One for propane and NO x Synergistic removal catalyst and its preparation method and application

Abstract

The present invention provides a catalyst for the synergistic removal of propane and NOx, as well as its preparation method and application, belonging to the field of catalyst technology. The catalyst comprises a NiMnX composite metal oxide; wherein X is one or more of Ti, Ce, Nb, or V. The preparation method comprises dissolving acetates of manganese and nickel in a mixed alcohol solution to obtain solution A; dissolving oxalic acid in a mixed alcohol solution to obtain solution B; dissolving a metal salt of X in ethanol to form solution C; adding solution B to solution A and stirring to obtain a mixed solution D; adding solution C to the mixed solution D, stirring, centrifuging, drying, and calcining to obtain a catalyst. The catalyst is used for the synergistic removal of propane and NOx in a temperature range of 200-250°C. The catalyst preparation method is simple, inexpensive, pollution-free, and reduces the actual cost of industrial equipment, which is conducive to industrial production. The catalyst has good low-temperature activity for the synergistic removal of propane and NOx.

Description

Technical Field

[0001] The present invention belongs to the technical field of catalysts, and in particular relates to a catalyst for synergistic removal of propane and NOx, and a preparation method and application thereof. Background Art

[0002] Currently, air pollution control is gradually shifting from focusing primarily on the power industry to comprehensive control of key industries such as power, steel, building materials, and chemicals, as well as non-road mobile sources. The shift is also progressing from controlling conventional pollutants (PM, SO2, NOx) to jointly controlling conventional and unconventional pollutants (SO3, PM2.5, heavy metals such as Hg, and VOCs). Furthermore, the shift is moving from the efficient removal of a single pollutant at the end of the process to a new concept of efficient, coordinated removal of multiple pollutants. For example, industries such as shipping, coking, steel, and chemicals often emit PM, NOx, and VOCs, which pose new requirements for pollutant emission control.

[0003] Currently, NH3-SCR (using NH3 as a reducing agent for the selective catalytic reduction of NOx to N2) is the most effective technology for NOx removal, and catalytic oxidation is one of the most effective methods for VOC removal. Therefore, combining these two technologies has the potential to simultaneously remove VOCs and NOx. Finding a catalyst that is compatible with both denitrification and VOC oxidation is urgently needed.

[0004] In view of this, the present invention is proposed. Summary of the Invention

[0005] The object of the present invention is to provide a catalyst for the synergistic removal of propane and NOx, and a preparation method and application thereof, in order to solve the above-mentioned problems.

[0006] In order to achieve the above objectives, the present invention adopts the following technical solutions:

[0007] The present invention provides a catalyst for the coordinated removal of propane and NOx. The catalyst comprises a NiMnX composite metal oxide; X is one or more of Ti, Ce, Nb or V.

[0008] The atomic molar ratio of Mn to Ni is 1-3:1; the atomic molar ratio of X to Mn is 1:2-5.

[0009] The X includes Ce or a combination of Ce and Y, and the Y is one or more of Ti, Nb or V.

[0010] The present invention also provides a method for preparing the catalyst, comprising the following steps:

[0011] S1: dissolving manganese and nickel acetates in a mixed alcohol solution to obtain solution A.

[0012] Preferably, the manganese acetate is manganese acetate tetrahydrate, and the nickel acetate is nickel acetate tetrahydrate;

[0013] Furthermore, the atomic molar ratio of Mn to Ni in the solution A is 1-3:1;

[0014] Furthermore, the mixed alcohol comprises ethylene glycol and ethanol in a mass ratio of 1:2-4.

[0015] S2: Dissolve oxalic acid in the mixed alcohol solution to obtain solution B.

[0016] S3: Dissolve the metal salt of X in ethanol to form solution C.

[0017] Preferably, the metal salt of X includes cerium acetate or a mixed salt of cerium acetate and a salt of Y.

[0018] Furthermore, the salt of Y includes one or more of butyl titanate, niobium oxalate and ammonium metavanadate.

