Effect of Dilute Acid and Alkaline Pretreatment of Typha australis (Typha Grass) for Bioethanol Production

Abstract

Typha australis (Typha grass) obtained from Kware Lake was used in this research to produce bioethanol. Different pretreatment methods including dilute acid (0.2M H2SO4), dilute alkaline (0.2M NaOH) and liquid hot water pretreatments were used to pretreat the Typha grass sample before enzymatic saccharification for 7 days using Aspergillus niger isolated from soil sediment and the hydrolysate was seeded with Saccharomyces cerevisiae isolated from palm wine to produce bioethanol. HPLC was used to analyze bioethanol product. The result showed that pretreatment with 0.2M H2SO4 removed more hemicelluloses (7.0%) when compared with other pretreatment methods used, but pretreatment with 0.2M NaOH and liquid hot water removed more lignin (14.29%) than dilute acid pretreatment. The highest percentage reducing sugar concentration of 0.58% was obtained from lower part of the sample pretreated with liquid hot water while Typha grass pretreated with 0.2M H2SO4 and 0.2M NaOH produced the highest percentage reducing sugar concentration of 0.32% each from the upper part of the sample. Also, the highest Bioethanol concentration of 2.07% was obtained at day 6 of fermentation from the Typha grass pretreated with liquid hot water while Typha grass pretreated with 0.2M H2SO4 and 0.2M NaOH produced highest Bioethanol concentration of 0.43% and 0.54% respectively. The results indicate that Typha grass can be harnessed for bioethanol production thereby reducing their negative impact on Lakes.