WSP develops pine-based bitumen alternative in world-first lab trials

Aotearoa New Zealand produces more than 10 million tonnes of pine each year. Lab trials at WSP have now shown that this abundant source of biomass can be converted from solid wood into a binder able to replace crude oil-based bitumen.

Early results are promising, and the potential could be significant.

New Zealand relies exclusively on imported bitumen for road surfacing, leaving the country exposed to global oil markets, shipping disruption, and rising costs. A locally sourced alternative made from pine biomass could improve supply resilience, reduce dependence on fossil fuels and create a lower-emissions road surfacing material from a resource we already produce in abundance.

The material has performed comparably to conventional bitumen in several NZ Transport Agency Waka Kotahi performance standard tests but is still at the laboratory stage. Larger-scale trials, carbon accounting, and investigations into the economics of production are still ahead.

Using Pinus radiata trees, researchers processed the wood and applied novel techniques to break down its lignin and cellulose molecules into a resin-like binder. This behaves just like bitumen; hard when cool, soft when heated.

A patent application has been filed in relation to the technology.

Funded by the Ministry of Business Innovation and Employment’s Endeavour Fund, it has been developed over the past several years through a research collaboration led by WSP and involving Scion, the University of Auckland, the University of Nottingham, and Ngāi Tūhoe.