Production of charcoal by pyrolysis of wood in the presence of an ultrahigh frequency electromagnetic field

Experimental equipment for producing charcoal from sawmill residues using thermochemical conversion of biomass in an oxygen-free environment has been developed. This equipment features thermal conversion of wood raw materials in a pyrolysis chamber equipped with microwave sources. The pyrolysis equipment includes a unit for producing generator gas from organic waste, a wood pyrolysis unit, a pyrolysis chamber purging system with inert gas, an afterburner for the generator gas and pyrolysis gas mixture, a combustion product temperature control unit, a heat exchanger, a smoke exhauster, a pyrolysis unit control and monitoring system, and a chimney. Magnetrons were used as microwave sources. A description of the testing methodology for the equipment for producing charcoal in the presence and absence of a microwave field is provided. Hardwood (split maple firewood) was used in the tests. The results of the study indicate that the use of microwave technology can increase the rate of thermochemical destruction of wood, increase the productivity of equipment for the production of charcoal, and also obtain a higher yield of charcoal per unit mass of the original wood, raw material or product with a higher calorific value and lower ash content.For example, the productivity of the experimental pyrolysis unit without microwaves was 1.42 kg/h, while with microwaves, it was 1.73 kg/h, an increase of 22 %. The developed technology for producing charcoal by thermal pyrolysis in the presence of microwaves offers economic and energy-efficient potential. 

1. Korsak, E. P. Formation of the System of Threats to Energy Security of the Republic of Belarus. Energetika. Izvestiya vys­ shikh uchebnykh zavedenii i energeticheskikh ob”edinenii SNG = Energetika. Proceedings of CIS Higher Education Institutions and Power Engineering Associations, 2019, vol. 62, no. 4, pp. 388–398 (in Russian). https://doi.org/10.21122/1029-7448-2019-62-4-388-398

2. Fortov V. E., Popel’ O. S. The current status of the development of renewable energy sources worldwide and in Russia. Thermal Engineering, 2014, vol. 61, no. 6, pp. 389–398. https://doi.org/10.1134/S0040601514060020

3. Losyuk Yu. A., Zhibrik S. V., Korchinenko S. V. Some aspects of thermochemical conversion of peat. Energetika. Izvestiya vysshikh uchebnykh zavedenii i energeticheskikh ob”edinenii SNG = Energetika. Proceedings of CIS higher education institutions and power engineering associations, 2008, no. 5, pp. 60–66 (in Russian).

4. Bridgwater A. V. Biomass Fast Pyrolysis. Thermal Science, 2004, vol. 8, no. 2, pp. 21–49. https://doi.org/10.2298/TSCI0402021B

5. Mohan D., Pittman Ch. U., Steele Jr. P. H. Pyrolysis of Wood/Biomass for Bio-Oil: A Critical Review. Energy & Fuels, 2006, vol. 20, pp. 848–889. https://doi.org/10.1021/ef0502397

6. Chan W. R., Kelbon M., Krieger B. B Modeling and experimental verification of physical and chemical processes during pyrolysis of large biomass particle. Fuel, 1985, vol. 64, pp. 1505–1513. https://doi.org/10.1016/0016-2361(85)90364-3

7. Bakari R., Kivevele T., Huang X., Jande Y. A. C. Catalytic supercritical water gasification of biomass waste using iron-doped alkaline earth catalysts. Biomass Conversion and Biorefinery, 2024, vol. 14, iss. 6, pp. 7487–7506. https://doi.org/ 10.1007/s13399-022-02800-x

8. Palchenok G. I., Khutskaya N. G., Yantsevich I. V., Moshchina T. M. Macrokinetics and heat and mass transfer in the processes of thermochemical conversion of biomass. Mikhalevich A. A., ed. Vozobnovlyaemye istochniki energii: potencial, dostizheniya, perspektivy: materialy Mezhdunarodnogo seminara ekspertov (Minsk, 22–24 fevralya 2011 g.) [Renewable energy sources: potential, achievements, prospects: Proceedings of the International Expert Seminar (Minsk, 22–24 February 2011)]. Minsk, Belaruskaya navuka Publ., 2011, pp. 206–220 (in Russian).

9. Falyushin P. L., Dobrego K. V., Kraiko V. M., Anufrieva E. V. Pyrolysis of oil shales of the Turov field. Journal of Engi­ neering Physics and Thermophysics, 2011, vol. 84, no. 3, pp. 631–637. https://doi.org/10.1007/s10891-011-0515-7

10. Pantskhava E. S., Pozharnov V. A., Zysin L. V., Farberov V. G., Shramkov V. M., Mayorov N. I., Shkola I. I. Conversion of biomass energy. Experience of Russia. Teploenergetika [Thermal Power Engineering], 1996, no. 5, pp. 33–38 (in Russian).

11. Kosivtsov Yu. Yu., Sulman E. M. Technology of Pyrolysis of Organic Materials: Monograph. Tver, Tver State Techni­ cal University, 2010. 124 p. (in Russian).

12. Apostolov S. A., Babash S. E., Berents A. D., Borutskii P. N., Vasil’ev Yu. V., Vasil’ev S. N. [et al.]. New Handbook of Chemistand Technologist. Raw Materials and Products of the Industry of Organic and Inorganic Substances. Part 2. St. Pe­­ tersburg, ANO NPO “Professional” Publ., 2005. 1144 p. (in Russian).

13. Association of Independent Experts in the Field of Mineral Resources, Metallurgy and Chemical Industry. Market Overview of Activated (Active) Carbon in the CIS. Moscow, 2019. 193 p. (in Russian).

14. Hagemann N., Spokas K., Schmidt H. P., Kägi R., Böhler M. A., Bucheli T. D. Activated Carbon, Biochar and Charcoal: Linkages and Synergies across Pyrogenic Carbon’s ABCs. Water, 2018, vol. 10, iss. 2, p. 182. https://doi.org/10.3390/w10020182

15. Dayton D. A Review of the Literature on Catalytic Biomass Tar Destruction. Milestone Completion Report. NREL/ TP-510-32815. National Renewable Energy Laboratory, 2002. Available at: https://www.nrel.gov/docs/fy03osti/32815.pdf (accessed 10 November 2020).

16. Devi L., Ptasinski K. J., Janssen F. J. J. G. A review of the primary measures for tar elimination in biomass gasification processes. Biomass and Bioenergy, 2003, vol. 24, iss. 2, pp. 125–140. https://doi.org/10.1016/S0961-9534(02)00102-2

17. Anis S., Zainal Z. A. Tar reduction in biomass producer gas via mechanical, catalytic and thermal methods: A review. Renewable and Sustainable Energy Reviews, 2011, vol. 15, iss. 5, pp. 2355–2377. https://doi.org/10.1016/j.rser.2011.02.018

18. Paethanom A., Nakahara S., Kobayashi M., Prawisudha P., Yoshikawa K. Performance of tar removal by absorption and adsorption for biomass gasification. Fuel Process Technology, 2012, vol. 104, pp. 144–154. https://doi.org/10.1016/j.fuproc.2012.05.006