SynGas Auxiliary Firing Module

SynGas Auxiliary Firing Module

The solution of auxiliary firing is aimed at power plants and cement plants that, despite the recent ban on mixing sewage sludge ash with ash from other fuels (Sewage sludge Ordinance, AbfKlärV), would like to carry out co-incineration of sewage sludge. With the SynGas Auxiliary Firing Module, the sewage sludge is gasified in a separate SynGas fluidized bed reactor and the synthesis gas is fed to the power plant or cement plant as a gaseous substitute fuel.

The resulting sewage sludge ash is collected separately and, as with our other solutions, is available in the same decontaminated and low-carbon quality for further recycling or potential phosphorus recovery. The expenditure for synthesis gas treatment prior to the transfer point to the power plant can be adjusted according to the customer’s requirements.

Advantages SynGas Auxiliary Firing Module


  • Efficient energetic use of sewage sludge energy
  • Separation of material flows to meet the legal requirements for phosphorus recovery
  • Utilization of existing infrastructures, operating parameters and permits
  • Possibility of sewage sludge drying by existing waste heat
  • 15 years of competence and experience in the field of automated synthesis gas generation


  • Generation of an ignitable gas as alternative to fossil fuels
  • Reduction of CO2 emissions
  • Conservation of resources
  • Contribution to the circular economy through phosphorus recovery
  • Minimization of public investments for new mono-incineration plants


  • Long-term securing of the availability of the secondary fuel sewage sludge
  • Securing revenue from sewage sludge acceptance

Process description fuel gas module

Thermal treatment
1) Sewage sludge with a dry content of 85 – 95 %
2) Sub-stoichiometric combustion at 870 °C to produce synthesis gas
3) Discharge and cooling of the phosphorus-rich and almost carbon-free ash granulate

Synthesis gas scrubbing and transfer
4) Coarse dedusting of synthesis gas in the cyclone to increase the phosphorus yield
5) Transfer to consumer and use of existing flue gas cleaning infrastructure

Flue Gas Cleaning

Flue gas cleaning takes place together with the exhaust gases from the power or cement plant without any further modification in the existing process. The flue gas cleaning system may even be relieved, since the combustion of the synthesis gas can be much cleaner than the combustion of the solid material.