JP2023017950A - Online gas analyzer, electric dust collector operation method and desulfurization column operation method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an online gas analyzer capable of online and successively analyzing concentration of a predetermined component in an unpurified coke oven gas.

SOLUTION: An online gas analyzer 1 comprises a sample gas sampling tube 20, a gas analyzing part 30, and extraction pipes 41, 42. The gas analyzing part 30 includes: a measuring pipe 31 having the central part to which one end 20b of the sample gas sampling tube 20 is connected, one end 31a to the vicinity of which the extraction pipe 41 is connected, and the other end 31b to the vicinity of which the extraction pipe 42 is connected; a light emitting part 32 that emits a laser beam; a light receiving part 33 that receives a laser beam; an analysis part 34 that analyzes concentration of a predetermined component in a sample gas S; and gas introduction parts 37, 38 that make an inert gas flow into the measuring pipe 31. Ends 35a, 36a of respective connection pipes 35, 36 have smaller diameters than the measuring pipe 31, and are inserted into the measuring pipe 31.

SELECTED DRAWING: Figure 2

COPYRIGHT: (C)2023,JPO&INPIT

Description

The present invention relates to an on-line gas analyzer, an electric precipitator operating method, and a desulfurization tower operating method.

Unrefined coke oven gas produced during the carbonization of coal to produce coke is a mixture of yellow-brown gas and water vapor. This unrefined coke oven gas includes hydrogen, hydrocarbons such as methane and ethane, and combustible gases such as carbon monoxide.

At the same time, unrefined coke oven gas also contains components such as carbon dioxide, nitrogen, ammonia, hydrogen sulfide, benzene, naphthalene dust, and tar mist. Therefore, when using coke oven gas as fuel gas, it is necessary to purify coke oven gas in order to reduce the environmental impact of nitrogen oxides, sulfur oxides, black smoke, etc. at the place of use and to prevent clogging of pipelines. There is Therefore, in general, coke oven gas refining equipment is installed to remove ammonia, hydrogen sulfide, benzene, naphthalene, and tar from unrefined coke oven gas to obtain refined coke oven gas.

FIG. 1 shows an example of coke oven gas refining equipment. The crude coke oven gas generated from the coke oven includes a primary cooler (PC), a naphthalene scrubber (NS), an electrostatic precipitator (EP), a desulfurization tower, an ammonium sulfate crystallizer (dehydrogenation device), a final cooler (FC), It is refined through each refining process in equipment such as a benzol scrubber (BS) and used as refined coke oven gas. In many of these facilities, depending on the component to be removed from the coke oven gas, the circulating liquid is brought into contact with the coke oven gas to absorb and remove the predetermined component, and the absorbed component is removed. The circulation is repeated such that the circulating liquid is regenerated and brought into contact with the coke oven gas again.

By the way, in operating these facilities, it is necessary to change the circulation amount of the circulating liquid that circulates the facilities, adjust the amount of chemicals such as catalysts added to the facilities, etc., in response to fluctuations in various components in the coke oven gas. operation is required. Therefore, it is necessary to appropriately analyze the components of the coke oven gas in the refining process.

However, unrefined coke oven gas contains a large amount of condensable mist such as tar and water, and dust such as sublimating naphthalene and coke powder. was difficult due to the frequent replacement of filters.

For this reason, on-line continuous component analysis of coke oven gas has hitherto only been possible to measure refined coke oven gas with less condensable mist and sublimation naphthalene. In this case, in the continuous measurement of the refined coke oven gas, the gas component after passing through each refining equipment is detected. There is a problem that the detection of is delayed.

Conventionally, in the online continuous component analysis of gases, component analysis is often performed by gas chromatography, but due to the principle of measurement, it is a batch process, and there is a drawback that time delay occurs mainly due to the presence of retention time. rice field.

Therefore, in order to detect fluctuations in the composition of coke oven gas being processed at each refining facility as close to the facility as possible, it is necessary to manually detect unrefined coke oven gas using detector tubes and portable measuring instruments. There was no choice but to perform continuous measurements. In this case, since it is economically unreasonable to allocate specialized personnel, the measurement must be performed at a frequency of once every 4 or 8 hours. However, the change cannot be detected in real time.

Therefore, in gas component analysis by such non-continuous measurement, the removal rate and concentration fluctuation of gas components in each refining process cannot be measured in real time. There was a problem of waste due to operation with excessive capacity.

