A flagship project for the industry
Austria’s first asphalt mixing plant with hot gas generator system as Retrofit
The Retrofit solution from Benninghoven maximizes recycled material feed-in while offering outstanding flexibility for frequent recipe changeovers and minimal emissions.
Ready for the future: By retrofitting a hot gas generator with counterflow action at its existing facility in Vienna’s Simmering district, PORR now stands to achieve high feed-in rates for recycled material while significantly reducing its carbon footprint for the production of new asphaltic mixture. Another benefit of the retrofit system is the option of maximizing the proportion of recycled material in all recipes. Thanks to the hot gas generator, the RAP material already achieves the end-product temperature of 160 °C,, with high RAP rates being easy to achieve even with frequent recipe changeovers. As the first facility in Austria to have a hot gas generator as a Retrofit, this makes it one of the country’s most innovative asphalt mixing plants and a flagship project for the industry.
The first Austrian facility with a hot gas generator as a Retrofit. With this retrofit, PORR now operates the country’s most modern asphalt mixing plant at its site in Simmering.
PORR is one of Austria’s biggest building contractors and does business throughout the construction sector – including asphalt production. In Austria alone, PORR operates 29 asphalt mixing plants. At the site in Vienna’s Simmering district, some 30,000 tonnes of asphalt are produced with various recipes every month. PORR supplies the City of Vienna with mastic asphalt for track construction and rolled asphalt, and offers a wide variety of recipes to meet the most demanding requirements of its many customers. This huge production volume highlights the facility’s economic efficiency. In line with PORR’s internal closed-loop strategy, which seeks to maximize feed-in rates for recycled material while minimizing emissions and staying as flexible as possible, the company decided to bring its facility up to date by investing in an advanced recycling system. As a strong industry partner, Benninghoven was the natural choice for this project.
“There’s definite market interest in the supply of environmentally friendly building materials and our customers often mention them in their enquiries.”
Karl-Heinz Strauss, CEO PORR
RAP proportion is set to double
Modernization target, first phase: doubling of RAP (reclaimed asphalt) proportion to 40%. “The volume of reclaimed asphalt we’ll be able to process with the new mixing plant will depend on how much RAP is available from road resurfacing,” explains PORR’s CEO Karl-Heinz Strauss. Also important is providing proof that the asphalt produced by the upgraded facility meets all standards for metrics such as rut resistance and bearing capacity. The asphalt must naturally also meet the specifications set out by customers.
Retrofit solution from Benninghoven
Don’t build from scratch – retrofit for sustainability! The hot gas generator from Benninghoven is the leading patented recycling technology and allows operators to produce asphaltic mixture containing up to 100% reclaimed asphalt – and with minimal emissions. As a Retrofit solution, it can be integrated easily into existing facilities – this fact was also instrumental in PORR’s decision to retrofit its existing plant as the first in Austria. Benninghoven not only draws on broad experience in the Retrofit business but also offers an all-inclusive package: expert advice, innovative systems, perfect implementation, and rock-solid support – before, during, and after the project phase. Although a retrofit might sound easy, the reality is highly complex and much more than simply “swapping one part for another.” Benninghoven evaluates and analyzes the process as a whole before working with the customer to decide where and how to integrate the chosen technology.
When it comes to hot gas generator systems, PORR’s Retrofit project has transformed it into a real industry pioneer. The facility is now the first in Austria to be equipped with this innovative technology as a Retrofit.
Installation in two project phases
To keep downtime to a minimum, the installation of the components was planned as a two-stage process.
Hot-gas generator sets the benchmark to beat for recycling
High recycling input rates with low emissions can only be achieved by the counterflow action in the hot gas generator. Here, the recycled material is indirectly heated to the optimum processing temperature of 160 °C and has no contact with the burner flame. “Generally speaking, cutting emissions isn’t a high priority if we have high rates of recycled material. The hot gas generator is a technology that completely avoids 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, intensively heating the circulating air in the recycling drum. This hot air then acts as a gentle and indirect source of heat for the recycled material in the downstream recycling drum, heating it to the final temperature for the RAP material of 160 °C. This capability was the decisive factor for PORR. In Germany, for example, this complies with TA-Luft regulations, and is guaranteed by Benninghoven at all output ranges of the hot gas generator.
Sustainable and cost-effective asphalt production:
More information on this innovative technology and the future of asphalt production from Steve Mac Nelly, Head of Development & Design Engineering at Benninghoven:
“We only feed hot gas to the material in the recycling drum, because the reclaimed asphalt already contains bitumen that would char if we used a direct burner method instead.”
Steven Mac Nelly, Head of Development & Engineering, Benninghoven
Sustainability as part of the PORR closed-loop strategy
Benninghoven is not the only company focusing on sustainable solutions and cutting emissions. PORR is also looking to make its business more sustainable. The deployment of hot gas generator technology marks another milestone the company has passed in its closed-loop strategy. “We aim to replace primary resources with recycled materials wherever technically possible and economically viable,” explains PORR CEO Karl-Heinz Strauss. “There’s definite market interest in the supply of environmentally friendly building materials and our customers often mention them in their enquiries.”
“Technology like this forms an integral part of our strategy for supporting the closed-loop economy.”
Karl-Heinz Strauss, CEO PORR
A sound investment in the future
By installing a hot gas generator system, PORR has made a major contribution to reducing its carbon footprint. Even the use of 60% reclaimed asphalt when producing new asphaltic mixture can cut carbon by 20% within the overall road construction process chain. At the same time, this reduces asphalt production costs, because recycled material is significantly cheaper than quarried virgin material. As a result, the company has not only derived several positive ecological, economical and flexibility benefits from the Retrofit project, but is now better placed to meet customer requirements. Thanks to the stalwart efforts of partner Benninghoven, the entire process was handled with ease and is now seen as a flagship project within the Austrian asphalt industry.
Sustainability at Benninghoven
Sustainable business and reductions to climate-damaging emissions are the current challenges faced in efforts to counteract climate change.
