Thermal process technology

VDZ services in the field of thermal process technology encompass a broad range from high-temperature process measurements to consulting on process optimisation, product quality, energy efficiency and use of alternative fuels and raw materials to process technology modelling. Our measurement technicians and engineers have many years of experience, in the cement industry particularly, but also in other earth materials industries, e.g. the lime industry.

We regularly conduct measurement and optimisation projects for industrial plants (e.g. rotary kiln plants in the cement industry) and know the requirements of everyday operations inside and out. In the completion of research commissions and conduction of publicly funded research projects in the cement industry, we systematically improve our understanding of process engineering and continuously advance our methods.

We can support you as a reliable and independent partner even in complex and interdisciplinary projects. We will be more than happy to advise you and help you find the ideally tailored solution for your problem. We can also perform technical reviews to do so.

Process optimisation

Hauptfeuerung einer Drehofenanlage der Zementindustrie

Maintaining and improving cost-effectiveness and competitiveness requires continuous examination of production processes. Such examination may indicate the necessity to rework a plant to suit future requirements or to install new technology. Our plant specialists’ many years of experience in the cement and earth materials industries are the foundations for pro-fessional support in diagnosing weak points and in developing solutions. Where diagnosis requires, we have extensive equipment for performing measurements in high-temperature processes.

Our services in the field of process optimisation include the following:

Product quality

Erfassung und Bewertung der Klinkerqualität

Our chemicals and mineralogy department will support you in recording and evaluating the status quo at your plant and check how the burning and cooling conditions as well as the raw materials and fuels impact clinker properties.

Energy efficiency

Probenahme von Feststoffen im Rahmen einer Energiebilanz

Energy efficiency is of key importance in the energy-intensive earth materials industries. The aim of VDZ energy-efficiency analyses is to identify potential for savings in your production process.

We also offer to rate your collated energy data against the VDZ database and BAT (best available techniques). This supplies you with a fair and neutral analysis of your fuel and electricity consumption.

The scope for application of the energy-efficiency analysis is defined by your specific requirements. Our energy-efficiency services comprise:

  • Determination and analysis of the energy demand under consideration of the plant-specific production processes
  • Drafting of comprehensive energy balances for kiln plants based on plant data and the on-site measurements performed by our experienced team of specialists (see also measurements in high-temperature process)
  • Rating against VDZ database and BAT
  • Identification and quantification of savings potential
  • Consultation regarding optimisation measurements
  • Export inspection with a view towards CO2 minimisation measures
  • Determination of cost savings potential

Measurements in high-temperature process

Messungen in Hochtemperaturprozessen z.B. an Drehofenanlagen der Zementindustrie

Our measurement technicians have many years of experience with the measurement procedures for high-temperature processes. We are particularly versed in on-site measurements in rotary kiln plants for the cement industry – that is, in exhaust gases with high dust content and at very high temperatures such as occur in the clinker burning process.

This includes measurements of gas composition, dust content and temperatures, for example in the crude gas, riser pipes, kiln inlets, calciners, tertiary air ducting of cement-industry rotary kiln plants. 

We can also conduct measurements in downstream plant sections (e.g. dust filters such as baghouses or electrostatic precipitators, evaporation coolers, SCR systems). Special meas-urements of ammonia (NH3) concentrations, e.g. to optimise SNCR or SCR systems for NOx reduction, are also part of our services.

The key measurement procedures are accredited and subject to regular internal quality checks. We compile test reports summarising the measurement results for you.

Measurements in high-temperature processes:

  • Gas composition
    (e.g. O2, CO, CO2, NOx, SO2, VOC,
    mercury/Hg, total C,
    ammonia/NH3, HCl etc.)
  • Gas flow rate
    at gas temperatures up to 1,200°C 
    (depends on dust content)
  • Pressure
  • Gas temperature with thermocouple up to 1,200°C
    (e.g. tertiary-air temperature)
  • Gas temperature with extractor unit up to 1,200°C at cross-sections of up to 7 m (e.g. secondary-air temperature)
  • Dust content
    (at concentrations up to 200 g/m3)
  • Solids/wall temperatures
    with pyrometer up to 1,600°C
    (e.g. heated clinker temperature, kiln shell temperature)

Sampling and analysis of solids and liquids

  • Dusts in the gas flow (e.g. crude gas, cooler exhaust air)
  • Fuels
  • Raw material/raw meal
  • Clinker

The VDZ labs can analyse the samples, for example to determine:

Alternative fuels/raw materials

Alternative BrennstoffeAlternative Brennstoffe

When using alternative fuels and alternative raw materials, kiln operation, product quality and environmental impact are key aspects.

We can offer professional consultation and support based on our experience from decades’ worth of research and the measurements of kiln plants:

  • Drafting of combustion-technology studies on using alternative fuels/raw materials
  • Effects and substance circulation (sulphur, chlorine, alkalis)
  • Drafting of environmental verification reports
  • Analysis of alternative fuels
  • Thermographic flame testing:
    We use a mobile thermographics system to conduct on-site analysis of the main firing system’s flame. Using the results of this analysis, we create proposals for optimising employment of alternative fuels (for example in regard to fuel quality or fuel mix).
  • Process technology modelling

Process technology modelling

Process modelling is a further tool for process optimisation regarding energy efficiency, emissions reduction or use of alternative raw materials and fuels. The VDZ process model was developed by the Research Institute of the Cement Industry. It comprises plant design and energy and substance conversion and can be adapted to match the plant under scrutiny. It has been applied and validated in many projects.

Using the VDZ process model circumvents the risk of damage inherent in testing setups di-rectly in a kiln plant. It also avoids, or at least reduces, the costs incurred by in-depth meas-urement campaigns. Examples for application of our simulation studies using a direct-to-practice process model include the following:

  • Assessment and design of plant conversions
  • Assessment of planned plant-technology measures before implementation
  • Determination of data that cannot be measured (e.g. kiln profiles for temperatures, gas composition, chemical/mineralogical substance conversion etc.)
  • Effect of plant-technology and process-engineering modifications on clinker quality


Albrecht Schall

+49-211-45 78-309

+49-211-45 78-296

Service offer

VDZ Technical reviews

Technical reviews: energy efficiency – environmental services – product and process optimisation

Quality standards

The management system of VDZ gGmbH is certified by DQS in accordance with ISO 9001.

VDZ gGmbH is accredited by the Germany's National Accreditation Body according to DIN EN ISO/IEC 17025.


Energy efficiency in cement production; part 1

Energy efficiency in cement production; part 1
Hoenig, V.; Koring, K.; Fleiger, P.; Müller, Ch.; Palm, S.; Reiners, J.
In: Cement International. 2013, 11(3), pp.50-67

Energy efficiency in cement production; part 2

Energy efficiency in cement production; part 2 
Hoenig, V.; Koring, K.; Fleiger, P.; Müller, Ch.; Palm, S.; Reiners, J.
In: Cement International. 2013, 11(4), pp.46-65