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.).
Articles
276 Documents
<![CDATA[Kesetimbangan natrium di dalam campuran biodiesel gliserol ]]>
<![CDATA[Supriyono Supriyono]]>;
<![CDATA[Kurnia Wijayanti]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 2 No 1 (2008): Volume 2, Nomor 1, 2008 ]]>
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DOI: 10.22146/jrekpros.547
<![CDATA[Transesterification is one of the processes for producing biodiesel. The process involves the use of liquid catalyst such as NaOH. However, the presence of Na+ ions in biodiesel accelerates the scale formation and aggravates the combustion engine performance. Therefore, the maximum concentration of Na+ is about 5 mg / kg biodiesel to minimize the effect. Recently, the focus study of transesterification using NaOH as a catalyst is achieving higher conversion. Meanwhile, the reduction process of Na+ remaining in the biodiesel has not yet been studied. The experiments were carried out in a three-neck flask equipped with a reflux condenser where jatropha oil was reacted with methanol. The amount of methanol was 3 times of the stoichiometric molar ratio, while NaOH was used as catalyst. The concentration of Na+ both in the glycerol and biodiesel phases were analyzed. Based on the excess Gibbs free energy, the maximum concentration of NaOH for transesterification of Jatropha oil was 0.0015% weight.]]>
<![CDATA[Pengaruh konsentrasi katalisator dan rasio bahan terhadap kualitas biodiesel dari minyak kelapa ]]>
<![CDATA[Erna Astuti]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 2 No 1 (2008): Volume 2, Nomor 1, 2008 ]]>
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DOI: 10.22146/jrekpros.548
<![CDATA[The demand for energy in Indonesia has increased very fast in the recent years in the midst of fossil oil depletion. A lot of effort has been carried out to find alternative energies. One of the promising alternative energies is biodiesel. Indonesia, as the largest producer of vegetable oil in the world, has an opportunity to play a significant role as a biodiesel producer. Among various vegetable oils, coconut oil is a potential raw material in biodiesel production. The process was carried out in a three-neck round bottom flask equipped with motor stirrer and thermometer. The trans-esterification reaction was conducted by mixing heated coconut oil with a mixture of ethanol and KOH catalyst for two hours. The process variables studied in the present work were catalyst concentration and coconut oil – ethanol ratio. At the optimal condition when the KOH concentration in a range of 0.75-0.90% w/v and a coconut oil – ethanol ratio of 3:1 -5:1, the process produce biodiesel that meets the standard.]]>
<![CDATA[Pengaruh konsentrasi dan jenis larutan perendaman terhadap kecepatan ekstraksi dan sifat gel agar-agar dari rumput laut Gracilaria verrucosa ]]>
<![CDATA[Sperisa Distantina]]>;
<![CDATA[Devinta Rachmawati Anggraeni]]>;
<![CDATA[Lidya Eka Fitri]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 2 No 1 (2008): Volume 2, Nomor 1, 2008 ]]>
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DOI: 10.22146/jrekpros.549
<![CDATA[Seaweeds of Gracilaria species are abundantly cultivated in Indonesia. However, studies related to its extractionprocess are still rare. In the present work, the mass transfer process on a batch extraction of agar was studied byextracting seaweeds in hot water solvent. The effect of alkali (NaOH) and acetic acid (CH3COOH) in the soakingprocess on the volumetric mass transfer coefficient (kca) and the quality of gel agar were investigated.Seaweeds (Gracilaria verrucosa) from Pekalongan coast were soaked in aqueous NaOH (1.5 N and 3.75 N) or inaqueous acetic acid solution (0.2 N, 0.6 N, and 0.8 N). After being washed, the seaweeds were extracted in hotwater of 980C and neutral pH. Some of the extract samples at various times were freezed, thawed, dried andweighed. The evaluation of experimental data showed that the mass transfer coefficient kca decreased and the gelstrength of agar increased with the increase of alkali concentration. Meanwhile, the value of kca increased andthe gel strength of agar decreased with the increase of acetic acid concentration.]]>
<![CDATA[Konstanta laju pengeringan daun sambiloto menggunakan pengering tekanan rendah ]]>
<![CDATA[Sri Rahayoe]]>;
<![CDATA[Budi Rahardjo]]>;
<![CDATA[Rr. Siti Kusumandari]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 2 No 1 (2008): Volume 2, Nomor 1, 2008 ]]>
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DOI: 10.22146/jrekpros.550
