Comparison of anaerobic digesters performance treating palmitic, stearic and oleic acid: determination of the LCFA kinetic constants using ADM1.

Comparison of anaerobic digesters performance treating palmitic, stearic and oleic acid: determination of the LCFA kinetic constants using ADM1. Bioprocess Biosyst Eng. 2020 Mar 20;: Authors: Eftaxias A, Diamantis V, Michailidis C, Stamatelatou K, Aivasidis A Abstract In this work, the process performance of three parallel anaerobic digesters was evaluated while treating emulsified long-chain fatty acids (LCFA) (i.e., palmitic, stearic and oleic acid) at two different organic loading rates (OLR) (2 and 4 g L-1 day-1). The digester treating palmitic acid achieved a biogas yield of 0.42 ± 0.05 L g-1 COD with a digester effluent COD of 2.3 ± 0.4 g L-1 and VFA concentrations below 250 mg L-1. Stearic acid showed lower biogas yield values (0.34 ± 0.05 L g-1 COD) with low effluent COD (2.5 ± 0.4 g L-1) and VFA concentrations (< 350 mg L-1). On the contrary, anaerobic digestion of oleic acid was accompanied with increased effluent COD (4.5 ± 0.7 g L-1) and VFA concentrations (2.7 ± 1.5 g L-1). As such, COD removal efficiency remained at 89 ± 1% compared to 95 ± 1% for the digesters treating palmitic and stearic acid. During continuous digester operation, there was a decrease in VFA concentrations (around 1-2 g L-1), combined with increasing biogas yield values up to 0.51 ± 0.04 L g-1 COD, possibly due to biomass adaptation to oleic acid. Digester foaming was recorded when the accumul...
Source: Bioprocess and Biosystems Engineering - Category: Biomedical Engineering Authors: Tags: Bioprocess Biosyst Eng Source Type: research