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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 372 Documents

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Application of Autotrophic Denitrification to Nitrate-Contaminated Industrial Wastewater Rudi Nugroho; Hirokazu Takanashi; Makoto Hirata; Tadashi Hano
ASEAN Journal of Chemical Engineering Vol 3, No 1 (2003)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

An autotrophic denitrification system was applied to the treatment of industrial wastewater with very low C/N ratio. The experiments were conducted by both batch suspension and continuous column runs. The denitrification behavior in suspension runs obeyed the first-order reaction with the rate constants k1and k2 of 0.014 and 0.004 m3fg-SS-d, respectively. In the continuous runs, a column was packed with a mixture of granular sulfur and limestone. The microbes mostly composed of Thiobacillus denitrificans attached on the surface of sulfur particles like biofilm with an approximate thickness of 100 1m. The denitrification rate in the packed column was expressed by a half-order equation with the rate constant of 0.172 g-Nl/2- ml/2f(kg-S d). Lower denitrification extent of industrial wastewater compared with synthetic wastewater was concluded to be caused by the lack of alkalinity.Key Words: Autotrophic denitrification, Sulfur, Limestone, Packed column, Thiobacillus denitrificans

Steam Reforming of Methanol Over Cu/Al203/ZnO Catalysts Somchai Akaratiwa; Tammanoon Udomman
ASEAN Journal of Chemical Engineering Vol 3, No 1 (2003)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

In this research, steam reforming of methanol over Cu/Al2O3/ZnO catalysts was investigated. The catalysts were prepared by conventional co-precipitation and sequential precipitation methods. Especially, the sequential precipitation method were performed by varying the sequence of additions of copper, aluminum, and zinc nitrate solutions. The experimental results showed clearly that the preparation methods affected the performance of catalysts. The Cu/AI2O3/ZnO catalysts prepared by consecutively adding copper, aluminum, and zinc nitrate solutionsexhibited better performance. The effect of Al2O3/ZnO molar ratios on the activity of catalysts was also studied. It was found that the catalysts with 50:5:45 of Cu/AI2O3/ZnO molar ratio showed higher activity than others. In order to improve catalytic activity, Mn- or Cr-promoted over Cu/Alp.jZnO was also investigated. It was interesting to observe that either the Mn- or the Cr-promoted Cu/AI2O3/ZnO catalysts have higher activity than nonpromoted ones, indicating that Mn and Cr promoters give some synergistic effect.

Efect of pH on Growth, Spore Production and Spore Viability of Biocontrol Agent Trichoderma Harzianum in Submerger Fermentation Syahiddin Dahlanr Said; Masitah Hasan; K.B Romachandran
ASEAN Journal of Chemical Engineering Vol 3, No 1 (2003)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

The effect of pH medium on growth, spore production and spore viability of bicontrol agent Trichoderma harzianum were investigated in a batch farmenter in the range of 4 to 7. The biomass concentration of this fungus at pH 4,6 and uncontrolled pH were higher than at pH 5 and 7 after 18h incubation. The spore produced by the fungus at 6,7 and uncotrolled pH was higher than others. the highest level of spore production (6.67x107 spores/ml) occured at unctrolled pH, but the spore produced in the culture grown at 7 has a higher viability (52,5%) compared to those grown at other pH.

Kinetic Analysis of Phenol Biodegradation by Isolated Bacteria and Mixed Culture by Cells Immobilized on Loofa (Lugga Cylindrica) Sponge in Airlift Bioreactior Faisal Faisal; Yasunori Tanji; Hajime Unno
ASEAN Journal of Chemical Engineering Vol 3, No 1 (2003)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

Varios contaminated soil samples were examined for isolation of microorganisms responsible for phinol degradation. One type pure culture gram positive bacterua was isolated and identified as Bacillus pulvifaciens. isolated bacteria and an activated sludge were acclimated for 75 days to a medium containing phenol is a speratae 250 ml Erlenmeyer flasks. After this period of time, biomass was transferred into airlift bioreactor with looga sponge for cells immobilization and acclimation which was operated by fill and draw moder faro 70 days. The immobilized cells gres wthin the void space of the loofa spongem reaching a high cells concentration of 21.4 g-calees/l-sponge volume and the free cells in the effluent became arround of 0.7 g/l. The performance of airlift bioreactir for 27 hours operation after acclimation period, showed that decrease in phenol concentration after 24th hour culture with isolated bacteria and the activated sludge culture were 99.8% and 84,2% removal, respectivaly. The phenol and COD degradation by the isolated bacteria was higher than that of the activated sludge culture. Based on the experimental data, kinetic model was discussed. through the model the biokinetic paramters were evaluated, which represented the behavior of eractor very well.

