阅读说明：本技术 可实现同步脱硝脱VOCs和CO的再生催化剂及其制备方法 (Regenerated catalyst capable of realizing synchronous denitration and VOCs and CO removal and preparation method thereof ) 是由 何川 张发捷 孔凡海 王乐乐 鲍强 姚燕 李乐田 马云龙 卞子君 王凯 吴国勋 于 2020-11-18 设计创作，主要内容包括：本发明公开了一种可实现同步脱硝脱VOCs和CO的再生催化剂及其制备方法,该方法包括如下步骤：将失活催化剂置于清水中,曝气清洗；然后将其浸入NaOH溶液中,曝气鼓泡清洗；再将其浸入H-2SO-4溶液中超声清洗；最后将其置于清水中曝气清洗；制备Ce-Co活性体系改性负载液；将经过深度清洗后的失活催化剂缓慢置于Ce-Co活性体系改性负载液中,常温条件下负载后再依次进行烘干、煅烧,制得具有可实现同步脱硝脱VOCs和CO功能的再生催化剂。制得的再生催化剂在原有活性成分的基础上增加了Ce-Co活性体系,不仅提高了脱硝能力,同时具有良好的脱VOCs和CO的能力,并且其中的原有杂质被有效去除,其催化品质提高。(The invention discloses a regenerated catalyst capable of realizing synchronous denitration and VOCs and CO removal and a preparation method thereof, wherein the method comprises the following steps: putting the deactivated catalyst into clear water, and carrying out aeration cleaning; then immersing the membrane in NaOH solution, and carrying out aeration and bubbling cleaning; then immersing it in H 2 SO 4 Ultrasonic cleaning in solution; finally, placing the mixture into clean water for aeration cleaning; preparing a Ce-Co active system modified negative carrier liquid; and slowly placing the deeply cleaned deactivated catalyst in a Ce-Co active system modified negative carrier liquid, loading at normal temperature, and then sequentially drying and calcining to prepare the regenerated catalyst with the functions of synchronously denitrifying and removing VOCs and CO. The prepared regenerated catalyst is added with a Ce-Co active system on the basis of the original active ingredients, so that the denitration capacity is improved, the denitration catalyst has good VOCs and CO removal capacity, the original impurities are effectively removed, and the catalytic quality is improved.)

1. A preparation method of a regenerated catalyst capable of realizing synchronous denitration and VOCs and CO removal is characterized by comprising the following steps:

(1) acid-base deep cleaning

Placing the deactivated catalyst in clear water, and carrying out aeration cleaning for 20-60 min at normal temperature; then taking out the deactivated catalyst from clear water, immersing the deactivated catalyst into NaOH solution with the concentration of 0.5-2.0 wt%, and carrying out aeration bubble cleaning for 20-60 min at the temperature of 40 ℃; taking out the catalyst, and then soaking the deactivated catalyst into H with the concentration of 0.5-2.0 wt%₂SO₄Cleaning in the solution for 20-60 min, wherein ultrasonic treatment is assisted in the cleaning process; finally, taking out the deactivated catalyst after the acid treatment, putting the deactivated catalyst into clear water again, and carrying out aeration cleaning for 30-40 min at normal temperature;

(2) preparation of Ce-Co active system modified negative carrier liquid

Adding oxalic acid with the concentration of 2.0 wt% into deionized water, continuously stirring at the temperature of 45-50 ℃, adding cerium nitrate while stirring, continuously stirring for 2 hours, adding cobalt nitrate, and continuously stirring for 5 hours to prepare a Ce-Co active system modified negative carrier liquid;

(3) preparation of Ce-Co active system modified load regeneration catalyst

Slowly placing the deeply cleaned deactivated catalyst into the Ce-Co active system modified negative carrier liquid prepared in the step (2), and loading for 1-10 min at normal temperature; and then drying and calcining are carried out in sequence to prepare the regenerated catalyst with the functions of synchronous denitration and VOCs and CO removal.

2. The method according to claim 1, wherein the active substance in the deactivated catalyst is V₂O₅。

3. The method for preparing the regenerated catalyst capable of synchronously removing the NOx, the VOCs and the CO according to claim 2, wherein the original active substance V in the catalyst is deactivated after the acid-base deep cleaning treatment in the step (1)₂O₅The content of (A) is reduced to below 0.2%.

