JP3322420B2 - Automatic gas sampling method and automatic gas analysis method - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention continuously and automatically analyzes compounds that are easily dissolved in water, such as ammonia and hydrogen chloride in exhaust gas, and compounds that are easily adsorbed in a sampling line, on site. The present invention relates to an automatic gas sampling method and an automatic gas analysis method that can be performed.

[0002]

2. Description of the Related Art Conventionally, gas components in exhaust gas have been analyzed by taking a sample at the site and returning it to an analysis room for analysis by various analytical methods, or by installing a continuous analyzer comprising a sensor and a recorder at the site. Installation and monitoring methods have been adopted. Compounds in which the component to be analyzed is hardly soluble in water, such as carbon monoxide and nitric oxide, can be analyzed by the above continuous analyzer, but are easily dissolved in water, such as ammonia and hydrogen chloride. Compounds and compounds that are easily adsorbed in the sampling line may be condensed in the sampling line due to a decrease in the temperature of the sample gas, or may be adsorbed to cause a negative error in the measured value. It is difficult. Therefore, the absorption liquid that has absorbed the component gas to be analyzed was taken back to the analysis room for analysis.

On the other hand, liquid chromatographs such as high-performance liquid chromatographs and ion chromatographs have the characteristic that multiple components in a liquid can be simultaneously analyzed with high sensitivity in a short time by injecting a single sample. In particular, ion chromatography for inorganic components can easily analyze low-concentration cations or anions in a short time which is complicated and takes a long time by other analysis methods. A method has been used in which a gas component such as SO _X ) is absorbed in an absorbing solution and analyzed by ion chromatography.

[0004]

However, since an analyzer such as an ion chromatograph is for a liquid, it is necessary to absorb an analytical component in a gas into an absorbing solution. It could not be analyzed by the device and could not be used as an on-site automatic gas analyzer. Also, even in the field, the distance between the gas sampling unit and the analyzer is often very long, and when analyzing components that are easily dissolved in water, such as ammonia and hydrogen chloride, and components that are easily adsorbed in the sampling line, In addition, there is a problem that aggregation and adsorption in the gas sampling line are large, and the concentration cannot be accurately measured. Therefore, conventionally, it has been necessary to go to the site and collect an analysis sample every time measurement is performed. In addition, collection of an analytical sample on site requires skill, involves many risk factors, and requires a great deal of labor. In addition, the analysis of the components in the absorbing solution is complicated and requires a long time, which has been a great limitation when used as management data.

Therefore, the present invention solves the above-mentioned problems,
An object of the present invention is to provide an automatic gas sampling method and an automatic gas analysis method that can reliably collect a condensable and adsorptive gas component and can perform automatic analysis quickly.

[0006]

According to the present invention, there is provided (1) a method in which, after a gas sampling tube is almost heated to the temperature of a gas to be analyzed, the gas to be analyzed is sucked into the gas sampling tube and the inside of the gas sampling tube is in an adsorption equilibrium state. (2) a step of sucking the absorption liquid into the gas absorption bottle to a predetermined level; and (3) an analysis via the gas sampling pipe, the gas / absorption liquid introduction pipe, and the gas absorption bottle. A sampling step of sucking a predetermined amount of the target gas; (4) a step of cleaning the gas / absorbent liquid introduction pipe with a predetermined amount of the absorbing liquid and collecting the same in the gas absorption bin; Transferring the liquid to the analyzer as an analysis sample; and (6) a step of injecting the absorption liquid in the gas absorption bottle as an analysis sample into a liquid chromatograph for analysis. Characterized by having It is an automated gas analysis how to.

[0007]

According to the method of the present invention, the gas sampling tube is heated and a large amount of gas is caused to flow through the gas sampling tube to guide the gas sampling tube to adsorption equilibrium in a short time. After the end of sampling, a predetermined amount of the absorbing liquid is passed through the gas introduction pipe connecting the gas sampling pipe and the absorption bottle, and the analyte component condensed and adsorbed on the gas introduction pipe at the time of sampling. Was washed out with an absorbing solution and collected in a gas absorbing bottle, whereby the component to be analyzed could be reliably captured in the absorbing solution, and the analysis accuracy could be improved. In addition, by employing the above-described gas sampling method, it is possible to effectively use a liquid chromatograph such as an ion chromatograph, thereby facilitating gas sampling and automatic analysis on site.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of an automatic gas sampling method and an automatic gas analysis method according to the present invention will be described below in detail with reference to FIGS. Embodiment 1 FIG. 1 is a conceptual diagram of an apparatus for automatically collecting a component gas to be analyzed from flue gas. The main components of the apparatus are a gas sampling pipe A provided with a heater 9 and an absorbent storage tank 1.
And a gas / absorbent introduction pipe B for connecting the sample and the absorption bottle 3, a drying tower 4, a gas meter 5, and an absorption sample liquid receiving tank 2. The procedure of gas sampling is as follows.

[Heating of sampling line] Solenoid valve S-
1 is closed, the pump P-1 is operated to flow the exhaust gas to the gas sampling pipe A, the heater 9 is turned on, and the gas sampling pipe A is heated to almost the same temperature as the exhaust gas temperature. The inside of the tube A is kept in an adsorption equilibrium state. [Suction of the absorbing liquid into the absorbing bottle] Simultaneously with the heating of the sampling line, the solenoid valves S-2 and S-6 are opened,
Solenoid valves S-1, S-3, S-4, S-5, S-7, S-
8 is closed, the suction pump P-4 is operated, and the absorption bottle 3 is moved from the absorption liquid storage tank 1 through the gas / absorption liquid introduction pipe B.
Then, the absorbing liquid is sucked and filled up to the liquid level L1 of the absorbing bottle 3.

