阅读说明：本技术 无钒改性锰基nh3-scr脱硝催化剂及其制法与应用 (Vanadium-free modified manganese-based NH3-SCR denitration catalyst and preparation method and application thereof ) 是由 李春晓 邱明英 王建华 张宇鑫 崔岩 任乐 于 2019-11-28 设计创作，主要内容包括：本发明提供一种无钒改性锰基NH-3-SCR脱硝催化剂及其制法与应用。以催化剂质量为100％计,该脱硝催化剂活性组分包含1.0-10.0wt％的MnO-2、0.1-12wt％的WO-3、0.1-9wt％的NiO、0wt％-0.3wt％的P-2O-5,且MnO-2质量大于NiO质量。该催化剂的制法包含：将各活性组分前驱体负载在载体上,经焙烧得到所述催化剂。该催化剂适用于烟气脱硝处理。使用该催化剂进行烟气脱硝处理的方法能实现在较低较宽的温度窗口,较高的SO-2浓度下长时间保持较高脱硝效率。本发明提供的催化剂具备在较宽的低温范围内具有良好催化脱硝效率的性能以及与V系催化剂相当的优异抗硫性能。(The invention provides vanadium-free modified manganese-based NH 3 -SCR denitration catalyst and preparation method and application thereof. The active component of the denitration catalyst comprises 1.0-10.0 wt% of MnO based on 100% of the mass of the catalyst 2 0.1 to 12 wt% of WO 3 0.1-9 wt% of NiO and 0-0.3 wt% of P 2 O 5 And MnO of 2 The mass is greater than the mass of NiO. The preparation method of the catalyst comprises the following steps: loading each active component precursor on a carrier, and roasting to obtain the catalyst. The catalyst is suitable for flue gas denitration treatment. Fume production using the catalystThe method for denitration treatment of gas can realize higher SO in a lower and wider temperature window 2 Higher denitration efficiency is kept for a long time under the concentration. The catalyst provided by the invention has good performance of catalyzing denitration efficiency in a wide low temperature range and excellent sulfur resistance equivalent to that of a V-type catalyst.)

1. Vanadium-free modified manganese-based NH₃-an SCR denitration catalyst, wherein the catalyst-supported active component contains MnO in an amount of 1.0 to 10.0 wt% based on 100% by mass of the catalyst₂0.1 to 12 wt% of WO₃0.1-9 wt% of NiO, 0-0.3 wt% of P₂O₅And MnO of₂Is greater than the mass of NiO.

2. According to the claimsThe denitration catalyst according to claim 1, wherein P is an active component supported on the catalyst₂O₅Has a mass of WO₃2.55% of the mass of (a).

3. The denitration catalyst of claim 1, wherein the NiO has a mass not exceeding MnO₂0.8 times of the mass.

4. The denitration catalyst according to claim 1, wherein the support of the catalyst is TiO₂。

5. The vanadium-free modified manganese-based NH as claimed in any one of claims 1 to 4₃-a method for preparing an SCR denitration catalyst, wherein the method comprises the steps of:

loading the raw materials of each active component on a carrier, and roasting to obtain the vanadium-free modified manganese-based NH₃-an SCR denitration catalyst;

wherein, the active component raw materials comprise 1.0-10.0 wt% of Mn source, 0.1-12 wt% of W source, 0.1-9 wt% of Ni source and 0-0.3 wt% of P source, and the mass of the Mn source is larger than that of the Ni source, based on the total mass of the carrier and the active component raw materials as 100%; wherein the mass of the Mn source is MnO₂Mass meter, W source mass WO₃Mass meter, Ni source mass as NiO mass, P source mass as P₂O₅And (4) measuring the mass.

6. The production method according to claim 5,

the Mn source in the active component raw material is manganese salt, wherein only manganese oxide enters the catalyst after the manganese salt is roasted;

the W source and the P source in the raw materials of the active components are phosphotungstic acid;

the Ni source in the raw materials of the active component is nickel salt, wherein only nickel oxide enters the catalyst after the nickel salt is roasted.

7. The production method according to claim 6, wherein,

the Mn source is manganese oxalate;

the Ni source is nickel oxalate.

8. The preparation method as claimed in claim 5, wherein the roasting temperature is 400-600 ℃ and the roasting time is 1-6 h.

9. A flue gas denitration treatment method, wherein the method uses the vanadium-free modified manganese-based NH as claimed in any one of claims 1 to 4₃-carrying out flue gas denitration treatment on the SCR denitration catalyst.

