阅读说明：本技术 联合评价脱硝脱汞催化剂活性的装置以及评价方法 (Device and method for jointly evaluating activity of denitration and demercuration catalyst ) 是由 王红妍 王宝冬 李永龙 孙琦 徐文强 刘子林 李歌 于 2019-08-29 设计创作，主要内容包括：本发明属于环境保护技术领域,公开了一种联合评价脱硝脱汞催化剂活性的装置以及评价方法。其中,所述装置的结构包括配气单元、反应单元和分析检测单元,所述反应单元包括石英反应器,所述石英反应器包括由内管和外管构成的内外套管,所述内管包括顶端的中间进气口,以及所述外管包括左侧进气口、右侧进气口和下端排气口。该装置稳定可靠、方便实用,通过改变各气相组分浓度来模拟不同燃煤电厂的气氛,以考察筛选联合脱硝脱汞催化剂。(The invention belongs to the technical field of environmental protection, and discloses a device and an evaluation method for jointly evaluating the activity of a denitration and demercuration catalyst. The structure of the device comprises a gas distribution unit, a reaction unit and an analysis detection unit, wherein the reaction unit comprises a quartz reactor, the quartz reactor comprises an inner sleeve and an outer sleeve, the inner sleeve comprises an inner tube and an outer tube, the inner tube comprises a middle gas inlet at the top end, and the outer tube comprises a left gas inlet, a right gas inlet and a lower gas outlet. The device is stable and reliable, convenient and practical, and simulates the atmosphere of different coal-fired power plants by changing the concentration of each gas-phase component so as to investigate and screen the combined denitration and demercuration catalyst.)

1. The device for jointly evaluating the activity of the denitration and demercuration catalyst is characterized in that the device structurally comprises a gas distribution unit, a reaction unit and an analysis detection unit, wherein the reaction unit comprises a quartz reactor (11), the quartz reactor (11) comprises an inner sleeve and an outer sleeve which are composed of an inner tube and an outer tube, the inner tube comprises a middle gas inlet (22) at the top end, and the outer tube comprises a left gas inlet (19), a right gas inlet (20) and a lower gas outlet (21).

2. According to claimThe apparatus of 1, wherein the piping of the apparatus comprises at least a first air intake pipe, a second air intake pipe, and a third air intake pipe; the first air inlet pipeline is composed of N₂The gas tank, the mass flow controller and the mercury evaporation module (3) are connected to form a pipeline I for conveying mercury vapor;

preferably, the outlet line of the mercury evaporation module (3) is provided with a heat tracing band (6);

preferably, the pipeline of the mercury evaporation module (3) is made of polytetrafluoroethylene.

3. The device according to claim 2, wherein the second air intake line is a line II for conveying water vapour formed by the connection of a water intake (4) and a metering pump (5).

4. The apparatus of claim 2, wherein the third air intake line is routed O₂Gas tank, SO₂Gas tank, NO gas tank, and N₂Transfer O formed by gas tank connection₂、SO₂NO and N₂Line III of (a).

5. The apparatus according to claim 1, wherein the gas distribution unit comprises a preheating mixing tank (7) and a heating furnace (10) arranged at the periphery of the preheating mixing tank (7), and a gas inlet coil (9) built in the preheating mixing tank (7); the water vapor conveyed by the second air inlet pipeline and the gas conveyed by the third air inlet pipeline are coiled and preheated in a coil pipe (9) at the middle lower part inside the preheating mixing tank (7) and are uniformly mixed in a mixing tank (8) at the upper part of the preheating mixing tank (7);

preferably, the middle lower part is a middle lower area at 1/2-3/4 of the height of the preheating mixing tank (7).

6. The device according to claim 5, wherein the top end of the preheating mixing tank (7) is provided with an exhaust pipeline, and the outer wall of the exhaust pipeline is wound with a heat tracing band;

preferably, an exhaust pipeline at the top end of the preheating mixing tank (7) is connected with a first air inlet pipeline and is divided into a main pipeline and a bypass through control of electromagnetic valves (12) and (13), wherein the main pipeline is connected with a left air inlet (19) of an outer pipe of the quartz reactor (11), and the bypass is connected with a flue gas analyzer (14) and a mercury analyzer (15).

7. The apparatus according to claim 1, wherein HCl gas is introduced into the inner tube of the quartz reactor (11) from a middle gas inlet (22) at the top end of the inner tube of the quartz reactor (11).