Under these circumstances, it has been desired to measure a gas containing many impurities such as unrefined coke oven gas on-line and in real time.

Conventionally, as a device for analyzing the component concentration of a measurement target gas passing through a pipeline, a laser beam is irradiated to the measurement target gas through a connecting pipeline connected to the pipeline through which the measurement target gas flows, and the measurement target gas An apparatus is known that analyzes the concentration of a predetermined component based on the amount of absorption of laser light (see, for example, Patent Document 1).

Recently, improvements in semiconductor technology have made it possible to irradiate laser light of various wavelengths, and laser gas analyzers capable of analyzing various components have been provided. Therefore, the introduction of gas composition analysis using a semiconductor laser, which has the advantages of not requiring a filter and having little time delay, has increased.

However, when analyzing unrefined coke oven gas, condensable mist and naphthalene contained in the gas condense on the inner walls of the pipes and in the connecting pipes, blocking the optical path of the laser beam and preventing correct measurement. there was a case.

As an example of introducing such unrefined coke oven gas into an analyzer, condensable mist, naphthalene, and condensable mist, naphthalene, are collected by a sample gas collection line, which is prevented from condensation by heating, etc., a heated electric filter, and a heated cotton filter. An analyzer has been proposed in which the gas is analyzed after it has been cooled with a cooler after dust is removed (see, for example, Patent Document 2).

JP 2013-101067 A Japanese Patent Publication No. 2003-527602

However, in the analyzer described in Patent Document 2, since the coke oven gas is passed through an electric filter, an explosion may occur due to an increase in oxygen concentration due to a hole in the sample gas sampling pipe or the like. In addition, due to the risk of clogging the cotton filter and the size of the sample gas collection pipe and equipment, the passage time between the sampling point and the analyzer is long, resulting in delays in obtaining analysis results. I had a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-described problems, and an object thereof is to provide an on-line gas analysis capable of analyzing the concentration of a predetermined component in unrefined coke oven gas on-line and continuously. An object of the present invention is to propose an apparatus, an electric precipitator operating method and a desulfurization tower operating method using the on-line gas analyzer.

The present invention for solving the above problems is as follows.
[1] An online gas analyzer that analyzes the concentration of a predetermined component in unrefined coke oven gas online and continuously,
a sample gas sampling pipeline having one end connected to a coke oven gas pipeline for sampling a part of the coke oven gas from the coke oven gas pipeline as a sample gas;
a gas analysis unit that analyzes a predetermined component in the sample gas sampled from the sample gas sampling line;
a first extraction pipeline and a second extraction pipeline for extracting the sample gas from the gas analysis unit;
with
The gas analysis unit is
A measurement pipeline, the other end of the sample gas sampling pipeline is connected to the center of the measurement pipeline, and the first extraction pipeline is connected to the vicinity of one end of the measurement pipeline. a measurement conduit to which the second withdrawal conduit is connected near the other end of the measurement conduit, and
a light emitting unit connected to the one end of the measurement pipeline via a first connection pipeline and emitting laser light toward the other end of the measurement pipeline;
a light receiving unit connected to the other end of the measurement pipe through a second connecting pipe and receiving the laser light emitted from the light emitting unit;
an analysis unit that analyzes the concentration of a predetermined component in the sample gas from information on the laser light emitted from the light emitting unit and information on the laser light received by the light receiving unit;
a gas introduction part provided in the first connection pipeline and the second connection pipeline for allowing an inert gas to flow into the measurement pipeline;
has
The end portions of the first connecting pipeline and the second connecting pipeline on the side of the measuring pipeline have a diameter smaller than that of the measuring pipeline and are inserted into the measuring pipeline. gas analyzer.

[2] The online gas analyzer according to Claim 1, wherein the measurement pipeline has a cross-sectional area larger than that of the sample gas collection pipeline.

[3] The first extraction pipeline is connected to the measurement pipeline vertically below the end of the first connection pipeline on the measurement pipeline side, and the second extraction pipeline is connected to the measurement pipeline. The online gas analyzer according to the above [1] or [2], wherein the channel is connected to the measurement pipeline vertically below the end of the second connection pipeline on the measurement pipeline side.

