A method for preparing a self-activated metal-modified activated coke catalyst for desulfurization and denitrification.

Abstract

This invention provides a method for preparing a self-activated metal-modified activated coke catalyst for desulfurization and denitrification, comprising the following steps: (1) thoroughly mixing at least one of transition metal carbonate powder and natural ore powder containing transition metal carbonate with coal powder, adding water or sulfuric acid aqueous solution and binder, thoroughly mixing, extruding and molding, and drying; (2) placing the molded material obtained in step (1) into a reactor, sealing the reactor, raising the temperature of the reactor to 800-1000℃ and holding it at this temperature for 1-3 hours for activation treatment. During the heating and holding process, the pressure in the furnace cavity is controlled to be slightly positive pressure by the control valve of the reactor. During the activation treatment, the carbon dioxide generated by the decomposition of transition metal carbonate acts as an activator to self-activate the activated coke under slightly positive pressure conditions. After the holding period, the activated coke is obtained. This invention can realize the efficient and low-cost preparation of catalytic low-temperature desulfurization and denitrification activated coke and the reduction of CO2 emissions.

Description

Technical Field

[0001] This invention belongs to the field of desulfurization and denitrification catalysts, and relates to a method for preparing a self-activated metal-modified activated coke catalyst for desulfurization and denitrification. Background Technology

[0002] Based on my country's energy structure, coal-smoke pollution caused by coal combustion will remain the main form of air pollution in my country in the future, with SO2 and NO emissions from coal combustion being particularly significant. x SO2 and fine particulate matter will remain major air pollutants in my country. Therefore, the ongoing and in-depth study of SO2 and NOx will continue. x Emission control remains a serious concern. The activated coke (carbon) method for flue gas desulfurization and denitrification is a resource-efficient, low-temperature desulfurization and denitrification technology widely used in my country's air pollution control efforts. With the increasing NOx emissions from non-power industries in my country... x With increasingly stringent emission controls, the requirements for denitrification in activated coke flue gas desulfurization and denitrification processes are also increasing. Addressing the issues of low flue gas temperatures and large temperature fluctuations in many industrial processes, improving the low-temperature denitrification performance of activated coke has become a key research focus for activated coke-based flue gas desulfurization and denitrification processes.

[0003] To address the issues of low desulfurization capacity and poor denitrification activity in existing activated coke catalysts, transition metal-modified activated coke has gained widespread acceptance among researchers and engineers. Currently, the main methods for transition metal modification of activated coke are impregnation and blending. Among these, the blending method has gradually gained more application due to its simple production process and lower production cost. However, activated coke using blended metal oxides as the active component still requires a long-term high-temperature carbonization and activation process during preparation. For example, in industrial plants, when using steam or carbon dioxide to activate transition metal-supported activated coke, the activation process needs to last 24–72 hours depending on indicators such as iodine value. On the one hand, the long activation time significantly increases the catalyst preparation cost; on the other hand, the continuous activation with additional carbon dioxide over a long period generates a large amount of greenhouse gases, which is detrimental to greenhouse gas emission reduction and environmental protection. Summary of the Invention

[0004] To address the issues of high production costs and adverse effects on greenhouse gas emission reduction associated with current transition metal-supported activated coke (carbon) catalysts for desulfurization and denitrification prepared by blending methods, this invention provides a method for preparing self-activated metal-modified activated coke catalysts for desulfurization and denitrification, thereby achieving efficient and low-cost preparation of catalytically typed low-temperature desulfurization and denitrification activated coke and CO2 emission reduction.

[0005] To achieve the above-mentioned objectives, the technical solution adopted by the present invention is as follows:

[0006] A method for preparing a self-activated metal-modified activated coke catalyst for desulfurization and denitrification includes the following steps:

[0007] (1) The carbonate powder and coal powder are thoroughly mixed to obtain a mixture. The mixture is then thoroughly mixed with water or sulfuric acid aqueous solution and a binder, and then extruded and dried to obtain a molded material. The carbonate powder is at least one of transition metal carbonate powder and natural ore powder containing transition metal carbonate.

[0008] (2) Place the molding material in the reactor, seal the reactor, raise the temperature of the reactor to 800-1000℃ and keep it at this temperature for 1-3 hours for activation treatment. During the heating and holding process, the pressure in the furnace cavity is controlled by the control valve of the reactor to be at a slight positive pressure of no more than 1000Pa. During the activation process, the coal powder in the molding material is carbonized, the carbonate of the transition metal is decomposed to produce carbon dioxide and oxides of the transition metal. The carbon dioxide produced by the decomposition acts as an activator to self-activate the activated coke under the slight positive pressure condition. After the holding period, the activated coke catalyst for desulfurization and denitrification is obtained.

