Integrated desulfurization catalyst, preparation method and application thereof

Abstract

The application provides an integrated desulfurization catalyst applied to a process for preparing butyl octanol from coking propylene, the catalyst is a core-shell structure, the inner shell comprises a carrier and an active component; the carrier comprises alumina, silicon dioxide and titanium oxide, and the active component comprises potassium oxide, gallium oxide and lanthanum oxide; the outer shell is a C and N doped compound, and the compound comprises zinc oxide, alumina and silicon dioxide. The application also provides a preparation method of the catalyst, a method for realizing deep desulfurization of coking propylene by using the catalyst and a method for preparing butyl octanol. By using the application, deep desulfurization of coking propylene can be realized, the requirement of coking propylene into a carbonyl synthesis reactor can be met, upgraded utilization of coking propylene is realized, and more choices are provided for the source of carbonyl synthesis propylene raw materials. The preparation method of the integrated desulfurization catalyst is simple, all the raw materials are commercially available products, and the method is suitable for industrial large-scale production.

Description

Technical Field

[0001] This invention relates to a desulfurization catalyst, its preparation method, and its application. Specifically, it relates to an integrated desulfurization catalyst and its preparation method used in the process of preparing butanol and octanol from coking propylene, as well as the use of the catalyst for deep desulfurization of coking propylene and the use of the method to prepare butanol and octanol. Background Technology

[0002] my country's energy structure is characterized by abundant coal, scarce oil, and limited natural gas, necessitating substantial oil imports. In recent years, the global oil supply-demand imbalance has intensified. The quality of crude oil processed in my country is increasingly becoming heavier and lower-grade. Coking, as an important method for upgrading and utilizing low-grade oil, is widely used in refining enterprises. However, coking liquefied petroleum gas (LPG) typically has a high sulfur content, resulting in low practical application value, and is mostly used only as fuel, leading to resource waste. This portion of LPG contains approximately 12-17 wt% propylene, usually containing around 200-300 ppm of carbonyl sulfide, as well as trace amounts of hydrogen sulfide, mercaptans, and macromolecular sulfides. Macromolecular sulfides, in particular, besides hydrogen sulfide and mercaptans, are difficult to remove. If this portion of propylene could be desulfurized and purified for use in butanol / octanol units, the application value of coking liquefied gas could be significantly improved.

[0003] Currently, most butanol and octanol plants employ the Davy / DOW low-pressure rhodium catalyst carbonyl synthesis process. This process uses propylene and syngas (CO, H2) as feedstocks, producing butyraldehyde via a low-pressure liquid-phase circulation method under the action of a rhodium-phosphine catalyst. Butanol and octanol are then obtained through condensation and hydrogenation reactions. The rhodium-phosphine catalyst, a complex with rhodium atoms as the active center and triphenylphosphine and carbon monoxide as ligands, is the core of the carbonyl synthesis reaction, and its activity is crucial for the plant's production. Sulfides in propylene easily lead to catalyst deactivation. According to the control indicators provided by the technology supplier, the total sulfur content of propylene should be below 0.1 ppm. Currently, butanol and octanol plants mainly use polymer-grade propylene from ethylene plants and catalytic propylene from catalytic cracking units as feedstocks. There are currently no reports of using coking propylene as a feedstock for butanol and octanol plants. Compared to cracked propylene and catalytic propylene, refinery coking propylene is relatively cheaper and can bring better economic benefits. However, it is currently difficult to remove sulfur from coking propylene to 0.1 ppm, requiring multi-stage removal processes and a complex process flow.

[0004] The typical hydrolysis method for COS removal employs a two-step process. The first step uses a hydrolyzing agent to initiate the reaction COS + H₂O = H₂S + CO₂. The second step requires the removal of the generated H₂S using an additional desulfurizing agent. Commonly used COS hydrolysis catalysts include metal oxide-based supports such as γ-Al₂O₃ and TiO₂, and non-metal oxide-based 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, developing novel catalysts 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.

[0005] CN 108246298 A discloses a method for removing carbonyl sulfur from gas using a nanolayered solid alkali. During the removal process, hydrolysis and oxidation reactions occur. After hydrolysis, COS is converted into elemental sulfur and sulfate by the oxidation of dissolved oxygen in water. The generated sulfate covers the surface of the catalyst, which can easily lead to catalyst deactivation, thus requiring frequent regeneration.

