Sujitra Wongkasemjit
Chulalongkorn University, Thailand
Received Date: 2022-05-17 | Accepted Date: 2022-05-23 | Published Date: 2022-05-30Napier grass (Pennisetum purpureum), Tiger grass (Thysanolaena maxima), Mission grass (Pennisetum polystachyon), Kans grass (Saccharum spontaneum) and Giant reed (Arundo donax) were locally collected to test as bioethanol feedstock. All grasses, showing high cellulose and hemicellulose compositions, were treated by a twostage microwave/ chemical pretreatment method. The optimum conditions of the pretreatment were investigated and the maximum monomeric sugar yields were compared. The microwave-assisted NaOH and H2SO4 with 15:1 liquid to solid ratio were studied by varying catalyst concentration, temperature, and time to maximize the amount of the obtained monomeric sugar. The maximum monomeric sugars released from microwave-assisted NaOH pretreatment were 5.57 g (at 600C/10 min, 0.5%(w/v) NaOH for Napier grass), 6.45 g (at 1400C/15 min, 1%(w/v) NaOH for Tiger grass), 6.56 g (at 1200C/10 min, 3% (w/v) NaOH for Mission grass), 6.78 g (at 800C/5 min, 5% (w/v) NaOH for Kans grass), and 6.84 g (at 1200C/5 min, 5% (w/v) NaOH for Giant reed) per 100 g biomass, while maximum monomeric sugars from microwaveassisted H2SO4 pretreatment were 42.03 g (at 1600C/15 min, 1% (w/v) H2SO4 for Napier grass), 30.37 g (at 2000C/5 min, 0.5% (w/v) H2SO4 for Tiger grass), 34.34 g (at 2000C/5 min, 1%(w/v) H2SO4 for Mission grass), 33.76 g (at 2000C/10 min, 0.5% (w/v) H2SO4 for Kans grass), and 31.91 g (at 1800C/30 min, 0.5% (w/v) H2SO4 for Giant reed) per 100 g biomass.