Title
Comparative evaluation of chemical pretreatments for simultaneous removal of silica and lignin from rice straw
Authors
ANJALI SHARMA, KULDEEP YADAV, DALJEET KAUR, NITU MOR, SUNITA DALAL and JITENDER SHARMA

Received March 6, 2025
Published Volume 59 Issue 7-8 July-August
Keywords silica, lignin, cellulose, chemical treatment, rice straw

Abstract
This study investigates the efficacy of various chemical pretreatments for the concurrent removal of silica and lignin from rice straw. The impact of different alkali (NaOH, Ca(OH)2, and lime) and acid (H2SO4), at varied concentrations, on rice straw composition was assessed. Fourier transform infrared (FTIR) spectroscopy and field emission scanning electron microscopy (FE-SEM) were employed to analyze the morphological and chemical changes in treated and untreated rice straw. The results showed that H2SO4 pretreatment exhibited the most pronounced effect on rice straw morphology, with significant removal of lignin and silica. Chemical proximate analysis and characterization of lignin, hemicelluloses, cellulose, hollocellulose, ash and silica content of the dry matter of both untreated and treated rice straw were performed using the standard TAPPI Methods T257cm/85 (Technical Association of the Pulp and Paper Industry). Proximate analysis revealed that H2SO4 treatment achieved the highest reduction in silica and ash content. The findings of this study highlight the potential of chemical pretreatment for enhancing the suitability of rice straw as a feedstock for various applications.