JPH05312796A - Apparatus for semi-continuous measurement and monitoring of chlorobenzene as alternate index for dioxine in exhaust gas - Google Patents

Abstract

PURPOSE:To measure the exhaust concentration of dioxine by semi-continuous measurement of chlorobenzene in an incineration exhaust gas produced by incinerating general wastes and industrial wastes. CONSTITUTION:A concentration device 2 wherein a sample gas wherefrom coexistent water, dust and the like are removed by an exhaust gas pretreatment is passed through adsorber tubes 5 and 6 and thereby organic compounds such as chlorobenzene are adsorbed by the adsorber tubes 5 and 6, is provided. Moreover, a gas chromatograph 3 which separates and detects a plurality of organic substances such as the chlorobenzene desorbed by heating the adsorber tubes 5 and 6 and a data processing device 4 which determines a peak detected by the gas chromatograph 3, on the basis of a working curve prepared beforehand, and displays the chlorobenzene in an exhaust gas, are provided.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an indirect monitoring device for measuring the emission concentration of dioxins by semi-continuous measurement of chlorobenzenes in incinerator exhaust gas obtained by incinerating general waste and industrial waste. is there.

[0002]

2. Description of the Related Art When incinerating general waste or industrial waste, harmful dioxins are generated from an incinerator. At present, it is difficult to continuously measure dioxins, so carbon monoxide (CO) and organic compounds, which are said to have a relatively high correlation with the emission of dioxins, are measured. The concentration of dioxins is estimated.

A continuous carbon monoxide measuring instrument is commercially available for measuring the concentration of dioxins. In addition, as a device for measuring an organic compound, a measuring device for collecting and concentrating the organic compound with an adsorbent, desorbing the organic compound from the adsorbent and introducing it into a gas chromatograph for measurement is also commercially available. ..

[0004]

However, although carbon monoxide (CO) can be continuously measured, it is approximately 50 pp.
In the low concentration region of m or less, the correlation with dioxins is not good, and there is a problem that the usefulness as a substitute index is not recognized so much.

In addition, the measurement of organic compounds, especially chlorobenzenes, showed a correlation with dioxins even in a low concentration range of carbon monoxide of 50 ppm or less, and most of the loss due to water removal in exhaust gas pretreatment. It is a useful alternative indicator substance. However, there is a problem that continuous measurement is difficult because the concentration is generally very small.

The present invention has been made to solve the above problems, and an object of the present invention is to provide a measurement / monitoring device capable of semi-continuous measurement of chlorobenzenes in which a correlation is recognized in the low concentration region of dioxins.

[0007]

In order to solve the above-mentioned problems, according to the present invention, a sample gas from which coexisting moisture and dust have been removed by exhaust gas pretreatment is passed through an adsorption pipe to adsorb organic compounds such as chlorobenzenes. A concentration device that adsorbs to the tube, a gas chromatograph that separates and detects multiple organic substances such as chlorobenzenes that have been desorbed by heating the adsorption tube, and the peaks detected by the gas chromatograph are quantified from a calibration curve prepared in advance. And a data processing device for displaying chlorobenzenes in exhaust gas.

[0008]

With the above structure, the sample gas is injected into the concentrator and passed through the adsorption tube so that the organic compound in the sample gas is adsorbed by the adsorbent. The adsorption tube on which the organic compound is adsorbed is heated to desorb the organic compound such as chlorobenzene from the adsorbent, and at the same time, the desorbed organic compound is sent to the gas chromatograph. In a gas chromatograph, a plurality of organic compounds such as chlorobenzene are separated and detected by a detector. The data processor selects only the chlorobenzene compound from each peak detected by the gas chromatograph, quantifies it from the calibration curve prepared in advance, and displays the amount of chlorobenzenes in the exhaust gas. Then, the concentration of dioxin having a correlation is calculated from the detected concentration of chlorobenzene and displayed.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a configuration diagram showing an embodiment of a semi-continuous measurement and monitoring device for chlorobenzenes as an alternative index for dioxins in exhaust gas. This semi-continuous measuring and monitoring device
Suction device 1, concentrating device 2, and gas chromatograph 3
And a data processing device 4.

The suction device 1 is a device for sending the sample gas to the concentrating device 2, and is provided with a pump and a flow meter for sending the sample gas. The sample gas is a gas obtained by removing coexisting moisture and dust from the exhaust gas discharged from the incinerator by pretreatment.

As shown in FIG. 2, the concentrator 2 is equipped with two adsorption tubes 5 on one side and two adsorption tubes 6 on the other side, for adsorbing organic compounds in the sample gas, and used alternately. It is configured to be able to. The adsorption tubes 5 and 6 are made of stainless steel and have dimensions of an inner diameter of 3 mm and a length of 10 cm, and the adsorbents 7 and 8 are filled in 5 cm of them.
Polymer beads [Tenax (registered trademark) GC or TA] are used as the adsorbents 7 and 8. It should be noted that heaters 9 and 10 are provided adjacent to the adsorption tubes 5 and 6 so that the adsorption tubes 5 and 6 can be heated to desorb the organic compounds adsorbed on the adsorbents 7 and 8 and to perform purging. ing.

