SU1499200A1 - Method of preparing gas mixtures with given content of oxygen - Google Patents

Abstract

The invention can be used for metrological provision of gas analytical devices that measure micro and ultra low oxygen contents in hydrogen and hydrogen containing gases. The purpose of the invention is to expand the range of prepared calibration gas mixtures in the direction of low oxygen content while increasing the accuracy of its analysis. The method is based on the dosing of oxygen from atmospheric air into a stream of gas previously purified from moisture and oxygen using a high-temperature solid electrolyte cell at a heating temperature of 750–900 ° C, chemical transformation of dosing oxygen with hydrogen into a solid electrolyte cell into water, subsequent continuous its electrolytic decomposition into hydrogen and oxygen in the coulometric cell and the separation of the latter into a gas stream. The dosing of oxygen and the electrolysis of water are carried out at equal values of the dosing current and the electrolysis current, the ratio of the amount of oxygen being metered and the amount of water being simultaneously electrolyzed is continuously kept constant in accordance with the stoichiometry of the hydrogen oxidation equation, and the excess water is passed through the coulometric cell and dried. 1 il.

Description

one

(21) 4201175 / 24-25

(22) 02.24.87

(46) 07.08.89.BUL Number 29

(72) V.I. Smirnov., V.M.Sopov,

L.F.Nosenko and S.B.Meshkov

(53) 543.247 (088.8)

(56) Patrushev Yu.N., Pinkusovich R.L. et al. Method of dosing oxygen into gaseous media using solid electrolyte cells. - Automation of chemical production. 1973, No. 3.

Smirnov V.I. et al. Report at the 2nd All-Union Symposium Solid electrolytes and their analytical application. - Sverdlovsk, 1975.c.97.

(54) METHOD FOR PREPARING GOVERNMENT FOR GAS MIXTURES WITH THE SPECIFIED CONTENT OF OXYGEN

(57) The invention can be used for metrological provision of gas analytical devices that measure micro and ultra low oxygen contents in hydrogen and hydrogen containing gases. The purpose of the invention is to expand the range of prepared calibration gas

mixtures in the direction of low oxygen content while improving the accuracy of its analysis. The way is based on; dosing oxygen from atmospheric air into a stream of gas previously purified from moisture and oxygen by means of a high-temperature solid electrolyte cell at a heating temperature of 750–900 ° C, chemical transformation into water of doped oxygen with hydrogen in a solid electrolyte cell, followed by continuous continuous extraction of this water and simultaneously electrolytically decomposing it into hydrogen and oxygen in the coulometric cell and releasing the latter into the gas stream. The dosing of oxygen and the electrolysis of water are carried out at equal values of the dosing current and the electrolysis current, the ratio of the amount of oxygen being metered and the amount of water being simultaneously electrolyzed: continuously maintained constant in accordance with the stoichiometry of the hydrogen oxidation equation, and the excess water is passed through a culture meter. the cell and drain. 1 Il.

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The invention relates to a measurement technique and is intended for the metrological provision of gas analysis devices that measure micro and ultra low oxygen contents in hydrogen and hydrogen containing gases with a hydrogen content that is at least twice the oxygen content.

The purpose of the invention is the expansion of the range of prepared calibration gas mixtures (CBC) in the direction of low oxygen contents and increasing the accuracy of the analysis.

The drawing shows a diagram of the device that implements the proposed method.

31A99

The device contains a reactor 1, desiccant 2 ,. solid electrolyte cell (TEL) 3 and coulometric cell (QW) 4J installed in the circuit sequentially along the gas mixture, current generator 5 connected electrically in series with the thermoelectric cell electrode 3 and QW 4 and current meter 6, dryer 7 ,. installed by the latest at the outlet of the gas mixture, the QW 8 and the power source 9. With this, the TEY and QW have a common serial electrical supply circuit.

Example. Hydrogen or hydrogen-containing gas mixture with a hydrogen content by volume exceeding not less than 2 times the oxygen content is continuously supplied with a constant flow rate, for example, 500 cm / min to the input of the reactor 1. Maintaining a constant gas flow rate of dry using a gas flow stabilizer (not shown). In the reactor 1, a trace of oxygen present in the gas mixture interacts with hydrogen to form water. The gas mixture with the water formed, the passage through the drying device 2, is dried and then flows successively into the gas channel of the SED 3, which is at a heating temperature of 450-650 C, and KW4. With the help of the current generator 5, the oxygen metering current from the atmospheric air is set ha with the simultaneous chemical transformation of the prodded oxygen and hydrogen of the gas mixture into iRDU in TED 3, while at the same time in QW 4 it is continuous - its electrolysis is carried out. Since the electrodes of TAYN 3 and QW 4 are electrically interconnected and to the current generator 5 in series, the metering current I and the electrolysis current 1, measured by the current meter 6, are always equal. Thus, using the current generator 5, it is possible to regulate the electrolysis process, namely, to subject to electrolytic decomposition such amount of water, which by the stoichiometric equation of hydrogen oxidation exactly corresponds to the specified oxygen content in the calibration gas mixture at a given

its expense. Excess water, the presence of gas and the mixture, passing through the QW A, is removed in the dryer 7. The need for the last operation is related to the principle of operation of most existing oxygen analyzers in hydrogen and hydrogen-containing gases. These gas analyzers normally work on the analyzed gases with limited water content. For example, for a Garnet gas analyzer, the water content in the analyzed fa3e should not be more than 2 million, and Amethyst should be 1 million because for them water is a component that worsens their metrological characteristics, in particular, the error.

Claims (1)

Invention Formula The method of preparation of calibration gas mixtures with a given oxygen content by electrochemical dosing of oxygen from atmospheric air into a stream of gas previously cleaned from moisture and oxygen using a high-temperature solid electrolyte cell (SED) at a heating temperature of 750-900 s, chemical conversion into water of oxygen-charged oxygen with hydrogen in the SEC, the subsequent uninterrupted extraction of this water from the gas mixture with simultaneous electrolytic decomposition in the coulometric cell (QW) n hydrogen and oxygen and the latter are introduced into the gas stream, which is characterized by the fact that, with the aim of expanding the range of the prepared PGM towards lower oxygen contents and accuracy of analysis, oxygen dosing and electrolysis of water are carried out at equal dosing current values and the current of electrolysis, the ratios of the amount of oxygen being metered and the amount of water simultaneously subjected to electrolysis are continuously kept constant in accordance with the stoichiometry of the hydrogen oxidation equation, and the excess dy pass through the QW and drain. vlod gozo mixes Lsho9 PGS