Application of an oxygen carrier for ethane chemical chain production of ethylene

Abstract

The present invention discloses the preparation and application of an oxygen carrier in the ethane chemical chain to ethylene production. The oxygen carrier is a monolithic Fe2O3 / LaNiO3 / Al2O3 oxygen carrier with a honeycomb structure and a pore size of 0.5 to 10 mm. The monolithic oxygen carrier has a unique structure with a large pore size and active components dispersed on its surface, making it very suitable as an oxygen carrier for the rapid conversion of ethane to ethylene. First, the honeycomb carrier is pretreated to load a certain amount of Al2O3, and then the perovskite oxide LaNiO3 is loaded onto the carrier by a sol impregnation method. Then, iron oxide is loaded onto the above-mentioned carrier by an impregnation method to form a monolithic Fe2O3 / LaNiO3 / Al2O3 oxygen carrier with a honeycomb structure. The oxygen carrier of the present invention can be used in the ethane chemical chain to ethylene technology. The oxygen carrier has the advantages of large pore size, small pressure drop, and high dispersion of active components, and can improve the ethane conversion rate and ethylene selectivity.

Description

Technical Field

[0001] The invention relates to the preparation and application of an oxygen carrier in ethane chemical chain production of ethylene, belonging to the oxygen carrier technology in the field of ethane chemical chain production of ethylene. Background Art

[0002] The ethylene industry is a vital component of the petrochemical industry and a key indicator of a country's petrochemical development. Currently, steam cracking is the mainstream process for ethylene production, with coal-to-ethylene technology serving as an important supplement. However, the former suffers from limitations such as high energy consumption and an irrational feedstock mix, while the latter is constrained by environmental requirements, oil prices, and other factors. These limitations of existing technologies have promoted the development of ethylene production technology. In recent years, researchers have conducted extensive research in areas such as utilizing inexpensive feedstocks, catalyst innovation, and developing low-energy, short-process technologies. They have explored various new ethylene production technologies and achieved significant progress.

[0003] In 1983, German scientists Richter and Knoche first proposed the concept of chemical looping combustion (CLC). This combustion technology differs significantly from conventional combustion techniques in that it utilizes oxygen atoms from an oxygen carrier to complete the fuel combustion process, rather than directly using oxygen molecules from air. The combustion products (primarily CO2 and water vapor) are not diluted by nitrogen in the air and remain extremely concentrated. Pure CO2 can be obtained through simple condensation and dehydration, enabling simple and energy-efficient CO2 separation and capture. Ethane chemical looping oxidative dehydrogenation (CL-ODH) is a technology developed based on CLC. Because the reaction process does not require oxygen or inert gas dilution, it significantly improves the safety environment and reduces process investment and operating costs. The CL-ODH process consists of two steps: first, ethane is oxidized by an oxygen carrier to produce ethylene and water, while the oxygen carrier is simultaneously reduced by ethane. Then, air is introduced to oxidize the oxygen carrier and release heat, completing the cycle. Typically, the oxygen carrier in this technology undergoes multiple redox cycles. This technology has the characteristics of low-cost oxygen carrier, self-heating and continuous operation of the process, and breaking the thermodynamic equilibrium of alkane dehydrogenation. It can greatly improve the yield of olefins, and the process flow is short, saving investment and operating costs, so it has good development and application prospects.

[0004] At present, the ethane chemical chain oxidative dehydrogenation technology to produce ethylene has not been industrially applied. The main reason is that the oxygen carrier still has problems such as small pore size, limited oxygen carrying rate and low activity. The simulation results of Haribal et al. show that the use of ethane CL-ODH is expected to reduce energy consumption and carbon dioxide emissions by 82%. The in-situ oxidation of hydrogen can also reduce the volume flow rate of gas products by about 40%, significantly reducing the compression and separation load. Although the simulation results show that ethane CL-ODH has potential advantages, the key to this technology is that the redox oxygen carrier should have good activity, selectivity and stability. Yusuf S. et al. investigated manganese magnesium and manganese silicon mixed oxides with NaWO4 as a promoter at 850 ° C, and the ethylene yield was as high as 68%. Elvadawi A. et al. investigated a series of VO x -MoO x The γ-Al2O3 oxygen carrier can achieve 55%-85% ethylene selectivity after multiple reaction-regeneration cycles at temperatures between 500 and 650°C, but ethane conversion is relatively low. Currently, research both domestically and internationally focuses on oxygen carrier screening and performance optimization through simulations and laboratory experiments. While this technology holds considerable promise, further progress towards industrial application is only possible after resolving the issue of poor oxygen carrier performance.