[0006] CN 107201254 B discloses a method for refining mixed liquefied petroleum gas (LPG). The refining method involves feeding coking LPG into the riser reactor of a catalytic cracking unit, where it undergoes a cracking reaction together with the catalytic cracking feed. The resulting LPG is then distilled from the fractionation system of the catalytic cracking unit, becoming a mixed LPG containing catalytic LPG. This mixed LPG is then fed into a hydrogen sulfide extraction unit and a mercaptan extraction unit to remove hydrogen sulfide and mercaptan, respectively. The sulfur content of the desulfurized LPG product is no greater than 10 μg / g. This patent does not specify the sulfur content of the purified propylene.

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

[0008] CN 112473742 A discloses a desulfurization catalyst for simultaneously removing hydrogen sulfide and carbonyl sulfide, and its preparation method. The method includes: dissolving a metal chelating agent salt in water, sequentially adding an organic amine, an organic alcohol, a mixed oxide, and sodium carbonate, then heating to 80-90℃ and reacting for 4-6 hours to obtain a catalyst solution. After drying, the desulfurization catalyst for simultaneously removing hydrogen sulfide and carbonyl sulfide is obtained. However, when this catalyst is used in the field, it needs to be mixed with an alkaline solution with a pH of 9-10 to simultaneously absorb the acidic gases hydrogen sulfide and carbonyl sulfide from the gas, generating a large amount of waste liquid and increasing the difficulty of subsequent treatment.

[0009] CN 209178263 U discloses a method for preparing butanol and octanol using propylene (refinery propylene), a byproduct of a refinery catalytic cracking unit. The process described in this invention utilizes inexpensive refinery propylene as a feedstock for the butanol and octanol unit, optimizing resource allocation, overcoming production load bottlenecks, reducing raw material costs, and maximizing efficiency. Summary of the Invention

[0010] Coking propylene has a high sulfur content. In addition to trace amounts of hydrogen sulfide and mercaptans, it also contains large molecular sulfides that are difficult to remove by conventional methods. This results in low quality and low utilization rate of coking propylene. Most of it is used as fuel together with coking liquefied gas, which leads to a waste of C3 resources.

[0011] To address the aforementioned problems, this invention provides an integrated desulfurization catalyst and its preparation method. The catalyst is applied to the carbonyl sulfur hydrolysis process of coking propylene to achieve deep desulfurization of the coking propylene, thereby ensuring that the product meets the feed requirements for the Davy / DOW low-pressure rhodium catalyst carbonyl synthesis of butanol and octanol, achieving high-quality utilization of coking propylene. This invention also provides a method for deep desulfurization of coking propylene using the aforementioned catalyst. The integrated desulfurization catalyst simultaneously removes carbonyl sulfur and the hydrogen sulfide generated from its hydrolysis, further reducing the total sulfur in the coking propylene to 0.1 ppm using conventional adsorption methods. The purified coking propylene is then used as a carbonyl synthesis feedstock in a carbonyl synthesis reactor to prepare butanol and octanol. This invention provides a method for preparing butanol and octanol using the aforementioned catalyst.

[0012] The method for preparing butanol and octanol from coking propylene as a raw material according to the present invention includes the following steps:

[0013] The first step: regeneration and modification of spent catalytic cracking catalysts.

[0014] The second step: The regenerated and modified catalytic cracking catalyst enters the riser reactor, where a thermal cracking reaction occurs, converting the large molecular sulfides that are difficult to remove from the coking propylene into small molecular sulfides.

[0015] The third step: The coking propylene and small molecule sulfides produced in the catalytic thermal cracking process enter the hydrolysis reactor. Under the action of the integrated desulfurization catalyst, carbonyl sulfur hydrolysis reaction occurs, and hydrogen sulfide produced in the hydrolysis process is removed. The total sulfur in the coking propylene is further reduced to 0.1 ppm by a combination of ZnO and activated carbon adsorbents.

[0016] Step 4: The purified coking propylene is used as a carbonyl synthesis feedstock and enters the carbonyl synthesis reactor. After the reaction, the material passes through the aldehyde distillation unit, condensation unit, octenal hydrogenation unit, octanol distillation unit, butyraldehyde hydrogenation unit and butanol distillation unit in sequence to finally obtain the butanol and octanol product.

[0017] Specifically, the first step of the present invention includes the following steps:

[0018] Step a1: The coking process of spent catalytic cracking catalyst, in order to better achieve coking and catalyst removal.

[0019] To address any residual organic matter within the reactor channels, this step involves two coking processes. The reaction conditions for these two coking processes are as follows: reactor inlet temperature 450-620℃, nitrogen space velocity 800-1500 h⁻¹. -1 Air velocity 60-650 h -1 The charring time is 2-9 hours.

