TWI648102B - Method of preparing catalyst for treating tail gas containing nitrogen oxide and method of treating tail gas containing nitrogen oxide - Google Patents

Abstract

The invention provides a preparation method for treating a nitrogen-containing oxide tail gas and a method for treating a nitrogen-containing oxide tail gas, wherein the preparation method is used for preparing a catalyst, and the catalyst can be further based on one by using carbon monoxide. Selective catalyst reduction to treat a nitrogen-containing oxide tail gas, the method comprising the steps of: providing a carrier; and providing a precursor comprising copper, ruthenium, iron, and cobalt, and dissolving the precursor; and dissolving The precursor is then applied to the carrier and a processing step is performed to form a catalyst.

Description

Method for preparing catalyst for treating nitrogen-containing oxide tail gas and method for treating nitrogen-containing oxide tail gas

The present invention relates to a method for preparing a catalyst for treating nitrogen-containing oxide tail gas and a method for treating nitrogen-containing oxide tail gas, and more particularly to a method for treating nitrogen-containing oxide tail gas by applying a CO-SCR system A method for preparing a medium and a method for treating a nitrogen-containing oxide tail gas.

Nitrogen oxides (NO _x ) are important air pollutants that are difficult to avoid in combustion processes. Nitrogen oxides not only cause negative impacts on the global environment, but also damage the respiratory system of the human lungs. The existing method for the removal of nitrogen oxides in the industry mainly uses Selective Catalytic Reduction (SCR), which adds an additional reducing agent such as ammonia (NH ₃ ) to the flue gas and transmits vanadium. The tungsten-titanium (VW/TiO ₂ ) catalyst catalyzes the reduction of nitrogen oxides to nitrogen (N ₂ ) and water (H ₂ O).

For example, previous scholars published in the journal Journal of Today, Vol. 184, pp. 227-236 (2012), entitled "Rare Earth Vanadium with TiO ₂ -WO ₃ /SiO ₂ as Carrier to Improve NH ₃ - stability at High temperature "of the SCR catalyst using _{V 2 O 5 / TiO 2 -WO} 3 -SiO 2, the NO concentration is 200ppm, NH ₃ and O ₂ concentration of 200ppm concentration of 2% of the conditions, the removal of NO The efficiency can reach 90% at 325 °C; and the previous scholars published in the application of catalytic reaction B: Environmental Journal, Vol. 142, pp. 705-717 (2013), entitled "Addition of Sb-V _{2 to} cerium oxide O ₅ /TiO ₂ catalyst for low temperature NH ₃ -SCR: physicochemical properties and catalytic activity" using Sb-V ₂ O ₅ /TiO ₂ at a concentration of 800 ppm, a concentration of NH ₃ of 800 ppm, and an O ₂ concentration of 3 The removal efficiency of NO can reach 95% under the condition of % and operating temperature of 250 °C.

In general, the typical selective catalyst reduction system has been developed for many years and the technology is quite mature, but there are still several shortcomings to be overcome: (1) Temperature of selective catalyst reduction system operation It needs to be controlled at 250 °C to 400 °C; (2) If ammonia (NH ₃ ) is improperly controlled, there will be leakage and then discharge to the environment to cause secondary pollution; (3) Conventional selective catalyst reduction catalyst VW/TiO ₂ It may be affected by moisture (H ₂ O _(g) ) to reduce its activity, because the presence of moisture will compete with the reducing agent (NH ₃ ) on the catalyst surface; (4) NH ₃ -SCR system It is still active when the operating temperature is less than (or equal to) 300 ° C, but if the gas stream contains sulfide (S, SO ₂ ), it is easy to form NH ₄ NO ₃ , (NH ₄ ) ₂ SO ₄ and NH on the catalyst surface. _{4 by} -products such as HSO ₄ , and such by-products will block the catalyst surface, causing the SCR catalyst to lose activity. For example, previous scholars published in the Progress of Natural Science: International Journal of Materials, Vol. 25, pp. 342-352 (2013), entitled "SCR Activity at Low Temperatures with Cerium Modified V ₂ O ₅ -WO ₃ /TiO ₂ Catalysts The study of the mechanism of deactivation of SO ₂ and V ₂ O ₅ -WO ₃ /TiO ₂ was used to test the sulfur resistance characteristics in the NH ₃ -SCR system. The results show that V ₂ O ₅ -WO ₃ /TiO ₂ is contained at 200 ° C and contains 60 ppm. Under the condition of sulfur dioxide, the conversion efficiency of NO is reduced from 90% to 30%. It is analyzed that the cause of catalyst deactivation is caused by the reaction of NH ₃ and SO ₂ (NH ₄ ) ₂ SO ₄ occupying the catalyst pores, such as To overcome the effects of sulfur and moisture, the traditional SCR catalyst must be operated at a temperature greater than (or equal to) 300 ° C to avoid deactivation effects, but the medium and high temperature conditions still have energy consumption problems (300 to 400 °C).

