Systems and methods for monitoring elemental mercury, divalent mercury, and particulate mercury from stationary pollution sources

Abstract

The application discloses a monitoring system and method for elemental mercury, divalent mercury and particulate mercury of stationary sources, which comprises a filter, a shunt pipeline, a converter and an elemental mercury analyzer. The emission exhaust gas enters the shunt pipeline through the filter, and the filter is used to capture the particulate mercury in the emission exhaust gas. The shunt pipeline comprises a first branch, a second branch and a third branch which are connected in parallel. A divalent mercury absorption bottle is arranged on the first branch, so that the gas at the outlet of the first branch is gaseous elemental mercury. The converter is arranged on the second branch. A divalent mercury reduction bottle is arranged on the third branch. The outlets of the first branch, the second branch and the third branch are connected with the inlet of the elemental mercury analyzer respectively. The outlet of the elemental mercury analyzer is connected with an adsorber, and the outlet of the adsorber is connected with the atmosphere. The monitoring system and method for elemental mercury, divalent mercury and particulate mercury of stationary sources provided by the application have the advantages of distinguishing different forms of mercury, accurate measurement and convenient use.

Description

Technical Field

[0001] This invention relates to the field of pollutant emission monitoring technology, and in particular to a system and method for monitoring elemental mercury, divalent mercury and particulate mercury from stationary pollution sources. Background Technology

[0002] Mercury pollution is primarily found in atmospheric mercury emissions, necessitating mercury monitoring in coal-fired power plants, cement production, metal smelting, and waste incineration. Mercury in exhaust gases from stationary pollution sources exists mainly in three forms: gaseous elemental mercury (Hg). 0 Gaseous divalent mercury (Hg) 2+ ) and particulate mercury (Hg P The three forms of mercury exhibit significantly different physicochemical properties, with varying environmental behaviors, toxicity, and removal difficulties. Currently, online monitoring systems can only detect gaseous total mercury, unable to distinguish between elemental mercury and divalent mercury, and cannot simultaneously detect particulate mercury. Particulate mercury typically requires separate sampling, offline digestion, and subsequent measurement, making real-time online monitoring impossible. Summary of the Invention

[0003] This invention is based on the inventor's discoveries and understanding of the following facts and problems:

[0004] Mercury monitoring requires the monitoring of various forms of mercury.

[0005] The present invention aims to at least partially solve one of the technical problems in the related art.

[0006] Therefore, embodiments of the present invention propose a monitoring system for elemental mercury, divalent mercury, and particulate mercury from a stationary pollution source, comprising a filter, a diversion pipeline, a converter, and an elemental mercury analyzer. Exhaust gas passes through the filter and enters the diversion pipeline. The filter is used to capture particulate mercury in the exhaust gas. The diversion pipeline includes a first branch, a second branch, and a third branch connected in parallel. A divalent mercury absorption bottle is installed on the first branch to absorb gaseous divalent mercury in the exhaust gas, resulting in gaseous elemental mercury at the outlet of the first branch. A converter is installed on the second branch to convert particulate mercury from the filter into gaseous elemental mercury. A divalent mercury reduction bottle is installed on the third branch to reduce gaseous divalent mercury in the exhaust gas back to gaseous elemental mercury. The outlets of the first, second, and third branches are respectively connected to the inlet of the elemental mercury analyzer. The outlet of the elemental mercury analyzer is connected to an adsorber, and the outlet of the adsorber is open to the atmosphere.

[0007] The present invention has the advantages and technical effects of distinguishing different forms of mercury, accurate measurement, and convenient use.

[0008] In some embodiments, the diversion pipeline further includes an intake four-way valve and an exhaust four-way valve. The intake four-way valve is connected to the inlet of the first branch, the second branch and the third branch and the outlet of the filter. The exhaust four-way valve is connected to the outlet of the first branch, the second branch and the third branch and the inlet of the elemental mercury analyzer.

[0009] In some embodiments, the inlet of the divalent mercury absorption bottle is connected to the divalent mercury absorption liquid storage tank, and the outlet of the divalent mercury absorption bottle is used to discharge the first waste liquid.

[0010] In some embodiments, the inlet of the divalent mercury reduction bottle is connected to the divalent mercury reduction solution storage tank, and the outlet of the divalent mercury reduction bottle is used to discharge the second waste liquid.

