Effect of volumetric organic loading rate (OLR) on H2 and CH4 production by two-stage anaerobic co-digestion of food waste and brown water

• Published in: Waste management (Elmsford) Vol. 61; pp. 484 - 493
• Main Authors: Paudel, Sachin, Kang, Youngjun, Yoo, Yeong-Seok, Seo, Gyu Tae
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2017
• Subjects: Anaerobic co-digestion; Brown water; Food waste; Hydrogen; Methane; Organic loading; Two-stage system; Food waste; Methane; Anaerobic co-digestion; Two-stage system; Hydrogen; Organic loading; Brown water
• ISSN: 0956-053X; 1879-2456
• DOI: 10.1016/j.wasman.2016.12.013

•The effect of change in OLR by HRT in H2 and CH4 production.•Household generated food waste (FW) and brown water (BW) was used for codigestion.•The highest H2 production and yield was observed in acidogenic reactor at HRT of 8h with OLR of 106gVS/L·d.•The highest CH4 production and yield was observed in methanogenic reactor at HRT of 20days with OLR of 1.24gVS/L·d.•Longer HRT is favorable for higher lactate degradation. Two-stage anaerobic digestion system consisting of two continuously stirred tank reactors (CSTRs) operating at mesophillic conditions (37°C) were studied. The aim of this study is to determine optimum Hydraulic Retention Time (HRT) of the two-stage anaerobic digester system for hydrogen and methane production. This paper also discusses the effect of OLR with change in HRT on the system. Four different HRTs of 48, 24, 12, 8h were monitored for acidogenic reactor, which provided OLR of 17.7, 34.8, 70.8, 106gVS/L·d respectively. Two HRTs of 15days and 20days were studied with OLR of 1.24 and 1.76gVS/L·d respectively in methanogenic reactor. Hydrogen production at higher OLR and shorter HRT seemed favorable 106gVS/L·d (8h) in acidogenic reactor system. In methanogenic reactor system HRT of 20day with OLR of 1.24gVS/L·d was found optimum in terms of methane production and organic removal. The result of this study illustrated the optimum HRT of 8h and 20days in acidogenic stage and methanogenic stage for maximum hydrogen and methane production.