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The Effect of Carbonization Time on The Quality Coconut Shell and Melinjo Shell Briquettes Alfiana Adhitasari; Rintis Manfaati; Yusmardhany Yusuf; Heni Anggorowati
Jurnal Bahan Alam Terbarukan Vol. 14 No. 1 (2025): June 2025 [Nationally Accredited Sinta 3]
Publisher : Universitas Negeri Semarang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.15294/jbat.v14i1.5460

Abstract

This study explores the impact of different durations of carbonization on the production of briquettes. Briquettes are produced through carbonization process conducted at different time intervals, including 30, 60, 90, 120, and 150 minutes, with a ratio composition of coconut shells and melinjo shells is 90:10. Various carbonization durations were examined to determine their influence on briquette properties, consisting of calorific value, water content, ash content, volatile matter, and density. The conclusion of this study reveals that a longer duration of carbonization results in higher values of calorific and ash content compared to shorter durations. Moreover, longer carbonization periods are associated with reductions in water content, volatile matter, and density of the briquettes. Through experimental analysis, the research indicates that the most effective duration of carbonization is 150 minutes. The briquettes produced with a 150-minute carbonization period possess a calorific value 6,004 cal/g, water content 4.65 %, ash content 4.78 %, volatile matter 6.17 %, and density 0.86 gr/cm3.
Phosphoric Acid-Activated Carbon From Coffee Grounds and Fly Ash For Efficient Laundry Wastewater Adsorption Muhari, Emma Hermawati Muhari; Silalahi, Rafael Leonardo; Puspita, Nina; Maryani, Anisya Sri; Sihombing, Rony Pasonang; Adhitasari, Alfiana; Kurnia, Dianty Rosirda Dewi
Journal of Green Science and Technology Vol 9 No 2 (2025): Journal of Green Science and Technology Vol. 9 No.2 September 2025
Publisher : Faculty of Engineering, Universitas Swadaya Gunung Jati

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33603/jgst.v9i2.10649

Abstract

Laundry waste that is directly discharged into water bodies causes pollution due to its chemical content, such as phosphate. The adsorption method is chosen as an option to reduce the phosphate content in laundry waste due to its simple preparation and low cost. The adsorbent used is a mixture of coffee grounds and fly ash. The use of coffee grounds is based on the increasing waste from coffee shops, thus being utilized as an adsorbent. The aim of this study is to determine the effectiveness of coffee grounds and fly ash with the best combination of composition and contact time using the adsorption method. The stages begin with the preparation of coffee grounds and fly ash through carbonization and activation using H3PO4. The variations performed consisted of variations in the composition of coffee grounds and fly ash with a total of 1 gram in ratios of 1:4; 2:3; 1:1; 3:2; 4:1 and contact time variations of 15 minutes, 30 minutes, 45 minutes, 60 minutes, and 75 minutes. Based on the research results, the highest percentage of removal was found in the composition variation of coffee grounds and fly ash with a ratio of 1:4 for 75 minutes.
Characterization of Coffee Business Waste in the form of Robusta Coffee Dregs as Adsorbent: A Preliminary Study Sihombing, Rony; Soeswanto, Bambang; Adhitasari, Alfiana; Yusuf, Yusmardhany; Putri, Alifhah Ananda; Fatah, Khalaida Fania; Clarisa, Shintiya; Gunawan, Sinna Chaerunnabila; Leoanggraini, Unung; Muhari, Emma Hermawati; Kurnia, Dianty Rosirda Dewi
Journal of Green Science and Technology Vol 9 No 1 (2025): Journal of Green Science and Technology Vol. 9 No. 1 March 2025
Publisher : Faculty of Engineering, Universitas Swadaya Gunung Jati

