ASEAN Journal of Chemical Engineering
The ASEAN Journal of Chemical Engineering publishes papers on Chemical Engineering, specifically but not limited to the areas of thermodynamics, reaction kinetics, transport phenomena, process control, environment, energy, biotechnology, corrosion, separation science, powder technology, materials science, and chemical engineering education
Articles
372 Documents
<![CDATA[Pulping Of Vetiver Grass With NH4OH-KOH-AQ Mixtures ]]>
<![CDATA[Panitnad Chandranupap]]>;
<![CDATA[Pravitra Chandranupap]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 11, No 2 (2011) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50061
<![CDATA[The aim of this work was to study the effects of various experimental parameters on vetiver grass (Vetiveria nemoralis A. Camus) pulping. Mixtures of NH4OH-KOH were used as cooking liquors. The caustic potash did not only reduce the NH3 usage and cooking time, but also provided a potassium source as a fertilizer in the black liquor. Anthraquinone (AQ) was added in certain amount as cooking catalyst. The experiment was conducted following a central composite design involving three pulping variables (amount of KOH: 3.5 to 7% on oven-dried sample, amount of NH4OH : 25 to 45% on oven-dried sample, and cooking temperature : 145 to 160°C). The quantity of anthraquinone was fixed at 0.1% on oven-dried sample. Pulping time was fixed at 2 hours and liquid-to-oven-dried sample ratio was 8:1. Responses of pulp properties to the process variables were analyzed using DESIGN-EXPERT®, a computer-aided design of experiment software. The pulp properties revealed that this pulp is capable for making of printing and writing paper. Furthermore, this study provided a new pulping process for vetiver grass to reduce problems of discharge black liquor.]]>
<![CDATA[Adsorption Compression Analysis for Supercritical Fluids using Ono-Kondo Model ]]>
<![CDATA[Panita Sumanatrakul]]>;
<![CDATA[Chayanoot Sangwichien]]>;
<![CDATA[Gregory Aranovich]]>;
<![CDATA[Marc D Donohue]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 11, No 2 (2011) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50062
<![CDATA[In this paper, supercritical data has been evaluated and shown to demonstrate adsorption compression. Ono-Kondo analysis of adsorption isotherms for supercritical systems (including nitrogen, methane, and carbon dioxide on activated carbon Filtrasorb 400 and on zeolite 13X) indicates adsorption compression phenomenon at high pressure end just as in subcritical systems. Experimental isotherms for adsorption of supercritical fluids are plotted in Ono-Kondo coordinates with the Henry’s constant estimated based on results of modeling as well as calorimetric and chromatographic measurements. The linear sections of the results show the range of applicability of the classical Ono-Kondo model with constant energies of interactions. The slopes of these linear sections represent values and signs of these energies: negative slopes indicate repulsive interactions in adsorbed phase due to adsorption compression. Switching interactions from attractive to repulsive with an increase in the pressure for supercritical adsorption suggests that adsorbed phase has two regions. One is an attractive region at low-pressures and the other is a repulsive region at high pressures. It can be indicated that the shape of isotherms in Ono-Kondo coordinates can help to understand adsorbate-adsorbate energies; the slope of the line in Ono-Kondo coordinates gives the sign and magnitude of the energy as a function of adsorbate density.]]>
<![CDATA[Electrochemical Behaviour Of Ferrocene/Ferricinium Redox System In Pure And CO2 Saturated [C6MIM][PF6] ]]>
<![CDATA[Sebastien Chanfreau]]>;
<![CDATA[Liang-Nian He]]>;
<![CDATA[Bing Yu]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 11, No 2 (2011) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50063
<![CDATA[The electrochemical behaviour of ferrocene has been studied in green solvent combining pure ionic liquid and CO2. Experimental results were achieved for the Fc/Fc+ (ferrocene/ferricinium ion) oxidation/reduction in pure and CO2 saturated 1-hexyl-3-methylimidazolium hexafluorophosphate ([C6MIM][PF6]) over the temperature range from 298.15 K to 323.15 K. Peak shaped voltammograms were obtained and usual electrochemical parameters were calculated in order to classify electron process at the electrode. Diffusion coefficients of electroactive species were determined in the order of 10-11 m2 s-1 using the Randles–Ševcík relationship. Mass transport was also favoured by both increases in temperature and dilution of CO2 in the media.]]>
