A method for preparing a propane dehydrogenation catalyst by using ACC wood preservative wastewater

Abstract

The application discloses a method for preparing a propane dehydrogenation catalyst by using ACC wood preservative wastewater, and comprises the following steps: after the ACC wood preservative wastewater is treated by precipitation, the upper clear liquid is filtered to remove impurities, then the clear liquid is concentrated to a saturated solution under normal pressure and at 75-85 DEG C, and the pH is adjusted to be less than or equal to 1, so that an impregnation solution is obtained; under stirring, a carrier is added into the impregnation solution for impregnation, the impregnated carrier is dried and calcined in air or nitrogen atmosphere, so that the propane dehydrogenation catalyst is obtained; the carrier is a composite porous material formed by an inorganic porous material and a pore-forming agent, or an inorganic porous material containing 3wt%-4wt% nickel. In the propane dehydrogenation catalyst prepared by the method, the chromium ions and the copper ions are both derived from the ACC wood preservative wastewater, the industrial wastewater is used for secondary utilization, and the preparation cost of the propane dehydrogenation catalyst is reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of environment and petrochemical industry, and particularly relates to a method for preparing a propane dehydrogenation catalyst by using ACC wood preservative wastewater. BACKGROUND

[0002] With the beginning of the North American shale oil and gas revolution, the overproduction of propane in the global chemical market has become an increasingly prominent trend. In order to consume the excess propane and convert it into propylene with higher industrial added value, the propane dehydrogenation industry (PDH) has received unprecedented attention.

[0003] Currently, there are four main propane dehydrogenation processes. The Oleflex process of UOP based on Pt-based catalyst and the Lummus process based on Cr-based catalyst are the most widely used processes. However, Pt-based catalysts have the characteristics of high purity requirements for raw materials, easy agglomeration and deactivation, and high price. Therefore, the toxic chromium-based catalyst has occupied a certain market space. For example, Chinese patent document CN112403458A discloses a dual-active-center propane dehydrogenation catalyst, which includes a carrier and an active ingredient supported on the carrier. The carrier uses a non-metallic carbon material, and the active ingredient uses an oxide of metallic chromium. Chinese patent document CN115501871A discloses a propane dehydrogenation catalyst, which includes: an alumina containing Group IVB elements as a carrier, Cr or its oxide as an active component, and Group IA and / or Group IIA elements or their oxides as an auxiliary component; wherein the catalyst passes the TPR test and appears an alloy peak of Group IVB elements and active component Cr elements in the range of 380-580℃.

[0004] It is reported that Cr in the main active site Cr2O3 in the chromium-based catalyst 6+ , Cr 5+ has a great influence on the health of aquatic plants and animals in natural water bodies and humans and animals. In order to alleviate the above problems, many research institutions at home and abroad have researched a variety of advanced adsorption materials to adsorb heavy metal ions such as high-valence chromium in water, so as to prevent irreversible damage to the natural water environment by heavy metal ions such as chromium and copper.

[0005] On the other hand, through preliminary market research, it is found that acidic copper chromate (ACC) wood preservative is one of the most widely used wood preservatives. Because it contains a large amount of chromium ions and copper ions in the preservative, the heavy metal ions need to be treated before being discharged. At present, the general treatment method of ACC wastewater needs to go through four steps: 1. Pretreatment: Pretreatment mainly includes solid-liquid separation, precipitation, filtration and other methods to separate suspended solids, sand and other impurities in the wastewater, and reduce the turbidity of the wastewater. For example, a sedimentation tank, filter and other equipment can be used for treatment. Neutralization reaction: The acidity and alkalinity of the wastewater may affect the subsequent treatment process, so neutralization treatment is needed. The pH value of the wastewater can be adjusted to a moderate range by adding acid or base. 2. Chemical precipitation: insoluble precipitates are generated by chemical reaction to precipitate ACC wood preservative and other harmful substances in the wastewater. Common chemical precipitants include aluminum hydroxide, iron hydroxide and the like. 3. Advanced treatment: After the wastewater is treated as above, there may still be some residual pollutants. Advanced treatment techniques such as ultrafiltration, nanofiltration, reverse osmosis and the like can be used to further improve the treatment effect of the wastewater. 4. Wastewater recycling or wastewater discharge: After the above treatment, the wastewater can reach a certain water quality standard and can be considered for recycling, such as for flushing, greening and the like to reduce water resource waste; or the treated wastewater can be discharged to the corresponding discharge port under the premise that the wastewater meets the relevant national discharge standards. However, the above treatment process is time-consuming and has a high economic cost. Therefore, the treatment of heavy metal ions in ACC preservative wastewater has been a problem to be solved.

