Thermal Analysis of Granular Biofuel Torified in the Atmosphere of Its Own Gaseous Environment

Abstract

The article substantiates the need to study the torrefaction of fuel from biomass in the atmosphere of its own gaseous medium formed during the thermal decomposition of organic substances. The methodology, equipment and devices for heat treatment of pine wood pellets are given. The results of a study using the TGA and DTA methods of the degree of thermal decomposition, equilibrium humidity, ash content and specific heat of thermal decomposition of torrefied at 250, 270 and 290 °С and the initial biofuel are presented. It is shown that an increase in the heat treatment temperature leads to an increase in the degree and temperature range of fuel decomposition, an increase in the specific heat of thermal decomposition, a decrease in hydrophilicity, and an increase in ash content. The degree of decomposition of torrefied biofuel with an increase in the treatment temperature within the indicated limits decreased from 7.81 to 4.89%, which indicates an insignificant balance of hemicellulose. Heat treatment caused an increase in hydrophobicity, which manifested itself in a 2.8-fold decrease in the equilibrium moisture content of biofuel torrefied at 290 °С. Due to the invariability of the mineral composition and the decrease in dry weight, the ash content in torrefied fuel is higher than in the original. The specific heat of thermal decomposition of biofuel torrefied at 290°С increased by 65.4% compared to the initial one. The study of the method of torrefaction of biofuels at atmospheric pressure in a gaseous environment formed in a confined space during the thermal decomposition of organic substances, showed its effectiveness and the possibility of using it for heat treatment of biomass without the use of inert gases.

TGA and DTA of Composite Fuel and its Components

“…It is accompanied by active gas formation and thermal generation. As noted in [4], treatment of peat with a NaOH solution leads not only to the formation of water-soluble salts of humic acids, but also to qualitative changes in the organic substances remaining in the solid residue. Therefore, the thermal decomposition of organic substances of MPR, in contrast to the organic substances of the original peat, occurs in a wider temperature range and takes place in three stages.…”

“…The use of peat residue as a fuel requires increasing its calorific value and reducing the danger of formation of new phases during combustion, which can be solved by production of composite fuel using components with a higher calorific value and low ash content [4].…”