[0011] In some embodiments, a filter element and a temperature-controlled heater are arranged sequentially from top to bottom inside the filter, a backflush air intake is provided at the top of the filter, and a backflush exhaust is provided at the bottom of the filter.

[0012] In some embodiments, an intake valve is provided on the inlet pipe of the filter to control the entry of exhaust gas.

[0013] In some embodiments, the carrier gas is connected to the inlet pipe between the intake valve and the filter, and the carrier gas is connected to a carrier gas source.

[0014] In some embodiments, the adsorber is filled with activated carbon or a modified mercury adsorbent.

[0015] Embodiments of the present invention provide a method for monitoring elemental mercury, divalent mercury, and particulate mercury from stationary pollution sources, comprising the following steps: The exhaust gas is sent into the filter, and the gaseous mercury in the exhaust gas enters the first and third branches of the diversion pipeline respectively, while the particulate mercury in the exhaust gas is trapped on the filter element of the filter. When the exhaust gas passes through the first branch, the divalent mercury absorption bottle on the first branch absorbs the gaseous divalent mercury in the exhaust gas, and the outlet gas enters the elemental mercury analyzer to measure the concentration of gaseous elemental mercury; when the exhaust gas passes through the third branch, the divalent mercury reduction bottle on the third branch reduces the gaseous divalent mercury in the exhaust gas to gaseous elemental mercury, and the outlet gas enters the elemental mercury analyzer to measure the concentration of total gaseous mercury. The air intake of the closed filter is stopped, and the filter is backflushed to blow the particulate mercury on the filter element into the second branch of the diversion pipeline. After passing through the converter in the second branch, the particulate mercury is converted into gaseous elemental mercury. The gaseous elemental mercury enters the elemental mercury analyzer to measure the concentration of particulate mercury. To calculate the concentration of gaseous divalent mercury, the difference between the total gaseous mercury concentration and elemental mercury is the concentration of gaseous divalent mercury. The outlet gas of the elemental mercury analyzer is sent to an adsorber for adsorption treatment before being released into the atmosphere.

[0016] In some embodiments, before and / or after detection, a carrier gas positioned between the sampling line and the filter is used to purge and clean the split line, and / or to perform zero-point calibration on the elemental mercury analyzer.

[0017] This application offers the following advantages: It introduces a filter to capture particulate mercury; three parallel branches are respectively equipped with a divalent mercury absorption bottle, a particulate mercury converter, and a divalent mercury reduction bottle, all sharing the same elemental mercury analyzer to achieve simultaneous detection of three forms of mercury, reducing system costs and improving measurement accuracy. An inlet four-way valve and an exhaust four-way valve control the switching of gases in the three branches, avoiding cross-contamination between branches and improving detection reliability. The divalent mercury absorption bottle is connected to the absorbent storage tank to discharge the first waste liquid, achieving continuous replenishment of the absorbent liquid and automatic discharge of waste liquid, ensuring stable absorption efficiency. The divalent mercury reduction bottle is connected to the reducing liquid storage tank to discharge the second waste liquid, achieving continuous replenishment of the reducing liquid and timely removal of byproducts, ensuring complete reduction of divalent mercury. The filter is equipped with a filter element and a temperature-controlled heater to prevent water vapor condensation and premature conversion of particulate mercury, enabling online transfer detection of particulate mercury through backflushing. An inlet valve is installed on the inlet pipeline to control the entry of waste gas, providing isolation conditions for backflushing operations and system purging, preventing backflow of the carrier gas, and connecting the inlet valve and filter pipelines for purging cleaning and zero-point calibration of the elemental mercury analyzer. The adsorber is filled with activated carbon or modified mercury adsorbent to adsorb residual mercury in the exhaust gas and prevent secondary pollution. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of a monitoring system for fixed pollution source elements, divalent mercury, and particulate mercury according to an embodiment of the present invention.

