Composite carbon monoxide combustion-supporting and denitration dual-effect catalyst and preparation method thereof

Abstract

The application discloses a composite carbon monoxide combustion-supporting and denitration double-effect catalyst and a preparation method thereof, and belongs to the technical field of petroleum refining. The double-effect catalyst is composed of a carrier and active components loaded on the carrier, wherein the carrier is an alumina carrier, and the active components are composite oxides of PdO and CuO. The preparation method of the double-effect catalyst comprises the following steps: preparing the carrier; preparing an impregnation solution composed of a soluble Pd salt solution and a soluble Cu salt solution; impregnating the carrier with the impregnation solution; and drying and calcining after impregnation to obtain the double-effect catalyst. The double-effect catalyst provided by the application can not only support combustion of CO but also remove NO x in a petroleum refining catalytic cracking process, thereby protecting equipment and reducing environmental pollution. The double-effect catalyst provided by the application has high activity and good stability, the CO conversion rate can reach more than 99%, and the NO x content can be reduced by more than 70%. The preparation method of the double-effect catalyst is simple and easy to implement.

Description

Technical Field

[0001] This invention belongs to the field of petroleum refining technology, specifically relating to a composite carbon monoxide combustion-supporting and denitrification dual-effect catalyst used in petroleum refining catalytic cracking process and its preparation method. Background Technology

[0002] Catalytic cracking is currently the most important secondary processing process in the petroleum refining industry. It is also the core technology for the transformation of heavy oil into light oil and an important means to improve the depth of crude oil processing and increase the yield of light oil. More than 80% of gasoline and more than 30% of diesel in my country come from the catalytic cracking process.

[0003] Traditional feedstocks for catalytic cracking are heavy distillate oils, primarily straight-run vacuum gas oil (VGO), and also include coking heavy gas oil (CGO). Due to the increasing demand for light oils and technological advancements, heavier oils have also been used as feedstocks for catalytic cracking in recent decades, such as vacuum residue, deasphalted vacuum residue, and hydrotreated heavy oil. These heavy and inferior oils have high carbon residue, high heavy metal content, and high sulfur, nitrogen, and heteroatom content. During the coking process in catalytic cracking, a large amount of CO is generated in the dense phase layer of the regenerator. Even with a high O2 content, it cannot be completely burned. If CO burns in the dilute phase region, it will cause tail combustion, damaging the equipment. Furthermore, the sulfur and nitrogen in the deposited coke will be oxidized to sulfur dioxide (SO4). X NO X As the flue gas is released into the atmosphere, it forms acid rain, causing serious pollution to the environment.

[0004] NO emitted from catalytic cracking regeneration flue gas X The content of gases (including NO, NO2, N2O, etc.) is relatively large. With increasingly stringent environmental protection laws, the issue of reducing pollution is becoming increasingly important. How to solve the problem of gaseous pollution generated during catalytic cracking is an important direction for the development of catalysts and additives.

[0005] Patent CN 105983404 discloses a catalytic cracking CO combustion improver, which consists of an active component loaded on a support. Based on the weight of the support, the loading amount of the active component on the support is 2-20 wt%, and the active component is a non-precious metal inorganic oxide with a certain amount of oxygen ion defects. The patent also provides a method for preparing the catalytic cracking CO combustion improver.

[0006] Patent CN 1450148 discloses a carbon monoxide combustion improver used in petroleum refining catalytic cracking units, its preparation method, and its uses. The active component is A. 1-x A' x B 1-y B'yO 3-δA complex of perovskite-type rare earth composite oxides and transition metal oxides with a structure of ·zB”O is disclosed. A is a rare earth element, A' is an alkaline earth metal element, and B, B' and B” are transition metal elements. x is 0 to 0.4, y is 0 to 1, z is 0 to 1, and δ is <0 to 0.3. A method for preparing a combustion improver is also disclosed.

[0007] Patent CN 1179463A discloses a carbon monoxide combustion improver, characterized in that the active component is platinum and palladium noble metal elements accounting for 0.005-0.2% of the weight of the combustion improver, and its carrier is silica-alumina containing 2.0-40% Y-type or ZSM-5 type zeolite, clay or a mixture thereof, and the carrier should be microspherical particles of 30-100μm, of which more than 90% of the particles have a size of 40-80μm. The preparation method is also disclosed.

