JPH06102270A - Quantity of carbon measuring equipment - Google Patents

Abstract

PURPOSE:To measure the quantity of organic carbon in a sample liquid accurately by eliminating the influence of variation of elements (e.g. organic carbon contained in reaction liquid) other than organic and inorganic carbons in the sample liquid. CONSTITUTION:A sample liquid is measured through first and second measuring systems 100, 101. In the first system 100, inorganic carbon is removed and carbon dioxide is produced from organic carbon and then the concentration of carbon dioxide is measured. In the second system 101, carbon is removed entirely and then the concentration of carbon dioxide is measured similarly to the first system 100. Measurements are fed to an operating means 53 where the measurement of the second system 101 is subtracted from the measurement of the first system 100. In this regard, the operating means 53 employs the measurement of first system 101 as a reference value for zero point adjustment thus dealing with the variation of elements other than organic and inorganic carbons in the sample liquid effectively.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a carbon content measuring device capable of measuring carbon content with high sensitivity and capable of accurately setting a zero point.

[0002]

2. Description of the Related Art Conventionally, as this type of carbon amount measuring device, the one disclosed in Japanese Patent Laid-Open No. 4-52555 is known. This carbon content measuring device is a reaction solution supply means for adding a reaction solution such as an acidic solution and an oxidizing agent to a sample solution, and an inert gas is fed into the sample solution to which the reaction solution has been supplied to stir the sample solution. A deaerator for expelling the contained inorganic carbon to the outside together with an inert gas, and a sample solution from which the reaction solution has been added and the inorganic carbon has been removed are heated to remove the inorganic carbon from the organic carbon contained in the sample solution. A reactor for producing carbon dioxide, an extractor for extracting the carbon dioxide produced in the reactor, and a measuring means for measuring the amount of carbon dioxide extracted by the extractor (for example,
Infrared spectrophotometer, gas chromatograph, etc.), wherein the deaerator contains a reaction liquid for measuring organic carbon (sulfuric acid, which is a strong acid, and sodium peroxodisulfate, which is an oxidizing agent). And a reaction solution for zero-point calibration (containing only strong acid such as sulfuric acid,
Second supply means for supplying (containing no oxidizer).

In the carbon content measuring apparatus constructed as described above, the reaction liquid for zero point calibration is supplied to the sample liquid from the second supply means, and the inorganic liquid is supplied by the reaction liquid for zero point calibration. The zero point of the measuring means is adjusted by the sample solution degassing only carbon, and after the zero point adjustment, the reaction solution for measuring organic carbon is supplied to the sample solution from the first supplying means to measure the organic carbon. After degassing the inorganic carbon with the reaction liquid for use, the carbon dioxide produced from the organic carbon is measured by the measuring means, and thereby the quantitative value of the organic carbon is calculated from the amount of the carbon dioxide.

[0004]

By the way, in the carbon content measuring apparatus configured as described above, how much organic carbon is contained in the sample solution is determined after the inorganic carbon in the sample solution is removed. , Carbon dioxide is generated from organic carbon, the amount of carbon dioxide is measured, and the detection value obtained at the time of the zero point adjustment is subtracted from the amount of carbon dioxide. Therefore, in the above carbon content measuring device,
During the measurement, for example, elements other than inorganic carbon and organic carbon in the sample solution (for example, the amount of the sample solution supplied, the amount of organic carbon contained in the reaction solution, and the degree of the influence of moisture interference on the above-mentioned measuring means). ) Fluctuates, even though the amount of organic carbon in the sample solution does not actually change,
There is a problem that the measured value by the measuring means changes, and as a result, the amount of organic carbon cannot be measured accurately.

The present invention has been made in view of the above circumstances, and is an element other than the inorganic carbon and the organic carbon in the sample solution (for example, the supply amount of the sample solution or the reaction solution). When the amount of organic carbon, the degree of moisture interference influence on the above-mentioned measuring means) changes, the influence of this change is eliminated,
Thus, it is an object of the present invention to provide a carbon amount measuring device capable of accurately measuring the amount of organic carbon contained in a sample liquid.

