阅读说明：本技术 一种钌系高抗水硫性的烧结烟气低温脱硝催化剂的制备方法 (Preparation method of ruthenium-based high-water-sulfur-resistance sintering flue gas low-temperature denitration catalyst ) 是由 余正伟 任志祥 龙红明 张洪亮 黄�俊 陈环 李澳 孟庆民 春铁军 魏汝飞 王平 于 2021-08-17 设计创作，主要内容包括：本发明公开了一种钌系高抗水硫性的烧结烟气低温脱硝催化剂的制备方法,涉及脱硝催化剂制备技术领域。本发明的一种钌系高抗水硫性的烧结烟气低温脱硝催化剂的制备方法,采用湿共浸渍法以TiO-(2)为载体浸渍负载由铈化合物、锰化合物和钌化合物配制成的活性组分溶液A,再通过焙烧得到RCMT催化剂,其中RuO-(x)的添加大幅提升了RCMT催化剂的抗水硫性能,为推进钢铁工业超低温脱硝做出贡献；采用低的铈锰负载量和一步浸渍焙烧,相比于以前高铈锰负载量以及分两步浸渍焙烧制备出来的RCMT催化剂的低温NH-(3)-SCR效果差不多,且工序简单,抗水硫性能提升较大；同时催化剂制备方法简单,成本代价低,适合工业化大批量制备。(The invention discloses a preparation method of a ruthenium-based high-water-sulfur-resistance sintering flue gas low-temperature denitration catalyst, and relates to the technical field of denitration catalyst preparation. The invention relates to a preparation method of a ruthenium-based high-water-sulfur-resistance sintering flue gas low-temperature denitration catalyst, which adopts a wet co-impregnation method and TiO 2 Impregnating and loading an active component solution A prepared from a cerium compound, a manganese compound and a ruthenium compound into a carrier, and roasting to obtain the RCMT catalyst, wherein RuO is x The addition of the catalyst greatly improves the water and sulfur resistance of the RCMT catalyst, and contributes to the promotion of ultralow temperature denitration in the steel industry; adopts low cerium manganese loading and one-step impregnation roasting, compared with the low-temperature NH of the RCMT catalyst prepared by high cerium manganese loading and two-step impregnation roasting 3 SCR is almost effective, andthe process is simple, and the water and sulfur resistance is greatly improved; meanwhile, the catalyst is simple in preparation method, low in cost and suitable for industrial mass preparation.)

1. A preparation method of a ruthenium-based high-water-sulfur-resistance sintering flue gas low-temperature denitration catalyst is characterized by comprising the following steps of:

preparing an active component solution A from a cerium compound, a manganese compound, a ruthenium compound and deionized water;

step two, adopting a wet co-impregnation method to prepare TiO₂To be loadedThe solution A in the first step is impregnated and loaded, and RuO is obtained by roasting_x-CeO_x-MnO_x/TiO₂A catalyst.

2. The preparation method of the ruthenium-based high-water-sulfur-resistance low-temperature denitration catalyst for the sintering flue gas according to claim 1, which is characterized by comprising the following steps of: in the first step, the cerium compound, the manganese compound and the ruthenium compound are respectively cerium nitrate hexahydrate, manganese nitrate and ruthenium nitrosyl nitrate.

3. The preparation method of the ruthenium-based high-water-sulfur-resistance low-temperature denitration catalyst for the sintering flue gas according to claim 1, which is characterized by comprising the following steps of: in the second step, the wet co-impregnation method comprises the following steps:

s1, stirring the weighed active component solution A vigorously for 5 minutes at room temperature;

s2, weighing anatase TiO₂The powder was slowly added to the active ingredient solution a being vigorously stirred for 1 hour to obtain a mixture solution.

4. The preparation method of the ruthenium-based high-water-sulfur-resistance low-temperature denitration catalyst for the sintering flue gas according to claim 3, which is characterized by comprising the following steps of: and S2, heating the obtained mixture solution in a magnetic stirrer with a heat collection function at 60 ℃ and stirring vigorously until the mixture solution is basically evaporated to dryness to obtain a mixture solid product.

5. The preparation method of the ruthenium-based high-water-sulfur-resistance low-temperature denitration catalyst for the sintering flue gas according to claim 4, which is characterized by comprising the following steps of: drying the mixture solid product in a drying oven at 110 ℃ for one night, then roasting the mixture solid product in a muffle furnace at room temperature and filled with air, and obtaining RuO after roasting_x-CeO_x-MnO_x/TiO₂A catalyst product.