<![CDATA[Nanotitania-Activated Carbon with Enhanced Photocatalytic Activity: A Comparison Between Suspended and Immobilized Catalyst for Turquoise Blue Removal ]]>
<![CDATA[Jurex Gallo]]>;
<![CDATA[Josephine Borja]]>;
<![CDATA[Susan Gallardo]]>;
<![CDATA[Pailin Ngaotrakanwiwat]]>;
<![CDATA[Cris Salim]]>;
<![CDATA[Hirofumi Hinode]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 11, No 2 (2011) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50064
<![CDATA[The present study aims to synthesize nanoTiO2-AC and evaluate its property and photocatalytic activity using 254nm UV lamp in suspended system and as immobilized catalyst for the color removal of Turquoise blue dye solution. NanoTiO2-AC is synthesized via the sol-gel method and calcined at 400°C. Various ratio (1:10, 2:10 and 3:10) of weight AC / volume of TiO2 sol were investigated. NanoTiO2-AC is immobilized in glass plates using Polyethylene glycol (PEG) as binder. Powder and immobilized catalysts were characterized using BET, SEM-EDX, TGA, FTIR and XRD techniques. The effect of initial dye concentration, initial solution pH, catalyst loading and AC loading were investigated. SEM images confirmed the uniform distribution of nanoTiO2 attached on the surface of AC. Immobilized 1:10 AC/nanoTiO2 has lower surface area compared to powder 1:10 AC/nanoTiO2. Increasing the AC loading in AC/nanoTiO2 increases the dye adsorption in the composite catalyst to as much as 9%. The initial rate of color removal is faster in suspended catalyst compared to immobilized catalyst. In general, suspended catalyst is more efficient than immobilized catalyst. Further, PEG as a binder can be used to immobilize AC/TiO2 in glass with considerable stability.]]>
<![CDATA[DEACTIVATION OF PALLADIUM CATALYST SUPPORTED BY ALUMINA IN THE PRODUCTION OF GLYPHOSATE ]]>
<![CDATA[Edia Rahayuningsih]]>;
<![CDATA[I Made Bendiyasa]]>;
<![CDATA[Nuryono Nuryono]]>;
<![CDATA[Jupiter Jupiter]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 11, No 2 (2011) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50065
<![CDATA[During the production process of glyphosate from n-phosponomethyl iminodiacetic acid (NPMIDA) and hydrogen peroxide (H2O2 Five grams of NPMIDA, 0.3 grams of fresh palladium catalyst, and 85 mL of H), deactivation of the catalyst used may occur, which will decrease the production of glyphosate. To controll the rate of production the deactivation process of the catalyst needs to be evaluated. 2O were put into a three neck flask. One mL of H2O2 was added into the mixture every ten minutes, so that the total amount of H2O2 The activity as a function of temperature and time can be expressed as follows: added was 9 mL. The reaction was kept going for another 15 minutes. The catalyst was filtered and its filtrate collected in a 500 mL erlenmeyer glass. The filtrate was then naturally cooled to room temperature and 130 mL of technical grade ethanol was added to it. The solution was left overnight for the crystal formation. The glyphosate crystal formed was then separated from the solution and washed with 40 mL of technical grade ethanol, followed by 40 mL of technical grade ether. Finally the glyphosate crystal was dried in open air. The amount of crystal glyphosate produced was weighed and its purity was analyzed using UV/Vis spectrophotometer. The catalyst was then reused in the next experiments using the same procedure.The activity as a function of temperature and time can be expressed as follows:φ(T,t) = α t(-n) where α = 0.027T - 7.99 and (-n) = 0.005T + 1.62. These parameters hold for temperatures (T) of 333K to 363K. At 363K, the rate of deactivation of the catalyst is the fastest. Experiments that were run at 348K resulted in higher glyphosate productivity compared to other temperatures.]]>
<![CDATA[A Two-Step Fault Detection and Diagnosis Framework for Chemical Processes ]]>
<![CDATA[Lau Chee Kong]]>;
<![CDATA[Che Rosmani]]>;
<![CDATA[Che Hasan]]>;
<![CDATA[Mohd Azlan Huzzain]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 10, No 2 (2010) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50083
