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Contact Name
Muhamad Maulana Azimatun Nur
Contact Email
lanaazim@upnyk.ac.id
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Journal Mail Official
editor.eksergi@gmail.com
Editorial Address
Prodi Teknik Kimia UPN Veteran Yogyakarta"</span>. Jl. SWK. 104 Lingkar Utara Condong Catur- Yogyakarta (55283)
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Kab. sleman,
Daerah istimewa yogyakarta
INDONESIA
Eksergi: Chemical Engineering Journal
ISSN : 1410394X     EISSN : 24608203     DOI : https://doi.org/10.31315
Eksergi is an open-access, peer-reviewed scientific journal that focuses on research and innovation in the fields of energy and renewable energy. The journal aims to provide a platform for scientists, researchers, engineers, and practitioners to share knowledge and advancements that contribute to sustainable development and energy transition. In addition to energy topics, the journal also accepts high-quality manuscripts related to, but not limited to, the following areas: Separation processes Bioprocesses related to food, energy, and environmental applications Wastewater treatment and resource recovery Process optimization and intensification Carbon capture, utilization, and storage (CCUS) Chemical reaction engineering and reactor design Life cycle assessment (LCA) and sustainability evaluation Process Design and Control Engineering Process Simulations Process System Engineering The journal welcomes original research articles, reviews, and short communications that demonstrate novelty, scientific rigor, and relevance to chemical engineering and interdisciplinary applications.
Articles 11 Documents
Search results for , issue "Vol 22 No 2 (2025)" : 11 Documents clear
The Effect of Ammonium Sulfate Concentrations on The Size Distributions of NPK-Fertilizer Granules in a Rotating Drum Granulator Hardhianti, Meiga Putri Wahyu; Sebastian, Ivan; Wiratni
Eksergi Vol 22 No 2 (2025)
Publisher : Prodi Teknik Kimia, Fakultas Teknik Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/eksergi.v22i2.14256

Abstract

The granulation process is important in pharmaceuticals, detergents, and fertilizers. It consists of enlarging the particle size to create granules with specific properties. This study examined the wet granulation process for NPK fertilizers and investigated the effect of binder solutions, particularly ammonium sulfate (ZA) concentrations, on the distribution of granule sizes. The granulation process was conducted in a rotating drum granulator with varied NPK ratios (28-6-6, 20-20-8, 18-16-20, and 15-15-15) with amounts of binder (10 ml or 20 ml of 15% ZA solution or pure water). Granule sizes were analyzed using Image Pro Plus software, and Stoke’s number was calculated to establish a correlation between the average granule radius and Stoke’s number. The results showed that ammonium sulfate improved granulation, leading to larger granule size and more consistent size distribution in various NPK formulations than water-bond granules. Furthermore, a higher liquid-to-solid ratio generally increases granule size, resulting in a broader size distribution. The study demonstrated a robust correlation (R² = 0.95) between Stoke's number and the average granule radius, indicating that Stoke's number served as a generalized parameter of the granulation process for various NPK formulations and binder types.
Combination Process of Rice Husk Ash Coagulation and Electrocoagulation for Palm Oil Mill Effluent Treatment Lestari, Indriana; Amalia, Dwi; Prastistho, Widyawanto; Angin, Jeremia Bernadin Perangin; Zenatik, Muhammad Haekal
Eksergi Vol 22 No 2 (2025)
Publisher : Prodi Teknik Kimia, Fakultas Teknik Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/eksergi.v22i2.14305

Abstract

Palm oil mill effluent (POME) poses a significant environmental threat due to its high organic and inorganic load. This study introduces a novel integration of rice husk ash (RHA) coagulation and electrocoagulation (EC) for sustainable POME remediation. Thermally treated at 500 °C for two hours, RHA was characterized via FTIR, revealing active silica-based functional groups conducive to charge neutralization and adsorption. Treatment experiments employed 9.3 g/L RHA and aluminum electrodes spaced 20 mm apart under varying currents of 10, 15, and 20 A over 15, 30, and 45 minutes. At the highest tested condition (9.3 g/L RHA, 20 A, 45 minutes), the integrated process achieved 78% total solids (TS) and 43% chemical oxygen demand (COD) removal, surpassing individual RHA coagulation removed 34% TS and 17% COD, while EC alone achieved 43% TS and 18% COD removal. The superior performance stems from synergistic flocculation, adsorption, and electroflotation. Compared to conventional methods, the combined RHA–EC system offers faster treatment, lower chemical and energy demands, and improved sustainability. These findings suggest a scalable solution for decentralized POME treatment, particularly in resource-limited palm oil-producing regions.
Modelling Urea and Creatinine Concentration Distribution in Hollow Fiber Membranes for Hemodialysis Applications Fauziah, Melinda Nur; Nurkhamidah, Siti; Taufany, Fadlilatul; Altway, Ali; Susianto; Rahmawati, Yeni
Eksergi Vol 22 No 2 (2025)
Publisher : Prodi Teknik Kimia, Fakultas Teknik Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/eksergi.v22i2.14515

