Effect of alkaline and autohydrolysis processes on the purity of obtained hemicelluloses from corn stalks.
A study of the potential of autohydrolysis and alkaline extraction processes from corn stalks was performed for high purity hemicellulose extraction. The influence of process parameters on the purity of obtained hemicelluloses was analyzed. An experimental design was developed for the autohydrolysis treatments to determine the optimal conditions to solubilize the hemicelluloses with lowest content in contaminants. On the other hand, alkaline extraction, including raw material pretreatment (dewaxing and delignification step) was carried out analyzing the effectiveness of this processes for maximum pure hemicellulose recovery. The maximum yield (54% of the raw material hemicelluloses) and the best physicochemical properties (highest hemicellulose content free of lignin) were obtained with these pretreatments in alkaline extraction. Moreover, the effect of lignin removal by sulfuric acid from the autohydrolysis liquors before hemicellulose precipitation was studied. This purification step has allowed to obtain lignin-free autohydrolysis hemicellulose but with the presence of sulfur as predominant contaminant.
Chemical and Environmental Engineering Department, University of the Basque Country, Plaza Europa 1, 20018 Donostia-San Sebastián, Spain.
Itziar
I
Egüés
Cristina
C
Sanchez
Iñaki
I
Mondragon
Jalel
J
Labidi
D019342:Acetic Acid / Q000032:analysis; D011232:Chemical Precipitation / Q000187:drug effects; D004602:Elements; D006863:Hydrogen-Ion Concentration / Q000187:drug effects; D006868:Hydrolysis / Q000187:drug effects; D008031:Lignin / Q000032:analysis; D008970:Molecular Weight; D009005:Monosaccharides / Q000032:analysis; D011134:Polysaccharides / Q000302:isolation & purification*; D012972:Sodium Hydroxide / Q000494:pharmacology*; D012995:Solubility / Q000187:drug effects; D013054:Spectrophotometry, Atomic; D017550:Spectroscopy, Fourier Transform Infrared; D013818:Thermogravimetry; D014866:Waste Products / Q000032:analysis*; D003313:Zea mays / Q000737:chemistry* / Q000187:drug effects
D004602:Elements; D009005:Monosaccharides; D011134:Polysaccharides; D014866:Waste Products; D012972:Sodium Hydroxide; C007916:hemicellulose; D008031:Lignin; D019342:Acetic Acid