Abstract
A bench type twin gear reactor (TGR) was adapted as a two-step acid hydrolysis scheme for the high solids loading of biomass. In the first step, Box Behnken Design was used to optimize pretreatment conditions in terms of temperature of (60–100 °C), sulfuric acid concentration of (6–10%) and process time of (2.5–4 min) for the recovery of fermentable sugar monomers. After the first step, the subsequent hydrolysis was performed with either the TGR assisted chemically mediated way and/or with the incorporation of enzymes. A significant reduction in enzyme dosage was observed for sequentially acid hydrolyzed samples as compared with the typical enzyme hydrolysis one. SEM images also confirmed this effectiveness through the formation of surface pores. The pretreated and sequentially hydrolyzed samples were surely disrupted and showed a gradual variation in their surface features. These results conclusively suggest that two-step TGR based acid treatment can be an economical option for the hydrolysis of lignocelluloses.
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•Twin gear reactor was found to be an effective sequential acid hydrolysis scheme.•The enzyme dosage was noticeably reduced after sequential hydrolysis.•Sequentially hydrolyzed samples were significantly altered in the structural features.