JPH0713633B2 - Total organic carbon meter - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a regeneration treatment or activation treatment means for an oxidation catalyst in the all-carbon combustion part of an all-organic carbon meter and / or a reaction agent in the inorganic carbon reaction part. The present invention relates to an apparatus for measuring total organic carbon.

[Prior Art] The total organic carbon meter is mainly used for measuring total organic carbon in water.
Carbon, hereinafter referred to as TOC) is a measuring device for quantitatively measuring. The basic principle is that the sample is completely combusted in an oxidation catalyst to find the total carbon concentration (Ct) as carbon dioxide, and the inorganic carbon concentration (Ci) in the sample is separately determined in the inorganic carbon reaction part.
And Ci are quantitatively measured separately by a non-dispersive infrared spectrometer, and the quantitative value of TOC is calculated using the following formula.

TOC = Ct-Ci ……… Formula [I] TOC has traditionally been used as an essential measuring means for water quality control of water and sewage, groundwater, rivers, etc. It is a very important measurement tool for water quality control of electronic devices such as pure water and precision industry. These industrial applications require TOC water quality control on the order of ppb (ppb is 1/1000 of ppm).

By the way, the TOC meter is composed of at least a carrier gas supply section, a total carbon combustion section (TC combustion section), an inorganic carbon reaction section (IC reaction section), a dehumidification section, and a carbon dioxide detection section. Then, platinum, cobalt oxide, palladium, chromate or the like is used as an oxidation catalyst in the TC combustion section, and a reaction agent such as an inorganic acid or an ion exchange resin is used in the IC reaction section.

[Problems to be Solved by the Invention] However, when the conventional TOC meter is used for a certain period of time, the above-mentioned TC oxidation catalyst or IC reactant deteriorates. However, there is a problem that the replacement and the reproduction process must be performed manually. In other words, TC burner and IC
The troublesome work of disassembling the reaction part, replacing the catalyst and the reactant inside, and reassembling was necessary.

In order to solve the above-mentioned problems of the prior art, the present invention provides a means for injecting an inorganic acid to the TC combustion section, and / or the IC reaction section, and a means for integrating the sample injection amount. Provide a TOC meter that is injected with an inorganic acid when it exceeds a certain value, and can perform regeneration or activation treatment of TC oxidation catalyst or IC reactant manually or automatically if the operator specifies. To do.

Furthermore, the cumulative injection amount is calculated from the sample injection amount and the number of times, and based on this, the timing of the regeneration process is predicted in advance,
Provided is a TOC meter capable of automatically performing a regeneration process or an activation process of an IC reactive agent.

[Means for Solving the Problems] In order to achieve the above object, the present invention has the following constitution.

That is, the present invention provides a total organic carbon meter including at least a carrier gas supply unit, a total carbon combustion unit using an oxidation catalyst, an inorganic carbon reaction unit using an inorganic carbon reactant, a dehumidification unit, and a carbon dioxide gas detection unit. A means for obtaining an integrated amount of inorganic carbon from the concentration of inorganic carbon detected by the carbon dioxide detection part; and a means for injecting an inorganic acid into the all-carbon combustion part when the integrated amount of the inorganic carbon exceeds a certain value. , And the total carbon combustion section and the inorganic carbon reaction section are connected in series.

A feature of the present invention is a means for injecting an inorganic acid for regeneration or activation treatment of a TC oxidation catalyst and / or an IC reaction agent, and an injection for the TC combustion section and / or the IC reaction section. The TOC is equipped with a means for calculating the total injection amount by integrating the amount of injected sample and the number of injections, and for injecting the inorganic acid when the total injection amount of the sample exceeds a certain position.
It is in the total. As a result, the TC oxidation catalyst and / or the IC reactant can be regenerated or activated automatically or manually. If it can be automatically performed, the regeneration processing can be automatically performed without stopping the supply of the carrier gas, so that the regeneration processing can be performed quickly and accurately without the baseline being disturbed.

