# Thermophysical properties of 5-methylfurfural with alcohol additives: Toward efficient and sustainable biofuel blends

## TL;DR

This study explores how adding alcohols to 5-methylfurfural can improve biofuel properties for better engine performance and sustainability.

## Contribution

The study reveals how hydrogen bonding and alcohol chain length affect the thermophysical properties of MFF blends.

## Key findings

- Short-chain alcohols enhance volatility and molecular packing in MFF blends.
- Long-chain alcohols improve miscibility and stability for compatibility with conventional fuels.
- Molecular dynamics simulations align closely with experimental measurements of blend properties.

## Abstract

The transition toward sustainable energy systems requires renewable fuel alternatives with optimized combustion performance and reduced emissions. 5-Methylfurfural (MFF), a lignocellulosic biomass-derived furanic compound, has emerged as a promising biofuel precursor and blending. In this study, we investigated the thermophysical properties and molecular interactions of binary mixtures of MFF with short-to medium-chain 2-alkanols (C3–C6), combining experimental measurements of density and viscosity with molecular dynamics (MD) simulations. Our findings reveal strong hydrogen-bond interactions between MFF’s aldehyde group and the hydroxyl groups of short-chain alcohols, leading to compact molecular packing, enhanced volatility, and improved combustion efficiency. Conversely, longer-chain alcohols introduce steric hindrance that disrupts hydrogen-bonding networks, increasing free volume and diffusivity, thereby influencing ignition delay and miscibility with conventional fuels. These results provide molecular-level insights into customizing viscosity, density, and volatility of renewable fuel blends, thereby enabling the design of advanced biofuels with improved engine compatibility and environmental performance.

•Hydrogen bonding governs MFF/alcohol blend thermophysical behavior•Short-chain alcohols enhance volatility and packing for SI engines•Long-chain alcohols improve miscibility and stability for CI engines•Experimental and MD results show strong quantitative agreement

Hydrogen bonding governs MFF/alcohol blend thermophysical behavior

Short-chain alcohols enhance volatility and packing for SI engines

Long-chain alcohols improve miscibility and stability for CI engines

Experimental and MD results show strong quantitative agreement

Electrochemical energy production; Computational molecular modelling; Energy materials