Jump to Main Content
Conversion of olive tree biomass into fermentable sugars by dilute acid pretreatment and enzymatic saccharification
- Cara, Cristóbal, Ruiz, Encarnación, Oliva, José Miguel, Sáez, Felicia, Castro, Eulogio
- Bioresource technology 2008 v.99 no.6 pp. 1869-1876
- biomass, cellulose, enzymatic hydrolysis, enzymes, glucose, olives, raw materials, saccharification, solubilization, sulfuric acid, temperature, trees
- The production of fermentable sugars from olive tree biomass was studied by dilute acid pretreatment and further saccharification of the pretreated solid residues. Pretreatment was performed at 0.2%, 0.6%, 1.0% and 1.4% (w/w) sulphuric acid concentrations while temperature was in the range 170-210°C. Attention is paid to sugar recovery both in the liquid fraction issued from pretreatment (prehydrolysate) and that in the water-insoluble solid (WIS). As a maximum, 83% of hemicellulosic sugars in the raw material were recovered in the prehydrolysate obtained at 170°C, 1% sulphuric acid concentration, but the enzyme accessibility of the corresponding pretreated solid was not very high. In turn, the maximum enzymatic hydrolysis yield (76.5%) was attained from a pretreated solid (at 210°C, 1.4% acid concentration) in which cellulose solubilization was detected; moreover, sugar recovery in the prehydrolysate was the poorest one among all the experiments performed. To take account of fermentable sugars generated by pretreatment and the glucose released by enzymatic hydrolysis, an overall sugar yield was calculated. The maximum value (36.3g sugar/100g raw material) was obtained when pretreating olive tree biomass at 180°C and 1% sulphuric acid concentration, representing 75% of all sugars in the raw material. Dilute acid pretreatment improves results compared to water pretreatment.