Effect of severity on dilute acid pretreatment of lignocellulosic biomass and the following hydrogen fermentation

Abstract

This study aimed to investigate the relationship of the severity of dilute acid pretreatment and the following dark hydrogen fermentation performance. Empty palm fruit bunch, rice husk, and pine tree wood were hydrolyzed in 5% (v/v) H2SO4 at 10% (w/v) solid/liquid ratio and 121 °C for 30, 60, and 90 min, and then used as the substrate of batch hydrogen fermentation. The maximum sugar yield was achieved at pretreatment with 60 min reaction time; however, it did not guarantee the maximum H2 production. Hydrolyzate obtained from pretreatment where the combined severity factor was at or over 2.01 showed severe 5-hydroxymethylfurfural production and consequent decrease of H2 production rate. Peak H2 production rates of 2640, 3340, and 2565 mL H2 L−1 day−1 were achieved at the following severity factors: 1.95, 1.86, and 1.83, for empty palm fruit bunch, rice husk, and pine tree wood, respectively.