[0005] The reaction of an oxygen carrier with ethane and water vapor is a rapid mass transfer process. Therefore, the design of the oxygen carrier should take into account its structure and the dispersion of the active components. As is well known, monolithic catalysts (including honeycomb monoliths, foam structures, and open cross-flow structures) have been widely used in recent years due to their unique structure. For example, they are used in the selective catalytic reduction of NO with NH3, the catalytic combustion of methane, and the catalytic combustion of benzene. However, there have been no reports of their use in the chemical chaining of ethane to ethylene. However, monolithic catalysts, with their large pore size and the unique structure of dispersed active components on the surface, are well-suited as oxygen carriers for this process. Summary of the Invention

[0006] In view of the shortcomings of the existing technology, the present invention provides an oxygen carrier for ethane chemical chain production of ethylene technology and its preparation method and application.

[0007] The oxygen carrier described in the present invention is prepared by using a honeycomb carrier. First, the honeycomb carrier is immersed in a certain concentration of nitric acid for pretreatment, then taken out and dried and immersed in a certain concentration of aluminum sol. After drying and calcining, a honeycomb carrier loaded with Al2O3 is obtained. After the honeycomb carrier is loaded with Al2O3, the loading amount of the oxide in the subsequent process can be increased.

[0008] The oxygen carrier described in the present invention is prepared by using a honeycomb carrier, and the perovskite oxide LaNiO3 is loaded onto the Al2O3 / honeycomb carrier by a sol impregnation method, and then iron oxide is loaded onto the carrier by an impregnation method to form a Fe2O3 / LaNiO3 / Al2O3 integral oxygen carrier with a honeycomb structure.

[0009] In the application of the present invention, the reaction temperature of the composite metal oxide oxygen carrier with a perovskite structure in the fuel reactor is 600-1000° C., the reaction temperature in the oxidation reactor is 600-1000° C., and the reaction pressure is 0.1-10 MPa.

[0010] The honeycomb carrier of the present invention adopts 400CPSI, the carrier is 10-30mm long, preferably 15-20mm long, the diameter is 3mm-15mm, preferably 5-8mm, and the honeycomb wall thickness is 0.04mm.

[0011] The LaNiO3 sol of the present invention is prepared by a citric acid complexation method. The specific process is as follows: lanthanum nitrate and nickel nitrate are used as precursors, citric acid or ethylene glycol is used as a complexing agent, a solution is prepared and mixed and stirred evenly, and then water is evaporated to convert the solution into a sol. Then, a pretreated metal support is heated to 400-800°C, preferably 500-600°C, and quickly inserted into the sol. After 1-10 minutes, it is slowly removed, preferably 1-3 minutes, and dried at room temperature for 2-24 hours, preferably 6-12 hours, and then dried at 80-120°C overnight, preferably 100-120°C. The dried sample is placed in a muffle furnace and calcined at 600-1000°C for 2-10 hours, preferably 800-900°C for 3-5 hours.

[0012] The loaded Fe2O3 of the present invention is prepared by an impregnation method. The specific process is as follows: ferric nitrate solution and ammonia water are dripped into distilled water in parallel, and the solution is stirred rapidly to control the pH value of the solution to 8-11, preferably 9-10. After the titration, the solution is aged for 2-12 hours, preferably 4-8 hours, filtered, washed with water, and stirred in a water bath at 30-80°C for 1-8 hours, preferably in a water bath at 50-80°C for 2-4 hours. The prepared LaNiO3 loaded on the honeycomb carrier is used as a carrier and impregnated into the solution. After 1-10 minutes, the carrier is slowly removed, preferably 3-5 minutes, dried at room temperature for 2-24 hours, preferably 6-12 hours, dried overnight at 80-120°C, preferably 100-120°C, and the dried sample is placed in a muffle furnace and calcined at 700-1000°C for 2-6 hours, preferably 800-900°C for 3-4 hours to obtain a Fe2O3 / LaNiO3 / Al2O3 monolithic oxygen carrier with a honeycomb structure.

