Fractionation of wheat straw by atmospheric acetic acid process.
Fractionation of wheat straw was investigated using an atmospheric acetic acid process. Under the typical conditions of 90% (v/v) aqueous AcOH, 4% H(2)SO(4) (w/w, on straw), ratio of liquor to straw (L/S) 10 (v/w), pulping temperature 105 degrees C, and pulping time 3h, wheat straw was fractionated to pulp (cellulose), lignin and monosaccharides mainly from hemicellulose with yields of approximately 50%, 15% and 35%, respectively. Acetic acid pulp from the straw had an acceptable strength for paper and could be bleached to a high brightness over 85% with a short bleaching sequence. Acetic acid pulp was also a potential feedstock for fuels and chemicals. The acetic acid process separated pentose and hexose in wheat straw to a large extent. Most of the pentose (xylan) was dissolved, whereas the hexose (glucan) remained in the pulp. Approximately 30% of carbohydrates in wheat straw were hydrolyzed to monosaccharides during acetic acid pulping, of which xylose accounted for 70% and glucose for 12%. The acetic acid lignin from wheat straw showed relatively lower molecular weight and fusibility, which made the lignin a promising raw material for many products, such as adhesive and molded products.
Pan
Xuejun
X
Institute of Material Science and Chemical Engineering, Tianjin University of Science and Technology, 1038 Dagu Nanlu, Tianjin 300222, China. xpan@interchange.ubc.ca
Sano
Yoshihiro
Y
D019342:Acetic Acid / Q000737:chemistry*; D002241:Carbohydrates / Q000302:isolation & purification; D005591:Chemical Fractionation / Q000379:methods*; D007564:Japan; D008031:Lignin / Q000032:analysis / Q000737:chemistry / Q000302:isolation & purification; D010209:Paper; D018547:Plant Stems / Q000737:chemistry*; D014908:Triticum
D002241:Carbohydrates; D008031:Lignin; D019342:Acetic Acid