Therefore, the conventional study utilizes carbon monoxide (CO) as a reducing agent to carry out the SCR reaction in an attempt to improve the performance and shortcomings of the conventional NH ₃ -SCR system, which is also called CO-SCR, which is directly used in flue gas. presence of carbon monoxide (CO) as a reductant, CO and NO _x to be removed at the same time, the advantages of the CO-SCR systems it is not necessary to add additionally a reducing agent (NH _3), known techniques, for example: Journal of catalysis published in previous researchers, 41 Vol., pp. 192-195 (1976), entitled "Catalytic NO-CO Reaction in the Presence of Excess O ₂ by Ir (Ir)". CO-Use of 0.1% Ir/Al ₂ O ₃ as Catalyst SCR test; and scholars previously published in chemical Letters, Vol. 29, pp. 146-147 (2000), titled "catalytic activity for NO-CO reaction of iridium (Ir) and SO ₂ in the presence of excess oxygen" of The study used 0.02% iridium (Ir) to carry on the sorghum rock for CO-SCR reaction, and its NO conversion efficiency reached 95%. In terms of water vapor resistance and sulfur resistance characteristics of CO-SCR systems, known techniques are, for example, published in the Journal of Catalysis, Vol. 229, pp. 197-205 (2005), entitled "Under Oxygen-Enriched Conditions" Reduction of NO by NO, SO ₂ promotes the activity of Ir/SiO ₂ "; and previous studies published in Chemical Letters, Vol. 29, pp. 146-147 (2000), entitled "In the presence of SO ₂ and excess oxygen The ruthenium (Ir) catalytic activity for the reaction of NO-CO. In terms of the influence of moisture, known techniques are, for example, a prior scholar published in Chemical Letters, Vol. 273, pp. 39-49 (2010), entitled "Iron/WO ₃ /SiO ₂ Catalyzed CO Selective Catalysis The study on the role of promoting the promotion of H ₂ O in NO indicates that the catalyst based on iridium (Ir) is beneficial to the water gas shift reaction (WGS) and then to hydrogen in the CO-SCR system containing H ₂ O(g). Increase NO conversion rate. Table 1 below shows the advantages and disadvantages of NH ₃ -SCR and CO-SCR in known studies.

Through the above-described known techniques understood CO-SCR NO _x removal system of great potential, but the catalyst is applied to the CO-SCR system still noble metal based materials, e.g., iridium (Ir) based catalyst. Although the catalyst of the precious metal material can exhibit high activity, if it is applied to the real field, it still has a heavy burden on the preparation cost of the catalyst. The comparison in Table 1, CO-SCR systems can be found in the removal of NO _x operation selection more flexible, in terms of practical terms, CO-SCR system than NH ₃ -SCR system more potential, due to the combustion exhaust gas usually contains a certain amount of CO, the reducing agent may be added without additional reducing agent and CO and NO _x can be removed simultaneously. Table 2 below shows the application of different precious metal catalysts in CO-SCR related research in the known technology.

However, the above-mentioned existing CO-SCR system still has the following problems in practical use, for example, the operating temperature is still high ( 300 ° C) and need to additionally warm the exhaust gas and the choice of catalyst is mostly based on precious metal catalyst (Ir).

Therefore, it is necessary to provide a preparation method for treating a nitrogen-containing oxide tail gas and a method for treating a nitrogen-containing oxide tail gas to solve the problems of the conventional technology.

