61A-2 |
Xylose from the hydrolysis of sugar cane bagasse using sulphuric acid at autoclave pressure |
J. A. RAMÍREZ, R. Aguilar, and M. Vázquez. Dept. of Food Science & Technology, Univ. Autónoma de Tamaulipas, UAM Reynosa-Aztlán, Reynosa, Tamaulipas, 88700, Mexico Sugar cane bagasse is a lignocellulosic material with high content in xylose. The xylose production by acid hydrolysis is interesting because xylose can be used in the biotechnological production of xylitol, a polyol with important applications as sweetener. Xylitol has important advantages over glucose or saccharose, such as anticarcinogenicity, low caloric value and negative heat of dissolution. The objective of this work was to study the xylose production from sugar cane bagasse by sulphuric acid hydrolysis at 122 ºC to obtain solutions with a maximum xylose concentration and minimum concentration of furfural and acetic acid (growth inhibitors). The effect of several sulphuric acid concentrations (2,4 and 6%) and several reaction times (0-300 min) were evaluated. Kinetic models were developed to explain the time course of xylose, acetic acid and furfural generated in the hydrolysis. Sugar cane bagasse was collected in a local industry (Ingenio Azucarero de Mante, Tamaulipas, México). The sugar cane bagasse were air dried, milled, screened to select the fraction of particles with a size lower than 0.5 mm, homogenized in a single lot and stored until needed. Moisture was determined gravimetrically, xylose and acetic acid were determined by HPLC and furfural was determined by UV-Vis spectrometry. It was observed that the xylose concentration reached a maximum value and then decreased with the reaction time at 122ºC. This suggests that decomposition reactions exist, conducting probably to furfural. The models allowed to obtain a maximum xylose concentration using 2% of sulphuric acid at 24 min. In these conditions, hydrolysates with 21.6 g xylose/L, 0.52 g furfural/L and 3.65 acetic acid g/L were obtained. The hydrolysates contained low concentrations of furfural and acetic acid. Therefore, these solutions can be used as media for fermentation media for xylitol production.
Session 61A, Carbohydrate
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