In the present invention, the inorganic acid injected into the TC combustion section and / or the IC reaction section may be any inorganic acid such as hydrochloric acid, phosphoric acid, nitric acid, sulfuric acid, etc. Is hydrochloric acid. It is preferable to use the inorganic acid as an aqueous solution in order to protect the measurement system. The dilution ratio in the case of making an aqueous solution can be arbitrary. The means for injecting the inorganic acid preferably comprises an inorganic acid aqueous solution storage container, an inorganic acid supply line, and an inorganic acid transfer means.

In the present invention, the carrier gas supply unit preferably includes, for example, a pressure reducing valve, a pressure gauge, a flow controller, and a flow meter. This is because pure gas is quantitatively sent to the measurement system. As the carrier gas, high-purity air or the like can be used.

Next, a precious metal such as platinum, cobalt oxide, palladium, chromate or the like can be used as an oxidation catalyst in the TC combustion section. Of these, when a precious metal catalyst such as platinum is used, in addition to regeneration treatment by injecting an inorganic acid,
It is convenient because the catalyst capacity activation treatment can be performed. TC combustion section
A temperature of about 400 ° C to 950 ° C is preferable.

Next, as the IC reaction part, any reaction device that can convert inorganic carbon (carbonic acid carbon) into carbon dioxide and can be regenerated with an inorganic acid can be used. As an example of the reaction agent used in the IC reaction section, an inorganic acid such as hydrochloric acid, phosphoric acid, nitric acid, or sulfuric acid may be used as an aqueous solution, a reproducible solid acid, a strongly acidic ion exchange resin, or the like. It may be a reactive agent. As a preferred IC reactant, a strongly acidic ion exchange resin is dispersed in an aqueous solution and gas is bubbled. This is because a so-called fluidized bed reaction can be performed and the active surface of the reactant can be effectively used.

The temperature of the IC reaction part is preferably normal temperature (room temperature), but may be heated to a temperature up to about 200 ° C.

The TC combustion section and the IC reaction section may be provided in series or in parallel. This is because the effect that can be regenerated by the inorganic acid is the same.

Next, any known method may be used for the dehumidifying section. For example, as the dehumidifying section, a method of cooling to a constant temperature is preferable. Particularly preferably, using an electronic cooler, 10
It is to keep at a constant temperature of ℃ or less, for example, about 1 ℃. In this way, the dew point of water becomes constant and the quantitative measurement of carbon dioxide (CO ₂ ) by the non-dispersive infrared analyzer is stabilized.

Next, the carbon dioxide gas detection unit uses a non-dispersive infrared analyzer as an example. This is because the quantitative measurement of carbon dioxide can be performed most accurately.

In the present invention, as a preferable constitution, an oxidation catalyst or IC
When the deterioration of the reactant occurs and the regeneration treatment is required, the regeneration treatment program is operated to automatically inject the inorganic acid.

In the present invention, there may be provided means for integrating the sample injected into the TC combustion section and the number of injections to obtain the total injection amount, and providing an indicator for displaying the total injection amount.

Alternatively, the total injection amount that requires the activation process of the TC oxidation catalyst may be set in advance, and the activation process of the catalyst may be automatically performed when the integrated value reaches the set value. Further, a means for injecting a volatile inorganic acid into the TC oxidation catalyst heated to 300 ° C. or higher may be provided as the activation treatment of the TC oxidation catalyst.

Further, the inorganic carbon concentration in the sample, the injection amount, and the inorganic carbon amount integrated from the injection number may be always displayed. In this case, when the integrated amount of inorganic carbon exceeds a preset value, the IC reactant may be automatically replenished or regenerated. Further, in this case, the IC reactant is a solid acid, which is dispersed or arranged in a water column, and a degassed gas containing no CO ₂ is aerated, and the CO generated from the IC reactor is aerated.
_It is an inorganic carbon measuring circuit of a type in which ₂ is extracted and transferred to the detection unit, and means for injecting an acid may be provided to regenerate this solid acid.

