Optimization of the process conditions for preparing methylcellulose from sugarcane bagasse using response surface methodology (RSM)

Methylcellulose is a cellulose ether derivative obtained through the chemical modification of cellulose via the methylation process. Sugarcane bagasse, a rich source of lignocellulosic biomass, provides an abundant supply of cellulose suitable for methylcellulose production. The properties of methylcellulose are significantly influenced by three key methylation process variables: NaOH concentration, methylation temperature, and the type of solvent used. In this study, Response Surface Methodology (RSM) was employed to investigate and optimize these process conditions for the preparation of methylcellulose from alpha-cellulose extracted from sugarcane bagasse. A Central Composite Design (CCD) was prepared to analyze the effects of independent variables, including, NaOH concentration (30%, 40%, and 50%), methylation temperature (40 °C, 50 °C, and 60 °C), and solvent type (acetone, toluene, and 2-propanol) on the response variables, namely, degree of substitution (DS), methoxy content (%), and solubility (%). All three factors had a statistically significant influence on the responses. The regression models exhibited a coefficient of determination (R²) greater than 0.8, indicating a good fit for the experimental data. The optimal conditions identified through RSM were 40% NaOH concentration, a methylation temperature of 50 °C, and acetone as the solvent.