6. The preparation method of the ruthenium-based high-water-sulfur-resistance low-temperature denitration catalyst for the sintering flue gas according to claim 5, which is characterized by comprising the following steps of: and roasting the solid product of the mixture in a muffle furnace, heating to 300-550 ℃ at a heating rate of 5 ℃/min, and roasting for 3-5 hours.

7. The preparation method of the ruthenium based high water and sulfur resistance sintering flue gas low temperature denitration catalyst according to any one of claims 1 to 6, characterized in that: the active component solution A is prepared from cerium nitrate hexahydrate, a 50% manganese nitrate solution and a ruthenium nitrosyl nitrate solution.

8. The preparation method of the ruthenium-based high-water-sulfur-resistance low-temperature denitration catalyst for the sintering flue gas according to claim 1, which is characterized by comprising the following steps of: the RuO_xThe addition amount of the CeO is 0.5-3 percent_x2-5% of MnO_x5-8% of TiO₂87-89.5 percent; in the mass ratio of the actual metal elements, Ru accounts for 0.38-2.28%, Ce accounts for 1.63-4.1%, Mn accounts for 3.16-5.06%, and Ti accounts for 52.2-53.7%.

Technical Field

The invention relates to the technical field of preparation of denitration catalysts, in particular to a preparation method of a ruthenium-based high-water-sulfur-resistance sintering flue gas low-temperature denitration catalyst.

Background

At present, the flue gas denitration technology mainly adopts a Selective Catalytic Reduction (SCR) method, a selective non-catalytic reduction (SNCR) method, an SCR/SNCR mixed method technology and the like. SNCR has stronger temperature dependence and lower denitration rate (only 25-40%), and Selective Catalytic Reduction (SCR) has been widely applied in many countries with strict flue gas emission standard and can meet the higher requirement of NO_xEmission standards are considered to be the most economical and reliable denitration technology at present.

CeO_x-MnO_x/TiO₂The SCR denitration catalyst is a sintering flue gas low-temperature denitration catalyst with the greatest potential at present, wherein cerium dioxide (CeO)₂) 4f orbital with underfill of electrons and lanthanide contraction, etcCharacterized by 8 coordinated metal atoms in the middle of each cube, even if reduced to CeO_2-x(0<x<0.5), the structure remains unchanged, exhibiting unique oxygen storage and release properties, and thus ceria (CeO)₂) As an important component in the denitration catalyst material. MnO_xIncluding MnO₂And Mn₂O₃Two oxidation states are rapidly converted back and forth in the denitration process to achieve the purposes of oxygen storage and oxygen release, so that MnO is adopted_xAs transition oxide, CeO_x-MnO_x/TiO₂The SCR denitration catalyst comprises essential components. Anatase TiO₂Has strong oxidizing property, more oxygen vacancies and Lewis acid sites, is NH₃、NO、O₂Provides a necessary site for adsorption of (A), and thus anatase TiO₂Has strong adsorption effect and can be used as a good load carrier in the SCR denitration catalyst.

Through search, the Chinese invention patent application publication No. CN101518718A, application date: 28/2008, a functional filter felt for purifying harmful components in flue gas is disclosed, which consists of a fiber material and a functional catalyst with catalytic desulfurization and/or denitrification reactions, wherein the active component of the functional catalyst consists of one or more of noble metals and metal oxides, the noble metals are one or more of gold, silver or platinum group metals, the platinum group metals are ruthenium, rhodium, palladium, osmium, iridium or platinum, and the metal oxides are CuO, Cu₂O、V₂O₅、CoO、Co₂O₃、MnO₂、Mn₂O₃、Mn₃O₄、Fe₂O₃、FeO、Fe₃O₄、MoO₃、WO₃、CeO₂One or more of (a). The invention mentions the preparation of a desulfurization and/or denitrification catalyst using a noble metal, but does not mention the specific amount of the noble metal in the catalyst, nor does it specifically consider the denitrification effect and anti-poisoning property of the catalyst at low temperatures.

For another example, chinese patent application publication No. CN109847745A, application date: 12.2018, 29 months and disclose 1A preparation method of a ruthenium system ultralow temperature denitration catalyst adopts sectional impregnation and roasting to prepare Ru-Ce-Mn/TiO₂A catalyst; the catalyst has extremely high NO at the ultralow temperature of 80-120 DEG C_xThe removal activity and good anti-poisoning performance. However, in this application, a cerium compound and a manganese compound are first prepared into an active component solution A, and the active component solution A is loaded on TiO by an impregnation method₂Roasting on a carrier to obtain Ce-Mn/TiO₂A catalyst; then preparing an active component solution B from the ruthenium compound, loading the active component solution B on a Ce-Mn/TiO2 catalyst by an impregnation method, and roasting to obtain Ru-Ce-Mn/TiO₂Catalyst, whereby the Ce-Mn/TiO has to be first reacted₂Prepared and then mixed in Ce-Mn/TiO₂On the basis of adding Ru, the preparation method of the catalyst is complex, and the water-sulfur resistance is low.

