Spent coffee grounds to biodiesel: Opportunities, challenges, and insights from an experimental study

Spent coffee grounds (SCG) represent an attractive and sustainable feedstock for biofuel production due to their high lipid content and abundance as a waste product. This study examines the step-by-step production of biodiesel from espresso SCG, focusing on several opportunities and challenges associated with each conversion step. The results indicated that oil degumming and neutralization, prior to alkali- catalyzed transesterification, were promising compared to acid-catalyzed esterification, which was deemed insufficient. Under the selected conditions, 70.16% of biodiesel yield was obtained. These findings underscore the feasibility of utilizing SCG as a renewable resource for biodiesel synthesis.