title: Substrate milling pretreatment as a key parameter for Solid-State Anaerobic Digestion optimization.
abstract: The effect of milling pretreatment on performances of Solid-State Anaerobic Digestion (SS-AD) of raw lignocellulosic residue is still controverted. Three batch reactors treating different straw particle sizes (milled 0.25 mm, 1 mm and 10 mm) were followed during 62 days (6 sampling dates). Although a fine milling improves substrate accessibility and conversion rate (up to 30% compared to coarse milling), it also increases the risk of media acidification because of rapid and high acids production during fermentation of the substrate soluble fraction. Meanwhile, a gradual adaptation of microbial communities, were observed according to both reaction progress and methanogenic performances. The study concluded that particle size reduction affected strongly the performances of the reaction due to an increase of substrate bioaccessibility. An optimization of SS-AD processes thanks to particle size reduction could therefore be applied at farm or industrial scale only if a specific management of the soluble compounds is established.
authors.affiliation: INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France.
authors.forename: J-C
authors.initials: JC
authors.lastname: Motte
authors.affiliation: INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France.
authors.forename: R
authors.initials: R
authors.lastname: Escudié
authors.affiliation: INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France.
authors.forename: J
authors.initials: J
authors.lastname: Hamelin
authors.affiliation: INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France.
authors.forename: J-P
authors.initials: JP
authors.lastname: Steyer
authors.affiliation: INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France.
authors.forename: N
authors.initials: N
authors.lastname: Bernet
authors.affiliation: INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France.
authors.forename: J-P
authors.initials: JP
authors.lastname: Delgenes
authors.affiliation: INRA, UR0050, Laboratoire de Biotechnologie de l'Environnement, Avenue des Etangs, F-11100 Narbonne, France. Electronic address: claire.dumas@supagro.inra.fr.
authors.forename: C
authors.initials: C
authors.lastname: Dumas
mesh_terms: D000693:Anaerobiosis
keywords: Degradation dynamics; Dry anaerobic digestion; Particle size; Substrate soluble compounds; Wheat straw