A new approach to develop cost-effective lignocellulosic bioethanol production

2\(^n\)\(^d\)-generation bioethanol can be produced from cellulose fraction present in lignocellulosic biomass and has become a significant research focus due to its potential for replacing fossil fuels and decreasing greenhouse gases emissions. In order to produce 2\(^n\)\(^d\)-generation bioethanol, biomass processing is required in order to access cellulose within lignocellulose and convert it into glucose. However, an efficient cost-effective and environmental-friendly process has not been achieved. The aim of this work was to produce glucose from purified cellulose from \(Miscanthus\) \(x\) \(giganteus\), an energy crop. The lignocellulosic biomass was selectively fractionated into its main components, hemicellulose, lignin and cellulose, after extractions using ‘green’ processes in a biorefinery approach. Hydrolysis of the cellulose-enriched fibres into glucose was evaluated using subcritical water (SBW) in a batch reactor at temperatures from 190-320oC, residence times from 0-54min and biomass loading from 0.5-6.4% (w/v). The process used for cellulose purification had significant effect on glucose production by SBW, and higher glucose yields were achieved at higher temperatures and shorter residence times. Glucose was used for bioethanol production. Although the formation of inhibitors during SBW hydrolysis could not be prevented, fermentation could be performed in the presence of these compounds at some conditions, with high ethanol yields.