[0009] In step (1) of the above technical solution, it is preferred to control the amount of water or sulfuric acid aqueous solution added to 5% to 15% of the coal powder mass, it is preferred to control the amount of binder added to 35% to 40% of the coal powder mass, and it is preferred to control the amount of carbonate powder added to make the mass of transition metal at least 15% of the coal powder mass.

[0010] In the above technical solution, the transition metal is manganese, cobalt, copper, or iron, that is, the carbonate of the transition metal is manganese carbonate, cobalt carbonate, copper carbonate, or iron carbonate. The transition metal is preferably manganese, cobalt, or copper.

[0011] In the above technical solution, the natural ore containing transition metal carbonates is preferably manganese carbonate ore. Compared with using manganese carbonate, cobalt carbonate, copper carbonate, or iron carbonate, using manganese carbonate ore can effectively reduce the cost of the catalyst. Preferably, the manganese carbonate ore contains at least 40 wt% manganese carbonate, and more preferably, it contains 50 wt% to 60 wt% manganese carbonate.

[0012] In the above technical solution, the concentration of the sulfuric acid aqueous solution is preferably 2wt% to 5wt%.

[0013] In step (1) of the above technical solution, based on the requirements for the iodine value of the activated coke catalyst in actual applications, the iodine value of the activated coke catalyst can be made to reach the designed iodine value by supplementing with a chemical activator. One feasible method is: in step (1), a chemical activator is added when preparing the mixture. The carbonate powder, chemical activator, and coal powder are thoroughly mixed to obtain the mixture. The chemical activator is sodium hydroxide, potassium hydroxide, or phosphoric acid. The amount of chemical activator added is determined according to the requirements for the iodine value of the activated coke catalyst in actual applications. Generally, the amount of chemical activator added can be 1% to 5% of the coal powder mass.

[0014] In step (2) of the above technical solution, depending on the requirements of the iodine value of the activated coke catalyst in actual application, it can also be activated by supplementing the reactor with water vapor, carbon dioxide or air. Since the carbon dioxide generated by the decomposition of the transition metal carbonate in step (2) has played a significant self-activation role, the above technical solution of the present invention can effectively reduce the amount of water vapor, carbon dioxide or air introduced compared with the existing method of preparing activated coke catalyst loaded with transition metal by blending.

[0015] In step (2) of the above technical solution, it is preferable to control the pressure in the furnace cavity to be maintained at 200-400 Pa by the control valve of the reactor.

[0016] In step (2) of the above technical solution, the reactor can be a tube furnace or a box furnace, and the furnace cavity of the tube furnace or box furnace can withstand and maintain a pressure of at least 1000 Pa.

[0017] In step (2) of the above technical solution, it is preferable to raise the temperature of the reactor to 800-1000°C at a heating rate of 5-20°C / min.

[0018] In step (1) of the above technical solution, it is preferable to control the amount of carbonate powder added so that the mass of the transition metal is 15% to 30% of the mass of coal powder.

[0019] In step (1) of the above technical solution, the transition metal carbonate powder and the natural ore powder containing transition metal carbonate are preferably powders that have passed through a sieve of 150 to 300 mesh.

[0020] In the above technical solution, the binder can be coal tar or lignocellulose.

[0021] The reason why the above technical solution can significantly shorten the activation process time to 1-3 hours is mainly because the process of decomposing the carbonate of the transition metal to produce carbon dioxide during the activation process is a pore-forming process. This activation process from the inside out is significantly faster than the existing technology that uses gases such as water vapor and carbon dioxide to carry out the activation process from the outside in.

[0022] This invention also provides an activated coke catalyst for desulfurization and denitrification prepared by the above-mentioned technical solution, wherein the specific surface area of ​​the activated coke catalyst for desulfurization and denitrification is 300 m². 2 / g or higher, for example, the specific surface area is usually between 318 and 459 m². 2 The concentration of NO in the desulfurization and denitrification catalyst is between 400 ppm and 400 ppm, 10.0 vol.% O2 in the inlet, with nitrogen as the balance gas, and a reaction space velocity of 2000 h⁻¹. -1 Under reaction conditions of 175℃, the conversion rate of NO is approximately between 50% and 70%. This desulfurization and denitrification activated coke catalyst was used at an SO2 inlet concentration of 3000 ppm, an O2 inlet concentration of 10.0 vol.%, with nitrogen as the balance gas, and a reaction space velocity of 1000 h⁻¹. -1 The sulfur capacity under reaction temperature of 120℃ is above 55 mg / g, for example, the sulfur capacity is usually between 56.8 and 105.1 mg / g.

