RESUMO
Microwave assisted acid hydrolysis (H2SO4 and HCl with >0.5â¯mol/L) to produce bioethanol from sago pith waste (SPW) was studied. The energy consumption for microwave hydrolysis at different energy inputs and acid concentration were calculated. The overall energy consumption for bioethanol fuel production from SPW was assessed. A maximum of 88% glucose yield and 80% ethanol yield (3.1â¯g ethanol per 10â¯g SPW) were obtained using 1.0â¯mol/L H2SO4. Microwave hydrolysis using 1.0â¯mol/L H2SO4 consumed the minimum energy of 8.1â¯kJ to produce 1â¯g glucose from SPW when energy input was fixed at 54â¯kJ (900â¯W for 1â¯min). In general, 1â¯g glucose can produce 16â¯kJ. The overall energy consumption for fuel grade bioethanol production from SPW was 31.77â¯kJ per g ethanol, which was slightly higher than the lower heating values of ethanol (26.74â¯kJ/g ethanol).