DBFO of Sludge treatment facilities
Aquafin nv developed a sludge digestion strategy which in 2015 resulted in the digestion of 52% (52 333 Ton Dry Solids) of the total sewage sludge production. Therefore, seventeen existing digesters were adapted to present day’s standards. In addition 3 new digesters were built using in-house design know how. The degradation of sludge results in the production of biogas. This biogas is an energy source that consists of approximately 65% methane, which can be converted into both heat and electricity. Generating electricity is done by means of gas engines, with an electrical power of 200 to 500 kWh. The cooling heat of the gas engines is used to heat the sludge digesting tanks and in several cases, for the heating of service buildings. The electricity is furthermore used at the treatment plant. The 17 Digestors, with a total volume of 56 600 m³, produced in 2015 approximately 12.33 mio m³ Biogas. A volume of 96.000 ton DS was converted into Biogas. This volume of gas produced 11,98 mio KWh Electrical and 17,7 mio KWh thermal energy source.