4. The preparation method of the regenerated catalyst capable of synchronously removing the NOx and the VOCs and the CO according to claim 1, wherein in the Ce-Co active system modified negative carrier liquid obtained in the step (2), the content of cerium nitrate is 1.5-5.0 wt%, and the content of cobalt nitrate is 1.0-5.0 wt%.

5. The preparation method of the regenerated catalyst capable of realizing synchronous denitration and VOCs and CO removal according to claim 1, wherein the drying temperature in the step (3) is 85-120 ℃, and the drying time is 10-15 h; the calcining temperature in the step (3) is 400-600 ℃, and the calcining time is 5-8 h.

6. A regenerated catalyst capable of realizing synchronous denitration and VOCs and CO removal prepared by the preparation method of any one of claims 1 to 5.

7. The device of claim 6, wherein the device can realize synchronous denitration and denitrationThe regenerated catalyst of VOCs and CO is characterized by containing 1.0-3.5 wt% of CeO₂0.5 to 3.5 wt% of Co₂O₃4.0 to 8.0 wt% of WO₃86.0 to 92.0 wt% of TiO₂。

Technical Field

The invention belongs to the technical field of environmental catalysis and waste gas treatment, and particularly relates to a regenerated catalyst capable of realizing synchronous denitration and VOCs and CO removal and a preparation method thereof.

Background

At present, the atmospheric pollution in China has become a main environmental pollution problem. The production of industries such as waste incineration, coking, printing, steel and the like discharges a large amount of pollutants such as nitrogen oxides (NOx), Volatile Organic Compounds (VOCs), carbon monoxide (CO) and the like, and the atmospheric pollutants can cause serious harm to the natural environment and human health. NOx is an important pollutant causing acid rain, haze and photochemical pollution, and China has long provided strict control standards for the emission of the NOx. VOCs are important precursor substances of atmospheric composite pollutants, VOCs discharged into the atmosphere are extremely easy to form organic fine particle composite pollutants, and are one of main causes of haze, and the strict control of the discharge of VOCs is an important measure for controlling haze from the source. CO is one of main gaseous pollutants generated by incomplete combustion of fossil fuels, wastes and the like, exists in the industrial production process, and poses a threat to human health while endangering the environment, so that effective treatment of CO emission is essential.

The most effective means of NOx control at present is the Selective Catalyst Reduction (SCR) technique, which utilizes a catalyst on NH₃Reduction of NOx to harmless N₂. China has a large number of SCR catalysts applied to facilities such as power plants, industrial boilers and the like. The deactivated SCR catalyst that has been used requires the use of regeneration techniques to form a regenerated catalyst;the regeneration technology needs to endow the regenerated catalyst with the function of removing VOCs and CO besides the function of recovering the denitration of the regenerated catalyst. Therefore, the research on the preparation method of the regenerated catalyst capable of synchronously denitrifying and removing VOCs and CO is of great significance.

Disclosure of Invention

In order to solve the technical problems, the invention aims to provide a regenerated catalyst capable of realizing synchronous denitration and VOCs and CO removal and a preparation method thereof; the regenerated catalyst obtained by the method is added with a Ce-Co active system on the basis of the original active ingredients of the deactivated catalyst, so that the denitration capability is improved, the denitration catalyst has good capability of removing VOCs and CO, the original impurities in the denitration catalyst are effectively removed, and the catalytic quality of the denitration catalyst is improved.