[0013] In the oxygen carrier preparation method of the present invention, the complexing agent can be citric acid or ethylene glycol, and the molar ratio of the complexing agent to the metal ion is 1:1 to 5:1, preferably 1:1 to 2:1. The solution is prepared and stirred at 30 to 90°C, preferably 50 to 80°C. The stirring rate is 100 to 500 rpm, preferably 300 to 400 rpm. The stirring time is 3 to 8 hours, preferably 4 to 6 hours. The drying temperature is 60 to 200°C, preferably 80 to 150°C. The drying time is 1 to 36 hours, preferably 8 to 24 hours. The roasting temperature is 400 to 1000°C, and the roasting time is 2 to 15 hours, preferably roasting at 700 to 900°C for 3 to 8 hours.

[0014] The loading amount of the oxygen carrier on the honeycomb carrier in the present invention is 0.3-2 g / cm 3 , preferably 0.8 to 1.2 g / cm 3 , the mass content of Fe2O3 is 1 to 50%, preferably 10 to 30%.

[0015] Compared with the prior art, the present invention has the following advantages:

[0016] 1. The oxygen carrier has a rich macroporous structure, which is conducive to mass transfer. The reaction between the oxygen carrier and air is a strong exothermic reaction, and the macroporous structure is conducive to heat transfer.

[0017] 2. The oxygen carrier is easy to load and the pressure drop is low.

[0018] 3. The active components are highly dispersed on the carrier surface and the oxygen carrier activity is high. DETAILED DESCRIPTION

[0019] The process and effects of the method of the present invention are further illustrated below with reference to the examples.

[0020] Example 1

[0021] (1) A monolithic oxygen carrier was prepared using a 400 CPSI FeCrAl honeycomb substrate with a length of 15 mm, a diameter of 10 mm, and a honeycomb wall thickness of 1.14 nm. The honeycomb substrate was pretreated with nitric acid. Using pseudo-boehmite and nitric acid as raw materials, the pseudo-boehmite was first mixed evenly with a certain volume of distilled water. A certain amount of nitric acid solution was added while stirring, and stirring was continued for 2 h to obtain an aluminum sol. The treated honeycomb substrate was immersed in the aluminum sol and removed after 5 min. The excess liquid was blown off with an ear bulb. The substrate was then dried at 120°C overnight and calcined in a muffle furnace at 800°C for 4 h to obtain an Al2O3-loaded honeycomb substrate.

[0022] (2) Take 23g of Ni(NO3)2·6H2O and place it in a 500mL beaker. Add 100mL of distilled water to dissolve it. Take 34.3g of La(NO3)3·6H2O and place it in a beaker filled with 100mL of distilled water. Stir until it is completely dissolved. Then add the lanthanum nitrate solution dropwise to the nickel nitrate solution while stirring. The molar ratio of Ni to La is 1 / 1. Then place the beaker in an 80℃ water bath and stir at 400rpm. Take 40g of citric acid, with a molar ratio of citric acid to total metal ions of 1.2:1, place it in a 100mL beaker and stir until it is completely dissolved. After the above mixed solution is stirred for 30 minutes, slowly add the citric acid solution while stirring. After stirring for 4 hours, the solution loses some water and becomes an opaque sol. The Al2O3-loaded honeycomb carrier is then heated to 500°C and quickly inserted into the above sol. After 1 minute, it is slowly taken out and the excess sol is blown away with an ear bulb. The sample is dried at room temperature for 12 hours and dried in a drying oven at 110°C overnight. The dried sample is placed in a muffle furnace and calcined at 800°C for 4 hours to obtain a LaNiO3 / Al2O3 honeycomb carrier.

