Address: 17 Naberezhnaya Severnoy Dviny, Arkhangelsk 163002 Russian Federation. Northern (Arctic) Federal University named after M.V.Lomonosov. Office 1425

Phone / Fax: (818-2) 21-61-18



Kinetics of Water-Alkaline Hydrolysis of Birch Bark in a Microwave Field. P. 179–190

Версия для печати
Creative Commons License
These works are licensed under a Creative Commons Attribution 4.0 International License.

Elena N. Koptelova, Natal’ya A. Kutakova, Sergey I. Tret’yakov, Anna V. Faleva

Complete text of the article:

Download article (pdf, 0.6MB )






Birch bark consists of silver bark and bast. Silver bark contains up to 50 % of extractives and serves as a raw material for obtaining valuable biologically active substances (BAS), including betulin. A distinctive feature of the birch bark structure is a cross-linked polymer, suberin. Its monomers are suberic acids. They have found use in the production of lubricants, oils, insecticides, fungicides, polymers, polyesters, coatings, etc. A common method for extracting suberic acid salts from silver bark is exhaustive hydrolysis with an aqueous or water-alcohol solution of alkali (NaOH or KOH). We have proposed the activation of raw materials during hydrolysis by using an ultrahigh-frequency electromagnetic field (microwave hydrolysis). Isolation of suberin from silver bark is both a chemical and mass transfer process. Salts that are formed during hydrolysis of suberic acids diffuse to the surface of silver bark particles and pass into the hydrolysate. The limiting stage of mass transfer during birch bark hydrolysis is internal diffusion in the pores (mass conductivity). The anisotropy of the silver bark structure complicates the mathematical description of the mass transfer kinetics in the diffusion process. The process of internal diffusion during microwave hydrolysis is characterized by a steady regime starting from the 4th minute. The kinetics of this process and the effectiveness of diffusion in the tangential and longitudinal directions were determined. As the size of birch bark particles increases in both length (tangential direction) and width (longitudinal direction), the rate of the hydrolysis process and the degree of suberin isolation increase. Internal diffusion coefficients during microwave bark hydrolysis were determined. The highest value was obtained for fractions with a particle size of 3–4.5 mm (silver bark); the lowest – for fractions less than 1 mm (bast). The article shows that the small fraction (bast) should be separated and silver bark should be cut along the fiber in order to increase the yield of suberin after birch bark grinding.


Elena N. Koptelova, Candidate of Engineering, Assoc. Prof.; ResearcherID: AAI-4768-2020, ORCID:
Natal’ya A. Kutakova, Candidate of Engineering, Assoc. Prof.;
ResearcherID: T-1150-2019, ORCID:
Sergey I. Tret’yakov, Candidate of Engineering, Prof.; ResearcherID: S-2192-2019, ORCID:
Anna V. Faleva, Junior Research Scientist; ResearcherID: AAZ-1879-2020, ORCID:


Northern (Arctic) Federal University named after M.V. Lomonosov, Naberezhnaya Severnoy Dviny, 17, Arkhangelsk, 163002, Russian Federation;*,,


birch bark, silver bark, suberin, microwave field, water-alkaline hydrolysis, diffusion coefficient

For citation

Koptelova E.N., Kutakova N.A., Tret’yakov S.I., Faleva A.V. Kinetics of Water-Alkaline Hydrolysis of Birch Bark in a Microwave Field. Lesnoy Zhurnal = Russian Forestry Journal, 2022, no. 3, pp. 179–190. (In Russ.).


  1. Fedorishchev T.I., Kalaykov V.G. Method for Isolation of Betulin and Suberin. Certificate of Authorship USSR, no. SU 382657 A1, 1973. (In Russ.).

  2. Bezumova A.V., Tret’iakov S.I., Kutakova N.A., Koptelova E.N. Extracting Suberin Acids from Birch Bark when Exposed to a Microwave Field. Khimija Rastitel’nogo Syr’ja = Chemistry of Plant Raw Materials, 2018, no. 1, рр. 21–28. (In Russ.).

  3. Kislitsyn A.N. Extractive Substances of Birch Bark: Isolation, Composition, Properties and Application. Review. Khimiya drevesiny, 1994, no. 3, рр. 3–28. (In Russ.).

