From day 116 to 281 nutrient limitation trials were conducted, the objective was to find whether the trickling or supply method is the limiting factor or the concentration level of the nutrients in the media sump are the limiting factor. To stabilize the reactor the gas feed flowrate to the reactor was reduced and GRT was increased from 25.7 min to 43.2 min. This temporality improved the H 2 conversion but overall, the C H 2 kept increasing at the outlet of the reactor, as shown in Figures and.