Conclusion
This work demonstrates that coffee extract residue can be used
for the generation of two distinct products, viz. ethanol and activated
carbons. The prospective end-use of abundant waste and
waste feedstocks of lignocellulosic biomass is attractive and
promising for the production of both fuel and adsorbent.
A straightforward method for ethanol production by saccharomyces
cerevisiae using different amounts, temperatures, substrate
loading, fermentation time and with or without mild treatments
was carried out. Higher yields of ethanol were obtained as the cell
walls of the biomass with small particle sizes were exposed for the
direct hydrolysis and fermentation. Based on the experiments, the
optimal fermentation was determined as follows; temperature
30 C, yeast 30 mg g1
CER and a combined aqueous phase after
cooking and solid residue fermentation after treatment. The result
also conveys that there is a potential for ethanol production if
conditions for further extraction of the hexose and pentose sugars
are increased.
Highly developed mesoporous and microporous structures of
activated carbons were prepared by both chemical and physical
activation of the coffee extract residue. Depending on the activation
method, concentration of acid and pyrolysis temperature, different