Effects of operation conditions on enzymatic hydrolysis of high-solid rice straw

In the present work, the performances of high-solids enzymatic hydrolysis of rice straw were experimentally studied. Moreover, the heat flow and weight loss of the pre- and post-hydrolysis of rice straw were measured by the simultaneous thermogravimetric analyzer. It is found that the output and yield of reducing sugar initially increased and then reduced with an increase of supplied water, hydrolysis temperature and substrate mesh, while the cellulose content in residual substrate had an opposite trends. Furthermore, a high enzyme loading resulted in a constant saccharification efficiency of cellulose. The output and yield of the sugar, 77.7 mg/(g substrate) and 0.44 g/g, were respectively achieved under the optimal conditions of the supplied water of 1.0 ml/(g substrate), enzymolysis temperature of 50 °C, rice straw of 60 mesh and the cellulase dosage of 2.0 mg/(g substrate). Simultaneous thermogravimetric analysis on the rice straw indicates that the chemical compositions of rice straw changed after enzymolysis. Highlights: Operation conditions on enzymatic hydrolysis in high-solid state were investigated. Optimal conditions of enzymatic hydrolysis in high-solid state were obtained. TGA of substrate were conducted to detect biomass combustion enthalpy. © 2012 Hydrogen Energy Publications, LLC.