[0023] Compared with the prior art, the technical solution provided by the present invention has the following beneficial technical effects:

[0024] 1. This invention provides a method for preparing a self-activated metal-modified activated coke catalyst for desulfurization and denitrification. The key lies in using transition metal carbonates and / or natural ores containing transition metal carbonates as the source of the catalyst's active components. The transition metal carbonates decompose under high-temperature conditions to produce transition metal oxides and carbon dioxide. The transition metal oxides serve as the catalytically active component of the catalyst, while carbon dioxide acts as an activator to achieve self-activation of the activated coke. Since the process of transition metal carbonates decomposing to produce carbon dioxide during activation is essentially a pore-forming process, this inside-out activation efficiency is significantly higher than that of existing technologies that use gases such as water vapor or carbon dioxide to promote pore structure development. Therefore, the method of this invention can significantly shorten the activation time. Furthermore, this method can reduce or even eliminate the use of external activation gases, effectively reducing energy consumption and saving production costs, resulting in a significant cost advantage. It also effectively reduces the emission of greenhouse gases such as CO2 during catalyst preparation, increasing the environmental friendliness of the preparation method.

[0025] 2. Compared with existing methods for preparing activated coke catalysts supported on transition metals through blending, the method of the present invention has a simpler process and a shorter catalyst preparation time, enabling efficient and low-cost preparation of activated coke catalysts supported on transition metals. At the same time, the denitrification and desulfurization performance of the catalyst prepared by the method of the present invention can meet the requirements of practical applications. All of these factors are conducive to the promotion and application of the method of the present invention in practical scenarios. Attached Figure Description

[0026] Figure 1 Figure (a) shows the denitrification performance test results for A1, A2, and A3. Figure 1 Figure (b) shows the desulfurization breakthrough curves for A1, A2, and A3.

[0027] Figure 2 Figure (a) shows the denitrification performance test results of B1 and B2, and Figure (b) shows the desulfurization breakthrough curves of B1 and B2.

[0028] Figure 3 These are the nitrogen adsorption-desorption curves for A3, B1, and B2.

[0029] Figure 4 These are the XRD patterns of A3 and B2.

[0030] Figure 5 Figure (a) shows the denitrification performance test results for C1 to C4. Figure 5 Figure (b) shows the desulfurization breakthrough curves for C1 to C4.

[0031] Figure 6 Figure (a) shows the denitrification performance test results for D1, D2, and B2. Figure 6 Figure (b) shows the desulfurization breakthrough curves for D1 and D2.

[0032] Figure 7 These are the nitrogen adsorption-desorption curves for D1 and D2.

[0033] Figure 8 These are the infrared spectra of D1 and D2.

[0034] Figure 9 Figure (a) shows the denitrification performance test results for E1, E2, and B2. Figure 9 Figure (b) shows the desulfurization breakthrough curves for E1 and E2.

[0035] Figure 10 These are the nitrogen adsorption-desorption curves for E1, E2, and B2.

[0036] Figure 11 These are the denitrification performance test results of the activated coke catalysts for desulfurization and denitrification prepared in Examples 6-8. Detailed Implementation

[0037] The following examples further illustrate the preparation method of the self-activated metal-modified activated coke catalyst for desulfurization and denitrification provided by the present invention. It should be noted that the following examples are only for further illustration of the present invention and should not be construed as limiting the scope of protection of the present invention. Any non-essential improvements and adjustments made to the present invention by those skilled in the art based on the above-described content are still within the scope of protection of the present invention.

[0038] In the following examples, unless otherwise specified, the experimental conditions were performed under conventional conditions or conditions recommended by the manufacturer. Unless otherwise specified, the reagents or instruments used were all commercially available products.

[0039] Example 1

[0040] In this embodiment, a method for preparing the self-activated metal-modified activated coke catalyst for desulfurization and denitrification according to the present invention is provided, the steps of which are as follows:

[0041] (1) Mix manganese carbonate powder that has passed through a 200-mesh sieve and coal powder that has passed through a 200-mesh sieve thoroughly to obtain a mixture. Add water and coal tar to the mixture and mix thoroughly. Then, use an extrusion molding machine to extrude the mixture and dry it to obtain semi-coke particles with a diameter of 6 mm.

[0042] In this step, the amount of water added is controlled to be 10% of the mass of the mixture, and the amount of coal tar added is controlled to be 40% of the mass of the mixture. In this step, a total of 3 sets of experiments were conducted. In each set of experiments, manganese carbonate powder was mixed with coal powder at the proportions of 5%, 10% and 15% of the mass of manganese as a percentage of the mass of coal powder, respectively.

[0043] (2) Place the semi-coke particles in a tubular furnace, seal the tubular furnace, raise the temperature of the tubular furnace to 800℃ at a heating rate of 5-20℃ / min, and hold at this temperature for 2 hours for activation treatment. During the heating and holding process, control the pressure in the tubular furnace cavity to maintain at 300±50Pa through the control valve of the tubular furnace. After the holding is completed, cool naturally to room temperature to obtain the activated coke catalyst for desulfurization and denitrification.