Abstract

Humans are dynamic creatures who continue to follow developments over time. This development also has a big impact on changes in habits and has an impact on the health of everyone, which needs special attention in this era of globalization. One of the treatments for kidney failure patients is kidney function replacement therapy, namely haemodialysis. Haemodialysis therapy is a high technology to replace the function of the kidneys in removing metabolic waste (air, sodium, potassium, hydrogen, urea, creatinine, uric acid and other substances) through a semi-permeable membrane as a separator for blood and dialysate fluid in an artificial kidney (dialyzer). where the processes of diffusion, osmosis, and ultrafiltration occur. In this study, a hollow fiber type dialyzer was used which consisting of three main components: the shell (which directs dialysate flow), the porous membrane, and the tube (which carries blood). In general, this research will be carried out theoretically by developing a mathematical model of mass transfer in hollow fiber membranes in the haemodialysis process to study the distribution of urea and creatinine concentrations in the tube, membrane, and shell axial and radial section, the effect of pore area of membrane on urea and creatinine clearance, and the influence of dialysate flowrate on urea and creatinine clearance. The mathematical modeling successfully illustrates the distribution of urea and creatinine concentrations within the hollow fiber membrane both axially and radially, with a concentration decrease from blood to dialysate, influenced by diffusion and convection mechanisms. Simulation results indicate that increasing dialysate flowrate enhances haemodialysis efficiency, but its effect diminishes after reaching a certain threshold. Meanwhile, increasing the membrane surface area from 1.3 m² to 1.8 m² results in only a slight reduction in the urea concentration from 16.67 mol/m³ to 16.62 mol/m³ and creatinine from 8.85 mol/m³ to 8.83 mol/m³, demonstrating that membrane surface area has a smaller impact.
Fabrication and Characterization of Psf-TiO2/GO Membranes for Photocatalytic Decomposition of Dyes in Batik Liquid Waste Arofah, Rosyida Nofiana; Rahmawat, Yeni; Taufany, Fadlilatul; Nurkhamidah, Siti
Eksergi Vol 22 No 2 (2025)
Publisher : Prodi Teknik Kimia, Fakultas Teknik Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/eksergi.v22i2.14654

Abstract

One of the important processes in making batik cloth is dyeing which requires large amounts of water. Liquid waste from washing and rinsing batik cloth produces color from residual dye and can be the main source of water pollution. One method of removing dyes is the ultrafiltration process using Membrane Technology for photocatalytic decomposition. In this research, polysulfone (PSf) membrane uses addition of different TiO2 compositions (1, 1.5, 2, 3, and 5 wt.%) and graphene oxide (GO) of 0.5 wt.% composition as photocatalyst. The photocatalyst can store energy therefore the photocatalytic process can be performed in a visible light environment. To identify the best composition of photocatalysts, photocatalytic performances were tested by the removal of methyl violet as dye along with characterization of the membranes for the morphological and physicochemical properties using FTIR, SEM, XRD, and DMA. The highest performance under visible light was shown by a membrane containing 5 wt.% TiO2, which provided a permeate flux of 22.97 L m-2 h-1 and dye removal of up to 89.84%. The findings indicated that the PSf membrane matrix's stability and photocatalytic enhanced potential are driven by the cooperative interaction between TiO2 and GO nanoparticles, which function as photocatalysts.
Production of Healthy Sugar by Adding Winter Melon [Benincasa hipsida (Thunb.) Cogn.] From Coconut Sap Megasari, Gabrilla Ulfa; Fahmi; Nurkhamidah, Siti
Eksergi Vol 22 No 2 (2025)
Publisher : Prodi Teknik Kimia, Fakultas Teknik Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/eksergi.v22i2.14656

