Optimization of Sugar Palm Starch Waste Delignification Process for Membran Production

Sugar palm starch waste (SPSW) was biomass that produce from processing of sugar palm starch. SPSW contain high cellulose, hemicellulose, and lignin. Using lignocellulose from SPSW needs a pretreatment method to obtain highpurity cellulose and create an environmentally friendly method. The investigation focuses on determining the optimal NaOH concentration, temperature, and duration for hydrothermal-alkali treatment to remove hemicellulose and lignin, achieving high-purity cellulose. There is no further research regarding optimal conditions related to NaOH concentration, temperature, and duration for hydrothermal-alkali treatment to remove hemicellulose and lignin, achieving high-purity cellulose. This study aims to define optimal conditions for lignin and hemicellulose removal to obtain cellulose with high purity. The delignification process is carried out by hydrothermal and hydrothermal alkali activation. The hydrothermal activation removes hemicellulose, whereas the hydrothermal alkali activation removes lignin. In this study, Response surface methodology (RSM) was used to determine optimum conditions. The results were then structural and morphological identification using XRD, FTIR, and SEM. The optimization results obtained parameter values of 2% NaOH, temperature 120 °C for 120 minutes. The desirability value was 0.774, with a response value of 2.9 ± 1.7% for hemicellulose, 92.35 ± 1.06% for cellulose, and 2.45 ± 0.1% for lignin. FTIR results showed that lignin was absent during the delignification process. Meanwhile, in XRD, during the delignification process, the crystallization index (CI) decreases, and the crystallization size (CS) increases. SEM analysis results show that the morphology of the delignified SPSW becomes smoother after pretreatment, which indicates a decrease in hemicellulose and lignin content and a high level of cellulose purity. Further research is needed on other parameters, such as cellulose yield, energy consumption, and environmental impact. This research should also consider other potential pretreatment factors, such as pressure and catalysts in the hydrothermal process.