Subcritical water and dilute acid pretreatments for bioethanol production from Melaleuca leucadendron shedding bark

详细信息    查看全文

• 作者：Ibrahim Nasser Ahmed ; Sylviana Sutanto ; Lien Huong Huynh ; Suryadi Ismadji ; Yi-Hsu Ju
• 关键词：Glucose ; Cellulase ; Fermentation ; Ethanol ; Subcritical water ; Melaleuca leucadendron
• 刊名：Biochemical Engineering Journal
• 出版年：2013
• 出版时间：15 September, 2013
• 年：2013
• 卷：78
• 期：Complete
• 页码：44-52
• 全文大小：788 K

文摘

The feasibility of bioethanol production using the lignocellulose of the shedding bark of Melaleuca leucadendron (Paper bark tree) was investigated. The effects of pretreatment parameters (temperature, time and acid concentration) on the yields of sugars and inhibitors, and optimal pretreatment conditions were determined. At very low severity conditions (combined severity factor, CSF ¡Ü 0.335), 28 % of xylan was recovered and this recovery increased with increasing CSF till it peaked to 64.4 % (11.2 g xylose L^?1) at a CSF of 1.475. However, at CSF > 2.0, xylose yield declined due to degradation. Mild and progressive glucose yield was detected in prehydrolysate at CSF ¡Ý 1.514, and subsequent enzymatic hydrolysis allowed complete glucan solubilization. Implementing environmentally friendly subcritical water pretreatment at CSF ¡Ü 0.335 on the shedding bark, about 85 % of glucan solubilization was achieved after enzymatic hydrolysis. An industrial Saccharomyces cerevisiae strain readily fermented crude hydrolysate within 12 h, yielding 24.7 g L^?1 ethanol at an inoculum size of 2 % (v/v), representing a glucose to ethanol conversion rate of 0.475 g g^?1 (91 % ethanol yield). Based on our findings, the shedding bark is a potential feedstock for bio-ethanol production.