JP5228144B2 - Low temperature combustion analysis and measurement system using metal catalyst effect - Google Patents

Description

  The present invention is an organic element analyzer for quantifying carbon, hydrogen, nitrogen, halogen, sulfur in solid or liquid samples, organic carbon contained in waste water, environmental water, TOC (total organic carbon) meter for analyzing nitrogen, The present invention relates to a technique for oxidizing and decomposing organic substances in a sample in various analyzers of a TN meter.

  Conventionally, the contents of C, H, N, halogen and sulfur in the sample are from 850 ° C. to 1000 ° C. by combustion decomposition in an electric furnace, and a gas obtained by thermal conductivity detector, infrared detector, titration method, ion chromatography Quantify by the detection method of each element by the graph method. On the other hand, in the case of a TOC (total organic carbon) meter, in addition to burning at a high temperature of 850 ° C. to 1000 ° C. as described above, it is burned by a platinum catalyst at 680 ° C., decomposed by contact with a photocatalyst and irradiation with ultraviolet rays. The method is taken. The former measures the weight of the sample accurately and measures the content w / w% with respect to the weight of each element. In the industry, including the determination of the structure of pharmaceuticals, petroleum, coal, cement, rock, carbide Widely used in various fields such as tobacco, beer, glass fiber, plastic, metal catalyst, bio-material waste incineration facility. The latter is intended for the determination of carbon and nitrogen in various environmental samples, and is used in many fields such as the environment, automobiles, agriculture, forestry, marine research, and food.

  A quartz combustion tube is installed in the electric furnace, and the inside is filled with copper oxide and other reagents effective for combustion, but since it is kept at a high temperature for a long time, quartz damage and consumption of the filler in the combustion tube are reduced. Some are violently improved to ceramics or metal, but they are expensive.

  Moreover, in an organic element analyzer and a CN meter, it is necessary to reduce the N oxide generated by combustion for N component determination, and a separate electric furnace filled with reduced copper that can be set to 500 to 600 ° C. is used.

  FIG. 1 shows a structure of an organic element analyzer that is generally used as an example of an electric furnace of a conventional analyzer, and shows a combustion process and a state of filling in a combustion tube.

1. High purity helium as a carrier gas is opened at a constant speed by opening the electromagnetic valve 7a.
2. Use a micro balance to accurately weigh the sample.
3. The sample compound is completely burned into a gas in a quartz combustion tube 4 filled with copper oxide in a decomposition furnace 1 at 950 ° C. and an oxidation furnace 2 at 850 ° C. At this time, about 10% of pure oxygen of the carrier gas flows into the combustion pipe. In this process, carbon becomes CO ₂ , nitrogen becomes NO ₂ , and hydrogen becomes H ₂ O. NO ₂ is reduced to N ₂ by the reduced copper filled in the quartz reduction tube 5 in the next reduction furnace 3. Excess oxygen is also removed as copper oxide by reduced copper in the reducing tube. If the sample contains halogen and sulfur, they are trapped as silver halide and silver sulfide respectively by the silver grains filled at the tip of the reduction tube.
4). The remaining gas is a mixed gas of CO ₂ , N ₂ , H ₂ O, and carrier gas.
5. After feeding and diluting the metal pump 8 with a capacity of 150 ml with the carrier gas, the mixed combustion gas is sent to the measurement system at a constant flow rate.
6). The mixed gas is sequentially passed through the three TCD detectors 9a, 9b, and 9c to detect the respective concentrations with electric signals, and the electric signals are processed by the signal processing means and output as count values count.
7). The mixed gas first passes through the absorption tube 10 filled with the H ₂ O absorbent, and H ₂ O is removed. The difference in resistance value between the measurement cells before and after that is converted into the count value count by the method described above.
8). Next, the remaining gas mixture passes through an absorption tube 11 filled with a CO ₂ absorbent, and CO ₂ is removed. The difference between the resistance values before and after is converted into the count value count in the same manner.
9. Finally, the difference between the resistance value of the remaining gas N _{2 and} the resistance value of the carrier gas reserved in the delay coil 12 is similarly converted to the count value count.
10. The atmospheric pressure correction on the day of measurement is performed for the above count value count. This corrects the atmospheric pressure by the mole fraction of gas in the detector.
11. The sensitivity coefficient (μg / count) for each CH N element is determined using a standard sample for elemental analysis whose CHN content (w / w%) is known in advance. The CHN content (w / w%) of the unknown sample compound is calculated using the determined sensitivity coefficient (μg / count) or factor.
12 Elemental analysis values are displayed as C: □%, H: □%, N: □%.