[0008] While the additives provided by the above patents are very effective in promoting CO combustion, they are not ideal for removing NO. X The effect of this method is not obvious. Therefore, a method is proposed that can both promote CO combustion and remove NO. X Dual-effect catalysts that effectively address the environmental pollution problem of reducing emissions from refinery regeneration flue gas are a research hotspot in this field. Summary of the Invention

[0009] To address the problems of the prior art, this invention provides a composite carbon monoxide combustion-supporting and denitrification dual-effect catalyst used in petroleum refining catalytic cracking process and its preparation method.

[0010] To achieve the above objectives, the present invention adopts the following technical solution:

[0011] According to a first aspect of the present invention, a composite dual-effect catalyst for carbon monoxide combustion and denitrification is provided, the dual-effect catalyst comprising a support and an active component supported on the support, wherein the support is an alumina support and the active component is a composite oxide of PdO and CuO.

[0012] According to one embodiment of the present invention, the active component has the general formula PdO-xCuO, wherein x ranges from 0.2 to 3.5.

[0013] According to one embodiment of the present invention, the loading amount of the active component on the support is 0.06wt%-0.16wt%.

[0014] According to one embodiment of the present invention, the alumina support is one or more of boehmite, alumina trihydrate, alumina monohydrate, and amorphous aluminum hydroxide.

[0015] According to one embodiment of the present invention, the particle size distribution of the alumina support is greater than 85% and is between 30 and 120 μm.

[0016] According to one embodiment of the present invention, the alumina carrier is boehmite that has been mixed, dried and calcined.

[0017] According to a second aspect of the present invention, a method for preparing the above-mentioned composite carbon monoxide combustion-supporting and denitrification dual-effect catalyst is provided, comprising the following steps: preparing a support; preparing an impregnation solution composed of a soluble Pd salt solution and a soluble Cu salt solution; impregnating the support with the impregnation solution; and drying and calcining after impregnation to obtain the composite carbon monoxide combustion-supporting and denitrification dual-effect catalyst.

[0018] According to one embodiment of the present invention, the carrier is prepared by mixing, drying and calcining pseudoboehmite.

[0019] According to one embodiment of the present invention, neutralizing amine and ammonium metavanadate are added during the mixing process; the mixed carrier is dried at 80-100°C for 2-4 hours; and the dried carrier is calcined at 500-700°C for 2-6 hours.

[0020] According to one embodiment of the present invention, the mass ratio of neutralizing amine, ammonium metavanadate and pseudoboehmite is 1:1 to 7.5:18 to 95.

[0021] According to one embodiment of the present invention, the soluble Pd salt solution is a PdCl2 solution, and the soluble Cu salt solution is a CuCl2 solution.

[0022] According to one embodiment of the present invention, the concentrations of the PdCl2 solution and the CuCl2 solution are 0.001 to 0.02 mg / ml, respectively.

[0023] According to one embodiment of the present invention, the immersion time is 1 to 10 hours.

[0024] According to one embodiment of the present invention, the drying is carried out in two steps: in the first step, the temperature is raised to 60-80°C for 2 hours, kept at the temperature for 2-4 hours, and then cooled down to room temperature; in the second step, the temperature is raised to 110-120°C and kept at the temperature for 2-6 hours.

[0025] According to one embodiment of the present invention, the calcination is carried out at 400-600°C for 4-8 hours.

[0026] By adopting the above technical solution, the present invention has the following beneficial effects:

[0027] The dual-effect catalyst provided by this invention can both aid in the combustion of CO and remove NO during the catalytic cracking process of petroleum refining. x The effect is not only to protect equipment but also to reduce environmental pollution. The dual-effect catalyst provided by this invention has high activity, good stability, and a CO conversion rate of over 99%, while reducing NO...x The content decreases by more than 70%. Compared with Pt catalysts, the dual-effect catalyst provided by this invention has a wider range of raw material sources and a relatively lower cost.

[0028] The preparation method of the dual-effect catalyst provided by this invention is simple and easy to implement. Detailed Implementation

[0029] To make the objectives, technical solutions, and advantages of this invention clearer, the invention will be further described in detail below with reference to specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative and not intended to limit the invention.