[0044] The activated coke catalysts for desulfurization and denitrification prepared in the three sets of experiments corresponding to the mixing of manganese carbonate powder with coal powder in step (1) at proportions of 5%, 10%, and 15% of the mass of manganese powder are respectively denoted as A1, A2, and A3.

[0045] The A1, A2, and A3 prepared in this embodiment were used in an NH3-SCR reaction to test their denitrification activity. The test conditions were: NO inlet concentration 400 ppm, NH3 inlet concentration 400 ppm, O2 inlet concentration 10.0 vol.%, nitrogen as the balance gas, and reaction space velocity 2000 h⁻¹.-1 The reaction temperature was 175℃. The denitrification performance of A1, A2, and A3, i.e., the change in NO conversion rate over time when A1, A2, and A3 are used in the denitrification reaction, is shown in the figure below. Figure 1 As shown in Figure (a). The desulfurization performance of A1, A2, and A3 prepared in this embodiment was tested under the following conditions: SO2 inlet concentration 3000 ppm, O2 inlet concentration 10.0 vol.%, nitrogen as nitrogen balance gas, and reaction space velocity 1000 h⁻¹. -1 The reaction temperature is 120℃. The desulfurization breakthrough curves of A1, A2, and A3 are as follows: Figure 1 As shown in Figure (b), the sulfur capacities of A1, A2, and A3 are 47.1 mg / g, 74.0 mg / g, and 89.4 mg / g, respectively. Figure 1 It can be seen that the denitrification performance of A1, A2, and A3 gradually increases, as does their desulfurization performance. The nitrogen adsorption-desorption curve of A3 is shown below. Figure 3 As shown, by Figure 3 It can be seen that the specific surface area S of A3 BET 350m 2 / g. The XRD pattern of A3 is as follows Figure 4 As shown, by Figure 4 It can be seen that the phase composition of A3 mainly includes SiO2 and MnO.

[0046] Example 2

[0047] In this embodiment, a method for preparing the self-activated metal-modified activated coke catalyst for desulfurization and denitrification according to the present invention is provided, the steps of which are as follows:

[0048] (1) Natural manganese carbonate ore was crushed and passed through a 200-mesh sieve to obtain manganese carbonate ore powder. The main components and mass content of the natural manganese carbonate ore were: Mn 34.2%, Si 9.17%, Mg 5.32%, Al 2.75%, Fe 2.52%, and S 1.21%. The manganese carbonate ore powder and coal powder that had passed through a 200-mesh sieve were thoroughly mixed to obtain a mixture. Water and coal tar were added to the mixture and thoroughly mixed. Then, the mixture was extruded and molded using an extrusion molding machine and dried to obtain semi-coke particles with a diameter of 6 mm.

[0049] In this step, the amount of water added is controlled to be 10% of the mass of the mixture, and the amount of coal tar added is controlled to be 40% of the mass of the mixture. In this step, two sets of experiments are conducted. In each set of experiments, manganese carbonate ore powder is mixed with coal powder at a ratio of 10% and 15% of the mass of manganese, respectively.

[0050] (2) Place the semi-coke particles in a muffle furnace, seal the muffle furnace, raise the temperature of the muffle furnace to 800°C at a heating rate of 5-20°C / min, and hold at this temperature for 2 hours for activation treatment. During the heating and holding process, control the pressure inside the muffle furnace cavity to maintain at 300±50Pa through the control valve of the muffle furnace. After the holding is completed, cool naturally to room temperature to obtain the activated coke catalyst for desulfurization and denitrification.

[0051] The desulfurization and denitrification activated coke catalysts prepared in the two sets of experiments corresponding to the mixing of manganese carbonate ore powder and coal powder in step (1) with manganese mass accounting for 10% and 15% of the coal powder mass are respectively denoted as B1 and B2.

[0052] The B1 and B2 prepared in this example were used in an NH3-SCR reaction to test their denitrification activity, and the test conditions were the same as in Example 1. The denitrification performance of B1 and B2, i.e., the change curve of NO conversion rate over time when B1 and B2 are used in the denitrification reaction, is shown in the figure below. Figure 2 As shown in Figure (a). The desulfurization performance of B1 and B2 prepared in this embodiment was tested under the same conditions as in Example 1. The desulfurization breakthrough curves of B1 and B2 are shown below. Figure 2 As shown in Figure (b), the sulfur capacities of B1 and B2 are 57.0 mg / g and 74.8 mg / g, respectively. Figure 2 It can be seen that the denitrification performance of B1 and B2 gradually increases, and their desulfurization performance also gradually increases. The nitrogen adsorption-desorption curves of B1 and B2 are shown below. Figure 3 As shown, by Figure 3 It can be seen that the specific surface area S of B1 and B2 BET 285m respectively 2 / g and 318m 2 The XRD pattern of / g. B2 is as follows: Figure 4 As shown, by Figure 4 It can be seen that the phase composition of B2 mainly includes SiO2 and MnO.