[0006]

In order to achieve the above object, the present invention has a first supply means for supplying an acidic solution and an oxidizing agent to a sample solution, and sends an inert gas to the sample solution, Inorganic carbon in the sample solution is removed by the acidic solution and the inert gas supplied by the first supply means, and then the sample solution is heated to organic carbon in the sample solution and the first supply. A first method for producing carbon dioxide from organic carbon in a sample liquid by reacting with an oxidizing agent supplied from the first means.
And a second supply means for supplying an acidic solution and an oxidizing agent to the same sample solution as the sample solution of the first system, and heating the sample solution to remove organic carbon in the sample solution. By reacting with the oxidizing agent supplied from the second supply means, carbon dioxide is generated from the organic carbon in the sample solution, and an inert gas is added to the sample solution containing inorganic carbon such as carbon dioxide. And a second system for removing inorganic carbon in the sample solution by the acidic solution and the inert gas supplied from the second supply means, and a second solution contained in the sample solution via the first system. The amount of organic carbon contained in the sample liquid of the first system by comparing the gas contained in the sample liquid that has passed through the second system with the organic carbon amount computing means. I am trying to do it.

[0007]

According to the present invention, in the first system, the inert gas is fed to the sample solution, and the acidic solution supplied by the first supply means and the inorganic substance in the sample solution are supplied by the inert gas. The carbon is removed, and then the sample solution is heated to react the organic carbon in the sample solution with the oxidizing agent supplied from the first supply means, so that the organic carbon in the sample solution is oxidized. Carbon is produced. In the second line,
The sample solution of the same system as the first system is heated, and the organic carbon in the sample solution reacts with the oxidant supplied from the second supply means, so that the organic carbon in the sample solution is oxidized. Carbon is further generated, and an inert gas is sent to the sample solution containing the inorganic carbon such as carbon dioxide, and the acidic solution and the inert gas supplied from the second supply means Inorganic carbon is removed. On the other hand, in the organic carbon amount calculating means, the gas contained in the sample liquid passing through the first system is compared with the gas contained in the sample liquid passing through the second system, thereby The amount of organic carbon contained in the sample liquid of the system 1 can be determined.

That is, in the carbon content measuring apparatus of the present invention, the second system, which is provided in parallel with the first system, can be used as a system for zero point adjustment. Elements other than airframe carbon and organic carbon (eg,
The amount of sample liquid supplied, the amount of organic carbon contained in the reaction liquid,
Even if the above-mentioned influence of moisture interference on the measuring means is varied to affect the first system, the second system is also affected accordingly. The organic carbon amount calculating means can offset these effects, and as a result, the organic carbon in the sample liquid can be accurately measured.

[0009]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment of the present invention will be described below with reference to FIG. First, the reference numeral 1 in this figure is a flow path through which a sample solution containing inorganic carbon and organic carbon is supplied, and the sample solution supplied through this flow path 1 is removed by a pump 2. It is designed to be sent to the airway 3. Further, a reaction liquid supply means 5 is provided in the flow path 4 located between the pump 2 and the deaerator 3, and the reaction liquid supply means 5 includes a storage container 6 in which the reaction liquid is stored, The flow path 7 connecting the storage container 6 and the flow path 4 and the reaction liquid in the storage container 6 are supplied to the flow path 4 through the flow path 7, whereby the reaction liquid is added to the sample solution in the flow path 4. And a pump 8 for adding. Also, this reaction liquid supply means 5
In addition, one system is further provided with a flow path 9 for supplying the reaction liquid in the storage container 6 and a pump 10.

The reaction solution stored in the storage container 6 is a strong acid solution such as sulfuric acid for expelling carbon dioxide which is an inorganic carbon contained in the sample solution and which is a weak acid.
It is composed of an oxidizing agent such as potassium peroxodisulfide for producing carbon dioxide which is an inorganic carbon from the organic carbon contained in the sample liquid. Also, the deaerator 3
Is a flow path 11 in which the sample solution to which the reaction solution has been added is stored, and an inert gas such as helium or nitrogen is sent to the lower part thereof.
And the inert gas supplied through the flow path 11 becomes a bubble inside the deaerator 3,
The mixed liquid of the sample liquid and the reaction liquid is stirred and mixed with each other, and carbon dioxide (inorganic carbon) in the sample liquid is degassed by the strong acid in the reaction liquid. In addition, what is provided in the middle of the flow path 11 is a flow rate control means 12 for adjusting the flow rate of the inert gas.

