A greener alternative to plastics: liquid wood

Giving cast-off lignin a second look
Terry Collins, leader of the Carnegie Mellon Institute for Green Science in Pittsburgh, Pa., said in an e-mail that the German liquid wood manufacturing process “sounds very encouraging indeed,” though he warned that as “with all potentially green alternatives, devils can lie in the details.”

Collins, a professor of chemistry, said that if he was advising Tecnaro on the commercial potential of Arboform, he would recommend a variety of toxicity assays and include a reasonable amount of analysis of the compounds in the extracts from a representative set of wood sources.

“Over time, I would be asking for ever more sophisticated analyses,” he said, “and if the product is to become a major one that children will be exposed to, I would like to see multigenerational animal studies done on appropriate extracts to develop good evidence that developmental disruption is unlikely to be associated with the products.”

So far, Eisenreich said, commercial interest in liquid wood applications has been stronger in Europe than in the United States, though he hopes a shift toward more environmentally friendly solutions in the U.S. may help boost interest here as well.

When crude oil topped $100 dollars per barrel, “this was the best situation for this company,” he said, noting that the accompanying rise in the price of plastics led to multiple new orders for Tecnaro’s test products.

With lignin widely available throughout North America, he said the liquid wood manufacturing process could provide a compelling new use for a home-grown raw material.

Robert Norris, leader of the Polymer Matrix Composites Group at Oak Ridge National Laboratory in Oak Ridge, Tenn., said the effort to find more renewable replacements for petroleum-based products similarly led his group to investigate the use of lignin as a precursor for carbon fiber.

Lignin can be spun into a fiber, he said, “and you burn off everything but the carbon to achieve a higher stiffness and strength from the carbon fibers.”

Lignin is an attractive source because it is relatively cheap and contains a high percentage of carbon.

Although increased efficiencies in the papermaking process have cut back on lignin waste, the biomaterial is still widely seen as having little value apart from fuel.

But as paper companies begin to feel more pressure from importing wood, Norris said, they’re looking at new uses for lignin that could boost its value beyond even that of their primary paper products, providing a new opportunity for manufacturers of carbon fibers or liquid wood to make their case. Ditto for a slew of other companies.

According to the Lignin Institute, a trade association of lignin manufacturers in North America, “Lignin uses have expanded into literally hundreds of applications — impacting on many facets of our daily lives.”

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