Mechanical Pretreatment of Lignocellulosic Biomass Using a Screw Press as an Essential Step in the Biofuel Production

Abstract

Since mechanical pretreatment makes lignocellulosic biomass accessible to any further solution and (bio-)chemical modification processes, it is a step which is essential for the entire downstream processing. The objective of the work presented is to develop a mechanically based pretreatment process for biomass using a screw press. The screw press used for this purpose is an oil press which is known to provide continuous high shear and pressure forces. The results obtained in this study show the feasibility and potential for degradation of the lignocellulosic structure as well as dewatering of biomass in the screw press. Adsorption and extraction studies indicate that the products from the screw press have a larger specific surface area and more disruption of cell structure than those treated only with a cutting mill. Furthermore, it is found that the process with a screw press requires considerably less energy in comparison to the conventional thermal-mechanical process.