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All Journal International Journal of Advances in Applied Sciences CHEMICA Jurnal Teknik Kimia Chemistry Indonesian Journal of Chemical Research
Nirmalasari, Jiran
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Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Earth & Planetary Sciences Energy Engineering Environmental Science Materials Science & Nanotechnology Mathematics Physics

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Comparative Analysis of Coal Quality across Various Coal Basins in Sumatra: A Case Study of Calorific Value, Moisture Content, and Sulfur Content Hanum, Farrah Hanum; Hapsauqi, Iqbal; Jamilatun, Siti; Nirmalasari, Jiran
Indonesian Journal of Chemical Research Vol 12 No 1 (2024): Edition for May 2024
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2024.12-han

Abstract

Indonesia and other countries have used coal as their main energy source for many years. Due to variances in coal formation, maturity, and geological history, each basin may have a range in coal quality. It houses unique coal basins—South Sumatra, Central Sumatra, Riau, and Aceh—each marked by distinct geological features. Variations in coal formation, maturity, and geological history contribute to quality differences. The analysis of coal quality plays a crucial role in determining its suitability for various applications, including power generation, industrial processes, and export purposes. This study focuses on the coal characteristics of Riau (Coal A), Bengkulu (Coal B), South Sumatra (Coal C), and Jambi (Coal D), evaluating parameters such as calorific value, moisture content, and sulfur content. Employing ASTM-based analysis methods, results reveal that Coal D exhibits the lowest sulfur but has a diminished calorific value, while Coal A boasts a higher calorific value but the highest total sulfur content. Understanding such distinctions is crucial for determining coal's suitability for diverse applications like power generation, industrial processes, and exports. Hopefully, this research could help in estimating the economic potential of these basins, identifying areas with higher-quality coal, and planning future exploration and development activities.
Energy efficient direct transesterification of Nannochloropsis sp. using hydrodynamic cavitation Nirmalasari, Jiran; Setyawan, Martomo; Jamilatun, Siti; Pitoyo, Joko; Hakika, Dhias Cahya
International Journal of Advances in Applied Sciences Vol 14, No 2: June 2025
Publisher : Institute of Advanced Engineering and Science

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.11591/ijaas.v14.i2.pp394-405

Abstract

The increasingly limited supply of fossil fuels requires renewable fuel as an alternative source. Nannochloropsis sp. is a microalgae species containing a lipid content of between 12 and 53%, which can be converted to biofuel as an alternative source of fossil fuels through a transesterification process. Up to this date, the literature has reported no studies on biodiesel production from Nannochloropsis sp. via direct transesterification with catalyst using hydrodynamic cavitation. The direct transesterification process introduced 7.5 g of microalgae, 40 ml of methanol, 90 ml of hexane, and 0.0225 g of sodium hydroxide into the sample chamber. These mixtures were passed within the cavitation using a pressure driver and transformed into fatty acid methyl ester (FAME). The catalytic hydrodynamic cavitation method produces a higher extract yield than the stirring one. Regarding the FAME composition, the catalytic hydrodynamic cavitation method is dominated by saturated fatty acid (palmitic), while the stirring catalytic method is dominated by monounsaturated fatty acid (oleic). The hydrodynamic cavitation method provides a lower average degree of unsaturation and shorter chain length than the stirring catalytic method.
Characterisasion and Rate Determination of Lipid Extraction From Nannochloropsis Using Stirring Method Nirmalasari, Jiran; Setyawan, Martomo; Jamilatun, Siti; Suhendra, Suhendra; Othman, Mohamad Rizza
CHEMICA: Jurnal Teknik Kimia Vol. 10 No. 3 (2023): December 2023 [Available online since December 26, 2023]
Publisher : Universitas Ahmad Dahlan

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.26555/chemica.v10i3.27752

Abstract

The rapid growth of global population causes increasing energy needs. The energy needs currently used depend on fossil fuels which are non-renewable energy sources. An alternative to solve this problem is to use renewable fuel. One alternative to reduce the use of fossil fuels is microalgae. The microalgae used in this research is Nannochloropsis sp. Because it contains quite a lot of lipids, it has the potential to be used as a raw material for making biodiesel 42.315% of the fatty acids contained in Nannochloropsis are palmitoleic. This research was conducted to determine the total lipid content and percent extraction yield. The method used in this research is mixing methods. Extraction times were 30 minutes, 60 minutes, 90 minutes and 120 minutes. The greatest total lipid content was obtained at 120 m inutes with the amount obtained being 10.46%. Meanwhile, the highest percentage of results obtained was at 120 minutes, namely 10.46%. The optimum extraction speed is in the range of 0 to 30 minutes with a speed of 0.0305% with a lipid recovery of around 90% of the lipids produced.. The research results obtained showed that the extraction time affected the results obtained in terms of total lipid content and percent yield. The longer the extraction time, the greater the lipid content and percent yield obtained.
Co-Authors Dhias Cahya Hakika Hanum, Farrah Hanum Hapsauqi, Iqbal Joko Pitoyo Martomo Setyawan Othman, Mohamad Rizza Siti Jamilatun Suhendra Suhendra