Effects of inorganic salts on pretreatment of Miscanthus straw

This study focused on the effects of five inorganic salts, NaCl, KCl, CaCl2, ZnCl2, and FeCl3, on the pretreatment of Miscanthus straw for sugar recovery and enzymatic digestibility. In the results, all of the salts reduced the hemicellulose content in the straw. Most notably, FeCl3 effected almost 100% xylan removal. Overall, the trivalent salts, which include FeCl3, had an especially significant influence on enzymatic digestibility of Miscanthus straw compared with the di- and mono-valent inorganic salts, which had relatively only minor effects. The salt impacts were in the following order: FeCl3 > ZnCl2 > CaCl2 > KCl > NaCl. Under the pretreatment condition of 0.5% FeCl3 at 200 °C for 15 min, 100% xylan removal and 71.6% enzymatic digestibility were obtained. Nevertheless, ZnCl2 get the better effect on total glucose content than that of FeCl3.