JPH076970B2 - Total Organic Carbon Meter with Reagent Regeneration Means - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial application] The present invention relates to a regeneration treatment of a reactant in an inorganic carbon reaction part of an all-organic carbon meter.

[Prior Art] A total organic carbon meter is mainly used for measuring total organic carbon in water (Total organic carbon).
c 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 been used as an essential measuring means for water quality control of water and sewage, groundwater, rivers, etc. in recent years. It is a very important measuring means for water quality control such as electronic and precision industries. For these industrial applications, T on the order of ppb (ppb is 1/1000 of ppm)
OC water quality management is required.

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 gas 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 a cation 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 IC reactive agent deteriorates, so that the operator manually operates the IC reactive agent replacement and regeneration processing each time. There was an inconvenience that it had to be done in. That is, it has been necessary to disassemble the IC reaction part, replace the catalyst and the reactant inside, and reassemble it. Especially when the IC reactive agent deteriorates suddenly,
Difficult to repair.

The present invention, in order to solve the problems of the prior art described above, focusing on the fact that the peak shape generated by the detection of CO ₂ generated from inorganic carbon changes due to the deterioration of the IC reactant, the peak of the precursor of the deterioration is determined. Based on the shape, when the peak width exceeds a specific value, by injecting an inorganic acid into the IC reaction part, the IC reactant can be regenerated manually or automatically if the operator specifies. Provide a TOC meter that can.

[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 sample measurement in an all-organic carbon meter including at least a carrier gas supply section, a TC combustion section using an oxidation catalyst, an IC reaction section using an IC reactant, a dehumidification section, and a carbon dioxide detection section. When the peak width of the peak generated by the above is 1.5 times or more of the preset normal peak width, a means for regenerating the IC reactant by adding an inorganic acid to the IC reaction part is provided. Is a total organic carbon meter having a means for regenerating a reactant.

A characteristic of the present invention is that the TOC meter is provided with a means for injecting an inorganic acid for regenerating or activating the IC reactant, and the peak width generated by the sample measurement is a preset normal peak. When the width exceeds 1.5 times, the IC
There is a means to regenerate the IC reactant by adding an inorganic acid to the reaction part. This can be done automatically or manually
The IC reactant can be regenerated or activated. If it can be automatically performed, the regeneration process can be automatically performed without stopping the supply of the carrier gas, so that the regeneration process can be performed quickly and accurately without interrupting the measurement.

Although the peak width are expressed in time W ₁ until the rising and the peak to the end of the peak width (FIG. 5), the half width W ₂ of the peak (5
It can also be represented by a diagram).

In the present invention, the inorganic acid injected into the IC reaction part is hydrochloric acid,
Any inorganic acid such as phosphoric acid, nitric acid or sulfuric acid may be used, but hydrochloric acid is preferable from the viewpoint of easy handling. 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 capable of converting inorganic carbon into carbon dioxide and regenerating 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 configuration, when the IC reactive agent is deteriorated and a regeneration process is required, the regeneration process program is operated to automatically inject the inorganic acid.

[Operation] In the present invention, the deterioration determination and the regeneration process of the IC reactive agent are performed in advance from the information on the peak shape of the TOC data.

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 reactant component.
In this case, for example, if it is reacted with hydrochloric acid, it can be regenerated by the following formula.

As _{R-SO 3 Na + HCl →} R-SO 3 H + NaCl The IC reactant, when an inorganic acid such as phosphoric acid or hydrochloric acid in aqueous solution, the concentration of acid is diluted with the measurement of the sample, become specific peak width At this time, by injecting an inorganic acid, the acid concentration becomes constant, and accurate measurement can be performed.

[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 gas detection unit 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 part 11, and the carbon 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.

FIG. 2 shows a main part centering on the IC reaction part 8 of FIG.

In the above apparatus, the TOC measurement chart appears as shown in FIGS. 4 and 5. Here, in the steady state, the result is as shown in FIG. 4, but when the measurement is continued, the peak height becomes gradually lower and the peak width becomes wider as shown in FIG. Therefore, when the above-mentioned peak width becomes 1.5 times or more of the normal time, manually from the inorganic acid aqueous solution 18 or automatically by the instruction of the operation control unit 15, from the multiport valve 17 to the sample injector (syringe pump) 16 An inorganic acid aqueous solution is injected into the IC sample injection port 7 to regenerate the IC reactant 9.

When hydrochloric acid is used as the inorganic acid in the present invention, a preferable example of a single injection amount is, for example, for an IC reactant.
When using 2N hydrochloric acid, it is sufficient to inject about 5 ml × 1 time.

