Composite oxygen carrier and preparation method and application thereof

Abstract

The present application relates to carbon capture combustion and composite metal material technical field, disclose a kind of composite oxygen carrier and its preparation method and application.The method includes the following steps: (1) active metal soluble salt solution is activated, and the active metal soluble salt solution obtained after activation, biomass particle template and adhesive are mixed, to obtain mixed solution;(2) the mixed solution is stirred, dried, calcined and screened in turn, to obtain composite oxygen carrier.The composite oxygen carrier has excellent multi-component petrochemical high-calorific value mixed gas reactivity, cycle stability, carbon deposition resistance, and the synthesis method and raw material source are rich and the preparation cost is low.

Description

Technical Field

[0001] This invention relates to the fields of carbon capture and combustion and composite metal materials, specifically to a composite oxygen carrier, its preparation method, and its application. Background Technology

[0002] High-calorific-value mixed gas from petrochemical plants is a common industrial byproduct of the petrochemical industry. Currently, the main method of disposal is combustion into carbon dioxide and water in small-powered heaters, thereby achieving purification. However, heating furnaces of a certain scale for handling high-calorific-value mixed gas from petrochemical plants suffer from low combustion efficiency, severe carbon buildup, and high NO emissions. x High concentration and large fluctuations in tail gas oxygen content are among the technological challenges that make it difficult to handle the complex and ever-changing high-calorific-value petrochemical mixtures. Secondly, high-calorific-value petrochemical mixtures are also a high-quality energy source; the heat released during their conversion and combustion can provide thermal energy and steam for petroleum cracking and other steps in petrochemical processes, improving the technical and economic efficiency of petroleum refining systems.

[0003] In the petrochemical industry, heating furnaces account for approximately 80% of CO2 emissions, making CO2 emission reduction imperative. Chemical looping combustion is a highly efficient flameless and oxygen-free combustion technology that divides conventional combustion into two gentle reduction and oxidation reactions, improving the cascade utilization of chemical energy while achieving low-cost CO2 capture. Due to the uniform, weakly oxidizing reaction environment and lower reaction temperature, NO in the flue gas is significantly reduced. x The release rate is relatively low. In summary, chemical looping combustion can be considered a revolutionary combustion technology. Using high-calorific-value petrochemical mixtures in chemical looping combustion, a new generation of carbon capture technology, offers advantages such as low energy consumption, large-scale CO2 emission reduction, and low NOx emissions. x Combustion characteristics are expected to become an important direction for the development of CCUS technology in petrochemical enterprises.

[0004] However, current chemical looping combustion technology focuses on the combustion conversion of single-component fuels. The preparation and performance of conventional oxygen carriers are difficult to meet the requirements of chemical looping combustion of complex and variable petrochemical high-calorific-value mixtures. Technical problems such as low combustion efficiency, poor combustion stability, low reactivity, and low carbon capture efficiency urgently need to be overcome.

[0005] Therefore, there is an urgent need to develop a composite oxygen carrier, its preparation method, and its application, which can improve combustion efficiency, combustion stability, and reactivity. Summary of the Invention

[0006] The purpose of this invention is to overcome the problems of low combustion efficiency, poor combustion stability, low reactivity, and low carbon capture efficiency of oxygen carriers in the chemical looping combustion of high-calorific-value petrochemical mixed gases in the prior art. This invention provides a composite oxygen carrier, its preparation method, and its application. The composite oxygen carrier described in this invention has excellent reactivity, cycle stability, and anti-carbon deposition performance of multi-component high-calorific-value petrochemical mixed gases, and its synthesis method and raw material sources are abundant and the preparation cost is low.

[0007] To achieve the above objectives, the first aspect of the present invention provides a method for preparing a composite oxygen carrier, the method comprising the following steps:

[0008] (1) Activate the active metal soluble salt solution, and mix the activated active metal soluble salt solution, biomass particle template and adhesive to obtain a mixed solution;

[0009] (2) The mixed solution is stirred, dried, calcined and sieved in sequence to obtain a composite oxygen carrier.

[0010] Preferably, in step (1), the active metal in the active metal soluble salt solution is at least one of copper, nickel, iron and aluminum.

[0011] Preferably, in step (1), the active metal soluble salt in the active metal soluble salt solution is at least one of copper nitrate, nickel nitrate, ferric nitrate, and aluminum nitrate.

[0012] Preferably, in step (1), the concentration of the metal cation in the active metal soluble salt solution is 0.01-1 mol / L.

[0013] Preferably, in step (1), the specific process of activation includes: mixing the active metal soluble salt solution and the activating substance.

[0014] Preferably, the activating substance is at least one of acetic acid, hydrochloric acid, and nitric acid.

[0015] Preferably, the concentration of the activating substance is 0.001-0.01 mol / L.

[0016] Preferably, in step (1), the method further includes preparing the biomass pellet template according to the following steps: drying and pulverizing the biomass pellets.

[0017] Preferably, the drying conditions include: a temperature of 95-120℃ and a time of 5-24h.

[0018] Preferably, the particle size of the biomass pellet template is 0.1-2 mm.

[0019] Preferably, in step (1), the volume ratio of the active metal soluble salt solution to the biomass particle template is 1:(0.1-0.3).

[0020] Preferably, in step (1), the adhesive is polyvinyl alcohol and / or polyacryl alcohol.

[0021] Preferably, the concentration of the adhesive in the mixed solution is 0.001-0.005 mol / L.

[0022] Preferably, in step (2), the stirring conditions include: a temperature of 60-100℃, a stirring rate of 25-100r / min, and a time of 24-48h.

[0023] Preferably, in step (2), the drying conditions include a temperature of 95-120°C and a time of 24-48 hours.

[0024] Preferably, in step (2), the calcination conditions include: a temperature of 950-1100℃ and a time of 24-48h.

[0025] A second aspect of the present invention provides a composite oxygen carrier prepared by the method described above.

[0026] Preferably, the particle size of the composite oxygen carrier is 0.15-1.5 mm.