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.33603/jgst.v9i1.9104

Abstract

Robusta coffee grounds are widely produced in several types of businesses, one of which is the coffee industry (coffee shop). This pulp can be reused by business people by being used as an adsorbent and paired with the industrial waste. The purpose of this research is to identify the carbon of Robusta coffee grounds between before and after chemical activation. The methods used were sieving, drying at 25°C to 110°C, carbonization at 600°C, immersion in 0.1M HCl solution. Carbonization of Robusta coffee grounds was carried out using BET, FTIR and SEM. The results showed an increase in carbon surface area from 0.588 m2/g to 14.609 m2/g. The results of the FTIR method showed a change in functional groups on several peaks between pre- and post-activation conditions. The results of the SEM method showed an increase in pore size from 5.5 µm (before activation) to 11 µm (after activation). Keywords: Robusta coffee, Coffee grounds, FTIR, Adsorbent
The Impact of Bifunctional Catalyst Synthesis Method Cu/ZnO/ZrO2/Al2O3-HZSM-5 on Dimethyl Ether Production from CO2 and H2 Adhitasari, Alfiana; Yulistiani, Fitria; Jahulan, Tufana Muhallik; Fadhillah, Fauzan
Fluida Vol. 17 No. 1 (2024): FLUIDA
Publisher : Department of Chemical Engineering, Politeknik Negeri Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.35313/fluida.v17i1.4782

Abstract

Indonesia has initiated a zero-carbon emission plan; one strategy is to replace Liquid Petroleum Gas (LPG) with eco-friendly fuels like Dimethyl Ether (DME). However, high Operational Expenditure (OPEX) for CO2 conversion technology poses a challenge. This research aims to address these techno-economic barriers by examining how catalyst synthesis methods, specifically Ultrasonic (US) and coprecipitation (CP), impact the performance of the bifunctional catalyst Cu/ZnO/Zr/Al2O3 – H+ Zeolite Socony Mobil-5 (CZZA-HZSM-5) in DME synthesis. The catalysts are characterized using the Brunauer-Emmett-Teller (BET) method and tested in a fixed-bed reactor at 240°C and 27.6 bar, followed by a bubble reactor containing methanol. Gas Chromatography-Mass Spectrometry (GC-MS) is used for analysis. The US method produces catalysts with higher surface area, pore volume, and average pore diameter than the CP method, with values of 45.93 m²/g, 0.3822 cc/g, and 1.6646 nm, respectively. Correspondingly, the US catalyst shows higher CO2 conversion and methanol yield, at 13.3% and 59.7%. DME as the final product is undetected in GC-MS analysis, likely due to differences in HZSM5 specifications, high reaction rates, and ΔG values above 1. This study enhances understanding of how catalyst synthesis methods affect CO2 conversion efficiency, crucial for developing sustainable fuel alternatives.
A Comparative Study of Coconut Shell and Melinjo Shell as Carbon Sources for Bio-Briquette Production Augustina, Nadya; Manfaati, Rintis; Rizky, Alfiani; Yusuf, Yusmardhany; Adhitasari, Alfiana
Eksergi Vol 21 No 2 (2024)
Publisher : Prodi Teknik Kimia, Fakultas Teknik Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v21i2.10180

Abstract

The aim of this research was to investigate the influence of adding Melinjo shells on the quality and efficiency of charcoal-based bio-briquettes. A combination of coconut shells and Melinjo shells in various ratios was utilized in the study. The briquettes were produced through a carbonization process at a temperature of 300°C for 60 minutes, with tapioca flour used as a binder. Subsequently, the briquettes underwent testing to determine moisture content, ash content, volatile matter, and calorific value. The research findings indicated that all briquettes met the calorific value requirements set by the Indonesian National Standard (SNI), exceeding 5,000 cal/g. The addition of Melinjo shells resulted in a reduction in ash and volatile matter content but also led to a decrease in calorific value. Based on the analysis, the optimal composition obtained was 90 grams of coconut shells and 10 grams of Melinjo shells, producing briquettes with a calorific value of 5,582 cal/g, ash content of 3.76%, and volatile matter content of 6.65%. Therefore, further research is recommended to identify easily combustible components in Melinjo shells to ensure their potential in reducing the amount of ash produced when the briquettes are burned.
Signifikansi Kadar Kafein pada Kopi Kerinci Robusta dalam Berbagai Interval Waktu Soeswanto, Bambang; Yusuf, Yusmardhany; Sihombing, Rony Pasonang; Suryadi, Joko; Luviana, Angely; Asyari, Restu Adji Alif; Adhitasari, Alfiana
Eksergi Vol 20 No 3 (2023)
Publisher : Prodi Teknik Kimia, Fakultas Teknik Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/e.v20i3.10353

