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This pilot unit is equipped with a flanged stainless steel reactor. The reactor bottom is slightly conical. The reactor top, in a shape of a pipe cap, is a gasometer. The reactor is jacketed ; a thermoregulator put hot water into circulation through this jacket ; the heating water temperature is controlled by the temperature of the reactor.


The substrate is fed using a peristaltic pump controlled by an electronic timer ; the sludge is recycled using a peristaltic pump controlled by an electronic timer. The weight of the producing biogas is measured using a mass flow meter. Oxidation-reduction potential and pH are measured on the recycling pipe.

An additional module allows the addition of a semi-solid substrate using a dilution process in a stirred buffer tank.

Supervisor software is used to obtain data acquisitions with a microcomputer. The pilot unit parameters are displayed on a real time flow sheet (pH, rH, temperature and gas mass flow rate) ; this allows to control the pilot unit and simultaneously the data acquisition on the hard disk of the computer.

Time to time, an anti-foaming agent is fed using a pump controlled by an electronic timer.


Teaching objectives

- Purification efficiency determination (treated effluent BOD and COD)

- Ratio between biogas production and purification efficiency

- Influence of the digester temperature and the purification efficiency

- Production and purification optimal condition determination, according to a certain number of parameter variations such as pH, rH, sludge recycling rate and sludge residence time

- Real time operating parameters display on a pilot unit flow sheet

Technical specifications

- AISI 304 stainless steel framework, 40 x 40 square pipes

- Anaerobic reactor, AISI 316 stainless steel, nominal capacity 50 litres, total capacity 75 litres

- Automatic liquid heating system, using circulation of hot water inside the reactor jacket

- Hot water thermoregulator, 95 °C, 6 kW

- Pt100 Ω temperature sensor controller

- Sludge feeding peristaltic pump for, 0-15 l/h flow rate range

- Substrate recycling peristaltic pump, 0-15 l/h flow rate range

- Anti-foaming agent feeding pump controlled by an electronic timer.

- Endress+Hauser pH transmitter - controller, 2 - 12 pH range, 4 - 20 mA analogical output

- Endress+Hauser rH transmitter - controller, -1500 - +1500 mV range, 4 - 20 mA analogical output

- Temperature indicator, 4 - 20 mA analogical output

- Manometer, 0 - 50 mm H2O range

- Mass flow meter, 4 - 20 mA analogical output

- Slow stirrer with a gear motor and a stainless steel propeller, 10 to 50 rpm range, 0.37 kW power

- Electronic variable speed drive. Mechanical seal tightness of the stirrer shaft

- Sludge feeding stainless steel decanter, nominal capacity 2 litres

- Control cabinet IP55 including emergency stop button, transformer, 24 V relays, pump switches and safety devices, transmitters, indicators, controllers, stirrer and heating thermoregulator switches and safety devices

- Stainless steel AISI 304 - 316 and PVC fittings, pipes and valves,

- Technical manual


Option 1 : Data acquisition module

-        A RS 485 - RS232 converter

-        Four 4 - 20 mA   à RS485 converters

-        Data acquisition software

-        Temperature, rH, pH, gas mass flow rate data acquisitions

Option 2 : PC type microcomputer

Option 3 : Additional Module for semi-solid substrates feeding with stirred vessel (A) and level switch


Essential requirements

- Electricity : 380 V three-phase - 50 Hz + earth connection, P = 6,5 kW

- Water supply

- Grounded drain


Dimensions and weight

- 2 300 x 1 000 x 2 020 mm (approximately)

- 250 kg