Disclosure of Invention

1. Technical problem to be solved by the invention

Aiming at the problems of complicated preparation steps, low water and sulfur resistance and the like of a ruthenium low-temperature denitration catalyst in the prior art, the invention provides a preparation method of a ruthenium low-temperature denitration catalyst for sintering flue gas with high water and sulfur resistance, which adopts a wet co-impregnation method and TiO₂Impregnating and loading an active component solution A prepared from a cerium compound, a manganese compound and a ruthenium compound into a carrier, and roasting to obtain RuO_x-CeO_x-MnO_x/TiO₂The catalyst is prepared by adopting one-step impregnation roasting, compared with RuO prepared in two steps_x-CeO_x-MnO_x/TiO₂The catalyst has the advantages of similar effect contrast ratio, simple process and great improvement on the water and sulfur resistance.

2. Technical scheme

In order to achieve the purpose, the technical scheme provided by the invention is as follows:

a preparation method of a ruthenium-based high-water-sulfur-resistance sintering flue gas low-temperature denitration catalyst comprises the following steps:

preparing an active component solution A from a cerium compound, a manganese compound, a ruthenium compound and deionized water;

step two,By wet co-impregnation with TiO₂Impregnating and loading the solution A in the step one for the carrier, and then roasting to obtain RuO_x-CeO_x-MnO_x/TiO₂(hereinafter referred to as RCMT) catalyst.

In the step one, the cerium compound, the manganese compound and the ruthenium compound are respectively cerium nitrate hexahydrate (Ce (NO)₃)₃·6H₂O), manganese nitrate (Mn (NO)₃)₂) And ruthenium nitrosylnitrate (N)₄O₁₀Ru), the RuO_xThe addition of the catalyst greatly improves the water and sulfur resistance of the RCMT catalyst, and makes a contribution to promoting the ultra-low temperature (60-150 ℃) denitration in the steel industry.

Further technical solution, the RuO_xThe addition amount of the CeO is 0.5-3 percent_x2-5% of MnO_x5-8% of TiO₂87-89.5 percent; in the mass ratio of the actual metal elements, Ru accounts for 0.38-2.28%, Ce accounts for 1.63-4.1%, Mn accounts for 3.16-5.06%, and Ti accounts for 52.2-53.7%. Because the addition amount of Ru is increased, the RCMT catalyst has water resistance and SO resistance₂And water + SO resistance₂The performance is gradually improved, so the addition of Ru can promote the water-sulfur resistance of the RCMT catalyst to be greatly improved.

In the step two, the wet co-impregnation method comprises the following steps:

s1, stirring the weighed active component solution A vigorously for 5 minutes at room temperature;

s2, weighing anatase TiO₂The powder was slowly added to the active ingredient solution a being vigorously stirred for 1 hour to obtain a mixture solution.

In a further technical scheme, in step S2, the obtained mixture solution is placed in a heat collection type magnetic stirrer at 60 ℃ for heating and is stirred vigorously at the same time until the mixture solution is basically evaporated to dryness, and a mixture solid product is obtained.

The further technical scheme is that the mixture solid product is dried in a drying oven at 110 ℃ for one night, then is put in a muffle furnace with room temperature and air introduced for roasting, and the RCMT catalyst is obtained after roasting is finishedThe product adopts low cerium manganese loading (10 percent) and one-step dipping roasting, compared with the low-temperature NH of the RCMT catalyst prepared by high cerium manganese loading (20 percent) and two-step dipping roasting₃SCR results are almost equal, the total active component of the prepared catalyst is about 10 percent, the active component of the prepared catalyst is reduced from the previous 20 percent to 10 percent, the production cost is greatly reduced, and NH₃The SCR effect is very good.

According to the further technical scheme, the mixture solid product is roasted in a muffle furnace, heated to any temperature of 300-550 ℃ at a heating rate of 5 ℃/min, and roasted for 3-5 hours. Compared with the RCMT catalyst prepared by two steps in the prior art, the catalyst prepared by one-step dipping and roasting has better effect, simple process, lower production cost and higher water and sulfur resistance improvement.