[0027] The third aspect of the present invention provides the application of the above-mentioned composite oxygen carrier in the chemical looping combustion of high-calorific-value petrochemical mixed gases.

[0028] Through the above technical solution, the biomass particles are dried and activated, resulting in abundant and interconnected pores in the biomass structure. This allows soluble metal salts to more easily penetrate the biomass template and enter the inner layer of the particles, leading to high loading efficiency and a significant increase in loading capacity. Furthermore, during high-temperature calcination, biomass can be removed through air combustion, producing a porous metal oxide composite oxygen carrier that facilitates gas-solid contact. This composite oxygen carrier has a specific surface area that can be increased by 2 to 5 times, exhibiting highly efficient conversion characteristics and carbon capture efficiency in the chemical looping combustion of petrochemical gas. The composite oxygen carrier described in this invention is a porous metal oxide with relatively stable oxygen-carrying capacity, lattice oxygen transport capacity, and structural characteristics in the chemical looping combustion of high-calorific-value mixed gases in high-temperature petrochemical processes, and exhibits strong resistance to breakage. Therefore, the composite oxygen carrier described in this invention, prepared using soluble metal salts, possesses good anti-sintering ability and the ability to oxidize mixed alkane fuels, making it suitable for carbon capture of high-calorific-value gases in petrochemical processes. Attached Figure Description

[0029] Figure 1 This is a scanning electron microscope image of the composite oxygen carrier prepared in Example 1;

[0030] Figure 2 This is a diagram showing the concentration of exhaust gas components in the treatment of mixed fuel gas by the composite oxygen carrier prepared in Example 2.

[0031] Figure 3 This is a graph showing the change in the gas conversion rate of the composite oxygen carriers prepared in Examples 3 and 4 during the treatment of mixed fuel gas. Detailed Implementation

[0032] The following provides a detailed description of specific embodiments of the present invention. It should be understood that the specific embodiments described herein are for illustrative and explanatory purposes only and are not intended to limit the scope of the invention.

[0033] The endpoints and any values ​​of the ranges disclosed herein are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of the various ranges, the endpoint values ​​of the various ranges and individual point values, and individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed herein.

[0034] The preparation method of the composite oxygen carrier of the present invention includes the following steps:

[0035] (1) Activate the active metal soluble salt solution, and mix the activated active metal soluble salt solution, biomass particle template and adhesive to obtain a mixed solution;

[0036] (2) The mixed solution is stirred, dried, calcined and sieved in sequence to obtain a composite oxygen carrier.

[0037] According to the method described in this invention, drying and activation enrich and interconnect the pores of the biomass structure, allowing soluble active metal salts to more easily penetrate the biomass template and enter the inner layer of the particles, resulting in high loading efficiency and a significantly increased loading capacity. Furthermore, pyrolysis of the contained biomass under an inert atmosphere prepares a porous metal oxide composite oxygen carrier that facilitates gas-solid contact, significantly increasing the specific surface area and exhibiting highly efficient conversion characteristics and carbon capture efficiency in the chemical looping combustion of petrochemical gas refining. The oxygen carrier prepared from the soluble active metal salts used in this invention possesses certain anti-sintering capabilities and the ability to oxidize mixed alkane fuels, making it suitable for carbon capture of high-calorific-value gases in petrochemical processes.

[0038] In the method described in this invention, in order to improve the ability of the composite oxygen carrier to oxidize mixed alkane fuel gas, its cycle stability, and its anti-carbon deposition performance, in step (1), the active metal in the active metal soluble salt solution is preferably at least one of copper, nickel, iron, and aluminum, more preferably at least two of copper, nickel, iron, and aluminum. In some embodiments, the active metal is nickel and iron. In other embodiments, the active metal is iron and aluminum. In still other embodiments, the active metal is nickel, iron, and aluminum. In yet another embodiment, the active metal is copper, iron, and aluminum.

[0039] In the method described in this invention, in order to improve the ability of the composite oxygen carrier to oxidize mixed alkane fuel gas and enhance its reactivity, in step (1), the active metal soluble salt solution preferably contains at least one of copper nitrate, nickel nitrate, ferric nitrate, and aluminum nitrate, more preferably at least two of copper nitrate, nickel nitrate, ferric nitrate, and aluminum nitrate. In some embodiments, the active metal soluble salt is nickel nitrate and ferric nitrate, the mass ratio of nickel nitrate to ferric nitrate is 1:(5-24), and the concentration of the metal cation is 0.01-1 mol / L. In other embodiments, the active metal soluble salt is ferric nitrate and aluminum nitrate, the mass ratio of ferric nitrate to aluminum nitrate is (1-2):1, and the concentration of the metal cation is 0.01-1 mol / L. In some embodiments, the active metal-soluble salt is nickel nitrate, ferric nitrate, and aluminum nitrate, with a mass ratio of 1:(7-11):(8-12) and a metal cation concentration of 0.01-1 mol / L. In other embodiments, the active metal-soluble salt is copper nitrate, ferric nitrate, and aluminum nitrate, with a mass ratio of 1:(3-5):(4-6) and a metal cation concentration of 0.01-1 mol / L. The type and proportion of the active metal-soluble salt can be adjusted according to the specific composition of the petrochemical high-calorific-value mixed gas.

[0040] In the method described in this invention, in order to improve the efficiency and loading capacity of the composite oxygen carrier, in step (1), the concentration of the metal cation in the active metal soluble salt solution is preferably 0.01-1 mol / L, more preferably 0.05-0.1 mol / L, specifically for example, 0.01 mol / L, 0.05 mol / L, 0.1 mol / L, 0.15 mol / L, 0.2 mol / L, 0.25 mol / L, 0.3 mol / L, 0.35 mol / L, 0.4 mol / L, 0.45 mol / L, 0.5 mol / L, 0.55 mol / L, 0.6 mol / L, 0.65 mol / L, 0.7 mol / L, 0.75 mol / L, 0.8 mol / L, 0.85 mol / L, 0.9 mol / L, 0.95 mol / L, or 1 mol / L.

