Bioethanol production from water hyacinth with isolated thermophilic microbial consortium from Kenya

Abstract

Bioethanol production from water hyacinth pretreated thermochemically through boiling in water with or without sodium chlorite, followed by fermentation with a locally isolated thermophilic bacteria consortium in a partially consolidated bioprocessing was investigated. The time yielding the maximum total reducing sugars was 2 h using 155 mg/g and 113 mg/g of pretreated and untreated water hyacinth samples, respectively. The optimized factors were inoculum dose (8.1%, v/v), temperature (48.8 °C) and time (52.3 h) which resulted into 7.2 g/L of predicted bioethanol concentration. In the experimental run, 7.7 g/L of ethanol was produced, which is close to the predicted value.

Keywords

• Bioethanol
• Central composite design
• <i>Eichhornia crassipes</i>
• Optimization
• Partially consolidated bioprocessing