A high-quality road network, reduced dependence on oil and smart use of a residual product that would otherwise disappear in the incinerator: Dutch society benefits from the large-scale application of bio-asphalt. The secret? Lignin, a substance from the cell wall that gives plants and trees their strength. This allows us to use biomass as a sustainable material instead of fuel. After several successful tests by research institutions, the business community now also sees potential in this application.
Just as sturdy
The road construction sector wants to gradually phase out the use of bitumen from petroleum, the common asphalt binder. Not only for sustainability reasons: in recent years the quality of bitumen has deteriorated because the industry is increasingly extracting high-quality components from it for other applications. Lignin is a good substitute for bitumen. The vegetable substance is released in enormous quantities as a residual stream in all kinds of industrial processes, such as paper production. Such a residual flow deserves a better second life than as fuel.
Noise reducing
This innovation allows us to significantly reduce the bitumen content and produce and apply the asphalt around 30°C less hot. This saves large amounts of CO2 and the use of fossil raw materials. Moreover, this application of biomass is interesting because it allows you to capture CO2 for decades instead of emitting it immediately. Bio-asphalt also reduces noise. The potential of bio-asphalt is therefore enormous and it is expected that it will be able to compete with traditional asphalt.
Scaling up
On Friday, October 2, 2020, a road surface intended for everyday use will be constructed with lignin-containing asphalt for the first time in Vlissingen. The lignin comes from a Stora Enso pulp mill in Finland, but there is much more lignin available for this large-scale application. If the experiences with this road surface are positive, a large-scale rollout will follow in the rest of the country. Home-grown lignin can also be used.
Pioneering role
There is a lot of interest in bio-asphalt at home and abroad. The Netherlands is leading the way in making road construction more sustainable and has a unique knowledge position in the field of bio-asphalt. This is partly due to a special collaboration. The driving force is the Circular Biobased Delta foundation, a partnership of companies, knowledge institutions and governments from across the country. The foundation started an innovation program to stimulate the development and commercial application of lignin-containing asphalt: CHAPLIN (Collaboration in aspHalt Applications with LIgniN). The entire chain, from raw material supplier to end user, is represented in this consortium. Participating research institutions are Utrecht University and Wageningen Food & Biobased Research. In this specific Vlissingen case, H4A signed for the construction. The company would like to take the next step in greening road construction and won the tender for the construction of Zeeland bio-asphalt.
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