10. The flue gas denitration treatment method as claimed in claim 9, wherein the flue gas denitration treatment temperature is 120-300 ℃, and SO in the denitration treated flue gas₂The maximum concentration is 500 ppm.

Technical Field

The invention belongs to the technical field of low-temperature denitration catalytic materials, and relates to vanadium-free modified manganese-based NH₃-SCR denitration catalyst and preparation method and application thereof.

Background

Nitrogen oxides are a major atmospheric pollutant, with NO accounting for 90% of the total nitrogen oxides. The Selective Catalytic Reduction (SCR) technology is the most widely and mature denitration technology internationally, and NO is_xAnd NH₃Conversion to non-toxic N under oxygen-containing conditions and with the aid of catalysts₂And H₂O。

The commercial catalysts mainly used in industry at present are mostly V₂O₅-WO₃/TiO₂Or V₂O_5-MoO₃/TiO₂The operation temperature of the catalyst is 300-400 ℃, so that most industrial applications adopt a high-dust arrangement, and the high-dust arrangement places the denitration module before dust removal and desulfurization, which can greatly reduce the mechanical and chemical life of the SCR catalyst and greatly increase the denitration cost. The Mn-based catalyst has relatively better NH as a substitute catalyst for the V-based catalyst₃SCR low-temperature denitration activity, however, its sulfur resistance is poor. Compared with a single Mn oxide catalyst, the multi-element metal oxide catalyst formed by Mn-Ni synergy has improved sulfur resistance, but compared with a V-series catalyst, the sulfur resistance effect of the multi-element metal oxide catalyst can not meet the sulfur resistance requirement in the denitration process, so that the practical application of Mn in China is less at present. In order to reduce the effect of sulfur on the catalyst,the first-stage project of Tangshanfengda coking Co Ltd adopts a process route of waste heat recovery, dry desulphurization, dust removal and SCR denitration, SO that dust and SO are effectively reduced₂The influence on the catalyst greatly prolongs the service life of the catalyst, but the flue gas temperature is lower, and extremely high requirements are provided for the low-temperature denitration capability of the catalyst.

The coke oven gas generated by the coking process has low flue gas temperature and NO_xHigh content of SO₂Relatively low content. Current commercial catalyst V₂O₅-WO₃/TiO₂And V₂O_5-MoO₃/TiO₂The catalyst cannot be well applied due to the overhigh reaction temperature, and the Mn system comprises the prior multi-element metal oxide catalyst which is formed by Mn-Ni coordination, although the temperature requirement can be met, the application prospect is seriously restricted due to the poor sulfur resistance.

On one hand, in view of the dilemma that the demand of the prior art on the low-temperature catalytic environment is more urgent and the existing low-temperature catalyst cannot be popularized and used due to poor sulfur resistance, and on the other hand, in view of the problem of toxic component pollution of the V-series catalyst, the research on the V-free low-temperature sulfur-resistant catalyst which has good catalytic denitration efficiency and good sulfur resistance under the low-temperature condition has important significance.

Disclosure of Invention

The invention aims to provide low-temperature sulfur-resistant NH without V₃An SCR denitration catalyst having excellent catalytic denitration efficiency in a wide low temperature range and having sulfur resistance comparable to that of a V-based catalyst.

In order to achieve the aim, the invention provides vanadium-free modified manganese-based NH₃An SCR denitration catalyst in which the catalyst-supported active component contains MnO in an amount of 1.0 to 10.0 wt% based on 100% of the total mass of the catalyst (i.e., based on 100% of the total mass of the support and each component supported on the support)₂0.1 to 12 wt% of WO₃0.1-9 wt% of NiO and 0-0.3 wt% of P₂O₅。

In the above denitration catalyst, when the phosphorus element is added (i.e., when the mass of the carrier of the catalyst is 100%)，P₂O₅When the content of (b) is less than 0.3 wt%), the vanadium-free modified manganese-based NH can be modified by the synergy of the four Mn-W-Ni-P elements₃The SCR low-temperature activity and the catalytic denitration capability of the SCR denitration catalyst have further promotion effects.

In the above denitration catalyst, preferably, P in the active component supported by the catalyst is 100% by mass of the total catalyst₂O₅Mass is WO₃2.55 percent of the total weight. (i.e., the P element accounts for 1.4% of the W element by mass.)

In the above denitration catalyst, preferably, the mass of NiO does not exceed MnO₂0.8 times of the mass. Controlling the quality of NiO not to exceed MnO₂0.8 times of the mass, contributes to further and obviously improving the denitration performance of the catalyst, and has more than 75 percent of NO at the temperature of 120-300 DEG C_xAnd (4) removing efficiency.