Avoiding Chaotin Instability under PID Control of Plythylene Fluidized Bed Reactor (UNIPOL Procees) Nayef Mohamed Ghasem; Mohamed Azlan Hussain
ASEAN Journal of Chemical Engineering Vol 3, No 1 (2003)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

Modeling investigation showed that static and dynamic bifurcation behavior covers wide regions of the design and operatin domain of the fluidized bed reactor for polythylene production. In some cases, if comes across that the optimum static state is unstable and surrounded by a periodic branch with large tempertature oscillations causing fomidably high termperature far above the melting point of the polymer. A proportional-derivative-integral controller has been investigated for the stabilization of these desirableunstable steady states and the characteristic of the closed loop control system are presented and discussed. Even under the PID control scheme it was observed that care should be taken dor selecting suitable control gain to avoid instability.

Characterization of Titania (TiO2) Catalysts Prepared by Sol-Gel Method Marwan Marwan; Naoto Azuma; Akinori Maezawa; Shigeo Uchida
ASEAN Journal of Chemical Engineering Vol 3, No 1 (2003)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

Various TiO2 catalysts in powder form were prepared ny sol-gel method and then characterized for X-ray diffraction and BET surface area. VAriation in composistion of reactants, choice of hydrolysing catalyst, calcination temperature, and method of drying were among preparative variable evaluated. Addition Pt, Fe2O3, CuO and SiO2 on the catalysts was also carried out during the initial stage of sol formation. XRD analysis suggest that all catalysts calcined at 450'C were compeltelu in anatase phase. BET surface area of the catalysts revealed that the catalysts prepared using HNO3 as hydrolysing catalyst, have a surface area larger than the commercial Degussa P25 TiO2 catalyst, with the highest area of 126m2/g. The addition of metals resulted in a lower surface area, while silica provided a considerable incdease in surface area, at 257 m2/g. Analyses of isotherms plot and BJH desorption plots suggest that particle pores were dominated by a bottle-like share. However, the photocalatylstic activity of these catalysts in te degradation of sufactant failed to meet the perfomance rating of Degussa P23 TiO2 catalyst, probably due to less access of surfactant into interbal surface of the prepared catalysts. Degradation of the surfactant usidng different particle sizes suggests that the external surface of TiO2 catalysts was important under liquid phase degradation.

Multi-objective Optimization of Succinic Acid Production from Empty Fruit Bunch R.H. Hafyan; W.D. Prasetyo; L Bhullar; Z.A. Putra; M.R. Bilad; M.D.H Wirzal; N.A.H.M. Nordin
ASEAN Journal of Chemical Engineering Vol 19, No 1 (2019)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

Empty Fruit Bunch (EFB) produced in plantation mill activities in Malaysia creates a major disposal problem. On the other hand, sustainability issues have driven industries to overcome the depletion of fossil fuels and reduction of greenhouse gases emissions. Therefore, as a renewable source, EFB can be an attractive option to address the above problems by converting it into fuels and chemicals. Succinic acid, one of 12 chemical building blocks identified by DOE to be used in synthesis of high-value materials, can be produced from biochemical conversion of the EFB. The present study evaluates succinic acid production process using EFB as the raw material from the perspective of three pillars of sustainability, namely economic, environment, and safety. Flowsheet modeling and techno-economic analysis methods are applied, followed by a multi-objective optimization using genetic algorithm method that simultaneously accounts for maximization of Net Present Value (NPV) and minimization of both Global Warming Potential (GWP) and Toxicity Damage Index (TDI). The pareto frontier reveals a trade-off among all objectives that the maximum NPV is 1,619 MMSD at the maximum EFB of 71,900 kg/hour. Meanwhile, the minimum GWP (12.4 kg CO2-eq/kg succinic acid) and TDI (4.5) are acquired at the minimum EFB of 50,000 kg/hour.

