Sewage sludge to power Russian town

Stuttgart Germany - Plant engineering company Hager + Elsässer of Stuttgart, part of the SH+E Group, has developed an advanced energy-from-waste system for a municipal sewage plant in Russia.

The Euro38 million contract will see Hager + Elsässer serve as general contractor for the state-subsidised “Tschisty Don” (Clean Don), in Rostow, southern Russia.

The public tender specified a system for the disposal of both primary and secondary sludges, which were being dewatered in lagoons. The contract involved planning and building of a complete sludge treatment plant for a population of around 1 million.

Hager + Elsässer has developed a plant to carry out fermentation, drying and final incineration of the sludge. An optimised combination of a three-step process will results in an electrical energy output that significantly exceeds the plant’s own energy consumption, it said.

Biogas produced in the fermentation stage is converted into electrical energy by cogeneration. Then the residual sludge is dried in a belt dryer before being incinerated. The heat from the exhaust gas is then again converted into electrical energy by an ORC turbine.

Excess output will be fed into the public power grid of the city of Rostow.