[0030] Specific embodiments of the invention are disclosed herein as needed; however, it should be understood that the embodiments disclosed herein are merely examples of the invention that may be implemented in various alternative forms. In the following description, various operating parameters and components are described in several contemplated embodiments. These specific parameters and components are provided as examples only and are not intended to be limiting.

[0031] A first aspect of the present invention provides a composite dual-effect catalyst for carbon monoxide combustion and denitrification. This dual-effect catalyst comprises a support and an active component supported on the support. The support is an alumina support, and the active component is a composite oxide of PdO and CuO. The dual-effect catalyst of the present invention undergoes the following reactions during combustion and denitrification:

[0032] PdO + CO → Pd + CO2↑

[0033] CuO + CO → Cu + CO2↑

[0034] Pd + CO → Pd:CO, Pd + NO → Pd:NO

[0035] Cu + CO → Cu:CO, Cu + NO → Cu:NO

[0036] PdO+Pd:CO→2Pd+CO2, Pd:NO+CO→Pd+CO2↑+N2↑

[0037] CuO+Cu:CO→2Cu+CO2, Cu:NO+CO→Cu+CO2↑+N2↑

[0038] Pd or Cu have both lone pairs of electrons and empty orbitals, which can both accept and donate lone pairs of electrons, thus forming coordinate bonds with molecules such as CO and NO that have π-bond structures, thereby reducing the bond energy of CO and NO to some extent.

[0039] In some embodiments of the present invention, the general formula of the active component is PdO-xCuO, wherein x ranges from 0.2 to 3.5.

[0040] In some embodiments of the present invention, the loading of the active component on the support is 0.06 wt% to 0.16 wt%. Here, the loading is the percentage of the sum of the Pd content and the Cu content to the mass of the support.

[0041] In some embodiments of the present invention, the alumina support can be one or more of boehmite, alumina trihydrate, alumina monohydrate, and amorphous aluminum hydroxide. Preferably, boehmite is used as the support. Boehmite, also known as pseudo-monohydrate boehmite, is a type of aluminum hydroxide with fine particles, incomplete crystallization, and thin, wrinkled lamellar layers. In its aqueous state, it is a thixotropic gel with high specific surface area and large pore volume. When boehmite is used as a support, the large pore volume facilitates the diffusion of macromolecular compounds into the catalyst particles, while the high specific surface area facilitates the dispersion of active components, thereby improving the reaction performance of the catalyst.

[0042] In some embodiments of the present invention, the particle size distribution of the alumina support is between 30 and 120 μm, and is greater than 85%.

[0043] A second aspect of the present invention provides a method for preparing the above-mentioned composite carbon monoxide combustion-supporting and denitrification dual-effect catalyst, comprising the following steps: (1) preparing a support; (2) preparing an impregnation solution composed of a soluble Pd salt solution and a soluble Cu salt solution; (3) impregnating the support with the impregnation solution; (4) drying and calcining after impregnation to obtain the composite carbon monoxide combustion-supporting and denitrification dual-effect catalyst. The present invention uses a solution impregnation method to uniformly load the metal onto the support. Drying removes liquid water, and calcination makes the metal more firmly fixed on the support, preventing it from easily falling off.

[0044] In some embodiments of the present invention, step (1) of preparing the carrier includes: mixing boehmite with neutralizing amine and ammonium metavanadate, followed by drying and calcination to obtain the carrier. Ammonium metavanadate decomposes to generate vanadium pentoxide, which is acidic, and decomposes into oxygen and vanadium tetroxide at high temperature, which have strong oxidizing properties and can oxidize CO to CO2. Neutralizing amine is weakly alkaline and adjusts the pH value. During the mixing process, the mass ratio of neutralizing amine, ammonium metavanadate and boehmite is 1:1 to 7.5:18 to 95. The mixed carrier is dried at 80 to 100°C for 2-4 hours. The dried carrier is calcined at 500 to 700°C for 2-6 hours.

