Utilization of microwave and ultrasound pretreatments in the production of bioethanol from corn

Bioethanol production by simultaneous saccharification and fermentation (SSF) of corn meal by Saccharomycescerevisiae var. ellipsoideus yeast in a batch system with prior ultrasound or microwave treatment was studied. The optimal duration of the pretreatments and the SSF process kinetics were assessed and determined. Also, the effect of ultrasound and microwave pretreatments on ethanol yield and productivity was investigated. An optimal duration of 5 min was determined for both pretreatments. Ultrasonic and microwave pretreatments effectively increased the glucose concentration obtained after liquefaction by 6.82 and 8.48%, respectively, compared to untreated control sample. Also, both pretreatments improved ethanol yield and productivity during the SSF process. Ultrasound and microwave pretreatments increased the maximum ethanol concentration produced in the SSF process by 11.15 and 13.40% (compared to the control sample), respectively. The application of microwave pretreatment resulted in higher glucose release during liquefaction and consequently in higher ethanol concentration, compared to ultrasound pretreatment. A maximum ethanol concentration of 9.91% (w/w) and percentage of theoretical ethanol yield of 92.27% were achieved after 44 h of the SSF process of corn meal with prior microwave treatment.

[1]  L. Jun,et al.  Salt-assisted acid hydrolysis of starch to D-glucose under microwave irradiation. , 2001, Carbohydrate research.

[2]  A. Pandit,et al.  Enzymatic production of glucose from different qualities of grain sorghum and application of ultrasound to enhance the yield. , 2009, Carbohydrate research.

[3]  Anton Friedl,et al.  Modeling and simulation of coupled ethanol and biogas production , 2010 .

[4]  M. Balat,et al.  Progress in bioethanol processing , 2008 .

[5]  S. Khanal,et al.  Ultrasound enhanced glucose release from corn in ethanol plants , 2007, Biotechnology and bioengineering.

[6]  G. Yadav,et al.  Microwave assisted enzyme catalysis for synthesis of n-butyl dipheyl methyl mercapto acetate in non-aqueous media , 2007 .

[7]  B. Chung,et al.  Simultaneous saccharification and fermentation of sludge-containing cassava mash for batch and repeated batch production of bioethanol by Saccharomyces cerevisiae CHFY0321 , 2009 .

[8]  Samir Kumar Khanal,et al.  Ultrasound improved ethanol fermentation from cassava chips in cassava-based ethanol plants. , 2010, Bioresource technology.

[9]  W. Horwitz,et al.  Official methods of analysis of AOAC International , 2010 .

[10]  Seungdo Kim,et al.  Environmental aspects of ethanol derived from no-tilled corn grain: nonrenewable energy consumption and greenhouse gas emissions , 2005 .

[11]  Belkıs Çaylak,et al.  Comparison of Different Production Processes for Bioethanol , 1998 .

[12]  M. Ballesteros,et al.  Pretreatment technologies for an efficient bioethanol production process based on enzymatic hydrolysis: A review. , 2010, Bioresource technology.

[13]  G. L. Miller.  Use of Dinitrosalicylic Acid Reagent for Determination of Reducing Sugar , 1959 .

[14]  D. Pejin,et al.  Bioethanol production from corn meal by simultaneous enzymatic saccharification and fermentation with immobilized cells of Saccharomyces cerevisiae var. ellipsoideus , 2009 .

[15]  Yuqing Zhang,et al.  Effect of Ultrasonic Waves on the Saccharification Processes of Lignocellulose , 2008 .

[16]  G A Hill,et al.  Effects of high product and substrate inhibitions on the kinetics and biomass and product yields during ethanol batch fermentation , 1992, Biotechnology and bioengineering.

[17]  Zhiyou Wen,et al.  Enhancing enzymatic digestibility of switchgrass by microwave-assisted alkali pretreatment , 2008 .

[18]  D. Pejin,et al.  Ethanol is a strategic raw material. , 2002 .

[19]  John N. Saddler,et al.  A comparison between simultaneous saccharification and fermentation and separate hydrolysis and fermentation using steam-pretreated corn stover , 2007 .

[20]  J. Mielenz,et al.  Ethanol production from biomass: technology and commercialization status. , 2001, Current opinion in microbiology.

[21]  Albert Mas,et al.  Effects of fermentation temperature on the strain population of Saccharomyces cerevisiae. , 2003, International journal of food microbiology.

[22]  Xiong Fu,et al.  Ultrasound Effects on the Structure and Chemical Reactivity of Cornstarch Granules , 2007 .

[23]  K. Seetharaman,et al.  Impact of microwave heating on the physico-chemical properties of a starch-water model system , 2007 .

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

[25]  S. Khanal,et al.  Ultrasound pretreatment of cassava chip slurry to enhance sugar release for subsequent ethanol production , 2008, Biotechnology and bioengineering.

[26]  Ziniu Yu,et al.  Simultaneous saccharification and fermentation of microwave/alkali pre-treated rice straw to ethanol , 2005 .

[27]  Wilerson Sturm,et al.  Production of bio-ethanol from soybean molasses by Saccharomyces cerevisiae at laboratory, pilot and industrial scales. , 2008, Bioresource technology.

[28]  Alex Patist,et al.  Ultrasonic innovations in the food industry: From the laboratory to commercial production , 2008 .