First bio-asphalt road section tests in Zeeland

The collaboration between Wageningen UR Food & Biobased Research and the Dutch Asphalt Knowledge Center(AKC) started with the idea of using lignin as a replacement for bitumen – an idea which, a year and a half down the road, has led to the laying of this trial section in Zeeland. The test is being realized in Sas van Gent, together with other partners in Zeeland, including contractor H4A, Zeeland Seaports and Economische Impuls Zeeland.

Sustainable applications with lignin
Last year, researchers working in the Food & Biobased Research laboratory in Wageningen made the discovery that lignin could serve as a high-quality biobased substitute for fossil-based bitumen. ‘We found that lignin possessed properties that were very similar to bitumen’ said Richard Gosselink, coordinator of the Lignin Platform at Wageningen UR. Lignin is a sticky substance, is easy to process and matches the performance of bitumen as regards UV and dimensional stability. The result is, says Gosselink, an asphalt surface with hardly any swelling or shrinkage in rain or sun.

Lignin is used in a host of interesting applications ranging from vanilla and bio-aromatics (for the chemical industry) to fuel additives. In the near future, Wageningen UR will be setting up a project to investigate the substitution of other bitumen products, more specifically, roofing, in this case, by lignin.

Substantial market
The Netherlands has an almost insatiable need for asphalt, not only for building new roads, but mainly for maintenance and repairs to the existing network. Annually, some 10 million tons of asphalt with a bitumen content of 4-5% are produced and laid. Replacing this petroleum-based material by lignin would therefore yield an enormous sustainability benefit.

And there is no shortage of lignin, now or in the future. The substance that gives plants their sturdiness and structural integrity is released during the production of pulp in the paper industry. Another, at least as copious, waste stream originates from the production of second-generation bio-fuels (ethanol).

Less traffic noise, better fuel economy
In Zeeland, three 70-meter road segments have been laid with the bio-asphalt: one with low temperature asphalt, one with low temperature lignin asphalt, and finally a reference segment with traditional high temperature asphalt. The test trajectory is situated on a straight road without traffic lights to ensure equal conditions. “We will be studying whether lignin improves the rolling resistance of the asphalt,” explains Gosselink. “This would reduce road noise and provide better fuel economy, yielding additional savings in fossil fuels.”

The test sections will be studied for a period of two years.(KL)

http://www.wageningenur.nl/nl/Expertises-Dienstverlening