[0041] In the method described in this invention, the specific activation process in step (1) may include: mixing an active metal soluble salt solution with an activating substance. The activating substance enriches and connects the pores of the biomass structure, thereby allowing the active metal soluble salt to more easily penetrate the biomass template and enter the inner layer of the particles, improving the efficiency and loading capacity of the composite oxygen carrier. The activation can be carried out under stirring, and the activation conditions include: a temperature of 20-100℃, preferably 50-80℃; a stirring rate of 10-50 r / min, preferably 20-30 r / min; and a time of 12-24 h, preferably 15-18 h.

[0042] In the method described in this invention, the activating substance can be at least one of acetic acid, hydrochloric acid, and nitric acid, preferably acetic acid. The concentration of the activating substance can be 0.001-0.01 mol / L, preferably 0.005-0.01 mol / L, specifically for example 0.001 mol / L, 0.002 mol / L, 0.003 mol / L, 0.004 mol / L, 0.005 mol / L, 0.006 mol / L, 0.007 mol / L, 0.008 mol / L, 0.009 mol / L, or 0.01 mol / L. To improve the efficiency and loading capacity of the composite oxygen carrier, the volume ratio of the active metal soluble salt solution to the activating substance is preferably 1:(10-1000), more preferably 1:(400-600).

[0043] In the method described in this invention, step (1) may further include preparing the biomass pellet template according to the following steps: drying and pulverizing the biomass pellets. The drying conditions include: a temperature of 95-120℃, preferably 95-105℃; and a time of 5-24h, preferably 7-12h. In the preparation of the biomass pellet template, the pulverized biomass pellet template is screened to obtain a biomass pellet template with a particle size of 0.1-2mm. The biomass pellets may be made from coconut shells. In some embodiments, acetic acid with a concentration of 0.001-0.01mol / L is used as an activating agent for the coconut shell biomass pre-made biomass pellets, which clears the particle channels on the surface of the coconut shell biomass pre-made biomass pellet template, expands the specific surface area inside and outside the particle, and improves the mixing degree of the coconut shell biomass pre-made biomass pellet template with copper nitrate, iron nitrate, and aluminum nitrate.

[0044] In the method described in this invention, in order to improve the specific surface area of ​​biomass and the efficiency and loading of the composite oxygen carrier, in step (1), the volume ratio of the active metal soluble salt solution to the biomass particle template is preferably 1:(0.1-0.3), more preferably 1:(0.15-0.25), and specifically, for example, 1:0.1, 1:0.15, 1:0.2, 1:0.25 or 1:0.3.

[0045] In the method described in this invention, in step (1), the adhesive may be polyvinyl alcohol and / or polyacryl alcohol. The concentration of the adhesive in the mixed solution may be 0.001-0.005 mol / L, preferably 0.002-0.005 mol / L, specifically, for example, 0.001 mol / L, 0.002 mol / L, 0.003 mol / L, 0.004 mol / L, or 0.005 mol / L.

[0046] In the method described in this invention, the stirring conditions in step (2) include: the temperature can be 60-100℃, preferably 50-80℃; the stirring rate can be 25-100r / min, preferably 27-32r / min; and the time can be 24-48h, preferably 24-30h.

[0047] In the method described in this invention, in order to increase the specific surface area of ​​biomass and improve the performance of oxygen carrier, the drying conditions in step (2) include: a temperature preferably of 95-120°C, more preferably of 95-105°C; and a time preferably of 24-48h, more preferably of 24-30h.

[0048] In the method described in this invention, in order to ensure that the oxygen carrier is conducive to gas-solid contact, significantly improves the specific surface area, and exhibits efficient conversion characteristics and carbon capture efficiency, the calcination conditions in step (2) include: the temperature is preferably 950-1100℃, more preferably 950-1050℃; the heating rate is preferably 2-8℃ / min, more preferably 3-6℃ / min; and the time is preferably 24-48h, more preferably 24-30h.

[0049] In the method described in this invention, in step (2), the particle size of the composite oxygen carrier after sieving is 0.15-1.5 mm. The sieving can be performed once or multiple times. In some embodiments, when the sieving is performed multiple times, composite oxygen carriers with a particle size range of 0.15-1.5 mm are selected by sieving; then composite oxygen carriers with a particle size greater than 1.5 mm are ground, and composite oxygen carriers with a particle size range of 0.15-1.5 mm are selected again by sieving; this process is repeated until the particle size of the prepared composite oxygen carriers is 0.15-1.5 mm; in addition, composite oxygen carriers with a particle size less than 0.15 mm are dissolved as raw materials in the active metal soluble salt solution obtained after activation in step (1) for reuse. In other embodiments, when the sieving is performed multiple times, composite oxygen carriers with a particle size range of 0.2-1.5 mm are selected by sieving; then composite oxygen carriers with a particle size greater than 1.5 mm are ground, and composite oxygen carriers with a particle size range of 0.2-1.5 mm are selected again by sieving; this process is repeated until the particle size of the prepared composite oxygen carriers is 0.2-1.5 mm; in addition, composite oxygen carriers with a particle size less than 0.2 mm are dissolved as raw materials in the active metal soluble salt solution obtained after activation in step (1) for reuse.

[0050] In some embodiments, the preparation method of the composite oxygen carrier of the present invention includes the following steps:

[0051] (1) An active metal soluble salt solution with a metal cation concentration of 0.01-1 mol / L is activated by passing an activating substance with a concentration of 0.001-0.01 mol / L at a temperature of 20-100℃ and a stirring rate of 10-50 r / min for 12-24 h. The activated active metal soluble salt solution, biomass pellet template and adhesive are mixed to obtain a mixed solution. In the mixed solution, the concentration of adhesive is 0.001-0.005 mol / L.