8. The apparatus according to claim 1, wherein NH is introduced from a right side gas inlet (20) of the outer tube of the quartz reactor (11)₃Gas, into the outer tube of the quartz reactor (11).

9. The device according to claim 1 or 6, wherein the flue gas analyzer (14) and the mercury analyzer (15) are further provided with an alkali absorption liquid module (16) and an activated carbon adsorption module (17) connected in series therewith.

10. A method for the combined evaluation of the activity of a denitration and demercuration catalyst, which is carried out in the apparatus as claimed in claims 1 to 9, the method comprising:

(a) placing a catalyst in the quartz reactor (11);

(b) the total power supply is turned on, and carrier gas N is introduced₂Simultaneously adjusting the temperature of the heating furnace (10) and the temperature of the heat tracing band (6);

(c) after the temperatures of the preheating mixing tank (7) and the heat tracing band (6) reach the set temperatures, the pipeline II and the pipeline III are opened, and water vapor and O are introduced₂、SO₂And NO, each gas is spirally preheated at the middle lower part inside the preheating mixing tank (7) and uniformly mixed in a mixing tank (8) at the upper part of the preheating mixing tank (7);

(d) the mixed gas after the step (c) is connected with a pipeline I through an exhaust pipeline arranged at the top end of the preheating mixing tank (7), and then is controlled by electromagnetic valves (12) and (13) to be divided into a main branch and a bypass branch, wherein the bypass directly enters a flue gas analyzer (14) and a mercury analyzer (15), and the content of each gas component in the original gas is recorded after the numerical value is stabilized;

(e) controlling the solenoid valves (12) and (13), closing the bypass, opening the main circuit, regulating the temperature of the furnace (18), while introducing NH₃And HCl, NH regulated by a mass flow meter₃And HCl gas flow, the gas enters the quartz reactor (11) together with the gas discharged from the preheating mixing tank (7) and the gas in the pipeline I, and reacts under the action of a catalyst;

(f) the gas after catalytic reaction enters the flue gas analyzer (14) and the mercury analyzer (15), and after the numerical value of the analyzers is stable, the content of each component in the gas after reaction is recorded;

(g) comparing data collected before and after the catalytic reaction, and calculating the activity of the catalyst;

(h) after the experiment was finished, N was used₂Purging the system, closing each instrument, and discharging the catalyst after the quartz reactor (11) is cooled.

11. The method as claimed in claim 10, wherein the temperature of the heating furnace (18) is 200-550 ℃.

Technical Field

The invention relates to the technical field of environmental protection, in particular to a device and a method for jointly evaluating the activity of a denitration and demercuration catalyst.

Background

The combustion of coal emits large amounts of pollutants, such as Nitrogen Oxides (NO), into the atmosphere_x) And heavy metal mercury (Hg), etc., which are harmful to the environment and human health. NO_xIs an important precursor for causing regional dust haze, acid rain, photochemical smog and the like. Mercury is also receiving more and more attention from the international society because of its extremely strong volatility, durability, strong toxicity and biological enrichment effect. Thus, strengthening the coal NO_xAnd mercury control is imminent.

According to the relevant regulations, the emission of mercury and its compounds from coal-fired boilers is limited to 30 μ g/m³. In addition, new requirements are put on emission of the coal-fired unit, and NO of the unit within the requirements_xThe discharge amount is less than 50mg/Nm³. This undoubtedly has more strict requirements on the flue gas denitration and demercuration technology.

At present, most of the existing domestic combined evaluation devices are single combined evaluation devices for denitration or demercuration, and due to various reasons such as gas mixing, mutual interference and other factors, the detection of denitration and demercuration activity and accuracy is difficult to realize, so that NO can be prevented_xThe development of the combined removal technology of Hg and Hg is greatly restricted. Compared with the denitration and demercuration technology which is independently applied, the combined denitration and demercuration technology has the advantages in the aspects of economy and resource utilization efficiency.

CN204065045U discloses a denitration demercuration catalyst activity evaluation device, contains gas supply system, reaction system and detecting system, and the device selects out the catalyst that flue gas denitration and demercuration effect are all good through simulating coal-fired flue gas. But mercury oxidation requires the participation of HCl gas during the evaluation,NH of HCl gas inevitably reacts with SCR in the reactor₃The reaction occurs, the evaluation result of the denitration and demercuration performance of the catalyst is influenced, and the device does not consider the H in the actual flue gas₂The influence of O.

