The reception of products from wood by its exposure to high temperature refers to one of the most ancient technologies in the humankind history. The archeological excavations prove that cavement knew about the charcoal.It was collected at site of fire or made specially by filling up smoldering firebrands with ash and used them as fuel that does not generate coal gas when sheltering from bad weather in caves. The first metal was melted propably accidentally, when stones laid around the fireplace with live coal turned to be ore. Starting from the Bronze Age, the charcoal became one of the grounds...

Absolutely dry wood is almost absent. Wet wood must be dried before its decomposition starts. Until its surface layers are moist, the wood temperature cannot exceed 100 °С, i. e. water boiling point. After the outer layers are dried completely, the wood temperature starts increasing. The wood is composed of several components with different chwmical compositions. First, when the lump surface temperature is approximately 180–200 °С, hemicelluloses start decomposing, which is followed by the cellulose and then lignite decomposition. When the surface temperature is up to 280–290 °С, only small chains forming gases and light liquid products are separated. When...