<![CDATA[An effective process monitoring system serves as an early warning system for influences affecting the chemical plant and helps plant operator to devise remedial actions to mitigate the adverse effects. However, the design of such system presents challenges such as complex cause-effect correlations, imprecise process model and novelty identifiability. In this work, a two-step fault detection and diagnosis framework is presented. This framework utilizes boundary models developed from mass and energy balances for each section of the chemical plant. The fault detection step consists of a fuzzy inference system (FIS) to analyze the balances and identify the faulty section if the balances deviate from the normal boundary. Then, multiple adaptive neuro-fuzzy inference system (ANFIS) classifiers are constructed to diagnose the exact root causes of bad performance. The combination of boundary models and FIS provides fault isolation of the faulty plant section even when novel faults have occurred. Utilization of multiple ANFIS classifiers reduces the complexity of the networks and improves the proficiency of the process monitoring system. The proposed scheme is applied on a model of a large scale industrial process.]]>
<![CDATA[Intermittent Hot Air, Dehumidified Air, Heat Pump and Convective Cum Vacuum Microwave Drying Characteristics and Models ]]>
<![CDATA[Chung Lim Law]]>;
<![CDATA[Chien Wha Chong]]>;
<![CDATA[Adam Figiel]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 10, No 2 (2010) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50084
<![CDATA[An intermittent hot air dehumidified air dryer, a heat pump dryer and a convective vacuum microwave dryer was designed and manufactured to dried fruits product. Fresh apple, pear, ciku, papaya and mango were chosen as raw materials. The decreased of moisture ratio with drying time were modeled using semi-empirical Page equation. This model gave excellent fit for all experimental data with coefficient of determination higher than 0.9882. In addition, drying characteristics of fruits dried using convective vacuum microwave (C/VM), cyclic temperature profile (CTP), step-up temperature profile (STP) and heat pump (HP) dryers can be obtained from the analysis of model parameters. Drying characteristics versus moisture content curve were used to verify the parameter asymptotic value. Drying characteristics exhibited by various fruit samples in this study were first falling rate periods, second falling rate periods, increasing rate periods, constant rate periods and initial transient periods depending on the application of processing and tempering. The application of convective cum vacuum microwave (C/VM) in drying of fruits gave the shortest drying time compared to other drying methods. The effective diffusivity value obtained by C/VM was between 7.08 x 10-8 to 4.30 x 10-6 m/min, which is relatively high compared to fruits dried using other drying methods (2.07x 10-8 to 5.93 x 10-8 m2/min). The results revealed that the drying time for fruits undergone C/VM drying were 50% shorter compared to samples undergone CTP, STP and HP drying. Total drying time needed was between 310 to 490 minutes for drying of selected fruits using C/VM dryer.]]>
<![CDATA[Equilibrium in the Reactive Extraction of Aqueous Phenol Using Tributyl Phospate in n-Hexane ]]>
<![CDATA[Panut Mulyono]]>;
<![CDATA[Sofiyah Sofiyah]]>;
<![CDATA[Ahmad Muhajir Kahuripan]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 10, No 2 (2010) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50085
<![CDATA[Phenol is a hazardous chemical which usually contained in the wastewater from some industries, such as oil refineries, coal processing, and plastics. Phenol is dangerous substance to a microorganism although in low concentration in wastewater. According to the United State Environmental Protection Agency, the maximum concentration of phenol in wastewater is 1 ppm. This requirement is lower than the concentration of phenol in normal wastewater discharged from industries that is 100 to 1000 ppm. Phenolic substances are very difficult to be destroyed by oxidation in the present of microorganism. Chemical oxidation of phenolic substance using ozone or combination between the ozone and UV irradiation is impossible to handle huge amount of wastewater due to the expensiveness of ozone production and also its low solubility in water. The prospective method to recover of phenol from wastewater is reactive extraction in which phenol makes a complex with the extractant. This research investigated the equilibrium