[4] Condensates of the components contained in the sample gas are formed on the outer surfaces of the ends of the first and second connecting pipes on the measurement pipe line side in the first and second connecting pipes. The on-line gas analyzer according to any one of [1] to [3], further comprising a suppressing section that suppresses clogging of the second connecting pipeline.

[5] The online gas analyzer according to any one of [1] to [4], further comprising a heater that heats the sample gas flowing through the sample gas collection pipeline.

[6] The one end of the sample gas sampling pipeline in the on-line gas analyzer according to any one of [1] to [5] is connected to the entrance side or the exit side of an electric precipitator in a coke oven gas refining facility. , a part of the coke oven gas is sampled as a sample gas from the coke oven gas pipeline by the sample gas sampling pipeline, and the sample gas is circulated in the measurement pipeline while the light emitting unit emits a laser beam from, receives the laser beam by the light receiving unit, analyzes the concentration of oxygen in the sample gas by the analysis unit, and manages the operation of the electric precipitator based on the analysis result A method of operating an electric dust collector, characterized by:

[7] Connect the one end of the sample gas sampling pipeline in the online gas analyzer according to any one of [1] to [5] to the inlet side or the outlet side of a desulfurization tower in a coke oven gas purification facility. Then, a part of the coke oven gas is sampled as a sample gas from the coke oven gas pipeline by the sample gas sampling pipeline, and the sampled gas is circulated in the measurement pipeline, and a laser is emitted from the light emitting unit. Light is irradiated and the laser beam is received by the light receiving unit, the concentration of hydrogen sulfide in the sample gas is analyzed by the analysis unit, and based on the analysis result, the amount of catalyst added to the desulfurization tower, desulfurization A method of operating a desulfurization tower, comprising adjusting at least one of a liquid circulation rate, a regeneration air rate, and a spray position of the circulating liquid.

According to the present invention, it is possible to analyze the concentration of a predetermined component in raw coke oven gas on-line and continuously.

It is a figure which shows an example of coke oven gas refining equipment. It is a figure which shows a suitable example of the on-line gas analyzer by this invention. (a) A diagram for explaining the positional relationship between a connecting pipeline and an extraction pipeline, and (b) a diagram showing a connecting pipeline provided with a suppressing portion. FIG. 4 is a diagram showing variations in oxygen concentration in sample gas for invention examples and comparative examples. It is a figure explaining the process in a desulfurization tower.

(online gas analyzer)
Hereinafter, embodiments of the present invention will be described with reference to the drawings. FIG. 2 shows a preferred example of an on-line gas analyzer according to the invention. The online gas analyzer 1 shown in FIG. 2 is an online gas analyzer that continuously analyzes the concentrations of predetermined components (eg, oxygen and hydrogen sulfide) in unrefined coke oven gas. Here, "on-line" means that the device is always connected to the coke oven gas pipeline through which the coke oven gas flows and can continuously analyze the concentration of a predetermined component in the coke oven gas.

The on-line gas analyzer 1 shown in FIG. 42 ), an exhaust line 50 and an exhaust device 60 .

The sample gas sampling line 20 has one end 20a connected to the coke oven gas line 10 and the other end 20b connected to the gas analysis unit 30 (measurement line 31). A part of the unrefined (that is, in the refining process) coke oven gas flowing through the inside of the gas analyzer 10 is sampled as a sample gas S and introduced into the gas analysis section 30 (measurement pipe line 31).

When the temperature of the unrefined coke oven gas drops, condensable mist, naphthalene, etc. may condense as described above, causing problems such as clogging of pipelines. Such clogging of the pipeline can be suppressed by increasing the flow velocity of the gas flowing through the pipeline. It is preferable to raise the temperature of S. As such a heater 21, a steam heater, an electric heater, or the like can be used, and it can be installed around the sample gas sampling pipe line 20 and used.

Instead of installing the heater 21, a heat insulating material (not shown) is installed on the outer surface of at least a part of the pipeline from the sample gas sampling pipeline 20 to the discharge pipeline 50 described later, and the inside of the pipeline is A decrease in the temperature of the flowing sample gas S may be suppressed. Moreover, it is more preferable to perform both the installation of the heater 21 and the installation of the heat insulating material.

The temperature of the unrefined coke oven gas varies depending on the gas sampling location, but is generally about 20°C to 85°C. It is preferable to configure

The gas analysis unit 30 has a measurement pipe line 31, a light emitting unit 32, a light receiving unit 33, and an analysis unit 34, and analyzes a predetermined component (for example, , oxygen, and hydrogen sulfide).

