JP2007278836A - Method of analyzing mercury in exhaust gas, and device therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of analyzing mercury in exhaust gas and a device therefor capable of preventing function decline of a decomposition filler caused by adhesion of organic matter, and correcting drift of a zero value of the mercury concentration caused by the organic matter when performing atomic absorption spectrometry. <P>SOLUTION: Since a decomposition temperature is heightened furthermore than a vaporization temperature of the organic matter, when divalent mercury in exhaust gas is decomposed to metal mercury, function decline of the decomposition filler 16b caused by surface adhesion of the organic matter is prevented. Since the exhaust gas just before entering a light absorbing cell 21 is brought into contact with gold in a mercury remover 28 to remove mercury, and the exhaust gas including the organic matter is subjected to the atomic absorption spectrometry at a zero adjusting time, a correction effect of the drift of the zero value of the mercury concentration of an atomic absorption spectrophotometer 29 caused by the organic matter is acquired for a longer period than a conventional technology using a mercury remover 28 into which activated carbon is input. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method and apparatus for analyzing mercury in exhaust gas, and more specifically, a method for analyzing mercury in exhaust gas capable of continuously measuring and monitoring the concentration of mercury contained in exhaust gas from a garbage incineration plant, cement production facility, etc. Relates to the device.

In recent years, interest in trace elements in exhaust gas from waste incineration facilities and cement production facilities has increased. Among them, since mercury is highly volatile and toxic, emission regulations (Directive 2000/76 / EU: 50 μg / Nm ³ ) have been implemented in the EU and the United States. In September 2003, guidelines for mercury environmental standards (annual average 0.04 μg / Nm ³ or less) were issued in September 2003, and it is estimated that mercury emission standards will be established sooner or later.
The boiling point of metallic mercury (Hg ⁰ ) is about 360 ° C. For this reason, for example, most of mercury introduced into a combustion system of a garbage incineration plant such as a rotary kiln or a cement manufacturing facility is vaporized here, and is released from the chimney through the flue along with the combustion gas. Therefore, if mercury emission regulations are implemented, it is inevitable that there will be restrictions on the procurement of cement raw materials and the selection of industrial waste that is thrown into the rotary kiln from outside the system and incinerated.

Conventionally, for example, a mercury continuous measuring device described in Non-Patent Document 1 is known as a device for measuring mercury in exhaust gas. Next, with reference to FIG. 3, the mercury continuous measurement apparatus of Non-Patent Document 1 will be specifically described.
As shown in FIG. 3, according to the continuous mercury measuring apparatus 100, the exhaust gas containing mercury or organic matter is first introduced into the probe unit 102 provided with the first exhaust gas circulation pipe A1 by the suction force of the suction pump 101. Is done. In the probe unit 102, dust in the exhaust gas is removed by the dust filter 103. Thereafter, the exhaust gas is introduced into the decomposition reactor 104. Here, mercury in the exhaust gas comes into contact with the decomposition filler 104a in an atmosphere of about 200 ° C., and divalent mercury (Hg ²⁺ ) is decomposed into metallic mercury (Hg ⁰ ). Next, the exhaust gas is gas-liquid separated while passing through the gas-liquid separation path 105a of the gas-liquid separator 105, and further cooled to about 2 ° C. by the dehumidifying unit 106, thereby removing moisture in the exhaust gas. Next, the exhaust gas passes through the first membrane filter 107, and after the moisture is almost completely removed, the exhaust gas is guided from the probe unit 102 to the air cleaning unit 108 through the communication pipe 120.