[0052] (2) The mixed solution is stirred at a temperature of 60-100℃ and a stirring rate of 25-100r / min for 24-48h, then dried at a temperature of 95-120℃ for 24-48h, and calcined at a temperature of 950-1100℃ for 24-48h. The composite oxygen carrier with a particle size range of 0.15-1.5mm is selected by sieving. Then the composite oxygen carrier with a particle size greater than 1.5mm is ground, and the composite oxygen carrier with a particle size range of 0.15-1.5mm is selected by sieving again. This process is repeated until the particle size of the prepared composite oxygen carrier is 0.15-1.5mm. In addition, the composite oxygen carrier with a particle size less than 0.15mm is dissolved as a raw material in the active metal soluble salt solution obtained after activation in step (1).

[0053] In other embodiments, the method for preparing the composite oxygen carrier of the present invention includes the following steps:

[0054] (1) Dry the biomass pellets at a temperature of 95-120℃ for 5-24 hours, then crush them, and screen the crushed biomass pellet templates to obtain biomass pellet templates with a particle size of 0.1-2mm.

[0055] (2) An active metal soluble salt solution with a metal cation concentration of 0.05-1 mol / L is activated by passing an activating substance with a concentration of 0.005-0.01 mol / L at a temperature of 50-80℃ and a stirring rate of 20-30 r / min for 15-18 h. The activated active metal soluble salt solution, biomass pellet template and adhesive are mixed to obtain a mixed solution. In the mixed solution, the concentration of adhesive is 0.002-0.005 mol / L.

[0056] (3) The mixed solution is stirred at a temperature of 50-80℃ and a stirring rate of 27-32 r / min for 24-30 h, then dried at a temperature of 95-105℃ for 24-30 h, heated to 950-1050℃ at a heating rate of 3-6℃ / min, and then calcined at a temperature of 950-1050℃ for 24-30 h. The composite oxygen carrier with a particle size range of 0.2-1.5 mm is selected by sieving. Then the composite oxygen carrier with a particle size greater than 1.5 mm is ground, and the composite oxygen carrier with a particle size range of 0.2-1.5 mm is selected by sieving again. This process is repeated until the particle size of the prepared composite oxygen carrier is 0.2-1.5 mm. In addition, the composite oxygen carrier with a particle size less than 0.2 mm is dissolved as a raw material in the active metal soluble salt solution obtained after activation in step (2).

[0057] This invention also provides a composite oxygen carrier prepared by the above-described method. The composite oxygen carrier according to this invention has a porous structure with a high specific surface area, which improves oxygen carrying capacity and lattice oxygen transport capacity, facilitating gas-solid contact. In the chemical looping combustion of petrochemical refining gas, it exhibits certain anti-sintering ability and the ability to oxidize mixed alkane fuel gas, displaying highly efficient conversion characteristics and carbon capture efficiency.

[0058] In the composite oxygen carrier described in this invention, in order to increase the specific surface area of ​​the oxygen carrier and thus improve its performance, the particle size of the composite oxygen carrier is preferably 0.15-1.5 mm, more preferably 0.2-1.5 mm.

[0059] In some embodiments, the active component of the composite oxygen carrier is iron oxide, and the inert component is aluminum oxide. In other embodiments, the active components of the composite oxygen carrier are nickel oxide and iron oxide. In still other embodiments, the active components of the composite oxygen carrier are copper oxide and iron oxide, and the inert component is aluminum oxide. Different metal oxides are uniformly mixed to form a composite oxygen carrier with good particle uniformity.

[0060] In some embodiments, the composition of the metal oxide in the composite oxygen carrier of the present invention can be adjusted over a wide range according to the gas composition of the petrochemical high-calorific-value mixed gas. When the total mass concentration of high-carbon alkanes such as ethane and propane (alkanes with more than two carbon atoms in their molecules) in the petrochemical high-calorific-value mixed gas is above 50%, the composite oxygen carrier can be a metal oxide with higher activity, such as nickel oxide or copper oxide. When the mass concentration of methane is below 50%, the composite oxygen carrier can be iron oxide, which has lower cost.

[0061] This invention also provides the application of the aforementioned composite oxygen carrier in the chemical looping combustion of high-calorific-value petrochemical mixed gases. According to the application described in this invention, the composite oxygen carrier is a porous metal oxide, whose oxygen-carrying capacity, lattice oxygen transport capacity, and structural characteristics are relatively stable and have strong resistance to breakage in the chemical looping combustion of high-temperature petrochemical mixed gases. It also possesses good anti-sintering ability and the ability to oxidize mixed alkane fuels.

[0062] The following examples further illustrate the composite oxygen carrier, its preparation method, and its application according to the present invention. These examples are implemented based on the technical solution of the present invention, providing detailed implementation methods and specific operating procedures; however, the scope of protection of the present invention is not limited to the following examples.

[0063] Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods in the art. Unless otherwise specified, the experimental materials used in the following embodiments are commercially available.

[0064] Example 1

[0065] Preparation of composite oxygen carrier:

[0066] (1) The biomass pellets pressed from coconut shells are dried at 100℃ for 8 hours and then crushed. The crushed biomass pellet templates are screened to obtain biomass pellet templates with a particle size of 0.1-2.0 mm.

[0067] (2) An active metal soluble salt solution with a metal cation concentration of 0.1 mol / L (the active metal soluble salts are ferric nitrate and aluminum nitrate, with a mass ratio of ferric nitrate and aluminum nitrate of 2:1 and a total mass of 50 g) was activated for 18 h at a temperature of 50 °C and a stirring rate of 20 r / min by passing it through acetic acid with a concentration of 0.005 mol / L. The volume ratio of the active metal soluble salt solution to acetic acid was 1:500. The activated active metal soluble salt solution was then mixed with a biomass particle template (the volume ratio of the active metal soluble salt solution to the biomass particle template was 1:0.15), and then mixed with polyvinyl alcohol (purchased from Aladdin Biochemical Technology Co., Ltd., brand name 363170) to obtain a mixed solution. In the mixed solution, the concentration of polyvinyl alcohol was 0.005 mol / L.

