Biomass hydrolysis inhibition at high hydrogen partial pressure in solid-state anaerobic digestion

Elisabeth Cazier (1) , Eric Trably (1) , Jean-Philippe Steyer (1) , Renaud Escudié (1)

1 LBE - Laboratoire de Biotechnologie de l'Environnement [Narbonne]

In solid-state anaerobic digestion, so-called ss-AD, biogas production is inhibited at high total solids contents. Such inhibition is likely caused by a slow diffusion of dissolved reaction intermediates that locally accumulate. In this study, we investigated the effect of H2 and CO2 partial pressure on ss-AD. Partial pressure of H2 and/or CO2 was artificially fixed, from 0 to 1 557 mbars for H2 and from 0 to 427 mbars for CO2. High partial pressure of H2 showed a significant effect on methanogenesis, while CO2 had no impact. At high P H 2 , the overall substrate degradation decreased with no accumulation of metabolites from acidogenic bacteria, indicating that the hydrolytic activity was specifically impacted. Interestingly, such inhibition did not occur when CO2 was added with H2. This result suggests that CO2 gas transfer is probably a key factor in ss-AD from biomass.

Mots clés: lignocellulosic residues; hydrolysis; hydrogen; gas transfer; dry anaerobic digestion; lignocellulosic residues; lignocellulosic residues; lignocellulosic residues

Domaines: Sciences du Vivant [q-bio]

Elisabeth Cazier, Eric Trably, Jean-Philippe Steyer, Renaud Escudié. Biomass hydrolysis inhibition at high hydrogen partial pressure in solid-state anaerobic digestion. Bioresource Technology, 2015, 190, pp.106-113. ⟨10.1016/j.biortech.2015.04.055⟩. ⟨hal-01149953v2⟩