AD-BES unit


In general, the Bioelectrochemical Systems with Anaerobic DigestionAD-BES enable effective wastewater treatment. An anaerobic digester combined with a bio-electrochemical system (1 m3 volume) produces biomethane with a purity of up to 95% owing to microbial conversion of the organic matter content of wastewater. 

The AD-BES system proposed in the ROBINSON project's case is built by Hysytech.

AD-BES unit

Technical description and Technology Flowchart

AD-BES Technology flowchart

Figure 1 AD-BES Technology flowchart

An anaerobic digester in combination with a bio-electrochemical system (1 m3 volume) produces biomethane – up to a purity of 95% – due to microbial conversion of organic matter content of wastewater. The BES unit is supplied with electricity at a voltage near 1 V, in order to upgrade the AD unit in terms of process kinetics and CH4 content of produced biogas. The technology has several advantages, such as high process efficiency under mild operation conditions, high flexibility regarding power fluctuation and plant size as well as the opportunity for seasonal energy storage in the form of biomethane.

Technology requirements and operating conditions

Some characteristics foreseen for AD-BES units are presented below.

Operational parameters of the AD-BES pilot plant



Biogas production rate

0.12 – 0.22 Nm3/day

Delivery temperature

37 oC

Delivery pressure

0.02 barg

Composition of biogas (range values)

CH4    65 mol% (min value)

H2       0 mol%

H2O    6 mol%

CO2    29 mol%

H2S     500 ppm

VOC    100 ppm

Electrical power need (AC)

3.5 kW

Wastewater demand

100 L/day (min value)

ORL: 0.35 – 0.7 kgCOD/m3/d (min value)

5 oC  - 40 oC

2 – 8 barg

Compressed air

1 Nm3/hr

6 – 8 barg

Flow rate of drain

Min 3 m3/hr

Internet connection (min requirement)

1 Mbps for upload

6 Mbps for download