The Pelletizability of Tea Waste and the Effect of Moisture Content and Pellet Diameter on Pellet Properties

Mehmet Akif Tanriverdi; Bahadır Demirel; Osman Mert Yaz

doi:10.47947/ijnls.1843026

The Pelletizability of Tea Waste and the Effect of Moisture Content and Pellet Diameter on Pellet Properties

Abstract

In this study, the pelletability of tea waste, a by product of tea factories, was investigated, along with the effects of different moisture contents and pellet diameters on the physical and mechanical properties of the resulting pellets. The experiments were conducted using two different moisture levels (8–9% and 11–12%) and three different pellet diameters (6, 8, and 10 mm). The findings revealed that moisture content is one of the most important parameters determining pellet quality. Pellets produced at higher moisture content (11–12%) exhibited significantly better performance in terms of mechanical strength, impact resistance, and fracture resistance under pressure compared to pellets with lower moisture content. Under low moisture conditions, pellets became more brittle, and strength losses were particularly pronounced in larger pellets. When evaluating the effects of pellet diameter, it was determined that as the diameter decreased, the mechanical integrity and strength properties of the pellets increased. Pellets with a diameter of 6 mm yielded the highest quality values, while pellets with a diameter of 10 mm exhibited weaker properties, especially under low humidity conditions. It has been confirmed that moisture content and pellet diameter have significant effects on all parameters defining pellet quality. Correlation and PCA results showed that properties such as mechanical strength, impact resistance, compressive strength, and density changed together and that high moisture–small diameter combinations were associated with higher quality pellets. It can be stated that tea waste can be converted into a high-quality pellet fuel without the use of any binder under suitable conditions, and that a moisture content of 10–12% and a diameter range of 6–8 mm are particularly favorable for tea waste pellet production. These findings point to significant potential for the energy-based utilization of tea waste in regions with intensive tea production.

Keywords

References

Bajwa, D. S., Peterson, T., Sharma, N., Shojaeiarani, J., & Bajwa, S. G. (2018). A review of densified solid biomass for energy production. Renewable and Sustainable Energy Reviews, 96, 296-305. https://doi.org/10.1016/j.rser.2018.07.040
Bilgin, S., Koçer, A., Yılmaz, H., Acar, M., & Dok, M. (2016). Çay fabrikası atıklarınının peletlenmesi ve pelet fiziksel özelliklerinin belirlenmesi. Journal of Agricultural Faculty of Gaziosmanpaşa University (JAFAG), 33 (Ek sayı), 70-80.
Cutz, L., Tiringer, U., Gilvari, H., Schott, D., Mol, A., & de Jong, W. (2021). Microstructural degradation during the storage of biomass pellets. Communications Materials, 2 (1), 2. https://doi.org/10.1038/s43246-020-00113-y
Demirel, B. (2023). Determination of solid biofuel properties of hazelnut husk briquettes obtained at different compaction pressures. Biomass Conversion and Biorefinery, 13 (14), 13267-13278. https://doi.org/10.1007/s13399-023-04431-2
Demirel, B., & Gürdil, G. (2022). Physical-Mechanical Parameters of Hazelnut Husk Bio-Briquettes Produced by a Horizontal Pressing Briquetting Machine. Black Sea Journal of Agriculture, 5 (4), 476-480. https://doi.org/10.47115/bsagriculture.1169764
Demirel, C., Gürdil, G. A. K., Kabutey, A., & Herak, D. (2020). Effects of forces, particle sizes, and moisture contents on mechanical behaviour of densified briquettes from ground sunflower stalks and hazelnut husks. Energies, 13 (10), 2542. https://doi.org/10.3390/en13102542
Dok M (2014). Karadeniz Bölgesinin tarımsal atıkpotansiyeli ve bunlardan pelet yakıt olarak yararlanılması. 4th National Workshop on Energy Agriculture and Biofuels, May 28–29, 2014, s. 211-222, Samsun.
EN 14961-2:2011, Solid biofuels — Fuel specifications and classes — Part 2: Wood pellets.