Abstract

The increasing prevalence of health issues such as diabetes, obesity, and hypertension due to excessive sugar consumption has prompted the need for healthier sugar alternatives. This study investigates the production of healthy sugar using coconut sap enriched with winter melon (Benincasa hispida) extract, which offers various health benefits, including anti-diabetic properties. The production process employed a vacuum rotary evaporator at controlled temperatures (50–80°C) to preserve the nutritional and physical qualities of the sugar while minimizing adverse effects of traditional methods. The study assessed sugar composition, crystallization behavior, and product yield. Results showed that the addition of winter melon extract enhanced antioxidant properties and functional value, while varying sugar seed concentrations improved crystallization, yield (up to 10.48%), and color stability. This research contributes to developing low-glycemic, nutritious sugar alternatives, meeting the increasing demand for healthier sweeteners.
Enhancing Biodiesel Yield from Castor Seed Oil through Co-Solvent-Assisted Transesterification Using n-Hexane Yasyifa, Annisa; Atin, Ro; Istiani, Alit; Anggorowati, Heni
Eksergi Vol 22 No 2 (2025)
Publisher : Prodi Teknik Kimia, Fakultas Teknik Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/eksergi.v22i2.14658

Abstract

The growing demand for sustainable energy sources has increased interest in biodiesel as a renewable alternative to petroleum-based fuels. This study explored the effect of reaction time, molar ratio of methanol to oil, and catalyst concentration with the addition of co-solvent on the transesterification of castor seed oil, aiming to increase methyl ester yield. n-Hexane was chosen as the co-solvent due to its physical compatibility with methanol, thus facilitating reactant solubility and product separation. Using response surface methodology (RSM) with Minitab software, process parameters such as co-solvent ratio, reaction duration, and temperature were optimized. The optimized conditions (1:5 co-solvent ratio, 55°C, 20 min) resulted in a biodiesel yield of 98.86%, with GC-MS confirming a methyl ester content of 99.79%. The resulting biodiesel yield met the requirements of the Indonesian National Standard (SNI) as well as viscosity but had a heating value that was slightly below the standard range. These findings highlight the effectiveness of co-solvent integration in improving biodiesel production from vegetable oil feedstocks.
Enhancing Fuel Oil from Polyethylene Waste: A Comparative Study of Catalyst Efficiency in Thermal Pyrolysis Dhaniswara, Trisna Kumala; Juliasti, Sri Rachmania; Mahfud, Mahfud
Eksergi Vol 22 No 2 (2025)
Publisher : Prodi Teknik Kimia, Fakultas Teknik Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/eksergi.v22i2.14780

Abstract

The growing accumulation of polyethylene (PE) plastic waste poses a significant environmental challenge, necessitating effective recycling and waste management solutions. Thermal pyrolysis has emerged as a promising method for converting plastic waste into valuable hydrocarbons. This study presents a comparative analysis of catalyst efficiency in the thermal pyrolysis of PE waste, with a focus on maximizing product yield and optimizing chemical composition. Various catalysts were evaluated to assess their impact on the degradation process, product distribution, and overall conversion efficiency. The research utilized 100 grams of PE waste in the form of 2 cm pellets. The catalysts tested—activated carbon, HZSM-5, and low-rank coal (LRC)—were each added at 10% of the plastic's weight. The experiments were conducted under varying conditions of time (30, 60, 90, 120, 150, and 180 minutes) and temperature (350, 450, 550, and 650°C). The thermal pyrolysis setup included an integrated furnace with glass column fractionation and four trays for collecting liquid pyrolysis products. Key parameters such as total yield, °API and calorific value were analyzed and compared to those of conventional fuel oil. The results demonstrated that the LRC catalyst outperformed both activated carbon and HZSM-5, achieving a yield of 61.10% at 650°C for 180 minutes. The pyrolysis product obtained using the LRC catalyst exhibited properties—such as °API and calorific value—comparable to those of conventional gasoline. This study highlights the potential of catalytic pyrolysis in managing plastic waste effectively, offering a viable approach to reducing plastic pollution while producing valuable hydrocarbon products. The findings underscore the importance of catalyst selection in optimizing pyrolysis outcomes, providing valuable insights for sustainable plastic waste management
Green Extraction of Microcrystalline Cellulose from Cabbage Waste (Brassica Oleracea L.) via Steam Explosion Under Pressurized and Non-Pressurized Nitrogen (N2) Syafira, Nesha Permata; Airlangga, Bramantyo; Sumarno
Eksergi Vol 22 No 2 (2025)
Publisher : Prodi Teknik Kimia, Fakultas Teknik Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/eksergi.v22i2.14826

