VTT: Birch Bark Compounds Offer a Wealth of Business Opportunities

13 Feb 2014 --- Birch is a standout wood species: Half of the weight of birch outer bark consists of betulin and fatty acids of suberin. These compounds can replace pine oil and resin in technochemical products. They can also be used in pharmaceuticals.

VTT is researching and developing the potential for producing birch bark-based products in Finland and their business opportunities.

At the moment, birch bark is mainly combusted for production of heat and electricity. At sawmills and pulp plants, birch logs are debarked mechanically in large drums. Birch bark is thus available in great quantities.

Betulin and suberin fatty acids can also be used in the production of fine chemicals and paints, glues and other such products commonly made using pine oil and resin, as well as in the pharmaceutical and cosmetics industries.

About half of the content of birch outer bark consists of betulin and suberin. The valuable components can be easily recovered from the bark by means of solvent extraction and NaOH treatment before the remainder is combusted.

Betulin is a water-repellent and pure white terpene compound that is harmless to health. Its rigid structure and high melting point make it suitable for use in the production of polymers, resins and coatings, for example. Betulin gives birch bark its white colour. It also has bioactive characteristics that could be highly significant in the future. Currently, betulin is utilised commercially mainly in cosmetics and health foods and supplements.
Suberin is a fatty acid compound that is also harmless to health. Its water-repellent and lubricating properties make it an appealing industrial raw material for polymers, resins and lubricants.

Betulin and suberin fractions can be used to replace pine oil and resin in paints, glues, inks and rubber. Even though many studies have been conducted and few patents granted , no such products are yet on the market due to the high price and limited availability of betulin and suberin fractions. The price of raw pine oil has risen substantially in recent years, and will most likely continue to do so, as the use of pine oil and resin becomes more common in biodiesel production.

VTT is also researching the use of compounds made from betulin as antibodies for viruses, protozoa and bacteria as well as in cancer treatment. Betulin-based substances are a new kind of compound group. In cell culture experiments carried out at VTT, the most potent betulin compounds were highly effective at preventing the growth of microbes and cancer cells.

At present, suberin is not commercially available. The price of high-quality betulin can be as high as several hundred euros per kilo. According to VTT’s preliminary calculations, the production costs of these compounds could in the best-case scenario – that is, when the extraction plant is located at a birch plywood mill – be close to those of fractions produced from raw pine oil.

VTT is currently assessing the production potential of these compounds in Eastern Finland in association with Savonlinnan yrityspalvelut Oy and local companies.