Preparation method of molecular oxidation catalyst

Abstract

The invention discloses a preparation method of a molecular oxidation catalyst. The preparation method comprises the following steps: mixing: mixing formic acid metal salt, a binder, an auxiliary agent and a flexibilizer; a mixed solid material is obtained; stirring: adding deionized water into the mixed solid material and stirring to obtain a wet material; granulation: molding the wet material by using granulation equipment to obtain a molded wet material; drying: drying the formed wet material in a high-temperature furnace; sintering: continuously heating and sintering the dried forming material to obtain the molecular oxidation catalyst. The mass ratio of the effective components of the formic acid metal salt is higher, and less metal salt is used for achieving the same catalytic effect. According to the preparation method provided by the invention, the sintering generated gas is free of nitrogen oxide and is only carbon dioxide, so that the method is environment-friendly. The preparation method is lower in sintering temperature, energy-saving and consumption-reducing.

Description

Technical Field

[0001] The invention belongs to the technical field of new materials, and more specifically, relates to a method for preparing a molecular oxidation catalyst. Background Art

[0002] Molecular catalytic oxidation technology is an efficient wastewater deep treatment technology and has been a hot application in the field of wastewater treatment in recent years. Compared with ozone as a single oxidant, the hydroxyl radicals formed by ozone under the action of a catalyst have a higher reaction rate with organic matter and stronger oxidizing properties, and can oxidize almost all organic matter. The catalyst can catalyze ozone to directly oxidize organic matter in water into CO2 and H2O, or oxidize and decompose large molecular organic matter into small molecules, making it easier to degrade.

[0003] The metal active substances prepared by traditional molecular oxidation catalysts are usually metal nitrate salts. The content of effective substances in the preparation process is low, the calcination temperature is high, and gases such as nitrogen oxides are emitted, polluting the atmospheric environment. At the same time, the catalytic effect of the prepared molecular oxidation catalyst is relatively poor and cannot meet the requirements of deep wastewater treatment. Summary of the invention

[0004] In view of the current situation, the present invention provides a method of using metal formate salts to replace metal nitrate salts in traditional processes, so as to prepare a molecular oxidation catalyst in a more efficient, environmentally friendly and energy-saving manner; the metal formate salts have a higher effective ingredient content; the sintering gas is only carbon dioxide, which is environmentally friendly; the sintering temperature is lower, which saves energy and reduces consumption.

[0005] An object of the present invention is to solve at least the above problems and / or disadvantages and to provide at least the advantages which will be described hereinafter.

[0006] In order to achieve these purposes and other advantages according to the present invention, a method for preparing a molecular oxidation catalyst is provided, comprising the following steps:

[0007] Step 1: Mixing: Mixing metal formate, pseudo-boehmite, auxiliary agent and toughening agent to obtain a mixed solid material;

[0008] Step 2: stirring: adding the mixed solid material into deionized water and stirring to obtain a wet material;

[0009] Step 3: Forming: forming the wet material by granulating equipment to obtain formed wet material;

[0010] Step 4: Drying: Place the wet molded material in a high temperature furnace to dry;

[0011] Step 5: Sintering: Continue to heat up and sinter the dried molding material to obtain a molecular oxidation catalyst.

[0012] Preferably, in step 1, the metal formate salt is one or more of copper formate, manganese formate, iron formate, zinc formate, chromium formate and molybdenum formate.

[0013] Preferably, in the step 1, the pseudo-boehmite is pretreated before use, and the pretreatment method is: taking a formate metal salt solution with a concentration of 0.5 to 1 g / L to impregnate the pseudo-boehmite for 1 to 3 hours, filtering the impregnated material, and drying it at 100° C. for 2 to 3 hours to pretreat the pseudo-boehmite; the mass volume ratio of the pseudo-boehmite to the formate metal salt solution is 1 g:10 to 15 mL.