[0023] (3) Add a certain concentration of ferric nitrate solution and ammonia water to distilled water in parallel, stir rapidly, and control the pH value of the solution to 10. After the titration, age for 4 hours, filter, wash with water, and stir in a 60°C water bath for 4 hours to form a uniform solution. Then, immerse the LaNiO3 / Al2O3 honeycomb carrier in the above solution, slowly take it out after 10 minutes, blow off the excess solution with an ear bulb, dry it at room temperature for 12 hours, dry it in a drying oven at 110°C overnight, place the dried sample in a muffle furnace, and calcine it at 800°C for 4 hours to obtain a Fe2O3 / LaNiO3 / Al2O3 honeycomb oxygen carrier.

[0024] Example 2

[0025] The processes of steps (1) and (2) are the same as those in Example 1.

[0026] (3) A certain concentration of ferric nitrate solution and ammonia water were dripped into distilled water in parallel, stirred rapidly, and the pH value of the solution was controlled to be 9. After the titration, the solution was aged for 4 hours, filtered, washed with water, and stirred in a 60°C water bath for 4 hours to obtain a uniformly mixed solution. The LaNiO3 / Al2O3 honeycomb carrier was immersed in the above solution, slowly taken out after 10 minutes, and the excess solution was blown off with an ear bulb. The sample was dried at room temperature for 12 hours and dried in a drying oven at 110°C overnight. The dried sample was placed in a muffle furnace and calcined at 800°C for 4 hours to obtain a Fe2O3 / LaNiO3 oxygen carrier with a honeycomb structure.

[0027] Example 3

[0028] The processes of steps (1) and (2) are the same as those in Example 1.

[0029] (3) Add ferric nitrate solution and ammonia water to distilled water in parallel and stir rapidly to control the pH value of the solution to 10. After the titration, age for 4 hours, filter, wash with water, and stir in a 60°C water bath for 4 hours to form a uniform solution. Then, immerse the LaNiO3 / Al2O3 honeycomb carrier in the above solution, slowly take it out after 10 minutes, blow off the excess solution with an ear bulb, dry it at room temperature for 12 hours, dry it in a drying oven at 110°C overnight, place the dried sample in a muffle furnace, and calcine it at 700°C for 3 hours to obtain a Fe2O3 / LaNiO3 / Al2O3 honeycomb oxygen carrier.

[0030] Example 4

[0031] The processes of steps (1) and (2) are the same as those in Example 1.

[0032] (3) Add ferric nitrate solution and ammonia water to distilled water in parallel and stir rapidly to control the pH value of the solution to 10. After the titration, age for 4 hours, filter, wash with water, and stir in a 60°C water bath for 4 hours to form a uniform solution. Then, immerse the LaNiO3 / Al2O3 honeycomb carrier in the above solution, slowly take it out after 10 minutes, blow off the excess solution with an ear bulb, dry it at room temperature for 12 hours, dry it in a drying oven at 110°C overnight, place the dried sample in a muffle furnace, and calcine it at 900°C for 8 hours to obtain a Fe2O3 / LaNiO3 / Al2O3 honeycomb oxygen carrier.

[0033] Example 5

[0034] The processes of steps (1) and (2) are the same as those in Example 1.

[0035] (3) Add ferric nitrate solution and ammonia water to distilled water in parallel and stir rapidly to control the pH value of the solution to 10. After the titration, age for 4 hours, filter, wash with water, and stir in a 50°C water bath for 2 hours to form a uniform solution. Then, immerse the LaNiO3 / Al2O3 honeycomb carrier in the above solution, slowly take it out after 10 minutes, blow off the excess solution with an ear bulb, dry it at room temperature for 12 hours, dry it in a drying oven at 110°C overnight, place the dried sample in a muffle furnace, and calcine it at 900°C for 8 hours to obtain a Fe2O3 / LaNiO3 / Al2O3 honeycomb oxygen carrier.

[0036] Example 6

[0037] The processes of steps (1) and (2) are the same as those in Example 1.

