Roofing and asphalt could be getting a lot greener thanks to a new development that could replace bitumen with a renewable, plant-based option. Presented at a meeting of the American Chemical Society, the research shows that lignin, a component of plant biomatter that is removed as a waste product during the paper making process, could be integrated into the bitumen to create a more sustainable sealant option. Because bitumen is an oil byproduct, the supply and cost can fluctuate with the oil market in addition to being fossil fuel-based. Lignin, by contrast, is both produced in plentiful amounts and is a renewable resource.
The researchers from TNO, a non-profit based in the Netherlands, demonstrate that by integrating the two materials on a molecular level rather than mixing them, the amount of bitumen needed could be cut by as much as 50%. Additionally, the scientists have developed mixtures specially designed for warm and cooler weather, using different amounts and formulations of the lignin to reduce the chances of the material becoming too brittle or too tacky.