Gas detection3
Respiratory protection4
Technical rescue9
Firefighting4
Safety & environment4
Personal protective equipment2
Bieler+Lang GMC Biogas 08 — biogas analyzer CH₄, CO₂, O₂, H₂S
A fixed biogas analyzer for continuous control of the fermentation process. It measures methane, carbon dioxide, oxygen and hydrogen sulphide in a single cabinet, zeroes its sensors before every measurement and logs the results — for agricultural biogas plants, sewage treatment works and landfill sites.
Why a biogas plant needs an analyzer
Biogas composition changes by the hour — depending on the feedstock, digester temperature and the condition of the bacteria. Without continuous measurement you find out about a problem only when energy output drops or the CHP engine starts to suffer. GMC Biogas 08 measures the gas in defined measuring cycles and warns you earlier: a fall in methane, a rise in oxygen or a spike in hydrogen sulphide shows up straight away on the display and in the plant control system.
Four gases, two measuring methods
Methane (CH₄) and carbon dioxide (CO₂) are measured by a double infrared bench with pressure and temperature compensation. Optical measurement does not wear out like an electrochemical sensor and does not lose sensitivity at concentrations of tens of percent. Oxygen (O₂) shows whether air is getting into the digester or the gas line. Methane, carbon dioxide and oxygen can be measured continuously.
Hydrogen sulphide (H₂S) has its own sample gas channel and a sensor with overload protection. The H₂S measuring interval is set individually — the sensor is not exposed to gas all the time, so it lasts longer where concentrations run into thousands of ppm.
Protecting gas engines
Hydrogen sulphide is the main enemy of CHP engines: it corrodes components and destroys the oil. Continuous H₂S measurement lets you react in time — adjust desulphurisation or cut the engine supply before damage is done. The methane reading, in turn, helps optimise the calorific value of the gas.
A measurement that checks itself
Before every measurement the analyzer automatically zeroes its sensors and checks the pump — if no sample is flowing, it reports it instead of showing a reading of air. The integrated data logger stores 1440 data sets, read out via an RS232 interface, and every measured value is output as a 4–20 mA signal to the plant controller.
Operation is through a clearly laid-out menu in German, English or French. Cabinet ventilation is redundant, and the gas paths have detonation prevention to EN 12874.
Options
- Sample gas cooler with automatic condensate drain — dehumidification by Peltier cooling, sample outlet temperature +5 °C
- Relay module for switching external alarms
- Field bus module for connection to the control system
- Measuring point switch — up to four sampling points
- Connection of up to two gas detectors for area monitoring
We configure it for the specific installation: the number of sampling points, how the data are passed on, and whether the analyzer should also watch the air in the plant room.
Analyzer or gas detection system
GMC Biogas 08 measures the composition of the process gas — how much methane and how many contaminants the biogas contains. That is a different job from protecting people against leaks: for that you use fixed detectors in rooms and alarm controllers such as the GMC 8034 or GMC 8022. A biogas plant usually needs both.
Technical data
| Parameter | Value |
|---|---|
| Type | fixed process gas analyzer in a cabinet |
| Application | biogas, sewage gas, landfill gas |
| Measured gases | CH₄, CO₂, O₂, H₂S |
| CH₄ range | 0–100 vol.% (infrared) |
| CO₂ range | 0–50 vol.% (infrared) |
| O₂ range | 0–25 vol.% |
| H₂S range | 0–5000 ppm, separate sample channel, overload protection |
| Infrared bench | double, with pressure and temperature compensation |
| Operating mode | CH₄, CO₂ and O₂ continuously; H₂S at adjustable intervals |
| Outputs | 4–20 mA for all measured values |
| Data logger | 1440 data sets, read-out via RS232 |
| Self-test | sensor zeroing and pump check before every measurement |
| Safety | detonation prevention to EN 12874, redundant cabinet ventilation |
| Menu language | German, English, French |
| Housing | coated sheet steel cabinet |
| Dimensions | 700 × 500 × 200 mm |
| Weight | approx. 30 kg |
| Protection class | IP20 |
| Made in | Germany |
Service with us
We are an authorised Bieler+Lang trade and service partner — we hold the manufacturer's written authorisation covering commissioning, maintenance and other service work, valid until 31 December 2028. Our technicians were trained in Achern and work with original parts and factory procedures.
In practice that means we commission, calibrate and service what we sell — nothing has to be shipped back to Germany. See our service scope or send equipment in.