A first valve 11 is provided above the adsorption tubes 5 and 6, and a second valve 12 is provided further above the first valve 11 so that gases such as carrier gas, sample gas, and purge gas come in and out. Are in control. First valve 1
1 includes a sample gas inlet 13 for injecting a sample gas and a purge gas inlet 14 for injecting a purge gas for purifying the adsorption tubes 5, 6. The second valve 12 includes a carrier gas inlet 15 for injecting a carrier gas, a sample outlet 16 for sending the sample and the carrier gas adsorbed by the adsorbents 7 and 8 to the gas chromatograph 3 side, and a sample gas or a purge gas after adsorption is discharged. The sample / purge gas outlet 17 is provided.

The gas chromatograph 3 is equipped with a column for separating a mixture of organic substances such as chlorobenzenes desorbed by heating the adsorption tubes 5 and 6, and a detector for detecting each compound separated by the column. The detector uses an electron capture type detector or a photoionization detector.

The data processing device 4 is a device for processing the data output from the gas chromatograph 3, and selectively displays the concentration of chlorobenzenes in the exhaust gas. If necessary, calculate the dioxin concentration from the chlorobenzene concentration and display it.

Next, the operation of the above configuration will be described. The sample gas after removing coexisting water and dust by pretreatment is operated from the sample gas inlet 13 of the concentrator 2 by operating the suction device 1. The injected sample gas passes through the first valve 11 and one suction pipe 5, and then passes through the second valve 12 and is exhausted from the sample / purge gas outlet 17. The sample gas is passed through the adsorption tube 5 at a flow rate of 0.3 liter / min for 20 minutes, and the total amount is about 6 liters. In this way, the sample gas is passed through one of the adsorption tubes 5 for 20 minutes so that the organic compound is adsorbed by the adsorbent 7. After that, adsorption tube 5
The heater 9 is heated to about 250 ° C. to desorb the organic compounds of chlorobenzenes from the adsorbent 7, and at the same time, the carrier gas is introduced from the carrier gas inlet 15 into the first valve 1.
The organic compound that has flowed through the first and second valves 12 and has been desorbed is sent to the column of the gas chromatograph 3. The column separates a plurality of organic compounds such as chlorobenzenes, and the separated organic compounds are detected by a detector. The data processing device 4 selects only the chlorobenzene compound from each peak detected by the detector,
Quantify from the calibration curve prepared in advance and display the amount of chlorobenzenes in the exhaust gas.

The concentration of dioxins is roughly determined from the detected concentration of chlorobenzenes. FIG. 3 is a correlation diagram showing an example of the correlation between dioxins and chlorobenzenes in the exhaust gas emitted from the refuse incinerator. If the correlation between the concentration of dioxins and the concentration of chlorobenzenes is obtained beforehand by the installed incinerator,
After that, by measuring the chlorobenzene concentration,
It is possible to get an overview of the concentration level of dioxins in exhaust gas in a very short time. Then, the data processing device 4 displays the concentration of dioxins from the concentration of chlorobenzenes.

As described above, about 2 on the side of one adsorption tube 5
Analysis is performed for 0 minutes, and then one adsorption tube 5 is connected to the heater 9
Purge gas inlet 14 while heating at 300 ° C for 30 minutes
Nitrogen gas is aerated from above to purge and perform cooling for 10 minutes before preparing for the next measurement. In this way, while purging on one adsorption pipe 5 side, chlorobenzenes are measured on the other adsorption pipe 6 side, and the measurement is performed semi-continuously once a hour while repeating each other. To do.

[0018]

As described above, according to the present invention, the concentration of chlorobenzenes, which has a correlation with dioxins in the low concentration region, is semi-continuously measured, and the emission concentration of dioxins in the low concentration region is measured. Indirect monitoring of

[Brief description of drawings]

FIG. 1 is a configuration diagram of a semi-continuous measurement and monitoring device of chlorobenzenes as an alternative index of dioxins in exhaust gas in one embodiment of the present invention.

FIG. 2 is a configuration diagram of a concentrating device of the monitoring device of the present invention.

FIG. 3 is a correlation diagram between the concentration of chlorobenzenes and the concentration of dioxins.

[Explanation of symbols]

 2 Concentrator 3 Gas chromatograph 4 Data processor 5 One adsorption tube 6 Other adsorption tube 7 Adsorbent 8 Adsorbent 9 Heater 11 First valve 12 Second valve

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Yutaka Sakaigawa 1-24-47 Shikitsuhigashi, Naniwa-ku, Osaka City, Osaka Prefecture Kubota Corporation

Claims (1)

[Claims] 1. A concentrator for adsorbing an organic compound such as chlorobenzene to the adsorption tube by ventilating the adsorption gas with a sample gas from which coexisting water and dust have been removed by exhaust gas pretreatment, and degassing by heating the adsorption tube. It was equipped with a gas chromatograph that separates and detects multiple organic substances such as chlorobenzenes that have been separated, and a data processor that displays the chlorobenzenes in the exhaust gas by quantifying the peaks detected by the gas chromatograph from a calibration curve that was created in advance. Semi-continuous measurement and monitoring device for chlorobenzenes as an alternative index for dioxins in exhaust gas.