RESPONSE SURFACE OPTIMIZATION STUDIES OF THE ACID-CATALYSED HYDROLYSIS OF HAZELNUT SHELLS

Abstract

The utilization of hazelnut shells as a renewable and low cost lignocellulosic biomass for bioethanol production requires the optimization of hydrolysis step. A comprehensive, experimental and modeling study on the acid hydrolysis of hazelnut shells is reported at variable sulfuric acid concentrations (0.1-0.7 M) and temperatures (100-120 oC) where a solid to liquid ratio is 1/7. The influence of the acid concentration, the temperature and reaction time on reducing sugar as well as the degradation product furan levels were evaluated by performing a 33 full factorial experimental design. The analysis of the optimum combinations of independent variables indicates that a high acid concentration and a moderate temperature may provide the optimum acid hydrolysis conditions for hazelnut shells.