Anaerobically treated wastewater contains dissolved digester gas. The methane it contains remains unused as an energy carrier and is released into the atmosphere as a harmful greenhouse gas. 

The DiMeR-process was developed in cooperation with Leibniz Universität Hannover, to efficiently remove gases from the water phase, to utilise them energetically and to make them harmless.

Operating principle

• Suction of the digested sludge from the riser pipe by negative pressure
• Automatic discharge of the digested sludge into a sludge chamber
• Release of dissolved digester gas through reduction of solubilities
• Additional acceleration of outgassing processes through fine bubble stripping (recirculation of captured digester gas)
• Falling film enables release of residual gas bubbles into sludge matrix
• Feeding of the captured gas on the pressure side of the vacuum pump into the existing digester gas collection line of the digesters
• Dosing of precipitant and/or defoaming agent as required

Reduction of greenhouse gas emissions

• Effective recovery of still dissolved methane at the outlet from the digester (overflow into sludge pocket) and return to the gas line
• Methane recovery approx. 90% depending on pressure conditions
• Significant reduction of greenhouse gas emissions in the sludge stack tank and during digested sludge dewatering
  (only approx. 10-15% of the originally dissolved CH4)
• Higher overall efficiency, as installed directly at the digestion tower

• No additional pumps required for sludge transport
• No installations in the reactor head that are susceptible to clogging
• Short pipe runs for the gas line
• Less space required as similar processes
• No additional Ex-protection zone required
  DePrex is installed in an existing Ex-zone
• Significantly increased overall reduction in greenhouse gas emissions from the treatment plant