Description of the arithmetic processing method in the above measurement is omitted.

        JP 2006-258619A (P2006-258619A)

CHN coder's face Supervised by Keiichiro Hozumi Edited by Yanaco Analytical Co., Ltd. Technical Group 1993 Not for Sale

  Since the organic element analyzer of the prior art has a high temperature furnace and a large increase in room temperature, it is necessary to constantly adjust the measurement environment with an air conditioner. Calibration curve preparation and sample measurement must be performed under the same environmental conditions.

In addition, the TOC and TN analyzers of the prior art are completely burned in a temperature environment of 900 ° C. When inorganic salts are contained in the sample, interfering gas or mist containing chlorine is generated, and a normal CO ₂ peak and a part of it are generated. Overlapping causes an abnormal peak or greatly changes the baseline. In addition, since a highly corrosive molten salt is generated, the filler such as a catalyst and an absorbent in the combustion pipe and subsequent pipes is corroded and contaminated. In order to maintain the combustion tube at a high temperature, the load of the heater and heat insulating material constituting the electric furnace is large, the durability is lowered, and the power consumption is the same as in the elemental analyzer. Although there is a method of burning with a platinum catalyst at 680 ° C. which improves this point, it has the same problem regarding the electric consumption. Furthermore, there is a method of decomposing by contacting with a photocatalyst and irradiating with ultraviolet rays. However, since the oxidizing ability is lower than that of the combustion type, analysis takes a long time. There are complex drawbacks of labor and maintenance.

  The present invention solves the unreasonableness of the various analyzers due to the combustion method, constitutes a small and energy-saving simple system, and is a power-saving type that society currently needs by a sustainable design concept including use to disposal It is intended to be developed as an environmentally friendly and efficient analyzer and spread to the industry.

In a first invention for solving the above object, a combustion tube filled with titanium oxide granules or powdered titanium oxide is used. In an analytical measurement system for burning a sample to determine the content of a predetermined element selected from carbon, hydrogen, nitrogen, halogen and sulfur contained in the sample, a combustion tube for storing the sample;
A combustion furnace for heating the sample stored in the combustion tube;
Having a calculation means for obtaining a necessary measurement value from the content (μg), content% and content ratio of the predetermined element from the gas generated from the sample heated in the combustion furnace,
The combustion tube is filled with titanium oxide,
The combustion furnace heats a sample stored in the combustion tube to 400 ° C. or more and 650 ° C. or less.

A second invention for solving the above object is an analytical measurement system for determining the content of a predetermined element selected from carbon, hydrogen, nitrogen, halogen and sulfur contained in the sample by burning the sample.
A combustion tube for storing the sample;
A combustion furnace for heating the sample stored in the combustion tube;
Having a calculation means for obtaining a necessary measurement value from the content (μg), content% and content ratio of the predetermined element from the gas generated from the sample heated in the combustion furnace,
The combustion tube stores a sample to which titanium oxide is added, and the combustion furnace heats the sample stored in the combustion tube to 400 ° C. or more and 650 ° C. or less.

A third invention for solving the above object is an analytical measurement system for determining the content of a predetermined element selected from carbon, hydrogen, nitrogen, halogen and sulfur contained in the sample by burning the sample.
A combustion tube for storing the sample;
A combustion furnace for heating the sample stored in the combustion tube;
Having a calculation means for obtaining a necessary measurement value from the content (μg), content% and content ratio of the predetermined element from the gas generated from the sample heated in the combustion furnace,
The combustion tube contains a sample placed on a combustion boat coated with titanium oxide,
The combustion furnace heats a sample stored in the combustion tube to 400 ° C. or more and 650 ° C. or less.

