Optimization of Cascara Briquettes for Renewable Energy Production through Thermoelectric Generators as an Extension of the RBL-STEM Model in Enhancing Students' Creative Thinking Skills
DOI:
10.29303/jppipa.v11i11.12919Published:
2025-12-08Downloads
Abstract
The global fossil fuel crisis and demand for sustainable renewable energy sources have driven the development of biomass-based alternative fuels. Cascara, a coffee husk by-product with high cellulose content and wide availability, has strong potential for conversion into biomass briquettes; however, improvements in fuel quality and energy conversion efficiency are needed. This study aims to improve the physical, thermal, mechanical, and emission performance of cascara briquettes by varying the composition of cascara leaves, bletong, and Tectona grandis, as well as integrating the optimized briquettes as a heat source in a thermoelectric generator (TEG) system. This study also evaluates the effectiveness of applying a STEM-based Research-Based Learning (RBL-STEM) model in improving students' creative thinking skills. This study was conducted in two stages. The experimental stage used a completely randomized design with ten briquette formulations and tested the calorific value, combustion rate, impact strength, and emissions. The learning stage applied the research results to 35 students using a single-group pretest-posttest design. The data were analyzed using instrument validation, normality tests, correlation analysis, and paired sample t-tests. The best formulation (70:20:10) produced the highest calorific value, while 50:30:20 produced the lowest emissions. The implementation of RBL-STEM significantly improved students' creative thinking performance.
Keywords:
Cascara briquettes, Creative thinking skills, RBL-STEM, Thermoelectric generatorReferences
Agatha, A. B., Dafik, & Kristiana, A. I. (2025). Development of RBL-STEM Learning to Improve Students’ Conjecturing Thinking Skills in Asymmetric Cryptography Problems in Blockchain Technology Using Super (a,d)-Hyperedge Antimagic Total Labeling of Hypergraphs. World Journal of Advanced Research and Reviews, 25(1), 1754–1763. https://doi.org/10.30574/wjarr.2025.25.1.0206
Anggono, W., Gotama, G. J., Pronk, C., Hernando, I. C., & Sutrisno, T. (2023). Characteristics of biomass briquettes from coffee husk as sustainable fuel. BIO Web of Conferences, 62. https://doi.org/10.1051/bioconf/20236203002
Aprilliani, F., Triastuti, D., & Suciati, F. (2023). Pengaruh Komposisi Ampas Kopi dan Cascara Terhadap Karakteristik Biobriket. Agroteknika, 6(2), 289–299. https://doi.org/10.55043/agroteknika.v6i2.232
Aridi, R., Faraj, J., Ali, S., Lemenand, T., & Khaled, M. (2021). Thermoelectric Power Generators: State-of-the-Art, Heat Recovery Method, and Challenges. Electricity, 2(3), 359–386. https://doi.org/10.3390/electricity2030022
Cruz, I. A., Santos Andrade, L. R., Bharagava, R. N., Nadda, A. K., Bilal, M., Figueiredo, R. T., & Romanholo Ferreira, L. F. (2021). Valorization of cassava residues for biogas production in Brazil based on the circular economy: An updated and comprehensive review. Cleaner Engineering and Technology, 4(June), 100196. https://doi.org/10.1016/j.clet.2021.100196
Dewi, R. P., Saputra, T. J., & Widodo, S. (2021). Studi Potensi Limbah Kulit Kopi Sebagai Sumber Energi Terbarukan Di Wilayah Jawa Tengah. Journal of Mechanical Engineering, 5(1). https://doi.org/10.31002/jom.v5i1.3946
Dione, N. C., Lestari, P., Susanti, D. Y., Masithoh, R. E., Azzahra, R. L., Chairani, A. M., & Rohma, A. S. D. (2025). Cellulose Extraction from Robusta Coffee Husk (Coffea canephora) as Alternative Material from Sustainable Agricultural Waste Utilization. IOP Conference Series: Earth and Environmental Science, 1438(1). https://doi.org/10.1088/1755-1315/1438/1/012073
Erdiyanto, A. S., Asshidiqi, M. H., & Syachrir, G. (2024). Bio-Briquettes Production from Spent Coffee Grounds, Composite Organic Waste, and Coconut Shells by Using Carbonization. IOP Conference Series: Earth and Environmental Science, 1395(1). https://doi.org/10.1088/1755-1315/1395/1/012010