[0006] It is of great significance to reuse ACC wastewater if the toxic hexavalent chromium in ACC wastewater can be used to prepare catalysts. SUMMARY

[0007] The purpose of the present application is to provide a method for preparing a propane dehydrogenation catalyst using ACC wood preservative wastewater, which can prepare a cheap Cr-based propane dehydrogenation catalyst while considering the treatment of hazardous chemicals and solving the problem of secondary utilization of ACC wood preservative wastewater containing heavy metal ions.

[0008] To achieve the above purpose, the present application provides a method for preparing a propane dehydrogenation catalyst using ACC wood preservative wastewater, comprising the following steps:

[0009] Pretreatment: at room temperature, the ACC wood preservative wastewater is treated by precipitation, and then the upper clear liquid is filtered to remove impurities, and then concentrated to a saturated solution at normal pressure and 75-85 DEG C, and the pH is adjusted to ≤1 to obtain an impregnation solution;

[0010] Impregnation: the carrier is added into the impregnation solution under stirring at 75-85℃ for impregnation, and the impregnated carrier is dried and calcined to obtain a propane dehydrogenation catalyst.

[0011] The carrier is a composite porous material formed by an inorganic porous material and a pore-forming agent, or an inorganic porous material containing 3wt%-4wt% nickel.

[0012] Optionally, in the method for preparing a propane dehydrogenation catalyst using ACC wood preservative wastewater provided by the application, the atmosphere for the calcination is air, hydrogen or nitrogen.

[0013] In the method for preparing a propane dehydrogenation catalyst using ACC wood preservative wastewater provided by the application, the inorganic porous material containing 3wt%-4wt% nickel is such that, based on 100% of the mass of the inorganic porous material containing nickel, the content of nickel is 3wt%-4wt%.

[0014] In the method for preparing a propane dehydrogenation catalyst using ACC wood preservative wastewater provided by the application, the purpose of adjusting the pH of the saturated solution to ≤1 is to ensure that the valence of the metal ions is maintained at a high valence Cr 6+ after subsequent calcination, so as to ensure the catalytic activity of the finally prepared catalyst.

[0015] In the method for preparing a propane dehydrogenation catalyst using ACC wood preservative wastewater provided by the application, after the ACC wood preservative wastewater is treated by precipitation, the upper clear liquid is filtered to remove impurities, floating matter and wood chips and the like in the ACC wood preservative wastewater, so as to ensure the safety and feasibility of the subsequent preparation of the dehydrogenation catalyst.

[0016] In the method for preparing a propane dehydrogenation catalyst using ACC wood preservative wastewater provided by the application, the saturated solution at normal pressure and 75-85℃ is limited to prevent the precipitation of metal salts and affect the subsequent impregnation effect. If the temperature is too low or too high, the content of metal salts in the saturated solution will be low, and the activity of the prepared catalyst will be poor.

[0017] Optionally, in the method for preparing a propane dehydrogenation catalyst using ACC wood preservative wastewater provided by the application, it is necessary to ensure that no solute is precipitated from the saturated ACC wood preservative wastewater during the impregnation process. The impregnation is recommended to be carried out in a rotary evaporating dish. Preferably, the impregnation time is 30-60min. By limiting the impregnation step to be carried out in a rotary evaporating dish, in combination with the limitation of the impregnation temperature and time, the precipitation of solute during the impregnation process can be prevented, and thus the effect of the impregnation is affected.

[0018] Optionally, in the method for preparing a propane dehydrogenation catalyst by using ACC wood preservative wastewater according to the present application, in the pretreatment step, the temperature of the concentration is 75-85°C.

[0019] Optionally, in the method for preparing a propane dehydrogenation catalyst by using ACC wood preservative wastewater according to the present application, the main heavy metal ions in the ACC wood preservative wastewater include chromium ions and copper ions, and the presence of copper ions can help the adsorption of chromium ions on the surface of the carrier. Chromium ions can also help the adsorption of copper ions on the surface of the carrier, and the two promote each other's adsorption.

[0020] Optionally, in the method for preparing a propane dehydrogenation catalyst by using ACC wood preservative wastewater according to the present application, the inorganic porous material is at least one selected from macroporous alumina, high-purity alumina, mesoporous silica, zinc oxide, zirconium oxide, boron nitride, and pseudo-boehmite.

[0021] Optionally, in the method for preparing a propane dehydrogenation catalyst by using ACC wood preservative wastewater according to the present application, the composite porous material is prepared by wet mixing the inorganic porous material with a pore-forming agent, and the mass ratio of the inorganic porous material to the pore-forming agent is preferably 2-5:1. The process parameters of the wet mixing method can be conventional in the industry, and are not specifically limited.