[0019] Figure reference numerals: 1. Exhaust gas; 2. Inlet valve; 3. Carrier gas; 4. Filter; 5. Backflush intake; 6. Backflush exhaust; 7. Filter element; 8. Temperature-controlled heater; 9. Inlet four-way valve; 90. Exhaust four-way valve; 91. Inlet elemental mercury side; 92. Inlet total mercury side; 93. Inlet particulate mercury side; 94. Outlet elemental mercury side; 95. Outlet particulate mercury side; 96. Outlet total mercury side; 10. Divalent mercury absorption liquid storage tank; 11. Divalent mercury reduction liquid storage tank; 12. First transfer pump; 13. Second transfer pump; 14. Divalent mercury absorption bottle; 15. Divalent mercury reduction bottle; 16. First waste liquid; 17. Second waste liquid; 18. Elemental mercury analyzer; 19. Adsorbent; 20. Converter. Detailed Implementation

[0020] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0021] An embodiment of the present invention proposes a monitoring system for elemental mercury, divalent mercury, and particulate mercury from a stationary pollution source, comprising a filter 4, a diversion pipeline, a converter 20, and an elemental mercury analyzer 18. Exhaust gas 1 enters the diversion pipeline after passing through the filter 4. The filter 4 is used to capture particulate mercury in the exhaust gas 1. The diversion pipeline includes a first branch, a second branch, and a third branch connected in parallel. A divalent mercury absorption bottle 14 is installed on the first branch to absorb gaseous divalent mercury in the exhaust gas, resulting in gaseous elemental mercury at the outlet of the first branch. A converter 20 is installed on the second branch to convert particulate mercury from the filter 4 into gaseous elemental mercury. A divalent mercury reduction bottle 15 is installed on the third branch to reduce gaseous divalent mercury in the exhaust gas back to gaseous elemental mercury. The outlets of the first, second, and third branches are respectively connected to the inlet of the elemental mercury analyzer 18. The outlet of the elemental mercury analyzer 18 is connected to an adsorber, and the outlet of the adsorber is open to the atmosphere.

[0022] Exhaust gas 1 passes through filter 4, which captures particulate mercury in the exhaust gas, preventing particulate mercury from entering subsequent gas paths and causing interference, and providing a sample source for the separate detection of particulate mercury. The diversion pipeline includes a first branch, a second branch, and a third branch connected in parallel. Controlling the on / off state of the three parallel branches allows for the separate testing of particulate mercury and gaseous mercury. The first branch is equipped with a divalent mercury absorption bottle 14 to absorb gaseous divalent mercury in the exhaust gas, ensuring that the outlet gas of the first branch is only gaseous elemental mercury, thereby achieving direct measurement of gaseous elemental mercury. The second branch is equipped with a converter 20 to convert the particulate mercury from filter 4. The converter 20, which operates at temperatures above 700 degrees Celsius, is for gaseous elemental mercury, solving the problem of online monitoring systems being unable to detect particulate mercury. Combined with carrier gas blowing, online detection of particulate mercury is possible. A third branch includes a divalent mercury reduction bottle 15 to reduce gaseous divalent mercury in the exhaust gas to gaseous elemental mercury, ensuring that the gas exiting the third branch represents the total gaseous mercury concentration. The outlets of the first, second, and third branches are connected to the inlet of the elemental mercury analyzer 18, allowing for sequential detection of the concentrations of all three mercury forms using the same analyzer, reducing system costs. The wet chemical method for converting gaseous mercury forms is low-cost. The outlet of the elemental mercury analyzer 18 is connected to an adsorber, whose outlet is open to the atmosphere, adsorbing residual mercury in the exhaust gas to prevent secondary pollution. This system enables the testing of all three forms of mercury—elemental mercury, divalent mercury, and particulate mercury—in exhaust emissions from stationary pollution sources. The concentration of gaseous divalent mercury is obtained by subtracting the concentration of elemental mercury from the total gaseous mercury concentration, overcoming the technical difficulties of directly detecting divalent mercury.

[0023] In some embodiments, the diversion pipeline further includes an intake four-way valve 9 and an exhaust four-way valve 90. The intake four-way valve 9 is connected to the inlet of the first branch, the second branch and the third branch and the outlet of the filter 4. The exhaust four-way valve 90 is connected to the outlet of the first branch, the second branch and the third branch and the inlet of the elemental mercury analyzer 18.