[0019] The NiMnX composite metal catalyst has good stability for propane oxidation and also has excellent sulfur and water resistance.

[0020] Furthermore, the atomic molar ratio of X to Mn is 1:2-5.

[0021] S4: adding solution B to solution A and stirring to obtain a mixed solution D, and adding solution C to the mixed solution D and stirring.

[0022] Preferably, when solution C is added to the mixed solution D, water is added at the same time. It is proven that water and alcohol can better disperse the solute (ie, active substance) in the mixed alcohol during the co-dissolution process.

[0023] S5: centrifuge, dry and calcine the product obtained in S4 to obtain.

[0024] Preferably, the drying is divided into primary drying and secondary drying. The primary drying temperature is 70-100°C for 15-24 hours, and the secondary drying temperature is 170-200°C for 30-120 minutes. After the secondary drying, the mixed alcohol and water are both dried and evaporated, and the active substance is precipitated more uniformly than in the primary drying.

[0025] The calcination temperature is 300-400°C and the calcination time is 2-4h;

[0026] Preferably, the heating rate of the calcination is 3-7°C / min;

[0027] Preferably, the calcination is performed under air atmosphere.

[0028] The present invention also provides an application of the catalyst, characterized in that the temperature range of the catalyst for synergistic removal of propane and NOx is 200-250°C.

[0029] Preferably, the temperature range of the catalyst for the synergistic removal of propane and NOx is 215-250°C.

[0030] More preferably, the temperature range of the catalyst for the synergistic removal of propane and NOx is 230-250°C.

[0031] Compared with existing technologies, the present invention, through the selection and combination of composite metal oxides, followed by co-dissolution and double drying, produces a catalyst for the synergistic removal of propane and NOx. The catalyst exhibits excellent sulfur and water resistance, good stability for propane oxidation, and excellent low-temperature activity for the synergistic removal of propane and NOx. The NOx conversion rate can reach over 80% within the temperature range of 100-250°C, and the propane conversion rate can reach 90% at 210°C. Furthermore, the preparation method of the present invention is simple, inexpensive, and pollution-free, reducing actual industrial equipment costs and facilitating industrial production. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] In order to more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the specific embodiments or the description of the prior art. Obviously, the drawings described below are some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0033] Figure 1 NiMn2Ce prepared in Examples 1-6 and Comparative Example 1 0.5 O x 、NiMn2Ce 0.5 O x 、NiMn2TiO x 、NiMn2NbO x 、NiMn2VO x 、NiMn2TiCe 0.5 O x , NiMn2O4 catalyst for propane and NO x Propane conversion in the evaluation of synergistic removal activity;

[0034] Figure 2 NiMn2Ce prepared in Examples 1-6 and Comparative Example 1 0.5 O x 、NiMn2Ce 0.5 O x、NiMn2TiO x 、NiMn2NbO x 、NiMn2VO x 、NiMn2TiCe 0.5 O x , NiMn2O4 catalyst for propane and NO x Evaluation of synergistic removal of NO x conversion rate;

[0035] Figure 3 NiMn2Ce prepared in Example 1 0.5 O x The catalyst was tested for propane oxidation stability according to the evaluation conditions of Test Example 1;

[0036] Figure 4 NiMn2Ce prepared in Example 1 0.5 O x The catalyst was tested for its water resistance to propane oxidation according to the evaluation conditions of Test Example 2;

[0037] Figure 5 NiMn2Ce prepared in Example 1 0.5 O x The catalyst was tested for its sulfur resistance in propane oxidation according to the evaluation conditions of Test Example 3. DETAILED DESCRIPTION

[0038] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.

[0039] In the present invention, any unspecified ratio of substances should be understood as an arbitrary ratio; any unspecified unit of the ratio of substances should be understood as a mass ratio.

[0040] Example 1

[0041] A catalyst for the synergistic removal of propane and NOx, comprising NiMn2Ce 0.5 O x , and its preparation method is as follows:

[0042] S1: Take 5.0 g of manganese acetate tetrahydrate and 2.5 g of nickel acetate tetrahydrate, add 200 mL of ethanol and 100 mL of ethylene glycol, and stir at room temperature to form solution A.