[0045] In some embodiments of the present invention, step (2) of preparing the impregnation solution composed of a soluble Pd salt solution and a soluble Cu salt solution includes: preparing a soluble Pd salt solution and a soluble Cu salt solution of a certain concentration; calculating the required volume of the soluble Pd salt solution and the soluble Cu salt solution according to the loading of the active component; and mixing the required volume of the soluble Pd salt solution and the soluble Cu salt solution to form the impregnation solution. Preferably, the soluble Pd salt solution is a PdCl2 solution, and the soluble Cu salt solution is a CuCl2 solution. Preferably, the concentrations of the PdCl2 solution and the CuCl2 solution are 0.001–0.02 mg / ml.

[0046] In some embodiments of the present invention, the immersion time in step (3) is 1 to 10 hours.

[0047] In some embodiments of the present invention, the drying in step (4) is carried out in two steps. In the first step, the temperature is raised to 60-80°C for 2 hours, kept at the temperature for 2-4 hours, and then cooled down to room temperature. In the second step, the temperature is raised to 110-120°C and kept at the temperature for 2-6 hours. The purpose of carrying out the drying in two steps is to avoid local overheating caused by drying in one step, which would affect the load-bearing effect.

[0048] In some embodiments of the present invention, the calcination in step (4) is carried out at 400-600°C for 4-8 hours.

[0049] The following are specific embodiments of the dual-effect catalyst and its preparation method according to the present invention. Unless otherwise stated, the raw materials, equipment, consumables, etc. used in the following embodiments can be obtained by conventional commercial means.

[0050]

Example 1

[0051] Preparation of dual-effect catalyst support: Neutralized amine, ammonium metavanadate and pseudoboehmite were added to a mixer in proportion and mixed. The mixing ratio, drying and calcination temperature are shown in Table 1. The pseudoboehmite has a particle size distribution of 30-120 μm and is greater than 85%.

[0052] Table 1. Parameters related to the preparation of dual-effect catalyst supports

[0053]

[0054]

[0055]

Example 2

[0056] Preparation of the dual-effect catalyst: PdCl2 solution and CuCl2 solution of a certain concentration were prepared. The volume of the solution was calculated according to the PdO-CuO loading. The carrier 1 was impregnated by impregnation method. After impregnation, the carrier was dried and then calcined in a muffle furnace. Specific parameters are shown in Table 2.

[0057] Table 2. Preparation parameters of dual-effect catalysts 1-1 to 1-5

[0058]

[0059]

Example 3

[0060] Preparation of the dual-effect catalyst: PdCl2 solution and CuCl2 solution of a certain concentration were prepared. The volume of the solution was calculated according to the PdO-CuO loading. The carrier 2 was impregnated by impregnation. After impregnation, the carrier was dried and then calcined in a muffle furnace. Specific parameters are shown in Table 3.

[0061] Table 3. Preparation parameters of dual-effect catalysts 2-1 to 2-5

[0062]

[0063]

[0064]

Example 4

[0065] Preparation of the dual-effect catalyst: PdCl2 solution and CuCl2 solution of a certain concentration were prepared. The volume of the solution was calculated according to the PdO-CuO loading. The carrier 3 was impregnated by impregnation method. After impregnation, the carrier was dried and finally transferred to a muffle furnace for calcination. Specific parameters are shown in Table 4.

[0066] Table 4. Preparation parameters of dual-effect catalysts 3-1 to 3-5

[0067]

[0068]

Example 5

[0069] Preparation of the dual-effect catalyst: PdCl2 solution and CuCl2 solution of a certain concentration were prepared. The volume of the solution was calculated according to the PdO-CuO loading. The carrier 4 was impregnated by impregnation. After impregnation, the carrier was dried and then calcined in a muffle furnace. Specific parameters are shown in Table 5.

[0070] Table 5. Preparation parameters of dual-effect catalysts 4-1 to 4-5

[0071]

[0072]

Example 6

[0073] Preparation of the dual-effect catalyst: PdCl2 solution and CuCl2 solution of a certain concentration were prepared. The volume of the solution was calculated according to the PdO-CuO loading. The carrier 5 was impregnated by impregnation method. After impregnation, the carrier was dried and then calcined in a muffle furnace. Specific parameters are shown in Table 6.