[0068] (3) The mixed solution is stirred at 80°C and 30 r / min for 24 h, then dried at 100°C for 48 h, heated to 1000°C at a rate of 5°C / min, and then calcined at 1000°C for 24 h. The composite oxygen carrier with a particle size range of 0.15-1.5 mm is selected by sieving. Then the composite oxygen carrier with a particle size greater than 1.5 mm is ground, and the composite oxygen carrier with a particle size range of 0.15-1.5 mm is selected by sieving again. This process is repeated until the particle size of the prepared composite oxygen carrier is 0.15-1.5 mm. The yield is 65%. In addition, the composite oxygen carrier with a particle size less than 0.15 mm is dissolved as raw material in the active metal soluble salt solution obtained after activation in step (2).

[0069] Characterization tests: The composite oxygen carrier prepared in Example 1 was characterized by scanning electron microscopy, such as... Figure 1 As shown.

[0070] Performance Testing: The chemical looping combustion performance of the oxygen-carrier petrochemical high-calorific-value mixed gas was evaluated using a fluidized bed reactor (reactor inner diameter 42 mm, height 500 mm, fluidized bed velocity 0.8 cm / s). In Example 1, the amount of the composite oxygen carrier prepared was 200 g, with a particle size range of 0.15-1.5 mm. The fluidizing gas was an N2 / CO2 mixture (N2 to CO2 concentration ratio 4:1), and the total gas flow rate was 10 L / min. The main fuel gas components were methane (87.31 wt%), ethane (4.17 wt%), and propane (1.78 wt%). The reaction temperature was 950 °C, and the reaction pressure was 101.325 kPa. The tail gas concentration diagram is shown below. Figure 2 As shown in Table 1, the composite oxygen carrier prepared in Example 1 was used for chemical looping combustion of petrochemical refining gas. The gas-mixture conversion rate, combustion efficiency, and carbon capture efficiency were measured and recorded. In this paper, the pressure is gauge pressure.

[0071] Example 2

[0072] Preparation of composite oxygen carrier:

[0073] (1) The biomass pellets pressed from coconut shells are dried at 100℃ for 8 hours and then crushed. The crushed biomass pellet templates are screened to obtain biomass pellet templates with a particle size of 0.1-2.0 mm.

[0074] (2) An active metal soluble salt solution with a metal cation concentration of 0.05 mol / L (the active metal soluble salts are nickel nitrate, ferric nitrate and aluminum nitrate, and the mass ratio of nickel nitrate, ferric nitrate and aluminum nitrate is 0.5:4.5:5, and the total mass is 100 g) is activated for 24 h at a temperature of 20 °C and a stirring rate of 10 r / min by acetic acid with a concentration of 0.01 mol / L (the volume ratio of the active metal soluble salt solution to acetic acid is 1:10). The activated active metal soluble salt solution is mixed with a biomass particle template (the volume ratio of the active metal soluble salt solution to the biomass particle template is 1:0.25), and then mixed with polyvinyl alcohol (purchased from Aladdin Biochemical Technology Co., Ltd., brand name 363170) to obtain a mixed solution. In the mixed solution, the concentration of polyvinyl alcohol is 0.002 mol / L.

[0075] (3) The mixed solution was stirred at 60°C and 25 r / min for 48 h, then dried at 100°C for 48 h, heated to 1000°C at a rate of 5°C / min, and then calcined at 1000°C for 24 h. The composite oxygen carrier with a particle size range of 0.2-1.5 mm was selected by sieving. Then the composite oxygen carrier with a particle size greater than 1.5 mm was ground, and the composite oxygen carrier with a particle size range of 0.2-1.5 mm was selected by sieving again. This process was repeated until the particle size of the prepared composite oxygen carrier was 0.2-1.5 mm. The yield was 55%. In addition, the composite oxygen carrier with a particle size less than 0.2 mm was dissolved as raw material in the active metal soluble salt solution obtained after activation in step (2).

[0076] Performance Testing: The chemical looping combustion performance of the oxygen-carrying petrochemical high-calorific-value mixed gas was evaluated using a fluidized bed reactor (reactor inner diameter 42 mm, height 500 mm, fluidized bed velocity 0.8 cm / s). The composite oxygen carrier prepared in Example 2 was used in an amount of 100 g, with a particle size range of 0.2-1.5 mm. The fluidizing gas was an N2 / CO2 mixture (N2 to CO2 concentration ratio 4:1), and the total gas flow rate was 10 L / min. The main fuel gas components were methane (87.31 wt%), ethane (4.17 wt%), and propane (1.78 wt%). The reaction temperature was 950 °C, and the reaction pressure was 101.325 kPa. The composite oxygen carrier prepared in Example 2 was used for chemical looping combustion of petrochemical refining gas. The mixed gas conversion rate, combustion efficiency, and carbon capture efficiency were measured and recorded in Table 1. The composite oxygen carrier prepared in Example 2 was subjected to 50 cycles of chemical loop combustion in petrochemical gas refining, and the conversion rate of the mixed gas was evaluated. Figure 3 The gas-mixed conversion rates for cycles 1-50 are shown.

[0077] Example 3

[0078] Preparation of composite oxygen carrier:

[0079] (1) The biomass pellets pressed from coconut shells are dried at 100℃ for 8 hours and then crushed. The crushed biomass pellet templates are screened to obtain biomass pellet templates with a particle size of 0.1-2.0 mm.

[0080] (2) An active metal soluble salt solution with a metal cation concentration of 0.05 mol / L (the active metal soluble salts are copper nitrate, ferric nitrate and aluminum nitrate, and the mass ratio of copper nitrate, ferric nitrate and aluminum nitrate is 1:4:5, and the total mass is 100 g) is activated for 12 h at a temperature of 100 °C and a stirring rate of 50 r / min by acetic acid with a concentration of 0.01 mol / L (the volume ratio of the active metal soluble salt solution to the activating substance is 1:1000). The activated active metal soluble salt solution is mixed with a biomass particle template (the volume ratio of the active metal soluble salt solution to the biomass particle template is 1:0.25), and then mixed with polyacrylamide (purchased from China National Pharmaceutical Group, brand name 25322-69-4) to obtain a mixed solution. In the mixed solution, the concentration of polyacrylamide is 0.005 mol / L.