The main object of the present invention is to provide a preparation method for treating a nitrogen-containing oxide tail gas and a method for treating a nitrogen-containing oxide tail gas, which utilizes carbon monoxide to treat a nitrogen-containing oxidation based on a selective catalyst reduction method. exhaust gas composition, in order to remove NO _x, and thus improve air quality and comply with regulatory standards.

A secondary object of the present invention is to provide a method for preparing a catalyst for treating nitrogen-containing oxide tail gas and a method for treating nitrogen-containing oxide tail gas, which utilizes a catalyst containing copper, barium, iron and cobalt for use. Carbon monoxide is based on a selective catalyst reduction process to treat a nitrogen-containing oxide tail gas, thereby allowing the tail gas to be treated at a lower temperature without additional energy consumption to raise the tail gas temperature.

To achieve the above object, the present invention provides a process for preparing a catalyst for treating nitrogen-containing oxide tail gas, which is used to prepare a catalyst for treating a nitrogen-containing oxide based on a selective catalyst reduction method by using carbon monoxide. Exhaust gas, the preparation method comprising the steps of: providing a carrier; and providing a precursor containing copper, ruthenium, iron and cobalt, and dissolving the precursor; and applying the dissolved precursor to the carrier, and performing one Processing steps to form a catalyst.

In an embodiment of the invention, the precursor containing copper, ruthenium, iron and cobalt is present as a metal nitrate salt.

In one embodiment of the invention, the weight ratio of the active phase of one of the precursors of copper, bismuth, iron and cobalt is from 1:1:1:1 to 1:2.3:1:1.

In an embodiment of the invention, wherein the carrier is titanium dioxide.

In an embodiment of the invention, the processing step comprises the steps of: heating the precursor added to the carrier to 80 ° C and stirring until the sample is in a paste to form a catalyst precursor; the catalyst precursor The object is placed in an oven and dried at 110 ° C for 24 hours; the dried catalyst precursor is taken out and placed in a high temperature forging furnace, heated at a heating rate of 5 ° C per minute, and continued at 400 ° C Calcination for 4 hours to form a calcining catalyst; and grinding the calcined catalyst to form the catalyst.

In another embodiment of the present invention, there is provided a method of treating a nitrogen-containing oxide tail gas by a selective catalyst reduction method, comprising the steps of: providing an off-gas comprising carbon monoxide and at least one nitrogen oxide; The exhaust gas is passed through a catalyst containing copper, ruthenium, iron and cobalt, and the tail gas utilizes carbon monoxide as a reducing agent and is catalyzed by the catalyst to carry out a denitration reaction.

In an embodiment of the invention, one of the carbon oxides contained in the exhaust gas is generated by incomplete combustion of the exhaust gas.

In an embodiment of the invention, the weight ratio of one of the copper, ruthenium, iron and cobalt active phases of the catalyst is 1:1:1:1 to 1:2.3:1:1.

In an embodiment of the invention, one of the carriers is titanium dioxide.

In an embodiment of the invention, the denitration reaction of the catalyst has an operating temperature of from 150 ° C to 250 ° C.

S11~S13‧‧‧Steps

S131~S135‧‧‧Steps

Fig. 1 is a flow chart showing a method of preparing a catalyst for treating nitrogen-containing oxide tail gas according to a first embodiment of the present invention.

Fig. 2 is a flow chart showing the substeps of the preparation method for the catalyst for treating nitrogen-containing oxide tail gas according to the first embodiment of the present invention.

Fig. 3 is a schematic view showing the reaction mechanism of the exhaust gas of the second embodiment of the present invention into the catalyst of the first embodiment of the present invention.

Figure 4: The catalyst of Cu-Ce-Fe-Co/TiO ₂ of the first embodiment of the present invention and the catalyst of Mn-Ce-Fe-Co/TiO ₂ of the third embodiment for the test of moisture resistance Compare the graphs.

Figure 5: Comparison of the sulfur-resistant test of the Cu-Ce-Fe-Co/TiO ₂ catalyst of the first embodiment of the present invention and the Mn-Ce-Fe-Co/TiO ₂ catalyst of the third embodiment Figure.

Fig. 6 is a graph showing the results of comparison of a catalyst of Cu-Ce-Fe-Co/TiO ₂ of the first embodiment of the present invention with known techniques.

