Eucalyptus Kraft Lignin as an Additive Strongly Enhances the Mechanical Resistance of Tree-Leaf Pellets

Abstract

Pelleted biomass has a low, uniform moisture content and can be handled and stored cheaply and safely. Pellets can be made of industrial waste, food waste, agricultural residues, energy crops, and virgin lumber. Despite their many desirable attributes, they cannot compete with fossil fuel sources because the process of densifying the biomass and the price of the raw materials make pellet production costly. Leaves collected from street sweeping are generally discarded in landfills, but they can potentially be valorized as a biofuel if they are pelleted. However, the lignin content in leaves is not high enough to ensure the physical stability of the pellets, so they break easily during storage and transportation. In this study, the use of eucalyptus kraft lignin as an additive in tree-leaf pellet production was studied. Results showed that when 2% lignin is added the abrasion resistance can be increased to an acceptable value. Pellets with added lignin fulfilled all requirements of European standards for certification except for ash content. However, as the raw material has no cost, this method can add value or contribute to financing continued sweeping and is an example of a circular economy scenario.

Lignin-Reinforced Paper with Excellent Stability and Thermal Properties for an Efficient Heat Spreader

“…Despite the enhanced performances of paper-based conductive materials that have been achieved, they were not able to be scaled up in industrial applications due to the expensive raw material and complicated operational process. Lignin, as the structural support of wood fiber, has strong rigidity and extraordinary resistance to harsh environments, which endows fiber with high mechanical and structural stability. − Thus, the presence of lignin in the CF matrix will overcome the abovementioned defects, enhancing the stability of CF/AgNW paper to harsh environments. Beyond that, benefiting from the loose three-dimensional structure of lignin-abundant cellulosic fiber (LCF) paper, the personal heat-dispersive property of LCF/AgNW composite paper will be greatly improved.…”

Evaluation of kraft lignin and residues of sawmill for producing briquettes

“…The densification process parameters, as temperature and pressure, and raw material properties directly influence in the properties and quality of the densified biomaterials (Clavijo et al, 2020). Richards (1990); Gilvari et al (2019) and Silva et al (2021) highlighted that parameters of abrasion and impact resistance, compressive strength, and density are important analyze quality characteristics of a densified biomaterial.…”

Special Issue “Production of Biofuels and Numerical Modelling of Chemical Combustion Systems”

“…Notwithstanding, pellets from biomass cannot compete with those from fossil fuel sources because the biomass densifying process and the raw materials price make pellet production economically unfeasible. To overcome these issues, Clavijo et al propose the use of eucalyptus kraft lignin as an additive for tree-leaf pellet production [8]. The resulting pellets fulfilled all requirements of European standards for certification except for ash content.…”