In the air cleaning unit 108, the exhaust gas comes into contact with the potassium hydroxide solution, and SOx in the exhaust gas is removed. Thereafter, the exhaust gas is led out to the measurement unit 109 that measures the mercury concentration via the second exhaust gas circulation pipe A2.
In the measurement unit 109, the mist of the potassium hydroxide solution is first removed by passing through the second membrane filter 110. Next, the exhaust gas is supplied to the absorption cell 112 of the atomic absorption analyzer 111 that measures the mercury concentration. In the atomic absorption analyzer 111, the exhaust gas is irradiated with light (light rays in the ultraviolet region such as the mercury lamp 113), and the transmitted light is received by a phototube, thereby absorbing the amount of light of a specific wavelength (254 nm) of metallic mercury. Is detected continuously, and the concentration of metallic mercury contained in the exhaust gas is determined.
Reference numeral 114 in FIG. 3 indicates a carrier containing metallic mercury to the decomposition reactor 104 once a day in order to obtain a calibration curve used for obtaining the mercury concentration in the exhaust gas from the measured value during atomic absorption analysis. It is a mercury standard gas generator that supplies gas. Reference numeral 115 denotes a bypass pipe connected to a portion between the second membrane filter 110 and the light absorption cell 111 in the second exhaust gas circulation pipe A2 accommodated in the measurement unit 109, and 116 denotes a downstream part of the bypass pipe 115. And a second flow path switching valve provided at a communication portion between the second exhaust gas circulation pipe A2, 117 is a mercury removing device provided in the middle of the bypass pipe 115 and containing activated carbon 117a, and 118 is a flow rate controller.

  Further, in the mercury continuous measuring apparatus 100, for example, the mercury concentration 0 value by the light absorption cell 112 is adjusted once per hour. In this zero adjustment, the exhaust gas that has passed through the second membrane filter 110 is supplied to the mercury remover 117 containing the activated carbon 117 a by switching the flow path switching valve 116. Here, mercury and organic matter in the exhaust gas are adsorbed on the activated carbon 117a. Thereafter, the exhaust gas from which the metal mercury and organic substances have been removed is supplied to the light absorption cell 112, and the intensity (absorption amount) of light having the same wavelength as that of the metal mercury is measured. In Non-Patent Document 1, the measured value (concentration value) of this exhaust gas in which metallic mercury and organic matter do not exist is an adjustment value for zero adjustment. Based on this adjustment value, the mercury concentration 0 value by the light absorption cell 112 is adjusted.

In general, organic substances have light absorption characteristics over a wide wavelength range. Therefore, it also absorbs light having the absorption wavelength of metallic mercury. As a result, the light absorption obtained by the light absorption cell 112 is the sum of the light absorption of metallic mercury and the light absorption of organic matter. In the mercury removing device 117 of Non-Patent Document 1, activated carbon 117a is used as a mercury removing member. Therefore, since not only metallic mercury but also organic matter is adsorbed and removed by activated carbon 117a, the absorption value of the absorption wavelength of metallic mercury has no influence of metallic mercury and organic matter, and the obtained adjustment value (zero adjustment) The measured value at the time is almost zero.
Nihon Instruments Inc. Mercury Concentration Analyzer Catalog

However, the mercury continuous measuring apparatus 100 of Non-Patent Document 1 has the following drawbacks.
That is, (1) when divalent mercury in the exhaust gas is decomposed, the temperature in the decomposition reactor 104 is about 200 ° C., which is lower than the temperature at which certain organic substances are vaporized. Therefore, organic substances in the exhaust gas easily adhere to the surface of the decomposition filler 104a, and the decomposition function of the decomposition filler 104a is lowered.
(2) At the time of zero adjustment, when activated carbon was used, organic substances contained in the gas were also adsorbed because of the high adsorption power. In general, since organic substances have absorption characteristics over a wide range of wavelengths, the amount of absorption obtained by the absorption cell 112 is the sum of the amount of absorption of metallic mercury and the amount of absorption of organic substances. Therefore, the drift of mercury concentration 0 value (mercury concentration 0 point) has occurred with the change in the amount of organic matter in the exhaust gas.

This invention prevents adhesion of organic substances to the surface of the decomposition filler, prevents degradation of the function of the decomposition filler due to the adhesion of organic substances, and corrects drift of zero mercury concentration caused by organic substances during atomic absorption analysis. It is an object of the present invention to provide a method and apparatus for analyzing mercury in exhaust gas.
Further, the present invention provides a method and apparatus for analyzing mercury in exhaust gas, which prevents organic substances and mercury from adhering to the gas-liquid separation path and can reduce errors in the measured value of mercury concentration caused by these adhesions. The purpose is to provide.

