Direct Thermochemical Liquefaction

Bitumen and Asphalt Substitute from Bio-oils/-crudes

Key Points

  • Tar fractions from bio-oils or bio-crudes may serve as asphalt replacements
  • Demonstrations have included macadam (road asphalt) and roofing shingle tar

Further Reading

  • PyNe41, on applications of Phenolic Oil derived from Fast Pyrolysis.
  • PyNe32, Roofing membranes from pyrolysis oils.

Paving Waveland Bike Trail, Des Moines, IA with a mixture of petroleum-based asphalt and phenolic oil. Iowa State University 2017

Asphalts and Bitumen can be partially replaced by a fraction extracted from bio-oils or bio-crudes providing a renewable alternative for fossil bitumen. One specific application demonstrated is the application in roofing material. Bituminous waterproofing systems are designed to protect residential and commercial buildings. Bitumen is a mixed substance made up of organic liquids that are highly sticky and viscous. The unique properties of the bitumen such as sustainable water resistance, excellent adhesion and easy handling are the main reasons for use.

An example application is presented in PyNe41 by Marjorie Rover, demonstrating a Bioasphalt via the use of Phenolic oil derived from cornstover, red oak wood, and switchgrass. This phenolic oil was blended with three common asphalt binders and evaluated for high temperature rheological properties, short term aging, inter temperature rheological properties, long term aging, and low and high temperature rheological properties. The addition of phenolic oil to the asphalt binders caused a stiffening effect resulting in increased high and low critical temperatures. Overall, the tests showed beneficial effects of using phenolic oil in asphalt at high and medium temperatures.

A section of the Waveland Bike Trail, Des Moines, IA, was selected for a demonstration project. Approximately 900 feet of the 10 foot wide trail was paved in fall of 2010 with a 2 inch layer of asphalt containing 3% phenolic oil from heavy ends bio-oil. Evaluation of the project is still ongoing.

Another example use is taking a fraction of the pyrolysis oil, a modified ‘lignitic fraction, is suitable as a raw material for the BIOtumen. This lignin is extracted from the raw oil and yields for the lignitic precursor are around 25 to 30 wt% of the pyrolysis oil. The pyrolytic lignin is subsequently further thermally treated to make it suitable for the processing into roofing materials. Belgium company Derbigum produced approximately 1200m2 roofing membranes replacing a few percent of the bitumen by pyrolytic lignin. This roofing material was placed on a residential complex in Nijmegen, as well as on a private house in Enschede, both situated in the Netherlands.


“Applications of Phenolic Oil derived from Fast Pyrolysis”, Marjorie Rover, PyNe41, 2017, pp 8-10.

“Biotumen: Roofing membranes from pyrolysis oil”, Hans Heeres, PyNe newsletter No 32, 2012, pp 11-12.