The sequential co-production ofbioethanol and biodiesel from spent coffee grounds was investigated.
The direct conversion ofbioethanol from spent coffee grounds was not found tobeadesirable option
because of the relatively slow enzymatic saccharificationbehavior inthe presence oftriglycerides and
the free fatty acids (FFAs)found toexist inthe raw materials.Simil arly,the direct transformation of
the spent coffee grounds into ethanol without firstextracting lipids was not found tobeafeasib lealter-
native. However,the crude lipids extracted from the spent coffee grounds were themselves converted
into fatty acid methyl ester (FAME) and fatty acid ethyl ester (FAEE)via the non-catalytic biodiesel
transesterification reaction.The yields ofbioethanol and biodiesel were 0.46 gg1 and 97.5 ±0.5%,which
were calculated based onconsumed sugar and lipids extracted from spent coffee grounds respectively.
Thus, this study clearly validated our theory that spent coffee grounds could beastrong candidate for
the production ofbioethanol and biodiesel.