Biogas composition analysis systems are a critical component of industries like wastewater treatment, waste management, biomass fuel production or agriculture. By monitoring specific components such as methane, hydrogen sulfide, carbon dioxide or oxygen, they help guarantee the quality and safety of biogas and biomethane while ensuring compliance with environmental regulations.
The Fuji Electric ZPAF biogas analyser continuously and simultaneously measures the 4 main components of biogas:
The Fuji Electric ZPAF Biogas Analyser measures the biogas components with the ranges shown in the following table:
|1st range||2nd range||Principle|
|CH4 METHANE||0…20% vol||0…100% vol||Single-beam NDIR|
|CO2 CARBON DIOXIDE||0…20% vol||0…100% vol|
|H2S HYDROGEN SULFIDE||0 ... 500 ppm||O ... 2000 ppm or 0 ... 5000 ppm||Constant-potential electrolytic|
|O2 OXYGEN||O ... 10% vol||0 ... 25% vol||Galvanic fuel cell|
The Fuji Electric ZPAF biogas analyser has the following technical specifications and metrological performances:
|Repeatability||≤ ± 0,5 % FS (H2S : < ± 2,0 % FS)|
|Linearity||≤ ± 1,0 % FS (H2S : < ± 2,0 % FS)|
|Zero drift||≤ ± 2 % FS per week|
|Span drift||≤ ± 2 % FS per week|
(H2S : ≤ ± 2,5 % FS per week or ≤ ± 5 % FS per week)
|Response time (for 90%)||10-30 s (H2S: 180 s)|
|Output analogue||4-20 mA DC or 0-1 V DC|
|Contact input||12-24 V DC, < 9 points|
|Contact output||SPDT, < 15 points|
|Communication (option)||RS-485 (Modbus)|
|Power supply voltage||100-240 V AC, 50/60 Hz|
|Dimensions and weight||483 (L) x 133 (H) x 382 (P) mm, approx. 9 kg|
To measure the composition of the biogas, a biogas analyser uses different analytical methods depending on the component to be analysed.
CO2 and CH4 are measured using non-dispersive infrared (NDIR) absorption technology.
The measurement principle of an infrared gas analyser (NDIR) is described on the Fuji Electric multi-gas infrared analyser page.
O2 is measured by the electrochemical method.
The measurement principle of the electrochemical O2 cell is as follows:
Two electrodes are enclosed in the cell filled with electrolyte. When biogas enters the cell, a chemical reaction occurs, generating a flow of electrons and thus an electric current, proportional to the amount of oxygen present in the biogas.
H2S is measured by the electrolytic method at constant potential.
Two chemical reactions are required for this method.
The H2S to be measured reacts with the moisture (H2O) present in the cell at the working electrode.
Reaction at the working electrode
H2S + 4H2O --> H2SO4 + 8H+ + 8e-
In the same time, at the auxiliary electrode, a second reaction takes place between the oxygen (O2) also present and the hydrogen ions (H+) generated by the first reaction.
Reaction at the auxiliary electrode
O2 + 4H+ + 4E- --> 2H20
The flow of electrons varies in proportion to the amount of H2S present in the cell.
For both reactions to take place, it is therefore necessary that the cell contains not only the H2S to be measured but also a minimum of oxygen and moisture.
The Fuji Electric ZPAF analyser measures H2S continuously because it is provided with an automatic regeneration system for the H2S measuring cell.
Since the H2S measuring cell uses the electrolytic constant potential method, it is imperative to include oxygen and moisture in the gas to be analysed. With this automatic regeneration system, ambient air is supplied to the transmitter at regular intervals to allow the analysis of the biogas, which is often oxygen-free and dried out before analysis.
Fuji Electric helps preserve our environment and save natural energy.
Accurate continuous measurement of biogas composition. Up to 4 components including H₂S measured continuously and simultaneously.
Biogas production and processing sites are subject to environmental constraints in terms of corrosivity and toxicity (presence of H2S), explosivity (presence of CH4), but also potentially high thermal stress and dust.
The Fuji Electric ZPSB biogas analysis system has been designed to measure the composition of biogas at industrial sites such as non-hazardous waste landfills (NHWL), sewage treatment plants and anaerobic digesters and fermenters.
These applications include:
Proven excellent performance of Fuji Electric gas analysers
Simultaneous & continuous measurement of CH4 , CO2 , O2 and H2S
Flexible solutions that fit the specificities of the site
Flexible solutions that adapt to the specifics of the site
See all the benefits of the Fuji Electric ZPSB biogas analysis system.
The ZPSB biogas analysis system incorporates the ZPAF biogas analyser. It has the following technical features:
|Measured components||1 to 4 measured components: CH4 / CO2 / O2 / H2S|
|Technology||CH4 / CO2||NDIR|
|O2||Galvanic cell sensor|
|H2S||Constant potential electrolytic sensor|
|Measurement Ranges||CH4 / CO2||0 - 20 %vol||0- 100 %vol|
|O2||0 - 10 %vol||0 - 25 %vol|
|H2S||0 - 500 ppm||0 - 2000 ppm or 0 - 5000 ppm|
|Power supply||100 to 240 V AC 50/60 Hz|
|Display||Backlit LCD display (Standard)|
Fuji touch panel interface (Multipoint Sampling Option)
|Displayed information||Standard: Measured components, concentrations, alarms, configuration menus, calibrations and advanced diagnostics|
Option: Advanced functions with multipoint sampling (see multipoint system option)
|Dimensions||Standard Single Point Wall mounted cabinet: 750(W) x 750(H) x 500 (D)|
|Weight||Standard Single Point Wall mounted cabinet: 50 kg|
|Structure||Standard Single Point Wall mounted cabinet: consolidated polyester cabinet for outdoor use|
|Response time||CH4 / CO2 / O2||≤ 30 sec|
|H2S (0 - 2000 ppm)||≤ 180 Sec|
|H2S (0 - 5000 ppm)||≤ 300 sec|
|Repeatability||CH4 / CO2 / O2||≤ ± 0,5% PE|
|H2S||≤ ± 2% PE|
|Linearity||CH4 / CO2 / O2||≤ ± 1% PE|
|H2S||≤ ± 2% PE|
|Analog Outputs||4 - 20 mA (one analogue output per component)|
|Communication||Standard: Concentration measurements and status signals (alarms, calibrations) RS485 Modbus RTU|
Option: Ethernet Modbus IP (multipoint sampling)
|Digital Outputs||Standard: Dry contact general alarm including analyser fault and sampling system fault|
General Alarm light indicator on cabinet front door
|Ambient temperature||-5 °C to +40 °C|
|Ambient humidity||90% RH max|
|Sampling||PTFE or Stainless Steel tube|
4 to 6 mm internal diameter
Option: ATEX heated line
|Biogas Pressure||Sampling pump for ambient pressure or low-pressure biogas (< 100 mbar g)|
High-pressure biogas: system with pressure reducer
|Single point system||Continuous measurement of a single stream: sampling, dryer, filtration, bypass, flow adjustment, H2S absorption (option)|
|Multipoint system (Optional)||Additional advanced features:|
Fuji Touchscreen interface and PLC
Configuration of the number of components measured (max. 4)
Configuration of the number of biogas streams analyzed (max. 6)
Configuration of stream switching sequence, measurement times, purge times
Automatic or manual switching setting
Display of the 4 (max) measured components concentrations of the 6 (max) analyzed streams
Display of sampling and analyser alarms
Modbus output of the measurement, status and alarms
Analog outputs and digital outputs (option)