METHOD FOR OBTAINING COAL FROM SOFT WOOD Russian patent published in 2023 - IPC C10L5/00 C10L5/44 

FIELD: solid fuel.

SUBSTANCE: method for producing coal from softwood is proposed, characterized by grinding the raw materials, drying and using pyrolysis on sawdust after drying then cooling the resulting coal, characterized in that the grinding of the feedstock is carried out to a heterogeneous fraction size from 2 to 12 mm, the drying of the resulting sawdust is carried out by zone at a temperature of 400°C with its exponential rise to 600°C in a wind tunnel made in the form of a spiral, equipped with a moisture meter with the ability to measure the moisture content of the sawdust and control the temperatures of the zones based on the moisture content of the sawdust, the sawdust obtained after drying is fed to a briquette press, where, simultaneously with pressing, the sawdust is affected by ultrasonic vibrations using an ultrasonic resonator, facilitating formation of a homogeneous structure of a wood briquette, the compressed briquette is sawn into pieces and fed into a thermosetting conveyor for differentiated pyrolysis based on the phased thermal decomposition of biomass, in the first zone of the pyrolysis conveyor the briquette is heated to 200°C to exclude temperature fluctuations and cracking of the wood briquette, in the second zone the briquette is heated up to 280°C to prepare for the exothermic process of charcoal, in the third zone, the briquette is heated to 500°C to maintain the exothermic process, in the fourth zone, the briquette is cooled in a natural oven to 300°C, after which it is further cooled with simultaneous stabilization in a nitrogen environment with the possibility of neutralizing free radicals and reducing the reactivity of the charcoal briquette.

EFFECT: providing the possibility of obtaining coal from soft wood with high consumer properties.

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