Study of products derived from the microwave-assisted thermal degradation of high-moor peat

   Peat reserves are of great interest for various industries (energy, fuel, chemical, etc.). It is common practice to use pyrolysis to process such solid carbon-containing resources with the subsequent yield of fuel and valuable products. One of the environmentally and energetically favorable ways to degrade carbon-containing feedstock that is currently under development is microwave-assisted pyrolysis. Microwave radiation provides volumetric heating of the material, which significantly increases heating uniformity across the volume of the irradiated sample, providing greater efficiency of heat transfer and avoiding local overheating on the reactor surface. In the conducted study, a system was designed for the microwave processing of organic materials. The structural elements of the system are described, and a schematic showing pyrolysis product separation is presented. A prototype of the developed reactor was used to conduct experiments on degrading high-moor sphagnum peat of the Greko-Ushakovskoe deposit under mild pyrolysis conditions induced by microwave radiation. The component composition of reaction products was analyzed via chromatography-mass spectrometry and compared with the results of previous experiments using conventional thermal pyrolysis. More advanced processing of peat is performed under the conditions of microwave-assisted mild pyrolysis with a high yield of valuable products due to a more efficient heat transfer, uniform heating of the material, and the optimal reaction rate. The developed technology is shown to produce raw materials for a wide range of high-tech industrial productions. The prospects for the industrial use of the proposed microwave-assisted peat processing technology are discussed, specifically for the production of efficient hydrophobic sorbent.

1. Hakizimana J.D.K., Kim H.-T. Peat briquette as an alternative to cooking fuel: a techno-economic viability assessment in Rwanda. Energy. 2016;102:453-464. DOI: 10.1016/j.energy.2016.02.073.

2. Arpia A.A., Chen W.-H., Lam S.S., Rousset P., de Luna M.D.G. Sustainable biofuel and bioenergy production from biomass waste residues using microwave-assisted heating : a comprehensive review. Chemical Engineering Journal. 2021;403:126233. DOI: 10.1016/j.cej.2020.126233.

3. Mushtaq F., Mat R., Ani F.N. A review on microwave assisted pyrolysis of coal and biomass for fuel production. Renewable and Sustainable Energy Reviews. 2014;39:555-574. DOI: 10.1016/j.rser.2014.07.073.

4. Demirbas A., Arin G. An overview of biomass pyrolysis. Energy Sources. 2002;24(5):471-482. DOI: 10.1080/00908310252889979.

5. Berdonosov S.S. Microwave chemistry. Sorosovskii obrazovatel’nyi zhurnal. 2001;7(1):32-38. (In Russian).

6. Kuznetsov D.V., Raev V.A., Kuranov G.L., Arapov O.V., Kostikov R.R. Microwave radiation appliance for synthesis of organic substances. Zhurnal obshchei khimii. 2005;41(12):1757-1787. (In Russian). EDN: OYQPTV.

7. Mgbemena C.O., Li D., Lin M.-F., Liddel P.D., Katnam K.B., Thakur V.K., et al. Accelerated microwave curing of fibre-reinforced thermoset polymer composites for structural applications : a review of scientific challenges. Composites Part A: Applied Science and Manufacturing. 2018;115:88-103. DOI: 10.1016/j.compositesa.2018.09.012.

8. Morozov O.G., Samigullin R.R., Nasybullin A.R. Microwave technologies in processes of processing and recycling household polymeric waste. Izvestia of Samara Scientific Center of the Russian Academy of Sciences. 2010;12(4-3):580-582. (In Russian). EDN: NXJUTZ.

9. Foong S.Y., Liew R.K., Yang Y., Cheng Y.W., Yek P.N.Y., Wan Mahari W.A., et al. Valorization of biomass waste to engineered activated biochar by microwave pyrolysis: Progress, challenges, and future directions. Chemical Engineering Journal. 2020;389:124401. DOI: 10.1016/j.cej.2020.124401.

10. Patel A., Agrawal B., Rawal B.R. Pyrolysis of biomass for efficient extraction of biofuel. Energy Sources, Part A: Recovery, Utilization, and Environmental Effects. 2020;42(13):1649-1661. DOI: 10.1080/15567036.2019.1604875.

