Could tree roots, twigs and branches one day be used to power cars? That's the hope of a Swedish researcher who has developed a pulp byproduct that — on a modest scale — does just that.

Chemical engineering scientist Christian Hulteberg, from Lund University, has used the black liquor residue from pulp and paper manufacturing to create a polymer referred to as a lignin.

After purification and filtration, the polymer is turned into a gasoline mixture.

"We're actually using the stuff of the wood that they don't use when they make paper and pulp. ... It adds value to low-value components of the tree," he said.

In environmental terms, he says that gives it an advantage over other biofuels such as ethanol. "A lot of the controversy with ethanol production has been the use of feedstock that you can actually eat," he said.

Hulteberg has a pilot plant in operation and hopes the forest fuel will be available in service stations by 2021.

Though it will only serve a fraction of the demands of Swedish motorists, he is hopeful that, along with other renewable products under development, it could help wean us off our addiction to fossil fuels.