Exothermic effect during torrefaction

There are presented the results of investigation of exothermal effect taking place during torrefaction process. Experiments were carried out with the help of thermoanalyzer SDT Q600, that gives opportunity to use methods of differential thermogravimetric analysis and differential scanning calorimetry, and at the lab-scale installation modelling the column-type torrefaction reactor with indirect (through the wall) heating of processable raw material. It was ascertained the correspondence between the processes of thermal decomposition of basic organic components of wood (hemicellulose, cellulose and lignin) and the characteristic endo- and exothermic peaks on the curve of effective heat capacity. It was shown that the exothermal effect accompanying thermal decomposition of hemicellulose, taking place during torrefaction, may lead to spontaneous heating of wood biomass to temperatures significantly exceeding the wall temperature.