MBSA Biogas Plant

*Design and Components* ^Thesis ^by ^Kevin ^Chapon

• Plug flow type digester

• Main part is a fibre re-enforced PVC bag of 10 m^3 for anaerobic digestion

• Inlet/outlet dimensions: 110 mm PVC pipe

• Gas connection: 3/4″ thread

• Air input is aquarium pump injecting air in the bag through a small plastic hose

• Small plastic valve controls the air flow in the system

• Electricity supply for the pump is realized by a small PV system of 20W and a battery to store the electricity

Additional Components:

• Condensation Trap

• Flow Meter

• Pressure release system with pressure meter

• Valves: 3 valves are added to the gas network to control the direction of the gas

• Connection to multifunction platform burner

The flat dimensions of the system are 7 x 2.6 m

Digester dimensions: 2.6m x 7.0 m

Training needs and support provided by MBSA staff

Unknown.

Testing of biogas input and performance and effectiveness of liquid/ solid separation for use as a fertilizer were conducted in 2011 by Kevin Chapon from AVANS Hogeschool working with MBSA and FACT – these are some of the findings:

• The hydraulic retention time of the system is set at 50 days so the daily input of feedstock is 1/50 of the digester volume.

• Wet mixture represents 6 m^3, so the daily input should be 120 liters

• The supply of the digester started with 35 kg of cattle dung associated to 55 liters of water during the first month. The amount of manure was decreased by 5 kg every two weeks while adding Jatropha press cake to the mixture. After two and a half months, the digester was supplied by 15 kg of manure and 8 kg of Jatropha press cake.

• The average daily biogas production is 2.71 m^3/day

One of the by-products of the digester is hydrogen sulphide, a colorless, very poisonous, flammable gas with the characteristic foul odor of rotten eggs at a concentration up to 100 ppm ^Thesis ^by ^Kevin ^Chapon