Abstract:
Collection of 10 weed samples (height > 1m) from the exploration in 8 provinces including Nakompathom, Bangkok, Samuthprakarn, Chacheongsao, Chonburi, Pathumtani, Lumphun, and Nakomrachasnma found ten weeds including Coix aquatica, Imperata cylindrica, Panicum maximum, Pennisetum polystachyon, Pennisetum purpureum, Phragmites karka, Saccharum spontaneum, Sorghum propinquum, Thysanolaena maxima, and Typha angustifolia. The study on biomass yield, moisture content at harvest in plant, biomass composition, sulfur content, ash content, and heating value revealed that some of these weeds were found to have suitable properties as energy crops for direct combustion. T. maxima, S. spontaneum, and I. cylindrica had high biomass yields (0.6-3.0 kg/m²), low sulfur content (0.09-12%), low ash content (4.95-6.27%), high heating value (17.43-18.79 MJ/kg), and moisture content at harvest in plant between 58.84-73.12%. Ethanol production of 10 weeds using simultaneous saccharification and fermentation process (SSF) with cellulases from thermotolerant fungus, Acrophialophora sp. UV10-2, and thermotolerant yeast, Kluyveromyces marxianus NRRL Y-1109, was performed under shaking condition (125 rpm), 40 °c, and pH 5.0. The maximum ethanol yield was found to be 4.9 g/L or 0.16 g/g substrate (%conversion = 48.48%) for c. aquatica. When SSF process was performed in large scale, 5L femnentor (batch process), the ethanol yield was 8.8 g/L or 0.18 g/g substrate (%conversion = 54.55%). After distilling by simple distillation method, the higher concentration of ethanol was obtained 96.8 g/L (11.02 fold increased).