Successful production of bioethanol from olive waste residues followed by its purification using poly (acrylonitrile-co-methylacrylate)/polymethylmethaacrylate membrane

Olive residues waste is one of the most abundant wastes that is produced in many olive-cultivating countries especially Saudi Arabia. The current research is interested in the proper exploitation of this waste as a source of alternative energy such as bioethanol. The waste was submitted for physical/chemical and enzymatic hydrolysis to increase the amount of the produced glucose that would be microbially fermented into bioethanol. The obtained data revealed that the highest glucose units were produced through the hydrolysis of olive waste by 10% H2SO4 and autoclaving followed by enzymatic hydrolysis by cellulase enzyme (700 U/g). These sugars were fermented by Saccharomyces cerevisiae under anaerobic conditions into bioethanol with the concentration of 1.05 mg/ml. The produced ethanol was subsequently purified using poly (acrylonitrile-co-methylacrylate)/polymethylmethaacrylate [P(AN-co-MA)/PMMA] membrane modified with ethylenediamine (EDA), which represented the beginning of a new challenge in ethanol separation and purification from water. The characterization of the membrane was performed through the investigation of the functional groups and the morphology via Raman spectroscopy, Fourier transform infrared (FTIR), and scanning electron microscope (SEM). Recovery of ethanol from mixture (ethanol/water) of the prepared ethanol and another bioethanol produced as a product from the fermentation process was performed using the amicon cell filtration system with the prepared membrane which successfully increased the flux of ethanol for both the bioethanol and the prepared one.