Influence of the specific heat capacity of the raw material fermented in a biogas reactor on the heat distribution
DOI:
https://doi.org/10.31548/energiya1(83).2026.084Keywords:
Reynolds criterion, Prandtl criterion, energy consumption, electric heating, specific heat capacity of raw materials, processing of organic wasteAbstract
Every year, the use of biogas technologies gives impetus to the development of new methods of handling accumulated waste from agricultural and household facilities. Therefore, the current issue is to reduce energy costs for maintaining the microclimate of fermentation, with the maximum possible formation of biogas from a certain type of raw material. Physico-chemical parameters have a significant impact on the fermentation of raw materials and energy costs. The purpose of the work is to analyze the impact of the specific heat capacity of the raw material fermented in a biogas reactor on the change in the Prandtl criterion and energy costs for heating. The results of theoretical studies are presented, during which the impact of the range of specific heat capacity of raw materials from 1000 to 4000 J/(kg 0C) on energy costs was analyzed The result is graphical dependences that describe the change in the heat transfer coefficient and heat transfer from the heating device to the raw material, the change in the Prandtl and Reynolds criteria depending on the change in the specific heat capacity of the raw material and the speed of rotation of the mixing device. The percentage change in the Reynolds criterion, heat transfer coefficients and heat transfer when changing the speed of rotation of the mixing device is established. It is established that the change in the Prandtl criterion depending on the change in the specific heat capacity of the raw material occurs according to a linear law. The use of the obtained results in combination with previous studies concerning the influence of physicochemical parameters on energy consumption gives an impetus towards establishing a rational speed of rotation of the mixing device from the point of view of energy consumption.
Recieved 2025-11-27
Recieved 2026-01-19
Accepted 2026-02-11
References
1. EBA. European Biogas Association: Brussels, Belgium, 2023.
2. WBA. Global Potential of Biogas; World Biogas Association: London, UK, 2019.
3. Deublein D., Steinhauser A. (2008). Biogas from Waste and Renewable Resources. An Introduction. KGaA, Weinheim.
4. Danylyshyn, V., & Koval, M. (2022). Development of alternative energy in the world and Ukraine. Machinery & Energetics, 13(2), 50-61. https://doi.org/10.31548/machenergy.13(2).2022.50-61
5. Jin C., Sun S., Yang D., Sheng W., Ma Y., He W., Li G. (2021). Anaerobic digestion: An alternative resource treatment option for food waste in China, Science of The Total Environment, 779. https://doi.org/10.1016/j.scitotenv.2021.146397
6. Z. Mykola, S. Mykhailo. (2020). Mathematical Model Of Thermal Processes During The Fermentation Of Biomass In A Biogas Reactor, 2020 IEEE KhPI Week on Advanced Technology (KhPIWeek), 227-231.
7. Spodoba, M., & Spodoba, O. (2025). Research of energy expenditures for mechanical mixing of raw materials in a biogas reactor. Electrical Engineering and Power Engineering, (2), 18–25. https://doi.org/10.15588/1607-6761-2025-2-2
8. Zablodskiy, M. M., Spodoba, M. O. (2020). Rationale for creating an electrothermomechanical system for mixing and heating biomass. Energy and Automation, 5, 136-148. http://dx.doi.org/10.31548/energiya2020.05.136
9. T. Sibiya Noxolo, E. Muzenda, H.B. Tesfagiorgis (2014). Effect of Temperature and pH on The Anaerobic Digestion of Grass Silage. Sixth International Conference on Green Technology, Renewable Energy and Environmental Engineering. Cape Town. South Africa. 198–201.
10. Rashed, M.B. (2014) The Effect of Temperature on the Biogas Production from Olive Pomace. University Bulletin, 3, 135-147.
11. M. Spodoba, O. Spodoba. (2023). Mathematical Model of Changes in Energy Costs for Thermostabilization of the Substrate and Objects in a Biogas Reactor, 2023 IEEE 5th International Conference on Modern Electrical and Energy System (MEES), Kremenchuk, Ukraine, 1-6, https://doi.org/10.1109/MEES61502.2023.10402431
12. G. Zhen, X. Lu, T. Kobayashi, Y. Li, K. Xu. (2015). Mesophilic anaerobic co-digestion of waste activated sludge and Egeria densa: Performance assessment and kinetic analysis. Appl. Energy 148, 78–86. https://doi.org/10.1016/j.apenergy.2015.03.038
13. Spodoba M.O., Spodoba О.O., Kovalchuk S.I., Oliinik Yu.O. (2025). Determination of the Energy Efficient Speed of the Working Body of the Agitator for Small Biogas Reactors. Problemele energeticii regionale, Moldova, 3. 141-152, https://doi.org/10.52254/1857-0070.2025.3-67.12
14. Spodoba M.O., Spodoba О.O. (2025). Research on the influence of the specific density of the raw material fermented in a biogas reactor on heat distribution. Energy and Automation, 4, 136-148. https://doi.org/10.31548/energiya4(80).2025.129
15. Spodoba M.O., Spodoba О.O. (2025). Research on the influence of the dynamic viscosity of raw material fermented in a biogas reactor on heat distribution. Energy and Automation, 6, 145-155. https://doi.org/10.31548/energiya6(82).2025.145
Downloads
Published
Issue
Section
License
Copyright (c) 2026 Energy and Automation
This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.
All materials are disseminated under the terms of the Creative Commons Attribution 4.0 International Public License, which permits others to distribute the manuscript with proper acknowledgement of the authorship and the original publication in this journal.
