Efficient removal of lignin with the maintenance of hemicellulose from kenaf by two-stage pretreatment process

• Main Authors: Wan Azelee, Nur Izyan, Md. Jahim, Jamaliah, Rabu, Amir, Abdul Murad, Abdul Munir, Abu Bakar, Farah Diba, Md. Illias, Rosli
• Format: Article
• Language: English
• Published: Elsevier B.V. 2014
• Subjects: TP Chemical technology
• Online Access: http://eprints.utm.my/id/eprint/52630/1/RosliMdIllias2014_Efficientremovalofligninwith.pdf; http://eprints.utm.my/id/eprint/52630/; http://dx.doi.org/10.1016/j.carbpol.2013.08.043

The enhancement of lignocellulose hydrolysis using enzyme complexes requires an efficient pretreatment process to obtain susceptible conditions for the enzyme attack. This study focuses on removing a major part of the lignin layer from kenaf (Hibiscus cannabinus) while simultaneously maintaining most of the hemicellulose. A two-stage pretreatment process is adopted using calcium hydroxide, Ca(OH)₂, and peracetic acid, PPA, to break the recalcitrant lignin layer from other structural polysaccharides. An experimental screening of several pretreatment chemicals, concentrations, temperatures and solid-liquid ratios enabled the production of an optimally designed pretreatment process for kenaf. Our results showed that the pretreatment process has provide 59.25% lignin removal while maintaining 87.72% and 96.17% hemicellulose and cellulose, respectively, using 1g of Ca(OH)₂/L and a 8:1 (mL:g) ratio of liquid-Ca(OH)₂ at 50 °C for 1.5 h followed by 20% peracetic acid pretreatment at 75 °C for 2 h. These results validate this mild approach for aiding future enzymatic hydrolysis.