[0038] (3) Add ferric nitrate solution and ammonia water to distilled water in parallel and stir rapidly to control the pH value of the solution to 10. After the titration, age for 4 hours, filter, wash with water, and stir in an 80°C water bath for 4 hours to form a uniform solution. Then, immerse the LaNiO3 / Al2O3 honeycomb carrier in the above solution, slowly take it out after 10 minutes, blow off the excess solution with an ear bulb, dry it at room temperature for 12 hours, dry it in a drying oven at 110°C overnight, place the dried sample in a muffle furnace, and calcine it at 900°C for 8 hours to obtain a Fe2O3 / LaNiO3 / Al2O3 honeycomb oxygen carrier.

[0039] Example 7

[0040] The process of steps (1) and (3) is the same as that of Example 1.

[0041] (2) Take 23g of Ni(NO3)2·6H2O and place it in a 500mL beaker. Add 100mL of distilled water to dissolve it. Take 34.3g of La(NO3)3·6H2O and place it in a beaker filled with 100mL of distilled water. Stir until it is completely dissolved. Then add the lanthanum nitrate solution dropwise to the nickel nitrate solution while stirring. The molar ratio of Ni to La is 1 / 1. Then place the beaker in an 80℃ water bath and stir at 400rpm. Take 40g of citric acid, with a molar ratio of citric acid to the total amount of metal ions of 1:1, place it in a 100mL beaker and stir until it is completely dissolved. After the above mixed solution is stirred for 30 minutes, slowly add the citric acid solution while stirring. After stirring for 4 hours, the solution loses some water and becomes an opaque sol. The Al2O3-loaded honeycomb carrier is then heated to 500°C and quickly inserted into the above sol. After 1 minute, it is slowly taken out and the excess sol is blown away with an ear bulb. The sample is dried at room temperature for 12 hours and dried in a drying oven at 110°C overnight. The dried sample is placed in a muffle furnace and calcined at 800°C for 4 hours to obtain a LaNiO3 / Al2O3 honeycomb carrier.

[0042] Example 8

[0043] The process of steps (1) and (3) is the same as that of Example 1.

[0044] (2) Take 23g of Ni(NO3)2·6H2O and place it in a 500mL beaker. Add 100mL of distilled water to dissolve it. Take 34.3g of La(NO3)3·6H2O and place it in a beaker filled with 100mL of distilled water. Stir until it is completely dissolved. Then add the lanthanum nitrate solution dropwise to the nickel nitrate solution while stirring. The molar ratio of Ni to La is 1 / 1. Then place the beaker in an 80℃ water bath and stir at 400rpm. Take 40g of citric acid, with a molar ratio of citric acid to total metal ions of 2:1, place it in a 100mL beaker and stir until it is completely dissolved. After the above mixed solution is stirred for 30 minutes, slowly add the citric acid solution while stirring. After stirring for 4 hours, the solution loses some water and becomes an opaque sol. The Al2O3-loaded honeycomb carrier is then heated to 500°C and quickly inserted into the above sol. After 1 minute, it is slowly taken out and the excess sol is blown away with an ear bulb. The sample is dried at room temperature for 12 hours and dried in a drying oven at 110°C overnight. The dried sample is placed in a muffle furnace and calcined at 800°C for 4 hours to obtain a LaNiO3 / Al2O3 honeycomb carrier.

[0045] Example 9

[0046] The process of steps (1) and (3) is the same as that of Example 1.

[0047] (2) Take 23g of Ni(NO3)2·6H2O and place it in a 500mL beaker. Add 100mL of distilled water to dissolve it. Take 34.3g of La(NO3)3·6H2O and place it in a beaker filled with 100mL of distilled water. Stir until it is completely dissolved. Then add the lanthanum nitrate solution dropwise to the nickel nitrate solution while stirring. The molar ratio of Ni to La is 1 / 1. Then place the beaker in an 80℃ water bath and stir at 400rpm. Take 40g of citric acid, with a molar ratio of citric acid to total metal ions of 2:1, place it in a 100mL beaker and stir until it is completely dissolved. After the above mixed solution is stirred for 30 minutes, slowly add the citric acid solution while stirring. After stirring for 4 hours, the solution loses some water and becomes an opaque sol. The Al2O3-loaded honeycomb carrier is then heated to 500°C and quickly inserted into the above sol. After 1 minute, it is slowly taken out and the excess sol is blown away with an ear bulb. The sample is dried at room temperature for 12 hours and dried in a drying oven at 110°C overnight. The dried sample is placed in a muffle furnace and calcined at 700°C for 8 hours to obtain a LaNiO3 / Al2O3 honeycomb carrier.