[0014] Preferably, the pseudo-boehmite is pretreated before use, and the pretreatment method is: taking a metal formate salt and adding it into a supercritical carbon dioxide reactor, adding the pseudo-boehmite at the same time, and then introducing carbon dioxide gas, raising the temperature and pressure to a supercritical state, starting stirring to fully mix and immerse for 1 hour, and collecting the material after cooling and reducing the pressure, that is, pretreating the pseudo-boehmite; the mass ratio of the pseudo-boehmite to the metal formate salt is 0.5 to 1:100; the heating temperature is 40 to 50°C, and the pressure is 25 to 35MPa.

[0015] Preferably, in step 1, the auxiliary agent is one or more of sesbania powder, starch, chitosan, and polyvinyl pyrrolidone.

[0016] Preferably, in step 1, the toughening agent is one or more of nano-attapulgite, nano-kaolin, nano-silicon dioxide, and nano-titanium dioxide.

[0017] Preferably, in step 1, the mass ratio of the binder, auxiliary agent, toughening agent and metal formate is (50-90):(5-30):(2-8):(1-8):(1-10); and the mixing time is 0.5-5h.

[0018] Preferably, in step 2, the water content in the wet material is 15-60wt% and the stirring time is 0.5-4h.

[0019] Preferably, in the step three, the wet material is formed into a cylinder with a diameter of 1 mm to 8 mm and a length of 10 mm to 60 mm using a granulating device.

[0020] Preferably, in step 4, the drying temperature is 40-250° C. and the drying time is 1-8 hours.

[0021] Preferably, in step five, the sintering temperature is 300-550° C. and the sintering time is 1-12 hours.

[0022] The present invention has at least the following beneficial effects:

[0023] (1) The preparation method provided by the present invention generates sintering gas without nitrogen oxides and only carbon dioxide, which is environmentally friendly.

[0024] (2) Compared with the prior art using metal nitrate, the preparation method of the present invention has the advantages of lower sintering temperature and energy saving.

[0025] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention.

[0026] Other advantages, objectives and features of the present invention will be embodied in part through the following description, and in part will be understood by those skilled in the art through study and practice of the present invention. DETAILED DESCRIPTION

[0027] The present invention is further described in detail below in conjunction with embodiments so that those skilled in the art can implement the invention with reference to the description.

[0028] It should be understood that terms such as “having”, “including” and “comprising” used herein do not specify the existence or addition of one or more other elements or combinations thereof.

[0029] Embodiment 1:

[0030] A method for preparing a molecular oxidation catalyst comprises the following steps:

[0031] Step 1: Evenly mix 90 g of pseudo-boehmite, 3 g of sesbania powder, 2 g of nano-silicon dioxide, and 5 g of iron formate in a mixer for 30 min to obtain a mixed solid material;

[0032] Step 2: Add deionized water to the mixed solid material and stir for 1 hour to obtain a wet material, wherein the water content in the wet material is 30wt%;

[0033] Step 3: Put the wet material into an extruder to prepare a cylindrical catalyst with a diameter of 3 mm and a length of 5-15 mm;

[0034] Step 4: Dry the cylindrical catalyst at 50°C for 1h;

[0035] Step 5: calcine the dried cylindrical catalyst at 300° C. for 4 h to obtain a molecular oxidation catalyst.

[0036] Embodiment 2:

[0037] A method for preparing a molecular oxidation catalyst comprises the following steps:

[0038] Step 1: Evenly mix 90 g of pseudo-boehmite, 3 g of starch, 2 g of nano-silicon dioxide, and 5 g of copper formate in a mixer for 30 min to obtain a mixed solid material;

[0039] Step 2: Add deionized water to the mixed solid material and stir for 1 hour to obtain a wet material, wherein the water content in the wet material is 40wt%;

[0040] Step 3: Put the wet material into an extruder to prepare a cylindrical catalyst with a diameter of 3 mm and a length of 5-15 mm;

[0041] Step 4: Dry the cylindrical catalyst at 100°C for 1 hour;

[0042] Step 5: calcine the dried cylindrical catalyst at 400° C. for 4 h to obtain a molecular oxidation catalyst.