Effects of Microbial Starter Composition on Nutritional Contents and Pasting Properties of Fermented Cassava Flour M.T.A.P. Kresnowati; L. Turyanto; A. Zaenuddin; K. Trihatmoko
ASEAN Journal of Chemical Engineering Vol 19, No 1 (2019)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

Fermentation of cassava chips prior to drying and milling processes improves cassava flour quality: i.e. lower cyanogenic content, remove specific odour and colour. Composition of microbial starter applied to the fermentation may affect the microbial population during the fermentation and thus directs the process and the produced flour properties. This study mapped the effects of microbial starter composition on the microbial profiles during the fermentation and the corresponding nutritional contents as well as pasting properties of the produced fermented cassava flour (fercaf). Combinations of Lactobacillus plantarum, Bacillus subtilis and Aspergillus oryzae, that were selected based on their enzymatic activities, were evaluated. The addition of microbial starter was shown to affect the dynamics in microbial population during the fermentation. The addition of lactic acid bacteria accelerated the release of cyanogenic glycoside and starch conversion to simpler sugars, the addition of B. subtilis improved the disruption of cassava fibres, whereas the addition of A.oryzae was shown to increase the protein content of fercaf. The different microbial starter added to fermentation system also resulted in different pasting properties of fercaf. Microbial starter composition can be designed as such for the production of a particular flour property.

Coal Fly Ash-based Geopolymer Spheres Coated with Amoxicillin and Nanosilver for Potential Antibacterial Applications Brandon Cyril S. Lira; Sophia Bianca A. Dellosa; Casey Irene L. Toh; Al Patrick A. Quintero; Andre Leopold S. Nidoy; Kimmie Dela Cerna; Derrick Ethelbhert C. Yu; Jose Isagani B. Janairo; Michael Angelo B. Promentilla
ASEAN Journal of Chemical Engineering Vol 19, No 1 (2019)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

Geopolymers are emerging “green” materials for its low embodied energy and carbon footprint, and its potential to valorize wastes, such as coal fly ash. It is an inorganic cementitious material formed from the polymerization of aluminosilicates in an activating solution such as that of alkali hydroxides or silicates. Their superior mechanical properties, including heat and fire resistance make them an excellent material for diverse applications. Recent studies have also exploited the tunable open porosity and adsorbing properties of geopolymers. Our work thus explores the potential of porous geopolymer spheres for antibacterial applications. These spheres were synthesized using coal fly ash as the geopolymer precursor and the porous surface is coated with either amoxicillin or silver nanoparticles (AgNPs) adsorbed in the matrix. For the AgNP geopolymer spheres, SEM images show spherical nanostructures when using ascorbic acid as a reducing agent, while spherical, cubical, and wire structures were observed when reduced using NaBH4. Indication from UV-Vis results also suggests the gradual release of both amoxicillin and AgNPs in the solution from the functionalized geopolymer spheres. Using E. Coli as the test organism for a modified disk diffusion assay, both showed zones of inhibition against the bacteria. Further tests on antibacterial application of AgNP geopolymer spheres show their effectiveness to kill at least 95% of the E. coli in a water sample initially containing 105 cfu/mL in just 30 minutes.

Effect of Pressure and Syngas Composition on Direct Synthesis of Dimethyl Ether using Dual Bed Catalyst Aisyah Ardy; Jenny Rizkiana; Melia Laniwati Gunawan; Herri Susanto
ASEAN Journal of Chemical Engineering Vol 19, No 1 (2019)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

National General Energy Plan of Indonesia 2017 (RUEN 2017) stated that dimethyl ether (DME) is appointed as a blending of LPG to reduce LPG imports. DME can be made with two reaction pathways, namely direct synthesis and indirect synthesis. The objective of this study was to determine the effect of pressure and syngas composition on the direct synthesis of DME using dual fixed bed catalyst. The research was carried out with two types of catalyst: M-xxx as a commercial catalyst for methanol synthesis and γ-Al2O3 as catalyst for dehydration of methanol to DME. The later was prepared in our Laboratory of Chemical Reaction Engineering and Catalysis, ITB. The dual catalyst experiment was carried out at 5 and 7 bars, and a fixed temperature of 240oC. The mass ratio of the M-xxx to γ-Al2O3, so-called M/D ratios, were varied from 1/9 to 9/1. Two type of syngas were used, i.e. SA containing only H2 and CO with a SN of 2,3 and SB containing 4% CO2 with SN of 1,8. The dual bed with a M/D ratio of 1/4 gave a CO conversion up to 62% at 5 bars and 240oC (SA). As pressure increased, the conversion of CO and H2 increases to 85% and 83% at 7 bar and 240oC (SA). The presence of CO2 (SB) decreases catalyst activity, as indicated by the decrease in conversion of CO and H2 to 56% and 54%, at 7 bar and 240oC.

Page 26 of 38 | Total Record : 372

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Ari Pramudyantoro

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Jln. Grafika No. 2 Kampus UGM Yogyakarta Indonesia 55281

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Home Page

OAI Link

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Contact Name Ari Pramudyantoro

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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

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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