[0020] Step a2: Preparation of CuY molecular sieve: NaY molecular sieve is subjected to ion exchange with 0.2-1 mol / L nitric acid aqueous solution and 0.2-1 mol / L copper nitrate aqueous solution in sequence for 2-8 h. After filtration and drying, CuY molecular sieve is finally obtained.

[0021] Step a3: Modification and regeneration of the catalytic cracking catalyst. The catalytic cracking catalyst that has undergone primary and secondary coking is mixed with the CuY molecular sieve prepared in steps 1-2 at a mass ratio of 3:1-7:1. Deionized water or ethanol is added and stirred to prepare a slurry. The slurry is then ground in a grinder until the solid particles have a particle size of less than 3 μm. The mass of deionized water or ethanol used is 15-35% of the mass of the catalytic cracking catalyst. The stirring time for the slurry is 30-70 min, and the rotation speed is 100-300 r / min. -1 The grinding speed is 200-400 r / min. -1 The grinding time is 40 to 120 minutes.

[0022] The slurry obtained above is spray-dried at 650-800℃ for 2-6 hours, and then cured at 550-750℃ for 2-6 hours. The preferred curing temperature is 550-630℃, and the curing time is 3-5 hours. The resulting catalyst has a particle size of 30-95 μm for 60-70 wt% of its particles after curing.

[0023] This invention, through the regeneration and modification of spent catalytic cracking catalysts, not only solves the environmental problems caused by improper disposal of spent catalysts, but also realizes a higher utilization value for spent catalysts.

[0024] The reaction temperature of the second step in this invention is 350-420℃.

[0025] The integrated desulfurization catalyst used in the third step of this invention is a coking propylene carbonyl sulfur hydrolysis catalyst, which has a unique core-shell structure. The core is a 2mm sphere, and the outer shell is a 1mm coating. The core consists of a support and active components. The support includes alumina, silica, and titanium dioxide, and the active components include potassium oxide, gallium oxide, and lanthanum oxide. The outer shell is a C / N doped composite, which includes zinc oxide, alumina, and silica. The desulfurization process of coking propylene is as follows: coking propylene diffuses through the outer shell of the integrated desulfurization catalyst to the core, where it undergoes a COS hydrolysis reaction. The resulting H2S diffuses to the outer shell, where it is captured, thus completing a full sulfide removal process.

[0026] This invention provides the coking propylene carbonyl sulfur hydrolysis catalyst and its preparation method, which includes two processes: core preparation and shell preparation.

[0027] In the core preparation process, titanium oxide and active components are introduced in the form of precursors, wherein the precursor of titanium oxide is metatitanic acid, and the precursors of potassium oxide, gallium oxide and lanthanum oxide are added in the form of potassium nitrate, gallium nitrate and lanthanum nitrate, respectively.

[0028] The calculation principle for the amount of titanium oxide precursor and active component precursor is based on the weight parts of oxide; according to the calculation principle, the weight parts of molecular sieve and oxide required for core preparation are: molecular sieve 52-80 parts, titanium oxide 20-35 parts, potassium oxide 3-7 parts, gallium oxide 1-3 parts, and lanthanum oxide 2-4 parts.

[0029] Among them, the molecular sieve is any one or more of HY, HMCM-22, and HZSM-5. The reason for choosing the above molecular sieves is that HY, HMCM-22, and HZSM-5 molecular sieves have relatively weak acidity, which can be used to adjust the overall acidity of carbonyl sulfur hydrolysate, thereby playing a synergistic catalytic role with the metal components in carbonyl sulfur hydrolysate.

[0030] Specifically, the catalyst core preparation process includes the following steps:

[0031] Step b1: Mix the molecular sieve, metatitanic acid, and additives evenly to form a solid material.

[0032] Step b2: Add the adhesive to water and stir until it is evenly mixed to prepare solution A.

[0033] Step b3, Ball rolling: Place the solid material in the ball rolling machine, spray solution A into the material in the ball rolling machine, rotate the ball rolling machine to form the ball until the raw material is formed into small balls with a diameter of about 2mm. Screen the spherical particles to obtain spherical carriers with a diameter of 2mm.

[0034] Step b4, Impregnation: Dissolve the precursors of the active components potassium oxide, gallium oxide and lanthanum oxide in water to prepare solution B, and add the carrier to solution B for impregnation for 3-6 hours.

[0035] Step b5, Drying: Dry the impregnated carrier at a temperature of 100-130℃ for 1-4 hours.

