METHOD AND SYSTEM FOR LOW-ENERGY BIOMASS TORREFACTION Russian patent published in 2019 - IPC C10L9/08 C10B49/02 C10B53/02 F23B10/00 F23B80/00 

FIELD: technological processes.

SUBSTANCE: invention relates to method and system for torrefaction of biomass and combustion of generated glowing gases. Method of torrefaction of biomass and combustion of generated torrefaction gases includes the following steps: a) torrefaction of possibly pre-dried biomass in a torrefaction reactor to obtain torefied biomass and torrefaction gases, b) draining the torrefaction gases from the torrefaction reactor by low pressure generated by the primary air flow flowing through the ejector burner and into the first combustion zone, c) passing the secondary air flow to the first combustion zone for at least partial combustion of the exhausted torrefaction gases to obtain hot exhaust gases, d) separating hot exhaust gases obtained at step (c) into a first stream of hot exhaust gases and a second stream of hot exhaust gases by discharging a first stream of hot exhaust gases from a first combustion zone to a gas mixing unit, e) diverting a second stream of hot gases into second combustion zone, f) passing a tertiary air flow, stoichiometric or super stoichiometric oxygen content, to a second combustion zone for additional combustion of the second stream of hot exhaust gases to produce a stream of additional combustion gases subjected to additional combustion, g) diverting the stream of combustion gases subjected to additional combustion into a heat recovery unit, in which reducing the temperature of the stream of additional exhaust gases, which are subjected to additional combustion, obtained at step (f), to obtain a stream of cold off-gases, h) withdrawing part of the cold exhaust gases obtained at step (g), into gas mixing unit, so that cold waste gases flow is mixed with first flow of hot exhaust gases to produce stream of partially cooled exhaust gases, i) flow of partially cooled exhaust gases, obtained at stage (h), into torrefaction reactor, so that it is possible to pre-dried biomass comes into direct contact with said flow of partially cooled exhaust gases, so that it is possible to pre-dried biomass is heated directly using a stream of partially cooled off-gases. Also disclosed is a system according to the method.

EFFECT: method and system with low power consumption.

15 cl, 2 dwg