In the above denitration catalyst, preferably, the carrier of the catalyst is TiO₂。

In one embodiment of the above denitration catalyst, the active component raw material of the catalyst comprises 1.0-10.0 wt% of a Mn source, 0.1-12 wt% of a W source, 0.1-9 wt% of a Ni source, 0-0.3 wt% of a P source, and the mass of the Mn source is greater than the mass of the Ni source, based on 100% of the total mass of the support raw material and the active component raw material of the catalyst; wherein the mass of Mn source in the raw materials of the active component is MnO₂Mass meter, W source mass WO₃Mass meter, Ni source mass as NiO mass, P source mass as P₂O₅And (4) measuring the mass. The mass of the P source is preferably 2.55% of the mass of the W source (i.e., P element mass is 1.4% of W element mass), where W source mass is WO₃Mass meter, P source mass, and P₂O₅And (4) measuring the mass. The mass of the Ni source is preferably not more than 0.8 times the mass of the Mn source (the mass of the Mn source is MnO)₂Mass, Ni source mass in NiO mass). The support of the catalyst is preferably TiO₂。

Mn source in MnO₂Mass meter, i.e. mass of Mn Source MnO producible with the Mn Source₂The amount of Mn element in the Mn source is considered herein to be equal to the MnO that the Mn source can produce₂The amount of medium Mn element; quality of W source WO₃Mass meter, i.e. mass of W source WO producible with this W source₃The amount of W element in the W source is considered herein to be equal to the amount of WO that the Wn source can produce₃The amount of the medium W element; the mass of the Ni source is calculated as the mass of NiO, i.e., the mass of the Ni source is calculated as the mass of NiO that can be produced by the Ni source, and the amount of Ni element in the Ni source is considered herein to be equal to the amount of Ni element in NiO that can be produced by the Ni source; p source quality with P₂O₅Mass meter, i.e. the mass of a P source with P that the P source can produce₂O₅Is considered herein to be the amount of P element in the P source equal to the P that the P source is capable of producing₂O₅The amount of the P element.

In the above-mentioned embodiment of the denitration catalyst, when the phosphorus element is added, that is, the active component supported by the catalyst contains MnO₂、WO₃NiO and P₂O₅When the total mass of the carrier raw material and the active component raw material of the catalyst is 100 percent and the content of the P source is less than 0.3wt percent, the synergetic effect of the four elements of Mn-W-Ni-P on vanadium-free modified manganese-based NH can be realized₃The SCR low-temperature activity and the catalytic denitration capability of the SCR denitration catalyst have further promotion effects. When the mass of the Ni source is controlled to be not more than 0.8 times of the mass of the Mn source, the denitration performance of the catalyst is further remarkably improved, and the NOx removal efficiency is over 75 percent at the temperature of 300 ℃ below 120 ℃.

The invention also provides the vanadium-free modified manganese-based NH₃-a method for preparing an SCR denitration catalyst, wherein the method comprises the steps of:

loading the raw materials of each active component on a carrier, and roasting to obtain the vanadium-free modified manganese-based NH₃-an SCR denitration catalyst;

the active component raw materials comprise 1.0-10.0 wt% of Mn source, 0.1-12 wt% of W source, 0.1-9 wt% of Ni source and 0-0.3 wt% of P source, wherein the total mass of the carrier and the active component raw materials is 100%, and the mass of the Mn source is larger than that of the Ni source; wherein the mass of the Mn source is MnO₂Mass meter, W source mass WO₃Mass meter, Ni source mass as NiO mass, P source mass as P₂O₅And (4) measuring the mass.

In the above production method, it is preferable that the Mn source (i.e., MnO) in the raw material for the active component₂The active component precursor) is manganese salt, wherein only manganese oxide enters the catalyst after the manganese salt is roasted; such as manganese oxalate.

In the above-mentioned production method, preferably, the W source (i.e., WO) in the raw material of the active ingredient₃Active component precursor) is phosphotungstic acid.

In the above preparation method, preferably, the Ni source (i.e., NiO active component precursor) in the active component raw material is a nickel salt, wherein only the oxide of nickel enters the catalyst after the nickel salt is calcined; such as nickel oxalate; nickel nitrate is generally not the preferred nickel salt because of the explosion hazard of nickel nitrate in the reaction.

In the above production method, preferably, the Mn source (i.e., P) in the raw material of the active component₂O₅Active component precursor) is phosphotungstic acid.