The above and other objects, features, and advantages of the present invention will become more apparent from In addition, the "%" mentioned in the present invention means "weight percentage (wt%)" unless otherwise specified; the numerical range (such as 10% to 15% of A) includes upper and lower limits unless otherwise specified. (ie 10% ≦A ≦ 15%) and all numerical points in the range (eg 11, 12, 13, 14...) or decimal points (eg 11.1, 12.3, 13.5...); if the range of values is undefined The lower limit (such as B below 0.2%, or B below 0.2%) means that the lower limit may be 0 (ie 0% ≦ B ≦ 0.2%); the ratio of the "weight percentage" of each component Relationships can also be replaced by the proportional relationship of "parts by weight". The above terms are used to illustrate and understand the present invention and are not intended to limit the invention.

Referring to FIG. 1 , a method for preparing a catalyst for treating nitrogen-containing oxide tail gas according to a first embodiment of the present invention is used to prepare a catalyst for use based on a carbon monoxide. Treating a nitrogen-containing oxide tail gas by a selective catalyst reduction method, the method comprising the steps of: providing a carrier; and providing a precursor containing copper, ruthenium, iron, and cobalt, and dissolving the precursor; and, dissolving The precursor is then applied to the carrier and a processing step is performed to form a catalyst. The present invention will be described in detail below with reference to Fig. 1 to explain in detail the implementation details of the above steps of the first embodiment and the principle thereof.

Referring to FIG. 1 , a method for preparing a catalyst for treating nitrogen-containing oxide tail gas according to a first embodiment of the present invention is for preparing a catalyst for treatment by a selective catalyst reduction method by using carbon monoxide. A nitrogen-containing oxide tail gas, first referring to step S11: providing a carrier. In this step, the support is titanium dioxide (TiO ₂ ). Alternatively, the support may be cerium oxide (SiO ₂ ). Next, referring to step S12, a precursor containing copper, ruthenium, iron, and cobalt is provided, and the precursor is dissolved and uniformly mixed. In this step, the precursor containing copper, ruthenium, iron and cobalt is present in the form of a metal nitrate salt. Preferably, the catalyst composition is such that the precursor containing copper, cerium, iron and cobalt is supported on the body by 10% by weight of the total weight. For example, it is necessary to prepare "Cu-Ce-Fe-Co/TiO ₂ " with a total weight of 30 grams, and it is necessary to weigh 27 g of TiO ₂ as a carrier and another 3 g of active phase (Cu-Ce-Fe-Co). On the TiO ₂ support. Preferably, the weight ratio of the active phase of one of the precursors of copper, bismuth, iron and cobalt is 1:1:1:1 to 1:2.3:1:1. For example, the precursor containing copper, ruthenium, iron, and cobalt is a 1:1:1:1 metal ratio, different nitrate metal salts to make a total weight of 3 grams of the precursor. Table 3 below shows the specifications and suppliers of the raw materials for the preparation of the catalyst according to the first embodiment of the present invention.

The addition amount of the nitrate metal salt is calculated as follows: the required number of grams of Cu is 0.75 g, so 0.75 g × 241.60 g / mol (molecular weight of copper nitrate) ÷ 63.546 g / mol (molecular weight of copper) ÷ 1 (purity of copper nitrate) ) = 2.85 g (copper nitrate addition); the required number of grams of Co is 0.75 g, so 0.75 g × 291.03 g / mol (cobalt nitrate molecular weight) ÷ 58.933 g / mol (molecular weight of cobalt) ÷ 0.98 (cobalt nitrate purity ) = 3.78 g (cobalt nitrate addition); the required number of grams of Ce is 0.75 g, so 0.75 g × 434.22 g / mol (molecular weight of cerium nitrate) ÷ 140.12 g / mol (molecular weight of cerium) ÷ 0.99 (purity of cerium nitrate) ) = 2.35 g (addition amount of lanthanum nitrate); the required number of grams of Fe is 0.75 g, so 0.75 g × 404.02 (molecular weight of ferric nitrate) ÷ 55.845 g / mol (molecular weight of iron) ÷ 0.99 = 5.48 g (addition of ferric nitrate ). Next, referring to step S13, the dissolved precursor is added to the carrier, and a treatment step is performed to form a catalyst. Referring to FIG. 2, FIG. 2 is a sub-step of step S13 in FIG. 1. As shown in step S131, the scaled metal nitrate precursor is dissolved in deionized water, for example, 15 ml of deionized water. the nitrate precursor sufficiently dissolved, and sufficiently mixed in a crucible, followed by addition of the desired carrier, for example, TiO _2. Next, as shown in step S132, the precursor added to the carrier is heated to 80 ° C and stirred until the sample is in a paste form to form a catalyst precursor; thereafter, as shown in step S133, the catalyst precursor is as shown in step S133. It is placed in an oven and dried at 110 ° C for 24 hours. Then, as shown in step S134, the dried catalyst precursor is taken out and placed in a high temperature calciner at a heating rate of 5 ° C per minute. Heating up and continuously calcining at 400 ° C for 4 hours to form a calcining catalyst; and finally, as shown in step S135, the calcining catalyst is ground and passed through a screen of a specific mesh, preferably, for example, 30 mesh to A screen of 70 mesh size to form the catalyst.

