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All Journal Jurnal Teknik Kimia dan Lingkungan Jurnal Polimesin Jurnal Solusi Masyarakat Dikara Journal of Engineering and Technological Sciences
Riskina, Shafira
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Journal : Jurnal Polimesin

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Physical and Thermal Properties of MgCl2 mixed with NaCl at Various Ratios for Solar Thermal Energy Storage Application Gunawati, Gunawati; Setiawan, Adi; Syahputri, Riana; Riskina, Shafira
Jurnal Polimesin Vol 23, No 2 (2025): April
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v23i2.6150

Abstract

Latent heat storage is a system capable of absorbing and releasing heat energy when a material undergoes a phase change. The material often used in this system is referred to as PCM (Phase Change Material). One of commonly used material for heat storage is salt. This type of material was chosen due to its low-cost and better in chemical-physical properties. This study aimed to find out the effect of combining NaCl with MgCl2 on the properties and performance of PCM. For preparation, MgCl2 was added to NaCl followed by manual mixing and grinding to ensure homogeneity. The samples were placed inside the muffle furnace and heated to 600°C. Next, the samples were evaluated for physical properties such as density, specific heat, and thermal conductivity, and tested for charging and discharging performance using a thermal box. The test results suggested that the higher MgCl2 content, the more specific heat capacity and thermal conductivity. However, it is inversely proportional to the density, where the lower the MgCl2 portion, the higher the density value. This caused the rate of thermal energy absorption and energy storage capacity increased significantly
Effect of briquetting pressure on combustion properties of hydrothermally treated king grass biomass Alchalil, Alchalil; Setiawan, Adi; Dirga, Muhammad; Riskina, Shafira; Nurjannah, Siti; Hasibuan, Rizqon; Rahman, Abdul
Jurnal Polimesin Vol 23, No 4 (2025): August
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v23i4.7300

Abstract

The utilization of biomass as an alternative energy source continues to gain attention, particularly in the form of solid briquettes with properties comparable to coal. In Indonesia, the co-firing program in coal-fired power plants (PLTU) promotes the use of biomass briquettes as supplementary fuel. King grass (Pennisetum purpureum), a fast-growing, non-food crop that thrives on marginal land, is a promising candidate. However, its low energy density limits practical application. This study aims to enhance the fuel quality of king grass through hydrothermal treatment and evaluate the effect of varying briquetting pressures on briquette properties. Briquettes were produced without pressure and with compaction pressures of 100, 200, 300, 400, and 500 kg/cm². Results show that higher briquetting pressure reduced moisture content from 3.99% to 2.98% and friability from 54.46% to 11.95%. While ash content and volatile matter were minimally affected, fixed carbon increased to 28.42%, and calorific value peaked at 3,923 kcal/kg. Hydrothermal treatment further improved calorific value, reduced ash content, and enhanced fixed carbon levels. These findings demonstrate that the combination of hydrothermal treatment and briquetting pressure significantly improves king grass briquette quality, supporting their potential as a sustainable co-firing fuel in coal-fired power plants.
Effect of torrefaction temperature and HDPE binder addition on the physicochemical and combustion properties of elephant grass bio pellets Khan, Nani Siska Putri; Setiawan, Adi; Hakim, Lukman; Hasibuan, Zulfikar; Riskina, Shafira
Jurnal Polimesin Vol 24, No 1 (2026): February
Publisher : Politeknik Negeri Lhokseumawe

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30811/jpl.v24i1.8360

Abstract

This study investigates the effect of torrefaction temperature and the addition of HDPE binder on the physical, chemical, and combustion properties of elephant grass (Pennisetum purpureum) biopellets. The samples were torrefied at 225°C and 275°C, with an HDPE plastic added at concentrations of 0, 5, 10, 15, and 20%. The results showed that higher torrefaction temperatures substantially reduced the solid yield due to the thermal decomposition of hemicellulose and cellulose, while simultaneously increasing fixed carbon and ash content. Apparent density and drop resistance showed a positive correlation with the addition of HDPE, indicating improved durability and structural integrity of the pellets. The hydrophobicity test revealed longer water penetration times with increasing HDPE content, demonstrating enhanced moisture resistance, although a slight decline was observed at 275°C due to polymer degradation. During combustion, pellets torrefied at 275°C exhibited a faster temperature rise and more stable mass reduction compared to those processed at 225°C, reflecting better combustion efficiency and heat transfer performance. The relationship between proximate analysis and combustion showed that lower Volatile Matter (VM) and higher fixed carbon contents contributed to improved thermal stability and controlled combustion behavior. These findings confirm that torrefaction at 275°C combined with a 15% HDPE binder produces high-quality biopellets with superior mechanical strength, hydrophobicity, and combustion performance, making them a promising candidate for sustainable and efficient bioenergy systems.
Co-Authors Abdul Rahman Adi Setiawan Adi Setiawan Alchalil Alchalil Dirga, Muhammad GUNAWATI, GUNAWATI Hasibuan, Zulfikar Khan, Nani Siska Putri Lukman Hakim Muhammad Muhammad Ridara, Rina Rizqon Hasibuan Setiawaty, Sri Shalihah, Nyakty Siti Nurjannah Syahputri, Riana Zainuddin Ginting