  The invention according to claim 1 is a mercury that decomposes divalent mercury in the exhaust gas into metallic mercury by a decomposition filler while supplying the exhaust gas containing the organic material to the decomposition reactor and heating it above the vaporization temperature of the organic material. A gas separation process, a gas-liquid separation process for separating the exhaust gas decomposed in the mercury decomposition process through a gas-liquid separation channel, and an exhaust gas separated in the gas-liquid separation process for atomic absorption analysis. Mercury analysis step for introducing mercury into the light absorption cell and measuring the concentration of mercury in the exhaust gas, and introducing the exhaust gas immediately before being introduced into the light absorption cell into a mercury remover every time a predetermined time elapses. A mercury removal step for removing mercury in the exhaust gas as gold amalgam by bringing the gold in the vessel into contact with the exhaust gas, and the exhaust gas from which the mercury has been removed is guided to the absorption cell, and light having the same wavelength as mercury Measuring the strength of It obtains an adjustment value based on the adjustment value, a mercury analysis method in the exhaust gas and a zero adjustment step of adjusting the concentration of mercury 0 value by the absorption cell.

According to the first aspect of the present invention, since the temperature in the decomposition reactor is higher than the vaporization temperature of the organic matter, when the exhaust gas is supplied to the decomposition reactor, the organic matter in the exhaust gas is vaporized. For this reason, when divalent mercury in the exhaust gas is decomposed into metallic mercury, organic substances in the exhaust gas hardly adhere to the surface of the decomposition filler. As a result, it is possible to prevent the degradation of the function of the decomposition filler due to the adhesion of the organic matter.
Also, when adjusting the mercury concentration to zero, the exhaust gas immediately before being introduced into the absorption cell is introduced into a mercury remover, the exhaust gas is brought into contact with gold, and only the mercury in the exhaust gas is removed as gold amalgam, and the organic matter remains as it is. Leave in. Then, if the exhaust gas from which only mercury has been removed is guided to the absorption cell and the intensity of light having the same wavelength as that of mercury is measured, the intensity of light of a specific organic substance overlapping the wavelength of mercury can be measured. This measured value is obtained as an adjustment value for zero adjustment. Thereafter, based on the adjustment value, the mercury concentration is adjusted to zero by the absorption cell.
By zero adjustment in this way, the drift of the mercury concentration zero value of the atomic absorption analyzer due to organic matter (naturally occurring time-dependent measured values over time) is longer than in the case of the prior art using activated carbon for the mercury remover. (Transition) correction effect can be obtained.

The vaporization of the organic matter may be evaporation or sublimation and boiling by the transition of the organic matter from the solid phase (liquid phase) to the gas phase.
Examples of organic substances include chain hydrocarbons to polycyclic aromatic hydrocarbons.
The term “above the vaporization temperature of the organic substance” means, for example, 400 ° C. or more.

Examples of the exhaust gas include exhaust gas from a cement manufacturing facility and that from a waste incineration plant.
As a decomposition filler that can be decomposed even at a temperature higher than the vaporization temperature of the organic substance, for example, a “mixture of activated carbon and calcium oxide” described in JP-A-63-201552 can be used.
The timing for performing the zero adjustment is arbitrary, for example, every several hours or every several days.
Introducing the exhaust gas immediately before being introduced into the light absorption cell into the mercury remover means that the exhaust gas that has passed through the mercury remover is directly introduced into the light absorption cell.
The mercury removed in the mercury removing process is, for example, divalent mercury or metallic mercury. However, since the divalent mercury is previously decomposed into metallic mercury by the decomposition reactor, metallic mercury is mainly removed.

  The invention according to claim 2 is the method for analyzing mercury in exhaust gas according to claim 1, wherein the gas-liquid separation path is washed with water every predetermined time.

