Extraction of Oil from Fresh and Spent Coffee Extracts from Assorted Geographies

The exponential growth in coffee consumption and the extensive coffeehouse presence in the United States have led to a significant increase in spent coffee waste production. This waste contributes to environmental degradation, particularly in the form of methane emissions in landfills. To address this issue and explore eco-friendly alternatives, this study investigates the oil content in spent coffee grounds (SCG) from different geographical regions as a potential source for biofuel production. Fifteen diverse coffee samples were collected from various global locations and analyzed for their oil content. Fresh Coffee Grounds (FCG) and Spent Coffee Grounds (SCG) were extracted using isopropyl alcohol, and the oil content was measured gravimetrically. South American coffees from Peru, Colombia, and Brazil exhibited higher oil levels in comparison to other regions. To improve the quality of extracted oil for biofuel applications, saponification was employed to transform excess triglycerides into glycerol and crude soap, yielding a mixture of fatty acid methyl esters containing oil. Further scaling up the extraction process demonstrated that South American coffee varieties had significantly higher oil levels compared to American coffee. The findings provide valuable insights for selecting suitable coffee waste sources for biofuel production, especially from high-oil-content South American coffee varieties. Future research may involve detailed chemical composition analysis through GC-MS to identify key fatty acids like linoleic, palmitic, and oleic acid for optimal diesel fuel production. Collaboration with coffee chains to assess their spent coffee waste could pave the way for a practical, environmentally friendly solution, making a compelling economic case for green biofuel