IMAM   24519
INSTITUTO DE MATERIALES DE MISIONES
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
Enzymatic hydrolysis of pine pretreated with ethanol and sodium hydroxide
Autor/es:
KRUYENISKI, J.; FELISSIA, F.; AREA, M.C.
Lugar:
Concepción
Reunión:
Congreso; 3er Congreso Iberoamericano sobre Biorrefinerías (CIAB), 4to Congreso Latinoamericano sobre Biorrefinerías, y 2do Simposio Internacional sobre Materiales Lignocelulósicos; 2015
Institución organizadora:
CIADEB-RIADICYP-PROVALOR-BIOREN- Centro de Biotecnología UdeC- Unidad de Desarrollo Tecnológico (UDT)- VTT Technical Research Centre of Finland Ltd.-
Resumen:
Pinesawdust, the most abundant and underutilized forest-industrial waste, can beused as raw material in a biorefinery. A possible product is bioethanol, obtainedfrom cellulose present in this waste. The process involves three stages:pretreatment, enzymatic hydrolysis and fermentation. One of the mostinfluencing factor in the hydrolysis is the chemical composition of thesubstrate, which is directly linked with the kind and conditions of the pretreatmentto which the material was subjected. The aim of this work was to study theenzymatic digestibility of pine sawdust submitted to alkaline - ethanolpretreatments. The experiments were conducted under two alkaline charges (15and 25% of sodium hydroxide on dried wood), two different times (60 and 90minutes), liquor/wood ratio of 5/1, maximum temperature of 170ºC, and analcohol/water ratio of 35/65. As reference, and to analyze synergic effects,the material was also treated separately with each reactive (soda and ethanol).The pretreated materials presented different chemical compositions, e.g.,lignin contents varied from 3 to 22% on dried wood. NREL (National RenewableEnergy Laboratory) standards were used for the characterization of the fibrousmaterial. NREL standards were used also as guide to make the enzymatic activityand the hydrolysis. The enzymatic hydrolysis was performed at 2% consistency,pH 4.8 and 50ºC, with an enzymatic charge of 20 FPU/ g glucans and 40 IU/ gglucans. The reaction was monitored every 24 hours until 72 hours. DNSmethodology was used to measure the percentage of reducing sugars after theenzymatic hydrolysis. The effect of alkaline charge on yields of reducingsugars was significant (p-value< 0.05), whereas the time did not show anyeffect. Ethanol and soda exhibited a positive synergy effect on the yield of reducingsugars. Results also suggest the existence of a negative correlation betweenthe yield of reducing sugars and lignin content of the pretreated material. Highestyield from the enzymatic hydrolysis was obtained with alkali-ethanolpretreatment using a high charge of soda, this material have a content oflignin lower than 7%.