Abstract

Kopi Kerinci Robusta merupakan salah satu kopi yang digemari masyarakat Indonesia yang tumbuh di daerah Kerinci. Selama ini masyarakat hanya mengenal kopi ini untuk dinikmati saja, tanpa memperhitungkan jumlah kandungan kafein yang akan terkonsumsi. Penelitian ini bertujuan untuk mengetahui rasio terbaik pada ekstraksi kopi Kerinci Robusta menggunakan pelarut etil asetat. Rasio umpan: pelarut (b/v) yang digunakan adalah 1:5; 1:7.5; 1:10; 1:12.5. Pelarut yang digunakan dalam penelitian ini adalah etil asetat. Metode penelitian yang digunakan adalah metode ekstraksi dengan kondisi operasi 50⁰C selama 2 jam dengan interval pengambilan sampel setiap 20 menit. Kadar kafein hasil penelitian diukur dengan menggunakan spektrofotometri pada panjang gelombang 273 nm. Hasil penelitian menunjukkan bahwa rasio optimum adalah rasio 1:5 yang menghasilkan kadar kafein sebesar 3737.41 ppm.
Utilization of Coffee Grounds and Fly Ash as Adsorbents to Reduce Phosphate Content in Laundry Wastewater Yusuf, Yusmardhany; Fatah, Khalaida Fania; Gunawan, Sinna Chaerunnabila; Soeswanto, Bambang; Sihombing, Rony Pasonang; Adhitasari, Alfiana
Eksergi Vol 22 No 1 (2025)
Publisher : Prodi Teknik Kimia UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/eksergi.v22i1.12880

Abstract

Industrial laundry wastewater contains 70-80% phosphate which can cause environmental pollution and trigger the growth of algae blooms or eutrophication if it is discharged into the environment. The adsorption method was chosen to reduce the phosphate content in laundry waste because it is relatively simple and low cost. The adsorbent used can use coffee grounds and fly ash, where coffee grounds have 47.8-58.9%. The composition used for the adsorption process is a ratio of coffee grounds: fly ash (w/w) of 1:0 and 1:1. Contact time in the adsorption process varies between 30 minutes, 60 minutes, 90 minutes, 120 minutes, 150 minutes. Based on research results, the best reduction in phosphate levels from laundry waste was 45.88%, where the initial phosphate level in the waste was 10.2 mg/L. Apart from that, the efficiency of reducing COD levels with the best removal efficiency was 80.39% with the initial COD content in the waste being 4080 mg/L. The best composition for testing laundry waste is 1:1 coffee grounds and fly ash (w/w) and the best contact time for testing laundry waste is 150 minutes
Utilization of Coconut Shell and Coffee Grounds as Briquettes Using the Carbonization Method Adhitasari, Alfiana; Manfaati, Rintis; Paramitha, Tifa; Zahwa, Keisya Adellia; Setiawan, Kiranna Shalmadevy; Yusuf, Yusmardhany
Eksergi Vol 22 No 3 (2025)
Publisher : Prodi Teknik Kimia UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/eksergi.v22i3.15128

Abstract

Biomass-based briquettes offer a renewable energy alternative that can help reduce CO₂ emissions. Coconut shells and coffee grounds are promising waste materials due to their high calorific value. This study aimed to optimize the composition and carbonization time in producing briquettes from these two materials. The briquettes were prepared following SNI 01-6235-2000 and export briquette standards. The process included drying, carbonization at 300 °C for 60, 90, 120, 150, and 180 minutes, sieving, mixing, molding, and drying. Coconut shells and coffee grounds were mixed at weight ratios of 9:1, 8:2, 7:3, 6:4, and 5:5 with a total of 46.5 grams and 8.5 grams of adhesive. Briquette quality was evaluated based on moisture content, ash content, volatile matter, density, calorific value, and fixed carbon. The 9:1 composition yielded the highest calorific value of 6,472 cal/g, while a carbonization time of 90 minutes produced the best calorific value of 6,504 cal/g. The results show that a high proportion of coconut shells with limited coffee grounds and optimal carbonization time can produce briquettes with high energy potential, suitable for use as an alternative fuel.
Utilization of Natural Zeolite Impregnated with Fe for Decolorization of Methylene Blue Paramitha, Tifa; Aulia, Bunga; Azzahra, Tarisha Aulia; Taufiqurohim, Teguh; Adhitasari, Alfiana
Indonesian Journal of Chemical Research Vol 13 No 3 (2026): Edition for January 2026
Publisher : Jurusan Kimia, Fakultas Sains dan Teknologi, Universitas Pattimura

