Assessing HTL-oil as a renewable component for bitumen

Purpose and goal:

This project is to determine whether a bio-oil produced by hydrothermal liquefaction (HTL) is suitable for bitumen application. A bio-oil with increased viscosity has been produced from properly selected biomass under optimized HTL conditions. The formulated bituminous binder incorporating the HTL-oil fulfilled most of asphalt paving specification criteria.

Satisfactory long-term aging properties were also observed for the binder. Although there was an issue concerning storage stability, the HTL-oil showed its potential as a renewable component in bitumen. Expected results and effects:

Experimental results indicated that bituminous binders may be formulated by incorporating the HTL-oil produced from wood-based biomass. The use of such a bio-based material in bitumen would contribute to reducing the climate impact of asphalt paving in road construction. This also shows a potential wide use of biomass from the forest industry.

Approach and implementation:

The project consists of two work packages carried out by three partners who have different areas of expertise and experience. It was a challenge to produce enough amount of the HTL-oil for bitumen investigation. Great effort has been taken to develop and optimize various experimental conditions. Good collaboration between the partners made it easier to share knowledge and to find a way going forward. In general, the outcome of the project is satisfactory.