Staged organosolv pretreatment to increase net energy and reactive lignin yield in whole oil palm tree biorefinery

Md Khairul Islam; Amornpan Thaemngoen; Chun Yin Lau; Jianyu Guan; Chi Shun Yeung; Sumate Chaiprapat; Shao-Yuan Leu

doi:10.1016/j.biortech.2021.124766

Staged organosolv pretreatment to increase net energy and reactive lignin yield in whole oil palm tree biorefinery

Bioresour Technol. 2021 Apr:326:124766. doi: 10.1016/j.biortech.2021.124766. Epub 2021 Jan 25.

Authors

Md Khairul Islam¹, Amornpan Thaemngoen², Chun Yin Lau³, Jianyu Guan³, Chi Shun Yeung³, Sumate Chaiprapat², Shao-Yuan Leu⁴

Affiliations

¹ Department of Civil & Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; Research Institute for Sustainable Urban Development (RISUD), The Hong Kong Polytechnic University, Hung Hom, Hong Kong; Department of Applied Chemistry & Chemical Engineering, Rajshahi University, Bangladesh.
² Department of Civil Engineering, Faculty of Engineering, Prince of Songkla University, Hat Yai, Songkhla, Thailand.
³ Department of Civil & Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong.
⁴ Department of Civil & Environmental Engineering, The Hong Kong Polytechnic University, Hung Hom, Hong Kong; Research Institute for Sustainable Urban Development (RISUD), The Hong Kong Polytechnic University, Hung Hom, Hong Kong; Research Institute for Smart Energy (RISE), The Hong Kong Polytechnic University, Hong Kong. Electronic address: syleu@polyu.edu.hk.

PMID: 33529983
DOI: 10.1016/j.biortech.2021.124766

Abstract

Pretreatment is the most crucial and energy-intensive unit process affecting the feasibility of biorefinery, especially when lignin valorization is of concern. This study investigated and quantified the potential benefits of an innovative staged organosolv (OS)-dilute acid (DA) pretreatment process for whole oil palm tree residues conversion. The staged OS-DA pretreatment resulted in approximately five times higher net energy (1.50 GJ/tonne) over the single-step OSDA process (0.30GJ/tonne) due to potential energy saving on solvent recovery and less water consumption. For sugar, OS-DA pretreated substrate achieved more than 90% of cellulose digestibility which was more than 40% higher than DA-OS substrate. For mono-lignin, significant reduction in crude lignin condensation (21.7%) was confirmed by two-dimensional NMR analysis. The overall mass balance showed that approximately 142.45 tonnes of bioethanol, or a net energy yield of 969.5 GJ, can be produced by OS-DA process from palm tree residues per hectare of oil palm farm.

Keywords: Biofuel; Energy footprint; Lignin condensation; Organosolv pretreatment; Palm biomass.

MeSH terms

Biomass
Cellulose
Hydrolysis
Lignin*
Trees*

Substances

Cellulose
Lignin