On the other hand, the outlet of the deaerator 3 is provided with a channel 13 for discharging the sample liquid after removing the inorganic carbon, and the end of this channel 13 is a pump 14 It is connected to the. Further, another flow passage 16 is connected to the middle of the flow passage 13 via a branch portion 15, and the end portion of the flow passage 16 is connected to a pump 17. The pump 14 and the pump 17 are driven by the same motor 18 in order to minimize the flow rate fluctuation, and the sample solution discharged by the pump 17 is supplied to the flow path 19. Has become. In this embodiment, the flow path is branched from the branch portion 15 to form two systems, and in the following description, the flow path on the pump 14 side is the first system 10.
It is expressed as 0, and the flow path on the pump 17 side is expressed as the second system 101.

First, the second system 101 located on the pump 17 side will be described. In the flow path 19 connected to the discharge side of the pump 17, the reactor 20 and the cooler 21 are arranged along the flowing direction of the sample solution. , A deaerator 22 is sequentially provided, and the passage 19 located between the cooler 21 and the deaerator 22 is connected to the passage 9 of the reaction liquid supply means 5 and the storage container 6 The reaction liquid is supplied into the sample liquid through the pump 10 and the channel 9. The pump 10 is controlled by a control unit (not shown) so as to discharge the same amount of the reaction liquid as the amount of the reaction liquid contained in the sample liquid flowing through the first system 100. The reactor 20 spirally winds the flow path 19 around the drum heater 20A to heat the sample solution in the flow path 19, and the reaction solution (oxidizing agent) is used in the reactor 20. Carbon dioxide is produced from the organic carbon by reacting it with the organic carbon in the sample liquid.

The cooler 21 is composed of a cooling pipe 23 formed in a spiral shape and an air cooling fan 24 for blowing air to the cooling pipe 23 to cool the cooling pipe 23.
Like the deaerator 3, the deaerator 22 stores the sample liquid,
Further, a flow path 25 for feeding an inert gas such as helium or nitrogen is connected to the lower part thereof, and the inert gas supplied through the flow path 25 becomes a bubble inside the deaerator 22. Then, the mixed liquid of the sample liquid and the reaction liquid is stirred and mixed with each other, and carbon dioxide (carbon dioxide generated from organic carbon) in the sample liquid is degassed by the strong acid in the reaction liquid. The one provided in the middle of the flow path 25 is a flow rate control means 2 for adjusting the flow rate of the inert gas.
It is 6.

At the outlet of the deaerator 22, there is provided a flow passage 27 for discharging the sample liquid after removing the carbon dioxide produced from the organic carbon, and the end portion of the flow passage 27. Is connected to the pump 28. On the other hand, the sample liquid discharged from the pump 14 of the first system 100 passes through the flow path 30 having the pipe length adjusting pipe 29 in the middle to the pump 31.
It is connected to the. The pipe length adjusting pipe 29 matches the volume of the first system 100 with the volume of the second system 101,
It is provided to make the measurement conditions of the first system 100 and the second system 101 the same. Further, in order to eliminate the difference between the flow rate of the sample liquid discharged by the pump 31 and the flow rate of the sample liquid discharged by the pump 28, the pump 31 and the pump 28 have the same motor 32.
The sample liquid discharged by the pump 31 is supplied to the flow path 33, and the sample liquid discharged by the pump 28 is supplied to the flow path 34. In addition, what is provided in the middle of the flow path 30 of the first system 100,
An overflow channel 35 for discharging the sample liquid overflowing from the channel 30 to the outside.

On the other hand, the flow path 33 of the first system 100 and the flow path 34 of the second system 101 both pass through the reactor 36. This reactor 36 has one drum heater 36A.
The flow path 33 and the flow path 34 are wound around the same with the same number of turns, and the sample solution in the flow paths 33 and 34 is heated at the wound position. Channel 33
Inside, the reaction liquid (oxidizing agent) is reacted with the organic carbon in the sample liquid to generate carbon dioxide from the organic carbon.

The flow path 33 of the first system 100 and the flow path 34 of the second system 101, which have passed through the reactor 36, reach the extractor 39 via fixed throttles 37 and 38, respectively. There is. The fixed throttles 37 and 38 correspond to the reactor 36.
The purpose of this is to increase the reaction pressure inside the reactor, and to prevent vaporization of the reaction liquid even if the temperature of the reactor 36 exceeds the boiling point of water. The extractor 39 is
Carbon dioxide and drain water (residuals) are provided for the sample liquids provided up and down and supplied through the flow paths 33 and 34, respectively.
Extraction towers 40 and 41 for gas-liquid separation into
0 and 41, and a cooling pipe 42 that cools the extraction towers 40 and 41.

