Abstract:

There is a wide-spread interest in examining the alternative liquid fuels that are more sustainable and environmentally friendly than gasoline. In this paper,first,several alternative liquid fuels,such as biomethanol,bioethanol and biobutanol,are introduced,bioethanol being a leading one due to its potential. Then,the materials for bioethanol production are summarized,finding that lignocelluloses are paid more attentions to because the starch- or sugar-based productions are restricted by current policies. Moreover,the pretreatment methods for different kinds of lignocelluloses are analyzed,and the dilute acid pretreatment alone or that combined with steam explosion is found to be more efficient and economic than many other pretreatment
options. However,as dilute acid has a tendency to generate compounds inhibiting fermentation,such as furfural,hydroxymethyl furfural and small-molecular lignin,some countermeasures should be taken during the analysis and process design to limit the production and impact of these compounds.

Key words: biomass, lignocellulose, pretreatment, bioethanol