CN103926370B also discloses an apparatus and a method for combined evaluation of denitration and demercuration performance of catalyst, which takes NH into account₃Interaction with HCl, but NH₃The reaction still occurs after the contact with HCl at the upper part of the reactor, which affects the real evaluation result. In addition, in the device, the Hg vapor entering the preheating mixing tank during the mixing process can be adsorbed on the wall of the mixing tank, and the H in the actual flue gas is not considered₂The influence of O cannot truly simulate the actual smoke.

Therefore, the research and development of the device and the method for jointly evaluating the activity of the denitration and demercuration catalyst with high anti-interference accuracy have important significance.

Disclosure of Invention

The invention aims to overcome the defect that in the device and the method for jointly evaluating the activity of the denitration and demercuration catalyst in the prior art, HCl gas can react with NH of SCR in the evaluation process₃、H₂The device is stable, reliable, convenient and practical, and simulates the atmospheres of different coal-fired power plants by changing the concentration of each gas-phase component so as to investigate and screen the combined denitration and demercuration catalyst.

In order to achieve the above object, the first aspect of the present invention provides an apparatus for jointly evaluating the activity of a denitration and demercuration catalyst, the apparatus comprises a gas distribution unit, a reaction unit and an analysis and detection unit, the reaction unit comprises a quartz reactor 11, the quartz reactor 11 comprises an inner casing and an outer casing, the inner casing comprises an inner pipe and an outer pipe, the inner pipe comprises a middle gas inlet 22 at the top end, and the outer pipe comprises a left gas inlet 19, a right gas inlet 20 and a lower gas outlet 21.

The invention provides a method for jointly evaluating the activity of a denitration and demercuration catalyst, wherein the method is carried out in the device, and the method comprises the following steps:

(a) placing a catalyst in the quartz reactor 11;

(b) the total power supply is turned on, and carrier gas N is introduced₂Adjusting the temperature of the heating furnace 10 and the heat tracing band 6 simultaneously;

(c) after the temperatures of the preheating mixing tank 7 and the heat tracing band 6 reach the set temperatures, the pipeline II and the pipeline III are opened, and water vapor and O are introduced₂、SO₂And NO, each gas is spirally preheated at the middle lower part inside the preheating mixing tank 7 and uniformly mixed in a mixing tank 8 at the upper part of the preheating mixing tank 7;

(d) the mixed gas after the step (c) is connected with a pipeline I through an exhaust pipeline arranged at the top end of the preheating mixing tank 7 and then is controlled by electromagnetic valves 12 and 13 to be divided into a main pipeline and a bypass pipeline, wherein the bypass pipeline directly enters a flue gas analyzer 14 and a mercury analyzer 15, and the content of each gas component in the original gas is recorded after the numerical value is stabilized;

(e) controlling the solenoid valves 12 and 13, closing the bypass, opening the main circuit, regulating the temperature of the furnace 18, while introducing NH₃And HCl, NH regulated by a mass flow meter₃And HCl gas flow, the gas enters the quartz reactor 11 together with the gas discharged from the preheating mixing tank 7 and the gas in the pipeline I, and reacts under the action of a catalyst;

(f) the gas after the catalytic reaction enters the flue gas analyzer 14 and the mercury analyzer 15, and after the numerical values of the analyzers are stable, the content of each component in the gas after the reaction is recorded;

(g) comparing data collected before and after the catalytic reaction, and calculating the activity of the catalyst;

(h) after the experiment was finished, N was used₂Purging the system, closing each instrument, and discharging the catalyst after the quartz reactor 11 is cooled.

Through the technical scheme, the device is simple in structure arrangement, can conveniently, quickly and stably generate smoke with different proportions, and simulates out fuelThe actual flue gas condition of the coal power plant is used for detecting NO in the flue gas in real time through the matching of the valve, the flue gas analyzer and the mercury analyzer_xAnd Hg⁰The concentration of (c). By replacing different types of catalysts, the catalyst with good denitration and demercuration effects for specific flue gas is selected. Through gas mixing mode and reactor design, better solution flue gas mix and the problem of mutual interference, the evaluation result is more accurate. The pipeline design is convenient and practical, and is acid-resistant and high-temperature-resistant (less than 200 ℃); the tail gas treatment system is perfect, the complex gas after reaction and detection is well treated, and the pollution to the atmospheric environment can be effectively avoided. Therefore, the invention has more comprehensiveness and practicability.