Further, in the lower part of the extraction towers 40 and 41,
The flow path 3 has flow rate control means 43 and 44 for controlling the flow rate.
Flow paths 45 and 46 for feeding an inert gas such as helium and nitrogen for extracting carbon dioxide from the sample liquid supplied from 3, 34 are connected, and the extraction towers 40 and 41 are also connected.
Above the above, dehumidifiers 47 and 48 for drying the carbon dioxide and the inert gas separated in the extraction towers 40 and 41, and an infrared absorption meter 49 for measuring the concentration of carbon dioxide in the inert gas are provided. , 50, which are sequentially provided with a flow path 51,
52 are connected to each other. A measurement value indicating the concentration of carbon dioxide measured by the infrared absorption meter 49 of the first system 100 and a measurement value indicating the concentration of carbon dioxide measured by the infrared absorption meter 50 of the second system 101. The value and the value are supplied to the calculating means 53, and the calculating means 53
Then, the concentration of organic carbon in the sample solution is calculated by subtracting the measurement value of the infrared absorption meter 50 from the measurement value of the infrared absorption meter 49.

In FIG. 1, reference numerals 54 and 55 are flow paths for supplying and discharging cooling water to the cooling pipe 42 of the extractor 39. Also, the above-mentioned first
In the system 100 and the second system 101 of the pump 3
1. The structure downstream of the pump 28 is exactly the same.

Next, the operation of the carbon content measuring device configured as described above will be described. (1) Regarding the first system 100, after the reaction solution is added to the sample solution by the reaction solution supply means 5, the strong acid in the reaction solution causes no reaction in the sample solution, which is a weak acid, in the deaerator 3. Aircraft carbon is degassed. The sample liquid is heated in the reactor 36, and at this time, carbon dioxide is generated from the organic carbon in the sample liquid by the oxidizing agent in the reaction liquid. The carbon dioxide produced in the reactor 36 is extracted by the extractor 39.
After being extracted by, the concentration is measured by the infrared absorption meter 49.

(2) Regarding the second system 101, after the reaction solution is added to the sample solution by the reaction solution supply means 5, the sample solution which is a weak acid by the strong acid in the reaction solution in the deaerator 3 The inorganic carbon inside is degassed. The sample liquid is heated in the reactor 20, and at this time, carbon dioxide is generated from the organic carbon in the sample liquid by the oxidizing agent in the reaction liquid. The carbon dioxide produced in the reactor 20 is removed by the deaerator 2
Immediately before 0, the strong acid in the reaction solution introduced by the reaction solution supply means 5 is degassed by the deaerator 22. As a result, inorganic carbon and organic carbon (that is, total carbon) are removed from the sample liquid. The gas in the sample solution from which the inorganic carbon and the organic carbon contained in the original sample solution have been removed is measured by the infrared absorption meter 50 via the reactor 36 and the extractor 39. Here, the measurement value measured by the infrared absorptiometer 50 is organic carbon or the like contained in the reaction liquid supplied from the container 6 through the channel 9, and should be canceled as a blank value (system blank) at the analysis point. It is a measured value.

(3) For the calculation means 53, the measurement value measured by the infrared absorption meter 49 of the first system 100,
The measurement value measured by the infrared absorption meter 50 of the second system is supplied to the calculation means 53 together with the measurement value measured by the infrared absorption meter 49, and the measurement value measured by the infrared absorption meter 50 is calculated by the calculation means 53. By subtracting, the organic carbon concentration in the sample liquid is calculated. That is, in the carbon content measuring device of the present invention, the measurement value of the infrared absorption meter 50 of the second system 101, which is provided in parallel with the first system 100, may be used as the reference value for zero point adjustment. By this, elements other than inorganic carbon and organic carbon in the sample solution (for example, the amount of the sample solution supplied, the amount of organic carbon contained in the reaction solution, the degree of influence of moisture interference on the above-mentioned measuring means) Fluctuates, and the infrared absorption meter 4 of the first system 100
Even when the measured value of 9 is affected, the infrared absorption meter 50 in which the sample liquid flows under exactly the same conditions is similarly affected, and the calculation means 53 , The infrared absorption meter 49 of the second system 101 from the measured value by the infrared absorption meter 49 of the first system 100.
These effects can be offset by subtracting the measured value by, and as a result, the effect of accurately measuring the organic carbon in the sample solution can be obtained. In addition,
In this embodiment, the infrared absorptiometers 49 and 50 are individually provided, and the two infrared absorptiometers 49 and 5 are operated by the calculation means 53.
Although the organic carbon in the sample solution is measured by calculating the difference between the measured values depending on 0, the invention is not limited to this. For example, two infrared absorptiometers disclosed in JP-A-2-91569. The use of an infrared gas analyzer that is integrated with allows more accurate measurement of the amount of organic carbon in the sample liquid.