[0081] (3) The mixed solution was stirred at 100°C and 100 r / min for 24 h, then dried at 100°C for 48 h, heated to 1000°C at a rate of 5°C / min, and then calcined at 1000°C for 24 h. The composite oxygen carrier with a particle size range of 0.15-1.5 mm was selected by sieving. Then the composite oxygen carrier with a particle size greater than 1.5 mm was ground, and the composite oxygen carrier with a particle size range of 0.15-1.5 mm was selected by sieving again. This process was repeated until the particle size of the prepared composite oxygen carrier was 0.15-1.5 mm. The yield was 56%. In addition, the composite oxygen carrier with a particle size less than 0.15 mm was dissolved as raw material in the active metal soluble salt solution obtained after activation in step (2).

[0082] Performance Testing: The chemical looping combustion performance of the oxygen-carrying petrochemical high-calorific-value mixed gas was evaluated using a fluidized bed reactor (reactor inner diameter 42 mm, height 500 mm, fluidized bed velocity 0.8 cm / s). The composite oxygen carrier prepared in Example 3 was used in an amount of 80 g, with a particle size range of 0.15-1.5 mm. The fluidizing gas was an N2 / CO2 mixture (N2 to CO2 concentration ratio 4:1), with a total gas flow rate of 10 L / min. The main fuel gas components were methane (87.31 wt%), ethane (4.17 wt%), and propane (1.78 wt%). The reaction temperature was 950 °C, and the reaction pressure was 101.325 kPa. The composite oxygen carrier prepared in Example 3 was used for chemical looping combustion of petrochemical refining gas. The mixed gas conversion rate, combustion efficiency, and carbon capture efficiency were measured and recorded in Table 1. The composite oxygen carrier prepared in Example 3 was subjected to 1-50 cycles of chemical loop combustion in petrochemical gas refining, and the conversion rate of the mixed gas was calculated and evaluated. Figure 3 As shown in the diagram, there are 50-100 cycles.

[0083] Example 4

[0084] Preparation of composite oxygen carrier:

[0085] (1) The biomass pellets pressed from coconut shells are dried at 120℃ for 5 hours and then crushed. The crushed biomass pellet templates are screened to obtain biomass pellet templates with a particle size of 0.1-2.0 mm.

[0086] (2) An active metal soluble salt solution with a metal cation concentration of 1 mol / L (the active metal soluble salts are nickel nitrate and ferric nitrate, the mass ratio of nickel nitrate and ferric nitrate is 1:9, and the total mass is 50 g) is activated for 18 h at a temperature of 60 °C and a stirring rate of 25 r / min by acetic acid with a concentration of 0.01 mol / L (the volume ratio of the active metal soluble salt solution to acetic acid is 1:500). The activated active metal soluble salt solution is mixed with a biomass particle template (the volume ratio of the active metal soluble salt solution to the biomass particle template is 1:0.3), and then mixed with polyvinyl alcohol (purchased from Aladdin Biochemical Technology Co., Ltd., brand name 363170) to obtain a mixed solution. In the mixed solution, the concentration of polyvinyl alcohol is 0.005 mol / L.

[0087] (3) The mixed solution was stirred at 80°C and 80 r / min for 28 h, then dried at 120°C for 24 h, heated to 1100°C at a rate of 8°C / min, and then calcined at 1100°C for 24 h. The composite oxygen carrier with a particle size range of 0.15-1.5 mm was selected by sieving. Then the composite oxygen carrier with a particle size greater than 1.5 mm was ground, and the composite oxygen carrier with a particle size range of 0.15-1.5 mm was selected by sieving again. This process was repeated until the particle size of the prepared composite oxygen carrier was 0.15-1.5 mm. The yield was 58%. In addition, the composite oxygen carrier with a particle size less than 0.15 mm was dissolved as raw material in the active metal soluble salt solution obtained after activation in step (2).

[0088] Performance Testing: The chemical looping combustion performance of the oxygen-carrying petrochemical high-calorific-value mixed gas was evaluated using a fluidized bed reactor (reactor inner diameter 42 mm, height 500 mm, fluidized bed velocity 0.8 cm / s). The composite oxygen carrier prepared in Example 4 was used in an amount of 100 g, with a particle size range of 0.15-1.5 mm. The fluidizing gas was an N2 / CO2 mixture (N2 to CO2 concentration ratio 4:1), and the total gas flow rate was 10 L / min. The main fuel gas components were methane (87.31 wt%), ethane (4.17 wt%), and propane (1.78 wt%). The reaction temperature was 1000 °C, and the reaction pressure was 101.325 kPa. The composite oxygen carrier prepared in Example 4 was used for chemical looping combustion of petrochemical refining gas. The mixed gas conversion rate, combustion efficiency, and carbon capture efficiency were measured and recorded in Table 1.

[0089] Example 5

[0090] Preparation of composite oxygen carrier:

[0091] (1) The biomass pellets pressed from coconut shells are dried at 95℃ for 24 hours and then crushed. The crushed biomass pellet templates are screened to obtain biomass pellet templates with a particle size of 0.1-2.0 mm.

[0092] (2) An active metal soluble salt solution with a metal cation concentration of 0.01 mol / L (the active metal soluble salts are nickel nitrate and ferric nitrate, the mass ratio of nickel nitrate and ferric nitrate is 1:9, and the total mass is 50 g) is activated for 18 h at a temperature of 60 °C and a stirring rate of 30 r / min by passing acetic acid with a concentration of 0.001 mol / L. The volume ratio of the active metal soluble salt solution to acetic acid is 1:500. The activated active metal soluble salt solution is mixed with a biomass particle template (the volume ratio of the active metal soluble salt solution to the biomass particle template is 1:0.1), and then mixed with polyvinyl alcohol (purchased from Aladdin Biochemical Technology Co., Ltd., brand name 363170) to obtain a mixed solution. In the mixed solution, the concentration of polyvinyl alcohol is 0.001 mol / L.

