The use of two-phase reactors, whic

The use of two-phase reactors, which can improve the processing capacity due to the separation of the steps and through the use of different pretreatments, which can improve biogas production, methane concentration and is also beneficial for anaerobic digestion plants. In this study, we tested a CSTR with the addition of an incubation reactor (where a nutrient mix is added) on both a lab and industrial scale, in which the substrate from the acidogenic fermenter reactswiththenutrientsandthenreturnsintothesamereactor. Thissystemallowstoavoiddisrupting the syntrophic relationship between acid-producing bacteria and methanogens and so balancing the production of volatile fatty acids and of acetic acid. The system proposed is an economic system to adopt for both one-stage and two-stage anaerobic digestion plants, given the reduced volume and the simplicity of the additional reactor. As far as the authors are concerned, the coupling of incubator systems to anaerobic digestion plants is a new aspect which is worthy of investigation.