The measurement pipeline 31 is a main pipeline for introducing the sample gas S thereinto and analyzing the concentration of a predetermined component in the sample gas S. As shown in FIG. The other end 20b of the sample gas collection line 20 is connected to the center of the measurement line 31. In the example shown in FIG. The connection is made at approximately 90° to the extending direction of the path 31 .

A first extraction pipeline 41 is connected near one end 31a of the measurement pipeline 31, and a second extraction pipeline 42 is connected near the other end 31b. are also connected so that their extending directions are substantially 90° with respect to the extending direction of the measurement pipe line 31 .

With such a configuration, when the sample gas S is introduced from the sample gas collection line 20 into the measurement line 31, the sample gas S flows from the central portion of the measurement line 31 toward both ends 31a and 31b. Therefore, the flow velocity of the sample gas S decreases. As a result, if there is a condensed mist-like component in the sample gas S, the flow velocity also decreases. Moreover, when the direction of the gas flow changes, the condensed mist-like components in the sample gas S separate from the gas, adhere to the inner wall of the measurement conduit 31, and flow along the inner wall. The concentration of the mist-like component in the sample gas S flowing inside decreases.

In this way, when the components of the unrefined coke oven gas are analyzed using a laser beam, the influence of the condensed mist-like components in the sample gas S flowing through the measurement pipe line 31, which causes disturbance, is reduced. Measurement accuracy can be improved.

In addition, as shown in FIG. 2, it is preferable that the cross-sectional area of the measurement pipeline 31 is larger than the cross-sectional area of the sample gas sampling pipeline 20 . As a result, the flow velocity of the sample gas S introduced into the measurement pipe line 31 through the sample gas collection pipe line 20 can be further reduced, thereby further reducing the influence of the condensed mist components that cause disturbance.

For example, by making the cross-sectional area of the measurement pipeline 31 ten times larger than the cross-sectional area of the sample gas collection pipeline 20, the flow velocity of the sample gas S introduced into the measurement pipeline 31 can be increased by 20%. can be reduced by more than a factor of one. As a result, if there is condensed mist-like components in the sample gas S, the flow velocity can be reduced to 1/20 or less, and the influence of the condensed mist-like components that cause disturbance can be further reduced.

The light emitting unit 32 is connected to one end 31a of the measurement pipeline 31 via a first connection pipeline 35 and emits laser light toward the other end 31b of the measurement pipeline 31 . A semiconductor laser or the like can be used as a laser light source that constitutes the light emitting unit 32 . In addition, the wavelength of the laser light can be set to a wavelength suitable for the component to be analyzed in the sample gas S. It is desirable to choose absorption lines that do not overlap with the absorption wavelength.

The light receiving unit 33 is connected to the other end 31b of the measurement pipe 31 via a second connecting pipe 36, and receives the laser light emitted by the light emitting unit 32 and passing through the sample gas S. The light receiving section 33 can be composed of a photodiode or the like.

The analysis unit 34 analyzes the concentration of a predetermined component (for example, oxygen and hydrogen sulfide) in the sample gas S from information on the laser light emitted from the light emitting unit 32 and information on the laser light received by the light receiving unit 33. . Specifically, the analysis unit 34 determines the concentration of a predetermined gas component from the absorption amount of the laser light emitted from the light emitting unit 32 and absorbed by the gas component present in the measurement pipe line 31. can be analyzed.

In the present invention, the ends 35a and 36a of the first connecting pipe 35 and the second connecting pipe 36 on the side of the measuring pipe 31 are located closer to the measuring pipe 31 than the measuring pipe 31, as shown in FIG. 3(a). It has a small diameter and is inserted into the measuring line 31 , and a part of the connecting lines 35 , 36 is arranged projecting into the measuring line 31 . As a result, mist components and naphthalene dust condensed on the side surfaces or end surfaces of the measurement pipe 31 are prevented from growing and accumulating on the ends 35a and 36a of the connecting pipes 35 and 36, thereby blocking the optical path of the laser. can be done.