[0024] Specifically, the diversion pipeline also includes an inlet four-way valve 9 and an exhaust four-way valve 90. The inlet four-way valve 9 is connected to the inlet of the first branch, the second branch, and the third branch, and the outlet of the filter 4. The exhaust four-way valve 90 is connected to the outlet of the first branch, the second branch, and the third branch, and the inlet of the elemental mercury analyzer 18. By switching between the inlet four-way valve 9 and the exhaust four-way valve 90, the timing control and independent detection of the gas in the three branches can be realized. The inlet four-way valve 9 controls the selective entry of exhaust gas, carrier gas, or backflush gas into the first branch, the second branch, or the third branch. The exhaust four-way valve 90 selectively introduces the outlet gas of the corresponding branch into the elemental mercury analyzer 18 according to the timing, avoiding cross-contamination between branches and affecting the test results. One set of elemental mercury analyzer 18 can complete the sequential measurement of gaseous elemental mercury concentration, gaseous total mercury concentration, and particulate mercury concentration in a time-sharing manner, reducing system hardware costs and improving detection efficiency and data reliability. The first branch is connected to the intake elemental mercury side 91 of the intake four-way valve 9; the second branch is connected to the intake particulate mercury side 93 of the intake four-way valve 9; the third branch is connected to the intake total mercury side 92 of the intake four-way valve 9; the first branch is connected to the exhaust elemental mercury side 94 of the exhaust four-way valve 90; the second branch is connected to the exhaust particulate mercury side 95 of the exhaust four-way valve 90; and the third branch is connected to the exhaust total mercury side 96 of the exhaust four-way valve 90. In some embodiments, the inlet of the divalent mercury absorption bottle 14 is connected to the divalent mercury absorption liquid storage tank 10, and the outlet of the divalent mercury absorption bottle 14 is used to discharge the first waste liquid 16.

[0025] Specifically, the inlet of the divalent mercury absorption bottle 14 is connected to the divalent mercury absorption liquid storage tank 10, and the outlet of the divalent mercury absorption bottle 14 is used to discharge the first waste liquid 16. Fresh absorption liquid is continuously replenished to the absorption bottle through the absorption liquid storage tank to maintain the stable absorption of gaseous divalent mercury by the absorption liquid and prevent the absorption liquid from becoming saturated and causing measurement deviation. At the same time, the first waste liquid 16 is discharged from the outlet of the absorption bottle. The waste liquid is automatically or periodically discharged to avoid the accumulation of absorption liquid in the bottle, which affects the airflow and reduces the maintenance frequency. It meets the needs of long-term online continuous monitoring of fixed pollution sources. The first delivery pump 12 can be set up to control the flow rate of the absorption liquid, so that the divalent mercury in the waste gas is fully absorbed while the elemental mercury is not affected, ensuring the accuracy of the concentration of pure elemental mercury represented by the gas at the outlet of the first branch.

[0026] In some embodiments, the inlet of the divalent mercury reduction bottle 15 is connected to the divalent mercury reduction liquid storage tank 11, and the outlet of the divalent mercury reduction bottle 15 is used to discharge the second waste liquid 17.

[0027] Specifically, the inlet of the mercury divalent reduction bottle 15 is connected to the mercury divalent reduction liquid storage tank 11, and the outlet of the mercury divalent reduction bottle 15 is used to discharge the second waste liquid 17. Fresh reducing liquid is continuously replenished to the reduction bottle through the reducing liquid storage tank to ensure a stable reducing liquid concentration, so that the gaseous mercury divalent in the waste gas is fully reduced to gaseous elemental mercury, avoiding a decrease in reduction efficiency after the reducing agent is consumed. The discharge of the second waste liquid 17 from the outlet of the reduction bottle can remove the by-products and waste liquid generated by the reaction in a timely manner, preventing the accumulation of liquid in the reduction bottle from affecting gas flow and reduction reaction, and extending the continuous working time of the reduction bottle. A second transfer pump 13 can be set up to control the flow rate of the reducing liquid, ensuring that the mercury divalent in the waste gas is completely converted so that the gas at the outlet of the third branch accurately represents the total concentration of gaseous mercury. It can also provide reliable data support for subsequent calculation of the concentration of gaseous mercury divalent by difference method, thereby meeting the automated operation requirements of long-term online monitoring of stationary pollution sources.

[0028] In some embodiments, a filter element and a temperature control heater 8 are arranged sequentially from top to bottom inside the filter 4, a backflush air intake 5 is provided at the top of the filter 4, and a backflush exhaust 6 is provided at the bottom of the filter 4.