Fansyuri, M., Nurkholis, -, Mikhratunnisa, -, Rizaldi, L. H., & Ariskanopitasari, -. (2023). Karakteristik briket ampas tebu (bagasse) dari bahan perekat tepung beras ketan. Jurnal Agrotek Ummat, 10(1), 1. https://doi.org/10.31764/jau.v10i1.12266
Fitriyano, G., Ismiyati, I., Purnawan, I., & Ramadhan, R. F. (2023). Production and Characterization of Bio-Briquettes from Coconut Leaves and Cassava Peels. International Journal of Applied Sciences and Smart Technologies, 5(2), 1–12. https://doi.org/10.24071/ijasst.v5i2.5567
Gibran, M. A., Novianto, S., Supriyadi, S., & Bhikuning, A. (2024). Termoelektrik Generator Dan Fungsinya. Jurnal Penelitian Dan Karya Ilmiah Lembaga Penelitian Universitas Trisakti, 9, 404–418. https://doi.org/10.25105/pdk.v9i2.20109
Gita, R. S. D., Waluyo, J., Dafik, & Indrawati. (2023). The Analysis of the Implementation of RBL-STEM in Improving Students Creative Thinking Skills in Solving the Use of Chitosan as an Antibacterial for Processed Meat. European Journal of Education and Pedagogy, 4(2), 36–47. https://doi.org/10.24018/ejedu.2023.4.2.524
Hakim, L., Iswanto, A. H., Lubis, Y. S., Wirawan, A. J., Batubara, R., Kim, N. H., Antov, P., Rogoziński, T., Hua, L. S., Chen, L. W., Selvasembian, R., Jayusman, & Sutiawan, J. (2025). Charcoal Briquette Manufactured from Indonesian Sugar Palm Bunches (Arenga longipes Mogea) as Biomass-Based New Renewable Energy. Journal of Renewable Materials, 13(3), 639–652. https://doi.org/10.32604/jrm.2025.056365
Jouhara, H., Żabnieńska-Góra, A., Khordehgah, N., Doraghi, Q., Ahmad, L., Norman, L., Axcell, B., Wrobel, L., & Dai, S. (2021). Thermoelectric generator (TEG) technologies and applications. International Journal of Thermofluids, 9. https://doi.org/10.1016/j.ijft.2021.100063
Joy, L. M., Henrich N, G. Y., Nimfa A, J. N., Mae B, P., & Louis G, L. B. (2024). From Waste to Sustainable Energy: Harnessing Organic By-Products in Developing Eco-Briquettes. International Journal of Advanced Multidisciplinary Research and Studies, 4(6), 977–980. https://doi.org/10.62225/2583049x.2024.4.6.3539
Junior, O. H. A., Silva, E. A. da, Lira, E. R. de, Degiorgi, S. V. B., & Carmo, J. P. P. do. (2024). Comparative Analysis and Integrated Methodology for the Electrical Design and Performance Evaluation of Thermoelectric Generators (TEGs) in Energy Harvesting Applications. Energies, 17(20). https://doi.org/10.3390/en17205176
Khalil, R. Y., Tairab, H., Qablan, A., Alarabi, K., & Mansour, Y. (2023). STEM-Based Curriculum and Creative Thinking in High School Students. Education Sciences, 13(12). https://doi.org/10.3390/educsci13121195
Komaria, N., Suratno, Prihatin, J., & Sudarti. (2020). An analysis of innovation on the utilization of cascara by coffee farmers. Journal of Physics: Conference Series, 1563(1). https://doi.org/10.1088/1742-6596/1563/1/012015
Lubwama, M., Yiga, V. A., Muhairwe, F., & Kihedu, J. (2020). Physical and combustion properties of agricultural residue bio-char bio-composite briquettes as sustainable domestic energy sources. Renewable Energy, 148, 1002–1016. https://doi.org/10.1016/j.renene.2019.10.085
Maulidian, O., Wahyuni, P. N., Pujiastuti, C., Widodo, L. U., & Edahwati, L. (2022). Kajian Peningkatan Nilai Kalor Briket Blotong Dengan Penambahan Pelepah Pisang Dan Molase. Jurnal Teknik Kimia, 16(2), 101–106. https://doi.org/10.33005/jurnal_tekkim.v16i2.3052
Mustafa, S., & Ibrahim, S. (2023). Thermal and Physical Properties of Briquette Fuels from Coconut Shells and Cocoa Shells. Bioresources and Environment, 1(3), 45–53. https://doi.org/10.24191/bioenv.v1i3.39
Patil, G. (2019). The possibility study of briquetting agricultural wastes for alternative energy. Indonesian Journal of Forestry Research, 6(2), 133–139. https://doi.org/10.20886/IJFR.2019.6.2.133-139
Pratama, A. T., Nuryanto, A., Setiadi, B. R., Rosyadi, S., Limiansi, K., & Kusumawardani, N. (2023). Alternative fuels from recycling dried leaves of Tectona grandis into briquettes. AIP Conference Proceedings, 2671(March). https://doi.org/10.1063/5.0116493