[0036] Step b6, calcination: calcinate the dried support at 300-600℃ for 3-5 hours to obtain the carbonyl sulfur hydrolysis catalyst core.

[0037] In step b1 above, in order to achieve better mixing and binding, the additive is one of guar gum powder, polyvinyl alcohol, and polyacrylamide; the binder is any one of acetic acid, nitric acid, or citric acid, preferably nitric acid.

[0038] Specifically, the preparation process of the catalyst shell includes the following steps:

[0039] Step c1: Disperse the molecular sieve in a solvent to prepare suspension I; based on the inventor's extensive practical experience, such as the need for the molecular sieve to have certain shape selectivity when selecting the molecular sieve for the catalyst shell, the molecular sieve used is any one or more of HZSM-23, HBEA, or HMOR; the solvent used includes any one or a combination of methanol, water, or N,N-dimethylformamide; the mass ratio of the molecular sieve to the volume of the solvent is 1:10-1:50, more preferably 1:20-1:30.

[0040] Step c2: Add the zinc source to suspension I and stir to obtain suspension II; wherein the zinc source is zinc nitrate.

[0041] Step c3: Add the heterocyclic organic compound containing C and N elements to suspension II and stir to obtain a suspension of the complex. In order to enable the catalyst to better adsorb sulfides, it is also necessary to introduce C and N elements. In this invention, heterocyclic organic compounds containing C and N elements are used as the source of C and N elements. Based on extensive practical experience, the heterocyclic organic compounds containing C and N elements used in this invention include one or a combination of several of 2-methylimidazole, imidazole, pyridine, benzopyridine, etc.

[0042] Step c4: Add the catalyst core obtained above into a coating machine and coat it with the suspension of the complex obtained in step c3, controlling the coating thickness to be about 1 mm.

[0043] After coating in steps c5 and c4, the small balls are dried at 100-130℃ for 1-4 hours; after drying, they are calcined at 650-750℃ for 3-5 hours under a nitrogen atmosphere to obtain the carbonyl sulfur hydrolysis catalyst of the present invention for coking liquefaction gas.

[0044] In step c2, the molar ratio of the zinc source to the heterocyclic organic compound containing C and N elements in step c3 can be controlled to be 1:2-2:2.

[0045] The integrated desulfurization catalyst provided by this invention can catalyze the hydrolysis reaction of carbonyl sulfur and simultaneously remove hydrogen sulfide generated during the hydrolysis process. This disrupts the equilibrium of the reaction COS + H₂O = H₂S + CO₂, favoring the rightward progression of the hydrolysis reaction and increasing its rate. The catalyst exhibits high activity and good stability. The catalyst preparation method of this invention is simple, using commercially available raw materials, making it suitable for large-scale industrial production.

[0046] As described above, after partial removal of carbonyl sulfur and hydrogen sulfide by an integrated desulfurization catalyst, the total sulfur in the coking propylene is further reduced to 0.1 ppm using a combination of ZnO and activated carbon adsorbents. The mass ratio of ZnO to activated carbon is 1:3-1:6, and the propylene space velocity is 1000-2600 h⁻¹. -1 .

[0047] The combined purification method provided by this invention enables deep desulfurization of coking propylene, meeting the requirements for feeding coking propylene into the carbonyl synthesis reactor and achieving improved utilization of coking propylene. This deep purification of coking propylene broadens its application range and provides more options for the source of raw materials for carbonyl synthesis of propylene.

[0048] After purification, the coking propylene enters the carbonyl synthesis unit to complete the fourth step described in this invention. Specifically, the carbonyl synthesis unit comprises two carbonyl synthesis reactors connected in series: a low-pressure carbonyl synthesis reaction is carried out in the presence of a rhodium-Parker catalyst, with stirring by a stirrer, an operating temperature of 85-110°C, and an operating pressure of 1.8 MPag. The reaction solution is separated by a catalyst to obtain n- / isobutyraldehyde, and the catalyst solution is recycled back to the reaction system to continue participating in the reaction. n- / isobutyraldehyde enters the aldehyde distillation unit to remove light components, then passes through an isomerization column to separate n-butyraldehyde and isobutyraldehyde, with isobutyraldehyde being the product. The separated n-butyraldehyde is sent to a series of condensation reactors and an alcohol-aldehyde condensation recycling column. In the condensation unit, under conditions of an alkaline catalyst, stirring, operating temperature of 120°C, and operating pressure of 0.40 MPa, a condensation reaction occurs to produce octenal and water. After passing through a chromatography column, octenal reacts with hydrogen in a gas-phase hydrogenation reactor containing a catalyst, directly hydrogenating to produce crude octanol under operating conditions of 0.45 MPa and 200°C. Crude octanol continues to enter a liquid-phase hydrogenation reactor, undergoing liquid-phase hydrogenation at a pressure of 2.60 MPa and a temperature of 85°C, followed by distillation to obtain the product octanol. Butyraldehyde can be further hydrogenated and distilled to obtain butanol. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions in the embodiments of this disclosure will be clearly and completely described below in conjunction with the embodiments of this disclosure. Obviously, the described embodiments are only some embodiments of this disclosure, and not all embodiments. Based on the embodiments in this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0050] Example 1

