Carbon: Science and Technology (Apr 2015)
Monitoring of biogas plants - experiences in laboratory and full scale
Abstract
To control and regulate the biogas process there are online process parameters and offline process parameters, which basically don’t differ between pilot biogas plants and industrial biogas plants. Generally, temperature, pH-value, volume flow rate and sometimes redox potential are measured online. An online-measurement of the dissolved volatile fatty acids and an online-detection of dissolved hydrogen both directly in the liquid phase as well as near-infrared spectroscopy are under development. FOS/TAC-analysis is the most common offline-analysis of the biogas process and normally it is carried out by the plant operator directly at the biogas plant. For example dry matter, organic dry matter, nitrogen and fatty acids are other analyses, which are carried out but by a laboratory. Microbiological analyses of biogas plants are very expensive and time-consuming and are therefore in Germany very rare. Microbiological analyses are mainly for research purposes. For example the Fluorescence in situ Hybridiation (FISH) is used for characterization of the populations. Electric-optical measurement should be established as a new method to investigate the vitality of the methane producing microorganisms. In a cooperation project, which is promoted by the German ministry for technology, between IASP and Chair of Bioprocess Engineering at TU Berlin, this method is proper investigated using a device from the firm EloSystems. The microorganisms are brought in an electrical field of different frequencies. In this field the microorganisms direct themselves differently according to their physiological state. At the end of this project an early detection of process disturbance will be possible with the help of this method. In this presentation the result of the first tests are presented.
