Bioethanol scheduling production with a combination of oil palm trunks and empty fruit bunches

Abstract

Bioethanol production from lignocellulosic biomass is a combination of batch and continuous processes. Such processes mainly consist of pretreatment to recover the highest possible content of cellulose during fermentation using hydrolysis and yeast to convert cellulose into bioethanol with purification to produce the required level of biofuel concentrate. This study aims to develop a simulation model for producing bioethanol from oil palm trunks (OPTs) and empty fruit bunches (EFBs), involving the batch scheduling of pretreatment and fermentation to produce 99.0% wt. bioethanol at 10,000 L/day. Furthermore, OPTs and EFBs offer the flexibility to change feedstocks which also affects the schedule. In this study, Aspen Plus calculates the raw materials and utilities required using the Aspen Batch Process Developer (ABPD) and then schedules the batch operation. To produce bioethanol, the results indicate that OPTs and EFBs with a ratio of 1:1 should be fed 24,000 kg-OPTs/day and 24,000 kg-EFBs/day to produce the required amount of bioethanol. The pretreatment section should be operated in two cycles and fed into a fermenter every 240 min. Moreover, to schedule the fermentation process, ideally, 15 parallel fermenters should be used to ensure a continuous supply for purification. Extractive distillation and pervaporation technologies are proposed in this study, consuming 16.78 and 19.24 MJ/L, respectively, to produce bioethanol in the targeted amount.