[0043] S2: Take 5.0 g of oxalic acid, add 40 mL of ethanol and 10 mL of ethylene glycol, and stir to form solution B.

[0044] S3: Take 1.5 g of cerium acetate, add 25 mL of ethanol, and stir to dissolve to obtain solution C.

[0045] S4: Solution B was added to solution A, and the mixture was stirred at room temperature for 0.5 h to obtain a mixed solution D. Solution C was added to the mixed solution D, and the mixture was stirred for 0.5 h.

[0046] S5: The precipitate was collected by centrifugation and dried at 90 °C for 15 h. The S4 product was calcined at 360 °C for 3 h in air atmosphere with a heating rate of 7 °C / min. Finally, NiMn2Ce was obtained at room temperature. 0.5 O x catalyst.

[0047] The catalyst prepared by S5 was loaded into a fixed bed reactor, the reaction temperature was 100-250 ° C, and simulated flue gas at normal pressure with 500ppm C3H8, 500ppm NO, 500ppm NH3, O2 concentration of 5%, and balance gas N2 was introduced. The reaction space velocity was controlled at 30000h -1 .

[0048] Test results: The conversion rate of propane at 250℃ is 100% and NO x The conversion rate was 97%.

[0049] Example 2

[0050] A catalyst for the synergistic removal of propane and NOx, comprising NiMn2Ce 0.5 O x , and its preparation method is as follows:

[0051] S1: Take 5.0 g of manganese acetate tetrahydrate and 2.5 g of nickel acetate tetrahydrate, add 200 mL of ethanol and 100 mL of ethylene glycol, and stir at room temperature to form solution A.

[0052] S2: Take 5.0 g of oxalic acid, add 40 mL of ethanol and 10 mL of ethylene glycol, and stir to form solution B.

[0053] S3: Take 1.5 g of cerium acetate, add 25 mL of ethanol, and stir to dissolve to obtain solution C.

[0054] S4: Solution B was added to solution A, and the mixture was stirred at room temperature for 0.5 h to obtain a mixed solution D. Solution C was added to the mixed solution D, and 10 mL of deionized water was added at the same time, and the mixture was stirred for 0.5 h.

[0055] S5: The precipitate was collected by centrifugation, dried at 90 °C for 15 h, and then dried at 100 °C for 60 min. The S4 product was calcined at 360 °C for 3 h in air atmosphere with a heating rate of 7 °C / min. Finally, NiMn2Ce was obtained at room temperature. 0.5 O x catalyst.

[0056] The catalyst prepared by S5 was loaded into a fixed bed reactor, the reaction temperature was 100-250 ° C, and simulated flue gas at normal pressure with 500ppm C3H8, 500ppm NO, 500ppm NH3, O2 concentration of 5%, and balance gas N2 was introduced. The reaction space velocity was controlled at 30000h -1 .

[0057] Test results: The conversion rate of propane at 230℃ and 250℃ is 100%, and the conversion rate of NO x The conversion rates were 99% and 98%, respectively.

[0058] Example 3

[0059] A catalyst for the synergistic removal of propane and NOx, comprising NiMn2TiO x , and its preparation method is as follows:

[0060] S1: Take 5.0 g of manganese acetate tetrahydrate and 2.5 g of nickel acetate tetrahydrate, add 200 mL of ethanol and 100 mL of ethylene glycol, and stir at room temperature to form solution A.

[0061] S2: Take 5.0 g of oxalic acid, add 40 mL of ethanol and 10 mL of ethylene glycol, and stir to form solution B.

[0062] S3: Take 3.5 g of butyl titanate, add 50 mL of ethanol, and stir to dissolve to obtain solution C.

[0063] S4: Solution B was added to solution A, and the mixture was stirred at room temperature for 0.5 h to obtain a mixed solution D. Solution C was added to the mixed solution D, and the mixture was stirred for 0.5 h.