The present invention has an injection mechanism for injecting hydrochloric acid and this into the IC reactor in the TOC meter, and if the operator specifies the execution of the regeneration process, only the IC reaction is completed or the TC catalyst and the IC reactant are continued. It is also possible to execute a program for reproduction processing.

Next, another embodiment will be described. A detailed description of the preferred IC reaction section is given below.

Strongly acidic ion exchange resin (H
Type) (for example, "Amberlite IR-120B" (registered trademark of Rohm and Haas Company, USA), manufactured by Organo Corporation) is contained and dispersed in water.

If it leaves accommodating a strongly acidic ion exchange resin, which cation ion exchange, such as bicarbonate in the sample and (e.g. _{R-SO 3 H + NaHCO 3} → R-SO 3 Na + H 2 CO 3), generated at this time By bubbling the product, carbonic acid, with a carrier gas, it is easily converted to carbon dioxide (H ₂ CO
_{3 → H 2 0 + CO 2} ).

In this case, even if the reduced exchange capacity of a strongly acidic ion-exchange resin by the ion exchange reaction, easily reproduced by an inorganic acid infusion (e.g. _{R-SO 3 Na + HCl →} R-SO 3 H + NaCl)
Therefore, this ion exchange resin can be repeatedly used. By accommodating the strongly acidic ion exchange resin in the IC reactor 8 in this way, the operation becomes simpler.
As long as the solid acid does not interfere with the above reaction, an external one can be appropriately used because it is a strongly acidic ion exchange resin.

[Application example] A granular strongly acidic ion exchange resin (H type) is put into water in an IC reactor, and a carrier gas is bubbled from under the IC reactor to disperse and float the ion exchange resin. When injected, IC component (carbon ion, hydrogen carbonate ion)
Is the following equation, to liberate CO ₂ reaches to the CO ₂ detector together with the carrier gas, issues a signal peak shape.

R-SO ₃ H + NaHCO ₃ → R-SO ₃ Na + H ₂ CO ₃ H ₂ CO ₃ → H ₂ O + CO ₂ This peak shape is the performance of the ion exchange resin used, IC
The structure of the reactor varies depending on the efficiency of gas-liquid contact of the carrier gas, but these become fixed under the specified conditions.

This peak shape changes as the exchange capacity of the ion exchange resin decreases.

For example, the relationship between the peak width and the peak area is obtained as shown in FIG. In FIG. 3, the IC concentration in the sample is calculated from the peak area, but the peak area can be measured up to the timing of the IC calculation amount Q ₂ , but the time when the regeneration process is required is near. On the other hand, the peak width tends to increase for a while. For example, if you pay attention to the timing when the peak width is reduced to 1.5 times or more of that at the start (when using a new ion exchange resin or after regeneration treatment), this timing (Q Up to ₁ ), measurement is sufficient, but it is time to regenerate.

For example, find the peak width at normal time at the start,
After that, the ratio of [current peak width / normal peak width] is always checked, and if this value reaches a certain value (ratio at the timing of Q ₁ ), reproduction processing is performed.

Therefore, by grasping this timing, it is possible to display the necessity of performing the regeneration process and further perform the regeneration process by injection of hydrochloric acid.

In the present invention, the deterioration of the TC oxidation catalyst or IC reactant is judged from the repeatability (standard deviation: SD, or coefficient of variation: CV) when the sample or standard solution is repeatedly measured, and the regeneration program is automatically executed. It is also possible to let.

[Advantageous Effects of the Invention] In order to solve the above-mentioned problems of the prior art, the present invention focuses on the fact that the peak shape generated by the detection of CO ₂ generated from inorganic carbon changes due to the deterioration of the IC reactant, Judgment of the precursor is based on the peak shape, and when a specific heat width is reached, inorganic acid is injected into the IC reaction section to regenerate the IC reaction agent manually or automatically when the operator specifies. It was possible to provide a TOC meter that can do this. Also, since the regeneration processing program can be executed while the IC reactive agent is set in the TOC meter, the remarkable effect that the maintenance man-hours of the operator can be greatly reduced can be exhibited.

[Brief description of drawings]

FIG. 1 shows an embodiment of the device of the present invention. FIG. 2 shows an essential part of the present invention. FIG. 3 shows an application example of the present invention. 4 and 5 are measurement charts of the present invention. 1: Carrier gas flow controller 2: TC sample injection port, 3: TC furnace 4: TC oxidation catalyst, 5: TC combustion tube 7: IC sample injection port, 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

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 regenerating the inorganic carbon reactive agent by adding an inorganic acid to the inorganic carbon reaction part when the width of the peak generated by the sample measurement is 1.5 times or more the width of the peak under normal conditions A total organic carbon meter having a means for regenerating a reactant characterized by: