Jurnal Rekayasa Proses
Jurnal Rekayasa Proses is an open-access journal published by Chemical Engineering Department, Faculty of Engineering, Universitas Gadjah Mada as scientific journal to accommodate current topics related to chemical and biochemical process exploration and optimization which covers multi scale analysis from micro to macro and full plant size. Specialization topics covered by Jurnal Rekayasa Proses are: 1. Kinetics and Catalysis Includes simulations and experiments in reaction kinetics, catalyst synthesis and characterization, reactor design, process intensification, microreactor, multiphase reactors, multiscale phenomena, transfer phenomena in multiphase reactors. 2. Separation and Purification System Includes phase equilibrium, mass transfer, mixing and segregation, unit operation, distillation, absorption, extraction, membrane separation, adsorption, ion exchange, chromatography, crystallization and precipitation, supercritical fluids, bioprocess product purification. 3. Process System Engineering Includes simulation, analysis, optimization, and process control on chemical/biochemical processes based on mathematical modeling; multiscale modeling strategy (molecular level, phase level, unit level, and inter-unit integration); design of experiment (DoE); current methods on simulation for model parameter determination. 4. Oil, Gas, and Coal Technology Includes chemical engineering application on process optimization to achieve utmost efficiency in energy usage, natural gas purification, fractionation recovery, CO2 capture, coal liquefaction, enhanced oil recovery and current technology to deal with scarcity in fossil fuels and its environmental impacts. 5. Particle Technology Includes application of chemical engineering concepts on particulate system, which covers phenomenological study on nucleation, particle growth, breakage, and aggregation, particle population dynamic model, particulate fluid dynamic in chemical processes, characterization and engineering of particulate system. 6. Mineral Process Engineering Includes application of chemical engineering concepts in mineral ore processing, liberation techniques and purification, pyrometallurgy, hydrometallurgy, and energy efficiency in mineral processing industries. 7. Material and biomaterial Includes application of chemical engineering concepts in material synthesis, characterization, design and scale up of nano material synthesis, multiphase phenomena, material modifications (thin film, porous materials etc), contemporary synthesis techniques (such as chemical vapor deposition, hydrothermal synthesis, colloidal synthesis, nucleation mechanism and growth, nano particle dispersion stability, etc.). 8. Bioresource and Biomass Engineering Includes natural product processing to create higher economic value through purification and conversion techniques (such as natural dye, herbal supplements, dietary fibers, edible oils, etc), energy generation from biomass, life cycle and economic analysis on bioresource utilization. 9. Biochemistry and Bioprocess Engineering Includes biochemical reaction engineering, bioprocess optimization which includes microorganism selection and maintenance, bioprocess application for waste treatment, bioreactor modeling and optimization, downstream processing. 10. Biomedical Engineering Includes enhancement of cellular productions of enzymes, protein engineering, tissue engineering, materials for implants, and new materials to improve drug delivery system. 11. Energy, Water, Environment, and Sustainability Includes energy balances/audits in industries, energy conversion systems, energy storage and distribution system, water quality, water treatment, water quality analysis, green processes, waste minimization, environment remediation, and environment protection efforts (organic fertilizer production and application, biopesticides, etc.).
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281 Documents
<![CDATA[Analisis CFD unjuk kerja kolektor photovoltaic/thermal berdasarkan metode pendinginan permukaan atas dan bawah ]]>
<![CDATA[Nalis, Amrizal]]>;
<![CDATA[Nugraha, Yulian]]>;
<![CDATA[Irsyad, Muhammad]]>;
<![CDATA[Yonanda, Ahmad]]>;
<![CDATA[Setiawan, Ahmad Adi]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 19 No 2 (2025): Volume 19, Number 2, 2025 ]]>
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DOI: 10.22146/jrekpros.18652
<![CDATA[This research analyses the effect of radiation and fluid mass flow rate variations on the thermal performance of Photovoltaic/Thermal (PV/T) collectors based on top-surface cooling and bottom-surface cooling methods. This research uses the ANSYS Fluent simulation method based on radiation variations of 500 W/m2, 750 W/m2, 1000 W/m2, 1250 W/m2 and fluid mass flow rates of 0.02 kg/s, 0.04 kg/s, 0.06 kg/s. The research results show that cooling the top surface is proven to be more effective than cooling the bottom surface. The highest temperature difference between top and bottom cooling for PV surface temperature is 2.64 oC at a mass flow rate of 0.04 kg/s and radiation of 1250 W/m2, meanwhile, the difference in average working fluid temperature is lower than 1 oC. For a three-fold increase in fluid flow rate from 0.02 kg/s to 0.06 kg/s, the respective temperature decrease for the PV surface and working fluid is 7% and 14% respectively for both types of working fluid flow.]]>
<![CDATA[Different concentrations and solubility of active lime (CaCO3) on the quality of indigo paste from Indigofera longiracemosa Boiv.ex. Baill ]]>
<![CDATA[Muzzazinah]]>;
<![CDATA[Azmi, Hilmi Uulul]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 19 No 2 (2025): Volume 19, Number 2, 2025 ]]>
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DOI: 10.22146/jrekpros.17882
<![CDATA[This research aims to determine the effect of differences in concentration and solubility of active lime (25% and 35% CaCO3 solution, 25% and 35% CaCO3 supernatant) on the quality of indigo (Indigofera longiracemosa) dye paste. The method for making indigo dye paste includes the process of soaking fresh leaves and twigs of I. longiracemosa in water, fermentation with an active lime solution of CaCO3 with varying concentrations and solubility, settling, and filtration to obtain indigo paste. Several tests were carried out to evaluate the quality of the color in the fabric and the indican content in the indigo produced. The indican content that was successfully tested showed the highest results in the paste treated with 25% CaCO3. Color quality tests on fabrics show that fabrics dyed with indigo paste with 35% CaCO3 solution treatment have the best color fastness to sweat with an average value of 4. The color fastness test to heat on fabric dyed with indigo paste with all types of treatment received a score of 4-5, which indicates excellent color fastness, does not fade, and does not stain other fabrics. The differences in concentration and solubility of CaCO3 solution result in variations in the physical characteristics of indigo paste, the colors produced on fabric, the indican content, as well as the colorfastness to sweat and heat.]]>
<![CDATA[Pemanfaatan daun Kersen (Muntinga calabura L) dalam pewarnaan bahan tekstil yang ramah lingkungan ]]>
<![CDATA[Rosyida, Ainur]]>;
<![CDATA[Wibowo, Danur Kusuma]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 19 No 2 (2025): Volume 19, Number 2, 2025 ]]>
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DOI: 10.22146/jrekpros.16662
<![CDATA[Cherry leaves can be used as a textile dye due to their content of flavonoids and tannins that produce a yellow color on the cotton fabric. Improving dyeing results can be achieved by selecting the appropriate mordant type and mordanting method, as cherry leaves are classified as mordant dyes. This study aims to determine the effect of varying pre-mordanting times and dyeing times on the dyeing results of cotton fabric with cherry leaf extract. The dyeing process began with mordanting the fabric using Polyaluminium chloride (PAC) various times: 30, 45, 60 minutes, followed by drying. The fabric was then dyed at room temperature for varying times: 60, 90,120 minutes, followed by washing and drying. To assess dyeing quality, the fabric was tested for color strength (k/s), wash fastness, and rub fastness. Data analysis using two-way ANOVA showed that variations in pre-mordanting time and dyeing time did not significantly affect color strength, wash fastness, or rub fastness values. The dyeing results with 9 different processing conditions yielded yellow colors with varying k/s, ranging from: 4.43-5.57. The wash fastness test showed a fairly good average color change (GS: 3), and the color staining was good (SS:4-5). The dry rub fastness test showed very good average staining (SS:5), while the wet rub fastness also demonstrated good staining (SS:4-5). . The use of PAC mordant and pre-mordant methods are considered the right choice to improve dyeing results. The results indicate that cotton fabric dyed with cherry leaf extract, using pre-mordanting with PAC, without heating, and with a single dyeing process, can achieve good quality and can be applied in the textile industry/craft to produce quality and environmentally friendly products.]]>
<![CDATA[The Hydrothermally synthesized hydroxyapatite from ale-ale shells as a bone graft material alternative ]]>
<![CDATA[Tyas Galuh Amelia]]>;
<![CDATA[Maulana Irfan Edri Prasetyo]]>;
<![CDATA[Lalak Tarbiyatun Nasyin Maleiva]]>;
<![CDATA[Adhityawarman]]>;
<![CDATA[Syahrul Khairi]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 20 No 1 (2026): Volume 20, Number 1, 2026 ]]>
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DOI: 10.22146/jrekpros.20841
<![CDATA[Ale-ale shells (Meretrix meretrix), a locally abundant shellfish waste in West Kalimantan, Indonesia, were investigated as a sustainable calcium precursor for the hydrothermal synthesis of hydroxyapatite (Ca₁₀(PO₄)₆(OH)₂), the primary inorganic constituent of bone widely used in graft applications. Synthesis was conducted under varying reaction times (16–24 hours) and temperatures (140–180°C). FTIR and XRD analyses confirmed the formation of hexagonal-phase hydroxyapatite consistent with the JCPDS 09-0432 standard, with characteristic hydroxyl and phosphate functional groups detected and minor carbonate incorporation (1.00–1.52%), remaining well below the 8% limit for bone implant applications. The optimum condition was identified at 160°C for 20 hours, yielding nano-scale hydroxyapatite (14.50 nm) with high crystallinity (98.90%), satisfying ISO 13779 requirements. These findings highlight the potential of ale-ale shell-derived hydroxyapatite as a viable, locally sourced alternative to imported biomaterials while supporting the sustainable valorization of Indonesian shellfish waste.]]>
<![CDATA[Characterization of caffeine crystals obtained from the extraction process of green robusta coffee beans ]]>
<![CDATA[Tri Hariyadi]]>;
<![CDATA[Ayu Ratna Permanasari]]>;
<![CDATA[Iwan Ridwan]]>;
<![CDATA[Bambang Soeswanto]]>;
<![CDATA[Teguh Taufiqurohim]]>;
<![CDATA[Unung Leoanggraini]]>;
<![CDATA[Fania Hidayati]]>;
<![CDATA[Renata Naomi Cinta Sedjati]]>;
<![CDATA[Mentik Hulupi]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 20 No 1 (2026): Volume 20, Number 1, 2026 ]]>
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DOI: 10.22146/jrekpros.24765
<![CDATA[Robusta coffee contains a higher caffeine content, ranging from 1.6–2.4%, nearly twice as much as Arabica coffee, which contains only 0.9–1.2%. Caffeine content is widely utilized in various fields, such as pharmaceuticals and the food and beverage industry. This study aims to analyze the effect of temperature and time on the solid–liquid extraction process of green coffee beans, as well as to evaluate the effectiveness of two different solvents in the liquid–liquid extraction process for obtaining caffeine crystals. Solid–liquid extraction was carried out at temperature variations of 70°C, 80°C, 90°C, and 97°C, with durations of 30 minutes, 45 minutes, 60 minutes, 75 minutes, and 90 minutes. Liquid–liquid extraction was performed using two types of organic solvents, namely chloroform and dichloromethane. The results were analyzed by measuring caffeine purity using a melting point apparatus and high-performance liquid chromatography (HPLC) based on retention time parameters, as well as determining caffeine concentration using a UV–Vis spectrophotometer. The optimum temperature and time for solid–liquid extraction were found to be 97°C for 60 minutes. Liquid–liquid extraction yielded a caffeine content of 2.18 mg/g using chloroform, and 1.38 mg/g using dichloromethane. Based on melting point and HPLC retention time testing, the caffeine crystals obtained from liquid–liquid extraction with dichloromethane showed higher purity, with a melting point of 236°C and a retention time of 2.06 minutes. These values are close to those of pure caffeine, which has a melting point of 236°C and a retention time of 2.01 minutes, compared to the caffeine crystals obtained using chloroform.]]>
<![CDATA[Sintesis bioplastik dari pati sagu dengan penambahan selulosa limbah kertas dan plasticizer gliserol–sorbitol ]]>
<![CDATA[Wiza Ulfa Fibarzi]]>;
<![CDATA[Rizka Nurlaila]]>;
<![CDATA[Raudhatul Ulfa]]>;
<![CDATA[Yohana Dian Putri]]>;
<![CDATA[Suci Luthphia Masri]]>;
<![CDATA[Vivi Febry Katanti]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 20 No 1 (2026): Volume 20, Number 1, 2026 ]]>
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DOI: 10.22146/jrekpros.25729
<![CDATA[Bioplastics are natural-based plastics that can degrade in the environment, making them more eco- friendly. Paper waste contains cellulose with potential as a raw material for bioplastic production. This study aimed to analyze the properties of cellulose-based bioplastics derived from paper waste with the addition of sago starch and plasticizers. The manufacture of bioplastics used a variation treatment of cellulose additions of 1 gram, 2 grams, 3 grams, and without cellulose, and a plasticizer (glyserol + sorbitol) volume of 2 ml, 3 ml, 4 ml, and 5 ml. Characterization included swelling (water absorption), tensile strength, biodegradability, and thermal stability tests. Functional groups of the extracted cellulose were also examined. The extracted cellulose was characterized using FTIR and showed characteristic functional groups of cellulose, such as O–H, C–H, and C–O–C. Swelling tests showed that most bioplastic samples had values below 30 %, indicating good water resistance according to standard criteria (≤30 %). The lowest swelling was observed in samples without cellulose and with 5 mL plasticizer (15.78 %), while the highest occurred in samples with 3 g cellulose and 2 mL plasticizer (42.69 %). The best composition was obtained with 3 g cellulose and 5 mL plasticizer, giving optimal mechanical properties: tensile strength 4.08 MPa, Young’s modulus 74.85 MPa, and elongation 5.74 %. At this formulation, swelling was only 29.50 %, confirming good water resistance. Biodegradability testing also confirmed that all samples exhibited good decomposition ability in accordance with SNI 7188.7:2016 standards.Overall, the utilization of cellulose derived from paper waste combined with glycerol–sorbitol plasticizers successfully produces bioplastics with adequate mechanical properties, controlled water resistance, and high biodegradability. This formulation demonstrates strong potential as an environmentally friendly packaging material to replace conventional plastics.]]>
<![CDATA[Optimalisasi kinerja energi reaktor anaerobik biofilm skala pilot melalui pengendalian komposisi umpan limbah buah mengandung limonen ]]>
<![CDATA[Fajar Marendra]]>;
<![CDATA[Imas Dwi Dewanti Putri]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 20 No 1 (2026): Volume 20, Number 1, 2026 ]]>
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DOI: 10.22146/jrekpros.26702
<![CDATA[Fruit waste containing citrus fractions with high limonene content presents a particular challenge for anaerobic digestion (AD) due to the inhibitory effects of this terpene on methanogenic microorganisms. This study evaluates the performance of a pilot-scale biofilm anaerobic reactor treating mixed fruit waste with varying proportions of citrus residues, focusing on biogas production, methane composition, and process stability. A 1,167 L fiberglass reactor equipped with K1 biofilm carriers was operated under mesophilic conditions and fed with six different substrate formulations. The results indicate that increasing the proportion of citrus waste leads to reduced biogas production during the initial phase, accompanied by volatile fatty acid (VFA) accumulation and pH suppression, suggesting process inhibition driven by limonene. In contrast, formulations with moderated citrus content showed improved operational stability, characterized by pH values of 6.8–7.1, VFA/alkalinity ratios below 0.30, and higher methane fractions. Energy conversion analysis revealed that treatments with controlled limonene levels yielded the highest net energy output, while excessive citrus content decreased conversion efficiency. Correlation analysis confirmed strong associations between VFA accumulation, pH decline, and reduced methane concentration under high-limonene conditions. These findings demonstrate that managing the proportion of citrus-rich fruit waste is essential for maintaining process stability and enhancing biogas productivity in pilot-scale biofilm AD systems.]]>
<![CDATA[Synthesis and characterization of alkyd resin based on palm fatty acid distillate (PFAD) modified with vegetable oil ]]>
<![CDATA[Desi Nurandini]]>;
<![CDATA[Lestari Hetalesi Saputri]]>;
<![CDATA[Nopi Stiyati Prihatini]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 20 No 1 (2026): Volume 20, Number 1, 2026 ]]>
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DOI: 10.22146/jrekpros.30125
<![CDATA[Coating industry is currently in urge to produce environmentally friendly products based on considerations of maintaining ecological stability. However, the coating industry, utilizing synthetic alkyd resins, generates substantial emissions of hazardous volatile organic solvent component, while its waste presents degradation challenges. Therefore, innovations are required to coating material from renewable and eco-friendly alkyd resins. Modifying alkyd resins with natural ingredients, such as vegetable oils and fatty acids, potentially enhances their performance as coating material. This research utilizes palm fatty acid distillate (PFAD), a byproduct of palm oil (CPO) processing, as a renewable material for alkyd resin. The use of vegetable oil to modify alkyd resin improves characteristics of the product. Drying-vegetable oil solidifies and hardens through a chemical reaction in which its components cross-link and form a tough, solid film due to oxidation upon exposure to the air. This research aims to study the synthesis process of PFAD-based alkyd resin modified with vegetable oil and investigate the effect of type and composition of modified oil on the characteristics of PFAD-based alkyd resin and its performance as coating material. In this research, PFAD, glycerol, and phthalic anhydride were reacted through a one-step polyesterification process (fatty acid process) at a temperature of 240°C for 4 hours. Modification was conducted by adding vegetable oil at various compositions (a comparison was carried out using several types of drying oil including candlenut oil, linseed oil, and tung oil). The alkyd resin product was characterized by determining its acid value, iodine value, and FTIR analysis, alongside evaluating its curing performance (drying speed) in application as a coating material. The best formulation for the characteristics qualified according to the Standar Nasional Indonesia (SNI 06-0504-1989) are alkyd resins with composition of 50% weight linseed oil (AR-LO-50) and composition of 50% weight tung oil (AR-TO-50) modification, i.e. acid value of 4.6 mgKOH/g sample and iodine number of 119.20 gI₂/100 g for linseed oil, then acid value of 8.31 mgKOH/g sample and iodine number of 102.44 gI₂/100 g for tung oil. The curing test results confirmed that the modified product meets the required 1-day drying time standard.]]>
<![CDATA[Development of microwave thermochemical process using nano ZSM-5 catalyst for biogasoline production from waste cooking oil ]]>
<![CDATA[Rudi Firyanto]]>;
<![CDATA[Maria Faustina Sri Mulyaningsih]]>;
<![CDATA[Enny Purwati Nurlaili]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 0 No 0.1 (3000): ONLINE FIRST ]]>
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DOI: 10.22146/jrekpros.26985
<![CDATA[This study aims to develop a microwave-assisted thermochemical process using a nano ZSM-5 catalyst for biogasoline production from waste cooking oil (WCO). The nano ZSM-5 catalyst was characterized using XRD, BET, and SEM analyses to determine its crystalline structure, surface area, and morphology. The microwave reactor was designed to evaluate the effects of microwave power, reaction time, and catalyst-to-feed ratio on conversion efficiency and product distribution. The liquid products were analyzed by GC–MS to determine the hydrocarbon composition in the biogasoline range (C5–C12). The nano ZSM-5 catalyst exhibited high catalytic activity and selectivity toward light hydrocarbons, with a maximum WCO conversion of 92% and a biogasoline yield of 46% under optimal conditions (500 W, 15 min, 10 wt% catalyst). The microwave-assisted process demonstrated enhanced energy efficiency and faster reaction kinetics compared to conventional heating. These findings indicate that integrating microwave irradiation with nano ZSM-5 catalysis provides a promising route for sustainable biogasoline production from waste feedstocks.]]>
<![CDATA[Chlorophyll a response of Spirulina platensis to intermittent CO₂ feeding in a hybrid photobioreactor ]]>
<![CDATA[Geraldi Rahanra]]>;
<![CDATA[Awalina Satya]]>;
<![CDATA[Ika Atman Satya]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 0 No 0.1 (3000): ONLINE FIRST ]]>
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DOI: 10.22146/jrekpros.28633
<![CDATA[Chlorophyll a production during microalgae cultivation is strongly influenced by photobioreactor operating conditions. This study aimed to analyze the effects of intermittent CO₂ feeding and light intensity on chlorophyll a content of Spirulina platensis cultivated in a hybrid flat panel–bubble column photobioreactor (FCB). Cultivation was conducted at light intensities of 100, 200, and 300 µmol/(m²·s), with CO₂ concentrations of 8%, 12%, and 15% (v/v) supplied intermittently for 3 hours per day. Chlorophyll a production was evaluated based on chlorophyll a concentration and productivity. The results showed that chlorophyll a production was strongly influenced by the combined effects of CO₂ feeding concentration and light intensity applied to the culture. At irradiance levels of 100–200 µmol/(m²·s), chlorophyll a accumulation and productivity significantly increased with increasing CO₂ concentration. In contrast, at high irradiance (300 µmol/(m².s)), chlorophyll a production remained constant across all CO₂ treatments, indicating pigment saturation and that photosynthesis was mainly affected by light intensity. Chlorophyll a production increased with biomass growth, while chlorophyll a content per biomass decreased. Overall, chlorophyll a production of Spirulina platensis was strongly influenced by the interaction between intermittent CO₂ feeding concentration and light intensity.]]>
