title: Effect of substrate and cation requirement on anaerobic volatile fatty acid conversion rates at elevated biogas pressure.
abstract: This work studied the anaerobic conversion of neutralized volatile fatty acids (VFA) into biogas under Autogenerative High Pressure Digestion (AHPD) conditions. The effects of the operating conditions on the biogas quality, and the substrate utilisation rates were evaluated using 3 AHPD reactors (0.6 L); feeding a concentration of acetate and VFA (1-10 g COD/L) corresponding to an expected pressure increase of 1-20 bar. The biogas composition improved with pressure up to 4.5 bar (>93% CH4), and stabilized at 10 and 20 bar. Both, acetotrophic and hydrogenotrophic methanogenic activity was observed. Substrate utilisation rates of 0.2, 0.1 and 0.1 g CODCH4/g VSS/d for acetate, propionate and butyrate were found to decrease by up to 50% with increasing final pressure. Most likely increased Na(+)-requirement to achieve CO2 sequestration at higher pressure rather than end-product inhibition was responsible.
authors.affiliation: Sub-Department of Environmental Technology, Wageningen University, Bornse Weilanden 9, 6708 WG Wageningen, The Netherlands. Electronic address: ralph.lindeboom@wur.nl.
authors.forename: Ralph E F
authors.initials: RE
authors.lastname: Lindeboom
authors.forename: Ivet
authors.initials: I
authors.lastname: Ferrer
authors.forename: Jan
authors.initials: J
authors.lastname: Weijma
authors.forename: Jules B
authors.initials: JB
authors.lastname: van Lier
mesh_terms: D000085:Acetates / Q000378:metabolism; D000693:Anaerobiosis / Q000187:drug effects; D061249:Batch Cell Culture Techniques; D056804:Biofuels; D002087:Butyrates / Q000378:metabolism; D002412:Cations / Q000494:pharmacology*; D005232:Fatty Acids, Volatile / Q000378:metabolism*; D008697:Methane / Q000378:metabolism; D011188:Potassium / Q000032:analysis; D011312:Pressure; D011422:Propionates / Q000378:metabolism; D012964:Sodium / Q000032:analysis; D013379:Substrate Specificity / Q000187:drug effects
chemical_list: D000085:Acetates; D056804:Biofuels; D002087:Butyrates; D002412:Cations; D005232:Fatty Acids, Volatile; D011422:Propionates; D012964:Sodium; D008697:Methane; D011188:Potassium
keywords: Anaerobic digestion; Biogas upgrading; Carbon dioxide; Methane; Pressure