Article Per Year (5 Year)
p-Index From 2021 - 2026
0.23
P-Index
This Author published in this journals
All Journal Reaktor Journal of Engineering and Technological Sciences JURNAL SELULOSA ASEAN Journal of Chemical Engineering Jurnal Teknologi Bahan dan Barang Teknik Jurnal Teknik Kimia Indonesia Bulletin of Chemical Reaction Engineering & Catalysis
S. Subagjo
Chemical Engineering Department, Institut Teknologi Bandung
Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Control & Systems Engineering Education Electrical & Electronics Engineering Energy Engineering Materials Science & Nanotechnology

Published : 31 Documents Claim Missing Document
Claim Missing Document
Check
Articles

Found 31 Documents
Search

 1   2   3   4 
Permodelan dan simulasi reaktor mikro untuk produksi hidrogen sebagai umpan sel bahan bakar kendaraan bermotor Yogi Wibisono Budhi; S Subagjo
Jurnal Teknik Kimia Indonesia Vol 6, No 2 (2007)
Publisher : ASOSIASI PENDIDIKAN TINGGI TEKNIK KIMIA INDONESIA (APTEKIM)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/jtki.2007.6.2.6

Abstract

The terminology of micro-reactor development is one of the keywords in process intensification, which plays an important role, particularly in the reaction system requiring extremely large heat and mass transfers.  This paper  conveys an idea about miniaturization of the combustion engine through a combination of fuel processor  system  and fuel  cell system. Hydrogen as a fuel cell feedstock is provided in-situ by methanol reforming. The synthesis gas produced  by reformer is introduced into preferential oxidation reactor to remove CO before it enters the fuel cell. The process system for producing hydrogen is equipped in the micro-technology package as an answer to hydrogen storage at  high pressure,  which meets several shortcomings. Keywords: Process intensification; Modeling and simulation; Micro-reactor technology AbstrakTerminologi pengembangan reaktor mikro merupakan salah satu 'kata kunci' dalam intensifikasi proses yang memainkan peranan penting, terutama dalam sistem reaksi yang memerlukan laju perpindahan panas dan massa yang besar. Makalah ini menyampaikan gagasan  tentang miniaturisasi  mesin  kendaraan  bermotor  melalui kombinasi  sistem proses or bahan bakar dan sel bahan bakar. Hidrogen yang diperlukan sebagai  umpan sel bahan bakar disediakan secara insitu dari reformasi metanol. Gas sintesis dari reformer diumpankan ke dalam reaktor oksidasi preferensial untuk menyisihkan CO sebelum diumpankan ke dalam sel bahan bakar. Rangkaian sistem proses penyedia hidrogen secara insitu ini dikemas dalam paket teknologi mikro sebagai jawaban atas kebuntuan sistem penyediaan hidrogen pada  tekanan tinggi yang memiliki banyak kelemahan.Kata Kunci: Intensifikasi proses; Pemodelan dan simulasi; Teknologi reaktor mikro
Synthesis and Activity Test of Cu/ZnO/Al2O3 for the Methanol Steam Reforming as a Fuel Cell’s Hydrogen Supplier IGBN Makertihartha; Subagjo Subagjo; Melia Laniwati Gunawan
Journal of Engineering and Technological Sciences Vol. 41 No. 1 (2009)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.eng.sci.2009.41.1.3

Abstract

The  synthesis  of  hydrogen  from  hydrocarbons  through  the  steam reforming  of  methanol  on  Cu/ZnO/Al2O3  catalyst  has  been  investigated.  This process is assigned to be one of the promising alternatives for  fuel cell hydrogen process source. Hydrogen synthesis from methanol can be carried out by means of  methanol  steam  reforming  which  is  a  gas  phase  catalytic  reaction  between methanol and water. In this research, the  Cu/ZnO/Al2O3  catalyst  prepared by the dry  impregnation  was  used.  The  specific  surface  area  of  catalyst  was  194.69 m2/gram.The  methanol  steam  reforming  (SRM)  reaction  was  carried  out  by means of the injection of gas mixture containing methanol and water with 1:1.2 mol ratio and 20-90 mL/minute feed  flow rate to a fixed bed reactor loaded by 1 g of catalyst. The reaction temperature was 200-300 °C, and the reactor pressure was 1 atm. Preceding  the reaction, catalyst was reduced in the H2/N2  mixture at 160  °C.  This  study  shows  that  at  300  °C  reaction  temperature,  methanol conversion  reached  100%  at  28  mL/minute  gas  flow  rate.  This  conversion decreased  significantly  with  the  increase  of  gas  flow  rate.  Meanwhile,  the catalyst prepared for SRM  was stable in 36 hours of operation at 260  °C. The catalyst exhibited a good stability although the reaction condition was shifted to a higher gas flow rate.
Synthesis of -Al2O3 Catalyst Support from Kaolin of Indonesian Origin Tjokorde Walmiki Samadhi; Subagjo Subagjo; Kevin R. Lismana; Khasin Fuadi
Journal of Engineering and Technological Sciences Vol. 43 No. 2 (2011)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/itbj.eng.sci.2011.43.2.3

