CN-121988341-A - Bimetallic composite catalyst and preparation method and application thereof

Abstract

The invention provides a bimetal composite catalyst and a preparation method and application thereof, wherein the preparation method comprises the steps of contacting smelting flue gas with the bimetal composite catalyst after plasma strengthening, wherein the smelting flue gas contains chlorobenzene and/or dioxin, the concentration of the chlorobenzene in the smelting flue gas is 50-500ppm under the condition that the smelting flue gas contains the chlorobenzene, and the concentration of the dioxin in the smelting flue gas is not higher than 20 ng TEQ/m 3 under the condition that the smelting flue gas contains the dioxin. The invention solves the technical problems that CVOCs degradation efficiency of chlorobenzene and the like is insufficient and synchronous and efficient degradation of chlorobenzene and dioxin is difficult to realize in common technology, and realizes efficient mineralization of chlorobenzene and synchronous realization of efficient adsorption and deep degradation of dioxin through multipath coupling.

Inventors

• SHEN FENGHUA
• LIU HUI
• LIU CHAOLONG
• YU JIE
• XIANG KAISONG
• CHAI LIYUAN

Assignees

• 中南大学

Dates

Publication Date

20260508

Application Date

20260130

Claims (10)

1. 1. The bimetal composite catalyst is characterized by being applied to the treatment of nonferrous metal smelting flue gas; The bimetallic composite catalyst is in an irregular particle shape and consists of a pseudo-boehmite carrier and manganese and copper elements loaded on the pseudo-boehmite carrier, wherein a compact and uniform mesoporous structure exists on the surface of the carrier, and the manganese and copper elements are cooperatively distributed on the surface of the carrier; The bimetallic composite catalyst has bimetallic loading of 1-10%, and the molar ratio of manganese element to copper element is 2-6:1.
2. 2. The bimetallic composite catalyst of claim 1, wherein the specific surface area is 200-300 m 2 /g and the average pore size is 3.0-10.0 nm.
3. 3. The bimetallic composite catalyst according to claim 1, wherein the bimetallic composite catalyst has a bimetallic loading of 1% -5% and a molar ratio of manganese element to copper element of 2-5:1.
4. 4. A method for preparing the bimetallic composite catalyst as claimed in any one of claims 1 to 3, comprising the steps of: mixing a manganese source and a copper source in a first solvent to obtain a bimetallic reagent; dispersing pseudo-boehmite in a second solvent to obtain an aluminum-containing reagent, wherein the ratio of manganese to copper elements in the total mass of the manganese source, the copper source and the pseudo-boehmite is 1-10%, and the molar ratio of manganese elements in the manganese source to copper elements in the copper source is 2-6:1; mixing the bimetallic reagent with the aluminum-containing reagent to obtain a precursor reagent; and stirring, aging and calcining the precursor reagent in sequence to obtain the bimetallic composite catalyst.
5. 5. The method of preparing a bimetallic composite catalyst of claim 4, wherein the manganese source comprises manganese acetate tetrahydrate and the copper source comprises copper sulfate pentahydrate.
6. 6. The method for preparing a bimetallic composite catalyst according to claim 4, wherein the temperature of the stirring treatment is 50-100 ℃, the duration of the stirring treatment is 1-5 hours, the temperature of the aging treatment is 10-50 ℃, the duration of the aging treatment is 10-20 hours, the temperature of the calcining treatment is 400-700 ℃, and the duration of the calcining treatment is 1-5 hours.
7. 7. Use of a bimetallic composite catalyst according to any one of claims 1-3 or prepared by a method of preparing a bimetallic composite catalyst according to any one of claims 4-6 in the treatment of non-ferrous metal smelting fumes, comprising the steps of: The smelting flue gas is contacted with the bimetal composite catalyst after being strengthened by plasma, wherein the smelting flue gas contains chlorobenzene and/or dioxin; In the case that the smelting flue gas contains chlorobenzene, the concentration of the chlorobenzene in the smelting flue gas is 50-500ppm; In the case that the smelting flue gas contains dioxin, the concentration of the dioxin in the smelting flue gas is not higher than 20 ng TEQ/m 3 .
8. 8. The use of a bimetallic composite catalyst in the treatment of nonferrous metal smelting flue gas according to claim 7, wherein the plasma discharge voltage during the smelting flue gas treatment is not lower than 16V.
9. 9. The use of a bimetallic composite catalyst in the treatment of nonferrous metal smelting flue gas according to claim 7, wherein the reaction space velocity in the smelting flue gas treatment process is 4000-12000 h -1 .
10. 10. The use of a bimetallic composite catalyst in the treatment of non-ferrous metal smelting flue gas according to claim 7, wherein the flow rate of the smelting flue gas during the smelting flue gas treatment is 0.5-10L/min, and the relationship between the bimetallic composite catalyst and the volume of the smelting flue gas is 0.1-1 g:10-500L.

