Process Simulation of Fuel Ethanol Production from Lignocellulosics using Aspen Plus

Fuel ethanol production has become one of the most studied processes in the last two decades because of the need to decrease its production cost and improve its energetic performance. The most promising raw material is lignocellulosic biomass because of its negligible cost and high availability. On the other hand, most research has focused on single steps and has not considered the whole process design. Aspen Plus allowed designing this kind of process while considering relevant aspects such as raw material composition and kinetic models of chemical and biological transformation. hi this study fuel ethanol from rice hulls has been simulated considering the kinetic parameters for acid pretreatment, detoxification, and fermentation with the aim of assessing the energy performance of the process. In addition, the economic evaluation was accomplished using Aspen Process Economic Analyzer with the objective of calculating the production cost. It was found that the dilute acid pretreatment had a higher ethanol yield (347.25 L/t) and lower energy consumption (86.75 MJ/L) than liquid hot water pretreatment. However, the latter pretreatment had a lower production cost (US$0.4367/L); although when energy cogeneration and electricity sales were included in the analysis, dilute acid pretreatment became the most economic technology with a lower production cost (US$0.1918/L).