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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 12, No 1 (2012)" : 8 Documents clear

Characteristics of Flame Shapes and Map For LPG and Hydrogen Inverse Confined Diffusion Flames at High Level of Fuel Excess Yazid Bindar; Anton Irawan
ASEAN Journal of Chemical Engineering Vol 12, No 1 (2012)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

A combustion flame can be generated by locating the air jet supply inside the fuel jet supply. This flame is referred as an inverse diffusion flame. The size and structure of inverse diffusion flame were studied experimentally. The experiment was conducted for LPG and Hydrogen fuels. The inlet fuel and air flow rates are supplied at high level of fuel excess for its combustion reaction. These two fuels generated the flame shape having two parts. At lower part, the flame is wider and serves as a base of the flame. The upper part is longer and acts as a flame tower. The base flame was a weak flame resulted by a rich fuel-air mixture. The tower flame is formed by mixing between the entrained fuel and the air. The flame length decreases with the increase on the momentum ration between fuel and air. The flame height correlates to the fuel and air Reynold number ratio, Refu/Rea. The development of the flame shapes from continues to strong base-tower flame shape is mapped by air and fuel inlet momentum rate. Very low fuel and air momentum rates result laminar flame and continuous shapes. The turbulent flames having base-tower shape are formed at high air momentum rate. The oxygen profiles shows that the oxygen concentration decays from the burner tip, vanishes at some distance from the burner tip and increase again after this distance. The hydrogen is completely consumed before the flame tip is reached

Microstructural Dependency of Diffusion in Glass Flake-Reinforced Vinyl Ester Resins Bryan B. Pajarito; Masatoshi Kubouchi; Hiroyuki Tomita; Saiko Aoki
ASEAN Journal of Chemical Engineering Vol 12, No 1 (2012)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

Vinyl ester resins are utilized for long-term corrosion protection of metal, alloy, and concrete substrates against concentrated acids, alkalis, and solvents at high temperature. Glass flakes are usually added as fillers to reduce chemical diffusion within the vinyl ester matrix. A common industry practice is to use glass flakes with large aspect ratio, high volume fraction, and in parallel alignment to surface in chemical contact for barrier applications. During processing and curing of glass flake-filled vinyl ester resins, irregular microstructures such as reduced flake aspect ratio and random orientation of flakes are commonly observed. Such microstructures can affect the overall chemical diffusion, resulting to barrier properties less predictable by simple diffusion models. Therefore, in this study, a simple 2D random walk simulation procedure is used in attempt to estimate the microstructural dependency of diffusion in glass flake-reinforced vinyl ester resins. While the random walk simulations are in good agreement with the tortuosity-based diffusion models in terms of microstructural effects, in most cases the simulation results are inconsistent with the experimental measurements of acid diffusion in glass flake-filled vinyl ester resins. A possible cause for this is the poor adherence of vinyl ester resin to glass flakes. Osmotic cracks are also formed during immersion which also influences overall diffusion through the material.

Synthesis of Ternary Homogeneous Azeotropic Distillation Sequences: Entrainer Selection Sutijan Sutijan; Megan Jobson; Robin Smith
ASEAN Journal of Chemical Engineering Vol 12, No 1 (2012)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

This paper presents a methodology for automatic selection of entrainers for separating binary azeotropic mixtures using homogeneous azeotropic distillation. A new classification system for ternary mixtures based on the termini of distillation boundaries and the type (stability) of products and azeotropes is proposed. The new characterisation system is able to link candidate entrainers to flowsheet structures which can facilitate the separation. Existing entrainer selection criteria are extended to accommodate other promising entrainers, including light, intermediate and heavy-boiling entrainers.

Characterization and Photocatalytic Activity of Nano-TiO2 Doped with Iron and Niobium for Turquoise Blue Dye Removal Nhat Minh Doan; Carl Renan Estrellan; Anton Purnomo; Susan Gallardo; Chris Salim; Hirofumi Hinode
ASEAN Journal of Chemical Engineering Vol 12, No 1 (2012)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

The nano-TiO2 photocatalysts doped with Iron and Niobium for dye wastewater treatment were prepared by temperature-controlled sol-gel method. The effects of these dopants on the physical and chemical properties of TiO2 were compared with the commercially available Degussa TiO2 P25. Among these characteristics are crystalline size, the presence of absolute anatase phase, band gap energy and specific surface area. The characterization data were correlated to photocatalytic activities using Turquoise blue dye (TBD) as model pollutant. Single doping (with Nb) and co-doping (Fe and Nb) catalyst reached complete decolorization within 2.5 hours and 3 hours. In addition, their kinetic reaction rate constants of apparent first-order model are 0.0258 min-1 and 0.0225 min-1, respectively. The presence of Nb as traps is considered to play a crucial key in enhancing the photocatalytic activity.