[0093] (3) The mixed solution is stirred at 60°C and 25 r / min for 24 h, then dried at 95°C for 48 h, heated to 950°C at a rate of 2°C / min, and then calcined at 950°C for 48 h. The composite oxygen carrier with a particle size range of 0.15-1.5 mm is selected by sieving. Then the composite oxygen carrier with a particle size greater than 1.5 mm is ground, and the composite oxygen carrier with a particle size range of 0.15-1.5 mm is selected by sieving again. This process is repeated until the particle size of the prepared composite oxygen carrier is 0.15-1.5 mm. The yield is 60%. In addition, the composite oxygen carrier with a particle size less than 0.15 mm is used as raw material and dissolved in the active metal soluble salt solution obtained after activation in step (2).

[0094] Performance Testing: The chemical looping combustion performance of the oxygen-carrying petrochemical high-calorific-value mixed gas was evaluated using a fluidized bed reactor (reactor inner diameter 42 mm, height 500 mm, fluidized bed velocity 0.8 cm / s). The composite oxygen carrier prepared in Example 5 was used in an amount of 100 g, with a particle size range of 0.15-1.5 mm. The fluidizing gas was an N2 / CO2 mixture (N2 to CO2 concentration ratio 4:1), and the total gas flow rate was 10 L / min. The main fuel gas components were methane (87.31 wt%), ethane (4.17 wt%), and propane (1.78 wt%). The reaction temperature was 950 °C, and the reaction pressure was 101.325 kPa. The composite oxygen carrier prepared in Example 5 was used for chemical looping combustion of petrochemical refining gas. The mixed gas conversion rate, combustion efficiency, and carbon capture efficiency were measured and recorded in Table 1.

[0095] Comparative Example 1

[0096] The composite oxygen carrier was prepared according to the method in Example 1, except that no biomass particle template was added. The specific preparation steps are as follows:

[0097] (1) An active metal soluble salt solution with a concentration of 0.1 mol / L (the active metal soluble salts are ferric nitrate and aluminum nitrate, the mass ratio of ferric nitrate and aluminum nitrate is 7:3, and the total mass is 50 g) is activated for 18 h at a temperature of 50 °C and a stirring rate of 20 r / min by passing acetic acid with a concentration of 0.005 mol / L. The volume ratio of the active metal soluble salt solution to acetic acid is 1:500. The activated active metal soluble salt solution is then mixed with polyvinyl alcohol (purchased from Aladdin Biochemical Technology Co., Ltd., brand name 363170) to obtain a mixed solution. In the mixed solution, the concentration of polyvinyl alcohol is 0.005 mol / L.

[0098] (2) The mixed solution is stirred at 80°C and 30 r / min for 24 h, then dried at 100°C for 48 h, heated to 1000°C at a rate of 5°C / min, and then calcined at 1000°C for 24 h. The composite oxygen carrier with a particle size range of 0.15-1.5 mm is selected by sieving. Then the composite oxygen carrier with a particle size greater than 1.5 mm is ground, and the composite oxygen carrier with a particle size range of 0.15-1.5 mm is selected by sieving again. This process is repeated until the particle size of the prepared composite oxygen carrier is 0.15-1.5 mm. The yield is 50%. In addition, the composite oxygen carrier with a particle size less than 0.15 mm is dissolved as raw material in the active metal soluble salt solution obtained after activation in step (1).

[0099] Performance Testing: The chemical looping combustion performance of the oxygen-carrying petrochemical high-calorific-value mixed gas was evaluated using a fluidized bed reactor (reactor inner diameter 42 mm, height 500 mm, fluidized bed velocity 0.8 cm / s). The composite oxygen carrier prepared in Comparative Example 1 was used in an amount of 100 g, with a particle size range of 0.15-1.5 mm. The fluidizing gas was an N2 / CO2 mixture (N2 to CO2 concentration ratio 4:1), and the total gas flow rate was 10 L / min. The main fuel gas components were methane (87.31 wt%), ethane (4.17 wt%), and propane (1.78 wt%). The reaction temperature was 1000 °C, and the reaction pressure was 101.325 kPa. The composite oxygen carrier prepared in Comparative Example 1 was used for chemical looping combustion of petrochemical refining gas. The mixed gas conversion rate, combustion efficiency, and carbon capture efficiency were measured and recorded in Table 1.

[0100] Comparative Example 2

[0101] The composite oxygen carrier was prepared according to the method in Example 1, except that activation was not performed. The specific preparation steps are as follows:

[0102] (1) The biomass pellets pressed from coconut shells are dried at 100℃ for 8 hours and then crushed. The crushed biomass pellet templates are screened to obtain biomass pellet templates with a particle size of 0.1-2.0 mm.

[0103] (2) A solution of soluble active metal cations with a concentration of 0.1 mol / L (the soluble active metal cations are ferric nitrate and aluminum nitrate, the mass ratio of ferric nitrate and aluminum nitrate is 7:3, and the total mass is 50 g) and a biomass pellet template (the volume ratio of the soluble active metal cations solution and the biomass pellet template is 1:0.15) are mixed, and then mixed with polyvinyl alcohol (purchased from Aladdin Biochemical Technology Co., Ltd., brand name 363170) to obtain a mixed solution. In the mixed solution, the concentration of polyvinyl alcohol is 0.005 mol / L.

[0104] (3) The mixed solution was stirred at 25°C and 30 r / min for 24 h, then dried at 100°C for 48 h, heated to 1000°C at a rate of 5°C / min, and then calcined at 1000°C for 24 h. The composite oxygen carrier with a particle size range of 0.15-1.5 mm was selected by sieving. Then the composite oxygen carrier with a particle size greater than 1.5 mm was ground, and the composite oxygen carrier with a particle size range of 0.15-1.5 mm was selected by sieving again. This process was repeated until the particle size of the prepared composite oxygen carrier was 0.15-1.5 mm. The yield was 51%. In addition, the composite oxygen carrier with a particle size less than 0.15 mm was dissolved as raw material in the active metal soluble salt solution in step (2).

