SynGas CHP Module
The CHP module is characterised by its particularly high electrical energy recovery from the dried sewage sludge. The synthesis gas produced in the fluidised bed reactor is converted into electricity and heat after a purification stage in a highly efficient combined heat and power plant (CHP). The electrical energy is used to cover the plant’s own needs or to feed into the grid, the heat for sludge drying. Since a large part of the energy contained in the synthesis gas is converted into electricity in the CHP module, less thermal energy is available for drying the sewage sludge. This energy deficit can be covered by using the available energy from digester gas. The waste heat from the drying process is in turn available for heating the digestion towers. Thus, the entire system remains thermally self-sufficient and the use of further energy sources is avoided.
If heat has to be extracted for heating the digesters, the digesters can henceforth be heated using the recoverable low-temperature waste heat from the sewage sludge drying process. This means that the entire system remains thermally self-sufficient without the need for an additional energy source.
- Utilisation of the high efficiencies of CHP units
- Patented technology
- Compact flue gas cleaning due to small air mass flow during gas generation
- Technological contribution to an energy self-sufficient wastewater treatment plant
Thermal treatment
1) Sewage sludge with a dry matter content of 85 – 95%.
2) Limestone for admixture as first desulphurisation stage
3) Sub-stoichiometric combustion of the carbon at 870 °C to produce synthesis gas. Destruction of all organic toxins
4) discharge and cooling of the phosphorus-rich and almost carbon-free ash granulate.
Synthesis gas purification and cooling
5) Coarse dedusting of synthesis gas in the cyclone to increase the phosphorus yield.
6) Heat recovery from synthesis gas to be provided in the fluidised bed reactor
7) Fine dedusting of the synthesis gas
8) Synthesis gas scrubbing: further cooling of the synthesis gas and separation of dust residues, tar and pollutants dust residues, tar and pollutant gases
9) Activated carbon filter to remove heavy metals and remaining pollutants
Energy generation
10) Utilisation of the purified synthesis gas in a combined heat and power plant for the generation of electricity and process heat
11) Heat recovery from the exhaust gas of the CHP unit