As yet another aspect of the present invention, the TC combustion tube and the IC reactor are connected in series on the carrier gas flow path, and the carrier gas and drain (condensed water from the sample) discharged from the TC combustion tube are In the TOC meter flowing into the IC reactor, the inorganic carbon integrated amount (inorganic carbon concentration × injection amount × injection number) is calculated and stored from the measured inorganic carbon value of the sample,
If the value exceeds the preset value, the volatile inorganic acid is injected into the TC combustion tube (on the catalyst) to activate the catalyst and at the same time.
The IC reactant may be regenerated at the same time by the acidic product generated from the TC combustion tube.

[Operation] Since the regeneration process is automatically performed before the TOC measurement value becomes bad, the following operations are available.

No need for re-measurement and always reliable measurement value.

The maintenance work of the operator is reduced. Further, it has the following effects.

The TC oxidation catalyst has a reduced oxidizing ability due to the accumulation and contact of the catalyst poison component contained in the sample. In addition, IC components such as carbonates and hydrogen carbonates in the sample are thermally decomposed into oxides and accumulated on the catalyst. These oxides of alkali and alkaline earth absorb or release CO ₂ depending on the temperature, which causes so-called respiration action and causes the stability of measured values to be lowered.

Also, these alkaline substances strongly corrode the catalyst and the TC combustion tube.

When a catalyst in such a state is treated with an inorganic acid (hydrochloric acid is particularly preferable), the noble metal-based catalyst activates the catalyst and neutralizes the oxidative substances that accumulate harmful effects on the catalyst. Fixed in chloride. Chloride (eg NaC
l) does not react with CO ₂ and has a weak effect on the catalyst and combustion tube.

In the past, when the catalyst deteriorated, it was replaced with a new one, or with a precious metal catalyst such as platinum, the catalyst was taken out and washed by heating in an acid solution.

When using a strongly acidic ion exchange resin as the IC reactant,
When measuring the sample containing the IC reactant components from the reaction of _{R-SO 3 H + NaHCO 3} → R-SO 3 Na + H 2 CO 3, the ion-exchange group of the ion-exchange resin (-H ⁺⁾
Will eventually decrease and will eventually not react with the IC component. In this case, for example, if it is reacted with hydrochloric acid, it can be regenerated by the following formula.

R—SO ₃ Na + HCl → R—SO ₃ H + Nacl [Examples] Examples of the present invention will be described below. The present invention can be applied in various ways without being limited to the following examples.

FIG. 1 shows an embodiment of the device of the present invention.

The carrier gas supplied from the carrier gas flow rate control unit 1 is the TC sample injection port 2, the TC oxidation catalyst 4 in the TC combustion pipe 5, the connection pipe 6, the IC reactor 8, the dehumidification unit 11, and the carbon dioxide gas detection unit 12. Will be washed out in that order. In the TC combustion section, a TC combustion tube 5 is arranged in a TC furnace 3, and a TC oxidation catalyst 4 is filled in the TC combustion tube 5. The IC reaction part is composed of an IC sample inlet 7, an IC reactor 8 and an IC drain valve 10.
IC reactant 9 is filled.

The measurement sample 19 includes a multi-port valve 17 (a 4-port valve is shown as an example) to a sample injector (syringe pump).
16 automatically injected, TC sample injection port 2, TC oxidation catalyst 4 in TC combustion tube 5, connection pipe 6, IC reactor 8, dehumidification section
After passing through 11 and the carbon dioxide detector 12, the total carbon amount (Ct) in the sample is quantitatively measured.

Separately, the measurement sample 19 is automatically injected from the multiport valve 17 by the sample injector (syringe pump) 16, and the IC sample injection port 7, the IC reactant 9 in the IC reactor 8, the dehumidifying section 11, and the carbon dioxide gas are injected. After passing through the detector 12, the amount of inorganic carbon (Ci) in the sample is quantitatively measured.

