Ethanol Production from Olive Stones through Liquid Hot Water Pre-Treatment, Enzymatic Hydrolysis and Fermentation. Influence of Enzyme Loading, and Pre-Treatment Temperature and Time

Olive table industry, olive mills and pomace oil extraction industries annually generate huge amounts of stones. One their potential applications is the production bioethanol by fractionation lignocellulose constituents subsequent fermentation released sugars using yeasts. In this work, we studied influence temperature (175–225 °C) residence time (0–5 min) in liquid hot-water pre-treatment stones as well initial enzyme loading (different mixtures cellulases, hemicellulases β–glucosidases) later enzymatic hydrolysis on release fermentable sugars. The Chrastil’s model was applied to d-glucose data relate severity diffusion through pre-treated cellulose. Finally, hydrolysate obtained under most suitable conditions (225 °C 0 min for pre-treatment; 24 CE concentration) fermented into ethanol yeast Pachysolen tannophilus ATCC 32691. Considering overall process, 6.4 dm3 per 100 kg were produced.