During the generation of biogas, various contaminant gases occur beside the desired methane. Hydrogen sulfide (H2S) and volatile siloxanes (VMS) are two main contaminants causing severe damage to facility parts and attached cogeneration units. Different filtering techniques are established, but operated in inefficient overdosing mode because current detection systems are measuring discontinuously or having no detection unit for contaminants at all. Scope of the thesis is the development of a sensor concept, which is able to continuously and selectively measure contaminant gases for dynamic control system to improve filtering techniques and prevent frequent maintenance or failure. For the mentioned gases possible approaches for the detection of H2S, being a reducing gas, are for example the resistive read-out of polymer ion-sensitive layers or copper oxide/tin oxide hetero junctions. Molecules of the VMS family are comparably unreactive. This requires research on specifically adsorbing layers and mass- or surface sensitive detection principles.