[0029] Specifically, the filter element and the temperature control heater 8 are arranged sequentially from top to bottom inside the filter 4. The backflush air inlet 5 is set at the top of the filter 4, and the backflush exhaust 6 is set at the bottom of the filter 4. The filter element is used to intercept particulate mercury in the exhaust gas 1. The temperature control heater 8 controls the temperature of the filter 4 between 120°C and 180°C to avoid water vapor condensation in the flue gas, which would cause the filter element to become clogged. At the same time, the temperature is controlled below 180°C to prevent particulate mercury from being converted into gaseous mercury in advance during the filtration stage, thereby maintaining the original form of particulate mercury for subsequent backflush detection.

[0030] The temperature-controlled heater maintains the filter temperature above 500℃, which is also the precipitation temperature of particulate mercury. Upon heating, the particulate mercury on the filter element converts into gaseous mercury, providing a gaseous sample for subsequent particulate mercury detection. Backflush air intake 5 introduces backflush air from the top, and the airflow sweeps across the filter element in the opposite direction, stripping away deposited impurities. These impurities are then discharged through backflush exhaust 6 at the bottom, achieving filter element cleaning without manual disassembly, thus meeting the requirements for continuous automatic monitoring of stationary pollution sources. The combination of backflush air intake 5 and backflush exhaust 6 enables the filter element to self-clean. The temperature-controlled heater 8 stabilizes the operating temperature of the filter unit, reducing the interference of temperature fluctuations on the distribution of gaseous mercury and improving the system's measurement accuracy. The temperature-controlled heater maintains the filter temperature above 500℃, which is also the precipitation temperature of particulate mercury. Upon heating, the particulate mercury on the filter element converts into gaseous mercury, providing a gaseous sample for subsequent particulate mercury detection.

[0031] In some embodiments, an intake valve 2 is provided on the inlet pipe of the filter 4 to control the entry of exhaust gas 1.

[0032] Specifically, an inlet valve 2 is installed on the inlet pipe of filter 4 to control the entry of exhaust gas 1. When inlet valve 2 is open, exhaust gas is allowed to enter filter 4 for normal sampling and detection. When inlet valve 2 is closed, the exhaust gas source is cut off, providing isolation conditions for subsequent backflushing operations and system purging, preventing backflushing airflow from flowing back into the sampling pipe or fixed source flue, and ensuring that the backflushing air carrying impurities flows directionally through the backflushing exhaust 6. The filter system is cleaned by using inlet valve 2 in conjunction with backflushing operations, avoiding interference from impurities accumulated in the filter during continuous air intake. On the other hand, inlet valve 2 meets the control requirements of intermittent or continuous online monitoring of fixed pollution sources, improving the operational flexibility of the system.

[0033] In some embodiments, the carrier gas 3 is connected to the inlet pipe between the intake valve 2 and the filter 4, and the carrier gas 3 is connected to the carrier gas source.

[0034] Specifically, carrier gas 3 is connected to the inlet pipe between inlet valve 2 and filter 4, and to a carrier gas source. Before or after detection, inlet valve 2 is closed and carrier gas 3 is introduced. Carrier gas 3 flows through filter 4, the split pipe, and the elemental mercury analyzer 18, purging and cleaning the internal pipes of the system. This eliminates the memory effect caused by residual mercury vapor and improves the accuracy of subsequent detections. Carrier gas 3 can be introduced into the elemental mercury analyzer 18 for zero-point calibration, ensuring instrument baseline stability. Through the carrier gas 3 inlet located between inlet valve 2 and filter 4, carrier gas 3 can both purge filter 4 and downstream pipes in the forward direction and assist in the transfer of impurities from the filter element in backflushing mode. This prevents carrier gas 3 from directly entering the stationary source flue and causing dilution, thus leveraging the multiple functions of carrier gas 3 in system cleaning, calibration, and auxiliary detection, meeting the automatic calibration and maintenance needs of the online continuous monitoring system for stationary pollution sources. After carrier gas 3 is turned on, the gaseous mercury converted from particulate mercury can be sent to the converter 20 in the second branch for further conversion.

[0035] In some embodiments, the adsorber is filled with activated carbon or modified mercury adsorbent 19.

