Beschreibung:
<jats:title>Abstract</jats:title>
<jats:p>Production of briquette bio-fuel is related to several aspects of densification process. The present paper deals with the relation between briquette volume density ρ (kg·m<jats:sup>−3</jats:sup>) and required deformation energy E<jats:sub>d</jats:sub> (J). Wood, energy crop and cardboard feedstocks were compressed by a laboratory briquetting press of two diameters (40 and 65 mm); in this way six kinds of briquette samples (W<jats:sub>40</jats:sub>, W<jats:sub>65</jats:sub>, E<jats:sub>40</jats:sub>, E<jats:sub>65</jats:sub>, C<jats:sub>40</jats:sub>, C<jats:sub>65</jats:sub>) were produced. The values of compressing force F (N) and briquette volume density ρ were measured directly during feedstock densification; the deformation energy E<jats:sub>d</jats:sub> was calculated subsequently. The amount of deformation energy E<jats:sub>d</jats:sub> consumed within the achievement of specific briquette volume density ρ levels differed in case of all samples, the same as the maximum achieved briquette volume density ρ levels. Best results, i.e. efficiency of briquette production (the highest ρ, the lowest E<jats:sub>d</jats:sub>), were achieved by cardboard samples, followed by wood and finally by energy crop samples. An overall evaluation indicated a higher production efficiency of briquette samples 40 mm in diameter and the disadvantage of the production of briquette samples with briquette volume density ρ > 1000 kg·m<jats:sup>−3</jats:sup>; above such level, the amount of consumed deformation energy E<jats:sub>d</jats:sub> increased disproportionately sharply.</jats:p>