Filbakk, T., Skjevrak, G., Høibø, O., Dibdiakova, J., & Jirjis, R. (2011). The influence of storage and drying methods for Scots pine raw material on mechanical pellet properties and production parameters. Fuel Processing Technology, 92 (5), 871-878. https://doi.org/10.1016/j.fuproc.2010.12.001
Gürdil, G. (2020). Environmental impact of bio-briquettes produced from agricultural residues concerning to CO2 emissions. Mustafa Kemal Üniversitesi Tarım Bilimleri Dergisi, 25 (2), 217-224. https://doi.org/10.37908/mkutbd.735750
He, H., Wang, Y., Sun, Y., Sun, W., & Wu, K. (2024). From raw material powder to solid fuel pellet: A state-of-the-art review of biomass densification. Biomass and Bioenergy, 186, 107271. https://doi.org/10.1016/j.biombioe.2024.107271
Kaliyan, N., & Morey, R. V. (2009). Factors affecting strength and durability of densified biomass products. Biomass and bioenergy, 33 (3), 337-359. https://doi.org/10.1016/j.biombioe.2008.08.005
Kuranc, A., Stoma, M., Rydzak, L., & Pilipiuk, M. (2020). Durability Assessment of wooden pellets in relation with vibrations occurring in a logistic process of the final product. Energies, 13 (22), 5890. https://doi.org/10.3390/en13225890
Li, W., Wang, M., Meng, F., Zhang, Y., & Zhang, B. (2022). A review on the effects of pretreatment and process parameters on properties of pellets. Energies, 15 (19), 7303. https://doi.org/10.3390/en15197303
Lunguleasa, A., Olarescu, A., & Spirchez, C. (2024). Pellets obtained from the husks of sunflower seeds and beech sawdust for comparison. Forests, 15(6), 902. https://doi.org/10.3390/f15060902
Mignogna, D., Szabó, M., Ceci, P., & Avino, P. (2024). Biomass Energy and Biofuels: Perspective, Potentials, and Challenges in the Energy Transition. Sustainability, 16 (16), 7036. https://doi.org/10.3390/su16167036
Miranda, T., Montero, I., Sepúlveda, F. J., Arranz, J. I., Rojas, C. V., & Nogales, S. (2015). A review of pellets from different sources. Materials, 8 (4), 1413-1427. https://doi.org/10.3390/ma8041413
Mortadha, H., Kerrouchi, H. B., Al-Othman, A., & Tawalbeh, M. (2025). A comprehensive review of biomass pellets and their role in sustainable energy: production, properties, environment, economics, and logistics. Waste and Biomass Valorization, 16 (9), 4507-4539. https://doi.org/10.1007/s12649-024-02873-x
Mostafa, M. E., Hu, S., Wang, Y., Su, S., Hu, X., Elsayed, S. A., & Xiang, J. (2019). The significance of pelletization operating conditions: An analysis of physical and mechanical characteristics as well as energy consumption of biomass pellets. Renewable and Sustainable Energy Reviews, 105, 332-348. https://doi.org/10.1016/j.rser.2019.01.053
Picchio, R., Latterini, F., Venanzi, R., Stefanoni, W., Suardi, A., Tocci, D., & Pari, L. (2020). Pellet production from woody and non-woody feedstocks: A review on biomass quality evaluation. Energies, 13 (11), 2937. https://doi.org/10.3390/en13112937
Ribeiro, G. F., & Junior, A. B. (2023). The global energy matrix and use of agricultural residues for bioenergy production: A review with inspiring insights that aim to contribute to deliver solutions for society and industrial sectors through suggestions for future research. Waste Management & Research, 41 (8), 1283-1304. https://doi.org/10.1177/0734242X231154149
Rupasinghe, R. L., Perera, P., Bandara, R., Amarasekera, H., & Vlosky, R. (2023). Insights into properties of biomass energy pellets made from mixtures of woody and non-woody biomass: a meta-analysis. Energies, 17 (1), 54. https://doi.org/10.3390/en17010054
Sarker, T. R., Nanda, S., Meda, V., & Dalai, A. K. (2023). Densification of waste biomass for manufacturing solid biofuel pellets: a review. Environmental Chemistry Letters, 21 (1), 231-264. https://doi.org/10.1007/s10311-022-01510-0
Serrano, C., Monedero, E., Lapuerta, M., & Portero, H. (2011). Effect of moisture content, particle size and pine addition on quality parameters of barley straw pellets. Fuel Processing Technology, 92(3), 699-706. https://doi.org/10.1016/j.fuproc.2010.11.031
Stelte, W., Sanadi, A. R., Shang, L., Holm, J. K., Ahrenfeldt, J., & Henriksen, U. B. (2012). Recent developments in biomass pelletization-a review. BioResources, 7 (3), 4451-4490. https://doi.org/10.15376/biores.7.3.stelte
Svensson, A., Almarstrand, M., Axelsson, J., Nilsson, M., Timmermann, E., & Govindarajan, V. (2024). Valorising Agricultural Residues into Pellets in a Sustainable Circular Bioeconomy. Problemy Ekorozwoju, 19 (2). https://doi.org/10.35784/preko.5808
Temmerman, M., Rabier, F., Jensen, P. D., Hartmann, H., & Böhm, T. (2006). Comparative study of durability test methods for pellets and briquettes. Biomass and Bioenergy, 30 (11), 964-972. https://doi.org/10.1016/j.biombioe.2006.06.008
Thanphrom, S., Hunt, A. J., Macquarrie, D. J., & Ngernyen, Y. (2022). Valorization of green tea waste from ready-to-drink industry through pelletization and use as solid fuel. Asia-Pacific Journal of Science and Technology. https://doi.org/10.14456/apst.2022.18
Tumuluru, J. S. (2018). Effect of pellet die diameter on density and durability of pellets made from high moisture woody and herbaceous biomass. Carbon Resources Conversion, 1 (1), 44-54. https://doi.org/10.1016/j.crcon.2018.06.002
Ungureanu, N., Vladut, V., Voicu, G., Dinca, M. N., & Zabava, B. S. (2018). Influence of biomass moisture content on pellet properties–review. Engineering for Rural Development, 17, 1876-1883. https://doi.org/10.22616/ERDev2018.17.N449
Yaz, M. (2023). Adhesive wear behavior of FeB–FeMn–C coatings produced by GTAW. Materials Testing, 65 (8), 1190-1201. https://doi.org/10.1515/mt-2023-0164
Yaz, M. (2024). Adhesive wear behavior and microstructure of FeCr–FeMn–FeB–C coatings. Materials Testing, 66 (1), 75-87. https://doi.org/10.1515/mt-2023-0347
Yıldız, Z., & Topkoç, E. (2023). Tarımsal atıklardan elde edilen biyopeletlerin bazı yakıt özelliklerinin uluslararası pelet standartları ile karşılaştırılması. Artvin Çoruh Üniversitesi Orman Fakültesi Dergisi, 24 (2), 1-9. https://doi.org/10.17474/artvinofd.1231448
Yılmaz, H. (2018). Mısır saplarının peletlenmesi ve pelet özelliklerinin belirlenmesi. Mediterranean Agricultural Sciences, 31 (3), 269-274. https://doi.org/10.29136/mediterranean.427730