[0064] S5: The precipitate was collected by centrifugation and dried at 90 °C for 15 h. The S4 product was calcined at 360 °C for 3 h in air atmosphere with a heating rate of 7 °C / min. Finally, NiMn2TiO was obtained at room temperature. x catalyst.

[0065] The catalyst prepared by S5 was loaded into a fixed bed reactor, the reaction temperature was 100-250 ° C, and simulated flue gas at normal pressure with 500ppm C3H8, 500ppm NO, 500ppm NH3, O2 concentration of 5%, and balance gas N2 was introduced. The reaction space velocity was controlled at 30000h -1 .

[0066] Test results: The conversion rate of propane at 250℃ is 84% and NO x The conversion rate was 83%.

[0067] Example 4

[0068] A catalyst for the synergistic removal of propane and NOx, comprising NiMn2NbO x , and its preparation method is as follows:

[0069] S1: Take 5.0 g of manganese acetate tetrahydrate and 2.5 g of nickel acetate tetrahydrate, add 200 mL of ethanol and 100 mL of ethylene glycol, and stir at room temperature to form solution A.

[0070] S2: Take 5.0 g of oxalic acid, add 40 mL of ethanol and 10 mL of ethylene glycol, and stir to form solution B.

[0071] S3: Take 5.5 g of niobium oxalate, add 50 mL of ethanol, and stir to dissolve to obtain solution C.

[0072] S4: Solution B was added to solution A, and the mixture was stirred at room temperature for 0.5 h to obtain a mixed solution D. Solution C was added to the mixed solution D, and the mixture was stirred for 0.5 h.

[0073] S5: The precipitate was collected by centrifugation and dried at 90 °C for 15 h. The S4 product was calcined at 360 °C for 3 h in air atmosphere with a heating rate of 7 °C / min. Finally, NiMn2NbO was obtained at room temperature. x catalyst.

[0074] The catalyst prepared by S5 was loaded into a fixed bed reactor, the reaction temperature was 100-250 ° C, and simulated flue gas at normal pressure with 500ppm C3H8, 500ppm NO, 500ppm NH3, O2 concentration of 5%, and balance gas N2 was introduced. The reaction space velocity was controlled at 30000h -1 .

[0075] Test results: The conversion rate of propane at 250℃ is 40% and NO x The conversion rate was 98%.

[0076] Example 5

[0077] A catalyst for the coordinated removal of propane and NOx, comprising NiMn2VO x , and its preparation method is as follows:

[0078] S1: Take 5.0 g of manganese acetate tetrahydrate and 2.5 g of nickel acetate tetrahydrate, add 200 mL of ethanol and 100 mL of ethylene glycol, and stir at room temperature to form solution A.

[0079] S2: Take 5.0 g of oxalic acid, add 40 mL of ethanol and 10 mL of ethylene glycol, and stir to form solution B.

[0080] S3: Take 1.2 g of ammonium metavanadate, add 50 mL of ethanol, and stir to dissolve to obtain solution C.

[0081] S4: Solution B was added to solution A, and the mixture was stirred at room temperature for 0.5 h to obtain a mixed solution D. Solution C was added to the mixed solution D, and the mixture was stirred for 0.5 h.

[0082] S5: The precipitate was collected by centrifugation and dried at 90 °C for 15 h. The S4 product was calcined at 360 °C for 3 h in air atmosphere with a heating rate of 7 °C / min. Finally, NiMn2VO was obtained at room temperature. x catalyst.

[0083] The catalyst prepared by S5 was loaded into a fixed bed reactor, the reaction temperature was 100-250 ° C, and simulated flue gas at normal pressure with 500ppm C3H8, 500ppm NO, 500ppm NH3, O2 concentration of 5%, and balance gas N2 was introduced. The reaction space velocity was controlled at 30000h -1 .

[0084] Test results: The conversion rate of propane at 250℃ is 88% and NO x The conversion rate was 83%.

