Ftir and Chemometric Study of Densified Solid Biofuel Produced Under Sub-Critical Water and its Characteristics Affected by Lignocellulose Substances

This research focuses on the chemical transformation of solid biofuel, Bio-coke, produced under the subcritical water stage. The authors aim to study the effect of additional lignocellulose (cellulose, hemicellulose, and lignin) substances on the structural reaction via ATR-FTIR and the Bio-coke characteristics for the industrial quality control purpose. Principal component regression (PCR) analyzes the structural alteration between mixtures, materials, and Bio-coke samples, then determine the correlation between these changes and the Bio-coke’s particle density, high heating value, and maximum compressive strength. Results show a significant relationship between changes in the 1800–1500 and 800–400 cm -1 regions of FTIR and the maximum compressive strength of the Bio-coke. The lignin cleavage caused the changes in the 1800–1500 cm-1 region. The greater the lignin concentration, the better a reaction was detected. Alteration in the 800–400 cm -1 region resulted from higher cellulose content in the Bio-coke, which decreased the Bio-coke’s maximum compressive strength. Hemicellulose content influenced the particle density of the product but did not show any correlation to the structural changes in this study setup.