E3S Web of Conferences (Jan 2021)

Possibilities for obtaining pellets by single-screw extrusion of biomass from black pine (Pinus nigra Arn.)

  • Simitchiev Apostol,
  • Bozadzhiev Bozidar,
  • Lazarov Lazar,
  • Stankov Stanko,
  • Fidan Hafize,
  • Stoyanova Albena

DOI
https://doi.org/10.1051/e3sconf/202132702010
Journal volume & issue
Vol. 327
p. 02010

Abstract

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The aim of the present study was to investigate the possibilities for obtaining pellets by single-screw extrusion of black pine (Pinus nigra Arn.) biomass. Two fractions of black pine needles – 1) with dp ≥ 500 μm and bulk density ρn = 0.243 g/cm3 and 2) black pine twigs with d ≥ 500 μm and ρn = 0.297 g/cm3, were obtained. Wheat bran with dp ≥ 500 μm and bulk density ρn = 0.258 g/cm3 in a ratio of 1:1 was added to the obtained fractions. The experiments showed that getting pellets by single-screw extrusion of biomass from twigs and needles of black pine was possible when mixing them in a 1:1 ratio with wheat bran. The addition of wheat bran improved the smoothness and homogeneity of the produced pellets and increased their density. High-density pellets with a low sectional expansion index were produced during extrusion. The productivity of extruding mixtures of black pine twigs with wheat bran was 30% higher than that made from a mix of black pine needles and wheat bran. The pellets obtained after mixing biomass from black pine and wheat bran had over 13% higher density than those produced entirely from wheat bran. The presence of black pine biomass increased the quality of the final product while at the same time having a positive effect on both productivity and specific energy consumption.