[0051] Regeneration and modification of spent catalytic cracking catalysts:

[0052] 1. The coking process of spent catalytic cracking catalyst includes two coking steps to better achieve coking and remove any residual organic matter within the catalyst pores.

[0053] (1) First coking, slightly positive pressure, reactor inlet temperature 555℃, nitrogen space velocity 1000h -1 air velocity 100 h -1 The charring time is 3 hours.

[0054] (2) Second coking, slightly positive pressure, reactor inlet temperature 570℃, nitrogen space velocity 1000h -1 air speed 270 h -1 The charring time is 5 hours.

[0055] 2. Preparation of CuY molecular sieve: First, 650g of NaY molecular sieve was subjected to ion exchange with a 0.25mol / L nitric acid aqueous solution for 3 hours; then, the obtained HY molecular sieve was subjected to ion exchange with a 0.25mol / L copper nitrate aqueous solution for 4 hours. After filtration and drying, CuY molecular sieve was finally obtained.

[0056] 3. Modification and regeneration of the catalytic cracking catalyst: The catalytic cracking catalyst that has undergone primary and secondary coking and the CuY molecular sieve prepared in step 2 are mixed at a mass ratio of 5:1. Deionized water is added and stirred to prepare a slurry. The slurry is then ground in a grinder until the solid particle size is less than 3 μm. The mass of deionized water or ethanol used is 15% of the mass of the catalytic cracking catalyst. The stirring time for the slurry is 30 min at a speed of 150 r / min. -1 The grinding speed is 300 r / min. -1 The grinding time is 60 minutes.

[0057] The slurry obtained above was spray-dried at 600°C for 4 hours and then cured at 550°C for 4 hours. The resulting catalyst had a particle size of 30-95 μm for 60-70 wt% after curing.

[0058] The regenerated and modified catalytic cracking catalyst enters the riser reactor. Under a reaction temperature of 370℃, the coking propylene undergoes a thermal cracking reaction, converting large molecular weight sulfides that are difficult to remove into small molecular weight sulfides. Gas chromatography analysis shows that the loss rate of coking propylene is 1.5%.

[0059] Preparation method of integrated desulfurization catalyst:

[0060] Catalyst core preparation: 824g of HY molecular sieve, 194g of metatitanic acid, and 25g of polyvinyl alcohol were weighed and mixed evenly to form a solid material; 19g of nitric acid was weighed and added to water and stirred evenly to prepare a solution; the evenly mixed solid material was placed in a ball rolling machine, and the nitric acid solution was sprayed into the material in the ball rolling machine. The ball was rolled and shaped to obtain small balls with a diameter of 2mm; the small balls were dried at 120℃ for 6h and calcined at 400℃ for 5h to obtain catalyst core support A.

[0061] Weigh out 72g of potassium nitrate, 64g of gallium nitrate, and 52g of lanthanum nitrate and dissolve them in water to prepare a solution. Add the catalyst core support A to the solution and impregnate for 3 hours. Dry the impregnated support at 130℃ for 4 hours and calcine it at 490℃ for 5 hours to obtain the catalyst core A.

[0062] Catalyst shell coating:

[0063] 6g of HZSM-23 support was weighed and dispersed in 124mL of methanol. After stirring and sonication, a homogeneous mixture I was obtained. 2g of zinc nitrate hexahydrate was weighed and added to mixture I. The mixture was stirred at 25℃ for 30 minutes until fully dissolved, yielding mixture II. 11g of methylimidazole was added to mixture II, and the mixture was stirred at 25℃ for 3 hours to obtain a composite. The core of catalyst A obtained above was added to a coating machine and coated with the composite obtained above, controlling the coating thickness to be approximately 1mm. The coated pellets were dried at 100℃ for 4 hours. After drying, they were calcined at 650℃ for 3 hours under a nitrogen atmosphere to obtain coking propylene carbonyl sulfur hydrolysis catalyst A.