Then, in the data processing unit 13, based on the above formula [I], TO
C is calculated and displayed on the display unit 14.

The operation control unit 15 reads the data of the data processing unit 13, and then the sample injector (syringe pump) from the multiport valve 17 is read.
Automatically injecting sample by 16 and TC sample inlet 2
Or switching the sample injection to the IC sample injection port 7, IC
Open the drain valve 10 and overflow IC
Control is performed to drain excess liquid as a drain.

In the above device, the inorganic acid aqueous solution 18 is arranged, the operation control unit 15 reads the data of the data processing unit 13, and the integrated value of the sample injection amount injected from the TC sample injection port 2 and / or the IC sample injection port 7 When the integrated value exceeds a certain value, manually or automatically by an instruction from the operation control unit 15,
A sample injector (syringe pump) 16 is used to inject an inorganic acid aqueous solution into the TC sample inlet and / or the IC sample inlet 7 from the multiport valve 17 to regenerate the TC oxidation catalyst 4 and / or the IC reactant 9. To do. When a precious metal such as platinum is used as the TC oxidation catalyst, activation of the catalytic ability can be maintained.

In the present invention, when hydrochloric acid is used as the inorganic acid, a preferable example of a single injection amount is, for the TC oxidation catalyst, for example, when 2N hydrochloric acid is used, injection of about 200 μ × 3 times is sufficient, When using 2N hydrochloric acid for the IC reactant
5 ml x 1 injection is enough.

The present invention has the injection mechanism for injecting hydrochloric acid and the same into the TC combustion tube and the IC reactor in the TOC meter, and if the operator specifies the execution of the regeneration process, only the TC catalyst or only the IC reactant or It is also possible to execute a program for continuously regenerating the TC catalyst and the IC reactant.

Next, another embodiment will be described.

Degradation of TC catalysts (precious metal-based catalysts such as platinum, copper oxide, cobalt oxide, etc.) depends on the amount of inorganic components contained in the sample accumulated on the catalyst or the total contact time if it is volatile. . Therefore, in general, when measuring a sample of almost the same quality (for example, in river water or seawater), it depends on the total injection amount (injection amount x number of times) injected on the catalyst, and this is always accumulated and stored. However, if the injection amount that is considered to affect the measured value is set in advance and the regeneration treatment (activation treatment) is always performed before that, the measurement can always be performed under good catalyst conditions.

Furthermore, river water, lake water, and tap water contain inorganic compounds in the form of carbonates (or bicarbonates) such as calcium carbonate and magnesium carbonate, which are thermally decomposed on the TC catalyst. Accumulates in the form of oxides.

This oxide absorbs CO ₂ with the TC furnace temperature lowered,
Raising the furnace temperature also causes a breathing action such as releasing CO ₂ to delay the stabilization of the TOC meter, or it is an alkaline substance, which has strong reactivity and is a major cause of catalyst deterioration.

On the other hand, carbonate (or hydrogencarbonate) in the sample is exactly the IC component and is measured as IC in the IC reaction part,
Accurate calculation can be performed by calculating and storing the IC integrated amount (IC concentration x injection amount x number of times) and comparing it with a preset value to determine the timing of the TC catalyst regeneration process. become.

As a regeneration treatment (activation treatment), a volatile inorganic acid (desirably an inert gas containing oxygen (preferably only inert gas or pure oxygen)) can be used under the condition that the temperature is raised to 300 ° C or higher (desirably 600 ° C) or higher and an inert gas containing oxygen flows. HCl) has the following effects.

Since an alkaline substance such as CaO becomes a neutral salt such as chloride, it does not react with CO ₂ and does not deteriorate the catalyst.

Hydrochloric acid has a function of activating a precious metal catalyst such as platinum.

On the other hand, phosphoric acid or the like is usually used as the IC reactive agent,
This reacts with the carbonate in the sample to generate CO ₂ .

