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.