From black to green - new partnership rolls out the asphalt of the future

Every year, around eight million tonnes of asphalt are produced and laid each year on Swedish roads and asphalt fields. As sustainability becomes an increasingly important factor in the construction and manufacturing industry, the need for sustainable alternatives has increased. Nynas AB is a company that is continuously working to support the sustainable transition in several areas. In collaboration with RISE, it has looked at new alternative materials to develop bio-extended bituminous binder for asphalt. This work has been carried out using thermochemical conversion processing to convert biomass into bio-oil that can be used as a component in bitumen binder that the industry currently uses.

Xiaohu Lu, Chief Scientist at Nynas, sees great benefits in the collaboration. 

"In the long term, developing bituminous binders with renewable bio-waste products is an important step in finding more sustainable alternatives. Our collaboration with RISE has been very valuable. Through our experience and expertise in our different fields, we have complemented each other well and are building new expertise for the future".

Tomas Gustafsson, project manager and researcher in the chemistry group at RISE in Örnsköldsvik, also emphasises the good cooperation. 

"The company's interest in development and knowledge of the tests needed to evaluate the product, combined with our experience and state-of-the-art infrastructure for research and demonstration, has been a winning concept," says Tomas.

Although the technology developed so far is at an early stage of the process, the project is showing positive results. 

"The thermochemical conversion process used converts most types of organic biomass into liquid oils in one step. It is a technology we have worked with a lot, but not with this particular application, which has been an exciting challenge. With this process, we are opening up new areas of application and ensuring that by-products from the forest industry are utilised and create value in other processes," says Tomas. 

At the moment, the results are being evaluated in a broader perspective and discussions are underway on the next steps for the product, both by refining the process and by carrying out more practical tests in asphalt. 

"It's great to be able to contribute to making the roads beneath us not only sustainable for traffic, but also for the climate," says Tomas.