[0043] Embodiment 3:

[0044] A method for preparing a molecular oxidation catalyst comprises the following steps:

[0045] Step 1: Evenly mix 90 g of pseudo-boehmite, 3 g of starch, 2 g of nano-silicon dioxide, and 5 g of chromium formate in a mixer for 30 min to obtain a mixed solid material;

[0046] Step 2: Add deionized water to the mixed solid material and stir for 1 hour to obtain a wet material, wherein the water content in the wet material is 50wt%;

[0047] Step 3: Put the wet material into an extruder to prepare a cylindrical catalyst with a diameter of 3 mm and a length of 5-15 mm;

[0048] Step 4: Dry the cylindrical catalyst at 150°C for 0.5h;

[0049] Step 5: calcine the dried cylindrical catalyst at 450° C. for 3 h to obtain a molecular oxidation catalyst.

[0050] Embodiment 4:

[0051] A method for preparing a molecular oxidation catalyst comprises the following steps:

[0052] Step 1, pre-treating the pseudo-boehmite before use, wherein the pre-treatment method is as follows: taking 1000 mL of 1 g / L iron formate solution to impregnate 100 g of pseudo-boehmite for 1 hour, filtering the impregnated material, and drying it at 100° C. for 2 hours to pre-treat the pseudo-boehmite; by first impregnating the active component of the metal formate salt onto the pseudo-boehmite, the activity of the catalyst can be further improved;

[0053] 90 g of pretreated pseudo-boehmite, 3 g of sesbania powder, 2 g of nano-silicon dioxide, and 5 g of ferric formate were uniformly mixed in a mixer for 30 min to obtain a mixed solid material;

[0054] Step 2: Add deionized water to the mixed solid material and stir for 1 hour to obtain a wet material, wherein the water content in the wet material is 30wt%;

[0055] Step 3: Put the wet material into an extruder to prepare a cylindrical catalyst with a diameter of 3 mm and a length of 5-15 mm;

[0056] Step 4: Dry the cylindrical catalyst at 50°C for 1h;

[0057] Step 5: calcine the dried cylindrical catalyst at 300° C. for 4 h to obtain a molecular oxidation catalyst.

[0058] Embodiment 5:

[0059] A method for preparing a molecular oxidation catalyst comprises the following steps:

[0060] Step 1, pre-treating the pseudo-boehmite before use, the pre-treatment method is: taking 1g of iron formate and adding it into a supercritical carbon dioxide reactor, adding 100g of pseudo-boehmite at the same time, then introducing carbon dioxide gas, raising the temperature (45°C) and the pressure (30MPa) to a supercritical state, stirring and fully mixing and impregnating for 1 hour, cooling and reducing the pressure, and collecting the material, that is, pre-treating the pseudo-boehmite; by first impregnating the active component of the metal formate salt onto the pseudo-boehmite, the activity of the catalyst can be further improved; and the impregnation is performed by supercritical carbon dioxide, and the low surface tension and low viscosity of supercritical carbon dioxide make the impregnation effect better, and the distribution of the active component of the metal formate salt in the pseudo-boehmite is more uniform, so that it can further improve the activity of the catalyst;

[0061] 90 g of pretreated pseudo-boehmite, 3 g of sesbania powder, 2 g of nano-silicon dioxide, and 5 g of ferric formate were uniformly mixed in a mixer for 30 min to obtain a mixed solid material;

[0062] Step 2: Add deionized water to the mixed solid material and stir for 1 hour to obtain a wet material, wherein the water content in the wet material is 30wt%;

[0063] Step 3: Put the wet material into an extruder to prepare a cylindrical catalyst with a diameter of 3 mm and a length of 5-15 mm;

[0064] Step 4: Dry the cylindrical catalyst at 50°C for 1h;

[0065] Step 5: calcine the dried cylindrical catalyst at 300° C. for 4 h to obtain a molecular oxidation catalyst.