[0064] Catalyst application methods:

[0065] Evaluation conditions for integrated desulfurization catalysts: space velocity of 3000 h⁻¹ -1 The reaction temperature was 50℃, and the reaction pressure was atmospheric pressure. The raw material was coking propylene, with COS and H2S contents of 6ppm and 2ppm, respectively. The COS and H2S contents in the raw material and the purified gas were measured to be 0.3ppm and 0.5ppm, respectively, using a speciation sulfur analyzer.

[0066] After partial removal of carbonyl sulfur and hydrogen sulfide by an integrated desulfurization catalyst, the sulfur content in coking propylene is further reduced by adsorption using a combination of ZnO and activated carbon adsorbents. The mass ratio of ZnO to activated carbon is 1:6, and the space velocity of coking propylene is 1000 h⁻¹. -1 Total sulfur was not detected after adsorption.

[0067] After purification through the steps described above, the coking propylene enters the carbonyl synthesis unit, which comprises two carbonyl synthesis reactors connected in series: a low-pressure carbonyl synthesis reaction is carried out in the presence of a rhodium-Parker catalyst, with stirring, an operating temperature of 110°C, and an operating pressure of 1.8 MPa. The reaction liquid is separated by a catalyst to obtain n- / isobutyraldehyde, and the catalyst solution is recycled back to the reaction system to continue participating in the reaction. The n- / isobutyraldehyde then enters the aldehyde distillation unit to remove light components, and is further separated by an isomerization tower to obtain n-butyraldehyde and isobutyraldehyde, with isobutyraldehyde being produced as the product. The separated n-butyraldehyde is sent to a condensation reactor and an alcohol-aldehyde condensation recycling tower connected in series. In the condensation unit, a condensation reaction occurs in the presence of an alkaline catalyst, with stirring, an operating temperature of 120°C, and an operating pressure of 0.40 MPa, to produce octenal and water. After passing through a chromatography column, the octenal reacts with hydrogen in a gas-phase hydrogenation reactor containing a catalyst, under operating conditions of 0.45 MPa and 200°C, to directly hydrogenate crude octanol. Crude octanol is then fed into a liquid-phase hydrogenation reactor for further hydrogenation at a pressure of 2.60 MPa and a temperature of 85 °C. Following this, it is distilled to obtain the product octanol. Butyraldehyde can be further hydrogenated and distilled to obtain butanol.

[0068] Example 2

[0069] Regeneration and modification of spent catalytic cracking catalysts:

[0070] 1. The coking process of spent catalytic cracking catalyst includes two coking steps to better achieve coking and remove any residual organic matter within the catalyst pores.

[0071] (1) First coking, slightly positive pressure, reactor inlet temperature 560℃, nitrogen space velocity 1100h -1 air velocity 100 h -1 The charring time is 3 hours.

[0072] (2) Second coking, slightly positive pressure, reactor inlet temperature 575℃, nitrogen space velocity 1100h -1 air speed 300 h -1 The charring time is 5 hours.

[0073] 2. Preparation of CuY molecular sieve: First, 800g of NaY molecular sieve was subjected to ion exchange with 0.1mol / L nitric acid aqueous solution for 3h; then, the obtained HY molecular sieve was subjected to ion exchange with 0.1mol / L copper nitrate aqueous solution for 4h. After filtration and drying, CuY molecular sieve was finally obtained.

[0074] 3. Modification and regeneration of the catalytic cracking catalyst: The catalytic cracking catalyst that has undergone primary and secondary coking and the CuY molecular sieve prepared in step 2 are mixed at a mass ratio of 4.5:1. Deionized water is added and stirred to prepare a slurry. The slurry is then ground in a grinder until the solid particle size is less than 3 μm. The mass of deionized water or ethanol used is 15% of the mass of the catalytic cracking catalyst. The stirring time for the slurry is 30 min at a speed of 150 r / min. -1 The grinding speed is 300 r / min. -1 The grinding time is 60 minutes.

[0075] The slurry obtained above was spray-dried at 600°C for 4 hours and then cured at 550°C for 4 hours. The resulting catalyst had a particle size of 30-95 μm for 60-70 wt% after curing.

[0076] The regenerated and modified catalytic cracking catalyst enters the riser reactor. Under a reaction temperature of 400℃, the coking propylene undergoes a thermal cracking reaction, converting large molecular weight sulfides that are difficult to remove into small molecular weight sulfides. Gas chromatography analysis shows that the loss rate of coking propylene is 2.3%.