Description

Bimetallic composite catalyst and preparation method and application thereof Technical Field The invention belongs to the technical field of flue gas treatment, and particularly relates to a bimetal composite catalyst, and a preparation method and application thereof. Background The regenerated nonferrous metal smelting has important significance in saving mineral resources and reducing energy consumption by carrying out secondary utilization on waste metal resources. However, this process also causes a complicated environmental pollution problem. The regeneration smelting process of different metals has different types and contents of harmful pollutants in the generated nonferrous metal smelting flue gas due to the differences of raw material compositions and process conditions, and the emission is very complicated. Wherein, the chlorine-containing volatile organic pollutant (CVOCs) is one of main pollutants, carbon and chlorine in the raw materials can generate various CVOCs during high-temperature smelting, and meanwhile, high-toxicity persistent organic pollutant dioxins (PCDD/Fs) can be generated. Specifically, under the common high-temperature smelting condition of 800-1200 ℃, carbon and chlorine in the raw materials are subjected to pyrolysis reaction to generate various CVOCs. Among them, chlorobenzene (such as monochlorobenzene, dichlorobenzene) occupies a relatively large amount in the effluent, and this kind of compound is not only highly toxic, but also has environmental durability, and constitutes a serious threat to the ecosystem and human health. In addition, dioxins (PCDD/Fs) possibly remaining in the raw materials or the waste residues are released with the smoke if they are not completely degraded at an insufficient temperature. In addition to raw material factors, process conditions play a key role in CVOCs production. Smelting temperature, oxygen concentration, residence time and the like can obviously influence the generation type and quantity of CVOCs. For example, in the range of 500-800 ℃, the production amount of chlorobenzene is high, and under the anoxic condition, i.e. the oxygen content is lower than 70 percent of the complete combustion requirement, incomplete combustion products such as chlorobenzene, chlorophenol and the like are more easily produced, and the products become precursors for synthesizing dioxin. In addition, the insufficient residence time of the flue gas in the high temperature zone may also exacerbate CVOCs production. At present, the national standard sets strict limit (0.5 ngTEQ/m 3) for dioxin and chlorobenzene substances discharged by all regenerated nonferrous metal enterprises. However, aiming at the treatment of CVOCs such as chlorobenzene in the flue gas, the prior art still faces the challenge of insufficient degradation efficiency, and the control effect on the accompanied dioxin pollutants is also not ideal. Therefore, developing pollution control technology capable of synchronously and efficiently degrading chlorobenzene and dioxin has become an urgent need for the treatment of regenerated nonferrous metal smelting pollution. Disclosure of Invention Aiming at solving the technical problems that CVOCs degradation efficiency of chlorobenzene and the like is insufficient and synchronous and efficient degradation of chlorobenzene and dioxin is difficult to achieve in the common technology, the invention provides a bimetal composite catalyst which is applied to non-ferrous metal smelting flue gas treatment; The bimetallic composite catalyst is in an irregular particle shape and consists of a pseudo-boehmite carrier and manganese and copper elements loaded on the pseudo-boehmite carrier, wherein a compact and uniform mesoporous structure exists on the surface of the carrier, and the manganese and copper elements are cooperatively distributed on the surface of the carrier; The bimetallic composite catalyst has bimetallic loading of 1-10%, and the molar ratio of manganese element to copper element is 2-6:1. Further, the specific surface area is 200-300 m 2/g, and the average pore diameter is 3.0-10.0 nm. Further, the bimetallic composite catalyst has a bimetallic loading of 1% -5%, and the molar ratio of manganese element to copper element is 2-5:1. The invention provides a preparation method of the bimetallic composite catalyst, which comprises the following steps: mixing a manganese source and a copper source in a first solvent to obtain a bimetallic reagent; dispersing pseudo-boehmite in a second solvent to obtain an aluminum-containing reagent, wherein the ratio of manganese to copper elements in the total mass of the manganese source, the copper source and the pseudo-boehmite is 1-10%, and the molar ratio of manganese elements in the manganese source to copper elements in the copper source is 2-6:1; mixing the bimetallic reagent with the aluminum-containing reagent to obtain a precursor reagent; and stirring, aging and calcining the precursor reagent