In addition, as shown in FIG. 3B, suppressing portions 39 are provided on the outer surfaces of the ends 35a and 36a of the first connecting pipe 35 and the second connecting pipe 36 on the measurement pipe 31 side. preferably. As a result, the condensate of the components contained in the sample gas S is suppressed from moving along the outer surfaces of the connecting pipes 35 and 36 toward the end portions 35a and 36a, so that the end surfaces of the connecting pipes 35 and 36 are Occlusion can be further suppressed.

In addition, it is essential that each of the connecting pipes 35 and 36 is provided with gas introducing portions 37 and 38 for circulating the inert gas into the measurement pipe 31 . That is, the condensed mist-like components in the sample gas S flowing in the measurement pipe line 31 are very little during the continuous analysis for a long period of time, but It may condense on the surface of the light-receiving unit 33, which is a laser light detection device, and interfere with gas analysis.

Therefore, in the present invention, the connecting pipes 35 and 36 are arranged in front of the light emitting portion 32 and the light receiving portion 33, and the gas introducing portions 37 and 38 for introducing an inert gas are provided in the connecting pipes 35 and 36, thereby The active gas is caused to flow into the measurement conduit 31 via the connecting conduits 35 and 36, thereby suppressing condensation and adhesion of mist-like components on the surfaces of the light emitting section 32 and the light receiving section 33. FIG.

As the inert gas to be introduced into the measurement pipe line 31, a gas having low reactivity with the sample gas S, such as nitrogen gas or argon gas, can be used.

In order to prevent the sample gas S from flowing into the connecting pipes 35 and 36 and contaminating the light emitting part 32 and the light receiving part 33 with mist components and naphthalene dust, the inert gas is higher than that in the measuring pipe 31. A small amount of inert gas may be introduced so that it flows into the connecting pipes 35 and 36 under pressure. If the amount of inert gas introduced is too large, the sample gas S in the measurement pipe line 31 may be diluted and the concentration of the component to be measured may be analyzed low.

In principle, the inert gas introduced into the measurement conduit 31 should flow into the extraction conduits 41 and 42 as it is, and should not flow into the depth of the measurement conduit 31. A higher effect can be achieved by introducing an amount corresponding to the difference between the gas discharged from 31 to extraction lines 41 and 42 and the gas flowing from sample gas collection line 20 to measurement line 31. can.

More simply, the concentration of the component to be measured in the sample gas S in the sample gas collection line 20 is detected by a detection tube (not shown) while the concentration of the component to be measured is analyzed in the measurement line 31. and adjust the amount of the inert gas introduced so that the inert gas can be introduced to a concentration equivalent to that detected by the detector tube. In addition, in order to prevent condensed components in the sample gas S from condensing, the inert gas is preferably preheated before being introduced.

Extraction pipelines 41 and 42 are pipelines for extracting the sample gas S from the gas analysis unit 30 (measurement pipeline 31). On the other hand, the second extraction pipeline 42 is connected to the vicinity of the other end 31b of the measurement pipeline 31 . In the example shown in FIG. 2 , the extracting pipelines 41 and 42 are connected so that their extending directions are approximately 90° with respect to the extending direction of the measuring pipeline 31 .

As shown in FIGS. 3(a) and 3(b), the extraction pipelines 41 and 42 are connected to the measurement pipeline 31 vertically below the positions of the ends 35a and 36a of the connecting pipelines 35 and 36. It is preferable that As a result, the inert gas introduced from the gas inlets 37 and 38 can be rapidly exhausted from the measurement pipe 31, and the mist-like components, naphthalene dust, etc. condensed on the inner wall of the measurement pipe 31 can be removed. It can be discharged from extraction lines 41 and 42 .

Further, it is more preferable to install drains (not shown) for discharging condensed mist-like components, naphthalene dust, etc. in the discharge pipes 41 and 42 .

The two withdrawal lines 41 and 42 are connected singly or in combination (connected in the example of FIG. 2) to the discharge line 50, and the sample gas extracted from the withdrawal lines 41 and 42 is connected to the discharge line 50. S is discharged to discharge line 50 . An exhaust device 60 is arranged in the discharge line 50 to return the sample gas S discharged from the discharge lines 41 and 42 to the coke oven gas line 10 through which the coke oven gas flows, or to the outside. Ejected.

Any suitable exhaust device 60, such as a gas suction pump, can be used. In particular, as shown in FIG. 2, it is preferable to use an ejector that blows steam downstream of the discharge line 50 . As a result, it is possible to prevent the temperature of the sample gas S from lowering, and to prevent condensed components in the gas from condensing and sticking.

