JPH0331760A - Total organic carbon meter - Google Patents

Abstract

PURPOSE:To decrease the man-hours for maintenance by operator by providing a device for injecting an inorg. acid to a total carbon combustion section and/or inorg. carbon reaction section and regenerating a total carbon oxidation catalyst and inorg. carbon reacting agent. CONSTITUTION:A measuring sample 19 is automatically injected from a multiport valve 17 to a sample injecting device 16 and is passed through a TC sample injection port 2, the TC oxidation catalyst 4 in a TC combustion pipe 5, a connecting piping 6, an IC reactor 8, a dehumidifying section 11, and a carbon dioxide detecting section 12, by which the total carbon content Ct in the sample is quantitatively measured. Separately, the sample 19 is automatically injected from the multiport valve 17 by the sample injecting device 16 and is passed through an IC sample injection port 7, an IC reacting agent 9 in the IC reactor 8, etc., by which the inorg. carbon content Ci in the sample is quantitatively measured. The total org. carbon TOC is measured in a data processing section 13 and is displayed 14. An aq. soln. 18 of the inorg. acid is disposed in this case and the aq. soln. of the inorg. acid is injected to a total carbon combustion sample injection port 2 and/or inorg. carbon IC sample injection port 7 manually or automatically by the instruction of an operation control section 15 to regenerate the TC oxidation catalyst 4 and the IC reacting agent 9.

Description

Detailed Description of the Invention [Field of Industrial Application] The present invention relates to a regeneration treatment or activation treatment of an oxidation catalyst in a total carbon combustion section and/or a reactant in an inorganic carbon reaction section of a total organic carbon meter. .

[Prior art] Total organic carbon meters mainly measure total organic carbon (To(alo)) in water.
The constant (Ct) of rganic carbon, hereinafter referred to as TOC (1), is determined, and the inorganic carbon concentration (Ci) in the sample is determined separately in the inorganic carbon reaction section. Quantitative measurement is performed using an external analyzer, and the quantitative value of TOC is determined using the following formula.

TOC=Ct-Ci ......Formula [
I] TOC has traditionally been used as an indispensable measurement method for water quality control in water supply, sewage, groundwater, rivers, etc., but in recent years it has also been used in electronic and other applications such as ultrapure water for cleaning semiconductors and IC chips.
It has become an extremely important measurement method for water quality control in precision industries and other industries. For these industrial purposes, ppb (ppb is 1 ppm)
/1000) water quality control is required.

By the way, a TOC meter consists of a carrier gas supply section, a total carbon combustion section (TC combustion section), an inorganic carbon reaction section (IC reaction section),
It is composed of at least a dehumidifying section and a carbon dioxide gas detecting section. Platinum, cobalt oxide, palladium, chromate, etc. are used as oxidation catalysts in the TC combustion section, and I
A reactant such as an inorganic acid or a cation exchange resin is used in the C reaction part.

[Problems to be Solved by the Invention] However, in conventional TOC meters, the TC oxidation catalyst or 16 reactant deteriorates after being used for a certain period of time. There was an inconvenience that the replacement and regeneration process had to be performed manually. That is, T
It was necessary to disassemble the C combustion section and IC reaction section, replace the internal catalyst and reactant, and reassemble them, which was a cumbersome task.

In order to solve the problems of the prior art described above, the present invention
By providing a means for injecting inorganic acid into the combustion section and/or IC reaction section, regeneration or activation of the TC oxidation catalyst and IC reactant can be performed manually or automatically if specified by the operator. To provide a TOC meter that can perform accurate measurements.

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

That is, the present invention provides a total organic carbon meter comprising at least a carrier gas supply section, a TC combustion section using an oxidation catalyst, an IC reaction section using an inorganic carbon reactant, a dehumidification section, and a carbon dioxide detection section. TC combustion section, and/
Alternatively, the total organic carbon meter is characterized in that a means for injecting an inorganic acid for regenerating the TC oxidation catalyst and/or the 10 reactants into the IC reaction section is provided.

The characteristic feature of the present invention is that the TC oxidation catalyst and/or
Alternatively, the TOC meter is provided with a means for injecting an inorganic acid for regenerating or activating the IC reactant. Thereby, the TC oxidation catalyst and/or the IC reactant can be regenerated or activated automatically or manually. If this can be done automatically, the regeneration process can be performed automatically without stopping the supply of carrier gas, so the regeneration process can be performed quickly and accurately without the possibility of the baseline going out of order.

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, or sulfuric acid, but is preferred from the viewpoint of ease of handling. is hydrochloric acid.

