Dinamika Teknik Mesin. I M Astika dkk.: Peningkatan konduktivitas termal lemak sapi sebagai bahan PCM dengan menambahkan arang sekam padi https://doi.org/10.29303/dtm.v11i1.364 16 Peningkatan konduktivitas termal lemak sapi sebagai bahan PCM dengan menambahkan arang sekam padi Increasing thermal conductivity of beef tallow as PCM material with the addition of rice husk char I.M. Astika*, I.N.S. Winaya, I.D.G.A. Subagia, I.K.G. Wirawan, I.G.K. Dwijana, I.G.K. Sukadana Program Studi Teknik Mesin, Fakultas Teknik, Universitas Udayana, Jl. Raya Kampus Bukit Jimbaran Badung Bali, 80361, Indonesia. HP. 08164748992. *E-mail: made_astika@unud.ac.id ARTICLE INFO ABSTRACT Article History: Received 26 June 2020 Accepted 20 January 2021 Available online 01 April 2021 Phase change material (PCM) is a material that can absorb and store energy and can release it based on the principle of latent heat energy storage. Beef tallow is one of the materials that can be used as PCM but its low thermal conductivity is around 0.181 W/mK. Hence, thermal conductivity is considered an important factor in the conduction heat transfer. This further affects kinetic absorption and heat release. However it is possible to increase the values by adding another material that has a high thermal conductivity. The purpose of this study is to elevate the thermal conductivity of beef tallow by adding rice husk char. This research involves direct incorporation method, where beef tallow is thawed and mixed with the rice husk char then stirred with a rotation of 100 rpm until the mixture becomes solid. Addition of rice husk char with weight fractions of 5 and 10% and grain size of 0.045 mm. Subsequently, thermal conductivity test was performed using the TQ Heat Transfer Experiment Base Unit.The results show that with the addition of rice husk can increase the thermal conductivity of PCM beef tallow. The increase obtained in the addition of 10% rice husk char is 37 times compared to the pure sample. Based on this result it is concluded that carbon-based materials such as rice husk char can be used to increase the thermal conductivity of PCM materials. Keywords: Beef tallow Rice husk char Thermal conductivity Dinamika Teknik Mesin, Vol. 11, No. 1 April 2021, p. ISSN: 2088-088X, e. ISSN: 2502-1729 1. PENDAHULUAN Penggunaan sumber energi yang bersumber dari bahan bakar fosil yang selama ini digunakan oleh masyarakat di seluruh dunia berdampak terhadap lingkungan seperti terjadinya perubahan iklim akibat pemanasan global (Conti dkk., 2016). Suatu alternatif untuk mengurangi dampak negatif terhadap lingkungan adalah dengan mengurangi penggunaan energi yang bersumber dari bahan bakar fosil serta meningkatkan penggunaan teknologi energi baru terbarukan yang ramah lingkungan (Bhattacharya dkk., 2016; Stram, 2016). Salah satu teknologi yang dapat menghemat penggunaan Dinamika Teknik Mesin 11(1) (2021) 16-22