[0022] Optionally, in the method for preparing a propane dehydrogenation catalyst by using ACC wood preservative wastewater according to the present application, the pore-forming agent can be conventional in the industry, and for cost considerations, the pore-forming agent recommended by the present application is selected from sesbania gum and / or CMC (sodium carboxymethyl cellulose).

[0023] Optionally, in the method for preparing a propane dehydrogenation catalyst by using ACC wood preservative wastewater according to the present application, the inorganic porous material containing 3wt%-4wt% nickel is obtained by impregnating the inorganic porous material in a nickel nitrate solution, then aging, sintering at 700-750°C for 5-6h, and naturally cooling to room temperature. If the first impregnation does not meet the nickel loading requirement, the steps of impregnation, drying, and calcination can be repeated after sintering, and the impregnation is repeated multiple times until the required nickel loading requirement is met.

[0024] Optionally, in the method for preparing a propane dehydrogenation catalyst by using ACC wood preservative wastewater according to the present application, the aging procedure is first maintaining at 80-90°C for 3-4h, then immediately increasing the temperature to 120-140°C and maintaining for 4-12h.

[0025] The solvent of the nickel nitrate solution can be deionized water, and the concentration is not specifically limited, as long as the impregnation result is not affected. When the concentration is dilute, the loading requirement can be met by multiple impregnations. The concentration of the nickel nitrate recommended by the present application is 0.001mol / ml-0.01mol / ml.

[0026] Optionally, in the method for preparing the propane dehydrogenation catalyst by using the ACC wood preservative wastewater, the concentrated nitric acid is used to adjust the pH of the saturated solution.

[0027] Optionally, in the method for preparing the propane dehydrogenation catalyst by using the ACC wood preservative wastewater, the temperature of the calcination is 650-850°C, and the time is 7-10h.

[0028] Optionally, in the method for preparing the propane dehydrogenation catalyst by using the ACC wood preservative wastewater, the drying is vacuum drying, and the drying is first carried out at 75-85°C for 3-4h, and then carried out at 120-140°C for 12-14h.

[0029] The propane dehydrogenation catalyst prepared by the method for preparing the propane dehydrogenation catalyst by using the ACC wood preservative wastewater has a lateral pressure strength of 174-200N / cm.

[0030] Compared with the prior art, the method has the following advantages:

[0031] The propane dehydrogenation catalyst prepared by the method for preparing the propane dehydrogenation catalyst by using the ACC wood preservative wastewater has the following advantages: BRIEF DESCRIPTION OF DRAWINGS

[0032] Figure 1 The method for preparing the propane dehydrogenation catalyst by using the ACC wood preservative wastewater provided by the application is shown in the following schematic diagram:

[0033] In the schematic diagram, 1 is a filter, 2 is a heating furnace, 3 is an evaporation dish, 4 is a rotary evaporation dish, 5 is a rotary evaporator, and 6 is a shaped catalyst particle. DETAILED DESCRIPTION

[0034] The application will be described in detail below through examples. It is necessary to point out here that the following examples are only used to further illustrate the application, and cannot be understood as a limitation on the protection scope of the application. Those skilled in the art can make some non-essential improvements and adjustments to the application according to the above content of the application.

[0035] The specific experimental steps or conditions are not specified in the examples, and the operations or conditions can be carried out according to the conventional experimental steps described in the literature in the art. The reagents or instruments used are not specified by the manufacturer, and are all conventional reagent products that can be obtained by purchase.

[0036] The heavy metal ions such as chromium and copper contained in ACC wood preservative wastewater irreversibly destroy the natural water environment, and therefore, the heavy metal ions need to be treated before being discharged. The common ACC wastewater treatment method needs to go through four steps, which not only takes a long time, but also has a large economic cost. In order to reduce the pressure of ACC wood preservative wastewater on the environment and effectively utilize the heavy metal ions therein, the inventors creatively propose to use the heavy metal ions in ACC wood preservative wastewater as active ingredients in a propane dehydrogenation catalyst. However, due to the low concentration of heavy metal ions in ACC wood preservative wastewater and the presence of many other impurities, in order to ensure the safety and feasibility of using ACC wood preservative wastewater to prepare a dehydrogenation catalyst, the ACC wood preservative wastewater needs to be effectively pretreated.