[0053] Example 3

[0054] In this embodiment, a method for preparing the self-activated metal-modified activated coke catalyst for desulfurization and denitrification according to the present invention is provided, the steps of which are as follows:

[0055] (1) Natural manganese carbonate ore was crushed and passed through a 200-mesh sieve to obtain manganese carbonate ore powder. The main components and mass content of the natural manganese carbonate ore were: Mn 34.2%, Si 9.17%, Mg 5.32%, Al 2.75%, Fe 2.52%, and S 1.21%. The manganese carbonate ore powder and coal powder that had passed through a 200-mesh sieve were thoroughly mixed to obtain a mixture. Water and coal tar were added to the mixture and thoroughly mixed. Then, the mixture was extruded and molded using an extrusion molding machine and dried to obtain semi-coke particles with a diameter of 6 mm.

[0056] In this step, the amount of water added is controlled to be 10% of the mass of the mixture, the amount of coal tar added is controlled to be 40% of the mass of the mixture, and the manganese carbonate ore powder is mixed with the coal powder according to the ratio of manganese mass to coal powder mass of 15%.

[0057] (2) In this step, the following 4 sets of experiments were conducted:

[0058] Semi-coke particles were placed in a tubular furnace, which was then sealed. The temperature of the tubular furnace was raised to 850°C at a heating rate of 5–20°C / min and held at this temperature for 2 hours for activation treatment. During the heating and holding process, the pressure inside the tubular furnace was controlled by the control valve of the tubular furnace to maintain at 300±50Pa. After the holding period, the furnace was naturally cooled to room temperature to obtain an activated coke catalyst for desulfurization and denitrification, denoted as C1.

[0059] Semi-coke particles were placed in a tubular furnace, which was then sealed. The temperature of the tubular furnace was increased to 900℃ at a heating rate of 5–20℃ / min and held at this temperature for 2 hours for activation treatment. During the heating and holding process, the pressure inside the tubular furnace cavity was controlled by the control valve of the tubular furnace to maintain at 300±50Pa. After the holding period, the furnace was naturally cooled to room temperature to obtain an activated coke catalyst for desulfurization and denitrification, denoted as C2.

[0060] Semi-coke particles were placed in a tubular furnace, which was then sealed. The temperature of the tubular furnace was raised to 950°C at a heating rate of 5–20°C / min and held at that temperature for 1 hour for activation treatment. During the heating and holding process, the pressure inside the tubular furnace was controlled by the control valve of the tubular furnace to maintain at 300±50Pa. After the holding period, the furnace was naturally cooled to room temperature to obtain an activated coke catalyst for desulfurization and denitrification, denoted as C3.

[0061] Semi-coke particles were placed in a tubular furnace, which was then sealed. The temperature of the tubular furnace was raised to 850°C at a heating rate of 5–20°C / min and held at this temperature for 3 hours for activation treatment. During the heating and holding process, the pressure inside the tubular furnace was controlled by the control valve of the tubular furnace to maintain at 300±50Pa. After the holding period, the furnace was naturally cooled to room temperature to obtain an activated coke catalyst for desulfurization and denitrification, denoted as C4.

[0062] The C1-C4 compounds prepared in this example were used in an NH3-SCR reaction to test their denitrification activity, under the same test conditions as in Example 1. The denitrification performance of C1-C4, i.e., the change curve of NO conversion rate over time when C1-C4 is used in the denitrification reaction, is shown in the figure below. Figure 5 As shown in Figure (a), the desulfurization performance of C1-C4 prepared in this embodiment was tested under the same conditions as in Example 1. The desulfurization breakthrough curves of C1-C4 are shown below. Figure 5As shown in Figure (b), the sulfur capacities of C1 to C4 are 80.8 mg / g, 92.4 mg / g, 62.6 mg / g and 76.8 mg / g, respectively.

[0063] Example 4

[0064] In this embodiment, a method for preparing the self-activated metal-modified activated coke catalyst for desulfurization and denitrification according to the present invention is provided, the steps of which are as follows:

[0065] (1) Natural manganese carbonate ore was crushed and passed through a 200-mesh sieve to obtain manganese carbonate ore powder. The main components and mass content of the natural manganese carbonate ore were: Mn 34.2%, Si 9.17%, Mg 5.32%, Al 2.75%, Fe 2.52%, and S 1.21%. The manganese carbonate ore powder and coal powder that had passed through a 200-mesh sieve were thoroughly mixed to obtain a mixture. Sulfuric acid aqueous solution and coal tar were added to the mixture and thoroughly mixed. Then, the mixture was extruded and molded using an extrusion molding machine and dried to obtain semi-coke particles with a diameter of 6 mm.

