AGAMA BiogasPro-3 Light Top

The AGAMA BiogasPro-3 Light Top is the top section of our latest digester, and was launched in 2013.  It is best suited to rural projects where small households have a digester is built in the ground with local labour, and the smart technology placed on top.

The AGAMA BiogasPro3 Light Top:

  • mixes the contents for increased gas generation efficiency
  • naturally decomposes biodegradable materials without the additional any chemicals
  • stores the biogas that is generated by this natural decomposition
  • generates an internal pressure which allows the biogas to be piped directly to the point of use


The digester mixing, gas storage and pressurisation are all achieved without any mechanical input at all i.e. no pumps or motors of any kind.
It weights 75 kg, and can store up to 800 litres of biogas.
The AGAMA BiogasPro3 Light Top can be shipped completely assembled for one unit or in 4 pieces to reduce the transport costs for multiple orders.

Mechanical specifications
• Gas store volume 600 litres
• Expansion volume 600 litres
• Max gas pressure 5.8 kPa

Dimensions – BiogasPro-3 Light Top
• Diameter (max) – 2100mm
• Height – 1400 mm
• Weight – 75 kg
• Wall thickness 4mm, stiffened in areas to 6mm
• Sewer inlet depth – 600 mm max

Environmental specifications
Operating temperature: +10°C to +40°C
COD reduction 50% – 98% ( feedstock and loading conditions dependent)

Loading specifications
• Feeding rates are feedstock and temperature dependent. A maximum of 500 litres of water can be added daily
• Expect a difference in gas production between winter and summer months. Loading should be reduced in winter to account for the slower biological activity

Temp (deg C)    Max loading (kg/day)    Min water (litres/day)    Gas production @ min water (m3/day)
Food waste

15    15    25    1.72
17.5    15    25    1.97
20    15    25    2.23
25    20    35    3.51


15    10    30    1.41
17.5    10    30    1.61
20    10    30    1.82
25    15    40    3.20


15    20    20    0.61
17.5    20    20    0.70
20    25    25    0.97
25    30    30    1.41

• The recommended minimum ratio of fresh feedstock to water is 1:2

Energy specifications
• Biogas production is proportional to the amount of feedstock and operating temperature
• Biogas contains approximately 60% methane (CH4), 39% carbon dioxide (CO2) and 1% hydrogen sulphide (H2S)
• Each cubic metre of biogas has the heating capacity of
approximately 0.43 kg LPG
• The nominal daily energy output is equivalent to approximately 0.5 kg LPG

 Installation of the gas tight top.

1. Prepare the wall of the tank with the protruding threaded rods in the correct positions, then place a mortar layer on the top of the wall.


2. Lower the LightTop on to the wall/fresh mortar, and under its own weight press the flange into the mortar, and leave it overnight.


3. Raise the LightTop slightly off the mortar the following day, using a car jack from below.  Apply a thick layer of Bituseal (sealing compound)  into the groove made in the mortar by the flange of the LightTop


4. Allow the LightTop  to re-seat itself on the mortar, which now has the Bituseal in place.


5. Insert 40mm OD washers and 8 mm nuts over the 20 threaded rods, and finger tighten.


6. Tighten the nuts  on the threaded rods and seal the joint.


7. Test the joint tightness with an ‘inflow test’ . The tank is filled from the top above the expansion chamber and the water level is marked. It is left for 2 hours and checked for the level dropping. If the level remains at the same level, the system is gas tight.