Comparative infra-red spectra, ultimate analyses and yields of γ-fractions, pyridine- or chloroform-extracts, from a Japanese caking coal and the same coal preheated at 250, 300, 350, 400 and 450 °C, have been examined. It is deduced that: 1. (1) the extracts from samples of this coal preheated below 350 °C do not appear to contain thermal decomposition products 2. (2) the increase in yield of extract by preheating may depend on the exudation of chloroform-soluble and other material from inside the coal 3. (3) the higher the preheating temperature, the larger the exudation, but on the other hand the evaporation of extract and its decomposition increase rapidly above 400 °C, and together result in the rapid decrease of extraction yield. Based on the above deduction, it is concluded that the maximum extraction yield at a certain preheating temperature may appear by the mutual relation of exudation, evaporation and decomposition at the corresponding temperature.
ASJC Scopus subject areas
- Chemical Engineering(all)
- Fuel Technology
- Energy Engineering and Power Technology
- Organic Chemistry