[0066] Embodiment 6:

[0067] A method for preparing a molecular oxidation catalyst comprises the following steps:

[0068] Step 1, pre-treating the pseudo-boehmite before use, wherein the pre-treatment method is as follows: taking 1000 mL of a 0.8 g / L copper formate solution to impregnate 100 g of the pseudo-boehmite for 1 hour, filtering the impregnated material, and drying at 100° C. for 2 hours to pre-treat the pseudo-boehmite;

[0069] 90 g of pretreated pseudo-boehmite, 3 g of starch, 2 g of nano-silicon dioxide, and 5 g of copper formate were uniformly mixed in a mixer for 30 min to obtain a mixed solid material;

[0070] Step 2: Add deionized water to the mixed solid material and stir for 1 hour to obtain a wet material, wherein the water content in the wet material is 40wt%;

[0071] Step 3: Put the wet material into an extruder to prepare a cylindrical catalyst with a diameter of 3 mm and a length of 5-15 mm;

[0072] Step 4: Dry the cylindrical catalyst at 100°C for 1 hour;

[0073] Step 5: calcine the dried cylindrical catalyst at 400° C. for 4 h to obtain a molecular oxidation catalyst.

[0074] Embodiment 7:

[0075] A method for preparing a molecular oxidation catalyst comprises the following steps:

[0076] Step 1, pre-treating the pseudo-boehmite before use, the pre-treatment method is: taking 0.8g of copper formate and adding it into a supercritical carbon dioxide reactor, adding 100g of pseudo-boehmite at the same time, and then introducing carbon dioxide gas, raising the temperature (45°C) and the pressure (30MPa) to a supercritical state, stirring and fully mixing and impregnating for 1 hour, cooling and reducing the pressure and collecting the material, that is, pre-treating the pseudo-boehmite;

[0077] 90 g of pretreated pseudo-boehmite, 3 g of starch, 2 g of nano-silicon dioxide, and 5 g of copper formate were uniformly mixed in a mixer for 30 min to obtain a mixed solid material;

[0078] Step 2: Add deionized water to the mixed solid material and stir for 1 hour to obtain a wet material, wherein the water content in the wet material is 40wt%;

[0079] Step 3: Put the wet material into an extruder to prepare a cylindrical catalyst with a diameter of 3 mm and a length of 5-15 mm;

[0080] Step 4: Dry the cylindrical catalyst at 100°C for 1 hour;

[0081] Step 5: calcine the dried cylindrical catalyst at 400° C. for 4 h to obtain a molecular oxidation catalyst.

[0082] Embodiment 8:

[0083] A method for preparing a molecular oxidation catalyst comprises the following steps:

[0084] Step 1, pre-treating the pseudo-boehmite before use, wherein the pre-treatment method is as follows: taking 1000 mL of 0.8 g / L chromium formate solution to soak 100 g of pseudo-boehmite for 1 hour, filtering the soaked material, and drying at 100° C. for 2 hours to pre-treat the pseudo-boehmite;

[0085] 90 g of pretreated pseudo-boehmite, 3 g of starch, 2 g of nano-silicon dioxide, and 5 g of chromium formate were uniformly mixed in a mixer for 30 min to obtain a mixed solid material;

[0086] Step 2: Add deionized water to the mixed solid material and stir for 1 hour to obtain a wet material, wherein the water content in the wet material is 50wt%;

[0087] Step 3: Put the wet material into an extruder to prepare a cylindrical catalyst with a diameter of 3 mm and a length of 5-15 mm;

[0088] Step 4: Dry the cylindrical catalyst at 150°C for 0.5h;

[0089] Step 5: calcine the dried cylindrical catalyst at 450° C. for 3 h to obtain a molecular oxidation catalyst.

[0090] Embodiment 9:

[0091] A method for preparing a molecular oxidation catalyst comprises the following steps:

[0092] Step 1, pre-treating the pseudo-boehmite before use, the pre-treatment method is: taking 0.8g of chromium formate and adding it into a supercritical carbon dioxide reactor, adding 100g of pseudo-boehmite at the same time, and then introducing carbon dioxide gas, raising the temperature (45°C) and the pressure (30MPa) to a supercritical state, stirring and fully mixing and impregnating for 1 hour, cooling and reducing the pressure and collecting the material, that is, pre-treating the pseudo-boehmite;

[0093] 90 g of pretreated pseudo-boehmite, 3 g of starch, 2 g of nano-silicon dioxide, and 5 g of chromium formate were uniformly mixed in a mixer for 30 min to obtain a mixed solid material;

[0094] Step 2: Add deionized water to the mixed solid material and stir for 1 hour to obtain a wet material, wherein the water content in the wet material is 50wt%;

[0095] Step 3: Put the wet material into an extruder to prepare a cylindrical catalyst with a diameter of 3 mm and a length of 5-15 mm;

[0096] Step 4: Dry the cylindrical catalyst at 150°C for 0.5h;

[0097] Step 5: calcine the dried cylindrical catalyst at 450° C. for 3 h to obtain a molecular oxidation catalyst.

