A review of recent advancements in pretreatment techniques of lignocellulosic materials for biogas production: Opportunities and Limitations

Abstract

To overcome the energy demand and environmental issues by applying ecofriendly techniques to produce green energy are getting high attentions in these days. Lignocellulosic materials are the most abundant resource of biomass on earth and these materials have become vital for anaerobic digestion. However, the structure of lignocellulosic materials is difficult to degrade during anaerobic digestion. Physical, thermal, chemical and thermochemical techniques have been widely used for the pretreatment of lignocellulosic materials, which might facilitate the degradation of pretreated lignocellulosic materials during anaerobic digestion. Further, in recent years many updated and advanced techniques have also been developed for the pretreatment of lignocellulosic materials. Therefore, this study systematically summaries the novel techniques and chemicals used for physical, thermal, chemical and thermochemical pretreatments of lignocellulosic materials for the enhancement of anaerobic digestion. In addition, the mechanism, applications, advantages and disadvantages and challenges of each type of the pretreatment have also been identified. Finally, this study will provide new ideas for the development of new pretreatment techniques.

Keywords

• Pretreatments
• Lignocellulosic materials
• Anaerobic digestion
• Cellulose & hemicellulose
• Lignin