[0036] Specifically, residual mercury vapor that may not be fully detected in the outlet gas of the elemental mercury analyzer 18 can be captured by activated carbon or modified mercury adsorbent 19, which have a strong adsorption capacity for gaseous mercury. Activated carbon captures the mercury through physical adsorption, or modified mercury adsorbent 19 captures it through chemical complexation within the adsorber, ensuring that the mercury concentration in the exhaust gas released into the atmosphere is below environmental limits and preventing secondary pollution. Using modified mercury adsorbent 19, such as sulfur-loaded activated carbon or halide-impregnated activated carbon, can improve the adsorption efficiency for gaseous elemental mercury and divalent mercury, extend the adsorber replacement cycle, and reduce maintenance costs.

[0037] Embodiments of the present invention provide a method for monitoring elemental mercury, divalent mercury, and particulate mercury from stationary pollution sources, comprising the following steps: The exhaust gas 1 is sent into the filter 4. The gaseous mercury in the exhaust gas enters the first and third branches of the diversion pipeline respectively, while the particulate mercury in the exhaust gas is trapped on the filter element 7 of the filter 4; thus, the physical separation of gaseous mercury and particulate mercury is achieved, avoiding interference of particulate mercury on the detection of gaseous mercury.

[0038] When the exhaust gas passes through the first branch, the divalent mercury absorption bottle 14 on the first branch absorbs the gaseous divalent mercury in the exhaust gas. The outlet gas enters the elemental mercury analyzer 18 to measure the concentration of gaseous elemental mercury. By selectively removing divalent mercury through absorption, a pure elemental mercury signal is obtained. When the exhaust gas passes through the third branch, the divalent mercury reduction bottle 15 on the third branch reduces the gaseous divalent mercury in the exhaust gas to gaseous elemental mercury. The outlet gas enters the elemental mercury analyzer 18 to measure the concentration of total gaseous mercury. By utilizing reduction and conversion, the analyzer can respond to total gaseous mercury, solving the problem that divalent mercury cannot be directly detected. The air intake of the sealed filter 4 is stopped, and the filter 4 is heated to a higher temperature. The particulate mercury on the filter element 7 evaporates, and the carrier gas blows the mercury vapor into the second branch of the split pipeline. After passing through the converter 20 in the second branch, the particulate mercury is converted into gaseous elemental mercury. The gaseous elemental mercury enters the elemental mercury analyzer 18 to measure the concentration of particulate mercury. The online detection of particulate mercury is achieved by carrying it with the carrier gas and heating and converting it, thus overcoming the shortcomings of the detection of particulate mercury.

[0039] To calculate the concentration of gaseous divalent mercury, the difference between the total gaseous mercury concentration and elemental mercury is the concentration of gaseous divalent mercury. The outlet gas of the elemental mercury analyzer 18 is sent to the adsorber for adsorption treatment before being released into the atmosphere. This adsorption process removes residual mercury from the exhaust gas, preventing secondary pollution.

[0040] In some embodiments, before and / or after detection, carrier gas 3, placed between the sampling line and the filter 4, purges and cleans the split line, and / or performs zero-point calibration on the elemental mercury analyzer 18.

[0041] Specifically, by forward purging the entire gas path with carrier gas 3, residual mercury vapor and impurity gases in the pipeline are replaced and discharged, eliminating the interference of memory effect on subsequent detection results. This improves detection accuracy and repeatability. Carrier gas 3 is directly introduced into the elemental mercury analyzer 18 for zero-point calibration, ensuring the instrument baseline returns to the true zero point and avoiding measurement deviations caused by zero-point drift. The purging and cleaning operation of carrier gas 3 can be performed automatically on a regular basis without manual intervention.

[0042] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0043] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0044] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0045] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0046] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0047] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A monitoring system for elemental mercury, divalent mercury, and particulate mercury from stationary pollution sources, characterized in that, include: The system includes a filter, a distribution pipeline, a converter, and an elemental mercury analyzer. Exhaust gas passes through the filter and enters the distribution pipeline. The filter captures particulate mercury in the exhaust gas. The distribution pipeline includes a first branch, a second branch, and a third branch connected in parallel. A divalent mercury absorption bottle is installed on the first branch to absorb gaseous divalent mercury in the exhaust gas, resulting in gaseous elemental mercury at the outlet of the first branch. A converter is installed on the second branch to convert particulate mercury from the filter into gaseous elemental mercury. A divalent mercury reduction bottle is installed on the third branch to reduce gaseous divalent mercury in the exhaust gas back to gaseous elemental mercury. The outlets of the first, second, and third branches are connected to the inlet of the elemental mercury analyzer. The outlet of the elemental mercury analyzer is connected to an adsorber, and the outlet of the adsorber is open to the atmosphere.