(How to operate an electric dust collector)
The method of operating an electric precipitator according to the present invention is such that one end 20a of the sample gas sampling pipe line 20 in the on-line gas analyzer 1 according to the present invention is connected to the entrance side or the exit side of the electric precipitator in the coke oven gas refining equipment. A part of the coke oven gas is sampled as a sample gas S from the coke oven gas pipeline 10 by the sample gas sampling pipeline 20 , and the sampled sample gas S is circulated in the measurement pipeline 31 while the light emitting unit 32 A laser beam is emitted from the light receiving unit 33, the oxygen concentration in the sample gas S is analyzed by the analysis unit 34, and the operation of the electric precipitator is managed based on the analysis result. Characterized by

One important purpose of gas component analysis in the coke oven gas refining facility shown in FIG. 1 is detection of oxygen concentration in an electrostatic precipitator (EP). In other words, in the coke oven gas refining equipment, the oxygen concentration in the coke oven gas decreases due to deterioration of the coke oven furnace body and dry mains, holes due to corrosion of the intake equipment, inflow of odor from the odor pipe, etc. can rise. Such an increase in oxygen concentration may cause abnormal combustion in the electrostatic precipitator, resulting in an explosion.

In this regard, in the conventional method, the analysis of the gas component concentration can be performed only after the benzol scrubber (BS) process in the coke oven gas purification facility shown in FIG. No change could be detected quickly.

On the other hand, according to the online gas analyzer 1 of the present invention, the sample gas sampling line 20 is connected to the inlet side or the outlet side of the electrostatic precipitator, and the oxygen concentration in the sample gas S is analyzed. , the fluctuation of the oxygen concentration in the electrostatic precipitator can be quickly detected, and the operation of the electrostatic precipitator can be promptly stopped when the oxygen concentration exceeds the allowable value.

(Method of operating desulfurization tower)
In the desulfurization tower operating method according to the present invention, one end 20a of the sample gas sampling pipe 20 in the online gas analyzer 1 according to the present invention is connected to the inlet side or the outlet side of the desulfurization tower in the coke oven gas purification facility, and the sample is A sample gas S is sampled from the coke oven gas pipeline 10 by the gas sampling pipeline 20, and while the sampled gas S is circulated in the measurement pipeline 31, a laser beam is emitted from the light emitting unit 32 and detected by the light receiving unit 33. A laser beam is received, the concentration of hydrogen sulfide in the sample gas S is analyzed by the analysis unit 34, and based on the analysis results, the amount of catalyst added to the desulfurization tower, the circulation amount of desulfurization liquid, the amount of regenerated air, and the circulation liquid are determined. It is characterized by adjusting at least one of the spray positions of (the circulating desulfurization liquid).

Another important purpose of gas component analysis in the coke oven gas refining facility shown in FIG. 1 is detection of hydrogen sulfide concentration in the desulfurization tower. That is, in the desulfurization tower of the coke oven gas refining equipment illustrated in FIG. It is brought into contact with a desulfurization liquid containing ammoniacal picric acid as a catalyst to absorb hydrogen sulfide in the desulfurization liquid, and the desulfurization liquid after absorption is led to a regeneration tower constituting a part of the desulfurization tower, and the regeneration tower Air and desulfurization liquid are brought into contact with each other in the air flow to oxidize hydrogen sulfide and separate solid sulfur to regenerate the catalyst. Then, the desulfurization liquid containing the regenerated catalyst is introduced again to the upper part of the absorption tower and sprayed from the spray, and the desulfurization liquid is circulated between the absorption tower and the regeneration tower. At this time, the concentration of hydrogen sulfide in the coke oven gas may increase depending on the amount of desulfurization liquid circulated and the regeneration status of the catalyst in the regeneration tower.

However, in the conventional gas analysis method, as described above, it was not possible to quickly detect the concentration fluctuation of hydrogen sulfide in the desulfurization tower.