[Gas sampling] Next, the solenoid valve S-
1, S-4 are opened and the solenoid valves S-2, S-3, S-
With the 5, 5, S-6, S-7 and S-8 closed, the suction pump P-2 is operated to suck the sample gas into the absorption bottle 3. After the gas from the absorption bottle 3 is dried through the drying tower 4, the gas flows into the gas meter 5 to measure the gas, and the gas set in the absorption gas amount counter 6 is sucked. Note that a needle valve 8 is attached to the above gas sampling line.

[Cleaning of Gas and Absorbent Inlet Pipes] After gas sampling, the solenoid valves S-2 and S-6 are opened, and the solenoid valves S-1, S-3, S-4, S-5 and S-5 are opened. S-7,
With S-8 closed, operate the suction pump P-4,
The absorption liquid flows from the absorption liquid storage tank 1 to the gas / absorption liquid introduction pipe B, and the components to be analyzed condensed and adsorbed in the introduction pipe B are washed out and collected in the absorption bottle 3. The absorption liquid is allowed to flow through the introduction pipe B until the liquid level of the absorption bottle 3 reaches L2.
Analyte components at the time of gas sampling are reliably captured in the absorbing solution.

[Transfer of Absorbing Sample Solution] Solenoid valves S-3, S-
5 is opened, and the solenoid valves S-1, S-2, S-4, S-
6, S-7 and S-8 are closed, and pressurizing pump P-3
Is operated, and the absorption sample liquid in the absorption bottle 3 is transferred to the absorption sample receiving tank 2. [Extraction of Absorbing Sample Solution to Outside of System] The absorbing sample solution in the absorbing sample receiving tank 2 is periodically opened with the use of a timer by opening the electromagnetic valve 8 and extracted out of the system for use as an analysis sample. By repeating the above operation, gas can be automatically collected.

Embodiment 2 FIG. 2 is a conceptual diagram of an apparatus for automatically analyzing a component gas to be analyzed from flue gas. This apparatus has an ion chromatograph 11 connected to the absorption sample liquid receiving tank 2 of the apparatus shown in FIG.
Is the same as After the absorption sample solution is collected in the absorption sample receiving tank 2 by the above-described gas sampling procedure, the pump P-5 is operated, and the ion chromatograph 11 is
The sample is injected into the sample and analyzed. The analysis result is obtained by taking the data of the suction gas amount counter 6 and the temperature of the gas meter 5 into the data processing device 12, calculating the concentration of the analysis target component, and outputting the result.

[0014]

According to the present invention, by adopting the above structure, a gas sampling pipe directly connected to a flue or the like is maintained in an adsorption equilibrium state, and a gas / absorbing liquid introduction pipe extending from the gas sampling pipe to an absorption bottle is provided. Analyte components condensed and adsorbed on the surface are washed out with the absorbing solution and collected in the absorption bottle, so that the analyte components can be reliably captured in the absorbing solution and the liquid chromatograph such as an in-chromatograph can be used effectively. And facilitated on-site automatic gas sampling and automatic gas analysis.

[Brief description of the drawings]

FIG. 1 is a conceptual diagram of an automatic gas sampling apparatus for carrying out a method of the present invention.

FIG. 2 is a conceptual diagram of an automatic gas analyzer for performing the method of the present invention.

──────────────────────────────────────────────────続 き Continuing on the front page (72) Atsushi Morii 1-1, Akunoura, Nagasaki, Nagasaki Prefecture Inside Nagasaki Shipyard, Mitsubishi Heavy Industries, Ltd. No. 48 in Lab-Tech Co., Ltd. (56) References JP-A-3-224627 (JP, A) JP-A-61-155764 (JP, U) JP-B-2-6018 (JP, B2) JP-B-2-45793 (JP, Y2) (58) Field surveyed (Int. Cl. ⁷ , DB name) G01N 1/00-1/44 G01N 30/00-30/96 JICST file (JOIS)

Claims (2)

(57) [Claims] (1) a step of substantially heating a gas sampling tube to a temperature of a gas to be analyzed and then sucking the gas to be analyzed into the gas sampling tube to maintain the gas sampling tube in an adsorption equilibrium state;
(2) a step of sucking the absorption liquid into the gas absorption bottle to a predetermined level; and (3) a suction of a predetermined amount of the gas to be analyzed through the gas sampling pipe, the gas / absorption liquid introduction pipe, and the gas absorption bottle. Sampling step, (4) washing the gas / absorbing liquid introduction pipe with a predetermined amount of absorbing liquid, and collecting it in the gas absorbing bottle, and (5) analyzing the absorbing liquid in the gas absorbing bottle as an analysis sample. Transferring the gas to an apparatus. 2. (1) After substantially heating the gas sampling tube to the temperature of the gas to be analyzed, sucking the gas to be analyzed into the gas sampling tube to maintain the inside of the gas sampling tube in an adsorption equilibrium state;
(2) a step of sucking the absorption liquid into the gas absorption bottle to a predetermined level; and (3) a suction of a predetermined amount of the gas to be analyzed through the gas sampling pipe, the gas / absorption liquid introduction pipe, and the gas absorption bottle. (4) a step of washing the gas / absorbent liquid introducing pipe with a predetermined amount of the absorbing liquid and collecting the gas / absorbent liquid in the gas absorbing bottle; And injecting into a chromatograph for analysis.