[0105] Performance Testing: The chemical looping combustion performance of the oxygen-carrying petrochemical high-calorific-value mixed gas was evaluated using a fluidized bed reactor (reactor inner diameter 42 mm, height 500 mm, fluidized bed velocity 0.8 cm / s). The composite oxygen carrier prepared in Comparative Example 2 was used in an amount of 100 g, with a particle size range of 0.15-1.5 mm. The fluidizing gas was an N2 / CO2 mixture (N2 to CO2 concentration ratio 4:1), and the total gas flow rate was 10 L / min. The main fuel gas components were methane (87.31 wt%), ethane (4.17 wt%), and propane (1.78 wt%). The reaction temperature was 1000 °C, and the reaction pressure was 101.325 kPa. The composite oxygen carrier prepared in Comparative Example 2 was used for chemical looping combustion of petrochemical refining gas. The mixed gas conversion rate, combustion efficiency, and carbon capture efficiency were measured and recorded in Table 1.

[0106] The formula for calculating the yield rate is: (Number of qualified products / Total production quantity) × 100%

[0107] Formula for calculating the conversion rate of gas-fuel mixture:

[0108]

[0109] Formula for calculating combustion efficiency:

[0110]

[0111] Among them, H i The lower heating value of substance i, such as CO, CH4, H2, and fuels; M i Let m be the molar mass of substance i; m be the molar mass of substance i. fuel This indicates the mass of gaseous fuel added in each cycle.

[0112] Formula for calculating carbon capture efficiency:

[0113] It is the ratio of carbon released during the reduction stage to the total carbon in the high-calorific-value petrochemical mixture. If no carbon-containing gas is released during the oxidation stage, the carbon capture efficiency is 100%. The calculation formula is as follows:

[0114]

[0115] Table 1

[0116] serial number Gas-mixed conversion rate Combustion efficiency Carbon capture efficiency Example 1 0.89 0.91 0.93 Example 2 0.95 0.97 0.99 Example 3 0.93 0.95 0.99 Example 4 0.92 0.93 0.91 Example 5 0.88 0.89 0.91 Comparative Example 1 0.80 0.80 0.89 Comparative Example 2 0.83 0.84 0.91

[0117] As can be seen from the results in Table 1, in petrochemical gasification chemical loop combustion, the embodiment using the composite oxygen carrier described in this invention has a high mixed gas conversion rate, combustion efficiency, and carbon capture efficiency.

[0118] pass Figure 1 The results show that the composite oxygen carrier prepared using Example 1 has a loose and porous morphology and well-developed and interconnected pores.

[0119] pass Figure 2 The results show that the composite oxygen carrier prepared using Example 1 has the characteristic of high efficiency in converting petrochemical gas.

[0120] pass Figure 3 The results show that the composite oxygen carriers prepared using Examples 2 and 3 have the characteristic of high mixer conversion rate.

[0121] The preferred embodiments of the present invention have been described in detail above; however, the present invention is not limited thereto. Within the scope of the inventive concept, various simple modifications can be made to the technical solutions of the present invention, including combinations of various technical features in any other suitable manner. These simple modifications and combinations should also be considered as the content disclosed in the present invention and are all within the protection scope of the present invention.

Claims

1. A method for preparing a composite oxygen carrier, characterized in that, The method includes the following steps: (1) Activate the active metal soluble salt solution, and mix the activated active metal soluble salt solution, biomass particle template and adhesive to obtain a mixed solution; (2) The mixed solution is stirred, dried, calcined and sieved in sequence to obtain a composite oxygen carrier.

2. The method according to claim 1, characterized in that, In step (1), the active metal in the active metal soluble salt solution is at least one of copper, nickel, iron and aluminum.

3. The method according to claim 1 or 2, characterized in that, In step (1), the active metal soluble salt in the active metal soluble salt solution is at least one of copper nitrate, nickel nitrate, iron nitrate and aluminum nitrate.

4. The method according to any one of claims 1-3, characterized in that, In step (1), the concentration of the metal cation in the active metal soluble salt solution is 0.01-1 mol / L.

5. The method according to any one of claims 1-4, characterized in that, In step (1), the specific activation process includes: mixing the active metal soluble salt solution and the activating substance; Preferably, the activating substance is at least one of acetic acid, hydrochloric acid, and nitric acid; Preferably, the concentration of the activating substance is 0.001-0.01 mol / L.

6. The method according to any one of claims 1-5, characterized in that, In step (1), the method further includes preparing the biomass pellet template according to the following steps: drying and pulverizing the biomass pellets; Preferably, the drying conditions include: a temperature of 95-120℃ and a time of 5-24 hours; Preferably, the particle size of the biomass pellet template is 0.1-2 mm.

7. The method according to any one of claims 1-6, characterized in that, In step (1), the volume ratio of the active metal soluble salt solution to the biomass particle template is 1:(0.1-0.3).

8. The method according to any one of claims 1-7, characterized in that, In step (1), the adhesive is polyvinyl alcohol and / or polyacryl alcohol; Preferably, the concentration of the adhesive in the mixed solution is 0.001-0.005 mol / L.

9. The method according to any one of claims 1-8, characterized in that, In step (2), the stirring conditions include: a temperature of 60-100℃, a stirring rate of 25-100r / min, and a time of 24-48h.

10. The method according to any one of claims 1-9, characterized in that, In step (2), the drying conditions include a temperature of 95-120°C and a time of 24-48 hours.

11. The method according to any one of claims 1-10, characterized in that, In step (2), the calcination conditions include a temperature of 950-1100℃ and a time of 24-48h.

12. A composite oxygen carrier prepared by the method according to any one of claims 1-11.

13. The composite oxygen carrier according to claim 12, characterized in that, The particle size of the composite oxygen carrier is 0.15-1.5 mm.

14. The application of the composite oxygen carrier according to claim 12 or 13 in chemical looping combustion of petrochemical high-calorific-value mixed gas.

Images