Pratiwi, A. F. R., & Rosdiana, L. (2025). Implementasi Inkuiri Terbimbing Melalui Pendekatan Stem Untuk Meningkatkan Keterampilan Berpikir Kritis. BIOCHEPHY: Journal of Science Education, 5(1), 71–77. https://doi.org/10.52562/biochephy.v5i1.1439
Qi, J., & Wu, J. (2023). Effects of Bio-Coal Briquette for Residential Combustion on Brown Carbon Emission Reduction. Processes, 11(6). https://doi.org/10.3390/pr11061834
Rashif, M. N., Hartini, S., Sari, D. P., Ramadan, B. S., Matsumoto, T., & Balasbaneh, A. T. (2025). Life cycle assessment of biomass waste briquettes as renewable energy. Global Journal of Environmental Science and Management, 11(1), 207–224. https://doi.org/10.22034/gjesm.2025.01.13
Ritli, A. El, & Adlini, M. N. (2022). The effect of guided inquiry learning model on students’ critical thinking skills in biology learning. BIO-INOVED : Jurnal Biologi-Inovasi Pendidikan, 4(3), 241. https://doi.org/10.20527/bino.v4i3.13841
Saba, S., El Bachawati, M., & Malek, M. (2020). Cradle to grave Life Cycle Assessment of Lebanese biomass briquettes. Journal of Cleaner Production, 253, 119851. https://doi.org/10.1016/j.jclepro.2019.119851
Sanjayanti, A., Alamsyah, M., & Fadhillah, M. (2025). Implementasi Research-Based Learning Untuk Mengoptimalkan Research Skills Mahasiswa. Jurnal Penelitian Nusantara, 1, 500–508. https://doi.org/10.59435/menulis.v1i8.616
Susanto, Kristiana, A. I., Dafik, Fatahillah, A., Venkatachalam, M., & Tanna, D. (2025). Enhancing Students’ Conjecturing Skills Through RBL-STEM with Antimagic Coloring and Geometric Transformation in Batik Design. Emerging Science Journal, 9(2), 868–889. https://doi.org/10.28991/ESJ-2025-09-02-019
Tesfaye, A., Workie, F., & Kumar, V. S. (2022). Production and Characterization of Coffee Husk Fuel Briquettes as an Alternative Energy Source. Advances in Materials Science and Engineering, 2022. https://doi.org/10.1155/2022/9139766
US EIA. (2025). Monthly Energy Review. Retrieved from www.eia.gov/mer
Van Toan, N., Kim Tuoi, T. T., & Ono, T. (2022). High-performance flexible thermoelectric generator for self-powered wireless BLE sensing systems. Journal of Power Sources, 536. https://doi.org/10.1016/j.jpowsour.2022.231504
Wulandari, Y. N., Kristiana, A. I., & Dafik. (2025). The development of RBL-STEM learning tools to improve students’ computational thinking skills in solving plant disease classification problems using convolutional neural network segmentation. World Journal of Advanced Research and Reviews, 25(1), 804–812. https://doi.org/10.30574/wjarr.2025.25.1.0086
License
Copyright (c) 2025 Nurul Komaria, Nostalgianti Citra Prystiananta
This work is licensed under a Creative Commons Attribution 4.0 International License.
Authors who publish with Jurnal Penelitian Pendidikan IPA, agree to the following terms:
- Authors retain copyright and grant the journal right of first publication with the work simultaneously licensed under a Creative Commons Attribution 4.0 International License (CC-BY License). This license allows authors to use all articles, data sets, graphics, and appendices in data mining applications, search engines, web sites, blogs, and other platforms by providing an appropriate reference. The journal allows the author(s) to hold the copyright without restrictions and will retain publishing rights without restrictions.
- Authors are able to enter into separate, additional contractual arrangements for the non-exclusive distribution of the journal's published version of the work (e.g., post it to an institutional repository or publish it in a book), with an acknowledgment of its initial publication in Jurnal Penelitian Pendidikan IPA.
- Authors are permitted and encouraged to post their work online (e.g., in institutional repositories or on their website) prior to and during the submission process, as it can lead to productive exchanges, as well as earlier and greater citation of published work (See The Effect of Open Access).
