Hierarchical economic potential approach for techno-economic evaluation of bioethanol production from palm empty fruit bunches

• 4-Level economic potential (EP) for the evaluation of techno-economic feasibility.
• Case studies on bioethanol production from EFB with and without jet fuel.
• Bioethanol production with jet fuel shows higher economic viability.
• 4-Level EP can be a systematic approach for techno-economic analysis.

A hierarchical four-level approach to determine economic potential (4-level EP) is proposed for preliminary techno-economic analysis of new processes. The 4-level EP includes input/output structure, process flow structure, heat integration (HI), and economic feasibility. Two case studies on a 30.2 t/d (or 12.7 million l/yr) bioethanol plant with and without jet fuel production from palm empty fruit bunches (EFB) were investigated by applying the 4-level EP. The plant flowsheet was established based on experiments in a 0.1 t/d pilot plant, including sequential dilute acid and alkali pretreatment, and separate hydrolysis and fermentation (SHF). EP approached a more reliable value through the hierarchical 4-level EP. The heating energy was reduced considerably by HI. The product value was estimated at $0.8–$1.3/kg of equivalent bioethanol. It was suggested through sensitivity analysis that a large plant size, enhanced production yields, and capital cost reduction were necessary for the lignocellulosic bioethanol production to be profitable.