[0085] Example 6

[0086] A catalyst for the coordinated removal of propane and NOx, comprising NiMn2TiCe 0.5 O x , and its preparation method is as follows:

[0087] S1: Take 5.0 g of manganese acetate tetrahydrate and 2.5 g of nickel acetate tetrahydrate, add 200 mL of ethanol and 100 mL of ethylene glycol, and stir at room temperature to form solution A.

[0088] S2: Take 5.0 g of oxalic acid, add 40 mL of ethanol and 10 mL of ethylene glycol, and stir to form solution B.

[0089] S3: Take 3.5 g of butyl titanate and 1.5 g of cerium acetate, add 50 mL of ethanol, and stir to dissolve to obtain solution C.

[0090] S4: Solution B was added to solution A, and the mixture was stirred at room temperature for 0.5 h to obtain a mixed solution D. Solution C was added to the mixed solution D, and the mixture was stirred for 0.5 h.

[0091] S5: The precipitate was collected by centrifugation and dried at 90 °C for 15 h. The S4 product was calcined at 360 °C for 3 h in air atmosphere with a heating rate of 7 °C / min. Finally, NiMn2TiCe was obtained at room temperature. 0.5 O x catalyst.

[0092] The catalyst prepared by S5 was loaded into a fixed bed reactor, the reaction temperature was 100-250 ° C, and simulated flue gas at normal pressure with 500ppm C3H8, 500ppm NO, 500ppm NH3, O2 concentration of 5%, and balance gas N2 was introduced. The reaction space velocity was controlled at 30000h -1 .

[0093] Test results: The conversion rate of propane at 250℃ is 100% and NO x The conversion rate was 98%.

[0094] Test Example 1

[0095] The difference between this test example and Example 1 is that the catalyst was reacted at 250° C. for 60 h, the simulated flue gas contained 500 ppm C 3 H 8 , 5% O 2 concentration, and the balance gas was N 2 .

[0096] The test results are as follows Figure 3 As shown, the conversion of propane at 250°C is 100% in steady state.

[0097] Test Example 2

[0098] The difference between this test example and Example 1 is that 5% water was introduced into the catalyst at 230° C. and 250° C., respectively, and the simulated flue gas contained 500 ppm C 3 H 8 , 5% O 2 concentration, 5 vol.% H 2 O, and the balance gas was N 2 .

[0099] The test results are as follows Figure 4 As shown, the conversion rate of propane at 230° C. in a steady state after water is introduced is 68%, and the conversion rate of propane at 250° C. in a steady state after water is introduced is 93%.

[0100] Test Example 3

[0101] The difference between this test example and Example 1 is that 150 ppm SO2 is introduced into the catalyst at 300°C, the simulated flue gas contains 500 ppm C3H8, 5% O2 concentration, 150 ppm SO2, and the balance gas is N2.

[0102] The test results are as follows Figure 5 As shown, the propane conversion rate of the catalyst is above 80% within 6 hours after the introduction of SO2.

[0103] Comparative Example 1

[0104] A catalyst for the synergistic removal of propane and NOx, comprising NiMn2O4, and a preparation method thereof is as follows:

[0105] S1: Take 5.0 g of manganese acetate tetrahydrate and 2.5 g of nickel acetate tetrahydrate, add 200 mL of ethanol and 100 mL of ethylene glycol, and stir at room temperature to form solution A.

[0106] S2: Take 5.0 g of oxalic acid, add 40 mL of ethanol and 10 mL of ethylene glycol, and stir to form solution B.

[0107] S3: Add solution B to solution A and stir at room temperature for 0.5 h.

[0108] S4: The precipitate was collected by centrifugation and dried at 90°C for 15 h. The S3 product was calcined at 360°C for 3 h in air at a heating rate of 7°C / min. Finally, the NiMn2O4 catalyst was obtained at room temperature.