[0077] Preparation method of integrated desulfurization catalyst:

[0078] Catalyst core preparation: 989g of HY molecular sieve, 256g of metatitanic acid, and 24g of polyvinyl alcohol were weighed and mixed evenly to form a solid material; 21g of nitric acid was weighed and added to water and stirred evenly to prepare a solution; the evenly mixed solid material was placed in a ball rolling machine, and the nitric acid solution was sprayed into the material in the ball rolling machine. The ball was rolled and shaped to obtain small balls with a diameter of 2mm; the small balls were dried at 120℃ for 6h and calcined at 400℃ for 5h to obtain catalyst core support A.

[0079] Weigh out 89g of potassium nitrate, 74g of gallium nitrate, and 65g of lanthanum nitrate and dissolve them in water to prepare a solution. Add the catalyst core support A to the solution and impregnate for 3 hours. Dry the impregnated support at 130℃ for 4 hours and calcine it at 490℃ for 5 hours to obtain the catalyst core B.

[0080] Catalyst shell coating:

[0081] 7g of HZSM-23 support was weighed and dispersed in 163mL of methanol. After stirring and sonication, a homogeneous mixture I was obtained. 2g of zinc nitrate hexahydrate was weighed and added to mixture I. The mixture was stirred at 25℃ for 30 minutes until fully dissolved, yielding mixture II. 12g of methylimidazole was added to mixture II, and the mixture was stirred at 25℃ for 3 hours to obtain a composite. The core of catalyst A obtained above was added to a coating machine and coated with the composite obtained above, controlling the coating thickness to be approximately 1mm. The coated pellets were dried at 100℃ for 4 hours. After drying, they were calcined at 650℃ for 3 hours under a nitrogen atmosphere to obtain coking propylene carbonyl sulfur hydrolysis catalyst B.

[0082] Catalyst application methods:

[0083] Evaluation conditions for the integrated desulfurization catalyst: space velocity of 2000 h⁻¹, reaction temperature of 40℃, and reaction pressure of atmospheric pressure. The reactant was coking propylene, with COS and H₂S contents of 6 ppm and 2 ppm, respectively. The COS and H₂S contents in the reactant and purified gas were measured to be 0.6 ppm and 0.5 ppm, respectively, using a speciation sulfur analyzer.

[0084] After partial removal of carbonyl sulfur and hydrogen sulfide by an integrated desulfurization catalyst, the sulfur content in coking propylene is further reduced by adsorption using a combination of ZnO and activated carbon adsorbents. The mass ratio of ZnO to activated carbon is 1:3, and the space velocity of coking propylene is 1900 h⁻¹. -1 Total sulfur was not detected after adsorption.

[0085] After purification through the steps described above, the coking propylene enters the carbonyl synthesis unit, which comprises two carbonyl synthesis reactors connected in series: a low-pressure carbonyl synthesis reaction is carried out in the presence of a rhodium-Parker catalyst, with stirring, an operating temperature of 100°C, and an operating pressure of 1.8 MPa. The reaction liquid is separated by a catalyst to obtain n- / isobutyraldehyde, and the catalyst solution is recycled back to the reaction system to continue participating in the reaction. The n- / isobutyraldehyde then enters the aldehyde distillation unit to remove light components, and is further separated by an isomerization tower to obtain n-butyraldehyde and isobutyraldehyde, with isobutyraldehyde being produced as the product. The separated n-butyraldehyde is sent to a condensation reactor and an alcohol-aldehyde condensation recycling tower connected in series. In the condensation unit, a condensation reaction occurs in the presence of an alkaline catalyst, with stirring, an operating temperature of 120°C, and an operating pressure of 0.40 MPa, to produce octenal and water. After passing through a chromatography column, the octenal reacts with hydrogen in a gas-phase hydrogenation reactor containing a catalyst, under operating conditions of 0.45 MPa and 200°C, to directly hydrogenate crude octanol. Crude octanol is then fed into a liquid-phase hydrogenation reactor for further hydrogenation at a pressure of 2.60 MPa and a temperature of 85 °C. Following this, it is distilled to obtain the product octanol. Butyraldehyde can be further hydrogenated and distilled to obtain butanol.

[0086] Comparative Example 1

[0087] Except for the use of a fresh catalytic cracking catalyst in the catalytic pyrolysis, the process was the same as in Example 1. Gas chromatography analysis after catalytic pyrolysis showed a propylene loss rate of 7.5%.