[0037] The inventors have found that, by using neutralization pretreatment, although the impurities in ACC wood preservative wastewater can be effectively removed, a large amount of acid or base needs to be added, which increases the treatment cost; moreover, a large amount of sludge is generated, which further increases the treatment cost and environmental pressure; more seriously, due to the large fluctuation of the pH value of the wastewater, it is difficult to achieve a stable neutralization effect, which leads to unstable acid-base adjustment, directly affecting the preparation of the subsequent catalyst and the catalytic effect. By using adsorption pretreatment, the price of the adsorbent (such as activated carbon) is relatively high, and the adsorbent is easy to saturate and needs to be replaced regularly. The used adsorbent contains a large amount of pollutants and needs to be safely disposed to prevent secondary pollution, and the treatment process is complex and has a high cost. The inventors have found that, by using precipitation, the ACC wastewater including the dust coated with preservative and wood chips and other substances can be removed, then the supernatant is filtered, and after being concentrated into a saturated solution at a specific temperature, the pH value is adjusted to be ≤1. The whole pretreatment process does not introduce any new metal or non-metal atoms, and effectively increases the concentration of heavy metal ions in the ACC wastewater, which provides a certain guarantee for the activity of the finally prepared catalyst. Moreover, by adjusting the pH value after precipitation and concentration, the stability of the acid-base adjustment is increased, which can effectively prevent the existence of the metal valence state on the surface of the carrier after impregnation due to the increase of the pH value, thereby affecting the activity of the catalyst.

[0038] The dehydrogenation catalyst has good dispersity, activity and stability, so as to ensure the dehydrogenation reaction effect. In order to ensure that the prepared dehydrogenation catalyst has good dispersity, activity and stability, a suitable carrier and method need to be used for preparation. The content of copper contained in the catalyst prepared from ACC wood preservative wastewater is relatively high, which is caused by the d-electron saturation of copper. The high content of copper makes the dehydrogenation activity of the catalyst not very strong, but the high content of copper can play a role in dispersing the main dehydrogenation active center Cr. The oxide cluster of chromium is the main active site of the catalyst. When the size of the active site increases, the selectivity of the active site and the side reactions such as carbon deposition and cracking will increase. Therefore, the element with weak dehydrogenation activity needs to be distributed on the surface of the carrier, so as to improve the stability of the catalyst, reduce the generation of carbon deposition and improve the selectivity of the catalyst to propylene. The single inorganic carrier has poor dispersity of chromium metal, and has no electronic regulation effect on the main active site.

[0039] In order to make up for the shortcomings of conventional inorganic porous materials as the carrier of the dehydrogenation catalyst, the inventors have further found that: 1) the above shortcomings can be made up by loading a certain amount of Ni element on the surface of the inorganic porous material, because: Ni forms a spinel structure in the inorganic porous material, in which the nickel element presents a four-coordinated positive divalent structure, has a certain dehydrogenation activity, and assists the main active site to complete the dehydrogenation process. Due to the existence of the spinel structure, the carbon deposition of the catalyst is reduced, the stability and hardness thereof are improved, and thus the robustness of the industrial dehydrogenation catalyst in harsh environment is ensured. From the electronic effect, the introduction of nickel metal is equivalent to doping of an additive, which plays a role in supplying electrons to chromium. The surface of the chromium oxide is rich in electrons, which is beneficial to the desorption of propylene, so as to reduce the carbon deposition and improve the selectivity of propylene. 2) the above shortcomings can also be made up by using the composite carrier formed by the pore-forming agent and the inorganic porous material, because propane dehydrogenation is a gas-solid phase catalysis in heterogeneous catalysis. The addition of the pore-forming agent can significantly increase the surface area of the inorganic porous material with small specific surface area, so as to form developed pores and improve the anti-carbon deposition capacity and reaction stability of the carrier. Meanwhile, the regeneration capacity of the catalyst is also significantly improved.

[0040] In summary, under the premise that the dehydrogenation catalyst prepared from the heavy metal ions in the ACC wood preservative wastewater has good dispersity, activity and stability, the ACC wood preservative wastewater needs to be effectively pretreated, and then a suitable carrier and method are selected for effective loading. Therefore, there are many and complex factors affecting the preparation of the dehydrogenation catalyst from the ACC wastewater. Through overall and in-depth research, the inventors finally determine that the pretreatment method including sequential precipitation, filtration and concentration into a saturated solution at 75-85℃, and then adjusting pH≤1, combined with a specific carrier and impregnation loading method, can ensure the application effect of the prepared catalyst.

[0041] In order to further illustrate the technical scheme of the present application, the following specific examples are used to embody the present application. It should be noted that the following specific examples do not constitute a limitation on the scope of protection of the present application.

[0042] For the convenience of comparison, the raw materials involved in the preparation of the catalyst in the following specific examples are all of analytical purity (AR), and the nickel nitrate is purchased from Aladdin Reagent Company; the rotary evaporation equipment required for the experiment is produced by Ruiyi Instrument Company; the tamarind seed gum is purchased from Beijing Mining Research Institute; and the pseudoboehmite is purchased from Alumina ShanDong New Material Co., Ltd. and Alumina Shanxi Co., Ltd.