[0066] In this step, two sets of experiments were conducted. In each set of experiments, the amount of sulfuric acid aqueous solution added was controlled to be 10% of the mass of the mixture. The concentrations of sulfuric acid aqueous solution used in each experimental set were 2wt% and 3wt%, respectively. In this step, the amount of coal tar added was controlled to be 40% of the mass of the mixture. Manganese carbonate ore powder was mixed with coal powder at a ratio of 15% of the mass of coal powder.

[0067] (2) Place the semi-coke particles in a tubular furnace, seal the tubular furnace, raise the temperature of the tubular furnace to 800℃ at a heating rate of 5-20℃ / min, and hold at this temperature for 2 hours for activation treatment. During the heating and holding process, control the pressure in the tubular furnace cavity to maintain at 300±50Pa through the control valve of the tubular furnace. After the holding is completed, cool naturally to room temperature to obtain the activated coke catalyst for desulfurization and denitrification.

[0068] The activated coke catalysts for desulfurization and denitrification prepared in the two sets of experiments using sulfuric acid aqueous solutions with concentrations of 2wt% and 3wt% in step (1) are respectively denoted as D1 and D2.

[0069] The D1 and D2 prepared in this example, and the B2 prepared in Example 2, were used in an NH3-SCR reaction to test their denitrification activity. The test conditions were the same as in Example 1. The denitrification performance of D1, D2, and B2, i.e., the change curves of NO conversion rate over time when D1, D2, and B2 were used in the denitrification reaction, are shown in the figure below. Figure 6 As shown in Figure (a), the denitrification performance of D1 and D2 was enhanced compared to B2. The desulfurization performance of D1 and D2 prepared in this embodiment was tested under the same conditions as in Example 1. The desulfurization breakthrough curves of D1 and D2 are shown below. Figure 6As shown in Figure (b), the sulfur capacities of D1 and D2 are 70.0 mg / g and 56.8 mg / g, respectively. The sulfur capacities of D1 and B2 are comparable.

[0070] The nitrogen adsorption-desorption curves of D1 and D2 are as follows: Figure 7 As shown, by Figure 7 It can be seen that the specific surface area S of D1 and D2 BET 320m respectively 2 / g and 335m 2 / g, relative to B2, the specific surface area S of D1 and D2 BET There has been an increase. The infrared spectra of D1 and D2 are as follows: Figure 8 As shown, by Figure 8 It can be seen that it is located at 614.52cm -1 and 613.26cm -1 The peak at 676.80 cm⁻¹ is attributed to SO or S=O. -1 and 676.90cm -1 The peak at 1570.00 cm⁻¹ belongs to O=C=O. -1 The nearby peaks belong to C=O.

[0071] Example 5

[0072] In this embodiment, a method for preparing the self-activated metal-modified activated coke catalyst for desulfurization and denitrification according to the present invention is provided, the steps of which are as follows:

[0073] (1) Natural manganese carbonate ore was crushed and passed through a 200-mesh sieve to obtain manganese carbonate ore powder. The main components and mass content of the natural manganese carbonate ore were: Mn 34.2%, Si 9.17%, Mg 5.32%, Al 2.75%, Fe 2.52%, and S 1.21%. The manganese carbonate ore powder and KOH were thoroughly mixed with coal powder that had passed through a 200-mesh sieve to obtain a mixture. Water and coal tar were added to the mixture and thoroughly mixed. Then, the mixture was extruded and molded using an extrusion molding machine and dried to obtain semi-coke particles with a diameter of 6 mm.

[0074] In this step, the amount of water added is controlled to be 10% of the mass of the mixture, and the amount of coal tar added is controlled to be 35% to 40% of the mass of the mixture. The manganese carbonate ore powder is mixed with the coal powder according to the ratio of manganese mass to coal powder mass of 15%. In this step, two sets of experiments are conducted, and the amount of KOH added in each set of experiments is controlled to be 1% and 3% of the mass of coal powder, respectively.

[0075] (2) Place the semi-coke particles in a tubular furnace, seal the tubular furnace, raise the temperature of the tubular furnace to 800℃ at a heating rate of 5-20℃ / min, and hold at this temperature for 2 hours for activation treatment. During the heating and holding process, control the pressure in the tubular furnace cavity to maintain at 300±50Pa through the control valve of the tubular furnace. After the holding is completed, cool naturally to room temperature to obtain the activated coke catalyst for desulfurization and denitrification.

[0076] The activated coke catalysts for desulfurization and denitrification prepared by adding 1% and 3% coal powder by mass in step (1) are respectively denoted as E1 and E2.

