Influence of the Die Height on the Density of the Briquette Produced from Shredded Logging Residues

Abstract

An alternative to plant biomass of various origins are forest logging residues. They differ significantly from other, previously used plant materials. This difference is due to the heterogeneous composition and relatively large size of individual particles. This research on the compaction of this type of shredded material was aimed at determining the influence of the die height on the density and relaxation of briquettes. This parameter is crucial for the proper construction of compaction devices. The measurements were carried out for the same fractional composition of the shredded logging residues, with variable input parameters of the material and process. It was found that the briquette density and relaxation are influenced by the die height, as well as the material moisture content and process temperature. The highest density at maximum compaction pressure (1.40 g·cm–3) was obtained at a moisture content of 16%, temperature of 80 °C, and the lowest die height (195 mm). In the case of the briquette density after ejection from the die, the best results were obtained at the same temperature and die height but at a moisture content of 9%. The tests confirmed that, regardless of the process temperature and material moisture, the briquette density increases as the die height is reduced. The relaxation coefficient of compacted logging residues ranges from 21.7% to 50.1% and depends mainly on the material moisture content and the temperature of the process. The lowest value of the relaxation coefficient (21.7 ± 1.61) was obtained at 9% moisture content, 60 °C temperature, and 220 mm die height.

Some Properties of Briquettes and Pellets Obtained from the Biomass of Energetic Willow (Salix viminalis L.) in Comparison with Those from Oak (Quercus robur)

“…Lignocellulosic briquettes and pellets are solid fuel products whose main advantage is the densification of small lignocellulosic biomass up to a density of 800-1250 kg/m 3 [37][38][39]. They maintain the advantages of lignocellulosic biomass, including those related to renewability [40], environmental friendliness [41], and neutrality of carbon dioxide emission [42].…”

Evaluation of the Physical, Mechanical, and Calorific Properties of Briquettes with or without a Hollow Made of Wheat (Triticum aestivum L.) Straw Waste

“…Ash content is limited above 1.5% by SS 18 71 20/Sweden, CTI-R 04/5, and DIN 51731, and at 6% by ÖNORM M7135/Austria [20]. Many authors [10,[23][24][25][26][27][28][29] have analyzed the physical-mechanical and caloric properties of lignocellulose briquettes.…”