[0109] The catalyst prepared by S4 was loaded into a fixed bed reactor, the reaction temperature was 100-250 ° C, and simulated flue gas at normal pressure with 500ppm C3H8, 500ppm NO, 500ppm NH3, O2 concentration of 5%, and balance gas N2 was introduced. The reaction space velocity was controlled at 30000h -1 .

[0110] Test results: The conversion rate of propane at 250℃ is 98% and NO x The conversion rate was 90%.

[0111] Combine Figure 1 and Figure 2 It can be seen from Examples 1 and 6 that the catalyst doped with cerium has the best effect in synergistically removing propane and NOx, especially the catalyst doped with cerium and titanium in Example 6.

[0112] See Figure 1 and Figure 2 In Example 2, after adding water in step S4 and drying twice in step S5, the effect is better than that of Examples 1 and 6, especially the conversion rate of propane and NO at 230 ° C. x The conversion rate also reached a very high level.

[0113] As can be seen from Test Example 1, the propane conversion rate does not decrease when the catalyst is running for a long time. As can be seen from Test Examples 2 and 3, the catalyst also has good water and sulfur resistance.

[0114] Please note that the technical features of the above embodiments can be combined arbitrarily. In order to make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification. The above embodiments only express several implementation methods of the present application. The description is relatively specific and detailed, but it cannot be understood as a limitation on the scope of the invention patent. It should be pointed out that for ordinary technicians in this field, without departing from the concept of this application, several variations and improvements can be made, which all fall within the scope of protection of this application. Therefore, the scope of protection of the patent in this application shall be based on the attached claims.

Claims

1. A catalyst for the synergistic removal of propane and NOx, characterized in that: The catalyst comprises a NiMnX composite metal oxide; X comprises Ce or a combination of Ce and Y, and Y is one or more of Ti, Nb or V; The atomic molar ratio of Mn to Ni is 1-3:1; the atomic molar ratio of X to Mn is 1:2-5; The preparation method of the catalyst comprises the following steps: S1: dissolving manganese and nickel acetates in a mixed alcohol solution to obtain solution A; S2: dissolving oxalic acid in a mixed alcohol solution to obtain solution B; S3: dissolving the metal salt of X in ethanol to form solution C; S4: adding solution B to solution A and stirring to obtain a mixed solution D, and adding solution C to the mixed solution D and stirring; S5: centrifuging, drying, and calcining the product obtained in S4 to obtain; In step S4, when solution C is added to the mixed solution D, water is added at the same time; In step S5, the drying is divided into primary drying and secondary drying. The primary drying temperature is 70-100° C. and the time is 15-24 hours; the secondary drying temperature is 170-200° C. and the time is 30-120 minutes.

2. The catalyst according to claim 1, characterized in that In step S3, the metal salt of X includes cerium acetate or a mixed salt of cerium acetate and a salt of Y; The salt of Y includes one or more of butyl titanate, niobium oxalate and ammonium metavanadate.

3. The catalyst according to claim 1, characterized in that Step S1 satisfies one or more of the following conditions: a. the manganese acetate is manganese acetate tetrahydrate, and the nickel acetate is nickel acetate tetrahydrate; b. The atomic molar ratio of Mn to Ni in the solution A is 1-3:1; c. The mixed alcohol comprises ethylene glycol and ethanol in a mass ratio of 1:2-4.

4. The catalyst according to claim 1, characterized in that In step S5, the calcination temperature is 300-400° C., and the calcination time is 2-4 h.

5. The catalyst according to claim 1, characterized in that The heating rate of the calcination is 3-7°C / min.

6. The catalyst according to claim 1, characterized in that The calcination is carried out under an air atmosphere.

7. Use of the catalyst according to any one of claims 1 to 6, characterized in that: The temperature range of the catalyst for synergistic removal of propane and NOx is 200-250°C.

8. The use according to claim 7, characterized in that The temperature range of the catalyst for synergistic removal of propane and NOx is 215-250°C.

9. The use according to claim 8, characterized in that The temperature range of the catalyst for synergistic removal of propane and NOx is 230-250°C.

Images