Background and goals of the research project

In cement production, a significant portion of the thermal energy is used to burn the cement clinker in the rotary kiln. Nowadays, alternative fuels (refuse derived fuels, RDF) are used in parallel with fossil fuels, replacing the former. From an economic point of view, cement manufacturers are striving to increase the share of alternative fuels in order to secure or improve their competitive situation. In addition to economic advantages, ecological advantages should also be mentioned. For example, the use of alternative fuels can contribute to reducing climate-relevant CO2 emissions.


Today, processed flyable industrial and commercial waste (solid recovered fuels, SRF) is predominantly used. These are already subject to quality monitoring with regard to certain parameters (e.g. chlorine content, trace element content, etc.). Ideally, SRF should be preconditioned in such a way that it is sufficiently homogeneous with regard to essential combustion parameters (humidity, flying capability, etc.). This makes it easier for the cement plant operator to ensure uniform kiln operation and to rule out any impairment of the clinker properties. The prerequisite for this is that the quality requirements for SRF can be described as precisely as possible, coordinated with the SRF supplier and continuously checked without great effort.

As part of the research project, the German cement industry is to be provided with a utility model of a new type of apparatus for quasi-continuous incoming inspection of SRF deliveries. Based on a fast, technically robust and efficient characterization of flight capability, humidity and optically detectable features of SRF, a system shall be developed, constructed and tested in practice.  Parallel to the project, quality requirements for the SRF will be developed (AiF project 20691 N). The planned system is to be used both by cement plant operators and fuel suppliers.


The IGF project 20898 N of VDZ Technology gGmbH is supported by the AiF within the framework of Industrial Collective Research (IGF) of the Federal Ministry of Economic Affairs and Climate Action on the basis of a decision of the German Bundestag.

Person to contact

Do you have questions regarding this project?

Dr Stefan Schäfer
Environment and Plant technology

+49-211-45 78-252

Other items of possible interest


Research projects

Investigation on the interaction of fuel particles and cement clinker with the aim of increasing the use of alternative fuels

The aim of the research project was to identify those fuel particles which potentially cause the greatest disturbances and to determine their rate of conversion in the flame and in the clinker bed. A further goal was to derive quality criteria for AF, to elaborate recommendations for the optimisation of fuel feeding systems and to develop a tool to estimate the suitability of an AF.

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