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ASEAN Journal of Chemical Engineering

AJChE
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Published by Universitas Gadjah Mada

ISSN : 26555409 EISSN : 26555409 DOI : https://doi.org/10.22146/ajche.52004

Core Subject : Science, Engineering,

Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry

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

Arjuna Subject : Teknik Kimia (semua kategori) - Kimia Proses dan Teknologi

Articles 8 Documents

Search results for , issue "Vol 11, No 2 (2011)" : 8 Documents clear

Modeling of the Drying Kinetics of Slurry Droplet in Spray Drying Boris Golman
ASEAN Journal of Chemical Engineering Vol 11, No 2 (2011)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

The detail analysis of the heat and mass transfer between the droplet containing suspended solids and the drying gas was carried out numerically. The temperature and moisture distributions within the slurry droplet were calculated during the first and second drying phases. The parametric study revealed that the droplet drying time decreases with increasing the drying gas temperature and decreasing the droplet diameter.

Numerical Simulation of Air Flow and Temperature Distribution in Yarn Drying Room Jindarat Pimsamarn; Panit Kitsubun; Rabin Tongruk
ASEAN Journal of Chemical Engineering Vol 11, No 2 (2011)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

This research studied the recovery of wasted heat from exhaust air releasing from the compressor to increase the drying efficiency. The yarn drying room model was developed using Computational Fluid Dynamics (CFD) so as to study the distribution of air flow and temperature numerically. The most suitable design of the drying room considering the decrease of drying time such as the locations of hot air inlet and outlet were investigated. At the exhaust air outlet position, the average exhaust air temperature is 56°C, while the average flow rate and relative humidity are 1.75 m/s and 16.2 percent, respectively. The hydraulic calculation revealed that the appropriate duct size was 0.412 x 0.412 m2 width and height. The hot air temperature after transferring through air duct was decreased from 56°C to 52°C. The simulation results showed that the appropriate inlet position is at the ceiling and split into 4 inlet positions which had 0.152 x 0.152 m2 width and height. The most appropriate outlet position was 3 m above the ground in order to achieve the highest distribution of moisture content with standard deviation of 1.9 x 10-4. The locations which had the high accumulation of moisture were at the center and both sides of the drying room due to the low air turbulence. From this configuration, the drying time was decreased from 2 days to 89 minutes. Furthermore, after the 2 air circulators were installed in the drying room, the distribution of moisture content, represented in term of standard deviation, was about 1.5 x 10-4. As a consequence, the drying time could be reduced to 78 minutes, but the monthly electricity cost of air circulators was around 590 baht.

Thermo-Physical Properties And Mathematical Modeling Of Thin-Layer Drying Kinetics Of Medium And Long Grain Parboiled Rice Oraporn Bualuang; Supawan Tirawanichakul; Yutthana Tirawanichakul
ASEAN Journal of Chemical Engineering Vol 11, No 2 (2011)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

This research was to investigate some thermo-physical properties and to determine a mathematical model for describing drying kinetics for medium and long grain parboiled rice varieties. The thermo-physical properties in terms of equilibrium moisture content (EMC), apparent density, void fraction, specific heat capacity at moisture content ranging from 30 to 58% dry-basis (d.b.) for both Leb Nok Pattani (LNP) and Suphanburi 1 (SP 1) rice varieties were determined by conventional standard techniques.The evaluated results showed that EMC values for both rice varieties predicted by the GAB’s model yielded the best fitting with experimental data. To determine thermo-physical properties, the results stated that apparent density and specific heat capacity of parboiled LNP and SP1 rice varieties were linearly dependent on moisture content. In contrast, percentage of void fraction of medium grain LNP and long grain SP1 rice variety was inversely proportional to moisture content. For employing empirical thin-layer drying models, the Two terms model was the best fitting model to describe the experimental data for both rice varieties.

Pulping Of Vetiver Grass With NH4OH-KOH-AQ Mixtures Panitnad Chandranupap; Pravitra Chandranupap
ASEAN Journal of Chemical Engineering Vol 11, No 2 (2011)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

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.

Adsorption Compression Analysis for Supercritical Fluids using Ono-Kondo Model Panita Sumanatrakul; Chayanoot Sangwichien; Gregory Aranovich; Marc D Donohue
ASEAN Journal of Chemical Engineering Vol 11, No 2 (2011)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

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.

Electrochemical Behaviour Of Ferrocene/Ferricinium Redox System In Pure And CO2 Saturated [C6MIM][PF6] Sebastien Chanfreau; Liang-Nian He; Bing Yu
ASEAN Journal of Chemical Engineering Vol 11, No 2 (2011)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

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.

Nanotitania-Activated Carbon with Enhanced Photocatalytic Activity: A Comparison Between Suspended and Immobilized Catalyst for Turquoise Blue Removal Jurex Gallo; Josephine Borja; Susan Gallardo; Pailin Ngaotrakanwiwat; Cris Salim; Hirofumi Hinode
ASEAN Journal of Chemical Engineering Vol 11, No 2 (2011)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

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.

DEACTIVATION OF PALLADIUM CATALYST SUPPORTED BY ALUMINA IN THE PRODUCTION OF GLYPHOSATE Edia Rahayuningsih; I Made Bendiyasa; Nuryono Nuryono; Jupiter Jupiter
ASEAN Journal of Chemical Engineering Vol 11, No 2 (2011)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

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.

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Ari Pramudyantoro

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+62274555320

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ajche.ft@ugm.ac.id

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Jln. Grafika No. 2 Kampus UGM Yogyakarta Indonesia 55281

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Daerah istimewa yogyakarta

INDONESIA

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Home Page

OAI Link

Editorial Team

Contact

Reviewer

Google Scholar

Contact Name Ari Pramudyantoro

Contact Email ajche.ft@ugm.ac.id

Phone +62274555320

Journal Mail Official ajche.ft@ugm.ac.id

Editorial Address Jln. Grafika No. 2 Kampus UGM Yogyakarta Indonesia 55281

Location Kab. sleman, Daerah istimewa yogyakarta INDONESIA

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Abstract

Contact Name
Ari Pramudyantoro

Contact Email
ajche.ft@ugm.ac.id

Phone
+62274555320

Journal Mail Official
ajche.ft@ugm.ac.id

Editorial Address
Jln. Grafika No. 2 Kampus UGM Yogyakarta Indonesia 55281

Location
Kab. sleman,

Daerah istimewa yogyakarta

INDONESIA