[0088] Comparative Example 2

[0089] Except for the use of a known commercial carbonyl sulfur hydrolysant for further desulfurization of the coking propylene after catalytic cracking, instead of a self-made integrated desulfurizing agent, the rest is the same as in Example 2.

[0090] Evaluation conditions for commercial carbonyl sulfur hydrolysants: space velocity of 2000 h⁻¹ -1 The reaction temperature was 40℃, and the reaction pressure was atmospheric pressure. The raw material was coking propylene, with COS and H2S contents of 6ppm and 2ppm, respectively. The COS and H2S contents in the raw material and the purified gas were measured to be 0.6ppm and 8ppm, respectively, using a speciation sulfur analyzer.

[0091] After partial removal of carbonyl sulfur and hydrogen sulfide by an integrated desulfurization catalyst, the sulfur content in coking propylene is further reduced by adsorption using a combination of ZnO and activated carbon adsorbents. The mass ratio of ZnO to activated carbon is 1:3, and the space velocity of the coking propylene is 1900 h⁻¹. The total sulfur content after adsorption is 3 ppm.

[0092] Obviously, the above embodiments are merely illustrative examples for clear explanation and are not intended to limit the implementation. Those skilled in the art will recognize that other variations or modifications can be made based on the above description. It is neither necessary nor possible to exhaustively list all possible implementations here. However, obvious variations or modifications derived therefrom are still within the scope of protection of this invention.

Claims

1. A method for preparing an integrated desulfurization catalyst used in the process of producing butanol and octanol from coking propylene, characterized in that, Includes the following steps, s1. Kernel preparation: s11. Mix the molecular sieve, titanium dioxide precursor, and additives evenly to form a solid material; s12. Prepare solution A from the adhesive; s13. Spherical Spinning: The solution A is sprayed onto the solid material to obtain a spherical carrier; s14. Impregnation: Prepare solution B by preparing the precursors of the active components potassium oxide, gallium oxide and lanthanum oxide, and impregnate the carrier from step s13 in solution B for a period of time; s15. Drying: Dry the carrier after impregnation in step s14; s16. Calcination: The support dried in step s15 is calcined to obtain an integrated desulfurization catalyst core; s2. Preparation of the outer shell: s21. Molecular sieves are dispersed in a solvent to prepare suspension I; s22. Add the zinc source to the suspension I to prepare suspension II; s23. Add a heterocyclic organic compound containing C and N elements to the suspension II to prepare a suspension of the complex; s24. Apply a suspension of the composite material to the surface of the integrated desulfurization catalyst core; s25. The integrated desulfurization catalyst core coated in step s24 is dried and calcined to obtain the integrated desulfurization catalyst.

2. The preparation method according to claim 1, characterized in that, In the core preparation process, the calculation principle for the amount of titanium oxide precursor and active component precursor is: calculated based on the weight parts of oxide; according to the calculation principle, the required weight parts of molecular sieve and oxide are: 52-80 parts of molecular sieve, 20-35 parts of titanium oxide, 3-7 parts of potassium oxide, 1-3 parts of gallium oxide, and 2-4 parts of lanthanum oxide.

3. The preparation method according to claim 1, characterized in that, The molecular sieves used in the core preparation process are any one or more of HY, HMCM-22, and HZSM-5.

4. The preparation method according to claim 1, characterized in that, The binder used in the core preparation process is any one of acetic acid, nitric acid, or citric acid.

5. The preparation method according to claim 1, characterized in that, The solvents used in the preparation of the outer shell include any one or more of methanol, water, or N,N-dimethylformamide.

6. The preparation method according to claim 1, characterized in that, The heterocyclic organic compounds containing C and N elements mentioned in the shell preparation process include any one or more of 2-methylimidazolium, imidazolium, pyridine, or benzopyridine.

7. The preparation method according to claim 1, characterized in that, During the preparation of the outer shell, the ratio of the mass of the molecular sieve to the volume of the solvent is 1:10-1:

50.

8. An integrated desulfurization catalyst prepared according to claim 1 and used in the process of preparing butanol and octanol from coking propylene, characterized in that, The catalyst has a core-shell structure, comprising a core and a shell, wherein: The core includes a carrier and an active component; The carrier includes aluminum oxide, silicon dioxide and titanium oxide, and the active components include potassium oxide, gallium oxide and lanthanum oxide; The outer shell is a C and N doped composite, which includes zinc oxide, aluminum oxide and silicon dioxide.

9. A purification method for deep desulfurization of coking propylene using the integrated desulfurization catalyst of claim 8.