In the above production method, preferably, the active component raw materials include a Mn source, a Ni source, and phosphotungstic acid.

In the preparation method, preferably, the roasting temperature is 400-600 ℃, and the roasting time is 1-6 h.

In the above production method, it is preferable to perform drying before performing firing. For example, drying may be carried out at 105 ℃ for 8-24 h.

In the above preparation method, preferably, the loading of each active ingredient raw material on the carrier is realized by: preparing a solution of each active component raw material, and loading the solution of each active component raw material on a carrier by adopting an impregnation method; wherein, the one-step impregnation method or the step-by-step impregnation method can be adopted.

In one embodiment, the vanadium-free modified manganese-based NH is₃The preparation method of the SCR denitration catalyst includes: dissolving a Mn source, a Ni source and phosphotungstic acid in deionized water at 40-80 ℃ to obtain a steeping liquor; then adding TiO into the impregnating solution₂The carrier is stirred to be viscous; baking the mixture at the temperature of 400-600 ℃ for 1 to 6 hours after drying to obtain the vanadium-free modified manganeseRadical NH₃-an SCR denitration catalyst.

In the above application, preferably, the flue gas is coke oven flue gas. The coke oven flue gas has SO₂Relatively low concentration of NO_xHigh concentration and low smoke temperature, the vanadium-free modified manganese-based NH provided by the invention₃The SCR denitration catalyst has good sulfur resistance and good low-temperature SCR activity, and has great advantages in coke oven smoke treatment.

The invention also provides a flue gas denitration treatment method, wherein the vanadium-free modified manganese-based NH is used in the method₃-carrying out flue gas denitration treatment on the SCR denitration catalyst.

In the above method for denitration treatment of flue gas, preferably, the temperature for denitration treatment of flue gas is 120-.

In the above flue gas denitration treatment method, preferably, SO in the denitration treated flue gas₂The maximum concentration is 500 ppm. Using the above vanadium-free modified manganese-based NH₃The denitration treatment of the flue gas by the SCR denitration catalyst can be carried out within the range of 120-300 ℃ and SO₂In the maximum concentration range of 500ppm, a high denitration efficiency is achieved for a long time (for example, 72 hours or more).

The invention aims at the research and development of a denitration catalyst without V from the viewpoint of having sulfur resistance and low-temperature denitration performance, and firstly proposes to contain MnO₂-WO₃Vanadium-free catalyst comprising a composite oxide containing NiO as active component and further comprising MnO₂-WO₃-NiO-P₂O₅A vanadium-free catalyst containing the composite oxide as an active component. Compared with the prior art, the technical scheme provided by the invention has the following beneficial technical effects:

1. the invention provides vanadium-free modified manganese-based NH₃The SCR denitration catalyst has good low-temperature activity and higher NOx removal efficiency at the temperature of 120-300 ℃.

2. The invention provides vanadium-free modified manganese-based NH₃The SCR denitration catalyst has better sulfur resistance and can basically reach commercial V₂O₅Sulfur resistance level of the catalyst.

3. The invention provides vanadium-free modified manganese-based NH₃The preparation method of the SCR denitration catalyst has simple process and easy industrial popularization.

4. The invention provides vanadium-free modified manganese-based NH₃The SCR denitration catalyst has the sulfur resistance of an industrial V-series catalyst and a lower denitration temperature window, does not contain V, and greatly reduces the toxicity of the catalyst and the harm to the environment.

5. The invention provides vanadium-free modified manganese-based NH₃The SCR denitration catalyst utilizes the synergistic effect of three elements of Mn-W-Ni to realize the improvement of the low-temperature denitration activity and the sulfur resistance of the catalyst, and has obvious advantages compared with the performance of a Mn-Ni and Mn-W dual-active component catalyst.

6. The flue gas denitration treatment method provided by the invention can realize a relatively wide temperature window and a relatively high SO₂The high denitration efficiency is kept for a long time under the concentration.

Drawings

Figure 1 is an XRD pattern of the catalyst provided in example 1.

FIG. 2 shows the modified Mn-based NH without V, provided in examples 1 to 3₃-NOx removal rate results plot for SCR denitration catalyst.

Fig. 3 is a graph showing the effect of NOx removal efficiency of each catalyst in experimental example 2.

Fig. 4 is a graph showing the effect of NOx removal efficiency of each catalyst in experimental example 3.

Detailed Description

The technical solutions of the present invention will be described in detail below in order to clearly understand the technical features, objects, and advantages of the present invention, but the present invention is not limited to the practical scope of the present invention.