On the other hand, according to the online gas analyzer 1 of the present invention, the sample gas sampling line 20 is connected to the inlet side or the outlet side of the desulfurization tower, and the concentration of hydrogen sulfide in the sample gas S is analyzed. , promptly detect fluctuations in the concentration of hydrogen sulfide in the desulfurization tower, and when the concentration of hydrogen sulfide rises, increase the amount of catalyst added to the desulfurization liquid, or circulate the desulfurization liquid with a desulfurization liquid pump. The concentration of hydrogen sulfide in the desulfurization tower can be adjusted to the allowable level by increasing the circulation amount of a certain desulfurization liquid, increasing the amount of regeneration air supplied to regenerate the catalyst in the regeneration tower to promote regeneration of the catalyst in the desulfurization liquid, etc. It can be managed so as not to exceed the value.

The amount of coke oven gas generated in the desulfurization tower varies depending on the operation of the coke oven. For example, it increases or decreases depending on the number of empty coke ovens due to coke oven repair or light charging due to deterioration of the oven wall. In addition, the concentration of hydrogen sulfide changes depending on the blend of high sulfur content coal used. That is, the load on the desulfurization tower is reduced during operation when the amount of coke produced is low and the concentration of hydrogen sulfide is low.

Coke oven gas and desulfurization liquid are cooled with seawater or ring water, and the desulfurization liquid temperature varies seasonally. For example, in winter when the temperature of the desulfurization liquid is low, the absorption efficiency is high, so the load on the desulfurization tower is reduced compared to summer.

From the above, the desulfurization tower load fluctuates depending on the operating conditions of the coke oven and changes in temperature, and low-load operation may be performed. At that time, it is possible to reduce the electric power consumption of the circulating liquid pump by reducing the circulation amount of the desulfurization liquid in the absorber or by lowering the position of the spray for spraying the desulfurization liquid.

(Invention example)
The concentration of oxygen in unrefined coke oven gas was measured using the online gas analyzer 1 shown in FIG. Specifically, one end 20a of the sample gas sampling pipe (diameter: 25A) 20 in the device 1 is connected between the electrostatic precipitator (EP) and the desulfurization tower of the coke oven gas purification facility shown in FIG. bottom. Then, the sample gas S is sampled from the coke oven gas pipeline 10 by the sample gas sampling pipeline 20 (pressure: 10 kPa, temperature: 85 ° C.), and the sample gas S is measured through the measurement pipeline (diameter: 80 A) 31. While flowing, a laser beam (light source: semiconductor laser, wavelength: 760 nm) was emitted from the light emitting unit 32, the laser beam was received by the light receiving unit 33, and the concentration of oxygen in the sample gas S was measured by the analyzing unit 34. . In the above measurement, nitrogen gas heated to 70° C. was introduced from the gas introduction parts 37 and 38 at a flow rate of 25 NL/min, respectively, and while steam was being supplied to the discharge pipe 50 (300 kPa), the exhaust device 60 It was performed while evacuating (suction flow rate: 200 L/min). The measured oxygen concentrations are shown in FIG.

(Comparative example)
The oxygen concentration in the sample gas S was measured in the same manner as in the invention example. However, one end 20a of the sample gas sampling line 20 was connected to the outlet side of the BS in the coke oven gas refining facility shown in FIG. Other conditions are all the same as the invention examples.

FIG. 4 shows the variation in oxygen concentration in the sample gas (ie unrefined coke oven gas) for the inventive and comparative examples. From FIG. 4, it can be seen that the oxygen concentration fluctuates relatively gently in the comparative example, while the oxygen concentration fluctuates sharply in the inventive example. This indicates that the oxygen concentration of coke oven gas can be analyzed with good sensitivity by the on-line gas analyzer of the present invention.

In addition, from FIG. 4, the time at which the corresponding oxygen concentration is detected is shifted by about 11 minutes between the invention example and the comparative example. can be detected quickly. In addition, it can be seen that the oxygen concentration corresponding to the invention example and the comparative example is 0.8% lower in the comparative example. This is probably because the detection of the oxygen concentration fluctuation was delayed in the comparative example compared to the invention example, and thus more oxygen was consumed by the regeneration reaction (NH ₄ SH+1/2O ₂ →NH ₄ OH+S) in the desulfurization tower.

INDUSTRIAL APPLICABILITY According to the present invention, it is possible to analyze components in unrefined coke oven gas on-line and continuously, and therefore it is useful in the steel industry.

