Influence of Fraction Particle Size of Pure Straw and Blends of Straw with Calcium Carbonate or Cassava Starch on Pelletising Process and Pellet

Abstract

The aim of this study was to investigate the pressure agglomeration process of wheat straw (WS) and the blends of WS with calcium carbonate (CC) or cassava straw (CS) with a ratio of 6% wt./wt. from seven separate fractions with sizes in the range of 0.21–2.81 mm. The agglomeration was performed at a moisture of 30% wb and a material temperature of 78 °C, with a dose of 0.1 g, in a die of diameter 8 mm and height 80 mm. The effects of the process were evaluated based on the compaction parameters and the pellets’ density, tensile strength, and water absorption. The incorporation of additives into the WS improved the pellet process and quality. Refined results were achieved after adding CC, as compared to those achieved after adding CS, and the preferred particle size was in the range of 1.00–1.94 mm. This was because, under the given conditions, the back pressure in the die chamber significantly increased, allowing the achievement of a single pellet density of 800 kg·m−3. The pellets were resistant to compressive loads and cracked only at tensile strength of 6 MPa and a specific compression work of 6.5 mJ·mm−2. The addition of CC to the WS improved the strength of the adhesive and the cohesive bonds between the particles. The water absorption for the uncrushed pellets was considerably less than that for crushed pellets, which results in the safer storage of uncrushed pellets and excellent moisture absorption of crushed pellets. The addition of CC to the WS offers benefits in the form of pellet strength with a high water absorption capability. Notably, a study of crushed pellet litter under broiler rearing conditions and an analysis of the operational costs of using WS additives are required for implementing this study.

Cracking the Code: Process Parameter Effects on Khaya senegalensis Energy Pellet Moisture Content

“…In the same paper, it was stated that the presence of water within the raw material serves as a binding agent for biomass particles by facilitating starch gelatinization, protein denaturation, and partial solubilization of certain chemical components during the densification process. This results in the reinforcement and enhancement of bonds between biomass particles, ultimately leading to an improvement in the overall integrity of biomass pellets [9]. Nevertheless, the surplus water that particles are unable to assimilate adheres to the biomass surface, hindering particle consolidation and diminishing pellet excellence [10].…”

Wood pellets transport with vibrating conveyor: experimental for DEM simulations analysis

“…The method, quality, performance of transport and storage of bulk materials can be affected by parameters such as shape, symmetry, size of transported particles 14 and moisture 15 . Less examined properties that can also affect the transport of vibrational particles are friction parameters 16 , 17 . Evidently, when vibrations are applied, the behaviour of the particle changes.…”