Project meeting of STEP at the site of the company ATS - Agro Trading & Solutions in Hardegsen (Photo: DBFZ)

Heat Power Biogas Biofuels

Project ID 03EI5404

HydroCarbCO₂ - Hydrothermal carbonization with CO₂ addition for the energetic utilization of sewage sludge with coupled phosphorus recovery


  • 01.01.2020 — 31.12.2022


TUM Campus Straubing for Biotechnology and Sustainability
Professorship of Regenerative Energy Systems
Schulgasse 16
94315 Straubing

Prof. Dr.-Ing. Mathias Gaderer – project leader
Telephone: +49-(0) 9421 187-100

Szymon Herdzik – direct contact person / project coordinator
Telephone: +49-(0) 9421 187-168


Associated partners

03EI5404 - Straubinger Stadtentwässerung und Straßenreinigung (SER)
03EI5404 - ROHRDORFER Südbayerisches Portland Zementwerk Gebrüder Wiesböck & Co. GmbH

Cooperation partners


03EI5404 - TUM-Tech GmbH


Planned results:

Plant level: procedure, technical center plant

Data level: models/modeling

Publications: scientific paper (ISI, peer-reviewed)


HydroCarbCO2 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 need for new sewage sludge treatment concepts is encouraged by the 2017 amendment to the Sewage Sludge Ordinance. The amendment 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.


The aim of the project is to develop an improved process for the use and treatment of sewage sludge. 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.


TUM Campus Straubing for Biotechnology and Sustainability

  • Procurement, construction and commissioning of the laboratory plant
  • Experimental investigation of hydrothermal carbonisation
  • Process simulation of the entire system
  • Evaluation of the carbonisate as a fuel for the cement industry
  • Phosphorus precipitation and biogas production from process water
  • Validation of the laboratory results at a test plant
  • Overall evaluation of the process


TUM Campus Straubing for Biotechnology and Sustainability

  • Experimental and simulative study
  • Science and research


Project Search


Further networking

Project database