Appropriate Technology for the Bioconversion of Water Hyacinth (Eichhornia crassipes) to Liquid Ethanol

Abstract

This article appraises the need for introducing appropriate technology to improve the production of renewable energy, particularly on the community basis and social aspect of sustainability. Using two-sequential steps of acid hydrolysis (10% sulfuric acid) and yeast (Candida shehatae; xylose-fermenting yeast) fermentation, bioconversion of water hyacinth (Eichhornia crassipes; a noxious weed and fast growing aquatic plant widely distributed in many tropical regions of the world) to liquid ethanol has successfully been performed. The maximum ethanol yield coefficient of 0.19 g g-1 WH with the productivity of 0.008 g l-1 h-1 was achieved. This is as well comparable to those obtained from the enzymatic saccharification and/or the fermentation of acid-pretreated water hyacinth hydrolysate using fully-equipped fermenter reported elsewhere. More importantly, determinations of xylose and ethanol contents can potentially be performed using two reliable colorimetric approaches (Phloroglucinol and Dichromate assays, respectively) in conjunction with home-made portable photometer. The technology presented herein can be transferred and implemented to gain opportunity of becoming self-reliance of community in the third world countries.