[0074] Table 6. Preparation parameters of dual-effect catalysts 5-1 to 5-5

[0075]

[0076]

Example 7

[0077] Evaluation of dual-effect catalysts: 10ml fixed-bed evaluation apparatus, reactor quartz tube, both sides packed with quartz sand, standard gas with CO content of 5% (vt), NO x The gas composition was 5% (vt), O2 content was 10%, N2 content was 80%, the inlet flow rate was 100 ml / min, the reaction temperature was 680℃, the reaction pressure was atmospheric pressure, and the exhaust gas was analyzed for CO and NO using gas chromatography. x The content and evaluation results are shown in Table 7.

[0078] Table 7 Evaluation Results of Dual-Effect Catalysts

[0079]

[0080]

[0081] As can be seen from the table above, the dual-effect catalyst of this invention has high activity, with a CO conversion rate of over 99% and NO... x With a content reduction of over 70%, the dual-effect catalyst of this invention can be used in the regenerator of a catalytic cracking unit, which can not only protect the equipment but also reduce environmental pollution.

[0082] The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the specific details in the above embodiments. Within the scope of the technical concept of the present invention, various simple modifications can be made to the technical solution of the present invention, and these simple modifications all fall within the protection scope of the present invention.

[0083] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not describe the various possible combinations separately.

[0084] Furthermore, various different embodiments of the present invention can be combined in any way, as long as they do not violate the spirit of the present invention, they should also be regarded as the content disclosed by the present invention.

Claims

1. A composite dual-effect catalyst for carbon monoxide combustion assistance and denitrification, characterized in that, The product consists of a carrier and an active component loaded on the carrier. The carrier is a pseudoboehmite carrier that has been mixed with neutralized amine and ammonium metavanadate, dried, and calcined. The particle size distribution of the pseudoboehmite carrier is greater than 85% in the range of 30 to 120 μm. The active component is a composite oxide of PdO and CuO, with the general formula PdO-xCuO, where x ranges from 0.2 to 3.

5. The loading amount of the active component on the carrier is 0.06 wt% to 0.16 wt%.

2. The preparation method of the composite carbon monoxide combustion-supporting and denitrification dual-effect catalyst according to claim 1, characterized in that, Includes the following steps: The carrier was prepared by mixing boehmite with neutralizing amine and ammonium metavanadate, followed by drying and calcination. Prepare an impregnation solution consisting of a soluble Pd salt solution and a soluble Cu salt solution; The carrier is impregnated with the impregnation solution; After impregnation, the catalyst is dried and calcined to obtain the composite carbon monoxide combustion-supporting and denitrification dual-effect catalyst.

3. The preparation method of the composite carbon monoxide combustion-supporting and denitrification dual-effect catalyst according to claim 2, characterized in that, During the carrier preparation process, the drying temperature is 80-100℃ and the drying time is 2-4h, the calcination temperature is 500-700℃ and the calcination time is 2-6h.

4. The preparation method of the composite carbon monoxide combustion-supporting and denitrification dual-effect catalyst according to claim 2, characterized in that, The mass ratio of neutralizing amine, ammonium metavanadate, and pseudoboehmite is 1:1 to 7.5:18 to 95.

5. The preparation method of the composite carbon monoxide combustion-supporting and denitrification dual-effect catalyst according to claim 2, characterized in that, The soluble Pd salt solution is a PdCl2 solution, and the soluble Cu salt solution is a CuCl2 solution.

6. The preparation method of the composite carbon monoxide combustion-supporting and denitrification dual-effect catalyst according to claim 5, characterized in that, The concentrations of the PdCl2 solution and the CuCl2 solution were 0.001–0.02 mg / ml, respectively.

7. The preparation method of the composite carbon monoxide combustion-supporting and denitrification dual-effect catalyst according to claim 2, characterized in that, The soaking time is 1 to 10 hours.

8. The preparation method of the composite carbon monoxide combustion-supporting and denitrification dual-effect catalyst according to claim 2, characterized in that, The drying process is carried out in two steps. In the first step, the temperature is raised to 60-80℃ for 2 hours, kept at the same temperature for 2-4 hours, and then cooled down to room temperature. In the second step, the temperature is raised to 110-120℃ and kept at the same temperature for 2-6 hours.

9. The preparation method of the composite carbon monoxide combustion-supporting and denitrification dual-effect catalyst according to claim 2, characterized in that, After impregnation and drying, the roasting is carried out at 400-600℃ for 4-8 hours.

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