Kinetics of biogas production in Anaerobic Filters

•High precision online measurement.•Baseload operation with VFA injections into an Anaerobic Filter.•New method determining kinetic parameters & gas yield simultaneously.•kinetic parameters show significant differences between acetic propionic and butyric acid. This study investigates methane production kinetics from individual volatile fatty acids (VFA) in an Upflow Anaerobic Filter (AF). 1gCOD in the form of acetic (HAc), propionic (HPr) or butyric acid (HBu) was injected into the AF while operating at an organic loading rate (OLRCOD) of 3.5gL-1d-1. A new method is introduced to separate gas production of the baseload from the product formation of VFA degradation after the injection. The lag phase, fractional rate of gas production and half-life has been determined for the methane production of the three VFAs. The half-lives were in the order HAc