The vapor pressure of Se and SeO2 measurement using thermogravimetric analysis

Abstract

The vapor pressure data of Se and SeO2 in low temperature range are essential for the study of emission and migration of selenium from stationary sources. The vapor pressure of SeO2 at 353.2–473.2 K was measured by thermogravimetric analysis, and the corresponding pressure was 0.026–319.2 Pa. The vapor pressure of Se at 423.2–573.2 K was measured, and the corresponding pressure was 0.007–80.9 Pa. The triple point temperature and pressure of Se determined in this experiment were 491.2 ± 1 K and 2.16 ± 0.27 Pa. The extended uncertainty of temperature measurement (k = 2) was 1.86 K, and the extended relative uncertainty of pressure measurement (k = 2) was 0.128p. The vapor pressures of Se and SeO2 were fitted to Antonie equation, respectively, and compared with the available literature data.