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All Journal Jurnal Ilmiah Teknik Kimia JURNAL ILMIAH PENELITIAN MAHASISWA
Rara Ayu Lestary
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Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Economics, Econometrics & Finance Languange, Linguistic, Communication & Media Library & Information Science Medicine & Pharmacology

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Utilization of Waste Cooking Oil as Biodiesel for Portable Stoves: Comparison of Homogeneous and Heterogeneous Catalysts Sipayung, Rosmawati; Amalia, Rahma; Ra'ida Raudhatussya'rifah; Rara Ayu Lestary; Widyastuti, Nita; Mundarti, Sri; Nazarudin
JURNAL ILMIAH PENELITIAN MAHASISWA Vol 3 No 1 (2025): Februari
Publisher : Kampus Akademik Publiser

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.61722/jipm.v3i`1.734

Abstract

This research investigates the performance comparison between homogeneous (NaOH) and heterogeneous (CaO) catalyst in biodiesel production from waste cooking oil, specifically focusing on their application as fuel for portable stoves. The study examines the effects of catalyst type with NaOH concentrations of 1%, 2%, and 3%, and CaO concentrations of 4% and 6%, along with methanol-to-oil molar ratios (1:6 and 1:12) on biodiesel yield, product color, and flame characteristics. Results show that NaOH catalyst achieved higher yields (92.30%) at 3% concentration with a 1:6 methanol-to-oil ratio, while CaO catalyst reached maximum yields of 42.00% at 6% concentration with a 1:12 ratio. NaOH-catalyzed biodiesel consistently produced clear yellow coloration, whereas CaO-catalyzed biodiesel showed varying clarity depending on process conditions. In portable stove applications, NaOH-catalyzed biodiesel demonstrated superior performance with faster combustion rates (0.0607 ml/second) and blue flames, compared to CaO-catalyzed biodiesel's slower combustion (0.0412 ml/second) and yellowish-red flames.
Pemanfaatan Limbah Ampas Kopi sebagai Adsorben untuk Pengolahan Air Limbah Industri Tahu: Analisis Adsorpsi Batch dan Parameter Isoterm Rara Ayu Lestary; Oki Alfernando; Sarah Fiebrina Heraningsih; Rosmawati Sipayung; Adelia Amanda; Alya Rizki Amelia; Ita Safitri; Septrinawati Tambunan; Tiamsa Sihotang; Karisma Ulfadeli; Tiara Bartisa Putri
Jurnal Ilmiah Teknik Kimia Vol. 9 No. 2 (2025): JURNAL ILMIAH TEKNIK KIMIA
Publisher : Program Studi Teknik Kimia, Universitas Pamulang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32493/jitk.v9i2.48776

Abstract

Coffee grounds waste can be utilized as a cost-effective and eco-friendly adsorbent for treating wastewater from the tofu industry. Batch adsorption experiments were conducted to evaluate the performance of coffee grounds as an adsorbent in removing pollutants from tofu wastewater. Different adsorbent doses (1 g, 2 g, and 3 g per 200 mL) were tested, and the quality of the wastewater was assessed based on changes in Total Dissolved Solids (TDS), turbidity, conductivity, and pH. The specific adsorption capacity (mg/g) and removal efficiency (%) decreased with increasing adsorbent dose. The overall removal of contaminants was most effective at a 3 g dose, resulting in a 47% reduction in TDS and an 80% decrease in turbidity. Adsorption equilibrium data were further analyzed using Langmuir, Freundlich, and Temkin isotherm models. The Langmuir model showed the best fit (R² = 0.999), indicating monolayer adsorption on a homogeneous surface. These results demonstrate that coffee grounds waste is a promising sustainable adsorbent, particularly for small and medium-scale tofu industries with limited resources for wastewater treatment.
MODEL MATEMATIKA EKSTRAKSI COFFEE OIL DARI LIMBAH AMPAS KOPI BERDASARKAN PERBEDAAN TEMPERATUR Mega Mustikaningrum; Rara Ayu Lestary; Nita Widyastuti; Fikrah Dian Indrawati Sawali
Jurnal Ilmiah Teknik Kimia Vol. 9 No. 1 (2025): JURNAL ILMIAH TEKNIK KIMIA
Publisher : Program Studi Teknik Kimia, Universitas Pamulang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32493/jitk.v9i1.44507