Drawings

FIG. 1 is a schematic diagram of an apparatus for the combined evaluation of the activity of a denitration and demercuration catalyst according to the present invention;

fig. 2 is a schematic view of the structure of the quartz reactor 11 of the present invention.

Description of the reference numerals

1-gas tank 2-mass flow controller 3-mercury evaporation module 4-water inlet device

5-metering pump 6-heat tracing band 7-preheating mixing tank 8-mixing area

9-air inlet coil pipe 10-heating furnace 11-quartz reaction tube 12-electromagnetic valve

13-solenoid valve 14-flue gas analyzer 15-mercury analyzer 16-alkali absorption liquid module

17-activated carbon adsorption module

Detailed Description

The endpoints of the ranges and any values disclosed herein are not limited to the precise range or value, and such ranges or values should be understood to encompass values close to those ranges or values. For ranges of values, between the endpoints of each of the ranges and the individual points, and between the individual points may be combined with each other to give one or more new ranges of values, and these ranges of values should be considered as specifically disclosed herein.

The invention provides a device for jointly evaluating the activity of a denitration and demercuration catalyst, wherein the device structurally comprises a gas distribution unit, a reaction unit and an analysis detection unit, the reaction unit comprises a quartz reactor 11, as shown in fig. 2, the quartz reactor 11 comprises an inner sleeve and an outer sleeve, the inner sleeve is composed of an inner tube and an outer tube, the inner tube comprises a middle gas inlet 22 at the top end, and the outer tube comprises a left gas inlet 19, a right gas inlet 20 and a lower gas outlet 21.

According to the invention, in the present invention, the description is made with reference to fig. 1 and 2.

According to the invention, the pipes (air intake pipes) of the device comprise at least a first air intake pipe, a second air intake pipe and a third air intake pipe.

According to the invention, the first inlet line is connected to the first inlet line by a line N₂The gas tank, the mass flow controller and the mercury evaporation module 3 are connected to form a pipeline I for conveying mercury vapor.

According to the invention, said N₂One outlet pipeline of the gas tank is connected with an inlet pipeline of the mercury evaporation module 3 through a mass flow controller, and the outlet pipeline of the mercury evaporation module 3 and the first gas inlet pipeline are connected to a gas exhaust pipeline at the top end of the preheating mixing tank 7; in the present invention, the outlet duct of the mercury evaporation module 3 may be preferably provided with a heat tracing band 6, in the present invention at a constant temperature and a constant N₂Under the flow, the mercury evaporation module 3 adopts an electric heating mode, and the exhaust pipelines from the outlet of the mercury evaporation module 3 to the top end of the preheating mixing tank are all provided with the heat tracing bands 6, so that the mercury exists in a vapor form, and the pipelines of the mercury evaporation module 3 are made of polytetrafluoroethylene materials, so that the mercury vapor adsorption can be effectively avoided.

According to the invention, the second air inlet pipeline is a pipeline II which is formed by connecting a water inlet device 4 and a metering pump 5 and is used for conveying water vapor; in the invention, the metering pump 5 can control the flow rate of the water in the water inlet device 4, and the outlet pipeline of the water inlet device 4 and the second air inlet pipeline can be connected to an air inlet coil 9 in the preheating mixing tank 7Performing the following steps; in the present invention, H in flue gas is preferably simulated₂The O is fully preheated and gasified through an air inlet coil pipe 9, and finally fully mixed in a mixing area 8 at the upper end part of a preheating mixing tank 7. In the present invention, it should be noted that the water vapor is provided by injecting water into the gas path quantitatively by a metering pump and gasifying the water at a high temperature.