  4. Koptelova E.N., Kutakova N.A., Tretyakov S.I. Study of Mass Transfer Kinetics during Birch Bark Extraction. Lesnoy Zhurnal = Russian Forestry Journal, 2013, no. 4, pp. 119–128. (In Russ.).

  5. Koptelova E.N., Kutakova N.A., Tretyakov S.I. Removing the Extractives and Betulin from Birch Bark Exposed Microwave Field. Khimija Rastitel’nogo Syr’ja = Chemistry of Plant Raw Materials, 2013, no. 4, рр. 159–164. (In Russ.).

  6. Kuznetsov B.N., Levdanskiy V.A., Es’kin A.P., Polezhayeva N.I. Isolation of Betulin and Suberin from Birch Bark Activated in Conditions of “Explosive Autohydrolysis”. Khimija Rastitel’nogo Syr’ja = Chemistry of Plant Raw Materials, 1998, no. 1, рр. 5–9. (In Russ.).

  7. Kutakova N.A., Bogdanovich N.I., Selyanina S.B., Koptelova E.N., Korovkina N.V. Laboratory Workshop on the Technology of Biologically Active Substances and Carbon Adsorbents: 2 Parts. Part 2. Analysis of BAS. Arkhangelsk, NarFU Publ., 2015. 114 p. (In Russ.).

  8. Makarevich N.A., Tret’yakov S.I., Bogdanovich N.I. Kinetic Model of Mass Transfer at Interfaces with Components of Plant Products. Fizikokhimiya poverkhnosti i zashchita materialov = Protection of Metals and Physical Chemistry of Surfaces, 2019, vol. 55, no. 6, pp. 601–609. (In Russ.).

  9. Makarevich N.A., Bogdanovich N.I., Tretiakov S.I., Koptelova E.N. Kinetic Model of Interphase Processes with Participation of Components of Plant Raw Materials. Khimija Rastitel’nogo Syr’ja = Chemistry of Plant Raw Materials, 2014, no. 4, pp. 251–262. (In Russ.).

  10. Kuznetsova S.A., Kuznetsov B.N., Mihajlov A.G., Levdanskij V.A. Method for Production of Betulin. Patent RF no. RU 2 264 411 C1, 2005. (In Russ.).

  11. Kuznetsov B.N., Sudakova I.G., Kuznetsova S.A., Grishechko L.I., Skvortsova G.P., Veprikova E.V., Levdanskij V.A. Method for Complex Processing of Birch Bark. Patent RF no. RU 2 618 892 C1, 2017. (In Russ.).

  12. Sudakova I.G., Garyntseva N.V., Kuznetsov B.N. Production of Wood Fiber Boards with the Use of Birch Bark Suberin-Derived Binding Agents. Khimija Rastitel’nogo Syr’ja = Chemistry of Plant Raw Materials, 2011, no. 3, pp. 65–68. (In Russ.).

  13. Sudakova I.G., Ivanov I.P., Ivanchenko N.M., Kuznetsov B.N. Protective Compositions for Wood Based on Birch Bark Suberin. Khimija Rastitel’nogo Syr’ja = Chemistry of Plant Raw Materials, 2005, no. 1, pp. 59–63. (In Russ.).

  14. Sudakova I.G., Kuznetsov B.N., Ivanov I.P., Ivanchenko N.M. Film-Forming Materials Production from Birch Bark Suberin. Khimija Rastitel’nogo Syr’ja = Chemistry of Plant Raw Materials, 2004, no. 1, pp. 31–34. (In Russ.).

  15. Tret’yakov S.I., Koptelova E.N., Kutakova N.A., Vladimirova T.M., Bogdanovich N.I. Betulin: Receiving, Use and Quality Control. Arkhangelsk, NArFU Publ., 2015. 180 p. (In Russ.).

  16. Chernyayeva G.N., Dolgodvorova S.Ya., Bondarenko S.M. Extractive Substances of Birch. Krasnoyarsk, ILiD Publ., 1986. 123 p. (In Russ.).