11. Fernandez A., Palacios C., Echegaray M., Mazza G., Rodriguez R. Pyrolysis and combustion of regional agro-industrial wastes: thermal behavior and kinetic parameters comparison. Combustion Science and Technology. 2018;190(1):114-135. DOI: 10.1080/00102202.2017.1377701.

12. Dupont C., Chiriac R., Gauthier G., Toche F. Heat capacity measurements of various biomass types and pyrolysis residues. Fuel. 2014;115:644-651. DOI: 10.1016/j.fuel.2013.07.086.

13. Karimi M., Aminzadehsarikhanbeglou E., Vaferi B. Robust intelligent topology for estimation of heat capacity of biochar pyrolysis residues. Measurement. 2021;183:109857. DOI: 10.1016/j.measurement.2021.109857.

14. Li F., Feng J., Zhang H., Li W.-Y. Particle-scale heat and mass transfer processes during the pyrolysis of millimeter-sized lignite particles with solid heat carriers. Applied Thermal Engineering. 2023;219:119372. DOI: 10.1016/j.applthermaleng.2022.119372.

15. Sharifzadeh M., Sadeqzadeh M., Guo M., Borhani T.N., Murthy Konda N.V.S.N., Garcia M.C., et al. The multiscale challenges of biomass fast pyrolysis and bio-oil upgrading : Review of the state of art and future research directions. Progress in Energy and Combustion Science. 2019;71:1-80. DOI: 10.1016/j.pecs.2018.10.006.

16. Papari S., Hawboldt K. A review on the pyrolysis of woody biomass to bio-oil: focus on kinetic models. Renewable and Sustainable Energy Reviews. 2015;52:1580-1595. DOI: 10.1016/j.rser.2015.07.191.

17. Kan T., Strezov V., Evans T.J. Lignocellulosic biomass pyrolysis : a review of product properties and effects of pyrolysis parameters. Renewable and Sustainable Energy Reviews. 2016;57:1126-1140. DOI: 10.1016/j.rser.2015.12.185.

18. Peskov N.Yu., Peskov N.Yu., Krapivnitskaya T.O., Sobolev D.I., Glyavin M.Yu., Denisenko A.N. Complex for microwave pyrolysis of organic materials. Patent RF, no. 2737007; 2020. (In Russian).

19. Islamova S.I., Timofeeva S.S., Khamatgalimov A.R., Ermolaev D.V. Kinetic analysis of the thermal decomposition of lowland and high-moor peats. Khimiya tverdogo topliva. 2020;3:32-41. (In Russian). DOI: 10.31857/S0023117720030044. EDN: UASEBA.

20. Krapivnitskaya T.O., Ananicheva S.A., Alyeva A.B., Vikharev A.A., Glyavin M.Yu., Denisenko A.N., et al. Comparative experiments on microwave and thermal destruction of peat in laboratory installations with a small loading volume. Elektronika i mikroelektronika SVCh. 2023;1:565-568. (In Russian). EDN: UASEBA.

21. Bogdashov A.A., Denisenko A.N., Glyavin M.Yu., Krapivnitskaia T.O., Peskov N.Yu., et al. Experimental study of the dynamics of microwave pyrolysis of peat. ITM Web of Conferences. 2019;30:12006. DOI: 10.1051/itmconf/20193012006.

22. Krapivnitskaia T.O., Bogdashov A.A., Denisenko A.N., Glyavin M.Yu., Kalynov Yu.K., Kuzikov S.V., et al. High-temperature microwave pyrolysis of peat as a method to obtaining liquid and gaseous fuels. EPJ Web of Conferences. 2017;149:02023. DOI: 10.1051/epjconf/201714902023.

23. Zhang J., Tahmasebi A., Omoriyekomwan J.E., Yu J. Production of carbon nanotubes on bio-char at low temperature via microwave-assisted CVD using Ni catalyst. Diamond and Related Materials. 2019;91:98-106. DOI: 10.1016/j.diamond.2018.11.012.