A fourth invention for solving the above object is an analytical measurement system for determining the content of a predetermined element selected from carbon, hydrogen, nitrogen, halogen and sulfur contained in the sample by burning the sample.
A combustion tube for storing the sample;
A combustion furnace for heating the sample stored in the combustion tube;
Having a calculation means for obtaining a necessary measurement value from the content (μg), content% and content ratio of the predetermined element from the gas generated from the sample heated in the combustion furnace,
When the sample contains nitrogen, the combustion tube fills and stores reduced copper after the titanium oxide layer, and the combustion furnace stores the sample stored in the combustion tube at 400 ° C. or higher and 650 ° C. The following is heated. In the combustion pipe, NO ₂ generated by the titanium oxide layer is subsequently reduced to N ₂ in the reduced copper filling portion.

  The organic element analyzer required decomposition in a high-temperature furnace in order to deal with any sample, but because the sample can be decomposed at low temperatures by using the catalytic ability of titanium oxide, radiant heat has so far been designed by the high-temperature furnace design. Therefore, it is possible to easily reduce the size which is the object of the present invention.

  Furthermore, by setting the furnace temperature to 400-650 ° C., the analyzer can be oxidized and reduced simultaneously in a single combustion tube, eliminating the need for a conventional reducing furnace and simplifying the structure of the analyzer. Since this principle can also be applied to TOC meters and TN meters, the combustion analyzer is reduced in size in conjunction with the above items, reducing the load on energy by means of transportation, and in the case of disposal, the conventional one Can be reduced to 1/5.

It is a combustion system block diagram of a conventional organic element analyzer It is a block diagram of the combustion system which implements this invention. (Example) It is an analysis process flowchart in the present invention. (Example)

  The present invention is characterized in that combustion decomposition of a sample is performed at 400 ° C. or higher and −650 ° C. or lower using the catalytic effect of titanium oxide. There are three ways to use it:

A combustion tube is filled with granular titanium oxide or powdered titanium oxide encased in a carrier. Add an appropriate amount of powdered titanium oxide to the boat for combustion. Alternatively, titanium oxide is applied to the inner surface of the combustion boat.

Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 to 3, but the present invention is not limited to these examples.

A conventional combustion system is shown in FIG. 1 for comparison with the combustion system of the present invention. A high temperature combustion furnace at 950 ° C., an oxidation furnace at 850 ° C., and a reduction furnace at 550 ° C. for reducing nitrogen oxides are required. FIG. 2 is a block diagram of a combustion system for carrying out the present invention, which is composed of one combustion furnace.
The combustion tube may be made of hard glass, ceramic, or other metal. The sample is decomposed by a combustion system using the catalytic effect of titanium oxide.

  In the present invention, CHN and XS may be the same combustion system, but carbon, nitrogen, and hydrogen elements are detected by a TCD method or an infrared detector, and halogen and sulfur elements are quantified by titration or ion chromatography.

  FIG. 3 is a flowchart for explaining the measurement process in the present invention. The flow of a decomposition product from the generated combustion gas to each detection process is shown by feeding a sample into the combustion system.

According to the combustion system of the present invention, the combustion furnace of the organic element analyzer is set to 400 ° C. to 650 ° C., the combustion tube is filled with titanium oxide, and subsequently reduced copper is packed, and various organic element analysis standard samples (manufactured by Kishida) are used. The experiment was conducted using The measurement results by this combustion system are shown below.
(Experiment)

The results of the analysis using each standard sample shown in Table 1 were generally within the measurement accuracy (allowable error 0.3%) of elemental analysis. The measurement error of the content (μg) of each element was accurately measured in the range of H (0.1 to 1.2 μg) C (0.1 to 4.3 μg) N (0 to 4.2 μg). In this experiment, the content of each element in the sample is precisely detected in μg units.

Table 2 shows the accuracy of the repetition. The calibration standard sample Antitiprine, which is generally used for elemental analysis, was tested with an extremely small amount of 0.5 mg. As a result, each standard deviation was H: σ = 0.91% C: σ = 0.20% N: σ = 0.12%, and H had a slightly large error due to adsorption, but CN had a sufficiently good result.

  Furthermore, as a result of experiments with 500 μg and 300 μg of ultra-trace amount using Dioctadecylamine N = 2.68%, which is a commercially available reagent, both are within element analysis tolerance ± 0.3%, and the absolute content is 16 ± 1.6 μg, 8.3 ± 0.4 μg Met. The results are shown in Table 3.

