Pressurized Liquid Hot Water Pretreatment And Enzymatic Hydrolysis of Switchgrass Aiming at the Enhancement of Fermentable Sugars

Author(s)

Kaniye Gunes

Mine Yaglikci

Melih Soner Celiktas

Published: January 2020

ABSTRACT

Pressurized Liquid Hot Water (PLHW) process is an essential and new method to remove lignin from biomass for biorefinery applications. In this study, a cascade method was investigated to obtain reducing sugars of switchgrass using optimization of PLHW and enzymatic hydrolysis. Optimization of pressurized liquid hot water and enzymatic hydrolyses were achieved by Box-Behnken design. First, pretreatments including PLHW were carried out step by step, with respect to the independent variables such as temperature (100, 140, 180 °C), pressure (100, 150, 200 bar) and time (20, 40, 60 min) at fixed flow rate (2 ml/min). The conditions which give the most optimized reducing sugar were 122.12 °C, 100 bar and 50.08 min and optimized fermentable sugar content was measured 107.49 g/l. Then, enzymatic hydrolysis was applied to solid phase with 4.8 pH citrate buffer at 50 °C during 24, 48 and 72 h with the help of Novozyme 188 and Celluclast enzymes. The reducing sugar amount obtained from switchgrass with enzymatic hydrolysis was measured 248.23 g/L, which means totally 355.72 g/L.

Citation: Biofuels

Volume: 13

Keywords: Switchgrass / Liquid hot water / Energy crops / Enzymatic hydrolysis

DOI: https://doi.org/10.32329/uad.674544