Example 1

This example provides a vanadium-free modified manganese-based NH₃SCR denitration catalyst, the catalyst being made of TiO₂As a carrier, the catalyst is used in a manner that the total mass of the catalyst is 100 percent (namely the total mass of the carrier and the mass of active components which can be prepared by the raw materials of the active components theoretically is 100 percent)The agent-supported active component contains MnO in a theoretical amount of 8 wt%₂WO 6% by weight of theory₃NiO with theoretical content of 2 wt% and trace P₂O₅Wherein the theoretical mass of phosphorus element is about 1.4% of the theoretical mass of W element (i.e., P)₂O₅Theoretical mass of WO₃2.55% of theory, i.e. 0.2 wt% of the total mass); the catalyst is prepared by the following method:

weighing 2.63g of manganese oxalate, 1.31g of phosphotungstic acid, 0.79g of nickel oxalate and 16.80g of TiO according to the theoretical content of each active component in the catalyst₂(ii) a Adding 2.63g of manganese oxalate, 1.31g of phosphotungstic acid and 0.79g of nickel oxalate into 50ml of deionized water, and heating the mixture in a water bath at the temperature of 60 ℃ until the mixture is completely dissolved to obtain a steeping liquor; 16.80g of TiO was added to the impregnation solution₂Fully stirring the mixture to be viscous, and then drying the mixture in a drying oven at 105 ℃ for 12 hours; roasting the dried product in a muffle furnace at 500 ℃ for 3h to obtain vanadium-free modified manganese-based NH₃SCR denitration catalyst, 8Mn6W2Ni/TiO₂。

The vanadium-free modified manganese-based NH provided in this example₃XRD results of the SCR denitration catalyst are shown in fig. 1. From FIG. 1, only TiO in the anatase modification can be observed₂From this, it is known that the active component is present in the catalyst TiO₂The support surface is highly dispersed or in an amorphous state.

Example 2

This example provides a vanadium-free modified manganese-based NH₃SCR denitration catalyst, the catalyst being made of TiO₂As support, the catalyst supports an active component comprising MnO in a theoretical amount of 8 wt%, based on 100% of the theoretical total mass of the catalyst (i.e. based on 100% of the total mass of the support plus the mass of active component which the starting material of the active component could theoretically be prepared from)₂WO 6% by weight of theory₃NiO with theoretical content of 1 wt% and trace P₂O₅Wherein the theoretical mass of phosphorus element is about 1.4% of the theoretical mass of W element (i.e., P)₂O₅Theoretical mass of WO₃2.55% of theory); the catalyst is prepared by the following method:

take 2.6Adding 3g of manganese oxalate, 1.31g of phosphotungstic acid and 0.40g of nickel oxalate into 50ml of deionized water, and heating the mixture in a water bath at the temperature of 60 ℃ until the mixture is completely dissolved to obtain a steeping liquor; 17.00g of TiO was added to the impregnation solution₂Fully stirring the mixture to be viscous, and then drying the mixture in a drying oven at 105 ℃ for 12 hours; roasting the dried product in a muffle furnace at 500 ℃ for 3h to obtain vanadium-free modified manganese-based NH₃SCR denitration catalyst, 8Mn6W1Ni/TiO₂。

Example 3

This example provides a vanadium-free modified manganese-based NH₃SCR denitration catalyst, the catalyst being made of TiO₂As support, the catalyst supports an active component comprising MnO in a theoretical amount of 8 wt%, based on 100% of the theoretical total mass of the catalyst (i.e. based on 100% of the total mass of the support plus the mass of active component which the starting material of the active component could theoretically be prepared from)₂WO 6% by weight of theory₃NiO with theoretical content of 4 wt% and trace P₂O₅Wherein the theoretical mass of phosphorus element is about 1.4% of the theoretical mass of W element (i.e., P)₂O₅Theoretical mass of WO₃2.55% of theory); the catalyst is prepared by the following method:

adding 2.63g of manganese oxalate, 1.31g of phosphotungstic acid and 1.58g of nickel oxalate into 50ml of deionized water, and heating the mixture in a water bath at the temperature of 60 ℃ until the mixture is completely dissolved to obtain a steeping liquor; 16.40g of TiO was added to the impregnation solution₂Fully stirring the mixture to be viscous, and then drying the mixture in a drying oven at 105 ℃ for 12 hours; roasting the dried product in a muffle furnace at 500 ℃ for 3h to obtain vanadium-free modified manganese-based NH₃SCR denitration catalyst, 8Mn6W4Ni/TiO₂。