In order to achieve the technical purpose and achieve the technical effect, the invention is realized by the following technical scheme:

a preparation method of a regenerated catalyst capable of realizing synchronous denitration and VOCs and CO removal comprises the following steps:

(1) acid-base deep cleaning

Placing the deactivated catalyst in clear water, and carrying out aeration cleaning for 20-60 min at normal temperature; then taking out the deactivated catalyst from clear water, immersing the deactivated catalyst into NaOH solution with the concentration of 0.5-2.0 wt%, and carrying out aeration bubble cleaning for 20-60 min at the temperature of 40 ℃; taking out the catalyst, and then soaking the deactivated catalyst into H with the concentration of 0.5-2.0 wt%₂SO₄Cleaning in the solution for 20-60 min, wherein ultrasonic treatment is assisted in the cleaning process; finally, taking out the deactivated catalyst after the acid treatment, putting the deactivated catalyst into clear water again, and carrying out aeration cleaning for 30-40 min at normal temperature;

(2) preparation of Ce-Co active system modified negative carrier liquid

Adding oxalic acid with the concentration of 2.0 wt% into deionized water, continuously stirring at the temperature of 45-50 ℃, adding cerium nitrate while stirring, continuously stirring for 2 hours, adding cobalt nitrate, and continuously stirring for 5 hours to prepare a Ce-Co active system modified negative carrier liquid;

(3) preparation of Ce-Co active system modified load regeneration catalyst

Slowly placing the deeply cleaned deactivated catalyst into the Ce-Co active system modified negative carrier liquid prepared in the step (2), and loading for 1-10 min at normal temperature; and then drying and calcining are carried out in sequence to prepare the regenerated catalyst with the functions of synchronous denitration and VOCs and CO removal.

Further, the original active substance in the deactivated catalyst is V₂O₅。

Further, after the acid-base deep cleaning treatment in the step (1), the original active substance V in the catalyst is deactivated₂O₅The content of (A) is reduced to below 0.2%.

Further, in the Ce-Co active system modified negative carrier liquid obtained in the step (2), the content of cerium nitrate is 1.5-5.0 wt%, and the content of cobalt nitrate is 1.0-5.0 wt%.

Further, the drying temperature in the step (3) is 85-120 ℃, and the drying time is 10-15 h; the calcining temperature in the step (3) is 400-600 ℃, and the calcining time is 5-8 h.

The invention also provides the regenerated catalyst capable of realizing synchronous denitration and VOCs and CO removal prepared by the preparation method.

Further, the regenerated catalyst contains 1.0-3.5 wt% of CeO₂0.5 to 3.5 wt% of Co₂O₃4.0 to 8.0 wt% of WO₃86.0 to 92.0 wt% of TiO₂。

The invention has the beneficial effects that:

(1) according to the invention, through the coordination of clear water aeration cleaning, alkali solution aeration cleaning, acid solution ultrasonic cleaning and clear water secondary aeration cleaning, impurities such as Si, Al, Fe and the like on the surface of the deactivated catalyst are effectively removed, so that the quality of the finally prepared regenerated catalyst is improved; and after the whole acid-base deep cleaning, the original active component V is added₂O₅The content of the active ingredient is reduced to be less than 0.2 percent, so that the content of the original active ingredient is controllable, and a new active ingredient is convenient to add, so that the original active ingredient and the added active ingredient form better matching.

(2) The regenerated catalyst prepared by the method is added with the Ce-Co active component, and can effectively improveThe catalyst has catalytic combustion capability on VOCs and CO, and converts the VOCs and CO into harmless H₂O and CO₂Simultaneously binding original active substance V₂O₅The purposes of synchronously denitrating and removing VOCs and CO are achieved, so that the waste gas treatment cost is reduced, and the treatment efficiency is improved.

Drawings

Fig. 1 is a schematic flow chart of a preparation method of a regenerated catalyst capable of synchronously removing nox and VOCs and CO provided in embodiments 1 to 3 of the present invention.

Detailed Description

The technical solutions in the present invention will be described clearly and completely with reference to specific embodiments, and it should be understood that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

Example 1

Deactivated catalyst sample: the size is as follows: 150mm × 150mm × 1100mm, the number of holes being: and (4) 18 holes.

As shown in fig. 1, the preparation method of the regenerated catalyst capable of synchronously denitrating and removing VOCs and CO includes the following steps:

acid-base deep cleaning: placing the sample in clear water, and aerating and cleaning for 20min at normal temperature; then taking out the deactivated catalyst from the clear water, immersing the deactivated catalyst into NaOH solution with the concentration of 0.8 wt%, and carrying out aeration cleaning for 30min at the temperature of 40 ℃; after removal, the deactivated catalyst was again immersed in H at a concentration of 0.5 wt%₂SO₄Cleaning in the solution for 30min, wherein ultrasonic treatment is assisted in the cleaning process; and finally, taking out the deactivated catalyst after the acid treatment, and placing the deactivated catalyst in clean water again to carry out aeration cleaning for 30min at the normal temperature.

