Characterization of Corn Cobs from Microwave and Potassium Hydroxide Pretreatment

Authors: Boonyisa Wanitwattanarumlug, Apanee Luengnaruemitchai, Sujitra Wongkasemjit

Abstract:

The complexity of lignocellulosic biomass requires a pretreatment step to improve the yield of fermentable sugars. The efficient pretreatment of corn cobs using microwave and potassium hydroxide and enzymatic hydrolysis was investigated. The objective of this work was to characterize the optimal condition of pretreatment of corn cobs using microwave and potassium hydroxide enhance enzymatic hydrolysis. Corn cobs were submerged in different potassium hydroxide concentration at varies temperature and resident time. The pretreated corn cobs were hydrolyzed to produce the reducing sugar for analysis. The morphology and microstructure of samples were investigated by Thermal gravimetric analysis (TGA, scanning electron microscope (SEM), X-ray diffraction (XRD). The results showed that lignin and hemicellulose were removed by microwave/potassium hydroxide pretreatment. The crystallinity of the pretreated corn cobs was higher than the untreated. This method was compared with autoclave and conventional heating method. The results indicated that microwave-alkali treatment was an efficient way to improve the enzymatic hydrolysis rate by increasing its accessibility hydrolysis enzymes.

Keywords: Corn cobs, Enzymatic hydrolysis, Microwave, Potassium hydroxide, Pretreatment.

Digital Object Identifier (DOI): doi.org/10.5281/zenodo.1062754

References:

[1] Carrillo F, Lis MJ, Colom X, Lo'pez-Mesas M, Valldeperas J. Effect of alkali pretreatment on cellulase hydrolysis of wheat straw: Kinetic study. Process Biochemistry 2005;40;3360-3364.
[2] Cheng J, Su H, Zhou J, Song W, Cen K. Microwave-assisted alkali pretreatment of rice straw to promote enzymatic hydrolysis and hydrogen production in dark- and photo-fermentation. International Journal of Hydrogen Energy 2011;36;2093-2101.
[3] Zhu S, Wu Y, Yu Z, Liao J, Zhang Y. Pretreatment by microwave/alkali of rice straw and its enzymic hydrolysis. Process Biochemistry 2005; 40;3082-3086.
[4] Abdullah SS, Yusup S, Ahmad MM, Ramli A, Ismail L. Thermogravimetry Study on Pyrolysis of Various Lignocellulosic Biomass for Potential Hydrogen Production. International Journal of Chemical and Biological Engineering 2010;72;129-133.
[5] Cao Y, Tan H. Study on crystal structures of enzyme-hydrolyzed cellulosic materials by X-ray diffraction. Enzyme and Microbial Technology 2005;36;314-317.
[6] Wang Z, Keshwani DR, Redding AP, Cheng JJ. Sodium hydroxide pretreatment and enzymatic hydrolysis of coastal Bermuda grass. Bioresource Technology 2010;101;3583-3585.
[7] Harmsen PFH, Huijgen WJJ, Berm├║dez L├│pez LM, Bakker RRC. Literature Review of Physical and Chemical Pretreatment Process for Lignocellulosic Biomass. Food & Biobased Research 2010;Accessed on 9 May 2011http://www.ecn.nl/publicaties/PdfFetch.aspx?nr=ECNE-- 10-013
[8] Zeng J, Singh D, Chen S. Biological pretreatment of wheat straw by Phanerochaete chrysosporium supplemented with inorganic salts. Bioresource Technology 2011;102; 3206-3214.
[9] Champagne P, Li C. Enzymatic hydrolysis of cellulosic municipal wastewater treatment process residuals as feedstocks for the recovery of simple sugars. Bioresource Technology 2009;100;5700-5706.
[10] Kuila A, Mukhopadhyay M, Tuli DK., Banerjee R. Production of ethanol from lignicellulosics: an enzymatic venture. Experimental and Clinical Sciences Journal 2011;85-96;1611-2156.