Monday, May 5, 2008
7-11

Simultaneous Saccharification and Fermentation of Pretreated Olive Pruning for Bioethanol Production

Paloma Manzanares1, M.Jose Negro1, J.Miguel Oliva1, Felicia Saez1, Ignacio Ballesteros1, Mercedes Ballesteros1, Cristóbal Cara2, Encarnación Ruiz2, and Eulogio Castro2. (1) Renewable Energies Department, CIEMAT, Avda. Complutense 22., Madrid, 28040, Spain, (2) Chemical, Environmental and Materials Engineering, University of Jaen, Campus Las Lagunillas, Jaen, 23071, Spain

 Olive tree pruning is a largely available renewable agricultural residue in the Mediterranean countries with no industrial applications. Apart from a limited application as domestic firewood, it is nowadays disposed in the field causing economic and environmental problems. As an alternative use, this residue could provide a promising feedstock for bioethanol industry, due to its carbohydrate content (about 50% on dry matter basis). However, research is needed to determine the feasibility to produce ethanol from this raw material by technologies developed so far.

 Among biomass to ethanol available technologies, enzyme-based conversion technologies present important advantages because they catalyze only specific reactions and consequently there are no side reactions or by-products and the hydrolysis can potentially be performed at very high yields. The pre-treatment step required to break the lignocellulose structure has been studied in depth and several process technologies, as those based in the use of hot water or dilute-acid, have been proved to be very effective to improve enzymatic digestibility of raw material.

 In the present study olive tree pruning biomass pretreated by both Liquid Hot Water (LHW) and diluted sulfuric acid was tested as substrate for ethanol production by the Simultaneous Saccharification and Fermentation (SSF) process. Three different process configurations, separate hydrolysis and fermentation (SHF), simultaneous saccharification and fermentation (SSF) and presaccharification and simultaneous saccharification (PSSF), regarding ethanol production from pretreated olive tree pruning were compared at different water insoluble solids concentration. Main results of this research will be reported.