Agricultural Waste Management Through Energy Producing Biorefineries: The Colombian Case

The energy demand is increasing dramatically during last years. Due to this, biomass has been considered as an interesting alternative for renewable energy production. The objective of this work was to evaluate the production of bioethanol, biogas and electricity for using plantain pseudostem and rice husk produced as agricultural wastes in Colombia through a biorefinery scheme. The chemical characterization of these residues was carried out to get the input data for the conceptual design of fermentation, anaerobic digestion and combustion processes. Finally a techno-economic evaluation was developed to compare the potential of each process. The rice husk biorefinery showed higher yields of biogas and electricity compared to the plantain pseudostem case. In general terms, it was observed that production costs of bioethanol (0.48 USD/kg against 0.82 USD/kg), biogas (0.27 USD/m(3) against 0.56 USD/m(3)) and electricity (0.02 USD/kW against 0.03 USD/kW) were kept lower under a biorefinery approach compared to the stand-alone processes for the rice husk case. For plantain case all the results were negative both for stand alone and biorefinery cases. This work concluded that it is possible to take advantage of some agricultural wastes generated in Colombia under biorefinery scheme to produce bioethanol, biogas and electricity as source of energy to supply a fraction of the energetic demand in this country.