[0077] E1 and E2 prepared in this example, and B2 prepared in Example 2, were used in an NH3-SCR reaction to test their denitrification activity. The test conditions were the same as in Example 1. The denitrification performance of E1, E2, and B2, i.e., the change curves of NO conversion rate over time when E1, E2, and B2 were used in the denitrification reaction, are shown in the figure below. Figure 9 As shown in Figure (a), the denitrification performance of E1 and E2 was enhanced compared to B2. The desulfurization performance of E1 and E2 prepared in this embodiment was tested under the same conditions as in Example 1. The desulfurization breakthrough curves of E1 and E2 are shown below. Figure 9 As shown in Figure (b), the sulfur capacities of E1 and E2 are 86.7 mg / g and 105.1 mg / g, respectively. The sulfur capacities of E1 and E2 are significantly higher than those of B2.

[0078] The nitrogen adsorption-desorption curves of E1, E2, and B2 are as follows: Figure 10 As shown, by Figure 10 It can be seen that the specific surface area S of E1 and E2 BET 446m respectively 2 / g and 459m 2 / g, relative to B2, the specific surface area S of E1 and E2 BET There has been a significant increase.

[0079] Example 6

[0080] In this embodiment, a method for preparing the self-activated metal-modified activated coke catalyst for desulfurization and denitrification according to the present invention is provided, the steps of which are as follows:

[0081] (1) Cobalt carbonate powder passing through a 200-mesh sieve and coal powder passing through a 200-mesh sieve are thoroughly mixed to obtain a mixture. A 3wt% sulfuric acid aqueous solution and coal tar are added to the mixture and thoroughly mixed. Then, the mixture is extruded and dried using an extrusion molding machine to obtain semi-coke particles with a diameter of 6mm.

[0082] In this step, the amount of sulfuric acid aqueous solution added is controlled to be 10% of the mass of the mixture, the amount of coal tar added is controlled to be 40% of the mass of the mixture, and cobalt carbonate powder is mixed with coal powder at a ratio of 15% of the mass of cobalt to the mass of coal powder.

[0083] (2) Place the semi-coke particles in a tubular furnace, seal the tubular furnace, raise the temperature of the tubular furnace to 800℃ at a heating rate of 5-20℃ / min, and hold at this temperature for 2 hours for activation treatment. During the heating and holding process, control the pressure in the tubular furnace cavity to maintain at 300±50Pa through the control valve of the tubular furnace. After the holding is completed, cool naturally to room temperature to obtain the activated coke catalyst for desulfurization and denitrification.

[0084] Example 7

[0085] The operation of this embodiment is basically the same as that of embodiment 6, except that: cobalt carbonate powder is replaced with copper carbonate powder, and copper carbonate powder is mixed with coal powder at a ratio of 15% of the mass of copper to the mass of coal powder.

[0086] Example 8

[0087] The operation of this embodiment is basically the same as that of embodiment 6, except that: cobalt carbonate powder is replaced with iron carbonate powder, and iron carbonate powder is mixed with coal powder at a ratio of 15% of the mass of iron to the mass of coal powder.

[0088] The three activated coke catalysts for desulfurization and denitrification prepared in Examples 6-8 were used in the NH3-SCR reaction to test their denitrification activity, under the same test conditions as in Example 1. The denitrification performance of the activated coke catalysts for desulfurization and denitrification prepared in Examples 6-8 is as follows: Figure 11 As shown in the figure.

[0089] Example 9

[0090] In this embodiment, a method for preparing the self-activated metal-modified activated coke catalyst for desulfurization and denitrification according to the present invention is provided, the steps of which are as follows:

[0091] (1) Natural manganese carbonate ore was crushed and passed through a 200-mesh sieve to obtain manganese carbonate ore powder. The main components and mass content of the natural manganese carbonate ore were: Mn 34.2%, Si 9.17%, Mg 5.32%, Al 2.75%, Fe 2.52%, and S 1.21%. The manganese carbonate ore powder and coal powder that had passed through a 200-mesh sieve were thoroughly mixed to obtain a mixture. A 5wt% sulfuric acid aqueous solution and coal tar were added to the mixture and thoroughly mixed. Then, the mixture was extruded and molded using an extrusion molding machine and dried to obtain semi-coke particles with a diameter of 6 mm.

[0092] In this step, the amount of sulfuric acid aqueous solution added is controlled to be 5% of the mass of the mixture; in this step, the amount of coal tar added is controlled to be 40% of the mass of the mixture, and manganese carbonate ore powder is mixed with coal powder according to the ratio of manganese mass to coal powder mass of 20%.

[0093] (2) Place the semi-coke particles in a tubular furnace, seal the tubular furnace, raise the temperature of the tubular furnace to 1000℃ at a heating rate of 5~20℃ / min, and hold at this temperature for 1h for activation treatment. During the heating and holding process, control the pressure in the tubular furnace cavity to maintain at 350±50Pa through the control valve of the tubular furnace. After the holding is completed, cool naturally to room temperature to obtain the activated coke catalyst for desulfurization and denitrification.