It is preferable to use the inorganic acid as an aqueous solution in order to protect the measurement system. When preparing an aqueous solution, the dilution ratio can be set arbitrarily. The means for injecting the inorganic acid preferably consists of 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 preferably comprises, for example, a pressure reducing valve, a pressure gauge, a flow controller, a flow meter. This is to quantitatively feed pure gas into the measurement system. High purity air or the like can be used as the carrier gas.

Next, precious metals such as platinum are added to the TC combustion section as an oxidation catalyst.
Cobalt oxide, palladium, chromate, etc. can be used. When precious metal catalysts such as platinum are used, in addition to regeneration treatment by injecting inorganic acids,
It is convenient because it allows catalytic ability activation treatment. The temperature of the TC combustion section is preferably about 400°C to 950°C.

Next, as the IC reaction section, any reaction device can be used as long as it is capable of converting inorganic carbon (carbonate carbon) into carbon dioxide and can be regenerated with an inorganic acid. As the reactant used in such an IC reaction part, for example, an inorganic acid such as hydrochloric acid, phosphoric acid, nitric acid, or sulfuric acid may be used as an aqueous solution, or a recyclable solid acid or a strongly acidic ion exchange resin may be used. It may also be a reactant such as. Preferred IC reactants include:
A strongly acidic ion exchange resin is dispersed in an aqueous solution and bubbled with gas. This is because a so-called fluidized bed reaction can be performed and the active surface of the reactant can be effectively utilized.

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

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

Next, regarding the dehumidifying section, any known system may be used. For example, it is preferable that the dehumidifying section be of a cooling type to a constant temperature. Particularly preferably, using an electronic cooler, 1
The temperature is maintained at a constant temperature of 0° C. or lower, for example, about 1° C. In this way, the dew point of moisture becomes constant, and quantitative measurement of carbon dioxide (CO2) by a non-dispersive infrared analyzer becomes stable.

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

In the present invention, preferred configurations include an oxidation catalyst and an I
When deterioration of the C reactant occurs and regeneration treatment is necessary, a regeneration treatment program is run to automatically inject the inorganic acid.

[Function] The TC oxidation catalyst has a reduced oxidation ability due to accumulation or contact with catalyst poison components contained in the sample.

Furthermore, IC components such as carbonates and hydrogen carbonates in the sample are thermally decomposed into oxides, which accumulate on the catalyst. These alkali and alkaline earth oxides change depending on the temperature.
It absorbs and releases O2, a so-called breathing effect, which causes a decrease in the stability of measured values. The reaction is shown below.

Pyrolysis CaCo3 CaO+CO2 Room temperature Also, these alkaline substances strongly corrode the catalyst and TC combustion tube.

When a catalyst in such a state is treated with an inorganic acid (especially preferably hydrochloric acid), the catalyst is activated in the case of noble metal catalysts, and the oxidizing substances that have accumulated on the catalyst and cause harmful effects are neutralized. is fixed in chloride. Chloride (e.g. Na
C1) does not react with CO2 and has a weak effect on the catalyst and combustion pipe.

Conventionally, when a catalyst deteriorates, it is replaced with a new one, or in the case of a noble metal catalyst such as platinum, the catalyst is taken out and heated and washed in an acid solution.

When a strongly acidic ion exchange resin is used as an IC reactant, when a sample containing an IC component is measured, R-3Q3H+Na
By the reaction of HCQ3→R-8Q3Na+H2CO+,
The ion exchange group (-H+) of the ion exchange resin decreases and eventually stops reacting with the IC component. In this case, for example, by reacting with hydrochloric acid, it can be regenerated according to the following formula.

R-5CbNa+ HCl→R-8CbH+ Na
c1 [Example] The present invention will be described in detail below. Note that the present invention is not limited to the following examples and can be applied in various ways.

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

The carrier gas supplied from the carrier gas flow rate control section 1 is supplied to the TC sample injection port 2, the TC oxidation catalyst 4 in the TC combustion tube 5, the connecting pipe 6, the IC reactor 8, the dehumidification section 11, and the carbon dioxide detection section 12. are carried out in this order. The TC combustion part is T
A TC combustion tube 5 is disposed within the CCa, and a TC oxidation catalyst 4 is filled in the TC combustion tube 5. The IC reaction section is
Sample injection lower, IC reactor 8, IC drain valve 10
An IC reactor 8 is filled with an IC reactant 9.

A measurement sample 19 is automatically injected by a sample injector (syringe pump) 16 from a multiport valve 17 (a 4 multiport valve is shown as an example), and is injected into the TC sample inlet 2 and the TC oxidizer in the TC combustion tube 5. Catalyst 4, connection piping 6,
The sample passes through the IC reactor 8, the dehumidifying section 11, and the carbon dioxide gas detecting section 12, and the total carbon content (Ct) in the sample is quantitatively measured.

