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ASEAN Journal of Chemical Engineering
The ASEAN Chemical Engineers as well as some Japanese Chemical Engineers organized a symposium for the ASEAN chemical engineers since 1994. This is called "Regional Symposium of Chemical Engineering - RSCE". The primary objectives of this symposium is to serve as venue for the dissemination of the research output done by chemical engineers, to establish linkages among the chemical engineers in the ASEAN region, and lastly, the need for Japan to strengthen ties with ASEAN countries.
Articles
242
Articles
Effect Of Pre-Treatment And Inoculant During Composting Of Palm Oil Empty Fruit Bunches

A.Y. Zahrim, I.K.T. Yee, E.S.C. Thian, S.Y. Heng, J. Janaun, K.P. Chong, S.K. Haywood, V. Tan, T. Asis, T.M.T.M.A. Al-Mizi

ASEAN Journal of Chemical Engineering vol. 17 no.2 (2017)
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Abstract

In this work, untreated empty fruit bunch (EFB) or microwave-assisted NaOH pretreated EFB with palm oil mill effluent (POME) were composted under mesophilic conditions either in the presence or absence of Bacillus amyloliquefaciens D203 for sixty days. During pretreatment conditions, the EFB was mixed with 1% (w/w) sodium hydroxide and then exposed to microwave irradiation. The composting process was evaluated based on the evolution of pH, electrical conductivity, moisture content, organic matter loss, zeta potential and phytotoxicity. The strain Bacillus amyloliquefaciens D203 is not suitable for EFB-POME composting due to lower organic matter loss. The microwave-assisted NaOH pretreatment contributed to ~15% more organic matter loss than was found in the untreated sample while its germination index was >50%.

Transient Cooling Of A Cylinder In Cross Flow Bounded By An Adiabatic Wall

Nawaf H Saeid, Bashir S. Abusahmin

ASEAN Journal of Chemical Engineering vol. 17 no.2 (2017)
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Abstract

The present study investigates the parameters controlling the cooling process of a cylindrical food in the storage area for a period of time. Transient analysis of the conduction and convection (conjugate) heat transfer from a cylindrical food, or a cylindrical can filled with food is selected for numerical simulations. The cylinder is bounded by an adiabatic wall and the cold air is flowing normal to the cylinder axis (cross flow). The parameters investigated are: Reynolds number, food thermal properties (density, specific heat and thermal conductivity) and the cooling period. The range of the Reynolds number is selected from 50 to 500 to be in laminar flow conditions. Three different materials were selected according their thermal properties. The results are presented to show the cooling process starting from blowing cold air stream on the cylinder for a period of 4 hours. The results show that the food with low thermal inertia is cooled faster than that of high thermal inertia. The present results show also that the cooling process can be shortened by increasing the air velocity and lower its temperature.

Photocatalytic Hydrogen Production over Ni/La-NaTaO3 Nanoparticles from NaCl-water Solution in the Presence of Glucose as Electron Donor

Husni Husin, Komala Pontas, Yunardi, Adi Salamun, Pocut Nurul Alam, Fikri Hasfita

ASEAN Journal of Chemical Engineering vol. 17 no.2 (2017)
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Abstract

Nanoparticles La-NaTaO3 photocatalyst has been synthesized via a sol-gel route. A Ni nanoparticle (NPs) as a cocatalyst is loaded on La-NaTaO3 by a simple impregnation method. The products are characterized by X-ray diffraction (XRD), scanning electron microscope (SEM), a high-resolution transmission electron microscope (HRTEM) and X-ray photoelectron spectroscopy (XPS). X-ray diffraction of the La-NaTaO3 samples shows perovskite-type crystalline orthorhombic structure. Small particulate solids of La-NaTaO3 (30-250 nm) are observed by SEM measurement. The nickel particles are detected from HRTEM images is around 4-8 nm. The hydrogen evolution over La-NaTaO3 with NaCl is much higher than that without NaCl. The photoactivity of La-NaTaO3 is enhanced when Ni is loaded on the surface of La-NaTaO3. The optimum loading amount of nickel is found to be 0.3 wt.% for La-NaTaO3, and it is more effective for H2 production from NaCl-water solution in the presence glucose. It is revealed that the loaded Ni can interact with each other and cooperate on improving the photocatalytic activity. In the case of glucose as an electron donor, the activity of photocatalytic hydrogen generation over Ni/La-NaTaO3 increases dramatically. NaCl and glucose can promote markedly the photocatalytic hydrogen evolution. The Ni/La-NaTaO3 nanoparticles system appears to be a promising candidate, which is very important to practical applications, including the production of H2 from NaCl-water solution in the presence of glucose.

