Coffee is one of the most universally consumed beverages. The world produces 60 million tons of spent coffee grounds (SCGs) as waste per year. Biodiesel made from SCGs is an eco-friendly alternative fuel but proves difficult to produce. 1,8-Diazabicyclo[ 5.4.0]undec-7- ene (DBU) was used as both a solvent and a catalyst with methanol to determine the efficiency of biodiesel production from SCGs. The process was completed by extracting coffee oil from acid-washed spent coffee grounds (AWSCGs) using hexane. The two extraction methods that were explored were Soxhlet and agitation. DBU is an interesting choice as a solvent and a catalyst because of its ability to change polarities when exposed to carbon dioxide or nitrogen. However, it was shown through experimentation that the product had large crystals and copious amounts of glycerol while producing negligible amounts of biodiesel. Both AWSCGs and regular SCGs were tested along with variations of DBU and methanol volumes, but the results show an insufficient yield in each case. From this, it can be concluded that using DBU as a solvent and catalyst with methanol and coffee oil for production of biodiesel is ineffective. Future experiments to convert SCGs into biodiesel should look for other catalysts and ways to optimize reaction conditions for biodiesel production.
Stepherson, Christopher; Karras, Pericles; Ha, Amy; Nguyen, Phuc Tan; Pati, Abigail; Hejazi, Jacob; Hussain, Soheil; De Young, Elizabeth; and Fu, Shuaicheng
"Biodiesel Transesterification of Spent Coffee Grounds Using DBU as a Catalyst: Using DBU to Make Biodiesel from Coffee Grounds,"
The Journal of Purdue Undergraduate Research:
Vol. 13, Article 10.