enzymatic hydrolysis of olive industry solid waste into glucose, the precursor of bioethanol

Olive industry solid waste (oisw) is a byproduct generated in the process of olive oil extraction. it is a lignocellulosic material consisting of cellulose, hemicelluloses, lignin and other extractives. in this work, a process for hydrolyzing the oisw into its monomers glucose, the precursor of bioethanol was developed. the hydrolysis process involves two stages: in the first stage, the oisw was activated by treating it with a material that opened the cellulose structure and made it more accessible for chemical reagents. several activating materials were evaluated among them are water, naoh, ca(oh)₂ and acetic acid.  in the second stage, the oisw was subjected to an enzymatic treatment which hydrolyzed it into sugar. a combination of the two enzymes cellulase (endo-1,4-β-glucanase) and β-glucosidase was used in the hydrolysis. best hydrolysis results were obtained at enzymes dose of 15.0 mg of cellulase and 20.0 mg/g of β-glucosidase per one gram of oisw at 45 °c and a ph of 4.8. a yield of 85.02% sugar was obtained from the hydrolysis of 10% naoh pretreated oisw under a positive pressure of air.  whereas, hydrolysis of cellulose extracted from oisw by the kraft pulping process and bleached using dehp beaching sequence produced about 95.30% sugar.