Preparation of the Ce-Co active system modified negative carrier liquid: adding oxalic acid with the concentration of 2.0 wt% into deionized water; continuously stirring at 45 ℃, simultaneously adding cerium nitrate, continuously stirring at 45 ℃ for 2h, adding cobalt nitrate, and continuously stirring for 5h to obtain the Ce-Co active system modified negative carrier liquid. The content of cerium nitrate in the obtained negative carrier liquid is 1.5 wt%, and the content of cobalt nitrate is 1.2 wt%.

Preparation of the Ce-Co active system modified load regeneration catalyst: slowly placing the deeply cleaned deactivated catalyst in the negative carrier liquid, and carrying for 2min at normal temperature; then drying the catalyst for 12h at the temperature of 90 ℃, and then calcining the catalyst for 5h at the temperature of 500 ℃ to obtain the Ce-Co active system modified supported regenerated catalyst;

the regenerated catalyst sample with the synchronous denitration and VOCs and CO removal functions comprises the following main components: 1.1 wt% of CeO₂0.8 wt% of Co₂O₃5.4 wt% of WO₃90.3 wt% TiO₂(ii) a The regenerated catalyst also contains a small amount of V₂O₅And other ingredients.

Example 2

Deactivated catalyst sample: the size is as follows: 150mm × 150mm × 800mm, the number of holes being: and (4) 18 holes.

Acid-base deep cleaning: placing the sample in clear water, and aerating and cleaning for 60min at normal temperature; then taking out the deactivated catalyst from the clear water, immersing the deactivated catalyst into NaOH solution with the concentration of 1.7 wt%, and carrying out aeration cleaning for 40min at the temperature of 40 ℃; after removal, the deactivated catalyst was again immersed in H at a concentration of 1.8 wt%₂SO₄Cleaning in the solution for 55min, wherein ultrasonic treatment is assisted in the cleaning process; and finally, taking out the deactivated catalyst after the acid treatment, and placing the deactivated catalyst in clean water again to carry out aeration cleaning for 30min at the normal temperature.

Preparation of the Ce-Co active system modified negative carrier liquid: adding oxalic acid with the concentration of 2.0 wt% into deionized water; continuously stirring at 45 ℃, simultaneously adding cerium nitrate, continuously stirring at 45 ℃ for 2h, adding cobalt nitrate, and continuously stirring for 5h to obtain the Ce-Co active system modified negative carrier liquid. The content of cerium nitrate and cobalt nitrate in the obtained negative carrier liquid is 4.9 wt% and 4.7 wt%.

Preparation of the Ce-Co active system modified load regeneration catalyst: slowly placing the deeply cleaned deactivated catalyst in the negative carrier liquid, and carrying for 8min at normal temperature; then drying the catalyst for 12h at the temperature of 110 ℃, and then calcining the catalyst for 5h at the temperature of 600 ℃ to obtain the Ce-Co active system modified supported regenerated catalyst;

the regenerated catalyst sample with the synchronous denitration and VOCs and CO removal functions comprises the following main components: 3.4 wt% of CeO₂3.2 wt% of Co₂O₃4.0% by weight of WO₃87.0% by weight of TiO₂(ii) a The regenerated catalyst also contains a small amount of V₂O₅And other ingredients.

Example 3

Deactivated catalyst sample: the size is as follows: 150mm × 150mm × 975mm, the number of holes being: 21 holes.

Acid-base deep cleaning: placing the sample in clear water, and aerating and cleaning for 40min at normal temperature; then taking out the deactivated catalyst from the clear water, immersing the deactivated catalyst into NaOH solution with the concentration of 1.3 wt%, and carrying out aeration cleaning for 50min at the temperature of 40 ℃; after removal, the deactivated catalyst was again immersed in H at a concentration of 1.0 wt%₂SO₄Cleaning in the solution for 40min, wherein ultrasonic treatment is assisted in the cleaning process; and finally, taking out the deactivated catalyst after the acid treatment, and placing the deactivated catalyst in clean water again to carry out aeration cleaning for 30min at the normal temperature.