  17. Armbruste M., Mönckedieck M., Scherließ R., Daniels R., Wahl M.A. Birch Bark Dry Extract by Supercritical Fluid Technology: Extract Characterisation and Use for Stabilisation of Semisolid Systems. Applied Sciences, 2017, vol. 7, iss. 3, art. 292.

  18. Ekman R. The Suberin Monomers and Triterpenoids from the Outer Bark of Betula verrucosa Ehrh. Holzforschung, 1983, vol. 37, iss. 4, pp. 205–211.

  19. Ferreira R., Garcia H., Sousa A.F., Freire C.S.R., Silvestre A.J.D., Rebelo L.P.N., Pereira C.S. Isolation of Suberin from Birch Outer Bark and Сork Using Ionic Liquids: A New Source of Macromonomers. Industrial Crops and Products, 2013, vol. 44, pp. 520–527.

  20. Gandini A., Neto C.P., Silvestre A.J.D. Suberin: A Promising Renewable Resource for Novel Macromolecular Materials. Progress in Polymer Science, 2006, vol. 31, iss. 10, pp. 878–892.

  21. Hamanaka S., Suzuki A., Hara M., Nishio H., Otsuka F., Uchida Y. Human Epidermal Glucosylceramides are Major Precursors of Stratum Corneum Ceramides. Journal of Investigative Dermatology, 2002, vol. 119, iss. 2, pp. 416–423.

  22. Kolattukudy P.E. Biopolyester Membranes of Plants: Cutin and Suberin. Science, 1980, vol. 208, no. 4447, pp. 990–1000.

  23. Krasutsky P.A., Carlson R.M., Kolomitsyn I.V. Isolation of Natural Products from Birch Bark. Patent US no. US 6,768,016 B2, 2004.

  24. Krasutsky P.A., Carlson R.M., Nesterenko V.V., Kolomitsyn I.V., Edwardson C.F. Birch Bark Processing and the Isolation of Natural Products from Birch Bark. Patent US no. US 2005/O158414 A1, 2005.

  25. Mandal V., Mohan Y., Hemalatha S. Microwave Assisted Extraction – an Innovative and Promising Extraction Tool for Medicinal Plant Research. Pharmacognosy Reviews, 2007, vol. 1, iss. 1, pp. 7–18.

  26. Microwave-Assisted Extraction for Bioactive Compounds. Ed. by F. Chemat, G. Cravotto. New York, Springer, 2013. 238 p.

  27. Pinto P.C.R.O., Souza A.F., Silvestre A.J.D., Neto C.P., Gandini A., Eckerman C., Holmbom B. Quercus suber and Betula pendula Outer Barks as Renewable Sources of Oleochemicals: A Comparative Study. Industrial Crops and Products, 2009, vol. 29, iss. 1, pp. 126–132.

  28. Pollard M., Beisson F., Li Y., Ohlrogge J.B. Building Lipid Barriers: Biosynthesis of Cutin and Suberin. Trends in Plant Science, 2008, vol. 13, iss. 5, pp. 236–246.

  29. Rižikovs J., Zandersons J., Paže A., Tardenaka A., Spince B. Isolation of Suberinic Acids from Extracted Outer Birch Bark Depending on the Application Purposes. Baltic Forestry, 2014, vol. 20, no. 1, pp. 98–105.

  30. Schweizer P., Felix G., Buchala A., Müller C., Métraux J.-P. Perception of Free Cutin Monomers by Plant Cells. The Plant Journal, 1996, vol. 10, iss. 2, pp. 331–341.

  31. Von Wettstein-Knowles P.M. Waxes, Cutin, and Suberin. Lipid Metabolism in Plants. Ed. by T.S. Moore. CRC Press, 2018, pp. 127–166.

  32. Yang Y., Lu W., Zhang X., Xie W., Cai M., Gross R.A. Two-Step Biocatalytic Route to Biobased Functional Polyesters from ω-Carboxy Fatty Acids and Diols. Biomacromolecules, 2010, vol. 11, no. 1, pp. 259–268.


Make a Submission


Lesnoy Zhurnal (Russian Forestry Journal) was awarded the "Seal of Recognition for Active Data Provider of the Year 2024"