Ultrasonic Assisted Photolytic Degradation of Reactive Black 5 (RB5) Simulated Wastewater

Collin G. Joseph, Yun Hin Taufiq-Yap, Vigneswar Krishnan

ASEAN Journal of Chemical Engineering vol. 17 no.2 (2017)
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Abstract

The present study is based on a hybrid advanced oxidation process (AOP) of sono-photolysis system, of which sonication (35 kHz) and photolysis UV-C (254nm) were applied simultaneously to effectively degrade a selected recalcitrant dye-based pollutant, Reactive Black 5 (RB5). The influence of the solution pH and concentration were manipulated throughout this study to investigate the sonophotodegradation kinetics and synergistic effects on the RB5 degradation. Increasing the solution concentration resulted in lowered degradation rate due to the inner filter effect by the dye molecules and reduced the generation of hydroxyl radicals. The results confirmed that the sonophotolysis rate was better at basic medium (67.7%) in comparison to acidic medium (46.9%) due to the ionization of RB5. Synergistic effects were analyzed based on the first order kinetic rate model. It was found that the synergistic effect was observed for all the experiments conducted which resulted from an increase in the (•OH) radicals due to the photolysis of H2O2 formed by the sonolysis process. This hybrid system, sonophotolysis system, was able to degrade RB5 into intermediates with a total reaction time of 1h.

Assessment of Aqueous Lithium-based Salt Solutions as Working Fluid for Absorption Chillers using Aspen Plus

Adonis P. Adornado, Allan N. Soriano, Vergel C. Bungay

ASEAN Journal of Chemical Engineering vol. 17 no.2 (2017)
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Abstract

Absorption chillers are a viable option for providing waste heat-powered cooling or refrigeration, thereby improving overall energy efficiency-less primary energy input, lower emissions, and cost savings. This study focuses on the assessment of aqueous lithium-based salt solutions as working fluid for absorption chiller in exploring the possibility of developing new mixtures for absorption chillers to improve the performance of the absorption refrigeration systems (ARSs). In this paper, the coefficient of performance (COP) of a single-effect absorption chiller using aqueous lithium-based salt solutions (LiF-H2O, LiCl-H2O, LiBr-H2O, and LiI-H2O) as working fluid was assessed using Aspen Plus®. The simulation results obtained showed that the mass and energy were well balanced for all systems. Furthermore, a direct proportionality relationship between COP of absorption chillers and the vant Hoff factor, i of dissociated aqueous salt solutions was observed. The highest COP value is 0.8930 for LiI-H2Oamong others.

Open Loop Recycling of Recycled Polypropylene for Motorcycle Saddle Application

Piyachat Wattanachai, Benjawan Buasathain, Christian Antonio, Susan Roces

ASEAN Journal of Chemical Engineering vol. 17 no.2 (2017)
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Abstract

This research investigated the possibility of using polymer blends of virgin and recycled polypropylene (PP) for a motorcycle saddle application. Three different recycled PPs obtained from different sources contained carbon black (CB). Specimens were prepared by injection molding for mechanical property testing and color characterization whereas scraps from runners were used for thermal property testing. It was found that tensile and flexural properties of recycled PPs were better than those of virgin PP due to the fact that recycled PPs contained CB which is a reinforcing material. These properties were improved as the amount of recycled PP added increased. Since recycled PPs are strong materials, they are hence brittle resulting in lowering impact strength and percent elongation. The recycled PP sources and compatibility between virgin and recycled PPs strongly influence the blends properties. The melt flow index of the blends increased as the amount of the recycled PP increased because of the short polymer chains of recycled PP resulting from earlier processing. Blending virgin PP with recycled PP not only improves its properties, but also reduces raw material costs in the range of 5-13%. The advantage of open loop recycling is a wider recycled plastic market.

