关键词: 橡子壳, 酸法预处理, 酶水解, 木质纤维素, 纤维结构

Abstract: The effect of dilute acid pretreatment on the composition and enzymatic hydrolysis rate of Sawtooth Oak (Quercus acutissima) shells was investigated. And the fiber structures of pretreated residues were studied with scanning electron microscopy (SEM), infrared spectra (IR) and X-ray diffraction spectrum (XRD). Results showed that after pretreatment at room temperature with 2% H₂SO₄, the contents of hemicellulose and lignin were reduced by 21.6% and 6.6%, respectively. The enzymatic hydrolysis yield reached 71.4% from 42.8%, and total glucose yield was 71.2% which was 66.4% more than that of untreated oak shell. After pretreatment at 121 ℃ (0.15 MPa) for 1 h, the contents of hemicellulose and lignin were reduced by 84.6% and 24.5%, respectively. The enzymatic hydrolysis yield reached 72.1% which was 68.5% more than that of untreated oak shell. Because of the high cellulose loss, the glucose yield improvement was not so obvious. The fiber surface and pore volume increased and the crystallinity of cellulose decreased, which are favorable to increase the enzymatic hydrolysis rate.

Key words: Oak shell, dilute acid pretreatment, enzymatic hydrolysis, lignocellulose, cellulose structure