Harmick Engineering develops method to produce sugars, ethanol from wood chips

A U.S. engineering firm has been granted patents in Canada, the U.S. and Russia for the extraction of arabinogalactan and taxifolin from larch (tamarack) wood chips.

Harmick Engineering’s CelloFuel Portable Biomass Refinery allows mills to produce sugars and ethanol from sugar beet, sugarcane, sweet sorghum, softwood wood chips and straw.

The company has developed a technique for the larch byproduct extraction at its Minneapolis, Minn., facility that is scalable to the sizes needed for large pulp and paper mills.

The technology was created in consultation with a research institute in Saint Petersburg, Russia with experience working with arabinogalactan and taxifolin.

Larch wood chips are much more valuable for making pulp and paper if the arabinogalactan (a biopolymer) and taxifolin (a flavonoid) are first removed, but this has been historically difficult and so few pulp and paper mills will currently accept larch (tamarack) wood.

“We’re very excited about these excellent test results after many years of working on this technology,” says Ed Hamrick, president of Hamrick Engineering.

“Our aim is to find partners in some of the large pulp and paper mills in Russia and Canada. These mills have access to millions of tons per year of larch wood and have the infrastructure in place for harvesting, chipping and pulping this wood. Our technology is a simple, low-cost add-on to existing pulp and paper mills.”

The process

A dilute ethanol solution is infused into the chips in the same way (using steam) that sodium hydroxide is infused into wood chips in a paper mill. This produces an aqueous solution of arabinogalactan and DHQ at the bottom of the column and anhydrous ethanol at the top of the column.

This aqueous solution can be directly spray-dried and sold as a product, without further processing.

Arabinogalactan and taxifolin have additional uses – they have been shown to have “significant probiotic effects” in both people and animals, and can aid in producing animal feed without antibiotics that can be labelled as “organic.”

After extraction of the arabinogalactan and taxifolin, the paper produced from these chips is much stronger and more valuable than the paper produced without this extraction.

Hamrick Engineering predicts making arabinogalactan extract (with seven per cent taxifolin) for less than $1/kg. The market price of taxifolin is about $1/g, so the expectation is to get about $70 of taxifolin for every kilogram of extract.

The cold-water soluble part of the extract is 98.3 per cent arabinogalactan. Taxifolin isn’t soluble in cold water.

Larch wood from northern Minnesota contains about seven per cent arabinogalactan and contains up to 15 per cent in parts of Russia.