Head of Department
Tel: +49 211/6707 – 366
Co2 reduction and energy efficiency
The BFI has been working for many years on ways to reduce the energy demand of individual plants as well as interconnected plants and systems, and has successfully implemented these solutions in collaboration with enterprises in the process industry. In addition to this, measures have been developed and applied industrially to reduce emissions and keep them within regulatory limits. In all of these projects, the main goal has been fitness for industrial use. A few examples:
Waste heat utilisation
We develop a variety of concepts to utilise waste heat for different purposes, such as preheating fluids or generating power, and apply these concepts in practice. In the course of a collaborative project an ORC plant (Organic Rankine Cycle) was successfully installed for the first time in an SME forging business to generate electricity from the arising waste heat. The plant generates up to 300 kW. The project was recognised with an award by KlimaExpo.NRW (see NEBS).
The generation of electricity from waste heat using a TEG (thermoelectric generator) at temperatures above 500° C is being implemented industrially for the first time in a joint effort with partners in the iron and steel industry (see INTEGA, PowerGETEG). Systems are being developed and optimised to convert radiation or convective waste heat to electricity.
With a view to continuously improving energy efficiency, the BFI assists companies in setting up energy management systems in accordance with DIN EN ISO 50001. We accompany them all the way through to certification, e.g. by the TÜV inspectorate. We also conduct energy audits based on DIN EN 16247-1. We assess the potential for improving energy use against the latest state of the art, advise you on defining targets and help you to identify the measures required for improvement.
To ensure homogeneous temperature distribution in thermal process plants, pieces of equipment like metal fans are often installed directly in furnaces. For the temperature range of 800°C to 1250°C, the BFI and its partners have jointly developed and tested a ceramic impeller for a ventilator (see INCERV). This has made it possible to run different heat treatment processes flexibly in one plant, for example. And for the first time it has enabled more precise adjustment of the temperature distribution in the furnace in the high-temperature range.
Innovative surface textures were developed in collaboration with industry partners to extend the life of tuyeres in the blast furnace. These textures reduce the accretion of deposits on the tuyere from the liquid metal (see Longlife BF). Thanks to the new surface texture, local overheating due to hot metal run-off can be prevented.
To reduce energy losses from water-cooled furnace rollers in hot-dip galvanising lines, for example, the BFI has worked hand-in-hand with industry partners to develop innovative new stock transport rollers (see STEBGUT). Depending on the design and execution, practical tests at furnace temperatures of up to 1300°C showed that the cooling power of the new furnace rollers could be reduced by 10–20%.
In-process heat recovery
We have developed heat recovery systems to reduce the heat losses from waste-gas streams. The recuperator and regenerator systems can be used at high temperatures up to 1200°C (see REKUKER, OptiReg 2). These systems have been successfully employed in industry, e.g. on forging furnaces, for many years. The ceramic heat transfer bodies in the recuperator systems are produced by the innovative 3D printing method.
Initial tests have been successfully completed on the BFI’s own 2 MW pilot plant. These delivered very good heat recovery results at operating temperatures up to 1250°C.
Process gas utilization
Aiming to use of primary energy carriers sustainably, the iron and steel industry employs different approaches, one of which is utilising the process gases it generates to fire thermal processing plants. This presents special challenges, particularly when using gases with low calorific values.
We analysed, refined and individually optimised various firing concepts to ensure efficient fuel gas utilisation. This included measuring and regulating variations in gas composition, preheating the media to 1250°C and enriching the combustion air with oxygen. To do this, measuring systems for fast and precise determination of combustion parameters were developed and installed on industrial equipment.
Rational energy utilisation through model- and rule-based process management
To improve the energy efficiency and process stability of manually controlled facilities in particular, model- and rule-based control systems are developed which use current measured data and model-predictive computation to alert operators early when the process needs manual intervention. The control systems also monitor the measuring instruments and the start-up and transition states.
The process is automatically analysed and the energy inputs and feedstocks are adjusted automatically as required. Intelligent control of the energy input makes the process more regular and reduces the energy demand (see Rensodyn, AdaptEAF, PlantTemp).
Optimisation of processes in the electric arc furnace
To lower energy consumption and CO2 emissions the complex processes taking place in the EAF are investigated and improved with the help of numerical simulation and the balance models we have designed. New methods will have to be developed in order to perform the simulation calculations within acceptable computing time and memory capacity limits (see SimulEAF).
Optimising the energy use of auxiliary equipment
Because of its very nature, the production and processing of steel demands a great deal of energy. Most of the energy optimisation measures are directed at the main plants and systems in the production chain. The ÖkoSys project systematically analyses the secondary plant and equipment and suggests possible approaches for energy-optimised operation of these auxiliary facilities which – taken as a whole – also offer great savings potentials.