Gas

Gas produced in the digesters is collected in a 3,400 m³ holder and is transported via two blowers to a gas treatment system.

Biological gas (biogas) contains high concentrations of hydrogen sulfide (H₂S), which is a corrosive gas that may damage the turbines that produce electricity. The hydrogen sulfide gas is decomposed by microbes in a biological reactor.

The biogas is saturated with water and must be dried before it is transferred to turbines that generate electricity. The gas is dried by cooling it to 4°C and by condensing the water vapor.

Biogas contains other compounds that must be removed before its use. This process is performed by passing the gas through an activated carbon filter that absorbs the undesirable compounds.

The electricity generation system uses the biogas produced in the sludge digesters. Electricity is generated with two gas turbines, each having an output of 1250 kwh. The electricity that is produced is consumed in the operation of the treatment plant.

The electricity produced at the power plant provides about one-half of the energy needs of the treatment plant.

Surplus gas that is not used in the generation of electricity is burned by the gas flare. Burning of the surplus gas prevents the release of methane gas into the atmosphere and preserves environmental quality.