Abstract

In the past decade, coffee productivity, particularly instant coffee production, has experienced significant growth. This increase has generated more coffee grounds as a by-product, which is now widely utilized in the cosmetics and energy sectors, especially for producing coffee oil. Optimization of coffee oil isolation methods continues to be developed to improve efficiency. This study aims to obtain optimal values for the coffee oil diffusivity parameter (Da) and extraction rate constant (k). Coffee grounds extraction was performed using Hexane solvent with the aid of ultrasonic waves through a bath-type sonicator. The research was conducted with variations in temperature (30°C and 40°C) and extraction time (30, 60, 90, and 120 minutes). The research results showed that the coffee oil diffusivity values at temperatures of 30°C and 40°C were 9.93 x 10⁻¹⁰ and 9.99 x 10⁻¹⁰ dm²/s, respectively. The extraction rate constants obtained at each temperature were 0.450 and 0.667 dm/s.
Transformation of Agricultural Waste into Silica–Cellulose Microsponge Adsorbent for Optimization of Waste Cooking Oil as Biodiesel Feedstock Sipayung, Rosmawati; Rahma Amalia; Rara Ayu Lestary; Nita Widyastuti; Oki Alfernando; Ira Galih Prabasari; Nazarudin; Putri Ananda; Intan Nandia Sakti
Jurnal Ilmiah Teknik Kimia Vol. 10 No. 1 (2026): JURNAL ILMIAH TEKNIK KIMIA
Publisher : Program Studi Teknik Kimia, Universitas Pamulang

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.32493/jitk.v10i1.54342

Abstract

The utilization of used cooking oil as a biodiesel feedstock is hindered by its high free fatty acid (FFA) content, which interferes with the transesterification process. This study aims to reduce FFA levels through adsorption using a silica–cellulose-based microsponge adsorbent synthesized from rice husk ash and corn cob waste. The investigated process variables include adsorbent mass (1, 3, 5 g), temperature (30, 45, 60 °C), contact time (30, 60, 90 minutes), and silica-to-cellulose ratios (40:60, 50:50, 60:40). FTIR analysis revealed characteristic peaks of Si–O–Si (~1053 cm⁻¹) and Si–O (~795 cm⁻¹) indicating the presence of amorphous silica, while the O–H stretching (~3200–3500 cm⁻¹) of cellulose appeared weaker due to silica dominance on the surface. This confirms the successful formation of the silica–cellulose composite with strong chemical interaction. Furthermore, Brunauer–Emmett–Teller (BET) analysis showed a specific surface area of 87.77 m²/g with mesoporous characteristics, confirming the microsponge structure with high affinity toward polar molecules such as FFA. The optimum conditions were obtained at 5 g adsorbent mass, 30 °C, 60 minutes contact time, and a 60:40 silica-to-cellulose ratio, achieving an FFA reduction efficiency of 49.62%. These physicochemical properties make the adsorbent efficient, energy-saving, and environmentally friendly, highlighting the great potential of agricultural waste transformation into active materials for pre-purification of used cooking oil toward sustainable biodiesel production.
Co-Authors Adelia Amanda Alya Rizki Amelia Amalia, Rahma Fikrah Dian Indrawati Sawali Intan Nandia Sakti Ira Galih Prabasari Ita Safitri Karisma Ulfadeli Mega Mustikaningrum Mundarti, Sri Nazarudin Nita Widyastuti Oki Alfernando Putri Ananda Ra'ida Raudhatussya'rifah Rahma Amalia Rosmawati Sipayung Sarah Fiebrina Heraningsih Septrinawati Tambunan Tiamsa Sihotang Tiara Bartisa Putri Widyastuti, Nita