Lighthouse project
Austria’s first asphalt mixing plant with hot gas generator technology as a Retrofit
The Retrofit solution from Benninghoven enables maximum use of recycled materials, a high level of flexibility for frequent recipe changes and minimal emissions.
Ready for the future: With the retrofit hot gas generator with counterflow action, the existing PORR plant in Vienna Simmering can handle a high level of recycling materials while significantly lowering the CO2 footprint for the production of new mixtures. The option of using the maximum recycled materials content for all recipes is another benefit of this technology. With the hot gas generator, the RAP material already reaches the temperature of the end product of 160 °C and a high RAP content is easily feasible even with frequent recipe changes. The plant is the first in Austria with a hot gas generator as a Retrofit. This makes it one of the most innovative asphalt mixing plants in the country and it is regarded as a lighthouse project for the industry.
The first plant in Austria with a hot gas generator as a Retrofit Thanks to the retrofit, PORR in Simmering commissions the most modern asphalt mixing plant in the country.
PORR is one of the largest Austrian construction companies and active in all sectors of the construction industry – including in asphalt production. PORR operates 29 asphalt mixing plants in Austria alone. 30 000 tons of asphalt with different recipes are produced at the Vienna Simmering site every month. PORR supplies mastic asphalt for railway track laying and rolled asphalt to Vienna council, offering a large variety of recipes to meet the different requirements of its numerous customers. These huge volumes illustrate how efficient the plant is. In line with the circular economy strategy of PORR that strives for maximum recycled materials content with minimum emissions and maximum flexibility, the company decided to update the plant to the state of the art and invest in the latest recycling technology. Benninghoven was the first point of contact and a strong partner for this project.
“There is definitely demand for eco-friendly construction materials on the market and we keep receiving requests from customers for this.”
Karl-Heinz Strauss, CEO of PORR
Planned doubling of the recycled materials content
Objective of the modernisation: doubling the recycled materials content to 40 % in the first step. “The volumes of reclaimed asphalt that we are now processing with the mixing plant depends on how much is available from road resurfacing projects,” explains Karl-Heinz Strauss, CEO of PORR. Another essential aspect is to provide verification that the produced asphalt meets the standards for values such as rutting resistance and load capacity. In addition, it has to meet the customers’ requirements.
Retrofit solution from Benninghoven
Retrofit instead of a new plant – sustainability starts here! The hot gas generator from Benninghoven is the leading, patented recycling technology and enables plant owners to produce asphalt mixtures from up to 100 % reclaimed asphalt with minimum emissions. As a Retrofit solution, it can easily be integrated into existing plants. This convinced PORR to update the existing plant with this technology – as the first one in Austria. In addition to a high level of experience with Retrofit projects, Benninghoven also offers the complete package: competent advice, innovative technology, perfect implementation and reliable support before, during and after the project phase. Retrofit – it sounds easy, but it is highly complex and entails far more than just replacing old components with new ones. Benninghoven examines and analyses the process as a whole and decides together with the customer which technology will be used where and how.
With the Retrofit project, PORR has adopted a pioneer role in terms of the hot gas generator technology. It is the first plant in Austria to be equipped with this innovative technology as a Retrofit.
Installation in two construction phases
To keep the plant downtime as short as possible, the components were installed in two phases:
Hot-gas generator sets the benchmark for recycling technology
High recycling input rates with low emissions can only be achieved with the counterflow action in the hot gas generator. The recycling material is indirectly heated to the optimum processing temperature of 160 °C and does not come into contact with the burner flame. “It is not our primary focus is to reduce emissions with a high content of recycled materials. The hot gas generator provides us with a technology that does not generate any emissions in the first place,” explains Steven Mac Nelly, Head of Development & Design Engineering at Benninghoven. With the counterflow action, the burner fires into the hot gas generator and intensively heats the surrounding air in the recycling drum. This hot air then indirectly and gently heats the recycled material in the downstream recycling drum to the final temperature of the RAP material of 160 °C. For PORR, this was the deciding factor. The requirements of the TA-Luft regulation in Germany, for example, are met and are guaranteed by Benninghoven in the entire performance range of the hot gas generator.
Sustainable and efficient asphalt production:
Steven Mac Nelly, Head of Development & Design Engineering at Benninghoventalks about this innovative technology and the future of asphalt production:
“This means that we only add hot gas to the material in the recycling drum, because the reclaimed asphalt already contains bitumen that would char if a direct burner method was used.”
Steven Mac Nelly, Head of Development & Design Engineering, Benninghoven
Sustainability as part of the PORR circular economy strategy
Sustainable solutions and lower emissions are a priority not only at Benninghoven. PORR also focuses on sustainable operations. Using the hot gas generator technology is another milestone for the circular economy. “We are aiming to replace primary raw materials with recycled materials wherever this is economically and technically feasible, says PORR CEO Karl-Heinz Strauss. “There is definitely demand for eco-friendly construction materials on the market and we keep receiving requests from customers for this.”
“Technologies such as this one are an essential part of our circular economy strategy.”
Karl-Heinz Strauss, CEO of PORR
A good investment in the future
By using the hot gas generator technology, PORR is making an important contribution to reducing the CO₂ footprint. Even the use of 60 % reclaimed asphalt for producing new asphalt mixtures can cut CO₂ by 20 % over the total road construction process chain. At the same time, the costs of asphalt production go down because recycled materials are much cheaper than the virgin material from a quarry. This means that the Retrofit investment pays off for the company in several ways: ecologically, economically and in terms of flexibility, but also with respect to customer requirements. With Benninghoven as a strong partner, the entire process was handled efficiently and is now regarded as a lighthouse project for asphalt production in Austria.
Sustainability at Benninghoven
More sustainable operations and reduced climate-damaging emissions are the current challenges for counteracting climate change.