Separately, the measurement sample 19 is automatically injected from the multi-port valve 17 by the sample injector (syringe pump) 16, and the IC reactant 9 in the IC sample injection lower, the IC reactor 8,
The sample passes through the dehumidifying section 11 and the carbon dioxide gas detecting section 12, and the amount of inorganic carbon (C1) in the sample is quantitatively measured.

Then, the data processing unit 13 calculates the TOC based on the above-mentioned formula [1F, and displays it on the display unit 14.

The operation control unit 15 reads the data from the data processing unit 13 and automatically injects the sample from the multi-port valve 17 with the sample injector (syringe pump) 16 to the TC sample injection port 2 or the IC sample injection lower. Controls include switching sample injection, opening the IC drain valve 10, and draining excess IC liquid that overflows.

In the above apparatus, the inorganic acid aqueous solution 18 is placed, and the sample injector (syringe pump) 1
6, the inorganic acid aqueous solution is injected into the TC sample injection "-" 2 and 1/or the IC sample injection lower, and the TC oxidation catalyst 4 is injected.
and/or regenerating the IC reactant 9. When a noble metal such as platinum is used as a 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 the amount of injection is -1 - minutes for a TC oxidation catalyst, for example, when 2N hydrochloric acid is used, about 2001111 x 3 injections is required. and for the IC reactant, 2N
When using 5ml of hydrochloric acid, one injection of 5ml is sufficient.

The present invention combines the acid in the TOC meter needle and the TC combustion tube and N
It has an injection mechanism that injects into the C reactor, and when the operator specifies execution of regeneration processing, it executes a program to regenerate only the TC catalyst, only the IC reactant, or the TC catalyst and the IC reactant in succession. You can also do that.

Next, other embodiments will be explained. A detailed explanation of the preferred IC reaction section is given in Section F. In the 3rC reaction section, a strongly acidic ion exchange resin (n-type) (for example, L Amberlite R-120BJ (Rohm & Co., Ltd., USA) is used as the solid acid.・Haas Co., Ltd. (registered trademark), Organo Co., Ltd.) is contained and dispersed in water.

If a strongly acidic ion exchange resin is stored, it will exchange ions (e.g., R-50311+ Na1ICO3 → R-803Na+) with strong ions such as hydrogen carbonate in the sample.
l12CO3) L,,, the product produced at this time, i.e. carbonic acid, is converted into carbon dioxide (ti2CO3=
i1201CO2).

In this case, even if the equipment has a low exchange capacity for the strongly acidic ion exchange resin due to the ion exchange reaction, the inorganic acid that is injected can easily re-grow it (for example, RSO3Na+ItCl-11-
3O311+NaC1) 1': Can this ion exchange resin be used repeatedly? By accommodating the strongly acidic ion exchange resin in the IC reactor 8 in this way, the operation becomes even simpler. Note that solid acids other than strongly acidic ion exchange resins can be used as appropriate as long as they do not inhibit the above reaction. Furthermore, even if an inorganic acid such as hydrochloric acid, phosphoric acid, nitric acid, or sulfuric acid is present in an aqueous solution as a reactant in the IC reaction part, the concentration of the acid can always be kept constant by injecting the inorganic acid of the present invention. and reactivity can be kept constant.

[Application example] In the present invention, the deterioration of the TC oxidation catalyst or IC reactant is judged from the degree of repetition (standard deviation: SD or coefficient of variation: CV) when a sample or standard solution is repeatedly measured 7, and the deterioration of the IC reactant is determined automatically. It is also possible to run the playback program automatically.

[Effects of the Invention] The present invention provides a means for injecting inorganic acid into the TC combustion section and/or the IC reaction section, so that the TC oxidation catalyst and I
Regeneration treatment of C reactant 1. Alternatively, a TOC revision could be provided in which the activation process could be performed manually or automatically if specified by the operator. Also, T.C.
The regeneration treatment program is executed while the oxidation catalyst and rC reactant remain inside the TOC meter needle (1,!), which is a remarkable feature that greatly reduces the amount of maintenance required by the operator. We were able to demonstrate a significant effect.

[Brief explanation of drawings]

FIG. 1 shows one embodiment of the device according to the invention.7.1:
To carry′-Gas flow control section

Claims (1)

[Claims] (1) Carrier gas supply section, all-carbon combustion section using an oxidation catalyst, inorganic carbon reaction section using an inorganic carbon reactant,
In a total organic carbon meter comprising at least a dehumidification section and a carbon dioxide detection section, a component for regenerating an oxidation catalyst and/or an inorganic carbon reactant is supplied to the total carbon combustion section and/or the inorganic carbon reaction section. A total organic carbon meter characterized by having a means for injecting inorganic acid.