초록
<P><B>Abstract</B></P> <P>The methanogenic and acidogenic potentials of six different agroindustrial residues, i.e. of fruit pulps and brewery residues, were determined. For all substrates, the methanogenic conversion yield was systematically higher than the acidogenic one in Chemical Oxygen Demand (COD) terms, ranging from 0.46 to 0.87 g<SUB>COD_CH4</SUB>/<SUB>gCOD_substrate_fed</SUB> and from 0.24 to 0.56 g<SUB>COD_tVFA</SUB>/g<SUB>COD_substrate_fed</SUB>, respectively. During methanogenic conversion, brewery trub exhibited the highest methane potential (304ml<SUB>CH4</SUB>/g<SUB>COD_substrate</SUB>). Trub also exhibited the highest total volatile fatty acids (tVFA) concentrations in the mixed liquor (ML) during acidogenic conversion (29.7 g<SUB>COD_tVFA</SUB>/kg<SUB>ML</SUB>). Acetic, butyric and caproic acids were the main carboxylates produced by the different substrates. Despite the lower conversion yields, the economic value of the acidogenic product (carboxylate streams) is higher than that of methanogenic conversion (methane) due to the higher value of carboxylates and their potential use in finer applications (e.g. bio-based products) compared to energy production form methane.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Mixed acidogenic fermentation shows lower yields but higher product value than methanogenesis. </LI> <LI> VFA concentrations reported are among the highest in literature for batch acidogenic fermentation. </LI> <LI> Trub is an attractive residue for valorisation due to the potential for caproic acid production. </LI> <LI> Brewery residues have a significant economic potential. </LI> </UL> </P>