Enhancing volatile fatty acids (VFA) production from food waste in a two-phases pilot-scale anaerobic digestion process. Issue 5 (October 2021)

• Record Type: Journal Article
• Authors: Valentino, Francesco; Munarin, Gianluca; Biasiolo, Marco; Cavinato, Cristina; Bolzonella, David; Pavan, Paolo
• Is Part Of: Journal of environmental chemical engineering. Volume 9:Issue 5(2021)
• Publication Date: 2021-10
• Subjects: Anaerobic Digestion (AD) -- Volatile Fatty Acids (VFA) -- Organic fraction of municipal solid waste (OFMSW) -- Acidogenic Fermentation; Chemical engineering -- Environmental aspects -- Periodicals; Environmental engineering -- Periodicals; Chemical engineering -- Environmental aspects; Environmental engineering; Periodicals; 660.0286
• DOI: 10.1016/j.jece.2021.106062
• Languages: English
• ISSNs: 2213-2929

Abstract

Abstract: The bio-based production of added-value products and energy from waste streams while minimizing environmental impacts is a crucial aspect within the circular economy's principles. A two-phases anaerobic digestion process to produce volatile fatty acids (VFA) and biogas production in an energetically feasible manner from the organic fraction of municipal solid waste (OFMSW) has been investigated. Mesophilic temperature (T) coupled to 5.0 days as hydraulic retention time (HRT) gave a VFA-rich stream with an overall concentration of 24.4 ± 0.2 g CODVFA /L, dominated by propionic and valeric acids, and high acidification yield, being VFA close to 90% of the soluble COD. The pH was maintained around 7.0 by the digestate recirculation from the second methanation reactor (HRT of 20 days) where biogas production was quantified under mesophilic and thermophilic T. The assessment of energy balance showed the benefits to carry out the second methanation stage under thermophilic condition, having more income from electricity generation without losing the thermal sustainability of the two-phases process as a whole. Graphical Abstract: ga1 Highlights: Two-phases anaerobic OFMSW fermentation-digestion for bio-refinery development. Mesophilic temperature and high HRT enhanced VFA production and process stability. Neutral pH favours the short chain fatty acid with even number of carbon's atom. Major economic income with methanation stage conducted at thermophilic temperature.