Wageningen University: 100% biobased binder as a sustainable alternative for bitumen in asphalt

Developing a 100% biobased binder for asphalt. That is the aim of a three-year research project of Wageningen Food & Biobased Research, H4A, Roelofs, AKC and TNO. The new binder will be based on biobased components from side streams of the paper and pulp industry and the agri-food industry.

Wageningen Food & Biobased Research has been working on sustainable alternatives for existing asphalt binders for years. There are currently 25 test sections around the Netherlands with varying compositions in which 50% of the bitumen was substituted by lignin. In practice, a partial replacement of bitumen with the natural binder lignin has yielded significant gains in sustainability. “These gains will increase further if we are able to develop a 100% biobased asphalt binder”, says Richard Gosselink, lignin expert and coordinator at Wageningen Food & Biobased Research. “We aim to substitute all fossil components in the new binder, while at the same time providing a long-term organic carbon storage in this new high-value asphalt product.”

Other biological molecules
The primary goal is for the new asphalt binder to have at least the same functional properties as bitumen. Gosselink: “We have to translate the required properties into the biobased components that we want to use. In order to get the functional properties, we are looking for smart combinations of biological molecules from a previously compiled longlist. The research first focuses on lab research to find the right combinations of molecules. Various components will probably need to be modified in order to give them the desired functional properties.”

Successful collaboration
Substituting bitumen is desirable in more ways than just from a point of view of sustainability. In the future, a shortage of this raw material is expected, as well as a decrease in quality. “H4A and Roelofs want to contribute to a more sustainable society and are switching to biobased alternatives wherever possible. In addition, we want to be ahead of the shortage of raw materials in order to continue to be of service to our customers in a changing world. One can only remain at the forefront of development when innovating and staying ahead of the market,” says Martijn Verschuren, responsible for the innovations and collaboration with chain partners at H4A, and Albertus Steenbergen, Asphalt and Technology manager at Roelofs. “We found the ideal knowledge partner to join forces in Wageningen Food & Biobased Research. We have been collaborating successfully on various research projects for years.”

Asphalt test strip
With this project, the project partners aim to give the market a significant boost towards a bitumen-free asphalt binder. One of the preconditions for the new asphalt binder is that the biobased raw materials required must be abundant. The aim is to deliver a test strip within three years, on which the new asphalt binder has been incorporated and which is suitable for further upscaling. This test strip will also be tested extensively in order to generate the required data and to work towards a introduction on the market.

Consortium
This project, with number BBE-2006/LWV20.045, sees a collaboration between Wageningen Food & Biobased Research, H4A, Roelofs, AKC and TNO. The partners are grateful to the Ministry of Economic Affairs and Climate Policy for the necessary TKI supplement funding.