Effect of lignocellulosic composition on biomass grindability for carbon-free power generation role of hemicellulose variation via pretreatment

Abstract

Biomass is a pivotal carbon-neutral fuel that captures carbon during plant growth and releases it upon combustion, offsetting fossil fuel use. However, biomass combustion faces challenges owing to its high moisture content, low calorific value, and low grindability, compounded by its fibrous structure that requires significant energy for pulverization. Torrefaction is a technology employed to enhance the grindability of biomass and address its inherent limitations. In this study, we aimed to predict the degree of woody biomass grinding at varying lignocellulose contents and grinding degree via torrefaction. Three wood pellet samples were subjected to torrefaction at five different temperatures (473, 493, 513, 533, and 553 K). The grindability was assessed using a Thermally Treated Biomass Grindability Index analysis. Additionally, the lignocellulose content was analyzed using thermogravimetric analysis, and the relationship between grindability and lignocellulose content was explored. The results indicated that hemicellulose and cellulose contents decreased with higher torrefied temperatures, leading to increased grindability. Building on these findings, a simple regression prediction model was developed to estimate biomass grindability based solely on lignocellulosic composition and proximate analysis parameters. The model demonstrated high predictive accuracy with a coefficient of determination (R²) of 0.881, underscoring its robust predictive value. This study provides essential insights for improving the grindability of biomass, supporting the broader adoption of biomass as a sustainable carbon-free fuel for power generation.