In the above embodiment, the first system 100
In the above, the pipe length adjusting pipe 29 and the overflow passage 35 are provided between the pump 14 and the pump 31, so that the analysis conditions of the first system 100 and the second system 101 are set to be the same. However, the present invention is not limited to this, and in order to bring the measurement conditions of the second system 101 closer to each other, a reaction similar to that of the second system 101 is performed between the pump 14 and the pump 31, as shown in FIG. The device 20, the cooler 21, and the deaerator 22 may be provided in order.

Further, as shown in FIG. 2, when the carbon amount measuring apparatus is constructed by providing the reactor 20 and the deaerator 22 in the first system 100 as in the second system 101, the first system is used. 1
The sample liquid is heated in the reactor 20 of No. 00, carbon dioxide is generated from the organic carbon in the sample liquid by the oxidizing agent in the reaction liquid at this time, and this carbon dioxide can be removed by the deaerator 22. . In this case, in the first system 100, the sample liquid having a zero carbon content contained in the sample liquid is measured by the infrared absorptiometer 49, and in the second system 101, the reaction liquid is added to the sample water having a zero carbon content. The liquid in which the reaction liquid supplied by the supply means 5 is mixed is measured by the infrared absorption meter 50. As a result, it is possible to measure the influence of the reaction liquid added to the sample liquid on the measured values by the infrared absorptiometers 49 and 50. Specifically, the infrared absorption meter 50
The value obtained by subtracting the value measured by the infrared absorptiometer 49 from the value measured by the above is the influence value on the measured value by the reaction solution. Therefore, if the infrared absorptiometers 49 and 50 and the calculating means 53 are adjusted so as to cancel this influence value, the measured value of the amount of organic carbon in the sample solution by the reaction solution becomes more accurate.
In addition, during the normal measurement, the reactor 20 and the deaerator 22 of the first system 100 are not used, and the same measurement method as that of the embodiment of FIG. 1 is performed.

[0024]

As described in detail above, according to the present invention, the second system, which is provided in parallel with the first system, can be used as a system for adjusting the zero point. Elements other than inorganic carbon and organic carbon in the liquid (for example,
The amount of sample liquid supplied, the amount of organic carbon contained in the reaction liquid,
Even if the above-mentioned influence of moisture interference on the measuring means is varied to affect the first system, the second system is also affected accordingly. These effects can be offset by the organic carbon amount calculation means, and as a result, the effect of accurately measuring the organic carbon in the sample liquid can be obtained.

[Brief description of drawings]

FIG. 1 is a piping diagram showing an embodiment of the present invention.

FIG. 2 is a piping diagram showing another embodiment of FIG.

[Explanation of symbols]

 7 Flow Path (First and Second Supply Means) 8 Pump (First and Second Supply Means) 9 Flow Path (Second Supply Means) 10 Pump (Second Supply Means) 53 Calculation Means (Carbon Quantity calculation means) 100 First system 101 Second system

Claims (1)

[Claims] 1. A first supply means for supplying an acidic solution and an oxidant to a sample solution, wherein an inert gas is sent to the sample solution, and the acidic solution supplied by the first supply means The inorganic carbon in the sample solution is removed by the active gas, and then the sample solution is heated to react the organic carbon in the sample solution with the oxidant supplied from the first supply means to obtain a sample. First to generate carbon dioxide from organic carbon in liquid
And a second supply means for supplying an acidic solution and an oxidizing agent to the same sample solution as the sample solution of the first system, and heating the sample solution to remove organic carbon in the sample solution. By reacting with the oxidizing agent supplied from the second supply means, carbon dioxide is generated from the organic carbon in the sample solution, and an inert gas is added to the sample solution containing inorganic carbon such as carbon dioxide. Send
A second system for removing the inorganic carbon in the sample solution by the acidic solution and the inert gas supplied from the second supply means; and a gas contained in the sample solution via the first system. A carbon amount comprising: an organic carbon amount calculation means for obtaining the amount of organic carbon contained in the sample liquid of the first system by comparing with the gas contained in the sample liquid that has passed through the second system. measuring device.