[0043] Example 1

[0044] The present example provides a method for preparing a propane dehydrogenation catalyst using ACC wood preservative wastewater. The partial pretreatment and impregnation process is shown in Figure 1 and specifically includes the following steps:

[0045] Pretreatment: At room temperature, the ACC wood preservative wastewater is allowed to stand and precipitate, and then the supernatant is filtered using a filter 1. The obtained filtrate is placed in an evaporating dish 3, and is concentrated to a saturated solution at 80°C under normal pressure using a heating furnace 2 heated to 75-85°C. Then, the pH value of the saturated solution is tested using an acidic pH test paper, and concentrated nitric acid is slowly added to adjust the pH of the saturated solution to ≤1, thereby obtaining an impregnation solution.

[0046] Carrier: The pseudoboehmite of Alumina ShanDong New Material Co., Ltd., the tamarind seed gum of Beijing Mining Research Institute, and the macroporous alumina of Alumina ShanDong New Material Co., Ltd. are dry-mixed in a mass ratio of 3:1:0.2. After being uniformly mixed, deionized water is added and stirred uniformly to form a viscous state. Then, the mixture is put into a kneader and fully kneaded at a rotation speed of 900 r / min. After that, the mixture is extruded into strips in an extruder with a pore diameter of 2 mm. The formed sample is dried and calcined, thereby obtaining a catalyst carrier. The drying program is: first maintained at 60°C for 4 hours, and then maintained at 120°C for 4 hours. The calcination program is: heated from room temperature to 750°C at a rate of 5°C / min, and maintained for 8 hours. Then, it is naturally cooled to room temperature.

[0047] Impregnation: The above catalyst carrier is placed in a rotary evaporating dish 4 and preheated to 70-80°C. Then, the above impregnation solution is added, and under the stirring action of a rotary evaporator 5, the catalyst carrier is impregnated at an equal volume for 30 min at 75-85°C. The obtained shaped catalyst particles 6 are placed in a surface dish, and then put into a vacuum oven for drying: first maintained at 80°C for 3 hours, and then immediately heated to 120°C and maintained for 12 hours. Then, the dried sample is immediately placed in a muffle furnace for calcination: heated to about 800°C in an air atmosphere and maintained for 7 hours, and then naturally cooled to room temperature. Thus, a propane dehydrogenation catalyst is obtained.

[0048] Comparative Example 1-1

[0049] Comparative Example 1-1 is basically the same as Example 1, except that the support used is loaded with nickel. The preparation process of the support used in this comparative example is as follows:

[0050] The preparation method of the intermediate support is the same as that of the support in Example 1.

[0051] The intermediate support is placed in a 0.006 mol / ml aqueous solution of nickel nitrate for impregnation, then dried at 80°C for 3h, then at 120°C for 5h, and finally sintered at 700°C for 5h. The content of nickel is detected to be 2wt%, and a catalyst support containing 2wt% nickel is obtained.

[0052] The nickel loaded in this comparative example is used as an auxiliary agent for a chromium / copper-based catalyst to improve the initial catalytic activity and stability of the catalyst.

[0053] Comparative Example 1-2

[0054] Comparative Example 1-2 is basically the same as Example 1, except that the support used is loaded with nickel. The preparation process of the support used in this comparative example is as follows:

[0055] The preparation method of the intermediate support is the same as that of the support in Example 1.

[0056] The intermediate support is placed in a 0.01 mol / ml aqueous solution of nickel nitrate for impregnation, then dried at 80°C for 3h, then at 120°C for 8h, and finally sintered at 700°C for 5h. The content of nickel is detected to be 3.5wt%, and a catalyst support containing 3.5wt% nickel is obtained.

[0057] The nickel loaded in this comparative example is also used as an auxiliary agent for a chromium / copper-based catalyst to improve the initial catalytic activity and stability of the catalyst.

[0058] Example 2

[0059] The present example provides a method for preparing a propane dehydrogenation catalyst using ACC wood preservative wastewater, which specifically comprises the following steps:

[0060] Pretreatment: The ACC wood preservative wastewater is allowed to stand and precipitate at room temperature, and then the supernatant is filtered to obtain a filtrate. The filtrate is concentrated at normal pressure and 75-85°C to a saturated solution at 80°C, and then the pH value of the saturated solution is tested using an acidic pH test paper, and concentrated nitric acid is slowly added to adjust the pH of the saturated solution to ≤1 to obtain an impregnation solution.

[0061] Carrier: high-purity mesoporous silica is put into a 0.008 mol / ml nickel nitrate aqueous solution for impregnation, then is first maintained at 80°C for 3 h, then is maintained at 120°C for 8 h for maturation, and finally is sintered at 700°C for 5 h, and the content of nickel therein is detected to be 3 wt%, thereby obtaining the high-purity mesoporous silica carrier containing 3 wt% of nickel.