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.30598/ijcr.2026.13-tif

Abstract

Wastewater containing methylene blue, discharged into rivers, significantly impacts water quality due to its resistance to natural degradation. This study investigated the treatment of methylene blue using the photo-Fenton method, employing UV light to generate hydroxyl radicals (•OH) through the reaction of hydrogen peroxide (H₂O₂) and Fe catalyst. Natural zeolite was used as a support material, activated with NaOH solution, and impregnated with FeSO₄·7H₂O. Semi-quantitative EDS analysis indicated an iron content of 6.2 wt%. The XRD result shows that the crystalline iron phase was hematite. The photo-Fenton experiments were performed at a catalyst dosage of 0.1 g/L to degrade methylene blue with an initial concentration of 20 mg/L by varying pH levels (3, 5, 7) and H₂O₂ concentrations (15, 30, 45 mM). The optimal conditions were found to be a combination of 45 mM H₂O₂ concentration, pH 3, and under 365 nm UV lamp irradiation, achieving a maximum decolorization efficiency of 99.77% at 120 minutes. H₂O₂ concentration did not significantly affect final decolorization percentage, indicating that excess H₂O₂ does not enhance degradation beyond a certain threshold. The lowest final methylene blue concentration achieved was 0.05 mg/L, and the final chemical oxygen demand (COD) was reduced to 243.6 mg/L.
Laju Korosi Logam Baja Karbon Rendah di Larutan Garam pada Berbagai Konsentrasi Inhibitor Korosi dari Ekstrak Daun Pepaya: Low Carbon Steel Metal Corrosion Rate in Salt Solution at Various Concentrations of Corrosion Inhibitor from Papaya Leaf Extract Wahyuni, Ninik Lintang Edi; Sihombing, Rony Pasonang; Nurcahyo; Ngatin, Agustinus; Sarungu, Yunus Tonapa; Adhitasari, Alfiana; Soeswanto, Bambang; Muhari, Emma Hermawati; indarti, retno
KOVALEN: Jurnal Riset Kimia Vol. 9 No. 2 (2023): August Edition
Publisher : Chemistry Department, Mathematics and Natural Science Faculty, Tadulako University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.22487/kovalen.2023.v9.i2.16344

Abstract

Papaya leaf extract could be used as an organic corrosion inhibitor. Corrosion inhibitors were used as a method to reduce corrosion rate. The most corrosive environment was the marine environment. The purpose of this study was to determine the best concentration of papaya (Carica papaya) leaf extract inhibitor which could reduce the corrosion rate of low carbon steel in a 3.56% NaCl solution environment. The maceration process was carried out for 24 hours with 70% ethanol solvent with a solute:solvent ratio of 1:8 (w/v) at room temperature. Inhibitor extracts were analyzed qualitatively with the phytochemical method. The addition of FeCl3 was carried out on the inhibitor extract from papaya leaves. The color change occurred from blackish brown to greenish black which indicated the presence of tannin compounds in the papaya leaf extract. Corrosion testing was carried out with hot stream temperature setting at 45⁰C to 55⁰C and concentrations of inhibitor extracts at 300, 600, and 900 ppm. The test was conducted for 36 hours with a span of metal mass every 6 hours. Corrosion rate calculation is done by weight loss method. The results showed that papaya leaf extract inhibitors positive contained corrosion inhibitor and could reduce the corrosion rate in 3.56% NaCl solution. The corrosion rate without inhibitor is 1.023 mmpy. Corrosion rates with inhibitor concentrations of 300, 600, and 900 ppm were 0.755, 0.585, and 0.438 mmpy, respectively.