CHEMICAL SENSOR FOR MONITORING FIRE- AND EXPLOSION-HAZARDOUS CONCENTRATIONS OF NATURAL GAS
Abstract
Methane explosions remain one of the most hazardous accidents in domestic and industrial facilities. The lower and upper explosive limits of methane are 5% and 16% respectively, which necessitates the development of chemical sensors to ensure explosion and fire safety. In this work, sensitive and selective thermocatalytic and semiconductor methane sensors were developed for natural gas monitoring. The catalytic composition based on 0.75In2O3–0.25Ag2O and 0.25Fe3O4–0.75Ni2O3 was synthesized using sol-gel technology, providing high sensitivity and selectivity towards methane in the presence of CO and H2. Comparative studies conducted in the Gas Analysis Laboratory of Samarkand State University (1990–2019) demonstrated that the newly developed TCS-1 significantly outperforms previously designed analogs (TCS-2 and TCS-3) and commercial sensors in terms of selectivity and response time. The proposed sensors exhibit rapid response characteristics (t0.1 = 3–4 s; tp = 17–18 s) and a linear dependence of output signal on methane concentration in the range of 0.1–5.0% vol. The results confirm the applicability of the developed methane sensors for express control of natural gas concentrations in the atmospheric air of industrial and domestic facilities, as well as in transport cabins, ensuring reliable monitoring of fire- and explosion-hazardous gas levels.
References
1.Glebova E.V., Golubev Yu.D., Prosnurov A.P., Yankovich A.Kh., Kashirskaya L.M. Estimation of air pollution during open sulfur storage // Safe. Labor in industry. 1990.- No. 3. -Pp. 36-37.
2. Bukun N., Dobrovolsky Y., Levchenko A., Leonova L., OsadchiiE. Electrochemical processes of H2S detection in air and solution // Journal of Solid State Electrochemistry, 2003. -№7. –Рp. 122-124.
3. Perekrestov A.P. The effect of hydrogen sulfide on the intensity of corrosion-mechanical wear // Herald of mechanical engineering. 2006.- No. 9. -P.44.
4. Harmful substances in industry. Handbook for chemists, engineers and doctors.L.: Chemistry. 1977. T III. p.5 0-54.
5. Levchenko A., Bukun N., Dobrovolsky Yu., Leonova L., Mazo G. Effect of NaxWO3 composition on electrochemical properties of boundaries with NASICON as solid electrolyte // 14 th International Conference on Solid State Ionics. -Monterey, California U.S.A., 2003. -P. 7.
6.AbdurakhmanovE., DaminovG.N., SultanovМ.М., TillayevS.U.Ensuring the selectivity of the thermocatalytic sensor of exhaust gas components // Ecological systems and devices. –М., 2008. –No.5. -p.30-32.
