Effects of Forces, Particle Sizes, and Moisture Contents on Mechanical Behaviour of Densified Briquettes from Ground Sunflower Stalks and Hazelnut Husks

Abstract

Using the uniaxial compression process, the mechanical behaviour of densified briquettes from ground sunflower stalks and hazelnut husks was studied under different forces (100, 200, 300, and 400 kN), particle sizes (0, 3, 6, and 10 mm), and moisture contents (sunflower; 11.23%, 14.44%, and 16.89% w.b.) and (hazelnut; 12.64%, 14.83%, and 17.34% w.b.) at a constant speed of 5 mm min−1. For each test, the biomass material was compacted at a constant volume of 28.27 × 10−5 m3 using a 60 mm-diameter vessel. Determined parameters included densification energy (J), hardness (kN·mm−1), analytical densification energy (J), briquette volume (m3), bulk density of materials (kg·m−3), briquette bulk density (kg·m−3), and briquette volume energy (J·m−3). The ANOVA multivariate tests of significance results showed that for ground sunflower stalk briquettes, the force and particle size interactions had no significant effect (p > 0.05) on the above-mentioned parameters compared to the categorical factors, which had a significant effect (p < 0.05) similar to the effects of forces, moisture contents, and their interactions. For ground hazelnut husk briquettes, all the factors and their interactions had a significant effect on the determined parameters. These biomass materials could be attractive for the briquette market.

Keywords

• biomass densification
• mechanical compaction
• processing factors
• briquette durability
• multivariate tests of significance