Na ₂ CO ₃ + H ₃ PO ₄ → Na ₂ HPO ₄ + CO ₂ + H ₂ O Therefore, phosphoric acid is gradually neutralized and its reaction power decreases. This is the total amount of IC in the injected sample (IC concentration × injection amount ×
Since it largely depends on the number of times), this value may be stored and the timing of the phosphoric acid replenishment timing may be determined.

Furthermore, in the method of reacting the IC reaction with the sample by dispersing or immersing a solid acid such as a strongly acidic ion exchange resin in water, the exchange group (H ⁺ ) of the ion exchange resin is ion-exchanged with the carbonate in the sample. Injected because the reaction gradually decreases
The timing of reproduction processing can be determined from the total amount of ICs.

The regeneration process is performed, for example, by injecting hydrochloric acid into the IC reactor.

Also, when the TC combustion tube and IC reactor are connected in series (series), when the TC catalyst regeneration time is judged from the integrated amount of IC and hydrochloric acid is injected onto the catalyst, the TC catalyst regeneration is performed at the same time.
When the drain from the TC combustion tube (strongly acidic drain containing a large amount of hydrochloric acid) uses an inorganic acid as the IC reactor agent, the acid is replenished and a strongly acidic ion exchange resin is used. Has the effect of performing the reproduction.

EFFECTS OF THE INVENTION The present invention is provided with a means for injecting an inorganic acid and a means for integrating the sample injection amount into the TC combustion section and / or the IC reaction section, so that the integrated value of the sample injection quantity is a constant value. When it exceeds the limit, it is possible to provide a TOC meter that is injected with an inorganic acid and can perform the regeneration process or the activation process of the TC oxidation catalyst or IC reactant manually or automatically if the operator specifies. did it.

Furthermore, the cumulative injection amount is calculated from the sample injection amount and the number of times, and based on this, the timing of the regeneration process is predicted in advance,
It was possible to provide a TOC meter capable of automatically performing a regeneration treatment or an activation treatment of an IC reactive agent.

Further, since the regeneration processing program can be executed while the TC oxidation catalyst and the IC reactant are set in the TOC meter, the maintenance man-hour of the operator can be significantly reduced. .

Further, since the timing of regeneration of the TC oxidation catalyst or the IC reactant is judged from the integrated sample injection amount or integrated IC amount, it has become possible to prevent problems in the measured value of the sample (such as deterioration in sensitivity and reproducibility).

[Brief description of drawings]

 FIG. 1 shows an embodiment of the device of the present invention. 1: Carrier gas flow controller 2: TC sample inlet, 3: TC furnace 4: TC oxidation catalyst, 5: TC combustion tube 7: IC sample inlet, 8: IC reactor 9: IC reactant, 10: Drain Valve 11: Dehumidifier, 12: Carbon dioxide detector 13: Data processor, 14: Display 15: Operation controller, 16: Sample injector 17: Multiport valve, 18: Inorganic acid

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Hiroaki Matsuhisa, 1st Nishinokyo Kuwabara-cho, Nakagyo-ku, Kyoto, Kyoto Prefecture Inside the Sanjo Factory, Sanjo Factory (72) Hideyuki Miki 1st Nishinokyo-Kuwabara-cho, Nakagyo-ku, Kyoto, Kyoto Prefecture Shimadzu Sanjo Factory (56) Reference JP-A-52-48392 (JP, A)

Claims (1)

[Claims] 1. A total organic carbon meter comprising at least a carrier gas supply section, a total carbon combustion section using an oxidation catalyst, an inorganic carbon reaction section using an inorganic carbon reactant, a dehumidification section, and a carbon dioxide gas detection section. A means for obtaining an integrated amount of inorganic carbon from the concentration of inorganic carbon detected by the carbon dioxide detection part; and a means for injecting an inorganic acid into the all-carbon combustion part when the integrated amount of the inorganic carbon exceeds a certain value. And a total organic carbon meter, wherein the total carbon combustion section and the inorganic carbon reaction section are connected in series.