<![CDATA[Herbs (traditional medicine) such as sambiloto leaves are senisitive to heat, therefore the drying process of herbs were performed at low-pressure. At low pressure, evaporation of water in the herbs can be carried out at a temperature below 100°C. The low temperature of drying may reduce the destruction of heat-sensitive chemicals inside the herbs. The present study aimed at analyzing the drying rate constant of sambiloto leaves during lowpressure drying. Sambiloto leaves were dried at varied temperature of 30°C, 40°C, and 50°C, and varied pressure of 61 kPa, 48 kPa, and 35 kPa. The water content of sambiloto leaves was reduced from ± 70% to ± 10%. The change in water content was measured after 10, 20, 30, 60, 90, 120, 150 and 210 minutes, by using thermogravimetry technique. The drying-rate constant was calculated using the equation of thin films. The drying-rate constant was 0.01 – 0.0175 min-1. It was observed that the drying-rate increases as the pressure decreases. To predict the change of water content in sambiloto leaves during low-pressure drying process, an empirical equation for the drying-rate constant as a function of temperature and pressure was derived from theexperimental data, kprediction= 0,00075T0,823P-0,021.]]>
<![CDATA[Studi kinerja katalisator lewatit monoplus s-100 pada reaksi esterifikasi antara etanol dan asam asetat ]]>
<![CDATA[Nuryoto Nuryoto]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 2 No 1 (2008): Volume 2, Nomor 1, 2008 ]]>
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DOI: 10.22146/jrekpros.551
<![CDATA[Sulfuric acid is common catalyst in producing ethyl acetate. Despite of high conversion, using sulfuric acid as catalyst is appearing a lot of problems. The use of solid catalyst is expected to solve the problem. Utilizing of lewatit monoplus s-100 in the esterification of ethanol and acetic acid was investigated in this work. The experiments were carried out in a reactor on the hot plate equipped with magnetic stirrer. The reactant ratio was 1.2 gmol acetic acid / gmol ethanol and lewatit monoplus s-100 as catalyst. Samples were taken at initial and after 60 minutes, then the samples were analyzed by using gas chromatograph. The same experiments were conducted at different temperatures and catalyst concentrations. Based on the experimental result, lewatit monoplus s-100 performed well as solid catalyst in the esterification. It was shown that the higher the temperature, the higher the reaction rate, meanwhile increasing the catalyst concentration, the conversion was lower. The highest conversion was 87.3%, when the temperature was 358 K, and a catalyst concentration was 0.8 g. resin /g. ethanol.]]>
<![CDATA[Pemanfaatan zeolit alam klinoptilolite sebagai katalisator dalam alkoholisis minyak jarak ]]>
<![CDATA[Ratna Sri Harjanti]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 2 No 1 (2008): Volume 2, Nomor 1, 2008 ]]>
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DOI: 10.22146/jrekpros.552
<![CDATA[The use of solid catalyst in alcoholysis can increase the purity of ester because the separation process of solid catalyst is simpler than that of liquid catalyst. Prior to the ester formation, the ethanol was activated by the zeolite, forming alkoxide molecules. These molecules can attack the carbonyl functional group at the triglyceride in Jatropha oil and form ester. Jatropha oil, ethanol, and clinoptilolite zeolite powder were added into an autoclave equipped with manometer, thermometer, sampling valve, and heater. The autoclave was then powered up and rotated, and sampling was performed at time interval of 10 minutes. The reaction was performed at a temperature of 120°C and an autoclave rotation speed 110 rpm, with varied catalyst percentage and ethanol-oil equivalent ratio. The conversion was determined by analyzing the glycerol concentration of the lower layer with acetyl method. This study confirms that clinoptilolite type zeolite is effective catalyst for alcoholysis of jatropha oil. When the ethanol-oil ratio was 12.55 mgek/mgek, the catalyst percentage was 2.56% weight, the glyceride conversion reached 73%.]]>
<![CDATA[Upaya peningkatan efisiensi energi di Pupuk Kujang ]]>
<![CDATA[Maryono Maryono]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 2 No 2 (2008): Volume 2, Number 2, 2008 ]]>
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DOI: 10.22146/jrekpros.553
