Bioethanol blend deployment readiness in humid tropical Bangladesh using a multicriteria framework

Abstract Low-level ethanol blending in gasoline may reduce petroleum dependence in humid-tropical economies, but deployment requires evidence on fuel handling, storage stability, material compatibility, emissions, and feedstock supply. This study develops the Humid Tropical Ethanol Blend Readiness Index (HT-EBRI) and applies it to Bangladeshi petrol and high-octane gasoline blends from E5 to E20. The assessment combines physicochemical properties, copper-strip corrosion tests, spark-ignition emission observations, feedstock mass balances, four comparative multicriteria methods, and Monte Carlo analysis. P-E5 achieved the highest evidence-complete HT-EBRI score of 85.7 and ranked first in 91.7% of 20,000 simulations. O-E10 produced the largest CO and HC reductions at 3000 rpm; the reductions were 80.0% and 91.7%, respectively. All blends retained a 1a copper-strip rating at 50 °C. E10–E20 shifted to 3a only at 100 °C. Broken rice and dry maize met the screened feedstock requirement, and molasses supplied only 38.6% of demand. HT-EBRI provides a blend-level framework for comparing deployment readiness and identifies E5 as the leading candidate for a bounded pilot under humid-tropical conditions. Unlike prior feedstock- or technology-level MCDA studies, HT-EBRI offers a unique final-blend, evidence-tiered screen that combines local logistics, humid-storage effects, corrosion signals, provisional emissions, energy penalties, and feedstock pressure, and assigns a full readiness score once all critical evidence meets the required standard.