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[Effect of MgCI2 and CaCI2 on the Bubble Point of Mixed- Solvents (Toluene-Isopropyl Alcohol-H20 System) ]]>
<![CDATA[Nathaniel P. Dugos]]>;
<![CDATA[Noel P. Cabigon]]>;
<![CDATA[Yolanda P. Brondial]]>
<![CDATA[ ASEAN Journal of Chemical Engineering vol. 6 no. 2 (2006) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50147
<![CDATA[This study investigated the effect of CaCl2 and MgCI2,both alkaline earth metal salts on the boiling points of a mixed-solvent system composed of toluene, isopropyl alcohol and water. The effect of the concentration of the salt on the boiling point of this ternary system was also examined. Results showed that mixed- solvents added with CaCl2 boil at higher temperatures than those with MgCl2even though the latter salt is higher in molal concentration. This proves that MgCI2, which has a smaller ionic radius than CaCl2 is more effective in reducing the molecular affinity to polar and associating solvents (water and isopropyl alcohol) than to the non-polar solvent (toluene). The mixed- solvent system added with MgCl2 registered higher boiling point deviation than those with CaCI2, though both showed positive deviations. Based on the results, either of the two salts can be an effective mass separating agent. However it is shown that MgCl2is better than CaCl2 because the solutions with MgCI2 generally exhibited lower boiling points. Though the difference in temperature deviations of the two salts is statistically not significant, a difference in temperature of one degree is economically significant considering the cost of energy.]]>
<![CDATA[Metal Biosorption Studies to Treat Combined Industrial Effluents Using P. chrysosporium ]]>
<![CDATA[Sripathi Rao K]]>;
<![CDATA[Ravindra P]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 6, No 1 (2006) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50148
<![CDATA[This work reports the treatability studies conducted on the combined industrial effluent sample by white rot fungus. The selected strain, Phanerochaete chrysosporium, a white rot fungus, was employed in reduction of toxic metals. The specific growth rate of the fungus was found to be in the range of 0.089-0.102 hr -1. Studies conducted on biosorption of metals showed that the dead fungal biomass was found to be more effective than living fungus. The optimum pH for the fungal growth was found to be at 4.5 but enhanced biosorption was at pH 6, especially for maximum reduction of hexavalent chromium to trivalent chromium. Laboratory-scale experiments for metal biosorption with this Basidiomycete showed encouraging results, which could be applied further to pilot tests and large-scale studies.]]>
<![CDATA[Dynamic Cycling State of Nonadiabatic Catalytic Combustion of Propylene ]]>
<![CDATA[Suryo Purwono]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 6, No 1 (2006) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50149
<![CDATA[An experimental study of nonadiabatic fixed-bed reactor for controlling propylene gas was made under flow reversal operation. Temperature measurements were made within the catalyst and packing beds. The influence of the operating parameters on the shape of temperature profiles, conversion, and heat removal were studied. The experiments showed that the maximum measured reactor temperature and heat removal were rather insensitive to changes in cycle duration and sensitive to feed flow rate and reactant concentration. The simulation results for the variation of concentration, flow rate, and cycle time showed the experimentally observed behavior Further simulations showed that runaway can occur when concentration was high.]]>
<![CDATA[Yield Study of Tea Tree Essential Oil Using Microwave-Assisted Process ]]>
<![CDATA[Amer Ali Saoud]]>;
<![CDATA[Rosli Mohd Yunus]]>;
<![CDATA[Ramlan Abd. Aziz]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 6, No 1 (2006) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50150
<![CDATA[There have been developments on the use of microwave to accelerate the digestion of solid materials, the heating of materials, and, more recently, the extraction of solute from solids via solvent as extracting medium. Microwave-assisted process (MAP) was used to accelerate the extraction of target compounds. It can be used for the extraction of compounds from various plant and animal tissues or of undesirable components from raw materials. Tea tree leaves were used in this study to investigate the applicability of microwave irradiation for essential oil extraction. The microwave parameters studied were tea tree leaves/ethanol ratio as well as required dose of microwave and time of irradiation. Different ratios of tea tree leaves/ethanol had been examined in order to obtain the optimal feed/solvent ratio that would give the highest yield of extracted essential oil. The required number of microwave doses that provided an accomplished extraction process had been ascertained. The optimal time of microwave exposure was found to be at 3 min. The measurements of extracted tea tree essential oil constituents (Le., cineole, a-pinene, and y-terpinene) that represent the major constituents were performed using gas chromatography (GC) analysis to estimate the yield of extracted tea tree essential oil.]]>