Abstract

Kaolin  has  been  identified  as  a  potential  raw  material  for  the production of  -Al2O3  for  hydrotreating  catalyst support. This work explores the technical  feasibility  of  applying  the  potassium  hydroxide  (KOH)  e xtraction synthesis route on kaolin  from the Belitung  Island  in Indonesia. The application of  a  published  synthesis  method  to  Belitung  kaolin  requires  an  approximately twofold  increase  in  kaolin  calcination  time,  an  increase  in  kaolin  calcination temperature from 950 to 1000 °C, and a tenfold increase in metakaolin extraction time, to obtain a specific surface area higher than 200 m2/g. The highest specific surface area of 233 m2/g was obtained when  the kaolin was calcined at 1000 °C for 24 hours, and the  metakaolin  was extracted by concentrated KOH  solution for 12 hours.  Phase characterization of the final product confirmed the formation of -Al2O3, but with the inclusion of low-surface area -Al2O3 phase.
Determination of Kinetic Parameters for Methane Oxidation over Pt/γ-Al2O3 in a Fixed-Bed Reactor Vita Wonoputri; Mohammad Effendy; Yogi Wibisono Budhi; Yazid Bindar; S. Subagjo
Journal of Engineering and Technological Sciences Vol. 45 No. 2 (2013)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2013.45.2.7

Abstract

This paper describes akinetic study for the determination of the kinetic parameters of lean methane emission oxidation over Pt/γ-Al2O3 in a dedicated laboratory scale fixed bed reactor. A model ofthemechanistic reaction kinetic parameters has been developed. The reaction rate model was determined using therate-limiting step method, which was integrated and optimized to find the most suitable model and parameters. Based on this study, the Langmuir-Hinshelwood reaction rate model with the best correlationis the one where the rate-limiting step is thesurface reaction between methane and one adsorbed oxygen atom. The pre-exponential factor and activation energy were 9.19 x 105 and 92.04 kJ/mol, while the methane and oxygen adsorption entropy and enthalpy were "“17.46 J/mol.K, "“2739.36 J/mol,"“16.34 J/mol.K, and "“6157.09 J/mol, respectively.
Homogeneity of Continuum Model of an Unsteady State Fixed Bed Reactor for Lean CH4 Oxidation S. Subagjo; Yogi Wibisono Budhi; M. Effendy; Yazid Bindar
Journal of Engineering and Technological Sciences Vol. 46 No. 2 (2014)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2014.46.2.6

Abstract

In this study, the homogeneity of the continuum model of a fixed bed reactor operated in steady state and unsteady state systems for lean CH4 oxidation is investigated. The steady-state fixed bed reactor system was operated under once-through direction, while the unsteady-state fixed bed reactor system was operated under flow reversal. The governing equations consisting of mass and energy balances were solved using the FlexPDE software package, version 6. The model selection is indispensable for an effective calculation since the simulation of a reverse flow reactor is time-consuming. The homogeneous and heterogeneous models for steady state operation gave similar conversions and temperature profiles, with a deviation of 0.12 to 0.14%. For reverse flow operation, the deviations of the continuum models of thepseudo-homogeneous and heterogeneous models were in the range of 25-65%. It is suggested that pseudo-homogeneous models can be applied to steady state systems, whereas heterogeneous models have to be applied to unsteady state systems.
Dynamic Behavior of Reverse Flow Reactor for Lean Methane Combustion Yogi W. Budhi; M. Effendy; Yazid Bindar; S. Subagjo
Journal of Engineering and Technological Sciences Vol. 46 No. 3 (2014)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2014.46.3.5