<![CDATA[ACES21 is an urea manufacturing process technology which is the latest process of Toyo Engineering Corp. (TEC) with some advantages compared with previous technologies. ACES21 is designed with low investment cost and low energy consumption. Compared with the previous process some improvements have been done such as urea reactor that in the previous process was installed at a height of 20-22 meters above the ground, on ACES21 urea reactor was installed at ground level so that it can reduce construction costs. The synthesis process conditions where the urea formation reaction occurs is operated at relatively lower pressure than before that eventually reduces energy consumption. In addition to the ease and reliability of the operation, the urea plant has several on-line monitoring equipment that has not been widely applied such as nitrogen/carbon ratio monitoring, leak detector monitoring, and analyzer monitoring (ACES21, On-line Monitoring, ground Level). With the operation of Kujang IB that already uses ACES21 process, the energy consumption which in the previous process (Kujang 1A) was originally 8.324 Gcal/tonne of urea is reduced to 5.623 Gcal/tonne of urea, resulting in a significant energy saving.]]>
<![CDATA[Sifat-sifat penyalaan dan pembakaran briket biomassa, briket batubara dan arang kayu ]]>
<![CDATA[Siti Jamilatun]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 2 No 2 (2008): Volume 2, Number 2, 2008 ]]>
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DOI: 10.22146/jrekpros.554
<![CDATA[In general, combustion of solid material consists of several steps including heating, drying, de-volatilization and burning of the charcoal. The factors that determine combustion characteristics of briquettes are the rate of combustion, heating value, density and amount of pollutants or volatile compounds produced. The present work aimed at determining combustion characteristics of various kinds of briquettes from biomass, wood charcoal and coal including the rate of combustion, duration of briquettes burn to ashes, the initial ignition, amount of smoke or volatile compounds produced, heating value and duration for boiling one liter of water. The experimental work was performed by burning 250 grams of each briquette. The results showed that coconut shell had the longest combustion duration (116 minutes) with a combustion rate of 126.6 grams/second. In comparison with other biomass briquettes and wood choarcoal, coconut shell had the highest heating values of 5,779.11 cal/gram which was close to heating value of coal briquette (6,058 cal/gram). All briquettes studied in the present work showed a reasonable duration and needed about 5 – 7 minutes to boil one litter of water.]]>
<![CDATA[Pemodelan matematis reaksi oksidasi katalitik fero sulfat menjadi feri sulfat ]]>
<![CDATA[Takdir Syarif]]>;
<![CDATA[Andiyan Yuwono]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 2 No 2 (2008): Volume 2, Number 2, 2008 ]]>
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DOI: 10.22146/jrekpros.555
<![CDATA[Iron was dissolved in a sulfuric acid to form a concentrated ferrous sulphate (FeSO4) solution. This research was conducted to form ferric sulfate by catalytic oxidation of ferrous sulfate using manganese dioxide as catalyst. The system was a three-phase heterogeneous reaction with a quite complex kinetics The present study aimed at developing a mathematical modeling of three-phase reaction kinetics that involved gas, liquid and solid. Oxidation was undertaken in an isothermal isobaric condition in a three-neck flask reactor. The experiment was conducted in a temperature range of 323 to 353 K with a catalyst concentration of 1.7 g/L. The results indicated that the reaction kinetics could be approached with a quasi steady state model and the chemical reaction on the catalyst surface was the determining step.]]>
<![CDATA[Hidrolisis minyak biji kapuk dengan katalisator asam khlorida ]]>
<![CDATA[Ganjar Andaka]]>
<![CDATA[ Jurnal Rekayasa Proses Vol 2 No 2 (2008): Volume 2, Number 2, 2008 ]]>
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DOI: 10.22146/jrekpros.556
<![CDATA[Hydrolysis of kapok seed oil in the presence of hydrochloric acid catalyst to produce glycerol and fatty acid was studied. The objective of this work was to study the effect of reaction temperature and catalyst concentration on the reaction rate constant. The experiments were conducted in a three-neck flask equiped with stirrer, heater, condenser, and thermometer. The reaction condition studied were temperature ranging from 80 to 100 °C and catalyst concentration from 0.011 to 0.017 N. The reaction time was kept constant at 3 hours. The concentration of triglycerides every 0.25 hour were analyzed to calculate the conversion of triglycerides. The results of this study showed that the reaction kinetics of the hydrolysis of kapok seed oil was found to be first order with respect to triglyceride. The effect of reaction temperatures on the reaction rate constant was found to be k = 0.3258 exp(−1379.8875/RT) h−1, the activation energy was 1379.8875 cal/mol and the effect of catalyst concentrations on the reaction rate constant could be expressed as k = 0.06002 exp(−0.0025/Ck) h−1.]]>