  According to the second aspect of the present invention, by washing the gas-liquid separation path with water every predetermined time, metallic mercury and organic matter adhering to the road wall of the gas-liquid separation path are washed away. As a result, it is possible to reduce an error in the measurement value of the mercury concentration due to the adhesion of organic substances and mercury to the gas-liquid separation path.

  According to a third aspect of the present invention, there is provided a decomposition reactor that decomposes divalent mercury in the exhaust gas into metallic mercury by a decomposition filler while heating the exhaust gas containing the organic material to a temperature higher than the vaporization temperature of the organic material, and the decomposition reaction A gas-liquid separator that separates the exhaust gas decomposed by the gas through a gas-liquid separation path, and an absorption for atomic absorption spectrometry that measures the concentration of mercury in the exhaust gas separated from the gas-liquid by the gas-liquid separator A zero adjustment unit that adjusts the mercury concentration by the absorption cell every time a predetermined time elapses, and the zero adjustment unit introduces the exhaust gas just before being introduced into the absorption cell, An apparatus for analyzing mercury in exhaust gas, comprising a mercury remover for contacting the exhaust gas with gold and removing mercury in the exhaust gas as gold amalgam.

  A fourth aspect of the present invention is the mercury analyzer for exhaust gas according to the third aspect, further comprising water washing means for washing the gas-liquid separation path.

According to the method for analyzing mercury in exhaust gas according to claim 1 of the present invention and the mercury analyzer for exhaust gas according to claim 3, since the temperature in the decomposition reactor is made higher than the vaporization temperature of the organic matter, When divalent mercury is decomposed into metallic mercury, organic substances in the exhaust gas hardly adhere to the surface of the decomposition filler. As a result, it is possible to prevent the degradation of the function of the decomposition filler due to the adhesion of the organic matter.
In addition, when adjusting the mercury concentration to zero, the exhaust gas immediately before being introduced into the absorption cell is brought into contact with the gold in the mercury remover to remove only the mercury, and the exhaust gas containing organic matter is analyzed by atomic absorption. The intensity is set as an adjustment value for zero adjustment, and the mercury concentration 0 value can be adjusted by the absorption cell based on the adjustment value. As a result, a drift correction effect of zero mercury concentration of the atomic absorption analyzer due to the organic substance can be obtained for a longer period than in the case of the prior art using activated carbon for the mercury remover.

  In particular, according to the inventions of claim 2 and claim 4, since the gas-liquid separation path is washed with water every predetermined time, measurement of mercury concentration caused by adhesion of organic matter and mercury to the gas-liquid separation path It is possible to reduce the occurrence of value errors.

  Examples of the present invention will be specifically described below. Here, an example of measuring the concentration of mercury contained in the exhaust gas from the electrostatic precipitator provided in the middle of the flue of the cement manufacturing facility will be described.

In FIG. 1, reference numeral 10 denotes a mercury analyzer in exhaust gas according to Embodiment 1 of the present invention. The mercury analyzer 10 in this exhaust gas receives exhaust gas from an electrostatic precipitator provided in the middle of a flue of a cement manufacturing facility. A probe unit 11 that is introduced and performs pretreatment for mercury concentration measurement on the exhaust gas, and a measurement unit 12 that measures the mercury concentration in the exhaust gas derived from the probe unit 11 are provided.
The probe unit 11 has a dust filter 15 for removing dust contained in the exhaust gas from the electrostatic precipitator in order from the upstream to the downstream of the first exhaust gas circulation pipe 14 piped in the large casing 13 for exterior, While the exhaust gas containing organic matter is heated to a temperature higher than the vaporization temperature of the organic matter, the decomposition reactor 16 decomposes the divalent mercury in the exhaust gas into metallic mercury by the decomposition filler 16b, and the exhaust gas decomposed by the decomposition reactor 16 is gasified. A gas-liquid separator 17 that performs gas-liquid separation through the liquid separation path 17a, and a dehumidifier that cools the exhaust gas separated by the gas-liquid separator 17 while passing through the dehumidification path 18a and removes moisture in the gas. Section 18, water washing means 19 for washing gas-liquid separation path 17 a and dehumidification path 18 a every predetermined time, and exhaust gas dehumidified by dehumidification section 18 is filtered to remove moisture in the exhaust gas. And a membrane filter 20 are sequentially disposed to completely remove.