According to the invention, said third intake line is constituted by₂Gas tank, SO₂Gas tank, NO gas tank, and N₂Transfer O formed by gas tank connection₂、SO₂NO and N₂Line III of (2); preferably, O₂Gas tank, SO₂Gas tank, NO gas tank, and N₂The respective outlet pipes of the gas tanks pass through respective mass flow controllers respectively and are collected and then coiled in an air inlet coil pipe 9 in the preheating mixing tank 7 for full preheating and then enter the mixing area 8. As shown in FIG. 1, O₂、SO₂NO and N₂The simulated flue gas components are respectively placed in a gas tank, the gas tank can be used for storing standard gas and simulating hydrogen chloride, oxygen, sulfur dioxide, nitric oxide and nitrogen in the flue gas, the flow of each gas is accurately controlled by a respective mass flow controller, and the simulated flue gas components firstly enter a preheating mixing tank 7 after passing through the respective mass flow controllers and before entering a quartz reactor 11 so as to preheat and fully mix the gas components; in the present invention, it is preferable to simulate the gas (O) in the flue gas for sufficient preheating of each gas component₂、SO₂NO and N₂) The mixture is preheated in an air inlet coil 9 and finally fully mixed with water vapor in a mixing area 8 at the upper end part of the preheating mixing tank 7.

In the invention, the mercury vapor removing gas circuit adopts a polytetrafluoroethylene tube, and other gas circuits all adopt stainless steel tubes, so as to reduce the influence of physicochemical reaction of the tube wall and the device body examination on gas components.

The gas distribution unit comprises a preheating mixing tank 7, a heating furnace 10 arranged on the periphery of the preheating mixing tank 7 and an air inlet coil 9 arranged in the preheating mixing tank 7; wherein, the water vapor conveyed by the second air inlet pipeline and the gas conveyed by the third air inlet pipeline are preheated in a coil pipe 9 at the middle lower part inside the preheating mixing tank 7 in a spiral way and are uniformly mixed in a mixing tank 8 at the upper part of the preheating mixing tank 7; preferably, the lower middle position is a region at 1/2-3/4 of the height of the preheating mixing tank 7.

According to the invention, the top end of the preheating mixing tank 7 is provided with an exhaust pipeline, and the outer wall of the exhaust pipeline is wound with a heat tracing band; preferably, the exhaust pipeline at the top end of the preheating mixing tank 7 is connected with the first air inlet pipeline, and is controlled by the electromagnetic valve 12 to be divided into a main pipeline and a bypass, wherein the main pipeline is connected with a left air inlet 19 of the outer pipe of the quartz reactor 11, and the bypass is controlled by the electromagnetic valve 13 to be connected with the flue gas analyzer 14 and the mercury analyzer 15; in the invention, preferably, the outer wall of the exhaust pipeline is wound with a heat tracing band, so that gas condensation and adsorption can be effectively avoided.

According to the invention, the simulated flue gas (N) in the mixing tank 7 is preferably preheated₂、O₂、NO、SO₂And H₂O) and Hg vapor are mixed and then enter the outer tube of the quartz reactor 11 from the left air inlet of the outer tube, NH₃The HCl enters the outer tube from a right gas inlet 19 of the outer tube of the quartz reactor 11, and the HCl enters the inner tube from a middle gas inlet 22 of the inner tube of the quartz reactor 11; the end of the inner tube is positioned inside the outer tube, above the catalyst, to minimize NH₃Interference with HCl.

According to the invention, a quartz sand sieve plate is arranged on the inner wall of the outer tube, wherein the catalyst can be placed on the quartz sand sieve plate, i.e. the quartz sand sieve plate can be used for carrying the catalyst. In addition, in the present invention, the quartz sand sieve plate carrying the catalyst is located in the constant temperature zone and fixed at the inner wall of the outer tube and the lower portion of the inner tube. The bottom of the quartz reactor is provided with an air outlet which is connected with a subsequent analysis and detection unit.

According to the present invention, the quartz reactor 11 may be provided at the periphery thereof with a heating furnace 18 for heating the quartz reactor 11.

According to the invention, the flue gas analyzer 14 and the mercury analyzer 15 may also be provided with an alkali absorption liquid module 16 and an activated carbon adsorption module 17 connected in sequence thereto.

According to the invention, the device comprises NH₃A gas tank, and the NH₃NH in gas cylinders₃The gas inlet 20 through the right side of the outer tube of the quartz reactor 11 may directly enter the outer tube of the quartz reactor 11.

According to the invention, the device comprises a HCl gas tank, and HCl in the HCl gas tank can enter the inner tube of the quartz reactor 11 directly via the intermediate gas inlet 22 of the inner tube of the quartz reactor 11.

According to the invention, the device also comprises a reaction unit and an analytical detection unit.

In the invention, the distribution of the gas in the invention refers to the actual atmosphere condition in the SCR reactor of the coal-fired power plant, so that the denitration and demercuration activity of the prepared catalyst can be conveniently and quickly evaluated, and the accuracy is high.

