The 2017 amendment to the Sewage Sludge Ordinance will introduce stricter rules for the treatment of sewage sludge, which should lead to a lower input of pollutants into soils and a greater recycling of valuable components. For example, the spreading of sewage sludge on fields will be more restricted. In addition, operators of sewage treatment plants will be required to use methods of phosphorus recovery in future, if the phosphorus content in the dry mass of the sewage sludge exceeds 20 g/kg.

HydroCarbCO2 (hydrothermal carbonization with CO2 addition for the energetic utilization of sewage sludge with coupled phosphorus recovery) is a project that involves the treatment of sewage sludge using HTC (hydrothermal carbonization) and optimizes this by making extensive use of all process streams. The introduction of CO2 enables coupled phosphorus recovery. The HTC coal formed in the process can be used as a fuel for the cement industry, which removes the pollutants originally contained in the sludge during the exhaust gas treatment or binds them into the cement material. In addition, the energy efficiency is increased by the utilization of the resulting process water for biogas production.


The Federal Ministry of Economics and Energy (BMWi) fund HydroCarbCO2 within the funding initiative "Energetic use of biogenic residual and waste materials".

Project partners:

  • Rohrdorfer
  • Straubinger Stadtentwässerung und Stadtreinigung
  • TUM-Tech GmbH
  • TUM Chair of Energy Systems

Project duration: 01.01.2020 - 31.12.2022

Funding reference: 03EI5404

Contact person: Szymon Herdzik