Water Treatment by Coagulation-Flocculation Using Ferric Sulphate as Coagulant Hary Sulistyo; Wahyudi Budi Sediawan; Sarto Sarto; Yusuf Yusuf; Ronald Nainggolan
ASEAN Journal of Chemical Engineering Vol 12, No 1 (2012)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

Coagulation and flocculation are two essential processes in water treatment. Their improvement on effectiveness and efficiency will give a significant influence for the overall process. The coagulation and flocculation processes involve a coagulant subsequently used to form flocks that can sink precipitate easily. In this research, the sample taken from Sermo Reservoir located in Kulon Progo Regency. The water was containing 320 ppm of colloid and suspended solids. Here, using a magnetic mixer stirrer, 500ml of raw water was mixed with a certain dosage of ferric sulfate in that used as the coagulant at a certain pH in a beaker glass through a high-speed mixing (240 rpm) for five minutes and low-speed mixing (60 ppm) for 10 minutes, respectively. Subsequently, the absorption was measured using UV/Visible. The result then shows 100 ppm for the optimum dosage of ferric sulfate and 9 for the optimum pH. The results indicate that a higher precipitation constant (kd) has resulted in a higher flock diameter. The correlation between the precipitation constant (kd) and the Reynolds number can be expressed as the following equation, kd = 51.98 Re0.3735 with an average relative error of 9.8%.

A Comparison of Carbon Molecular Sieve (CMS) Membranes with Polymer Blend CMS Membranes for Gas Permeation Applications W.Z. Wan Nurul Huda; M.A. Ahmad
ASEAN Journal of Chemical Engineering Vol 12, No 1 (2012)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

In this work, polyetherimide (PEI) was used as a main precursor to prepare carbon molecular sieve (CMS) membranes coated on a porous α-alumina disk via inert pyrolysis process. The PEI precursor was modified by blending with poly(ethylene glycol) (PEG) and its effect on the gas transport property of carbon membrane pyrolyzed at 873K was examined. The coating solution was prepared by PEI diluted in N-methylpyrrolidone (NMP) and coated onto support by dip-coating technique. Uniform CMS membranes were obtained by repeated dip-coating and pyrolysis of PEI and PEI/PEG. The structure and the single gas permeation properties of PEI and PEI/PEG CMS membrane were investigated.The thermal stability of CMS membranes prepared was determined by thermal gravimetric analysis (TGA). Elemental analysis, scanning electron microscopy (SEM), and Attenuated Total Reflectance Infrared (ATR-IR) Spectroscopy were employed to characterize the resulting membranes. The gas permeation of the CMS membranes was tested using three gases: methane, carbon dioxide, and oxygen and performed at 298K. The best performance was obtained by using PEI/PEG CMS membrane, whereby CO2 permeability should be 400.44x10-10 mol.m-2.s-1.Pa-1.

CO2 Selective Water Gas Shift Membrane Reactor : Modeling and Simulation Sang Kompiang Wirawan; Derek Creaser; I Made Bendiyasa; Wahyudi Budi Sediawan
ASEAN Journal of Chemical Engineering Vol 12, No 1 (2012)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

The concept of a CO2 selective water gas shift (WGS) membrane reactor has been modeled and simulated by a one-dimensional reactor and transport process in the membrane. The model was used to investigate the effect of temperature, total pressure, membrane thickness and area on the reactor performance. A Silicalite-1 membrane was considered to be integrated with the WGS reactor. The mass transport through the membrane was described by surface diffusion. Air was used as sweep gas on the permeate side of the membrane. The catalytic WGS kinetics were for a commercial Cu/ZnO catalyst for the lower-temperature WGS reaction. The WGS membrane reactor was sized to produce H2 sufficient for the production of 10 kW electrical power from a fuel cell. The modeling and simulation results showed that the WGS membrane reactor with a silicalite-1 membrane was capable of decreasing the CO concentration to about 675 ppm which is 70% less than that achievable at equilibrium conversion, but it would come at the cost of unacceptable H2 loss. Based on a minimum target of H2 loss, the optimum outlet CO concentration achieved by the silicalite-1 membrane reactor was about 1310 ppm, under a range of limited conditions. The modeling study showed that both the WGS reaction rate and the CO2/H2 selective permeation played an important role on the overall reactor performance.

Synthesis And Performance Of Thin Film Composite Nanofiltration Polyester Membrane For Removal Of Natural Organic Matter Substances N.A. Jalanni; M.N. Abu Seman; C.K. M Faizal
ASEAN Journal of Chemical Engineering Vol 12, No 1 (2012)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

Nanofiltration (NF) polyester thin-film composite (TFC) membranes have been prepared by interfacial polymerization using commercial polyethersulfone membrane support. At 6% (w/v) triethanolamine (TEAO) concentrations in the aqueous solution and a range of interfacial polymerization times in the organic solution containing trimesoyl chloride (TMC) were studied. Nanofiltration membranes were produced with varying properties through interfacial polymerization technique. The ability to use NF membranes with varying properties will improve overall process efficiency. This study has shown that through interfacial polymerization technique, the variation of reaction time as well as can affect the performance of the membrane produced. As a result, increasing the reaction time resulted in decreasing water permeabilities. Polyester with some amide group produced after interfacial polymerization occurred as shown by FT-IR spectra. Straight lines were obtained between Jw and ΔP and the water flux of distilled water shown that flux is directly proportional to transmembrane pressure (TMP). At low reaction time (5 min), the water flux has no significant effect on water permeance. So, the reaction time has a significant effect on the growth of thin film.

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Ari Pramudyantoro

Contact Email
ajche.ft@ugm.ac.id

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+62274555320

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ajche.ft@ugm.ac.id

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

Location
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Daerah istimewa yogyakarta

INDONESIA

Abstract

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Abstract

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