Wood gasifier with sewage sludge drying

Sewage sludge drying Wunsiedel

Approval procedure according to 4. BImSchV for a sewage sludge drying plant with a wood gasifier combined heat and power plant

The market for sewage sludge disposal is still undergoing legal changes. Previously possible disposal methods are becoming scarcer, and rising acceptance prices provide the economic basis for alternative concepts. This market situation and the experience gained from many years of operating an existing sewage sludge drying plant have prompted the client to implement a similar concept at the Wunsiedel site.

In addition to the sewage sludge drying plant, a wood gasification combined heat and power plant is to be built to provide the heat needed for drying in a regenerative and environmentally conscious way. The regeneratively generated electricity will be fed into the public grid.

For such plants, there is a need to carry out an immission control approval procedure.

Key data on the project

Burkhardt GmbH

Tradition and constant innovation have made the Burkhardt company from Mühlhausen near Neumarkt i.d.Opf. what it is today: one of the leading German companies for energy and building technology.
With its solutions in the field of wood gasifiers with combined heat and power plants and efficient sewage sludge drying, it not only inspires its customers, but is also an operator of its own in-house plants.

Industry sector

Energy generation and waste utilisation

Project location


Target group

Municipalities (disposal, waste recycling)


Biomass, pellets, wood gasifier, sewage sludge drying, combined heat and power, process heat from bioenergy, forest wood chips, permit application, expert opinion

Technical data

  • Sewage sludge drying: up to 50 t/day
  • Wood gasification CHP: 4 x 180 kWel 1 x 340 kWel
  • Natural gas boiler (peak and reserve boiler): 1.000 kWth
  • Walking floor as day bunker
Klärschlammtrocknung Wunsiedel - Energieberatung Wunsiedel

Customer benefits

Smooth process flow with optimised processing time.

Full support by eta Energieberatung in the context of the immission control permit application as well as coordination of the required environmental reports and the parallel building application. This allowed the client and its partners to concentrate on the core competences of project implementation.


The basic concept includes efficient electricity and heat generation from wood pellets as well as low-temperature sewage sludge drying.

An immission control permit was required for the project.


Granting of the permit in accordance with the 4th BImSchV for the construction and operation of the plant.

For Burkhardt GmbH, it was particularly important to find a planning office that had the necessary experience with wood gasifiers and combined heat and power plants, as well as a good reputation in the energy sector. The comprehensive support provided by eta Energieberatung in the context of the immission control permit application as well as in the coordination of the required environmental reports and the parallel building application led to a smooth process flow with optimised processing time.

Claus Burkhardt
Sales Management Burkhardt GmbH 

Scope of services

The service provided by eta Energieberatung comprised those planning services resulting from the requirements for the application to the competent licensing authority for the construction and operation of a sewage sludge drying plant with bioenergy production.

In particular, this concerned the following engineering and consulting services:

  • Necessary basic evaluation and concept check for the technical equipment for the submission of an application
  • Coordination and further development of the results of the preliminary and draft planning for approval planning
  • Preparation of the permit application including coordination, agreement and compilation of all documents required for this purpose
  • Integration and coordination of the additional parallel planning services for the required structural measures (preliminary, draft and approval planning) as well as the externally processed expert reports (noise, emission, waste and environmental reports) for the submission of the application.
  • Communication with representatives of the authorities to ensure compliance with the content requirements in connection with explanations on the incorporation of technical detailed topics of the project

Let us help you to realize your concepts

We would be happy to help you solving your questions on the use of biomass and on the planning and optimization of heating plants.


We will find the tailor-made solution for you too.


Call me without obligation or write me an e-mail.

Andreas Reichel

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