Increasing the efficency of Biogas plants
In times of ever rising prices for oil Biogas and other renewable enegies are standing more and more in the focus of economical interests. The amount of produced gas and it´s quality is strongly dependent on the composition of biomass and it´s DS(dry substance)-content. Because the charge of fermenters in many times is influenced by strong variations, the control of the plant for optimization of gas production becomes high meaning.
One task in this context, which until now hardly could be solved in an economical way, is the monitoring of DS content.
Hf sensor newly offers for this a microwave based measuring system, which was designed especially for use in biogas plants.
The intensive cofermentation of different materials leads to new requirements for fermentation and measuring technology. The bacteria involved in the biogas production and generating acetic acid and methan are standing in a symbiotical relationship concerning their opposite food demands. To keep this equilibrium working, which is highly depending on the composition of charged biomass, is an important task for the control unit of the plant.
Therefore continous monitoring the composition of biomass and especially of DS content is important for achieving optimal conditions for bacteria. Until now this was possible only by complicated and time consuming offline methods.
DS content measurement becomes much easier with the new microwave based DS sensor series MWTS PP. These sensors are monitoring the DS content online reliably and practically free of maintenance in fermenters and tubes.
MWTS PP is available in some predefined configurations for different variants of mounting. The basis are always intelligent microwave sensors with integrated micro controller. Measurements are possible in different configurations without contacting media. The measurement can be done in a DS range between 0 and < 20% DS.
Dry Substance Measurement in reference plants - Biogas plant Breitenworbis
The picture shows a test installation in the biogas plant Breitenworbis/Thuriniga. The DS sensor configuration MWTS PP guard was mounted in an guiding tube with 70 mm diameter. It rises about 200 mm in the fermenter and is covered at it´s end with a 5 mm plexiglass cover. This leads to good coupling of microwaves in the material even if there is no direct contact in the sample.
Sensor signals are guided via 20 m cable to a container with the control unit of the biogas plant. The signals are transferred by RS485, which would allow a theoretical line length of 1000 m. In the container the signals can be processed either by a PLC or via additional interfaces in a PC.