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New developed mobile measuring system for methane loss at biogas upgrading facilities successfully launched


For the release quantity of methane through the exhaust flow of a biogas upgrading facility a mobile measuring system was successfully launched. In place stored measuring data of the flow and methane concentration measurement at the exhaust flow is sent via remote data transmission to PTB. With that collected data and the data of the product gas, which is measured by calibrated meters, a balance of the methane loss is made. 

Due to the energy turnaround the importance of regenerative energies like biogas are growing. This applies especially to injection of upgraded biogas. The number of biogas upgrading facilities rose from 3 facilities in 2006 up to 120 facilities in 2012. In this topic the PTB takes place in the joint research project „monitoring of the biogas upgrading process“ (MONA), which consists of six partners.

Within the scope of the joint research the task of the PTB is the qualitative and quantitative detection of the methane content in the exhaust flow of a biogas upgrading facility. For that purpose a mobile measuring system was designed, built and launched in cooperation with RMG Butzbach (Figure 1). This measuring system is realized as a custom made trailer for outdoor mission. The trailer consists of two separated rooms: one for the measuring equipment, which includes an operator’s position, storage for external components, and another room for gas stock, which is needed for the gas analysis.

Figure 1: Exterior and interior of the mobile measuring system
Left picture: side view of the measuring system: utility lines, heated sample gas line and additional equipment
Right picture: interior view from the rear of the trailer: supply lines for the gas sample, control cabinet including measuring technology, operator’s position in the back.

Because the facilities don’t give the opportunity to install a commercial meter, a custom measuring sleeve was designed in cooperation with SICK Dresden. With this custom meter only two holes in the pipe are needed to measure. This technique in connection with ultrasonic is in use for the first time. For the determination of the methane concentration a flame ionization detector is installed on the trailer. The measuring devices are calibrated in the PTB before field operation.

The mobile measuring system works for about two weeks at the facility, in doing so the system is subjected to a functional check before field operation. Additionally an exhaust gas sample is taken for analysis in a PTB laboratory. The remote data transmission allows operation surveillance.

The observed data are correlated with the respective facility status (normal operation, pressure, temperature, in addiction to upgrading technique), statistically evaluated and the methane loss is determined.

Up to now measuring campaigns were successfully performed at two facilities. Another eight campaigns are in plan.

Contact person:

Hans-Benjamin Böckler, Dept. 1.4, WG 1.42, e-mail: hans-benjamin.boeckler@ptb.de