Biosynthesis and Kinetics of Silver Nanoparticles Formation by Reduction using Banana Kepok (Musa balbisiana) Peel Extract

Wara Dyah Pita Rengga, Dhimas Setiawan, Khosiatun

ASEAN Journal of Chemical Engineering vol. 17 no.2 (2017)
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Abstract

Biosynthesis and silver nanoparticles formation during the reduction of AgNO3 were carried out by using an aqueous peel extract of banana kepok (Musa balbisiana) as a stabilizing agent. The formation of the stable silver nanoparticles with different concentration of AgNO3 has resulted in mostly spherical particles. The Ultraviolet-Visible spectrophotometer, Transmission Electron Microscopy, X-Ray Diffractometer were used to characterize these biosynthesized silver nanoparticles. The spherical shaped nanoparticles were uniformly distributed with the range diameter of 5 to 50 nm and the particles were naturally crystallized with the crystal structure of the face-centered cubic geometry. Additionally, the kinetics of the formation process of silver nanoparticles was observed by the UV-Vis spectrophotometer. Based on the kinetic functions, the reduction process of banana peel extract had a constant formation rate of the autocatalytic process at 4.35 x 10-4/s.

A Passivity Approach to the Stabilization of Free-Radical Polymerization Reactor

Nguyen T. Sang, Hoang N. Ha, M.A. Hussain

ASEAN Journal of Chemical Engineering vol. 17 no.2 (2017)
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This work proposes a tracking error passivity-based multivariable control via feedback passivation for a class of free-radical polymerization systems in a continuously stirred tank reactor (CSTR). Firstly, this system dynamics with high nonlinearity is passivized by input coordinate transformations, the resulting passive system is then re-written into a canonical form strongly related to the so-called Port Control Hamiltonian structure. Actually, this representation allows to show the physical meanings of system dynamics such as dissipative, non-dissipative terms and supply rate. From this, a feedback controller based on tracking error is designed for the globally exponential stabilization at an arbitrarily chosen reference trajectory passing the desired equilibrium point. The theoretical developments are then illustrated for polystyrene polymerization system in the CSTR. The numerical simulations show that the trajectories of styrene polymerization system considered as an illustrative example of FRP system converges globally exponentially to the imposed trajectories.

Process Optimization of Carbon Dioxide Adsorption using Nitrogen-Functionalized Graphene Oxide via Response Surface Methodology Approach

Fritzie Hannah B. Baldovino, Nathaniel P. Dugos, Susan A. Roces, Armando T. Quitain, Tetsuya Kida

ASEAN Journal of Chemical Engineering vol. 17 no.2 (2017)
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This paper presents a response surface methodology approach in the optimization of the carbon dioxide temperature-programmed adsorption process using a new material referred as nitrogen-functionalized graphene oxide. This material was synthesized by loading nitrogen groups to graphene oxide using aqueous ammonia in supercritical condition. Later on, it was utilized as a sorbent for carbon dioxide adsorption. This process was optimized by implementing a response surface methodology coupled with a BoxBehnken design for the effects of three factors: adsorption temperature, carbon dioxide flow rate, and the amount of adsorbent. In analyzing the response surface, a model equation was generated based on the experimental data by regression analysis. This model equation was then utilized to predict optimum values of response. Furthermore, response optimizer was also conducted in identifying factor combination settings that jointly optimize the best response. 

Kinetics of Oil-in-Water Emulsion Stabilization using Lecithin and Biosilica

Lanny Sapei , Olivia Poppy Damayanti, Liliana Liliana

ASEAN Journal of Chemical Engineering vol. 17 no.1 (2017)
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Oil-in-water (O/W) emulsion has been widely used in food emulsions such as mayonnaise, dressings, and sauces. However, O/W emulsion is inherently thermodynamically unstable and easily destabilizes with time. Synthetic polymeric emulsifiers have been commonly used to stabilize these emulsions. However, those synthetic emulsifiers may induce obesity and other unexpected side-effects. In this experiment, bio-emulsifier mixtures consisting of soy lecithin and bio-silica were combined to stabilize the o/w emulsion in order to obtain more healthful food emulsions with acceptable quality. Lecithin concentrations were varied from 0.05-1.5% and concentrations of pure bio-silica particles derived from rice husks were in the range of 0.5-3%. The effects of the concentrations of these emulsifier mixtures on the O/W emulsions stability were studied. Additionally, the effects of storage temperatures on the O/W emulsions stability in the presence of both lecithin and bio-silica were investigated. The kinetics parameters of resulting O/W emulsions were analyzed using zero and first order kinetic models. In general, emulsions destabilized with time and followed the first order kinetic model. The destabilization rates of emulsions in the presence of emulsifier mixture would decrease by approximately 25-50% as compared to the destabilization rates of emulsions in the presence of lecithin or bio-silica as their sole emulsifier. Variations of lecithin and bio-silica concentrations in the emulsifier mixtures were not significant to the O/W emulsions stabilization. Furthermore, destabilization rate constants of O/W emulsions stored at the refrigerated temperature were ~2 times lower than those stored at room temperature.