2. The stationary pollution source elemental mercury, divalent mercury, and particulate mercury monitoring system according to claim 1, characterized in that, The diversion pipeline also includes an intake four-way valve and an exhaust four-way valve. The intake four-way valve is connected to the inlet of the first branch, the second branch and the third branch and the outlet of the filter. The exhaust four-way valve is connected to the outlet of the first branch, the second branch and the third branch and the inlet of the elemental mercury analyzer.

3. The stationary pollution source elemental mercury, divalent mercury, and particulate mercury monitoring system according to claim 1, characterized in that, The inlet of the divalent mercury absorption bottle is connected to the divalent mercury absorption liquid storage tank, and the outlet of the divalent mercury absorption bottle is used to discharge the first waste liquid.

4. The stationary pollution source elemental mercury, divalent mercury, and particulate mercury monitoring system according to claim 1, characterized in that, The inlet of the divalent mercury reduction bottle is connected to the divalent mercury reduction liquid storage tank, and the outlet of the divalent mercury reduction bottle is used to discharge the second waste liquid.

5. The stationary pollution source elemental mercury, divalent mercury, and particulate mercury monitoring system according to claim 1, characterized in that, The filter contains a filter element and a temperature-controlled heater arranged sequentially from top to bottom. The top of the filter has a backflush air intake, and the bottom of the filter has a backflush exhaust.

6. The monitoring system for elemental mercury, divalent mercury, and particulate mercury from stationary pollution sources according to claim 1, characterized in that, An inlet valve is installed on the inlet pipe of the filter to control the entry of exhaust gas.

7. The stationary pollution source elemental mercury, divalent mercury, and particulate mercury monitoring system according to claim 6, characterized in that, The carrier gas is connected to the inlet pipe between the air intake valve and the filter, and the carrier gas is connected to the carrier gas source.

8. The stationary pollution source elemental mercury, divalent mercury, and particulate mercury monitoring system according to claim 1, characterized in that, The adsorber is filled with activated carbon or modified mercury adsorbent.

9. A method for monitoring elemental mercury, divalent mercury, and particulate mercury from stationary pollution sources, utilizing the system as described in any one of claims 1-8, characterized in that, Includes the following steps: The exhaust gas is sent into the filter, and the gaseous mercury in the exhaust gas enters the first and third branches of the diversion pipeline respectively, while the particulate mercury in the exhaust gas is trapped on the filter element of the filter. When the exhaust gas passes through the first branch, the divalent mercury absorption bottle on the first branch absorbs the gaseous divalent mercury in the exhaust gas, and the outlet gas enters the elemental mercury analyzer to measure the concentration of gaseous elemental mercury; when the exhaust gas passes through the third branch, the divalent mercury reduction bottle on the third branch reduces the gaseous divalent mercury in the exhaust gas to gaseous elemental mercury, and the outlet gas enters the elemental mercury analyzer to measure the concentration of total gaseous mercury. The air intake of the sealed filter is stopped, and the filter is heated to increase its temperature. The particulate mercury on the filter element evaporates, and the carrier gas blows the mercury vapor into the second branch of the split pipeline. After passing through the converter in the second branch, the particulate mercury is converted into gaseous elemental mercury. The gaseous elemental mercury enters the elemental mercury analyzer to measure the concentration of particulate mercury. To calculate the concentration of gaseous divalent mercury, the difference between the total gaseous mercury concentration and elemental mercury is the concentration of gaseous divalent mercury. The outlet gas of the elemental mercury analyzer is sent to an adsorber for adsorption treatment before being released into the atmosphere.

10. The method for monitoring elemental mercury, divalent mercury, and particulate mercury from stationary pollution sources according to claim 9, characterized in that, Before and / or after the test, the carrier gas placed between the sampling line and the filter is used to purge and clean the split line, and / or to perform zero-point calibration on the elemental mercury analyzer.

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