There are several different reactor configurations to improve the efficiency of biogas plants. The comparison and assessment of these are usually based on experimental observations. There, the substrate and the microbial community are in general not well characterized and differ in the different analyses in literature. That is why the results are not direct comparable or even lead to contradicting conclusions. In the present analysis, the different reactor configurations are compared on a common basis with defined conditions and composition by using simulations of a well established mathematical model. The configurations are grouped with respect to their working principles, namely spatial and temporal distribution as well as increase of the solid retention time. It was found that reactors with temporal as well as spatial distribution have a higher methane yield than a continuous stirred tank reactor. But the maximal possible space-Lime yield is lower. Reactors with an increased solid retention time can be operated at space-Lime yields of another order of magnitude, which leads to smaller reactors for a desired methane production rate. (C) 2013 Elsevier Ltd. All rights reserved.