The dust filter 15 is obtained by housing a filter material 15b in a capsule-shaped casing 15a.
The decomposition reactor 16 is provided in a capsule-shaped casing 16a with a decomposition filler 16b whose decomposition action does not decrease even at a high temperature of 400 ° C., for example, “activated carbon and calcium oxide described in JP-A-63-201552”. The mixture is filled with.
The gas-liquid separator 17 has a gas-liquid separation pipe 17b bent in a U shape as a main body, and an upstream pipe of the gas-liquid separation pipe 17b communicates with an inflow pipe 19a for distilled water (washing water) supplied from the water washing means (distilled water tank 19). Has been. Further, the material of the gas-liquid separation tube 17b is changed to Teflon (registered trademark) to which organic components hardly adhere.
The water washing means sucks distilled water stored in the distilled water tank 19 once an hour by a drain pump (not shown) and pumps it to the inflow pipe 19a. The U-shaped bent portion of the gas-liquid separation tube 17b communicates with a short horizontal drain tube 17c for discharging used distilled water to the outside of the tube. A space in the gas-liquid separation pipe 17b constitutes a gas-liquid separation path 17a.

The dehumidifying section 18 has a casing 18b that also serves as heat insulation for the electronic cooler as a main body, and a dehumidifying tube 18c having a substantially V-shape is built in the internal space. A downward short drain pipe 18e through which used distilled water is discharged is communicated with the V-shaped bent portion of the dehumidifying pipe 18c. The exhaust gas sent to the dehumidifying unit 18 is dehumidified by cooling the moisture in the gas, and the condensed moisture is discharged to the outside from the drain pipe 18e. Both drain pipes 17c and 18e are provided with on-off valves.
The membrane filter 20 is a membrane filter 20a made of, for example, nitrocellulose having a large number of micropores in a vertical disk-shaped casing having a vertical axis direction.

Next, the measuring unit 12 will be described in detail.
The measurement unit 12 is for atomic absorption analysis that measures the mercury concentration in the filtered exhaust gas in order from the upstream side to the downstream side of the second exhaust gas circulation pipe 14A piped in another large casing 13A for exterior use. An absorption cell 21, a flow rate controller 22, an exhaust gas suction pump 23 in the entire mercury analyzer in the exhaust gas, and a zero adjustment means 24 for adjusting the mercury concentration 0 value by the absorption cell 21 every time a predetermined time elapses. In order to obtain a calibration curve to be used when obtaining the mercury concentration in the exhaust gas from the measured value at the time of atomic absorption analysis, a mercury standard for supplying a predetermined amount of carrier gas containing metallic mercury to the decomposition reactor 16 at predetermined time intervals. And a gas generator 25.

The second exhaust gas circulation pipe 14 </ b> A is communicated with the first exhaust gas circulation pipe 14 by a communication pipe 31 arranged outside.
The zero adjustment means 24 includes a bypass pipe 26 provided upstream from the attachment position of the light absorption cell 21 in the second exhaust gas circulation pipe 14A, a downstream part of the bypass pipe 26, and the second exhaust gas circulation pipe 14A. By providing the flow path switching valve 27 disposed in the communicating portion and the middle part of the bypass pipe 26, the exhaust gas immediately before being introduced into the light absorption cell 21 is guided through the bypass pipe 26, and the exhaust gas is brought into contact with gold. And a mercury remover 28 for removing mercury contained therein as gold amalgam.

