The Government of India has mandated biofuel blending in automotive fuels to reduce crude oil imports and support the national economy. As part of this initiative, Oil Marketing Companies (OMCs) have begun nationwide blending of E20 fuel (20% ethanol in petrol). Ethanol supply is expected to exceed demand by the end of 2025 due to initiatives like the Pradhan Mantri JI-VAN Yojana (ethanol from waste grains). Alternative applications for ethanol are being explored; one promising approach is its use as a co-blend with diesel fuel. However, ethanol’s low cetane number and poor lubricity present challenges for direct use in diesel engines without modifications. This study explores ethanol diesel (ED) blends for unmodified diesel engines. ED blends demonstrated reduced emissions while maintaining performance comparable to conventional diesel.
To further address concerns related to materials compatibility of ED blends with fuel system components, particularly plastomers (e.g., hoses, seals, and gaskets) that may impact engine durability, a detailed study was conducted using commonly used plastomers such as Fluoroelastomer (FKM), Nitrile Butadiene (NBR), Hydrogenated Nitrile Butadiene (HNBR), Fluorosilicone (FVMQ), and Polyamide 66 (PA66) in accordance with the SAE J1748 standard. Test specimens were immersed in ethanol-diesel blends and conventional diesel at 55°C for extended durations (1008 hours for elastomers and 3024 hours for plastics). Key physical properties such as visual appearance, weight, volume, tensile strength, elongation, impact strength, and hardness were measured before and after the immersion tests. The results revealed that FKM and FVMQ demonstrated comparable durability when exposed to ethanol-diesel blends vis-à-vis diesel, whereas NBR and HNBR performed better only in conventional diesel. Scanning Electron Microscopy (SEM) analysis of the specimens showed surface degradation patterns in NBR and HNBR. These findings provide essential insights supporting the feasibility of integrating ethanol blended diesel into India’s automotive diesel fuel system.