By the above steps, the first embodiment of the present invention can treat a nitrogen-containing oxide tail gas based on a selective catalyst reduction method using the carbon monoxide. Since the catalyst operating temperature can be treated at a lower temperature, it is advantageous to further use one of the carbon dioxide in the exhaust gas as a reducing agent without additionally adding ammonia gas. At the same time, it can also increase the exhaust gas temperature without additional energy consumption.

According to a second embodiment of the present invention, a catalyst prepared by the method for preparing a catalyst according to the first embodiment of the present invention provides a catalyst for reducing nitrogen oxides by selective catalyst reduction by using the catalyst. The method comprises the steps of: providing an exhaust gas containing carbon monoxide and at least one nitrogen oxide; and introducing the exhaust gas into a catalyst containing copper, antimony, iron and cobalt, and the exhaust gas is reduced by using carbon monoxide as a catalyst And a catalyst that is catalyzed by the catalyst to carry out a denitration reaction. Referring to Figure 3, the catalyst is 10% by weight of Cu-Ce-Fe-Co supported on TiO ₂ (abbreviated as 10% Cu-Ce-Fe-Co/TiO ₂ ). As an example of the medium, the reaction mechanism for providing the exhaust gas to the catalyst is as follows: 2NO+2O _vac → N ₂ +2O _ad

2CO+2O _ad → CO ₂ +2O _vac

Net reaction: 2CO + 2NO → N ₂ + 2CO ₂ .

Where O _vac represents the oxygen vacancy (active position) on the surface of the catalyst, and O _ad represents the adsorbed oxygen on the surface of the catalyst.

The method for preparing a catalyst according to the third embodiment of the present invention is similar to the first embodiment of the present invention, and generally uses the same component name and figure number. The third embodiment of the present invention provides a Mn-Ce-Fe-Co/TiO. The catalyst of _2, the catalyst of Cu-Ce-Fe-Co/TiO ₂ of the first embodiment of the present invention and the catalyst of Mn-Ce-Fe-Co/TiO ₂ of the third embodiment of the present invention are hereinafter described. Discussion and comparison. The first embodiment and the third embodiment are also operated under the following operating conditions: a NO concentration of 200 ppm, a CO concentration of 2,000 ppm, and a GHSV (spatial flow rate) of 10,000 h ^-1 , and Mn can be found according to the operation result. -Ce-Fe-Co/TiO ₂ catalyst has a removal efficiency of 98-100% at an operating temperature of 200-250 ° C, and under the same conditions, a Cu-Ce-Fe-Co/TiO ₂ catalyst pair The removal efficiency of NO was 96-100%. The results showed that the activity of Mn-Ce-Fe-Co/TiO ₂ catalyst for NO removal was slightly higher than that of Cu-Ce-Fe-Co/TiO ₂ catalyst.

