Sugar extracted from Napier grass by alkaline hydrolysis

Abstract

The aim of this project is to utilize Napier grass for energy purpose apart from using as animal feed. Napier grasses can be hydrolyzed to some reducing sugars and therefore, produce bio- ethanol by fermentation. In this project, Napier grass was hydrolyzed with two alkaline solutions which are potassium hydroxide and calcium hydroxide at the same concentration of 2% and 121 ^oC. The obtained reducing sugars were examined by phenol-sulfuric method and the standard glucose solution was used to produce a calibration curve.  The effect of particle size of dried Napier grass was investigated by sieving it through 60, 80, 100 mesh and the hydrolysis time was varied at 60, 90, 120, 150 minutes. The hydrolysis results of using these two alkaline solutions are similar where smaller particle size of dried napier grass of 100 mesh was used. The concentration of reducing sugar from hydrolysis with calcium hydroxide was g/L at 60 minutes and this was thought to be due to the effect of two groups of OH-. Moreover, the concentration of reducing sugar obtained from using sodium hydroxide was g/L but this took longer hydrolysis time at 120 minutes. However, higher concentration of reducing sugar from using calcium hydroxide might be obtained before 60 minutes but no sample was taken for the investigation in this study.