DES Molar Ratio and Time-Driven Delignification of Pineapple Peel: Achieving Exceptional Lignin Removal and Cellulose Enrichment

Asyeni Miftahul Jannah, Gitareja Kania Azahra, Muhammad Yerizam

Abstract

This study examined the influence of Deep Eutectic Solvent (DESs) molar ratio and reaction time on the delignification of pineapple peel as a lignocellulosic biomass. Lactic acid was employed as the hydrogen bond donor (HBD), while choline chloride, betaine hydrochloride, and glycine were used as hydrogen bond acceptors (HBAs). The DESs molar ratios investigated were 1:4, 1:6, 1:8, and 1:10. Delignification was conducted at 121°C for 1, 2, and 3 h. The lignin, hemicellulose, and cellulose contents before and after delignification were determined using the Chesson–Datta method. Structural and morphological modifications of the biomass were evaluated by FTIR, SEM, and XRD analyses. The highest lignin removal was achieved using betaine:lactic acid DES with a molar ratio of 1:6 for 1 h. Under this condition, lignin removal reached 96.87%, with hemicellulose and cellulose contents of 7% and 79%, respectively. These results indicated that betaine:lactic acid DES effectively disrupts lignin bonds in pineapple peel compared to other DESs without damaging cellulose.

Keywords

References

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DOI: 10.14416/j.asep.2026.06.004

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