Effects of particle size on biomass pretreatment and hydrolysis performances in bioethanol conversion

Abstract Many studies have investigated how particle size as a biomass physical feature influences sugar yield exclusively in enzymatic hydrolysis. However, without considering the effects of particle size on biomass preprocessing and pretreatment, it is difficult to select an optimal particle size...
Ausführliche Beschreibung

Abstract Many studies have investigated how particle size as a biomass physical feature influences sugar yield exclusively in enzymatic hydrolysis. However, without considering the effects of particle size on biomass preprocessing and pretreatment, it is difficult to select an optimal particle size range for bioethanol production considering the multistep nature of this process. Comprehensive effects of particle size on biomass preprocessing, pretreatment, and enzymatic hydrolysis were evaluated in this study by assessing biomass compositional and morphological features, characterizing biomass crystallinity and enzyme-accessible surface area, and studying hydrolysis sugar yield and its efficiency. Results indicated that submillimeter small particles (0.5, 0.25, and < 0.25 mm) experienced greater pretreatment severity and 5–10% more structural composition removal than their millimeter level counterparts (1–4 mm). Although small particles had about 10% higher enzymatic hydrolysis efficiency, the low pretreatment solid and sugar recoveries neutralized their enzymatic hydrolysis efficiency advantage over large particles. This trade-off suggested that there may exist little value in reducing particle size further under millimeter level, comparable total sugar yield can be achieved by biomass of millimeter particle sizes; in the meanwhile, employing millimeter particle sizes can conserve energy in biomass preprocessing since comminution is highly energy-intensive and costly. Ausführliche Beschreibung