2018 Volume 97 Issue 1 Pages 1-7
This paper considers the possibility of applying indicators of coal as indicators of torrefied biomass characteristics. Used indicators of coal are fuel ratio which shows the combustion characteristics and coal band (van Krevelen diagram) which shows the degree of coalification. Torrefied biomass heated at different temperature are prepared by using green tea. Their changes of fuel ratio and chemical composition by coal band are considered. The results show the following findings. In the heating temperature from 293 K to 640K, fuel ratio is 0.38 to 2.07. There are the each negative correlation between yield of weight and fuel ratio when fuel ratios are a range of 0.38 to 0.65 and more than 0.65. When fuel ratio is 0.65, there is an inflection point. It is suggested that the volatile components released by thermal decomposition are different on the border line of the inflection point. By the application of coal band，chemical reactions are estimated during torrefaction process. However, it is difficult to decide what kind of reactions is occurring when the release of oxygen by decarboxylation and decarbonylation reaction and the release of hydrogen by demethanization and dehydrogenation reaction occur simultaneously.
