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. 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. Applications range from glues and paints to pharmaceuticals
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.