Comparison of the Deep Euteutic Solvent (DES) Solvent for Extracting Lignin from the Lignocellulosic Material of Pineapple Leaves

Abstract

Background: Lignocellulosic biomass is one of the materials that has the potential to produce cellulose. Lignocellulose material consists of lignin, hemicellulose and cellulose so that the three materials must be separated first to get pure cellulose. The main problem faced in the process of separating cellulose is the difficulty of separating lignin. One of the processes in separating lignin is by pretreatment of lignocellulosic material. Methods: In this study, Deep Euteutic Solvent (DES) choline (ChCl) as a hydrogen bond acceptor was synthesized and eight hydrogen bond donors (HBD) were mixed. Eight types of DESs, i.e. , choline chloride-acetic acid (ChCl-AA), ChCl: formic acid (ChCl-FA). ), choline chloride: Lactic acid (ChCl-LA), choline chloride:Citric acid (ChCl-SA), choline chloride: Glycerol (ChCl-G), choline chloride: Ethylenglycol (ChCl-EG), choline chloride: Sorbitol (ChCl-S), and choline chloride: Urea (ChCl -U) with a ratio of 1: 2 were investigated. Each. DES solvent was applied as a pretreatment for the lignocellulosic material of pineapple leaves. The results of the pretreatment formed were characterized by the Infra Red spectroscopic method to determine the typical functional groups. Result: The results showed that the pretreatment process using DES solvent resulted in a decrease in lignin levels in pineapple leaf powder, the highest in DES with linear saturated acid-based HBD, formic acid at 32.05%, glycerol at 30.18% and then in alpha hydroxy-based HBD, acetic acid at 29.90%. Meanwhile, the FT-IR results show that ChCl-FA has a high delignification ability during pretreatment. Pineapple leaves that have been pretreted with DES solvent can be a potential raw material for the next conversion process. This study presents DES as an effective and easy pretreatment method for lignin extraction.

One-pot extraction of nanocellulose from raw durian husk fiber using carboxylic acid-based deep eutectic solvent with in situ ultrasound assistance

“…Finally, the residue was washed with excess water and dried at 105 ℃ until a constant weight was achieved. These remaining residues are quantified as alpha-cellulose, and the difference between the holocellulose and cellulose values provides the hemicellulose content of the samples [29] , [30] .…”

Morphological, characterization and FTIR analysis of delignified pineapple leaves as raw material for cellulose production

“…The pineapple leaves sample used was obtained from the city of Subang, Indonesia. The sample were washed, dried and refined as was the method used in previous studies [10]. The chemicals used in this study were choline chloride (Sigma Aldrich, 98% purity), formic acid (Merck, Purity).…”

“…In previous studies, pretreatment of lignocellulosic materials was carried out using DES solvents on biomasses such as rice straw, corn cobs, and lettuce [6][8] [9]. In a previous study, a comparison of DES solvent was carried out to remove lignin from pineapple leaf fiber and choline chloride : formic acid (1:2) combination gives results in a decrease in lignin content in pineapple leaves [10]. In this study, the analysis was carried out to study the morphology of the treated surface.…”

Mechanical pretreatment of lignocellulosic biomass toward enzymatic/fermentative valorization

“…These compounds are located in the plant cell wall; however, they are interlinked, forming a crystalline-like structure that makes it recalcitrant and hinders sugar release ( Soltaninejad et al., 2022 ). Therefore, LCB needs, in most cases, to undergo pretreatments to increase the accessibility of cellulose and, thus, increase the yield of the final processes ( Sumiati et al., 2021 ).…”