Example 4

This example provides a vanadium-free modified manganese-based NH₃SCR denitration catalyst, the catalyst being made of TiO₂As support, the catalyst supports an active component comprising MnO in a theoretical amount of 8 wt%, based on 100% of the theoretical total mass of the catalyst (i.e. based on 100% of the total mass of the support plus the mass of active component which the starting material of the active component could theoretically be prepared from)₂Theoretical content ofWO 6 wt.%₃NiO with theoretical content of 3 wt% and trace P₂O₅Wherein the theoretical mass of phosphorus element is about 1.4% of the theoretical mass of W element (i.e., P)₂O₅Theoretical mass of WO₃2.55% of theory); the catalyst is prepared by the following method:

adding 2.63g of manganese oxalate, 1.31g of phosphotungstic acid and 1.19g of nickel oxalate into 50ml of deionized water, and heating the mixture in a water bath at the temperature of 60 ℃ until the mixture is completely dissolved to obtain a steeping liquor; 16.40g of TiO was added to the impregnation solution₂Fully stirring the mixture to be viscous, and then drying the mixture in a drying oven at 105 ℃ for 12 hours; roasting the dried product in a muffle furnace at 500 ℃ for 3h to obtain vanadium-free modified manganese-based NH₃SCR denitration catalyst, 8Mn6W3Ni/TiO₂。

Example 5

This example provides a vanadium-free modified manganese-based NH₃SCR denitration catalyst, the catalyst being made of TiO₂As support, the catalyst supports an active component comprising MnO in a theoretical amount of 8 wt%, based on 100% of the theoretical total mass of the catalyst (i.e. based on 100% of the total mass of the support plus the mass of active component which the starting material of the active component could theoretically be prepared from)₂WO 6% by weight of theory₃NiO with theoretical content of 4 wt% and trace P₂O₅Wherein the theoretical mass of phosphorus element is about 1.4% of the theoretical mass of W element (i.e., P)₂O₅Theoretical mass of WO₃2.55% of theory); the catalyst is prepared by the following method:

adding 2.63g of manganese oxalate, 1.31g of phosphotungstic acid and 2.53g of nickel oxalate into 50ml of deionized water, and heating the mixture in a water bath at the temperature of 60 ℃ until the mixture is completely dissolved to obtain a steeping liquor; 16.40g of TiO was added to the impregnation solution₂Fully stirring the mixture to be viscous, and then drying the mixture in a drying oven at 105 ℃ for 12 hours; roasting the dried product in a muffle furnace at 500 ℃ for 3h to obtain vanadium-free modified manganese-based NH₃SCR denitration catalyst, 8Mn6W6.4Ni/TiO₂。

Comparative example 1

This comparative example provides a vanadium-free modified manganese-based NH₃SCR denitration catalyst, the catalyst being made of TiO₂As support, the catalyst supports an active component comprising MnO in a theoretical amount of 8 wt%, based on 100% of the theoretical total mass of the catalyst (i.e. based on 100% of the total mass of the support plus the mass of active component which the starting material of the active component could theoretically be prepared from)₂WO 6% by weight of theory₃NiO with theoretical content of 4 wt% and trace P₂O₅Wherein the theoretical mass of phosphorus element is about 1.4% of the theoretical mass of W element (i.e., P)₂O₅Theoretical mass of WO₃2.55% of theory); the catalyst is prepared by the following method:

adding 2.63g of manganese oxalate, 1.31g of phosphotungstic acid and 3.16g of nickel oxalate into 50ml of deionized water, and heating the mixture in a water bath at the temperature of 60 ℃ until the mixture is completely dissolved to obtain a steeping liquor; 16.40g of TiO was added to the impregnation solution₂Fully stirring the mixture to be viscous, and then drying the mixture in a drying oven at 105 ℃ for 12 hours; roasting the dried product in a muffle furnace at 500 ℃ for 3h to obtain vanadium-free modified manganese-based NH₃SCR denitration catalyst, 8Mn6W8Ni/TiO₂。

Comparative example 2

This comparative example provides a modified manganese-based NH₃SCR denitration catalyst, the catalyst being made of TiO₂As support, the catalyst supports an active component comprising MnO in a theoretical amount of 8 wt%, based on 100% of the theoretical total mass of the catalyst (i.e. based on 100% of the total mass of the support plus the mass of active component which the starting material of the active component could theoretically be prepared from)₂NiO with the theoretical content of 2 wt%; the catalyst is prepared by the following method:

adding 2.63g of manganese oxalate and 0.79g of nickel oxalate into deionized water, and heating the mixture in a water bath at 60 ℃ until the mixture is completely dissolved to obtain a steeping liquor; 16.80g of TiO was added to the impregnation solution₂Fully stirring the mixture to be viscous, and then drying the mixture in a drying oven at 105 ℃ for 12 hours; baking the dried product in a muffle furnace at 500 ℃ for 3h to obtain modified manganese-based NH₃SCR denitration catalyst, noted Mn-Ni.