Abstract

Agricultural residues such as cabbage waste (Brassica oleracea L.) are rich in cellulose and offer promising potential for sustainable microcrystalline cellulose (MCC) production. This study aims to extract and characterize MCC from cabbage waste using an environmentally friendly approach that combines high-speed blending, low-concentration oxalic acid hydrolysis (0–2% w/v), and steam explosion at 130 °C for 15 minutes, under both pressurized and non-pressurized nitrogen (N₂) atmospheres. The application of pressurized N₂ significantly improved delignification efficiency and preserved cellulose crystallinity. The optimal treatment (2% oxalic acid with N₂) yielded a cellulose content of 79.18%, with hemicellulose and lignin contents reduced to 15.28% and 0.10%, respectively. FTIR analysis confirmed the effective removal of non-cellulosic components, while XRD analysis revealed a crystallinity index 66%, which is high compared to typical MCC values from other biowastes (~50–60%). SEM revealed clean and well-dispersed fiber morphology. These results indicate that oxalic acid combined with N₂-assisted steam explosion is an effective and eco-friendly method for producing MCC. This approach minimizes chemical use and oxidation, making it suitable for pharmaceutical excipients, biodegradable composites, and other green material applications. Overall, the process aligns with circular economy principles and contributes to the Sustainable Development Goals (SDGs).
A Critical Review of Carbonization Hydrothermal and Pyrolysis for Adsorbent Production and the Application in Industrial Dye Removal Nyamiati, Retno Dwi; Putri Restu Dewati; Muhammad Redo Ramadhan; Ika Wahyuning Widiarti; A Hidayat Nurwahid; Nabila Aulia Balqis
Eksergi Vol 22 No 2 (2025)
Publisher : Prodi Teknik Kimia, Fakultas Teknik Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/eksergi.v22i2.14742

Abstract

Biochar is increasingly recognised as a low-cost and efficient adsorbent for removing organic dyes from wastewater. This review outlines recent developments in biochar production, particularly comparing biochars produced via pyrolysis and hydrothermal carbonisation (HTC). While pyrolysis biochar often exhibits a higher surface area, HTC biochar offers improved oxygen-containing functional groups, contributing to enhanced dye affinity. Studies indicate that biochar can achieve adsorption capacities ranging from 2 to 1353.09 mg/g for dyes such as methylene blue and crystal violet, comparable to or exceeding that of pyrolysis-derived biochars. The review also highlights characterisation techniques such as XRD, FTIR spectroscopy, and SEM to evaluate surface functionality, porosity, and morphology, which directly influence adsorption performance. Practical implications include the suitability of HTC biochar for low-energy, decentralised wastewater treatment systems, particularly in textile and dyeing industries. By connecting production parameters with biochar properties, this review provides insights into optimizing biochar as an adsorbent, particularly for the treatment of dye-contaminated wastewater.
Comparative Analysis of CO₂ Content in Biogas and Synthetic Gas Using Chittick Titration Validated by Gas Chromatography Pambudi, Alfian Wisnu; Rahmawati, Yeni; Taufany, Fadlilatul; Altway, Ali; Susianto
Eksergi Vol 22 No 2 (2025)
Publisher : Prodi Teknik Kimia, Fakultas Teknik Industri, UPN "Veteran" Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.31315/eksergi.v22i2.14809

Abstract

This study aimed to validate the Chittick titration method for measuring carbon dioxide (CO2) content using gas chromatography (GC) as the reference method. Two types of gas samples were analyzed: synthetic CO2/N2 gas with a theoretical composition of 40:60 and biogas produced by anaerobic fermentation. Analyses were conducted in parallel using both methods to compare CO2 measurements. For synthetic gas, the Chittick titration recorded an average CO2 content of 39.11%, whereas GC recorded 40.52%. For biogas, Chittick titration produced 30.16%, whereas GC measured 31.40%. The differences between the methods were 0.81% for synthetic gas and 1.55% for biogas, with relative errors of 2.00% and 3.45%, respectively. The t-test results showed statistically significant differences (p < 0.05) between the methods for both gas types. However, the observed deviations remained within practically acceptable limits for small-scale laboratory applications. These findings suggest that Chittick titration is a practical and cost-effective alternative for estimating CO2 content, particularly in laboratories with limited access to gas chromatography equipment. This study is expected to serve as a useful reference for educational institutions and small laboratories that are seeking to develop simple gas analysis methods with adequate validity.

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