of the reactive extraction of phenol from water using tributyl phosphate (TBP) in n-hexane. An equilibrium model has been developed in this research and the laboratory experiments have been carried out. The parameters of the laboratory experiment are the initial concentration of TBP in n-hexane, and the extraction temperature. The experimental results showed that the higher the TBP concentration in n-hexane, the higher the amount of phenol which can be extracted to the organic phase. The correlation between the distribution coefficients (Kc) with the ration of TBP concentration (CoTBP) to the initial TBP concentration (CoiTBP) in n-hexane can be formulated by Kc=11.59-12.002(CoTBP)/(CoiTBP) with the sum of square of error of 10.87%. The lower the extraction temperature, the higher the amount of phenol extracted to the organic phase. The correlation between the distribution coefficients with the temperature (T) can be approached by Kc=1505.45(1/T)-4.06 with the sum of square of error of 2.63%. The value of distribution coefficient of physical equilibrium (Kp) decreases with the increase of temperature, meanwhile the value of the equilibrium constant of solvation reaction (Kr) is increase with increasing the temperature. The expression of Kr as a function of temperature is Kr=-2.8636(1/T)+0.0133 with the sum of square of error of 0.04%.]]>
<![CDATA[Synthesis of Spherical Silica by Sol-Gel Method and Its Application as Catalyst Support ]]>
<![CDATA[Anirut Leksomboon]]>;
<![CDATA[Bunjerd Jongsomjit]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 10, No 2 (2010) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50086
<![CDATA[In this present study, the spherical silica support was synthesized from tetraethyloxysilane (TEOS), water, sodium hydroxide, ethylene glycol and n-dodecyltrimethyl ammonium bromide (C12TMABr). The particle size was controlled by variation of the ethylene glycol co-solvent weight ratio of a sol-gel method preparation in the range of 0.10 to 0.50. In addition, the particle size apparently increases with high weight ratio of co-solvent, but the particle size distribution was broader. The standard deviation of particle diameter is large when the co-solvent weight ratio is more than 0.35 and less than 0.15. However, the specific surface area was similar for all weight ratios ranging from 1000 to 1300 m2/g. The synthesized silica was spherical and has high specific surface area. The cobalt was impregnated onto the obtained silica to produce the cobalt catalyst used for CO2 hydrogenation.</]]>
<![CDATA[Influence of Water Content on Biofiltration Performance ]]>
<![CDATA[Daisy B Badilla]]>;
<![CDATA[Peter A Gostomski]]>;
<![CDATA[Maria Lourdes P Dalida]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 10, No 2 (2010) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50087
<![CDATA[In biofiltration, contaminants in a gas stream are transferred into a biofilm on the filter bed medium and are metabolized by the microorganisms. Water is essential for microbial growth/activity and for transport of nutrients. In both full-scale and laboratory-scale systems, the water content of the medium is difficult to control. In this study, a biofilter, with rigorous water content control and internal gas recycle, was used to determine the influence of the water content on the degradation of toluene. Soil was used as the medium for treating toluene-contaminated air at an average inlet concentration of 263 ppm and a flow rate of 21 ml min-1. Through a water retention curve, gravimetric water content was related to matric potential. Results showed that lowering the water content from 79 to 48% (dry weight) or -20 to -400 cm H2O matric potential decreased the elimination capacity (EC) by 42% (29.8 to 17.3 g m-3h-1). Wetting the medium by increasing the matric potential from -400 to -10 cm H2O increased the elimination capacity to 43.9 g m-3h-1. However, further increase of the matric potential from -10 to -5 cm H2O decreased the elimination capacity by 57% (43.9 to 19.0 g m-3 h-1). Thus, this study suggests the soil water content should be controlled at about 96% (dry weight) or a matric potential of -10 cm H2O and the maximum elimination capacity is restricted to a narrow water content/matric potential. This narrow range impacts on the operation of full-scale biofilters as traditional techniques for water content control would make maintaining this range difficult.]]>
