Preparation of coconut husk
Young coconut husk was used in this study. After drying, they were cut into pieces
approximately 25 x 25 x 5 mm by a laboratory chipper. The experiment was performed according to
the Factorial in CRD with 2 factors; NaOH concentration (20, 25 and 30% based on raw material dry
weight) and boiling time (2 and 3 h) as shown in Table 1. All the treatments were performed at 100 C
with 2 replications. After that, the treated fiber was subjected to the 25% (based on fiber dry weight)
NaOH solution at 170 C for 3 h under pressure to obtain coconut husk pulp. Excess chemical was
removed by thorough washing with water and the pulp was oven-dried. This would be used as
substrate for further ethanol fermentation.