Valorization of Waste Wood as a Solid Fuel by Torrefaction

Abstract

Abstract:The aim of this study was to investigate the optimal temperature range for waste wood and the effect torrefaction residence time had on torrefied biomass feedstock. Temperature range of 200-400 • C and residence time of 0-50 min were considered. In order to investigate the effect of temperature and residence time, torrefaction parameters, such as mass yield, energy yield, volatile matter, ash content and calorific value were calculated. The Van Krevelen diagram was also used for clarification, along with the CHO index based on molecular C, H, and O data. Torrefaction parameters, such as net/gross calorific value and CHO increased with an increase in torrefaction temperature, while a reduction in energy yield, mass yield, and volatile content were observed. Likewise, elevated ash content was observed with higher torrefaction temperature. From the Van Krevelen diagram, it was observed that at 300 • C the torrefied feedstock came in the range of lignite. With better gross calorific value and CHO index, less ash content and nominal mass loss, 300 • C was found to be the optimal torrefaction temperature for waste wood.

Relationship between Torrefaction Parameters and Physicochemical Properties of Torrefied Products Obtained from Selected Plant Biomass

“…The loss of mass during torrefaction results from the drying process and biomass of thermal degradation components, which Chen, Hill, and others have presented in their research [10,32]. According to Poudel and other authors [33], the loss of mass can reach the point where the torrefaction process is considered economically unprofitable. Therefore, the research carried out by many authors is aimed at providing an optimal range of temperatures that completely benefits the torrefaction process.…”

“…Changes in the properties of the biomass is shown in Figure 2. Biomass contains many significant cations important for plants and the environment, and is an excellent material that is a valuable source in fertilizing plants, as described by Werkelin et al [33]. The roasting process has an impact on improving its properties and obtaining bio preparations that can be used for fertilizing plants.…”

Fundamental Characteristics and Kinetic Analysis of Lignocellulosic Woody and Herbaceous Biomass Fuels

“…Through torrefaction, the surface of biomass with a pronounced distribution of hydrophilic functional groups turns hydrophobic, thus making it difficult for moisture adsorption to occur, which decreases the inherent moisture. The pretreatment process also assists with biomass pulverization via the destruction of its organic structure for higher effectiveness, and it mediates the devolatilization of a certain amount of volatile gases to increase the fixed carbon, thus resulting in increased calorific values [5][6][7]. Since torrefaction technology fundamentally depends on the pretreatment process under pyrolysis conditions for the production of carbon-rich fuels, it is essential that the basic pyrolysis characteristics of the biomass fuel are thoroughly understood through in-depth analyses of the biomass pyrolysis [8][9][10][11].…”

Torrefaction of Agricultural Residues: Effect of Temperature and Residence Time on the Process Products Properties

“…The term refers to thermal pretreatment in an inert atmosphere, usually at 200-300°C. The process mainly produces fuel (biochar) with high energy density and improved grindability [4][5][6] as a way to mitigate the drawbacks connected with transporting, handling, and milling raw biomass. Torrefied biomass is often referred to as "biocoal" because its grindable and combustible characteristics are close to those of coal, and it is expected to replace coal in existing heat and power generation plants [7].…”