The COMBIMASS® GA-s hybrid premium air monitoring analyzer station consists of a ventilated cabinet for the cyclic analysis of the air of 1 up to 4 fermenters for indoor installation with an integrated display and flexible measuring program. The gas modules have an integrated maintenance diagnosis whereby the wear is signaled by the traffic light colours.
Transmission of data and alarms is possible via various bus systems. Additionally, the warning lamp rounds off the station for a simple and safe operation.
- Plastic wall cabinet 600x600x200 with PLC and 4.3″ graphic display for controlling the pumps and valves for installation in a safe room, 24 VDC (optional: outdoor installation / operation in EX zone 2)
- Analysis of the supply and exhaust air of a membrane foil roof (option: expandable up to 4 membrane foil roofs)
- Connections on the station prepared for plastic hoses (option: stainless-steel tubes)
- Data transmission via analog signals 4-20 mA, 1 common alarm (option: pre-alarm and main alarm) or various standard bus systems (option: warning lamp)
- Easy replacement of typical wearing parts such as filters, valves, pumps and gas modules
- Optical analysis of methane with a measuring range of 0-2,000 ppm through the difference between AIR- IN and AIR- OUT, with integrated maintenance diagnosis (option: extension with a H2S gas module with required measuring range 0-10 ppm / …/ 0-10,000 ppm for exhaust air measurements)
- Manual or autocalibration function
- Patent pending for the process
Fermenters in agricultural biogas plants are often covered with single or double-wall membrane systems. The latter are permanently maintained with air to prevent biogas losses and emissions of biogas into the atmosphere. Over the course of years, the membrane foils are subjected to changes. This can lead to increased emissions or in the worst-case lead to rupturing of the membrane.
TRAS 120 (Safety Requirements for Biogas Plants) states: “The tightness of membrane systems must be monitored. For this purpose, they shall be operated with an additional outer covering of the gas membrane, which allows continuous monitoring of the gap. Membrane systems that do not meet this requirement shall be replaced by a monitorable double walled system at latest by the end of their service life or after irreparable damage to the membrane”. Furthermore, the paper defines a maximum permissible membrane permeation.
Therefore long-term monitoring is considerably important. The service life can be extended by permanently monitoring the membrane roofs. This not only reduces investment costs, but also waste products and the costs for the disposal of plastic membranes.
The new GA-s hybrid air monitoring system is based on the long standing proven modular concept of the hybrid series. Solely the gas modules are adapted to the requirements of air analysis.
The specific challenge here is the small measuring range of only a few ppm for methane compared to biogas. The standard measuring systems available on the market today for biogas in the vol.% range are not suitable because they cannot resolve the small concentrations with sufficient accuracy. The optical measuring cell specially developed for this application and tested under real conditions can also measure methane concentrations of 50 ppm very accurately. In addition, a differential measurement of inlet air versus outlet air is carried out because often there are already low methane concentrations in the air in the vicinity of the fermenter (see weekly screenshot). This enables an exact representation of the actual permeation without distortion by external influences – a patent application has already been filed for the process.
The analyzer station can also be used for exhaust air applications by using a H2S measuring cell with a customized measuring range.
- Air from double-walled membrane gas storage tank
- Exhaust air containing methane and hydrogen sulphide from buildings and processes