<![CDATA[Degradation of Polychlorinated Biphenyls (PCBs) in Water Matrix Using UV/H202 Efect Of Initial PCB Concentration and Analysis of Reaction Product ]]>
<![CDATA[Carmela R. Centeno]]>;
<![CDATA[Carl Renan E. Estrellan]]>;
<![CDATA[Julius B. Maridable]]>;
<![CDATA[Leonila C. Abella]]>;
<![CDATA[Susan M. Gallardo]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 6, No 1 (2006) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50151
<![CDATA[his study investigated the effect of the different initialconcentrations of polychlorinated biphenyls (PCBs) on its degradation in water matrix using UVIHP2 and on the formation of reaction intermediates or products. Simulated PCB-contaminated water solution was subjected to irradiation with 17 W, 254 nm wavelength UV lamp in a batch tubular reactor. The ratio of oxidant to PCBs, in terms of Arodor 1260, was based on 2,800 I!L HP2 isto 40 ppm PCB. Samples were extracted from the matrix by solid-phase extraction (SPE) method using C18 cartridges with hexane and ethyl acetate as solvents. The samples were analyzed using Gas Chromatography-Electron Capture Detector System (GC-ECD) to determine the concentration of PCBs in the samples and pH was monitored every sampling time. The analysis of chloride (CI-)ion concentration in the samples was done using Argentometric titration. Determination of reaction intermediates and products was carried out with 40 ppm PCB concentration using Gas Chromatography-Mass Spectroscopy (GC-MS) system. A decrease in pH in the early stages of degradation was observed and the higher the initial concentration of PCB the greater was the drop in pH. The PCB degradation profile showed that from 1 to 40 ppm initial concentration, the degradation efficiency of UVIHP2 increased with increasing initial PCB concentration. At 80 ppm, however, it was observed that there was a decrease in the efficiency of the system. The inorganic chloride ions produced indicate that dechlorination took place in the system. GC-MS analysis verified the decrease in concentration of PCBs in the solution and showed the preferential attack of the UV/HP2 to PCBs over long chain saturated alkanes or waxes which contained the PCBs.]]>
<![CDATA[Supercritical Water Oxidation for Toxic Organic Wastewater Disposal ]]>
<![CDATA[Bambang Veriansyah]]>;
<![CDATA[Benedictus Prabowo]]>;
<![CDATA[Jae-Duck Kim]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 6, No 1 (2006) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50152
<![CDATA[The destruction of toxic organic wastewaters from munitions demilitarization and complex industrial chemicals clearly becomes an overwhelming problem if left to conventional treatment processes. Two options, incineration and supercritical water oxidation (SCWO), exist for the complete destruction of toxic organic wastewaters. Incinerator, on the one hand, has associated problems such as very high cost and public resentment; SCWO, on the other hand, has proven to be a very promising method for the treatment of various types of wastewaters with its extremely efficient organic waste destruction of 99.99% with none of the emissions associated with incineration. In this review, the concepts of SCWO, the results of and present perspectives on its applications, as well as the industrial status of SCWO are critically examined and discussed.]]>
<![CDATA[Kinetics of Polychlorinated Biphenyl Biodegradation Using Biofilm Grown on Biphenyl ]]>
<![CDATA[Josephine Borja]]>;
<![CDATA[Joseph Auresenia]]>;
<![CDATA[Susan M. Gallardo]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 6, No 1 (2006) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50153
