First prize winner at Research Showcase in Asian Institute of Technology in School of Environment, Resources and Development

1. AIT RESEARCH SHOWCASE, May 2012
ENHANCEMENT OF DELIGNIFICATION BY AROMATIC SCAVENGERS
Yakindra Prasad Timilsena1*, Nicolas Brosse2 & Sudip Kumar Rakshit3
1Asian Institute of Technology, Pathumthani 12120,Thailand (*for correspondence: yakendra.timilsena@gmail.com)
2Université de Lorraine, Laboratoire d’Etude et de Recherche sur le MAteriau Bois, Faculté des Sciences et Technologies, Bld des
Aiguillettes, BP 70236, 54506 Vandoeuvre-lès-Nancy cedex, France
3Lakehead University, Thunder Bay, Ontario Canada P7B 5E1
Abstract Objective
Five different kinds of aromatic compounds • Compare the effect of different aromatics on
(naphthol, o-cresol, p-cresol, hydroquinone and delignification ability of miscanthus.
dihydroxy-anthraquinone) were assessed for their effect
on enhancement of organosolv delignification ability of Results and discussion
miscanthus. The biomass was treated with each of the
aromatic before autohydrolysis and the yield of ethanol • Ethanol organosolv lignin (EOL) yield was significantly
organosolv lignin (EOL) and the Klason lignin content of increased (13.3% in control whereas 23.4% in p-cresol
the pulp after 2-step pretreatment were compared with treatment).
the control and among the treatment. All the aromatics • Klason lignin content of the resultant pulp after 2-step
demonstrated a significant reduction in Klason lignin pretreatment was reduced significantly (14.9% in
content of the pulp and increased EOL recovery as control whereas 3.8% in p-cresol treatment).
compared to the control- naphthol, p-cresol and • ANOVA at 95% confidence level revealed significant
dihydroxyanthraquinone having the equivalent effect. difference in control and treatments, however, the effect
of p-cresol, naphthol and dihydroxyanthraquinone was
equivalent
Methodology • Path 2 in Fig. 2 shows the mechanism of scavenging the
carbonium ions which resulted in enhanced
delignification.
10 g ODW Miscanthus
Fig. 1. Effect of aromatics on delignification
Mixed with 0.4 g aromatics and soaked in 100 mL 30
acetone overnight EOL yield (% )
25 KL (%)
Yield (%)
Acetone evaporation by air drying 20
15
Autohydrolysis (1500C, 8h, S/L=1:9) 10
5
OS delignification (1700C, 1h, SA=0.5%, S/L=1:8) 13.3 14.9 20.8 5.9 16.8 7.3 23.4 3.8 17.8 8.3 22 4.8
0
Control Naphthol o-Cresol p-Cresol Hydroquinone DHAq
Treatments
Filtration Liquid EOL
phase
Fig. 2. Mechanism of carbonium ion scavenging
KL Pulp
Path 0
Conclusion and Future Work
• Aromatic compounds demonstrated significant
enhancement in delignification ability of miscanthus
during two step pretreatment process.
• Assessment of additional aromatics for their effect on
delignification of more lignocellulosic feedstocks is
suggested for future work.
SDCC / AIT – France Network The author is highly obliged to Prof. Sudip K. Rakshit and Prof. Nicolas Brosse for their invaluable advice
during this study. Financial support from SDCC/AIT-France Network is highly appreciated.