WBG-type biogas dryer

MTA WBG-type biogas dryers cover a wide range of requirements from 50 to 10,000 Nm³/h under negative or positive pressure, generate very low pressure drop and address the following main applications:

• Biogas from wastewater treatment plants.
• Biogas from non-hazardous waste landfill sites.
• Biogas from mesophilic or thermophilic digesters for local authorities, industrial sites or agricultural plants.
• Mine gas (firedamp).
• Biomethane for injection into the natural gas grid.

Main advantages of the MTA WBG-type biogas dryer

• All-stainless-steel heat exchangers with removable heads allowing the tube bundle to be cleaned, so the original pressure drop is maintained over time.
• An all-stainless-steel coalescing demister separator, removable and washable, maintaining the original pressure drop over time. It is mounted directly on the dryer exchanger and delivers separation efficiency close to 100% across a wide flow range.
• Very low pressure drop thanks to compact, fully smooth tube bundles.
• A dew point held constant despite sudden variations in the biogas flow to be treated, thanks to a high thermal mass. This thermal mass also limits the starts and stops of the refrigeration unit, extending the life of the refrigeration components.
• Energy consumption proportional to the thermal load to be handled: as biogas varies over time in flow, pressure, humidity and temperature, the WBG-type dryer adapts immediately to the new operating conditions.
• MTA WBG-type biogas dryers accept a high inlet temperature for the gas to be treated. On certain models, biogas with an inlet temperature above 160 °C can be handled.
• A simple, proven conventional design using off-the-shelf components, limiting and simplifying maintenance operations.
• The WBG-type biogas dryer is designed and protected for aggressive gas atmospheres.
• The dryer exchanger and the separator have thermal insulation acting as a vapour barrier, protected from sun exposure by a UV-resistant coating.

Main options for the MTA WBG-type biogas dryer

• Frame-mounted assembly and hydraulic connection between the exchanger/separator section and the refrigeration section, the whole meeting ATEX Zone II requirements.
• Stainless steel casing for the refrigeration unit.
• Variable speed drive for the axial fans.
• 460 V/3/60 Hz power supply with UL certificates.
• Hydraulic connections with an interface compliant with ASME VIII.

The MTA WBG-type biogas dryer, using refrigeration with dynamic thermal mass, consists mainly of:

• a dryer exchanger, condensing the water vapour contained in the biogas on the cold-wall principle. The liquid water thus formed is separated from the gas by a particularly effective coalescing demister separator. Condensates are drained by gravity.
• a refrigeration unit matched to the thermal balance of the dryer exchanger, fitted with a hydraulic module.

It offers a high thermal mass that copes with sudden variations in the thermal load to be handled (biogas). The refrigeration unit is engaged in proportion to the thermal load to be handled, thereby limiting electricity consumption.


The MTA WBG-type biogas dryer with dynamic thermal mass refrigeration is available in two process configurations.

Biogas dryer installed downstream of a digester with mesophilic digestion, or upstream of a booster

Biogas dryer installed downstream of a digester with thermophilic digestion, or downstream of a booster