Effects of acid hydrolysis in production of monosaccharide and cellulose pulp from corn stalks: An experimental and...

In this work, acid hydrolysis of hemicellulose and cellulose in corn stalk (CS) was systematically studied by using both experimental and theoretical methods. The results indicate that the polysaccharide units of hemicellulose undergo a conversion from intermolecular to intramolecular hydrogen bonds in the hydrolysis process. This exothermic process could effectively facilitate the hydrolysis of hemicellulose thermodynamically. Moreover, a linear correlation between hydrogen bonded fraction of solid hydrolysis product and the dosage of sulfuric acid was found at our hydrolysis condition. Analysis of hydrolysis product composition indicates that xylose yield of 298.17 g/kg CS was obtained from the hydrolysis of hemicelluloses in 1 % w/w sulfuric acid solution at 150 °C for 3 hours. Glucose yield of 185.02 g/kg CS was obtained from the hydrolysis of celluloses in 5 % w/w sulfuric acid solution under the same conditions. Such results indicate that high yields of xylose and glucose can not be simultaneously obtained via hydrolysis of CS in a sulfuric acid solution at our experimental condition. Meanwhile, analytical results indicate that cellulose could be fully preserved, and about 60 % hemicellulose and 20 % lignin could be removed during hydrolysis of CS in 0.01 % sulfuric acid solution. Such results indicate a good potential for production of cellulose pulp via the alkaline sulfite cooking of these solid hydrolysis products. Paper sheet showed a superior performance when compared with hydrolysis of CS in water, as supported by tensile index 50.1 N·m/g, tear index 10.35 m²/g, burst index 6.37 kPa·m²/g, and ring crush index 4.74 N·m/g. Our findings would be very useful to guide the search for full utilization of cellulose and hemicellulose of CS in industrial scale.