ELOVAC® is a compact, skid-mounted vacuum degassing technology for digested sludge. It extracts residual biogas from digested sludge for beneficial utlisation, while preventing diffuse methane emissions.

Unique Benefits

Improve digester capacity

Vacuum degassing can also improve the sludge digestion process of the entire wastewater treatment plant. We are currently investigating how vacuum degassing can improve digester performance – for example, sludge density, and thus increase digester capacity while avoiding foaming issues.

How can ELOVAC® improve digester capacity?

- Faster release of the gas from the sludge floccs
- Higher density of the sludge
- Higher amount of biomass in the digester
- Higher sludge age (HRT) in the digester
- Better mass transfer
- Avoid dosing high amounts of defoamer
- Better mixing of the digester


Improve the carbon footprint of the treatment plant

Vacuum degassing on its own can have a significant impact on the carbon footprint of the treatment plant.

Only with the implementation of ELOVAC® the following results were achieved:

- 3 kg avoided CO₂-equivalent emissions per cubic metre of digested sludge. In absolute numbers, this means (for a 100.000 PE treatment plant) the  avoidance of 410 kg CO₂-equivalent emissions or approx. 3,200 CO₂-neutral car-kilometres per day (based on threshold fleet consumption car CO₂emission 130 g CO₂/km.

Additional 0.63 kWHₑₗ per cubic metre sludge from the withdrawn biogas make the operation of ELOVAC® energy positive

Improve dewaterability

See how it works

  1. Sludge is fed continuously to the degassing reactor tank via a control valve or a pump
  2. In the degassing tank, a vacuum pump withdraws the gas present in dissolved form and as bubbles from the digested sludge.
    The pressure and the amount of sludge in the degassing tank are controlled to predefined values.
  3. The vacuumed gas enables an energy-positive operation by capturing additional biogas, while reducing greenhouse gas emissions.
  4. The degassed digested sludge is continuously discharged from the degassing tank to the downstream sludge treatment step, typically dewatering.

ELOVAC® footprint in relation to the digester

ELOVAC® - scalable fit for your requirements


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Contact us

Maria Dittmann
Jahnstraße 36
88214 Ravensburg
Tel. +49 751 359785-14