Please refer to the catalyst of Cu-Ce-Fe-Co/TiO _{2 according to} the first embodiment of the present invention as shown in FIG. 4 and the catalyst of Mn-Ce-Fe-Co/TiO ₂ of the third embodiment. The water resistance test was compared under the following operating conditions: a NO concentration of 200 ppm, a CO concentration of 2,000 ppm, a H ₂ O _(g) concentration of 5%, and a GHSV (spatial flow rate) of 10,000 h ^-1 . It shows the effect of the catalyst activity of Mn-Ce-Fe-Co/TiO ₂ and the catalytic activity of Cu-Ce-Fe-Co/TiO ₂ when H ₂ O _{(g) is} introduced into the CO-SCR system. It is shown that when 5% water vapor is introduced into the gas stream, the conversion efficiency of Mn-Ce-Fe-Co/TiO ₂ catalyst to NO is slightly decreased from 98% to about 90% at the operating temperature of 200 °C. When the water vapor is stopped, the conversion efficiency of NO can be restored to 98% of the original; in addition, the influence of the catalyst of Cu-Ce-Fe-Co/TiO ₂ on water vapor shows Cu-Ce-Fe-Co/ The TiO ₂ catalyst can maintain 95% conversion efficiency to NO in the presence or absence of 5% water vapor. From the above results, it is understood that the Cu-Ce-Fe-Co/TiO ₂ catalyst has better H ₂ O _(g) resistance.

Next, as shown in FIG. 5, the catalyst of Cu-Ce-Fe-Co/TiO _{2 according to} the first embodiment of the present invention and the catalyst of Mn-Ce-Fe-Co/TiO ₂ of the third embodiment are shown. For the sulfur tolerance test, it was operated under the following operating conditions: NO concentration of 200 ppm, CO concentration of 2,000 ppm, and GHSV (space flow rate) of 10,000 h ^-1 when 30 ppm of SO _{2 was} introduced into the CO-SCR system. Effect on the catalytic activity of Mn-Ce-Fe-Co/TiO ₂ catalyst and Cu-Ce-Fe-Co/TiO ₂ . The results show that the conversion efficiency of Mn-Ce-Fe-Co/TiO ₂ catalyst and Cu-Ce-Fe-Co/TiO ₂ catalyst to NO can be maintained when SO _{2 is} not introduced into the CO-SCR system. 97% and 95%. When 30ppm SO _{2 is} introduced into the gas stream, the conversion efficiency of Mn-Ce-Fe-Co/TiO ₂ catalyst to NO will drop sharply to 17% at an operating temperature of 200 ° C. After a period of time, SO _{2 is} stopped from being introduced into the system. In the middle, it can be found that the conversion efficiency of NO has not been significantly restored. On the contrary, the introduction of SO _{2 in} the CO-SCR system of Cu-Ce-Fe-Co/TiO ₂ catalyst under the same conditions revealed that the conversion efficiency of NO did not decrease significantly. The catalyst of Mn-Ce-Fe-Co/TiO ₂ exhibits severe sulfur poisoning under sulfur-containing conditions. This sulfur poisoning may be caused by the formation of sulfur element on the catalyst surface. The mechanism is: 3SO _2(a) → 2SO _{3 (a)} +S _(a) . On the contrary, the catalyst of Cu-Ce-Fe-Co/TiO ₂ has a strong adsorption capacity for NO and CO in the CO-SCR system, so the deactivation phenomenon caused by the adsorption of SO ₂ on the catalyst surface is not obvious. . Therefore, comparing the catalyst of Cu-Ce-Fe-Co/TiO _{2 with} the catalyst of Mn-Ce-Fe-Co/TiO ₂ , it can be found that the catalyst of Cu-Ce-Fe-Co/TiO ₂ is more suitable. Under complex (or actual) exhaust conditions.

As shown in Fig. 6, the Cu-Ce-Fe-Co/TiO ₂ catalyst of the present invention is compared with the known technique, and is operated in the CO-SCR system under the following operating conditions: NO concentration is 200 ppm, CO concentration At 2,000 ppm and an operating temperature of 250 ° C, the Cu-Ce-Fe-Co/TiO ₂ catalyst showed a NO removal efficiency of 100%. In the prior art, the Ir/Al ₂ O ₃ catalyst is operated in the CO-SCR system under the following operating conditions: a NO concentration of 2000 ppm, a CO concentration of 10,000 ppm, and an operating temperature of 400 ° C for a NO removal efficiency of 90. %. The catalysts used in the other three known techniques, such as Pt/TiO ₂ catalysts, are operated in a CO-SCR system under the following operating conditions: a NO concentration of 500 ppm, a CO concentration of 15,000 ppm, and an operating temperature of 400. The removal efficiency of NO at °C was 60%. The catalyst of Pd/Ce _0.6 Zr _0.4 O ₂ was operated in the CO-SCR system under the following operating conditions: a NO concentration of 230 ppm, a CO concentration of 690 ppm, and an NO removal efficiency of 59% at an operating temperature of 400 °C. The Rh/H-Betazeolite catalyst was operated in a CO-SCR system under the following operating conditions: a NO concentration of 500 ppm, a CO concentration of 15,000 ppm, and an NO removal efficiency of 56% at an operating temperature of 350 °C. The results show that the Cu-Ce-Fe-Co/TiO ₂ catalyst of the present invention has significantly better performance in CO-SCR than the catalyst used in the known art.