[0094] Example 10

[0095] In this embodiment, a method for preparing the self-activated metal-modified activated coke catalyst for desulfurization and denitrification according to the present invention is provided, the steps of which are as follows:

[0096] (1) Natural manganese carbonate ore was crushed and passed through a 200-mesh sieve to obtain manganese carbonate ore powder. The main components and mass content of the natural manganese carbonate ore were: Mn 34.2%, Si 9.17%, Mg 5.32%, Al 2.75%, Fe 2.52%, and S 1.21%. The manganese carbonate ore powder and coal powder that had passed through a 200-mesh sieve were thoroughly mixed to obtain a mixture. A 2wt% sulfuric acid aqueous solution and coal tar were added to the mixture and thoroughly mixed. Then, the mixture was extruded and molded using an extrusion molding machine and dried to obtain semi-coke particles with a diameter of 6 mm.

[0097] In this step, the amount of sulfuric acid aqueous solution added is controlled to be 15% of the mass of the mixture; in this step, the amount of coal tar added is controlled to be 35% of the mass of the mixture, and manganese carbonate ore powder is mixed with coal powder according to the ratio of manganese mass to coal powder mass of 30%.

[0098] (2) Place the semi-coke particles in a tubular furnace, seal the tubular furnace, raise the temperature of the tubular furnace to 900℃ at a heating rate of 5-20℃ / min, and hold at this temperature for 3 hours for activation treatment. During the heating and holding process, control the pressure in the tubular furnace cavity to maintain at 250±50Pa through the control valve of the tubular furnace. After the holding is completed, cool naturally to room temperature to obtain the activated coke catalyst for desulfurization and denitrification.

Claims

1. A method for preparing a self-activated metal-modified activated coke catalyst for desulfurization and denitrification, characterized in that, Includes the following steps: (1) Mix carbonate powder with coal powder thoroughly, and control the amount of carbonate powder added so that the mass of transition metal reaches at least 15% of the mass of coal powder to obtain a mixture. Mix the mixture with water or sulfuric acid aqueous solution and binder thoroughly, then extrude and dry to obtain a molded material. The carbonate powder is at least one of transition metal carbonate powder and natural ore powder containing transition metal carbonate, wherein the transition metal is manganese, cobalt, copper or iron, and the natural ore containing transition metal carbonate is manganese carbonate ore, wherein the manganese carbonate ore contains at least 40 wt% manganese carbonate. (2) Place the molding material in the reactor, seal the reactor, raise the temperature of the reactor to 800~1000 ℃ and keep it at this temperature for 1~3 h for activation treatment. During the heating and holding process, the pressure in the furnace cavity is controlled by the control valve of the reactor to be at a slight positive pressure of no more than 1000 Pa. During the activation process, the coal powder in the molding material is carbonized, the carbonate of the transition metal is decomposed to produce carbon dioxide and oxides of the transition metal. The carbon dioxide produced by the decomposition acts as an activator to self-activate the activated coke under the slight positive pressure condition. After the holding is completed, the activated coke catalyst for desulfurization and denitrification is obtained.

2. The preparation method of the self-activated metal-modified activated coke catalyst for desulfurization and denitrification according to claim 1, characterized in that, In step (1), the amount of water or sulfuric acid aqueous solution added is controlled to be 5% to 15% of the coal powder mass, and the amount of binder added is controlled to be 35% to 40% of the coal powder mass.

3. The method for preparing the self-activated metal-modified activated coke catalyst for desulfurization and denitrification according to claim 1 or 2, characterized in that, The concentration of the sulfuric acid aqueous solution is 2 wt% to 5 wt%.

4. The method for preparing the self-activated metal-modified activated coke catalyst for desulfurization and denitrification according to claim 1 or 2, characterized in that, Step (1) When preparing the mixture, a chemical activator is added. The carbonate powder, physical activator and coal powder are fully mixed to obtain the mixture. The chemical activator is sodium hydroxide, potassium hydroxide or phosphoric acid.

5. The preparation method of the self-activated metal-modified activated coke catalyst for desulfurization and denitrification according to claim 4, characterized in that, The amount of the chemical activator added is 1% to 5% of the coal powder mass.

6. The method for preparing the self-activated metal-modified activated coke catalyst for desulfurization and denitrification according to claim 1 or 2, characterized in that, Step (2) The pressure inside the furnace chamber is controlled by the control valve of the reactor to maintain it at 200~400 Pa.

7. The method for preparing the self-activated metal-modified activated coke catalyst for desulfurization and denitrification according to claim 1 or 2, characterized in that, In step (1), the amount of carbonate powder added is controlled so that the mass of the transition metal is 15% to 30% of the mass of the coal powder.

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