Combined Effects of Solid-to-Liquid Ratio and Ethanol Concentration on the Organosolv Delignification of Extractives-Free Bagasse

Abstract:

The delignification of biomass serves as an important pre-treatment step for the subsequent valorization of the three key lignocellulosic components (i.e. cellulose, hemicellulose, and lignin). Among the delignification methods, much effort on research currently has been on organosolv processes, especially on ethanol organosolv, due to its advantages. This study investigated the effects of solid-to-liquid ratio and solvent concentration on the ethanol organosolv delignification from sugarcane bagasse. The extractives-free bagasse was delignified for 4 hours at 95°C (open reflux) with 1.50% v/v sulfuric acid as catalyst at varied process parameters: 50-80% ethanol concentration, and 1/20 – 1/30 S/L ratio. The experimental results show that for a low ethanol concentration, delignification is more effective when a low S/L ratio is used. Conversely, a high ethanol concentration can be effectively carried out at a higher S/L ratio. Moreover both parameters investigated have a significant (p<0.05) individual effect on delignification, but their combined effect is of greater influence. A maximum lignin fraction yield of 30.28% and a pulp yield of 73.54% was obtained at an S/L ratio of 1:30 and a solvent concentration of 50% ethanol. A time profile study conducted at the best condition chosen showed that time has a positive effect on delignification. Delignification continued as time progressed with a 49.94% lignin fraction yield achieved at pulping time of 8 hours. The ethanol delignification of extractives-free bagasse followed a first-order reaction.

• Periodical: Applied Mechanics and Materials (Volume 930)
• Pages: 13-30
• DOI: https://doi.org/10.4028/p-Oi1nHo
• Online since: February 2026
• Authors: Ian Dominic F. Tabañag*, Chloe Faye L. Go, Newson Shann L. Uy, Lorraine Claire C. Uy, Luis K. Cabatingan
• Keywords: Delignification Kinetics, Ethanol Organosolv Delignification, Extractives-Free Bagasse, Full Factorial Design

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