Comparing Ecuadorian Cocoa Mucilage-Based Bio-Ethanol and Commercial Fuels Toward Their Performance and Environmental Impacts in Internal Combustion Engines

Abstract

In response to Ecuador’s need for sustainable and locally sourced transport fuels, this study evaluates the energetic and environmental performance of a biofuel (bioethanol-based) derived from the mucilage of the CCN51 cocoa variety, analyzed under controlled operating conditions in an internal combustion engine. Bioethanol obtained from this feedstock was blended with Ecuador’s commercial Extra gasoline to produce an E5 formulation, experimentally compared with Extra (85 RON) and Super (92 RON) fuels. Physicochemical analysis following NTE INEN 2102 revealed a research octane number of 85.8 and a lower heating value of 45.22 MJ/kg. Static tests performed on a Hyundai i10 engine (2021) at 700 and 2500 rpm showed that the E5 blend achieved higher energy and exergy efficiencies (21.17% and 64.12%, respectively) than Extra gasoline, approaching Super performance. Environmentally, the E5–CCN51 blend reduced carbon monoxide (CO) by ~10–15% and unburned hydrocarbons (HC) by ~5–8%, while maintaining λ ≈ 1. Variations in O2 and CO2 confirmed enhanced oxidation and more complete combustion. Overall, these findings demonstrate the technical feasibility and environmental relevance of CCN51 cocoa mucilage as a sustainable ethanol source, contributing to cleaner combustion, circular bioeconomy promotion, and energy resilience in tropical developing regions.