ENHANCED DELIGNIFICATION OF CORN STRAW WITH ALKALINE PRETREATMENT AT MILD TEMPERATURE

The lignocellulosic substrate bioconversion to produce fuel is very potential to be developed in the future. Converting cellulose to simple sugars requires a suitable and inexpensive preliminary treatment. This study aimed to investigate the use of alkali materials as chemicals suitable to delignify corn straw powder. The research was conducted to choose the chemical type for delignification, namely: NaOH, Ca(OH)2, NH3 (NH4OH), and Hydrazine. In the next step, the concentration of the delignification solution for corn straw powder was determined at material/chemical ratio of 1:10 (w/v) and soaked for 8 h at room temperature. The tested alkaline solution concentrations were varied from 0, 2, 4, 6, to 8% (w/v). The pre- and post pretreatments affected the yield of ?-cellulose, relative degree crystallinity by an X-Ray Diffraction (XRD), functional groups using a Fourier Transform Infra-Red (FT-IR) and surface morphology using a Scanning Electron Microscopy (SEM). Corn straw substrate in the best treatment will applied in the production of cellulase enzymes. The results showed that NaOH is the best used as a delignifying agent with the highest level of cellulose and the lowest lignin, namely 61.45% and 1.09%, respectively. The NaOH solution at the concentration of 4% gives optimal results, with cellulose content 65.46%, hemicellulose 14.58%, and lignin 8.66%. Based on FTIR, XRD and SEM analysis showed that alkali pretreatment, especially with NaOH solution, gives the result in which the corn straw cellulose structure becomes swelling.