Abstract
The low rank coal, especially brown coal has a highly hygroscopic and unstable property, so JIS method could not be applied to such a coal.
In direct gravimetric method we found that the cause of difficulity to get constant weight may be attributed to adsorption or desorption of oxygen gas and the passing of the inert gas containg the moisture brings about the activiation ofabsorber which also results the difficulity to get constant weight.
So we have established the improved gravimetric method to get correct value, whichis comprised by two factors, one is passing of the inert gas containing moisture to heated copper oxide zone before the absorption of moisture by absorber, and the other is passing of the dry oxygen gas to absorber to get the constant weight. The sequential analysis of moisture, hydrogen and carbon of browncoal was achieved by this improved method.
In drying method, we established the improved method comprised of using modified apparatus of Abderhalden's drier and introducing helium gas.
