Environmental impact of biogenic oils as raw materials in road construction

ABSTRACT

Replacing fossil with biogenic raw materials is an approach to slowing the consumption of fossil resources and to reducing climate change. However, the use of biogenic raw materials can cause other considerable environmental impacts. This study evaluates the overall environmental impact of the use of biogenic oil in the five main road construction applications in Europe today. In hot spray surface dressing and cold asphalt for repairs, biogenic oils of food crop origin are used to replace solvents. In colourless binders, surface treatment emulsions and rejuvenating agents, biogenic oils of food crop origin are used to replace fossil oils. Based on literature review and expert interviews, the products with biogenic additives could be assumed to have equivalent quality and behaviour in the construction, use and end-of-life phases, so the LCA was restricted to the production of raw materials and the emissions of those materials during the construction phase. In general, binders supplemented with vegetable food crop oils are not advisable from an environmental point of view. The use of food crop oils could only make sense if they are produced from waste oils (recycling) or if a better quality in the construction or use phases is achieved, such as reduced emissions or increased service life. Such improved quality can be achieved not only with biogenic raw materials, but also with those of fossil origin. Based on the literature analysis, it is also recomobilanzen: Methode de “system” as a whole be optimised, i.e. not only its materials but also its use.

KEYWORDS:

• Environmental impacts
• LCA
• biogenic oil
• food crop
• renewable materials
• road construction

Acknowledgements

The authors want to thank the expert group accompanying the study and other experts giving valuable input. We also thank Andrew Brown and Fabio Cortesi for language help and proof reading.

Notes

1. 2.6t plants/ha with 45–50% oil content [cf. potato: approx. 40t/ha].

Additional information

Funding

This study was funded by the Swiss Federal Roads Office [contract number VSS 2010/402].