Production of fuel ethanol from steam-explosion pretreated olive tree pruning

Abstract This work deals with the production of fuel ethanol from olive tree pruning. This raw material is a renewable, low cost, largely available, and lacking of economic alternatives agricultural residue. Olive tree pruning was submitted to steam explosion pre-treatment in the temperature range 190–240 °C, with or without previous impregnation by water or sulphuric acid solutions. The influence of both pre-treatment temperature and impregnation conditions on sugar and ethanol yields was investigated by enzymatic hydrolysis and simultaneous saccharification and fermentation on the pretreated solids. Results show that the maximum ethanol yield (7.2 g ethanol/100 g raw material) is obtained from water impregnated, steam pretreated residue at 240 °C. Nevertheless if all sugars solubilized during pre-treatment are taken into account, up to 15.9 g ethanol/100 g raw material may be obtained (pre-treatment conditions: 230 °C and impregnation with 1% w/w sulphuric acid concentration), assuming theoretical conversion of these sugars to ethanol.

[1]  L. Jiménez,et al.  Influence of process variables in the ethanol pulping of olive tree trimmings. , 2001, Bioresource technology.

[2]  Ignacio Ballesteros,et al.  Ethanol production from pretreated olive tree wood and sunflower stalks by an SSF process. , 2006, Applied biochemistry and biotechnology.

[3]  M. Díaz,et al.  Optimization of hydrogen peroxide in totally chlorine free bleaching of cellulose pulp from olive tree residues. , 2003, Bioresource technology.

[4]  Ye Sun,et al.  Hydrolysis of lignocellulosic materials for ethanol production: a review. , 2002, Bioresource technology.

[5]  M. Galbe,et al.  Two-step steam pretreatment of softwood by dilute H2SO4 impregnation for ethanol production , 2003 .

[6]  Yuanxin Wu,et al.  Pretreatment by microwave/alkali of rice straw and its enzymic hydrolysis , 2005 .

[7]  L. Jiménez,et al.  Kinetics of acid hydrolysis of olive felling residues , 1992 .

[8]  M. Newman,et al.  Effects of temperature and moisture on dilute-acid steam explosion pretreatment of corn stover and cellulase enzyme digestibility , 2003, Applied biochemistry and biotechnology.

[9]  G. Zacchi,et al.  Optimization of steam pretreatment of corn stover to enhance enzymatic digestibility , 2004, Applied biochemistry and biotechnology.

[10]  A. Stams,et al.  Utilisation of biomass for the supply of energy carriers , 1999, Applied Microbiology and Biotechnology.

[11]  L. Jimenez,et al.  EXPLOITATION OF AGRICULTURAL RESIDUES AS A POSSIBLE FUEL SOURCE , 1991 .

[12]  G. Zacchi,et al.  The generation of fermentation inhibitors during dilute acid hydrolysis of softwood , 1999 .

[13]  Ignacio Ballesteros,et al.  Enhanced enzymatic hydrolysis of olive tree wood by steam explosion and alkaline peroxide delignification , 2006 .

[14]  Mohammed Moniruzzaman,et al.  Effect of steam explosion on the physicochemical properties and enzymatic saccharification of rice straw , 1996 .

[15]  F. Alfani,et al.  Comparison of SHF and SSF processes for the bioconversion of steam-exploded wheat straw , 2000, Journal of Industrial Microbiology and Biotechnology.

[16]  Mats Galbe,et al.  Comparison of SO2 and H2SO4 impregnation of softwood prior to steam pretreatment on ethanol production , 1998 .

[17]  José Luis Gómez Ariza,et al.  Comparative study of paper sheets from olive tree wood pulp obtained by soda, sulphite or kraft pulping , 2000 .

[18]  J. Parajó,et al.  Production of oligosaccharides by autohydrolysis of brewery's spent grain. , 2004, Bioresource technology.

[19]  L. Mojović,et al.  Production of bioethanol from corn meal hydrolyzates , 2006 .

[20]  A. Shahbazi,et al.  Application of sequential aqueous steam treatments to the fractionation of softwood , 2005, Applied biochemistry and biotechnology.

[21]  John N. Saddler,et al.  Optimization of monosaccharide recovery by post-hydrolysis of the water-soluble hemicellulose component after steam explosion of softwood chips , 2000 .

[22]  T. W. Jeffries,et al.  Metabolic engineering for improved fermentation of pentoses by yeasts , 2004, Applied Microbiology and Biotechnology.

[23]  M. Ballesteros,et al.  Ethanol from lignocellulosic materials by a simultaneous saccharification and fermentation process (SFS) with Kluyveromyces marxianus CECT 10875 , 2004 .

[24]  Inmaculada Romero,et al.  Ethanolic fermentation of phosphoric acid hydrolysates from olive tree pruning , 2007 .

[25]  I. Cullis,et al.  Effect of initial moisture content and chip size on the bioconversion efficiency of softwood lignocellulosics , 2004, Biotechnology and bioengineering.

[26]  Ignacio Ballesteros,et al.  Ethanol production from steam-explosion pretreated wheat straw , 2006, Applied biochemistry and biotechnology.

[27]  Ignacio Ballesteros,et al.  Ethanol production from olive oil extraction residue pretreated with hot water. , 2002, Applied biochemistry and biotechnology.