Preparation of the Ce-Co active system modified negative carrier liquid: adding oxalic acid with the concentration of 2.0 wt% into deionized water; continuously stirring at 45 ℃, simultaneously adding cerium nitrate, continuously stirring at 45 ℃ for 2h, adding cobalt nitrate, and continuously stirring for 5h to obtain the Ce-Co active system modified negative carrier liquid. The content of cerium nitrate and cobalt nitrate in the obtained negative carrier liquid is 2.8 wt% and 2.0 wt%.

Preparation of the Ce-Co active system modified load regeneration catalyst: slowly placing the deeply cleaned deactivated catalyst in the negative carrier liquid, and carrying for 5min at normal temperature; then drying for 12h at 100 ℃, and then calcining for 5h at 400 ℃ to obtain the Ce-Co active system modified supported regenerated catalyst;

the regenerated catalyst sample with the synchronous denitration and VOCs and CO removal functions comprises the following main components: 2.3 wt.% of CeO₂1.5 wt% of Co₂O₃5.3 wt% of WO₃89.7 wt% of TiO₂(ii) a The regenerated catalyst also contains a small amount of V₂O₅And other ingredients.

The performance of the synchronous denitration and CO removal catalyst prepared in the embodiment 1-3 of the invention is tested in a fixed bed reactor: crushing and grinding each sample, sieving the crushed and ground sample by a 40-60-mesh sieve, and placing 2ml of prepared granular sample in a constant-temperature section of a fixed bed reactor; the used simulated flue gas consists of 500ppm NO and 500ppm NH₃1000ppm xylene (VOCs), 900ppm CO, 20ppm SO₂、9％O₂、13％H₂O and the balance N₂The flow is controlled by a mass flowmeter. Enabling components of the flue gas to enter a self-made fixed bed reactor through a mixer; the reactor is made of a quartz tube with the diameter of 8mm, and the outside of the reactor is heat-tracing and heat-preserving by a heat tracing band. The test sample is placed in a constant temperature section of the reactor, and the temperature of the test smoke is 230 ℃. And the flue gas at the outlet of the reactor is treated by an activated carbon tail gas treatment system and then is discharged.

Testing the concentration of NO in the flue gas at the inlet and the outlet of the reactor, and calculating the denitration efficiency of the sample by a formula (1);

ηNO＝(NO_in-NO_out)/NO_in×100 (1)

in the formula: eta NO is the denitration efficiency of the sample; NO_inIs the concentration of the reactor inlet flue gas NO; NO_outIs the concentration of the flue gas NO at the outlet of the reactor.

Calculating the catalytic combustion efficiency of VOCs of the sample according to the formula (2);

ηVOC＝(VOC_in-VOC_out)/VOC_in×100 (2)

in the formula: eta VOC is the denitration efficiency of the sample; VOC_inIs the concentration of VOC in the reactor inlet flue gas; VOC_outIs the concentration of VOC in the flue gas at the outlet of the reactor.

The CO catalytic combustion efficiency of the sample was calculated according to equation (3).

ηCO＝(CO_in-CO_out)/CO_in×100 (3)

In the formula: eta CO is the denitration efficiency of the sample; CO 2_inIs the concentration of the flue gas CO at the inlet of the reactor; CO 2_outIs the concentration of CO in the flue gas at the outlet of the reactor.

The denitration, VOCs removal, and CO removal efficiencies of the regenerated catalyst samples of examples 1-3 are shown in Table 1.

TABLE 1 DeNOx, VOCs, and CO removal efficiencies of the regenerated catalyst samples of examples 1-3

As can be seen from Table 1, after the deactivated SCR catalyst is treated by the method of the present invention, the denitration performance of the catalyst can be effectively recovered, and the combustion effect of the catalyst on VOCs and CO can be significantly increased.

The above description is only an embodiment of the present invention, and not intended to limit the scope of the present invention, and all modifications of equivalent structures and equivalent processes performed by the present specification and drawings, or directly or indirectly applied to other related technical fields, are included in the scope of the present invention.