  The method of the present invention can accurately measure the content of carbon, nitrogen, chlorine, bromine, iodine, and sulfur in μg units, and is particularly effective for environmental measurement for preventing global warming. The C / N value is measured to investigate the elemental composition (the proportion of carbon, hydrogen, and nitrogen) of flammable components in garbage, and to stabilize and control the HTGR during incineration. It can be used in a wide range of fields such as the measurement of the molar ratio of hydrogen to carbon in the environment and the use of environmental fields such as measurement for water purification, as well as food raw materials, petroleum, coal, and marine suspended matter.

  Further, the combustion analyzer according to the present invention can be expected to spread including overseas as a popular apparatus that is easy to move and use. In addition, it is used for agriculture, livestock industry, forestry, biofuels, etc., and is a quality display item especially for compost, and is an effective measuring instrument for promoting improvement in the field of agriculture and livestock industry. In addition, TOC meters are used for water quality management (tap water, ultra-pure, drainage, pool water, spring water, bath water, boiler water), pharmaceutical manufacturing, quality control, process management, research, research (global environment, eutrophication) TN meter is also used in many fields such as factories and automobile exhaust.

  The method of the present invention that can prove the accurate measurement of the absolute content in a sample can be established by an analytical system that can verify the calculation process based on the reliability of automatic balance output, standard sample quality assurance, and automatic instrument signal output. It can provide accurate measurement values for each environmental standard and evaluation. In particular, as a measure against global warming and environmental pollution, the behavior of carbon and nitrogen is an important index, and there is no other means of this accuracy that can detect minute changes. The significance of the application of this combustion system to those analyzers is that it can be expected to have a very wide spread related to most domestic and foreign industries.

1. Sample decomposition furnace 2. Oxidation furnace 3. Reduction furnace 4. Quartz combustion tube 5. Quartz reduction tube 6. Sample introduction rod 7a-d. Electromagnetic valve 8. Pump 9a-c. TCD detector 10. H ₂ O absorption tube 11. CO ₂ absorption tube 12. Delay coil

Claims (4)

In an analytical measurement system for determining the content of a predetermined element selected from carbon, hydrogen, nitrogen, halogen and sulfur contained in the sample by burning the sample,
A combustion tube for storing the sample;
A combustion furnace for heating the sample stored in the combustion tube;
The content of the predetermined element from the gas generated from the heated in the combustion furnace sample ([mu] g), a content% and containing ratio, or calculating means for determining the one,
The combustion tube is filled with a filling containing titanium oxide,
The analytical measurement system characterized in that the combustion furnace heats a sample stored in the combustion tube to 400 ° C. or higher and 650 ° C. or lower. In an analytical measurement system for determining the content of a predetermined element selected from carbon, hydrogen, nitrogen, halogen and sulfur contained in the sample by burning the sample,
A combustion tube for storing the sample;
A combustion furnace for heating the sample stored in the combustion tube;
The content of the predetermined element from the gas generated from the heated in the combustion furnace sample ([mu] g), a content% and containing ratio, or calculating means for determining the one,
The combustion tube stores a sample to which titanium oxide is added, and the combustion furnace heats the sample stored in the combustion tube to 400 ° C. or higher and 650 ° C. or lower. system. In an analytical measurement system for determining the content of a predetermined element selected from carbon, hydrogen, nitrogen, halogen and sulfur contained in the sample by burning the sample,
A combustion tube for storing the sample;
A combustion furnace for heating the sample stored in the combustion tube;
The content of the predetermined element from the gas generated from the heated in the combustion furnace sample ([mu] g), a content% and containing ratio, or calculating means for determining the one,
The combustion tube contains a sample placed on a combustion boat coated with titanium oxide,
The analytical measurement system characterized in that the combustion furnace heats a sample stored in the combustion tube to 400 ° C. or higher and 650 ° C. or lower. In an analytical measurement system for determining the content of a predetermined element selected from carbon, hydrogen, nitrogen, halogen and sulfur contained in the sample by burning the sample,
A combustion tube for storing the sample;
A combustion furnace for heating the sample stored in the combustion tube;
The content of the predetermined element from the gas generated from the heated in the combustion furnace sample ([mu] g), a content% and containing ratio, or calculating means for determining the one,
When the sample contains nitrogen, the combustion tube is filled with reduced copper following a packing layer containing titanium oxide and stored.
The analytical measurement system characterized in that the combustion furnace heats a sample stored in the combustion tube to 400 ° C. or higher and 650 ° C. or lower.

Images