<![CDATA[The kinetics of polychlorinated biphenyl (PCB) degradation in a completely mixed three-phase fluidized-bed biofilm reactor was studied using an initial PCB concentration of 40 ppm. The mixed-culture biofilm grown on cement balls was gradually acclimatized to PCBs prior to the experimental runs. The time course of PCB concentration was monitored and the data obtained were fitted to first, second, and third order rate equations. Analysis of data was based on the assumptions that the PCB concentration was rate limiting and the mixed liquor volatile solids (MLVS) represents the active biomass. Linear regression analysis conducted for the 11 experimental runs show that PCB degradation does not follow first order kinetics. The best fit was obtained for second order in the first six runs when the overall PCB degradation was 80-85% (8-6 ppm final concentration). When the overall degradation increased to 89-92% (4-3 ppm final concentration) from run 7 onwards, the third order gave the best fit. The improved performance of the biofilm to degrade PCBs resulted in a kinetic rate pattern, which shifted from second to third order as the concentration of the PCBs dropped. The rate of PCB degradation was influenced by the presence of mixed culture whose combined attack on and long contact with PCBs resulted in PCB degradation that progressed from one batch to the next.]]>
<![CDATA[Cr(VI) Removal from Wastewater by Using Rice Husk Ash (RHA) ]]>
<![CDATA[M. J. Uddin]]>;
<![CDATA[M. M.R. Khan]]>;
<![CDATA[M S. Iftekhar]]>;
<![CDATA[M A Islam]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 6, No 1 (2006) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50154
<![CDATA[Rice husk ash (RHA) was studied as a potential adsorbent for Chromium (VI)removal from wastewater. RHA was able to remove effectively and economically toxic metal from synthetic wastewater. Experiments were done on the removal of Cr(VI) from dichromate solution which is a form of chromium in tannery effluent. The amount of Cr(VI) adsorption increased with the decrease in pH. The optimum parameter was = 2.0 evaluated at pH and the dose rate of the adsorbent was 5 kg RHNm3. The equilibrium data fit well in both the Langmuir and Freundlich isotherms. The study showed that 89.29 x 10-3kg Cr(VI) could be removed by 1 Kg of RHA. Since rice husk (RH) is available and cheap in Bangladesh, it can be used easily as an appropriate adsorbent to remove more than 95% Cr(VI) from tannery wastewater.]]>
<![CDATA[Comparison of Steady State and Dynamic Interaction Measurements in Multiloop Control Systems ]]>
<![CDATA[Renanto Handogo]]>;
<![CDATA[Avon T. H.]]>;
<![CDATA[Joko Lelono]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 5, No 1 (2005) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50158
<![CDATA[The applicability of the steady-state Relative Gain Array (RGA) to measure dynamic process interactions in a multiloop control system was investigated. Several transfer function matrices were chosen, and the gains, time constants, and dead times of their elements were varied to represent the systems with dominant dynamic interactions. It was shown that the steady-state RGA method predicted the controller pairing accurately if the pairing elements recommended by RGA had the bigger gains and the same or smaller time constants compared to other elements in the corresponding rows. When these conditions were not met, the RGA would give a wrong result, and dynamic interaction measurements, such as the Average Dynamic Gain Array (ADGA) and the Inverse Nyquist Array (lNA), should be used instead to determine the best controller pairing in a multiloop control system. Keywords: Control pairing, dynamic process interaction, multiloop control systems, Relative Gain Array (RGA), and steady state.]]>
<![CDATA[Simulation of Ethyl Tert-Butyl Ether Production from Tert-Butyl Alcohol and Ethanol in Reactive Distillation ]]>
<![CDATA[Suttichai Assabumrungrat]]>;
<![CDATA[Varong Pavarajarn]]>;
<![CDATA[Darin Wongwattanasate]]>;
<![CDATA[Piyasan Praserthdam]]>
<![CDATA[ ASEAN Journal of Chemical Engineering Vol 5, No 1 (2005) ]]>
Publisher : <![CDATA[Department of Chemical Engineering, Universitas Gadjah Mada ]]>
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DOI: 10.22146/ajche.50159
<![CDATA[Reactive distillation was applied for the synthesis of ethyl tert-butyl ether (ETBE) from a liquid-phase reaction between tert-butyl alcohol (TBA) and ethanol (EtOH) catalyzed by commercial ~-zeolite catalyst with Si/AI ratio of 55. The major side reaction of this system was the dehydration of TBA to isobutene (lB). From the present researchers' previous work, it was found that B-zeolite was superior to commercial Amberlyst-15 catalyst in reaction selectivity. The kinetic parameters for the reactions, which were determined using a semibatch reactor operated at various temperatures, were used for simulation in Aspen Plus TN program. Various operating parameters, such as heat duty, molar ratio of Hz0: EtOH, and refluxratio, were investigatedfor their effectson reactive distillation performance. Keywords: ,B-zeolite,ethyl tert-butyl ether (ETBE) synthesis, and reactive distillation.]]>