Details

Primary Language

English

Subjects

Agricultural Engineering (Other)

Journal Section

Research Article

Authors

Mehmet Akif Tanriverdi
0009-0001-9223-4108
Türkiye

Bahadır Demirel ^*
0000-0002-2650-1167
Türkiye

Osman Mert Yaz
0009-0003-3367-6656
Türkiye

Publication Date

December 30, 2025

Submission Date

December 16, 2025

Acceptance Date

December 21, 2025

Published in Issue

Year 2025 Volume: 9 Number: 2

DOI

https://doi.org/10.47947/ijnls.1843026

IZ

https://izlik.org/JA58LC79SS

Cite

RIS / Bibtex

APA

Tanriverdi, M. A., Demirel, B., & Yaz, O. M. (2025). The Pelletizability of Tea Waste and the Effect of Moisture Content and Pellet Diameter on Pellet Properties. International Journal of Nature and Life Sciences, 9(2), 142-155. https://doi.org/10.47947/ijnls.1843026

AMA

1.Tanriverdi MA, Demirel B, Yaz OM. The Pelletizability of Tea Waste and the Effect of Moisture Content and Pellet Diameter on Pellet Properties. Int J Nature Life Sci. 2025;9(2):142-155. doi:10.47947/ijnls.1843026

Chicago

Tanriverdi, Mehmet Akif, Bahadır Demirel, and Osman Mert Yaz. 2025. “The Pelletizability of Tea Waste and the Effect of Moisture Content and Pellet Diameter on Pellet Properties”. International Journal of Nature and Life Sciences 9 (2): 142-55. https://doi.org/10.47947/ijnls.1843026.

EndNote

Tanriverdi MA, Demirel B, Yaz OM (December 1, 2025) The Pelletizability of Tea Waste and the Effect of Moisture Content and Pellet Diameter on Pellet Properties. International Journal of Nature and Life Sciences 9 2 142–155.

IEEE

[1]M. A. Tanriverdi, B. Demirel, and O. M. Yaz, “The Pelletizability of Tea Waste and the Effect of Moisture Content and Pellet Diameter on Pellet Properties”, Int J Nature Life Sci, vol. 9, no. 2, pp. 142–155, Dec. 2025, doi: 10.47947/ijnls.1843026.

ISNAD

Tanriverdi, Mehmet Akif - Demirel, Bahadır - Yaz, Osman Mert. “The Pelletizability of Tea Waste and the Effect of Moisture Content and Pellet Diameter on Pellet Properties”. International Journal of Nature and Life Sciences 9/2 (December 1, 2025): 142-155. https://doi.org/10.47947/ijnls.1843026.

JAMA

1.Tanriverdi MA, Demirel B, Yaz OM. The Pelletizability of Tea Waste and the Effect of Moisture Content and Pellet Diameter on Pellet Properties. Int J Nature Life Sci. 2025;9:142–155.

MLA

Tanriverdi, Mehmet Akif, et al. “The Pelletizability of Tea Waste and the Effect of Moisture Content and Pellet Diameter on Pellet Properties”. International Journal of Nature and Life Sciences, vol. 9, no. 2, Dec. 2025, pp. 142-55, doi:10.47947/ijnls.1843026.

Vancouver

1.Mehmet Akif Tanriverdi, Bahadır Demirel, Osman Mert Yaz. The Pelletizability of Tea Waste and the Effect of Moisture Content and Pellet Diameter on Pellet Properties. Int J Nature Life Sci. 2025 Dec. 1;9(2):142-55. doi:10.47947/ijnls.1843026