[0062] Impregnation: the above catalyst carrier is put into the above impregnation solution in a rotary evaporating dish for equal-volume impregnation at 75-85°C for 60 min, and the impregnated carrier is placed in a surface dish and is dried in a vacuum oven: first maintained at 80°C for 3 h, then immediately increased to 120°C and maintained for 12 h; then the dried sample is immediately placed in a muffle furnace for calcination: increased to about 800°C in an air atmosphere and maintained for 7 h, and then naturally decreased to room temperature, thereby obtaining the propane dehydrogenation catalyst.

[0063] Comparative Example 2

[0064] This comparative example is basically the same as Example 2, except that the content of nickel supported on the high-purity mesoporous silica carrier used is different, and in this comparative example, the content of nickel supported on the high-purity mesoporous silica carrier is 2.5 wt%, and the specific operation is as follows:

[0065] The high-purity mesoporous silica is put into a 0.004 mol / ml nickel nitrate aqueous solution for impregnation, then is first maintained at 80°C for 3 h, then is maintained at 120°C for 12 h for maturation, and finally is sintered at 700°C for 5 h, and the content of nickel therein is detected to be 2.5 wt%, thereby obtaining the high-purity mesoporous silica carrier containing 2.5 wt% of nickel.

[0066] Example 3

[0067] This example provides a method for preparing a propane dehydrogenation catalyst by using ACC wood preservative wastewater, and specifically includes the following steps:

[0068] Pretreatment: the ACC wood preservative wastewater is allowed to stand and precipitate at room temperature, then the upper clear liquid is taken and filtered, the obtained filtrate is concentrated at normal pressure and 75-85°C to a saturated solution at 80°C, then the pH value of the saturated solution is tested using an acidic pH test paper, and concentrated nitric acid is slowly added to adjust the pH of the saturated solution to ≤1, thereby obtaining the impregnation solution.

[0069] Carrier: zirconia is put into a 0.08 mol / ml nickel nitrate aqueous solution for impregnation, then is first maintained at 80°C for 3 h, then is maintained at 120°C for 12 h for maturation, and finally is sintered at 700°C for 5 h, and the content of nickel therein is detected to be 3 wt%, thereby obtaining the zirconia carrier containing 3 wt% of nickel.

[0070] Impregnation: The above catalyst carrier was put into the above impregnation solution in a rotary evaporating dish and impregnated at an equal volume for 40 min at 75-85°C. The impregnated carrier was placed in a surface dish and dried in a vacuum oven: first at 80°C for 3 hours, then immediately raised to 120°C and kept for 12 hours. The dried sample was then immediately placed in a muffle furnace for calcination: raised to 800°C in a nitrogen atmosphere and kept for 7 hours, and then naturally reduced to room temperature to obtain a propane dehydrogenation catalyst.

[0071] Comparative Example 3

[0072] Comparative Example 3 is basically the same as Example 3, except that the atmosphere during calcination in the impregnation step is different. In the comparative example, the dried sample was immediately placed in a muffle furnace for calcination: raised to about 800°C in an argon atmosphere and kept for 7 hours, and then naturally reduced to room temperature to obtain a propane dehydrogenation catalyst.

[0073] Example 4

[0074] The present example provides a method for preparing a propane dehydrogenation catalyst using ACC wood preservative wastewater, which specifically comprises the following steps:

[0075] Pre-treatment: The ACC wood preservative wastewater was allowed to stand and precipitate at room temperature, and then the supernatant was filtered to obtain a filtrate. The filtrate was concentrated at normal pressure and 75-85°C to a saturated solution at 80°C, and then the pH value of the saturated solution was tested using an acid pH test paper, and concentrated nitric acid was slowly added to adjust the pH of the saturated solution to ≤1 to obtain an impregnation solution.

[0076] Carrier: The pseudoboehmite of Zibo Hengyi Co., Ltd., the canavalia gladiate of Beijing Mining Research Institute, and the macroporous alumina of Zibo Hengyi Co., Ltd. were dry-mixed in a mass ratio of 3:1:0.2. After being mixed uniformly, deionized water was added and stirred uniformly to form a viscous state, and then put into a kneader for full kneading at a speed of 900 r / min. After that, the sample was extruded into a strip in an extruder with a pore diameter of 2 mm. The formed sample was dried and calcined to obtain a catalyst carrier. The drying program was: first at 60°C for 4 hours, and then at 120°C for 4 hours. The calcination program was: raised from room temperature to 750°C at a rate of 5°C / min, and kept for 8 hours, and then naturally reduced to room temperature.

