초록
<P><B>Abstract</B></P> <P>Olive stones are an agro-industrial by-product in Mediterranean countries that can be regarded as a potential source of bio-fuels and bioactive compounds. In this work, olive stones were pretreated with liquid hot water (LHW), dilute sulphuric acid (DSA) and organosolv delignification at temperatures in the range 190 °C–230 °C. The resulting solids from pretreatments were subjected to simultaneous saccharification and fermentation (SSF) with the yeast <I>Saccharomyces cerevisiae</I> IR2-9a for fuel-ethanol production. The composition of prehydrolysates from LHW and DSA pretreatments were strongly dependent of reactor temperature. The highest yields of <SMALL>D</SMALL>-xylose (0.21 kg kg<SUP>−1</SUP>) and <SMALL>D</SMALL>-glucose (0.11 kg kg<SUP>−1</SUP>) were achieved in DSA assays at 200 °C and 230 °C, respectively, while LHW processes provided the maximum oligosaccharide recovery (0.17 kg kg<SUP>−1</SUP>) at 210 °C. The addition of sulphuric acid in organosolv pretreatments was particularly effective to increase the cellulose content of the pretreated solids till percentages close to 83%. Finally, the maximum ethanol concentration achieved by SSF was 47.1 kg m<SUP>−3</SUP>, and 13 kg ethanol were obtained from 100 kg of raw material.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Ethanol-based organosolv treatment was assayed for first time on olive stones. </LI> <LI> High lignin and xylan removal from biomass was obtained. </LI> <LI> The effect of particle size on fuel-ethanol production was assessed. </LI> <LI> Complete conversion of pretreated cellulose to ethanol was achieved. </LI> </UL> </P>