Comparative example 3

This comparative example provides a modified manganese-based NH₃SCR denitration catalyst, the catalyst being made of TiO₂As support, the catalyst supports an active component comprising MnO in a theoretical amount of 8 wt%, based on 100% of the theoretical total mass of the catalyst (i.e. based on 100% of the total mass of the support plus the mass of active component which the starting material of the active component could theoretically be prepared from)₂WO 6% by weight of theory₃(ii) a The catalyst is prepared by the following method:

adding 2.63g of manganese oxalate and 1.47g of ammonium tungstate into deionized water, and heating the mixture in a water bath at 60 ℃ until the mixture is completely dissolved to obtain impregnation liquid; 16.80g of TiO was added to the impregnation solution₂Fully stirring the mixture to be viscous, and then drying the mixture in a drying oven at 105 ℃ for 12 hours; baking the dried product in a muffle furnace at 500 ℃ for 3h to obtain modified manganese-based NH₃-SCR denitration catalyst, denoted as Mn-W.

Comparative example 4

This comparative example provides a modified manganese-based NH₃SCR denitration catalyst, the catalyst being made of TiO₂As support, the catalyst supports an active component comprising MnO in a theoretical amount of 8 wt%, based on 100% of the theoretical total mass of the catalyst (i.e. based on 100% of the total mass of the support plus the mass of active component which the starting material of the active component could theoretically be prepared from)₂0.2% by weight of P₂O₅(ii) a The catalyst is prepared by the following method:

adding 2.63g of manganese oxalate and 0.065g of triammonium phosphate into deionized water, and heating the mixture in a water bath at 60 ℃ until the manganese oxalate and the triammonium phosphate are completely dissolved to obtain a steeping fluid; 16.80g of TiO was added to the impregnation solution₂Fully stirring the mixture to be viscous, and then drying the mixture in a drying oven at 105 ℃ for 12 hours; baking the dried product in a muffle furnace at 500 ℃ for 3h to obtain modified manganese-based NH₃-SCR denitration catalyst, denoted as Mn-P.

Experimental example 1

The vanadium-free modified manganese-based NH provided in examples 1 to 5 and comparative example 1 were tested separately₃Denitration ability of SCR denitration catalyst at 120-_xRemoval rate), specific testThe conditions were as follows:

the concentration of NO in the flue gas to be treated is 700ppm, NO and NH₃In a volume ratio of 1:1, O₂The concentration of (A) is 5 vol%, the remainder is N₂(ii) a The total airspeed of the flue gas to be treated is 30000h^-1。

The test results are shown in FIG. 2, and it can be seen from FIG. 2 that the vanadium-free modified manganese-based NH provided in examples 1 to 5₃The SCR denitration catalyst has higher NO under the conditions of 120-300 DEG C_xRemoval rate, i.e., vanadium-free modified manganese-based NH provided in examples 1-3₃The SCR denitration catalyst has excellent low-temperature denitration performance and a large temperature window, and particularly, the denitration catalysts provided in examples 1 and 2 have more than 80% of NO within the range of 120 ℃ and 300 DEG C_xAnd (4) removing rate.

Example 1 provides vanadium-free modified manganese-based NH₃SCR denitration catalyst NiO of MnO mass₂0.25 times of the mass, modified manganese-based NH without vanadium as provided in example 2₃SCR denitration catalyst NiO of MnO mass₂0.125 times of the mass, example 3 provides a vanadium-free modified manganese-based NH₃SCR denitration catalyst NiO of MnO mass₂0.5 times of the mass, example 4 provides a vanadium-free modified manganese-based NH₃SCR denitration catalyst NiO of MnO mass₂0.375 times of the mass, example 5 provides a vanadium-free modified manganese-based NH₃SCR denitration catalyst NiO of MnO mass₂0.8 times of the mass, modified manganese-based NH without vanadium as provided in comparative example 1₃SCR denitration catalyst NiO of MnO mass₂1 time of the mass.

