A comparative study on enzymatic hydrolysis of kenaf from two different harvest time-points, with- and without pretreatment

Kenaf biomass is potentially a valuable feedstock for bio-energy production due to fast growth of this plant, and its high capacity for carbon fixation and accumulation of carbohydrates. In this study, biomass productivity, chemical composition and physical properties of kenaf were investigated at two different harvest times. The average dry weight of early harvested biomass (EH, 109.0 g/plant) was lower than that of late harvested biomass (LH, 132.3 g/plant). However, the daily growth rates for EH and LH were 1.45 and 1.28 g/d, respectively. There was no significant difference in carbohydrate content between EH- and LH-kenaf, while lignin content increased with higher S/G ratio in LH-kenaf. The enzymatic conversion rates of EH- and LH-kenaf with/without popping pretreatment were 90.4%/41.2% and 65.0%/27.5%, respectively. We suggest that early harvest has a positive impact on kenaf biomass, which had a lower lignin content and cellulose crystallinity.