 1 is one or more of HY, HMCM-22, and HZSM-5. The precursor of titanium dioxide is metatitanic acid. The precursors of potassium oxide, gallium oxide, and lanthanum oxide are potassium nitrate, gallium nitrate, and lanthanum nitrate, respectively.

4. The catalyst for hydrolyzing carbonyl sulfide from coking liquefied gas according to claim 1, wherein The binder is nitric acid.

5. The catalyst for hydrolyzing carbonyl sulfide from coking liquefied gas according to claim 1, wherein In step S21, the molecular sieve 2 is one or more of HZSM-23, HBEA, and HMOR, the solvent is one or more of methanol, water, and N,N-dimethylformamide, and the ratio of the mass of the molecular sieve 2 to the volume of the solvent is 1:10-1:

50.

6. The catalyst for hydrolyzing carbonyl sulfide from coking liquefied gas according to claim 1, wherein In step S21, the ratio of the mass of molecular sieve 2 to the volume of the solvent is 1:20-1:

30.

7. The catalyst for hydrolyzing carbonyl sulfide from coking liquefied gas according to claim 1, wherein The heterocyclic organic compound containing C and N elements used in step S23 is one or more of 2-methylimidazole, imidazole, pyridine and benzopyridine.

8. The catalyst for hydrolyzing carbonyl sulfide from coking liquefied gas according to claim 1, wherein The zinc source in step S22 is zinc nitrate, and the molar ratio of zinc nitrate to the heterocyclic organic compound containing C and N elements is 1-2:

2.

9. Use of the catalyst for hydrolyzing carbonyl sulfide from coking liquefied petroleum gas according to claim 1 in hydrolyzing carbonyl sulfide from coking liquefied petroleum gas, characterized in that: The specific method is as follows: the reaction is carried out in a continuous flow fixed bed reactor, the reaction tube is a tube with an inner diameter of 30 mm, and a 3 mm thermocouple sleeve is inserted inside; the catalyst loading amount is 10 mL, and the catalyst evaluation conditions are: the space velocity is 3000-6000 h -1 The reaction temperature is 50~70℃, the reaction pressure is normal pressure, and the sulfur content in the raw materials and the purified gas is detected by a sulfur speciation analyzer; The hydrolysis rate of COS was calculated according to the following formula: , where: M0 and M1 represent the volume concentrations of COS at the reactor inlet and outlet, respectively.

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