Wherein, the analysis and detection unit comprises a flue gas analyzer 14 and a mercury analyzer 15, and a gas sampling point is arranged at a gas outlet close to the lower end of the quartz reactor 11. In addition, the analysis and detection unit further comprises a tail gas treatment system, and the analyzed gas sequentially passes through the alkali absorption liquid 16 and the activated carbon adsorption device 17 to absorb and purify a small amount of residual harmful gas components in the tail gas. In the invention, the tail gas treatment system is perfect, has better treatment effect on the detected complex gas, and can effectively avoid the pollution to the atmospheric environment. Therefore, the invention has more comprehensiveness and practicability.

The invention provides a method for jointly evaluating the activity of a denitration and demercuration catalyst, wherein the method is carried out in the device, and the method comprises the following steps:

(a) placing a catalyst in the quartz reactor 11;

(b) the total power supply is turned on, and carrier gas N is introduced₂Adjusting the temperature of the heating furnace 10 and the heat tracing band 6 simultaneously;

(c) the temperature of the mixing tank 7 and the heat tracing band 6 is to be preheatedAfter the temperature reaches the set temperature, opening the pipeline II and the pipeline III, and introducing water vapor and O₂、SO₂And NO, each gas is spirally preheated at the middle lower part inside the preheating mixing tank 7 and uniformly mixed in a mixing tank 8 at the upper part of the preheating mixing tank 7;

(d) the mixed gas after the step (c) is connected with a pipeline I through an exhaust pipeline arranged at the top end of the preheating mixing tank 7 and then is controlled by electromagnetic valves 12 and 13 to be divided into a main pipeline and a bypass pipeline, wherein the bypass pipeline directly enters a flue gas analyzer 14 and a mercury analyzer 15, and the content of each gas component in the original gas is recorded after the numerical value is stabilized;

(e) controlling the solenoid valves 12 and 13, closing the bypass, opening the main circuit, regulating the temperature of the furnace 18, while introducing NH₃And HCl, NH regulated by a mass flow meter₃And HCl gas flow, the gas enters the quartz reactor 11 together with the gas discharged from the preheating mixing tank 7 and the gas in the pipeline I, and reacts under the action of a catalyst;

(f) the gas after the catalytic reaction enters the flue gas analyzer 14 and the mercury analyzer 15, and after the numerical values of the analyzers are stable, the content of each component in the gas after the reaction is recorded;

(g) comparing data collected before and after the catalytic reaction, and calculating the activity of the catalyst;

(h) after the experiment was finished, N was used₂Purging the system, closing each instrument, and discharging the catalyst after the quartz reactor 11 is cooled.

According to the invention, in the method for jointly evaluating the activity of the denitration and demercuration catalyst, the temperature of the heating furnace 18 is 200-550 ℃, and preferably 200-380 ℃.

According to the invention, the catalyst, the gas phase composition and the reaction temperature can be changed according to the research requirements, so that the catalyst suitable under different working conditions can be screened.

The present invention will be described in detail below by way of examples.

Example 1

This example illustrates the method of evaluating the activity of a denitration and demercuration catalyst in combination with the apparatus of the present invention.

As shown in fig. 1 and 2:

(a) adding a catalyst sample into the outer tube of the quartz reactor 11, and slightly rapping the outer tube of the quartz reactor 11 to uniformly distribute the catalyst on a quartz sand sieve plate;

(b) the total power supply is turned on, and carrier gas N is introduced₂Simultaneously adjusting the temperature of a heating furnace 10 at the periphery of the preheating mixing tank 7 and the temperature of the heat tracing band 6;

(c) after the preheating mixing tank 7 and the heat tracing band 6 reach the set temperature respectively, opening a pipeline II and a pipeline III, and introducing NO and SO₂、O₂And the steam enables the gases to be spirally preheated in a middle-lower air inlet coil pipe 9 in the preheating mixing tank 7 and uniformly mixed in a mixing tank (8) at the upper part of the preheating mixing tank 7;

(d) the mixed gas after the step (c) is connected with a pipeline I through an exhaust pipeline arranged at the top end of the preheating mixing tank 7 and then is controlled by electromagnetic valves 12 and 13 to be divided into a main pipeline and a bypass pipeline, wherein the bypass pipeline directly enters the flue gas analyzer 14 and the mercury analyzer 15, the concentration of NO and Hg in the original gas is recorded after the numerical value is stabilized, the NO is 310ppm, and the Hg is 75.9ug/m³；