[0077] Impregnation: Put the catalyst carrier into the impregnation solution above in a rotary evaporating dish and impregnate at 75-85°C for 55 min. Put the impregnated carrier in a surface dish and place it in a vacuum oven for drying: first maintain at 80°C for 3 hours, then immediately raise the temperature to 120°C and maintain for 12 hours. Then immediately place the dried sample in a muffle furnace for calcination: raise the temperature to about 800°C in an air atmosphere and maintain for 7 hours, and then naturally reduce to room temperature. Thus, a propane dehydrogenation catalyst is obtained.

[0078] Example 5

[0079] This example provides a method for preparing a propane dehydrogenation catalyst using ACC wood preservative wastewater, which specifically comprises the following steps:

[0080] Pre-treatment: At room temperature, the ACC wood preservative wastewater is allowed to stand and precipitate, and then the supernatant is filtered. The obtained filtrate is concentrated at 75-85°C under normal pressure to a saturated solution at 80°C. Then, the pH value of the saturated solution is tested using an acidic pH test paper, and concentrated nitric acid is slowly added to adjust the pH of the saturated solution to ≤1. Thus, an impregnation solution is obtained.

[0081] Carrier: The pseudoboehmite and the pore-forming agent CMC are dry-mixed according to a mass ratio of 2.5:1. After uniform mixing, deionized water is added and stirred uniformly to form a viscous state. Then, the mixture is placed in a kneader and fully kneaded at a rotation speed of 900 r / min. After that, the mixture is extruded into strips in an extruder with a pore diameter of 2 mm. The formed sample is dried and calcined, and thus a catalyst carrier is obtained. The drying procedure is: first maintain at 60°C for 4 hours, and then maintain at 120°C for 4 hours. The calcination procedure is: raise the temperature from room temperature to 750°C at a rate of 5°C / min, and maintain for 8 hours, and then naturally reduce to room temperature.

[0082] Impregnation: Put the catalyst carrier into the impregnation solution above in a rotary evaporating dish and impregnate at 75-85°C for 35 min. Put the impregnated carrier in a surface dish and place it in a vacuum oven for drying: first maintain at 80°C for 3 hours, then immediately raise the temperature to 120°C and maintain for 12 hours. Then immediately place the dried sample in a muffle furnace for calcination: raise the temperature to about 800°C in an air atmosphere and maintain for 7 hours, and then naturally reduce to room temperature. Thus, a propane dehydrogenation catalyst is obtained.

[0083] Example 6

[0084] This example provides a method for preparing a propane dehydrogenation catalyst using ACC wood preservative wastewater, which specifically comprises the following steps:

[0085] Pre-treatment: The ACC wood preservative wastewater was allowed to stand and precipitate at room temperature, and then the supernatant was filtered to obtain a filtrate. The filtrate was concentrated at normal pressure and 75-85°C to a saturated solution at 80°C, and then the pH value of the saturated solution was tested using an acidic pH test paper, and concentrated nitric acid was slowly added to adjust the pH of the saturated solution to be ≤1 to obtain an impregnation solution.

[0086] Support: The high-purity mesoporous silica was immersed in a 0.01 mol / ml nickel nitrate aqueous solution, and then was aged at 90°C for 3 h, at 130°C for 6 h, and finally sintered at 750°C for 5.5 h. The content of nickel in the high-purity mesoporous silica support containing 3.5 wt% nickel was 3.5 wt%.

[0087] Impregnation: The catalyst support was placed in the impregnation solution in a rotary evaporating dish and impregnated at 75-85°C for 60 min. The impregnated support was placed in a surface dish and dried in a vacuum oven: first at 80°C for 3 h, then immediately heated to 120°C and kept for 12 h. The dried sample was immediately placed in a muffle furnace for calcination: heated to about 800°C in an air atmosphere and kept for 7 h, and then naturally cooled to room temperature to obtain a propane dehydrogenation catalyst.

[0088] Example 7

[0089] The present embodiment provides a method for preparing a propane dehydrogenation catalyst using ACC wood preservative wastewater, which specifically comprises the following steps:

[0090] Pre-treatment: The ACC wood preservative wastewater was allowed to stand and precipitate at room temperature, and then the supernatant was filtered to obtain a filtrate. The filtrate was concentrated at normal pressure and 75-85°C to a saturated solution at 80°C, and then the pH value of the saturated solution was tested using an acidic pH test paper, and concentrated nitric acid was slowly added to adjust the pH of the saturated solution to be ≤1 to obtain an impregnation solution.

[0091] Support: The high-purity mesoporous silica was immersed in a 0.01 mol / ml nickel nitrate aqueous solution, and then was aged at 90°C for 3 h, at 130°C for 6 h, and finally sintered at 750°C for 5.5 h. The content of nickel in the high-purity mesoporous silica support containing 3.5 wt% nickel was 3.5 wt%.