The absorption cell 21 is the actual measurement unit 12 in the atomic absorption analyzer 29. In the atomic absorption analyzer 29, the exhaust gas constantly supplied to the absorption cell 21 is irradiated with light in the ultraviolet region from the mercury lamp 30, and the transmitted light is received by the photoelectric tube. Thereby, the light absorption amount of the specific wavelength (254 nm) of metallic mercury is continuously detected, and the concentration of metallic mercury contained in the exhaust gas is obtained.
The mercury standard gas generator 25 obtains a calibration curve to be used when obtaining the mercury concentration in the exhaust gas from the measured value at the time of atomic absorption analysis, for example, once a day, for example, 60 μg / Nm ³ to the dust filter 15. Is a device that supplies a predetermined amount of carrier gas (air) containing metallic mercury.

Next, a method for analyzing mercury in exhaust gas using the mercury analyzer 10 in exhaust gas according to Embodiment 1 of the present invention will be described. The following series of operations is executed by control of a control device (not shown) of the mercury analyzer 10.
First, the exhaust gas from the electrostatic precipitator of the cement manufacturing facility is introduced into the dust filter 15 of the probe unit 11 by the suction force of the suction pump 23, and the dust in the exhaust gas is removed here. The exhaust gas from which the dust has been removed is sent to the decomposition reactor 16, where the divalent mercury in the exhaust gas is decomposed into metallic mercury by the decomposition filler 16a exposed to a high temperature atmosphere at 400 ° C. At this time, since the temperature in the cracking reactor 16 is 400 ° C., which exceeds the vaporization temperature of the polycyclic aromatic hydrocarbons, the organic matter in the cracking reactor 16 is gasified, and the surface of the particulate cracking filler 16a It is hard to adhere to. As a result, it is possible to prevent the degradation of the function of the decomposition filler 16a due to the adhesion of the organic matter.

The decomposed exhaust gas is passed through the gas-liquid separation path 17a of the gas-liquid separator 17, where it is gas-liquid separated. The liquid is discharged to the outside through the drain pipe 18e. On the other hand, the gas component is sent to the dehumidifying unit 18. In the dehumidifying part 18, the dehumidifying pipe 18 c cooled to 2 ° C. dehumidifies. The condensed moisture is discharged to the outside from the drain pipe 18e.
The exhaust gas after dehumidification is supplied to the membrane filter 20, and moisture (moisture) in the exhaust gas is almost completely removed by passing through the membrane filter 20a. The exhaust gas thus pretreated is supplied from the probe unit 11 to the measuring unit 12 through the communication pipe 31. Specifically, the exhaust gas after the pretreatment is constantly supplied to the light absorption cell 21. In the light absorption cell 21, the exhaust gas is irradiated with light in the ultraviolet region from the mercury lamp 30. The transmitted light is received by the phototube. Thereby, the absorption amount of the light of the specific wavelength (254 nm) of metallic mercury is continuously detected, and the concentration of metallic mercury contained in the exhaust gas is obtained.

Next, a method for adjusting the mercury concentration 0 value in the atomic absorption analyzer 29 will be described.
First, the flow path switching valve 27 is operated to guide the exhaust gas immediately before being introduced into the light absorption cell 21 to the bypass pipe 26. As a result, the exhaust gas is introduced into the mercury remover 28, where the exhaust gas comes into contact with gold, and the mercury in the exhaust gas is removed as gold amalgam. Moreover, the organic matter remains in the exhaust gas as it is.
The exhaust gas from which only metallic mercury has been removed in this way reaches the absorption cell 21 and performs the above-described absorption analysis. At that time, if the intensity of light having the same wavelength as that of metallic mercury is measured, the intensity of light of a specific organic substance overlapping the wavelength of metallic mercury is measured. This measured value is obtained as an adjustment value for zero adjustment. Thereafter, the control device adjusts the mercury concentration 0 value by the light absorption cell 21 based on the adjustment value. Specifically, the light intensity of the organic matter is subtracted from the wavelength portion of the metallic mercury that has been raised by the light intensity of the organic matter.