Compared with the third embodiment, the first embodiment further increases the resistance to moisture and the resistance to sulfide poisoning and loses activity. Thereby, not only complex (or actual) exhaust gas conditions, but also low-temperature treatment of nitrogen-containing oxide tail gas based on selective catalyst reduction, and further use of one of carbon dioxide in the exhaust gas as a reducing agent No additional ammonia is required. At the same time, it is also possible to consume energy without raising the temperature of the exhaust gas, thereby further increasing the operational flexibility and reducing the operating cost.

The present invention has been disclosed in its preferred embodiments, and is not intended to limit the invention, and the present invention may be modified and modified without departing from the spirit and scope of the invention. The scope of protection is subject to the definition of the scope of the patent application.

Claims (10)

A preparation method for treating a nitrogen-containing oxide tail gas for preparing a catalyst for treating a nitrogen-containing oxide tail gas based on a selective catalyst reduction method by using carbon monoxide, the preparation method comprising the steps of: providing a carrier; providing a precursor containing copper, ruthenium, iron, and cobalt, and dissolving the precursor; and applying the dissolved precursor to the support, and performing a processing step to form a catalyst. The method for preparing a catalyst for treating nitrogen-containing oxide tail gas according to claim 1, wherein the precursor containing copper, ruthenium, iron and cobalt is present as a metal nitrate salt. The method for preparing a catalyst for treating nitrogen-containing oxide tail gas according to claim 1, wherein the weight ratio of the active phase of one of copper, bismuth, iron and cobalt of the precursor is 1:1:1. :1 to 1:2.3:1:1. The method for preparing a catalyst for treating nitrogen-containing oxide tail gas according to claim 1, wherein the carrier is titanium dioxide. The method for preparing a catalyst for treating nitrogen-containing oxide tail gas according to claim 1, wherein the treating step comprises the steps of: heating the precursor added to the carrier to 80 ° C and stirring until the sample Presenting a paste to form a catalyst precursor; the catalyst precursor is placed in an oven and dried at 110 ° C for 24 hours; the dried catalyst precursor is taken out and placed in a high temperature forging furnace The temperature was raised at a heating rate of 5 ° C per minute, and calcined at 400 ° C for 4 hours to form a calcined catalyst; and the calcined catalyst was ground to form the catalyst. A method for treating a nitrogen-containing oxide tail gas by a selective catalyst reduction method, comprising the steps of: providing a tail gas containing carbon monoxide and at least one nitrogen oxide; and introducing the tail gas into a catalyst, the catalyst containing copper , hydrazine, iron and cobalt, the tail gas utilizes carbon monoxide as a reducing agent and is catalyzed by the catalyst to carry out a denitration reaction. A method for treating a nitrogen-containing oxide tail gas by a selective catalyst reduction method according to claim 6, wherein one of the carbon oxides contained in the tail gas is produced by incomplete combustion of the exhaust gas. A method for treating a nitrogen-containing oxide tail gas by a selective catalyst reduction method according to claim 6, wherein the catalyst has a weight ratio of one of copper, bismuth, iron and cobalt to 1:1: 1:1 to 1:2.3:1:1. A method for treating a nitrogen-containing oxide tail gas by a selective catalyst reduction method according to claim 6, wherein one of the catalyst carriers is titanium dioxide. A method for treating a nitrogen-containing oxide tail gas by a selective catalyst reduction method according to claim 6, wherein the catalyst has an operating temperature of from 150 ° C to 250 ° C.