1 online gas analyzer 10 coke oven gas pipeline 20 sample gas sampling pipeline 20a one end 20b of sample gas sampling pipeline other end 30 of sample gas sampling pipeline analysis section 31 measurement pipeline 31a one end 31b of measurement pipeline measurement tube Other end 32 of path Light emitting unit 33 Light receiving unit 34 Analyzing units 35, 36 Connecting pipelines 35a, 36a Connecting pipeline ends 37, 38 Gas introducing unit 39 Suppressing units 41, 42 Extraction pipeline 50 Exhaust pipeline 60 Exhaust Device

Claims (7)

An on-line gas analyzer for on-line and continuous analysis of the concentration of a predetermined component in unrefined coke oven gas, comprising:
a sample gas sampling pipeline arranged outside the coke oven gas pipeline, having one end connected to the coke oven gas pipeline, and sampling a part of the coke oven gas from the coke oven gas pipeline as a sample gas;
a gas analysis unit that analyzes a predetermined component in the sample gas sampled from the sample gas sampling line;
a first extraction pipeline and a second extraction pipeline for extracting the sample gas from the gas analysis unit;
with
The gas analysis unit is
A measurement pipeline, the other end of the sample gas sampling pipeline being connected to the center of the measurement pipeline only via a valve, and the first extraction pipeline near one end of the measurement pipeline. is connected, and the second extraction pipeline is connected near the other end of the measurement pipeline;
a light emitting unit connected to the one end of the measurement pipeline via a first connection pipeline and emitting laser light toward the other end of the measurement pipeline;
a light receiving unit connected to the other end of the measurement pipe through a second connecting pipe and receiving the laser light emitted from the light emitting unit;
an analysis unit that analyzes the concentration of a predetermined component in the sample gas from information on the laser light emitted from the light emitting unit and information on the laser light received by the light receiving unit;
a gas introduction part provided in the first connection pipeline and the second connection pipeline for allowing an inert gas to flow into the measurement pipeline;
has
The end portions of the first connecting pipeline and the second connecting pipeline on the side of the measuring pipeline have a diameter smaller than that of the measuring pipeline and are inserted into the measuring pipeline. gas analyzer. 2. The on-line gas analyzer of claim 1, wherein said measurement line has a larger cross-sectional area than said sample gas collection line. The first extraction pipeline is connected to the measurement pipeline vertically below the end of the first connection pipeline on the measurement pipeline side, and the second extraction pipeline is connected to the measurement pipeline. 3. The on-line gas analyzer according to claim 1, wherein the second connecting conduit is connected to the measuring conduit vertically below the end of the second connecting conduit on the side of the measuring conduit. Condensates of components contained in the sample gas are formed on the outer surfaces of the ends of the first and second connecting pipes on the side of the measuring pipe in the first and second connecting pipes. 4. The online gas analyzer according to any one of claims 1 to 3, further comprising a suppressor for suppressing clogging of the connecting pipeline. The online gas analyzer according to any one of claims 1 to 4, further comprising a heater that heats the sample gas flowing through the sample gas collection pipeline. The one end of the sample gas sampling pipeline in the online gas analyzer according to any one of claims 1 to 5 is connected to the inlet side or the outlet side of an electric precipitator in a coke oven gas purification facility, and the sample A part of the coke oven gas is sampled as a sample gas from the coke oven gas pipeline through the gas sampling pipeline, and a laser beam is irradiated from the light emitting unit while the sample gas thus sampled is circulated in the measurement pipeline. and receiving the laser beam by the light receiving unit, analyzing the concentration of oxygen in the sample gas by the analyzing unit, and managing the operation of the electric precipitator based on the analysis result. How to operate the dust collector. The one end of the sample gas sampling pipeline in the online gas analyzer according to any one of claims 1 to 5 is connected to the inlet side or the outlet side of a desulfurization tower in a coke oven gas refining facility, and the sample gas is sampled. A part of the coke oven gas is sampled as a sample gas from the coke oven gas pipeline by a pipeline, and the sample gas is circulated in the measurement pipeline, and a laser beam is irradiated from the light emitting unit to the above The laser beam is received by the light receiving unit, the concentration of hydrogen sulfide in the sample gas is analyzed by the analysis unit, and based on the analysis results, the amount of catalyst added to the desulfurization tower, the circulation amount of desulfurization liquid, and regeneration A method of operating a desulfurization tower, characterized by adjusting at least one of the amount of air and the spray position of the circulating liquid.

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