(e) Controlling the electromagnetic valves 12 and 13, closing the bypass, opening the main path, adjusting the temperature of the heating furnace 18 to 380 ℃, and simultaneously starting NH₃And HCl, NH regulated by a mass flow meter₃And HCl gas flow, the gas enters the quartz reactor 11 together with the gas discharged from the preheating mixing tank 7 and the gas in the pipeline I, and reacts under the action of a catalyst;

(f) the gas after the catalytic reaction enters the flue gas analyzer 14 and the mercury analyzer 15, after the numerical values of the analyzers are stable, the concentrations of NO and Hg in the original gas in the gas after the reaction are recorded, wherein the NO is 79ppm, and the Hg is 20.7ug/m³；

(g) And comparing the data collected before and after the catalytic reaction, and calculating the activity of the catalyst, wherein the denitration rate of the catalyst is 74.5%, and the demercuration rate is 72.7%.

(h) After the experiment was finished, N was used₂Purging the system, closing each instrument, and discharging the catalyst after the quartz reactor 11 is cooled.

The device is stable, reliable, convenient and practical, and can change the concentration of each gas phase component (75.0 μ g/m)³Hg⁰,3％O₂,5ppm HCl,300ppm NO,NH₃/NO:1/1,500ppm SO₂,8％H₂O) to simulate the atmosphere of different coal-fired power plants so as to investigate and screen the combined denitration and demercuration catalyst.

Example 2

This example illustrates the method of evaluating the activity of a denitration and demercuration catalyst in combination with the apparatus of the present invention.

The denitration and demercuration catalyst activity was evaluated in combination in the same manner as in example 1, except that: gas phase composition 75.0. mu.g/m³Hg⁰,3％O₂,5ppm HCl,300ppm NO,NH₃/NO:1/1,1000ppm SO₂,8％H₂O; the reaction temperature was 320 ℃.

The device is stable and reliable, convenient and practical, and the denitration rate and the demercuration rate are respectively 65.3 percent and 15.5 percent.

And screening out a proper combined denitration and demercuration catalyst under the high-sulfur working condition.

Example 3

This example illustrates the method of evaluating the activity of a denitration and demercuration catalyst in combination with the apparatus of the present invention.

The denitration and demercuration catalyst activity was evaluated in combination in the same manner as in example 1, except that: gas phase composition 75.0. mu.g/m³Hg⁰,3％O₂,2ppm HCl,300ppm NO,NH₃/NO:1/1,500ppm SO₂,8％H₂O; the reaction temperature was 200 ℃.

The device is stable and reliable, convenient and practical, and the denitration rate and the demercuration rate are respectively 25.3 percent and 59.1 percent. And screening out a proper combined denitration and demercuration catalyst under the low-chlorine coal combustion flue gas.

Comparative example 1

Using prior artCN204065045U apparatus, according to the same fume conditions as in example 1, the result is due to NH₃The catalyst reacts with HCl, so that the denitration rate and the demercuration rate are both low, and the error is large. The proper catalyst can not be screened out under the condition of meeting the actual working condition of the flue gas.

Comparative example 2

The same fume conditions as in example 1 were followed using a prior art CN103926370B unit (or a unit according to CN103926370B as provided in the background), resulting in a lower concentration of Hg in the gas due to the adsorption of Hg vapour on the mixing tank, and at the same time due to NH₃The catalyst reacts with HCl at the upper end of the reactor, so that the denitration rate and the demercuration rate are both low, corresponding coal-fired flue gas cannot be truly simulated, and a proper catalyst meeting the actual flue gas working condition cannot be screened out.

The results of the embodiment and the comparative example show that the device provided by the invention simulates the atmospheres of different coal-fired power plants by changing the concentration of each gas-phase component so as to investigate and screen the combined denitration and demercuration catalyst, and is stable, reliable, convenient and practical.

The preferred embodiments of the present invention have been described above in detail, but the present invention is not limited thereto. Within the scope of the technical idea of the invention, many simple modifications can be made to the technical solution of the invention, including combinations of various technical features in any other suitable way, and these simple modifications and combinations should also be regarded as the disclosure of the invention, and all fall within the scope of the invention.