SU1180793A1 - Method of determining concentration of organic gas in gas mixture - Google Patents

Abstract

METHOD OF DETERMINATION IN A GAS MIXTURE OF ORGANIC GAS CONCENTRATION, including cleaning the mixture from extraneous analyzed gases and passing the resulting gas mixture through a liquid, characterized in that, in order to accelerate the analysis and increase its accuracy in |, the volumes of the mixture under study use liquid as a liquid through which one bubble is passed and the rate of its rise is measured with the subsequent determination of gas concentration according to the graph of the dependence of gas concentration on the speed of bubble rise. cl

Description

00

The invention relates to the field of physico-chemical measurements and can be used in studies in the field of studying the physical properties of volatile organic compounds, controlling gas cleaning processes from volatile organic compounds and in other processes where it is necessary to determine the concentration of organic substances in the gas phase. The purpose of the invention is to accelerate the analysis and increase its accuracy with small volumes of the test mixture. The goal is achieved by varying the speed of movement of a bubble of sample gas in distilled water. The greater the concentration of organic matter in the gas sample being studied, the slower the bubble movement. Measuring the dependence of the speed of movement of bubbles in distilled water on the concentration of opratoi4ecKoro substance in the gas phase of a bubble and plotting a calibration curve, according to experimental data on the speed of movement of bubbles, the concentration of the substance contained in the gas sample is determined or, if necessary, to solve the issue of purity organic matter, determine the differences in the speed of movement of bubbles of clean and agglomerated air and make a conclusion about its purity. The proposed method is not suitable l accurately determine in each individual component when present in the sample not one but several organic substances. In the case when various organic substances are contained in the gas sample, which have the same or similar effect on the velocity of the bubble, the proposed method is suitable for determining the total concentration with the construction of a corresponding calibration curve. The table shows the results of the determination of organic substances contained in the gas phase by the proposed and known methods. From the table it follows that the proposed method requires significantly less analysis time, and in addition, it can be carried out with much less. compared to the known, the volume of gas samples. Example 1 Distilled water, previously aspirated with air, is placed in a glass tube with a diameter of 5 cm and a height of 1 m and air bubbles with a diameter of 7 mm, containing cyclohexanol, are passed through it. The rate of their rise is measured. Then, using the previously constructed calibration curve (with puzzles of the same size) in coordinates — bubble velocity-content of cyclohexanol in the gas phase — determine the concentration of cyclohexanol in the gas sample. EXAMPLE 2 Distilled water, previously saturated with air, is placed in a glass tube 3 cm in diameter and 1 m in height and bubbles of an analyzed air sample of 0.7 mm in diameter containing hexane are passed through it. The rate of their rise is measured. Then, according to the previously constructed calibration curve (with bubbles of the same size) in coordinates: dinata velocity of the bubble — concentration of hexane in the gas phase — the concentration of hexane in the air sample is determined. Example 3. Distilled water, pre-saturated with air, is placed in a glass tube with a diameter of 1.5 cm and a height of 50 cm and pass through it bubbles of the analyzed air sample with a diameter of 0.9 mm containing acetylene. The rate of their rise is measured. Then, using the previously constructed calibration curve (with bubbles of the same size) in coordinates — bubble velocity — acetylene concentration in the gas phase — determine the acetylene concentration in the air sample. Example 4. Distilled water, previously aspirated with air, is placed in a glass tube with a diameter of 1.5 cm and a height of 50 cm and the bubbles of an analyzed air sample with a diameter of 0.7 mm containing a mixture of decane and dodecane (which have a similar inhibitory effect) are passed through it. on the speed of bubbling up). The rate of their rise is measured. Then, according to the previously constructed calibration curve (with bubbles of the same size) in the coordinates - velocity

kana in gas phase is determined.

dean in the air sample.

95.0

50

Cyclohexonol 98.0

101.0 99.0

101.0

50

Known - Cyclohex NOL

25,

123.0

Cyclohexonol 122.0. . 124.0 126.0 126.0

25

Known - Cyclohex NOL

- Table continuation

Claims (1)

METHOD FOR DETERMINING AN ORGANIC GAS CONCENTRATION IN A GAS MIXTURE, including cleaning the mixture of extraneous analyzed gases and passing the resulting gas mixture through a liquid, characterized in that, in order to accelerate the analysis and increase its accuracy for> small volumes of the test mixture, they use water through which one bubble <is passed and the rate of its rise is measured with subsequent determination of the gas concentration according to the graph of the dependence of the gas concentration on the velocity <g of the bubble rise. 00 about m CD With