Deep eutectic solvent-based pretreatment incorporated with pulsed electric field to enhance cellulose accessibility for advanced biomaterials
Angky Wahyu Putranto (a,b), Gek Cheng Ngoh (a*), Adeline Seak May Chua (a), and Sri Suhartini (c)

a) Sustainable Process Engineering Centre, Department of Chemical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
*ngoh[at]um.edu.my

b) Department of Bioprocess Engineering, Faculty of Agricultural Technology, Universitas Brawijaya, Jalan Veteran, Malang, East Java, 65154, Indonesia

c) Department of Agro-industrial Technology, Faculty of Agricultural Technology, Universitas Brawijaya, Jalan Veteran, Malang, East Java, 65154, Indonesia

Abstract

The empty fruit bunches (EFB) are the main waste produced during the oil palm processing. The high cellulose content in EFB has been widely explored in biofuels and advanced biomaterials such as cellulose nanocrystalline (CNC). During biomaterials production, pretreatment process plays an essential role in disrupting the lignocellulosic recalcitrant. Pretreatment processes with green solvents namely deep eutectic solvents (DESs), have been employed recently by direct heating for a duration between 8-12 hour. Yet, the DES-based pretreatment incorporated with non-thermal such as pulsed electric field (PEF) is unclear. Therefore, the aim of this research is to enhance cellulose fractionation from EFB pretreated by DES incorporating with PEF and to evaluate the performance based on its characteristics. The DES used were acidic-based (Choline chloride-lactic acid) and ternary DES (choline chloride-oxalic acid-ethylene glycol). The electric field strength (6, 10 and 14 kV/cm) and time variation at 1, 2 and 3 min were used during PEF treatment. The result showed that the pretreatment combination of DES (acidic and ternary) and PEF (14 kV/cm and 3 min) achieved higher cellulose content (above 75%wt) and lowest lignin content (below 1 %wt) as compared with that of DES-direct heating. The research finding gives an insight into the efficient, rapid and sustainable biomaterials production from EFB through high cellulose content obtained from the DES-PEF pretreatment

Keywords: Deep eutectic solvent- Empty fruit bunch- Pretreatment- Pulsed electric field- Cellulose

Topic: Renewable energy and biorefinery