By performing zero adjustment in this way, it is possible to obtain a drift correction effect of the mercury concentration 0 value of the atomic absorption analyzer 29 caused by organic substances for a longer period than in the case of the prior art using activated carbon for the mercury remover 28.
For example, once a day, the supply of the exhaust gas is stopped, a carrier gas containing 60 μg / Nm ³ of metallic mercury is flowed from the mercury standard gas generator 25 to the dust filter 15, and the exhaust gas is detected from the measured value at the time of atomic absorption analysis. The calibration curve used to obtain the mercury concentration is corrected.
FIG. 2 is a graph showing the effectiveness of the result of measuring the mercury concentration in the exhaust gas using the mercury analyzer according to this example. The vertical axis shows the value obtained by dividing the measured mercury concentration value by the analyzer by the actual measurement value, and the horizontal axis shows the case of the conventional measuring device before modification and the case of the above embodiment. As shown in this graph, while the ratio between the measured value and the measured value by the conventional measuring device before remodeling is about 0.4, the measured value by the measuring device improved according to the above embodiment The result of the ratio between the value and the actual measurement value corresponding to approximately 1 and high accuracy is shown. In the measurement with the measurement device before the modification and the measurement device after the improvement, the exhaust gas from the electrostatic precipitator of the same cement production facility was used as the sample gas, and each was performed three times.

1 is an overall configuration diagram of a mercury analyzer in exhaust gas according to Embodiment 1 of the present invention. FIG. It is a graph which shows the value which remove | divided the instrument instruction | indication value by the mercury concentration actual value obtained by the mercury analyzer in the waste gas concerning Example 1 of this invention. It is a whole block diagram of the mercury analyzer in the waste gas concerning the conventional means.

Explanation of symbols

10 Mercury analyzer in exhaust gas,
16 cracking reactor,
16b decomposition filler,
17a gas-liquid separation path,
17 Gas-liquid separator,
21 Absorption cell,
19 Flushing means,
24 zero adjustment means,
28 Mercury remover.

Claims (4)

A mercury decomposition step of decomposing divalent mercury in the exhaust gas into metal mercury by a decomposition filler while supplying exhaust gas containing organic matter to a decomposition reactor and heating the organic matter to a vaporization temperature or higher;
A gas-liquid separation step of separating the exhaust gas decomposed in the mercury decomposition step through a gas-liquid separation path;
A mercury analysis step of introducing the exhaust gas separated in the gas-liquid separation step into an absorption cell for atomic absorption analysis and measuring the concentration of mercury in the exhaust gas;
Every time a predetermined time elapses, the exhaust gas immediately before being introduced into the absorption cell is introduced into a mercury remover, and the gold in the mercury remover is brought into contact with the exhaust gas, whereby the mercury in the exhaust gas is converted into gold. Mercury removal process to remove as amalgam,
The exhaust gas from which the mercury has been removed is guided to the light absorption cell, an adjustment value is obtained by measuring the intensity of light having the same wavelength as mercury, and the mercury concentration is adjusted to zero by the light absorption cell based on the adjustment value. A method for analyzing mercury in exhaust gas, comprising a zero adjustment step.   The method for analyzing mercury in exhaust gas according to claim 1, wherein the gas-liquid separation path is washed with water every predetermined time. A decomposition reactor that decomposes divalent mercury in the exhaust gas into metallic mercury by a decomposition filler while heating the exhaust gas containing the organic material to a temperature higher than the vaporization temperature of the organic material;
A gas-liquid separator for separating the exhaust gas decomposed by the decomposition reactor through a gas-liquid separation path;
An absorption cell for atomic absorption analysis for measuring the concentration of mercury in the exhaust gas gas-liquid separated by the gas-liquid separator;
Zero adjustment means for adjusting the mercury concentration 0 value by the light absorption cell each time a predetermined time elapses,
The zero adjustment means introduces the exhaust gas immediately before being introduced into the light absorption cell, contacts the exhaust gas with gold, and removes mercury in the exhaust gas as gold amalgam to analyze mercury in the exhaust gas apparatus.   The mercury analyzer for exhaust gas according to claim 3, further comprising a water washing means for washing the gas-liquid separation path.

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