Raw biogas is good, purified biogas is even better…

Gas purification means that after different kind of cleaning procedures, the gas is prepared for an energetic or material use. Raw biogas is produced in biogas plants and contains different kind of gases as well as water and foam- or contamination particles. The same applies to sewage gas and landfill gas.

Ennox supplies the required equipment for separation of the dust, foam particles and condensation water, such as gravel filter, ceramic fine filter, condensate pot, sediment pot and gas chill dryer. For removing chemical contamination like H2S and siloxane a biological desulphurisation and an active carbon filter can be used.


Active carbon filter carboNOX

Biogas can contain large quantities of poisonous hydrogen sulphide depending upon the fermentation process and which input materials are used. This gas can cause permanent damage to gas engines or other consumers of the biogas.

The majority of the hydrogen sulphide gas can be effectively removed by using an ennox active carbon filter ACF.

In addition, the active carbon filter can be used for the removal of damaging siloxane from the biogas, furthermore for the neutralization of unpleasant odours in outgoing air and tanks.

Ceramic fine filter CFP

Gas from bio or sewage processing systems are often contaminated with water vapour or very sparsely distributed small particulate matter, which, when used for example in CHP units can cause operating problems or even damage. For the fine cleaning of the gases before utilization an ennox ceramic fine filter is used.

In the ennox ceramic fine filter the fine particles contained in the gas are captured by a special fire-clay filter (Pantel). Condensate collects in the form of a moisture layer on the surface of the material and drips into the collector below.

An automatic discharge system with level indication can be installed in the base of the digester upon request.

Condensate accumulator COA

Condensation from saturated biogas collects at the lowest points in the pipework, in bends etc. This can negatively influence the effective operation of biogas systems.

ennox condensate accumulator is installed at the lowest point in the pipework. The condensate gathers in the container where it can be discharged through a manual tap and/or an automatic siphon.

As an option ennox will supply a level indicator or an automatic discharger.

Condensate pot COP

Bio or sewage gas is saturated with water vapour. Condensation can occur within the pipework systems of digester systems as a result of fluctuating temperatures. The ennox condensate pot allows for the collection and controlled discharge of any condensation water accumulations.

The gas flows through the condensate pot where it is channeled within the pot through a separation chamber. The reduction in gas flow velocity and the influence of temperature fluctuations cause the water vapour in the gas to condense and collect at the bottom of the pot.

The collected condensate can be discharged from the point of collection either with a siphon or an automatic discharger.

Gas chill dryer GCD

Biogas, sewage gas and landfill gas contains not only water vapour, but also a whole host of additional impurities such as hydrogen sulphide, NH3 and siloxane, which, when processed in the utilization system can not only lead to a reduction in efficiency, but also result in damage to the system.

The dehumidification of the gas before processing is a basic preliminary requirement in order to permit an efficient usage of the biogas and an investment in the sustainability of the utilization system.

With the ennox gas chill dryer the gas to be processed is passed through a heat exchanger where the cooled gas can expel any moisture which drips and is collected as condensate.
According to the technical requirements of the installation a post-warming or an economical and ecological energy recovery system can be implemented into the system.

Gravel filter GFR

The gas removed from biogas digestion or fermentation units can be heavily contaminated with foam particles, various particulate matter and water vapour. A pre-filtration of the gas (often adequate enough) can be achieved with the use of an ennox gravel filter.

The gas flows through the ennox gravel filter layer where large particulate matter and water vapour is left behind. The water collects at the bottom of the filter where it can be drained with a siphon assembly.

Following heavy contamination of the gravel filter the spraying unit can be used for rinsing, avoiding the need for opening the digester unit. As an option a gravel removal opening can be installed.

Sediment trap SET

Fine sediment and foam particles in the saturated biogas originating directly from the digestion can make it´s way into the pipework system. In order to eliminate sediment accumulation in the pipework an ennox sediment trap can be used.

The trap is installed after the reactor directly in the pipework. With a special nozzle at the trap inlet the saturated and contaminated gas is set into a spiral motion. The particulate matter separates from the gas on the side walls and passed into the collection point with the extracted water vapour.

Discharge is carried out with a siphon. Additionally a spray and control connection can also be installed.