Vanadium-free modified manganese-based NH as provided by examples 1-5 and comparative example 1₃The comparison of the test results of the denitration performance of the SCR denitration catalyst shows that after the Ni content is reduced, the denitration performance of the catalyst is slightly reduced in a low-temperature section (120-180 ℃), and the medium-temperature and high-temperature sections are hardly affected.

Vanadium-free modified manganese-based NH provided by examples 1-5, comparative example 1₃The SCR denitration catalyst has a certain negative effect on the catalyst effect due to the fact that the Ni content is too high, and the denitration performance of the whole section of the catalyst is reduced.

Experimental example 2

Test example 1 provides vanadium-free modified manganese-based NH₃SCR denitration catalyst, Mn-Ni catalyst provided in comparative example 2, Mn-W catalyst provided in comparative example 3, and Cilihua V₂O₅The sulfur-resistant and water-resistant capability of a commercial low-temperature SCR catalyst (FXLBMF3-800) at the temperature of 200 ℃ is tested under the following specific test conditions:

the concentration of NO in the flue gas to be treated is 700ppm, NO and NH₃In a volume ratio of 1:1, O₂In a concentration of 5 vol% and SO₂The concentration is 500ppm, H₂The concentration of O is 10 vol%, and the rest is N₂(ii) a The total airspeed of the flue gas to be treated is 30000h^-1Test for NO within 72 hours_xThe variation of the removal rate.

The results are shown in FIG. 3, which shows that the vanadium-free modified manganese-based NH provided in example 1₃The sulfur resistance of the SCR denitration catalyst (marked as Mn-Ni-W in figure 3) is stronger than that of the traditional V-based catalyst (marked as V in figure 3)₂O₅) And (4) the equivalent. The sulfur resistance of both Mn-Ni and Mn-W catalysts is not as good as that of Mn-W-Ni three-component catalysts and traditional V-based catalysts; in addition, it can be seen from fig. 3 that the Ni element has a more significant reinforcing effect on the sulfur resistance of the catalyst than the W element.

Experimental example 3

Test example 1 provides vanadium-free modified manganese-based NH₃SCR denitration catalyst, Mn-Ni catalyst provided in comparative example 2, Mn-W catalyst provided in comparative example 3, Mn-P catalyst provided in comparative example 4, and Cilihua V₂O₅Denitration capability (namely NO) of base commercial low-temperature SCR catalyst (FXLBMF3-800) at the conditions of 120 ℃ and 300 DEG C_xRemoval rate), the specific test conditions were as follows:

the concentration of NO in the flue gas to be treated is 700ppm, NO and NH₃In a volume ratio of 1:1, O₂The concentration of (A) is 5 vol%, the remainder is N₂(ii) a The total airspeed of the flue gas to be treated is 30000h^-1。

The test results are shown in FIG. 4, it can be seen that the Mn-based catalyst has an activation temperature significantly lower than that of the V-based catalyst, W in the Mn-based catalyst has the function of widening the catalytic temperature window, and Ni reduces the catalytic activityDenitration efficiency of the agent under high temperature condition. The Mn-W-Ni elements in the catalyst have obvious synergistic effect. Comparative example 1 provides vanadium-free modified manganese-based NH₃The denitration abilities of the Mn-W-Ni-P catalyst provided by the SCR denitration catalyst, the Mn-Ni catalyst provided by the comparative example 2, the Mn-W catalyst provided by the comparative example 3 and the Mn-P catalyst provided by the comparative example 4 under the condition of 120-300 ℃ can be seen that the Mn-W-Ni-P elements in the catalyst have obvious synergistic effects.

Experimental example 4

The vanadium-free modified manganese-based NH provided in example 1 was taken₃SCR denitration catalyst, subjected to ICP (inductively coupled plasma spectrometer) detection, the results of which are given in table 1 below.

TABLE 1

As can be seen from Table 1, the ICP measurement result is equivalent to the theoretical mass (MnO) in example 1₂ 8wt％、NiO 2wt％、WO₃6wt％、P₂O₅0.2 wt.%) was substantially identical, which in one aspect may illustrate the vanadium-free modified manganese-based NH provided in example 1₃-SCR denitration catalyst contains MnO₂、NiO、WO₃、P₂O₅On the other hand, the prepared vanadium-free modified manganese-based NH can be illustrated₃MnO in SCR denitration catalyst₂、NiO、WO₃、P₂O₅The theoretical content of (b) is similar to the actual content. It is also demonstrated that the performance tests of the catalysts in the above experimental examples 1 to 3 are of practical significance.