According to a further technical scheme, active component solution A is prepared by mixing cerium nitrate hexahydrate, a 50% manganese nitrate solution and a ruthenium nitrosyl nitrate solution serving as cerium, manganese and ruthenium sources with deionized water respectively, and Ce, Mn and Ru are directly mixed together to prepare the active component solution A, so that CeO does not need to be firstly mixed_x-MnO_x/TiO₂The Catalyst (CMT) is prepared and then loaded with Ru, thereby simplifying the process steps, and the RCMT catalyst prepared by one step is compared with the RCMT catalyst prepared by two steps in the prior art to prepare low-temperature NH₃The SCR has the advantages of almost same effect, simple working procedures and lower production cost.

3. Advantageous effects

Compared with the prior art, the technical scheme provided by the invention has the following beneficial effects:

(1) the invention relates to a preparation method of a ruthenium-based high-water-sulfur-resistance sintering flue gas low-temperature denitration catalyst, which adopts a wet co-impregnation method and TiO₂Impregnating a carrier with an active component solution A prepared from a cerium compound, a manganese compound, a ruthenium compound and deionized water, and roasting to obtain the RCMT catalyst₃Almost SCR effect, simple process, great improvement of water and sulfur resistance, and catalystThe preparation method is simple, the production cost is low, and the preparation method is suitable for industrial mass preparation;

(2) the invention relates to a preparation method of a ruthenium-based high-water-sulfur-resistance sintering flue gas low-temperature denitration catalyst, and RuO_xThe addition of the catalyst greatly improves the water and sulfur resistance of the RCMT catalyst, and contributes to promoting the ultra-low temperature (60-150 ℃) denitration in the steel industry;

(3) according to the preparation method of the ruthenium-based high-water-sulfur-resistance sintering flue gas low-temperature denitration catalyst, the RCMT catalyst product is obtained after roasting, the total active component is about 10%, and the active component is reduced to 10% from the previous 20%, so that the production cost is greatly reduced, and the NH content at low temperature is reduced₃The SCR effect is good;

(4) the invention relates to a preparation method of a ruthenium-based high-water-sulfur-resistance sintering flue gas low-temperature denitration catalyst, which respectively uses cerium nitrate hexahydrate (Ce (NO)₃)₃·6H₂O), 50% manganese nitrate solution (Mn (NO)₃)₂) And ruthenium nitrosylnitrate (N)₄O₁₀Ru) is used as a source of cerium, manganese and ruthenium and deionized water to prepare an active component solution A so as to directly mix Ce, Mn and Ru with the deionized water to prepare the active component solution A, so that a CMT catalyst does not need to be prepared first and then loaded with Ru, and the process steps are simplified; compared with the RCMT catalyst prepared by two steps, the RCMT catalyst prepared by one step has the advantages of almost good effect, simple process and lower production cost.

Drawings

FIG. 1 shows CeO_x-MnO_x/TiO₂And RuO_x-CeO_x-MnO_x/TiO₂NH of catalyst₃-SCR activity comparison graph;

FIG. 2 shows CeO_x-MnO_x/TiO₂And RuO_x-CeO_x-MnO_x/TiO₂Comparative SCR activity of catalyst in aqueous atmosphere;

FIG. 3 shows CeO_x-MnO_x/TiO₂And RuO_x-CeO_x-MnO_x/TiO₂Catalyst in presence of SO₂Comparative plot of SCR activity in atmosphere;

FIG. 4 shows CeO_x-MnO_x/TiO₂And RuO_x-CeO_x-MnO_x/TiO₂Catalyst in water + SO₂SCR activity in atmosphere is plotted against time.

Detailed Description

For a further understanding of the invention, reference should be made to the following detailed description taken in conjunction with the accompanying drawings.

Example 1

The preparation method of the ruthenium-based high-water-sulfur-resistance sintering flue gas low-temperature denitration catalyst of the embodiment, as shown in fig. 3, comprises the following steps:

preparing an active component solution A from a cerium compound, a manganese compound, a ruthenium compound and deionized water;

step two, adopting a wet co-impregnation method to prepare TiO₂And (3) impregnating the carrier with the solution A in the first step, and roasting to obtain the RCMT catalyst.

In this embodiment, the RCMT catalyst comprises the following components in percentage by mass: CeO (CeO)₂2-5% of MnO₂5-8% of RuO₂3% of TiO₂The content is 87%. The actual metal element mass ratio is as follows: ce accounts for 1.63-4.1%, Mn accounts for 3.16-5.06%, Ru accounts for 2.28%, and Ti accounts for 52.2%. The preparation method adopts one-step dipping roasting, and simultaneously adopts low cerium and manganese loading (10%) and one-step dipping roasting, compared with the low-temperature NH of the RCMT catalyst prepared by high cerium and manganese loading (20%) and two-step dipping roasting₃The SCR effect is almost the same, the working procedure is simple, and the water and sulfur resistance is greatly improved; meanwhile, the catalyst is simple in preparation method, low in production cost and suitable for industrial mass preparation.