[0092] Impregnation: The above catalyst carrier was put into the above impregnation solution in a rotary evaporating dish and impregnated for 40 min at 75-85℃ in equal volume, and the impregnated carrier was placed in a surface dish and dried in a vacuum oven: first at 80℃ for 3 hours, then immediately heated to 120℃ and kept for 12 hours; then the dried sample was immediately placed in a muffle furnace for calcination: heated to about 700℃ in a hydrogen atmosphere and kept for 7 hours, and then naturally reduced to room temperature, thereby obtaining a propane dehydrogenation catalyst.

[0093] Experimental Example

[0094] The catalysts prepared in each example and comparative example were respectively subjected to tabletting and sieving treatment, and particles of 20-40 mesh were sieved out and respectively filled in a 10 mL fixed bed stainless steel fixed bed reactor, and the reaction was carried out under normal pressure at a propane volume space velocity of 2h-1 and a reaction temperature of 600℃ to prepare propylene by propane dehydrogenation, and the specific 1-hour sampling catalyst evaluation results are shown in the following table. -1

[0095] The catalysts prepared in each example and comparative example were respectively subjected to tabletting and sieving treatment, and particles of 20-40 mesh were sieved out and respectively filled in a 10 mL fixed bed stainless steel fixed bed reactor, and the reaction was carried out under normal pressure at a propane volume space velocity of 2h-1 and a reaction temperature of 600℃ to prepare propylene by propane dehydrogenation, and the specific 1-hour sampling catalyst evaluation results are shown in the following table.

[0096] Table 1

[0097]

[0098]

[0099] From the data in the above table, it can be seen that the conversion rate, selectivity, yield and mechanical strength of the propane dehydrogenation catalyst prepared by the method for preparing a propane dehydrogenation catalyst using ACC wood preservative wastewater provided by the application are basically close to the catalytic activity of the commercially available Cr dehydrogenation catalyst, and the cost is low, and the heavy metal ions in the ACC wood preservative wastewater are secondarily utilized.

[0100] Of course, the present application also has other various embodiments, and those skilled in the art can make various corresponding changes and modifications according to the present application without departing from the spirit and essence of the present application, but these corresponding changes and modifications should all belong to the protection scope of the claims of the present application.​

Claims

1. A method for preparing a propane dehydrogenation catalyst using ACC wood preservative wastewater, characterized by, The method comprises the following steps: Pre-treatment: after the ACC wood preservative wastewater is treated by precipitation, the upper clear liquid is filtered to remove impurities, then the clear liquid is concentrated to a saturated solution at normal pressure and 75-85 DEG C, and the pH is adjusted to be less than or equal to 1, thereby obtaining an impregnation solution; Impregnation: under stirring and at 75-85 DEG C, a carrier is added into the impregnation solution for impregnation, and the impregnated carrier is dried and calcined, thereby obtaining a propane dehydrogenation catalyst; The carrier is a composite porous material formed by an inorganic porous material and a pore-forming agent, or an inorganic porous material containing 3wt%-4wt% nickel.

2. The method of claim 1, wherein, In the impregnation step, the atmosphere for calcination is air, hydrogen or nitrogen.

3. The method of claim 1, wherein, The impregnation is performed in a rotary evaporator.

4. The method of claim 1, wherein, The inorganic porous material is selected from at least one of macroporous alumina, high-purity alumina, mesoporous silica, zinc oxide, zirconium oxide, boron nitride and pseudo-boehmite.

5. The method of claim 1, wherein, The composite porous material is prepared by wet mixing the inorganic porous material and the pore-forming agent.

6. The method of claim 1, wherein, The inorganic porous material containing 3wt%-4wt% nickel is prepared by impregnating an inorganic porous material in a nickel nitrate solution, then aging and sintering at 700-750 DEG C for 5-6h.

7. The method of claim 6, wherein, The aging procedure comprises: first maintaining at 80-90 DEG C for 3-4h, and then maintaining at 120-140 DEG C for 4-12h; and / or The concentration of the nickel nitrate is 0.001mol / ml-0.01mol / ml.

8. The method of claim 1, wherein, In the pre-treatment step, concentrated nitric acid is used to adjust the pH of the saturated solution.

9. The method of claim 1, wherein, The drying is vacuum drying, first at 75-85 DEG C for 3-4h, and then at 120-140 DEG C for 12-14h.

10. The method of claim 1, wherein, The calcination temperature is 650-850 DEG C, and the time is 7-10h.

11. The method of claim 3, wherein, The impregnation time is 30-60min.

12. The method of claim 5, wherein, The mass ratio of the inorganic porous material to the pore-forming agent is 2-5:1.

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