Abstract:
A two-stage biomass pretreatment process – a combination of ammonium hydroxide (NH₄OH) and phosphoric acid (H₃PO₄) pretreatments – is experimentally studied via microwave hydrothermal treatment to remove lignin and to produce monomeric sugars from Miscanthus Sinensis grown is Cha-Chueng-Sao province, Thailand. Effects of factors affecting the sugar yield are investigated. The results indicate that the optimal conditions, for the NH₄OH pretreatment, are found to be 1.0% (w/v) NH₄OH, 15:1 liquid-to-solid ratio (LSR) at 120°C temperature for 15 min pretreatment time; and for the H₃PO₄ pretreatment, 3.0% (w/v) H₃PO₄, 15:1 LSR at 140°C for 30 min. Total monomeric sugar yields obtained are 2.9, 62.3, and 71.6 g/100g biomass for the NH₄OH, the H₃PO₄, the two-stage pretreatments, respectively. The structural change of the pretreated miscanthus is elucidated using Fourier transform infrared spectroscopy (FTIR).