Example 2

The basic structure of the preparation method of the ruthenium-based high-water-sulfur-resistance sintering flue gas low-temperature denitration catalyst is the same as that of the embodiment 1, and the difference and the improvement are as follows: in the second step, the wet co-impregnation method comprises the following steps:

s1, stirring the weighed active component solution A vigorously for 5 minutes at room temperature;

s2, mixingWeighed anatase TiO₂The powder was slowly added to the active solution being vigorously stirred for 1 hour to obtain a mixture solution.

In the further technical scheme, in S1, cerous nitrate hexahydrate (Ce (NO) is respectively used₃)₃·6H₂O), 50% manganese nitrate solution (Mn (NO)₃)₂) And ruthenium nitrosylnitrate (N)₄O₁₀Ru) as a source of cerium, manganese and ruthenium to prepare an active component solution A to directly mix Ce, Mn and Ru together, thereby eliminating the need to prepare a CMT catalyst first and then load Ru, thereby simplifying the process steps, and the RCMT catalyst prepared in one step has a lower temperature NH than the RCMT catalyst prepared in two steps₃The SCR effect is almost the same, and the working procedure is simple.

And S2, heating the obtained mixture solution in a magnetic stirrer with a heat collection function at 60 ℃ and stirring vigorously until the mixture solution is basically evaporated to dryness to obtain a mixture solid product. Drying the mixture solid product in a drying oven at 110 ℃ for one night, then placing the mixture solid product in a muffle furnace which is at room temperature and is filled with air, heating the mixture solid product to 300-550 ℃ at the heating rate of 5 ℃/min, roasting the mixture solid product for 3-5 hours, and obtaining the RCMT catalyst product after roasting, wherein the total active component of the prepared catalyst is about 10 percent, and the active component of the prepared catalyst is reduced from 20 percent to 10 percent, so that the production cost is greatly reduced, and the NH content at low temperature is low₃The SCR effect is good; compared with the RCMT catalyst prepared by two steps, the method has the same effect, simple process and higher water and sulfur resistance improvement by adopting one-step dipping roasting. The CMT and RCMT catalysts were tested in comparative validation as follows:

as shown in FIG. 1, CeO_x-MnO_x/TiO₂And RuO_x-CeO_x-MnO_x/TiO₂Catalyst in clean flue gas (without steam and SO)₂) The medium denitration activity is almost the same.

As can be seen from FIG. 2, the RuO-containing_xThe catalyst has good steam resistance, the NO conversion rate of 10 percent of steam is about 50 percent and is improved by about 10 percent compared with a CMT catalyst, the steam is stopped after 4 hours, and the NO conversion rate can be100% recovery, whereas the CMT catalyst can only recover to 89%.

As can be seen from FIG. 3, the sulfur resistance of the Ru-containing catalyst was improved by passing 110ppm SO₂Then, the NO conversion rate is reduced to about 35 percent, is improved by 5 to 11 percent compared with a CMT catalyst, and the SO is stopped and introduced after 8 hours₂The NO conversion rate is continuously decreased.

As can be seen from FIG. 4, the water and sulfur resistance of the Ru-containing catalyst is improved, and 110ppm SO is introduced₂And 10% water vapor, the NO conversion is reduced to 45%, which is about 7-10% higher than the CMT catalyst. After stopping the introduction of sulfur, the NO conversion rate of the ruthenium-containing catalyst is recovered to about 55%, while the NO conversion rate of the CMT catalyst can not be recovered and is improved by about 25% compared with the CMT catalyst.

In conclusion, the addition of Ru hardly improves the low-temperature denitration activity of the CMT catalyst, but obviously improves the water-resistant and sulfur poisoning-resistant performance of the CMT catalyst. H resistance of RCMT catalyst at 130 deg.C₂O_(g)、SO₂、H₂O_(g)+SO₂The poisoning performance is 10%, 5-11% and 7-30% higher than that of CMT catalyst. The reason for this may be with RuO_xIncreased content of RuO_xSacrificial sites have been created to protect portions of the original active site.

The present invention and its embodiments have been described above schematically, without limitation, and what is shown in the drawings is only one of the embodiments of the present invention, and the actual structure is not limited thereto. Therefore, if the person skilled in the art receives the teaching, without departing from the spirit of the invention, the person skilled in the art shall not inventively design the similar structural modes and embodiments to the technical solution, but shall fall within the scope of the invention.