[0048] Comparative Example

[0049] Fe2O3 / LaNiO3 powder oxygen carrier was prepared by citric acid complexation method, and the calcination conditions and performance test conditions were the same as those in Example 1.

[0050] Example 10

[0051] The performance evaluation of the oxygen carrier prepared in the above-mentioned embodiment and comparative example is carried out as follows. The above-mentioned oxygen carrier obtained is sieved, and 0.4g of oxygen carrier with a particle size of 40-60 mesh is taken and performance tested on a fixed-bed quartz tube reactor. The quartz tube size is φ8×2, and the raw gas composition is: 10% C2H6, 90% N2. The sample is heated from room temperature to 750°C under nitrogen protection, and then the raw gas is introduced to react, with a raw gas flow rate of 50ml / L. After reacting for 1-5 minutes, a nitrogen purge is introduced for 10 minutes, and then air is switched to be oxidized, with an air flow rate of 30ml / L. After 10 minutes, a nitrogen purge is introduced to complete an oxidation-reduction cycle. The results are analyzed by gas chromatography online, TCD detection, 5A molecular sieve column and Porapak Q column.

[0052] The performance evaluation results are shown in Table 1.

[0053] Table 1 Reaction performance of oxygen carriers

[0054]

[0055]

Claims

1. An application of an oxygen carrier for ethane chemical chain production of ethylene, characterized by: The application is ethane chemical chaining to ethylene: The loading amount of oxygen carrier on the honeycomb carrier is 0.3~2g / cm 3 , wherein the mass content of Fe2O3 is 1 to 50%, and the preparation method of the oxygen carrier comprises the following steps: ① First, the honeycomb support is immersed in a certain concentration of nitric acid for pretreatment, then taken out and dried and immersed in a certain concentration of aluminum sol. After drying and calcining, a honeycomb support loaded with Al2O3 is obtained. After the honeycomb support is loaded with Al2O3, the loading amount of oxides in the subsequent process can be increased; ② Secondly, the perovskite oxide LaNiO3 is loaded onto the Al2O3 / honeycomb carrier by the same sol impregnation method, and then the iron oxide is loaded onto the carrier by the impregnation method to form a Fe2O3 / LaNiO3 / Al2O3 oxygen carrier with a honeycomb structure.

2. The use according to claim 1, characterized in that: The interior of the honeycomb carrier is composed of many through-going honeycomb-shaped channels. These honeycomb units are divided by thin lattice-shaped partitions. The carrier is 10 to 30 mm long, 3 to 15 mm in diameter, and has a honeycomb wall thickness of 0.04 mm.

3. The use according to claim 1, characterized in that: In step ①, the pretreated metal support is heated to 400-800°C, quickly inserted into the above sol, slowly removed after 1-10 minutes, dried at room temperature for 2-24 hours, dried at 80-120°C overnight, and the dried sample is placed in a muffle furnace and calcined at 600-1000°C for 2-10 hours.

4. The use according to claim 1, characterized in that: In step ②, the ferric nitrate solution and ammonia water are dripped into distilled water in parallel, stirred rapidly, and the pH value of the solution is controlled to 10. After the titration is completed, it is aged for 2 to 12 hours. The LaNiO3 loaded on the honeycomb carrier prepared above is used as a carrier and immersed in the above solution. After 1 to 10 minutes, it is slowly taken out and dried at room temperature for 2 to 24 hours, dried at 80 to 120°C overnight, and calcined in a muffle furnace at 700 to 1000°C for 2 to 6 hours to obtain a Fe2O3 / LaNiO3 / Al2O3 oxygen carrier with a honeycomb structure.

5. The use according to claim 1, wherein the reaction temperature of the composite metal oxide oxygen carrier having a perovskite structure in the fuel reactor is 600-1000°C, the reaction temperature in the air reactor is 600-1000°C, and the reaction pressure is 0.1-10 MPa.

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