(602bf) Pretreatment of Wheat Straw Using the H2O-SO2 System At Elevated Temperatures

Efficient pretreatment process is important for complete enzymatic conversion of lignocellulosic material. In this work, sulphur dioxide (SO₂) dissolved in hot water was demonstrated as an efficient system for the pretreatment of wheat straw. The xylose and total products yields were up to 61.05% and 93.89%, respectively, based on the mass of lignocellulose in wheat straw. Kinetic modeling based on experimental data suggested that the activation energies of hemicellulose conversion and xylose dehydration were 7.8 and 9.0 kJ/mol. FT-IR spectra of the residual solid after treatment show that the hemicellulosic components were converted, the hydrogen bonds in cellulose were broken, but the lignin structure has no obvious changes. Importantly, SO₂ could be recovered from product mixture by steam stripping to make SO₂ reusable. In this work, we provide an efficient and environmentally friendly way to pre-treat wheat straw hemicellulose in SO₂+H₂O system.

This work was supported by the National Natural Science Foundation of China (21176020), the Beijing Natural Science Foundation (2082017), and the Program for New Century Excellent Talents in University (NCET-08-0710)