[0098] Catalytic tests were performed on the catalysts prepared in Examples 1 to 9, wherein the ozone concentration was 5 mg / L (relative to air), the fluidized bed was used to treat K3 wastewater with an initial COD concentration of 829.58 mg / L (the volume of K3 wastewater in the fluidized bed was 300 mL), and the treatment time was 2 h; the results are shown in Table 1:

[0099] Table 1

[0100] Sample group number Catalyst addition amount COD removal rate Example 1 1.00g 81.79％ Example 2 1.00g 90.89％ Example 3 1.00g 90.95％ Example 4 1.00g 88.75％ Example 5 1.00g 91.58％ Example 6 1.00g 95.58％ Example 7 1.00g 97.75％ Example 8 1.00g 96.12％ Example 9 1.00g 98.25％

[0101] The present invention illustrates the detailed method of the present invention through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned detailed method, that is, it does not mean that the present invention must rely on the above-mentioned detailed method to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent substitution of various raw materials of the product of the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A method for preparing a molecular oxidation catalyst, characterized in that: The following steps are involved: Step 1: Mixing: Mixing metal formate, pseudo-boehmite, auxiliary agent and toughening agent to obtain a mixed solid material; Step 2: stirring: adding the mixed solid material into deionized water and stirring to obtain a wet material; Step 3: Forming: forming the wet material by granulating equipment to obtain formed wet material; Step 4: Drying: Place the wet molded material in a high temperature furnace to dry; Step 5: Sintering: Continue to heat up and sinter the dried molding material to obtain a molecular oxidation catalyst.

2. The method for preparing a molecular oxidation catalyst according to claim 1, characterized in that: In the step 1, the metal formate salt is one or more of copper formate, manganese formate, iron formate, zinc formate, chromium formate, and molybdenum formate.

3. The method for preparing a molecular oxidation catalyst according to claim 1, characterized in that: In the step 1, the pseudo-boehmite is pretreated before use, and the pretreatment method is as follows: taking a formate metal salt solution with a concentration of 0.5 to 1 g / L to impregnate the pseudo-boehmite for 1 to 3 hours, filtering the impregnated material, and drying it at 100° C. for 2 to 3 hours to pretreat the pseudo-boehmite; the mass volume ratio of the pseudo-boehmite to the formate metal salt solution is 1 g:10 to 15 mL.

4. The method for preparing a molecular oxidation catalyst according to claim 1, characterized in that: In the step 1, the auxiliary agent is one or more of sesbania powder, starch, chitosan, and polyvinyl pyrrolidone.

5. The method for preparing a molecular oxidation catalyst according to claim 1, characterized in that: In the step 1, the toughening agent is one or more of nano-attapulgite, nano-kaolin, and nano-silicon dioxide.

6. The method for preparing a molecular oxidation catalyst according to claim 1, characterized in that: In the step 1, the mass ratio of the binder, auxiliary agent, toughening agent and metal formate is (50-90):(5-30):(2-8):(1-8):(1-10); and the mixing time is 0.5-5h.

7. The method for preparing a molecular oxidation catalyst according to claim 1, characterized in that: In the step 2, the water content in the wet material is 15-60wt%; and the stirring time is 0.5-4h.

8. The method for preparing a molecular oxidation catalyst according to claim 1, characterized in that: In the step three, the wet material is formed into a cylinder with a diameter of 1 mm to 8 mm and a length of 10 mm to 60 mm using a granulating device.

9. The method for preparing a molecular oxidation catalyst according to claim 1, characterized in that: In the step 4, the drying temperature is 40-250° C. and the drying time is 1-8 hours.

10. The method for preparing a molecular oxidation catalyst according to claim 1, characterized in that: In the step 5, the sintering temperature is 300-550° C. and the sintering time is 1-12 hours.