Fractionation of Eucalyptus grandis chips by dilute acid-catalysed steam explosion.

摘要: Abstract Steam explosion of Eucalyptus grandis has been carried out under various pretreatment conditions (200–210 °C, 2–5 min) after impregnation the wood chips with 0.087 and 0.175% (w/w) H 2 SO 4 . This study, arranged as a 3 factorial design, indicated that temperature is most critical variable affecting yield steam-treated fractions. Pretreatment -impregnated at 210 °C for min was best condition hemicellulose recovery (mostly xylose) in water soluble fraction, reaching almost 70% corresponding xylose theoretical yield. By contrast, lower temperatures 200 were enough to substrates from which 90% cellulose conversion obtained 48 h, using low enzyme loadings Celluclast 1.5 l plus Novozym 188 mixture (Novo Nordisk). Release water-soluble chromophores monitored by UV spectroscopy their concentration increased severity. The alkali-soluble lignin higher levels acid temperatures. Thermoanalysis these fractions pattern fragmentation towards greater severities but condensation prevailed drastic conditions.