Scientists Find a Smarter Way To Turn Used Coffee Grounds Into Clean Fuel

Researchers at Universitat Rovira i Virgili have optimized an oil-extraction process for spent coffee grounds, recovering ~90% of oil at 45°C for 60 minutes with n-hexane at a ratio of 35 mL per gram of dry residue, producing cleaner oil (0.3% impurities vs. 3.9% via standard Soxhlet extraction) suitable for biodiesel conversion while preserving remaining cellulose and hemicellulose for further biorefinery use.

Industrial scaling and widespread adoption will require commercial feasibility assessments and biorefinery infrastructure development.