Abstract

The stability of reactor operation for catalytic oxidation of lean CH4 has been investigated through modeling and simulation, particularly the influence of switching time and heat extraction on reverse flow reactor (RFR) performance. A mathematical model of the RFR was developed, based on one-dimensional pseudo-homogeneous model for mass and heat balances, incorporating heat loss through the reactor wall. The configuration of the RFR consisted of inert-catalyst-inert, with or without heat extraction that makes it possible to store the energy released by the exothermic reaction of CH4 oxidation. The objective of this study was to investigate the dynamic behavior of the RFR for lean methane oxidation and to find the optimum condition by exploring a stability analysis of the simple reactor. The optimum criteria were defined in terms of CH4 conversion, CH4 slip, and heat accumulation in the RFR. At a switching time of 100 s, the CH4 conversion reached the maximum value, while the CH4 slip attained its minimum value. The RFR could operate autothermally with positive heat accumulation, i.e. 0.02 J/s. The stability of the RFR in terms of heat accumulation was achieved at a switching time of 100 s.
Synthesis of NaY Zeolite Using Mixed Calcined Kaolins Subagjo Subagjo; Endang Sri Rahayu; Tjokorde Walmiki Samadhi; Melia Laniwati Gunawan
Journal of Engineering and Technological Sciences Vol. 47 No. 6 (2015)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2015.47.6.4

Abstract

Kaolin is one of several types of clay minerals. The most common crystalline phase constituting kaolin minerals is kaolinite, with the chemical composition Al2Si2O5(OH)4. Kaolin is mostly used for manufacturing traditional ceramics and also to synthesize zeolites or molecular sieves. The Si-O and Al-O structures in kaolin are inactive and inert, so activation by calcination is required. This work studies the conversion of kaolin originating from Bangka island in Indonesia into calcined kaolin phase as precursor in NaY zeolite synthesis. In the calcination process, the kaolinite undergoes phase transformations from metakaolin to mullite. The Bangka kaolin is 74.3% crystalline, predominantly composed of kaolinite, and 25.7% amorphous, with an SiO2/Al2O3 mass ratio of 1.64. Thermal characterization using simultaneous DSC/TGA identified an endothermic peak at 527°C and an exothermic peak at 1013°C. Thus, three calcination temperatures (700, 1013, and 1050 °C) were selected to produce calcined kaolins with different phase distributions. The best product, with 87.8% NaY zeolite in the 54.7% crystalline product and an SiO2/Al2O3 molar ratio of 5.35, was obtained through hydrothermal synthesis using mixed calcined kaolins with a composition of K700C : K1013C : K1050C = 10 : 85 : 5 in %-mass, with seed addition, at a temperature of 93 °Cand a reaction time of 15 hours.
The Influence of PEG400 and Acetone on Polysulfone Membrane Morphology and Fouling Behaviour P.T.P. Aryanti; Shelli R. Joscarita; Anita K. Wardani; S. Subagjo; Danu Ariono; I Gede Wenten
Journal of Engineering and Technological Sciences Vol. 48 No. 2 (2016)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2016.48.2.1

Abstract

Modification of polysulfone ultrafiltration membrane was conducted by blending polysulfone with PEG400 and acetone as additives. The influence of each additive on the resulted membrane morphology and fouling characteristics were investigated. The experimental results showed that the hydrophilicity of the polysulfone membrane was improved by the increase of PEG400 in the polysulfone membrane. The water contact angle of the membrane was decreased from 76.1° to 38.31° when 35 %wt of PEG400 was added into the polysulfone solution, while the water content of the membrane was increased by around 38%. The high concentration of PEG400 in the polysulfone solution led to the formation of longer finger-like cavities in the membrane structure and resulted in a thicker membrane skin layer. The high concentration of PEG400 also contributed to the increase in hydraulic resistance of the membrane due to organic matter fouling. This problem could be minimized by the addition of acetone into the polysulfone solution, which resulted in a lower fouling resistance of organic matter during up to five hours of peat water filtration.
Exceptional Aromatic Distribution in the Conversion of Palm-Oil to Biohydrocarbon Using Zeolite-Based Catalyst I Gusti B. N. Makertihartha; Grandprix Thomryes Mart Kadja; Melia L. Gunawan; Rino R. Mukti; Subagjo Subagjo
Journal of Engineering and Technological Sciences Vol. 52 No. 4 (2020)
Publisher : Institute for Research and Community Services, Institut Teknologi Bandung

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.5614/j.eng.technol.sci.2020.52.4.9

Abstract

A series of four catalysts, i.e. ZSM-5 (Si/Al = 25) (Z1), a combination of ZSM-5 (Si/Al = 25) and zeolite Y (Si/Al = 25) (Z2), zeolite Y (Si/Al = 25) (Z3), and ZSM-5 (Si/Al = 80) (Z4), was successfully prepared for catalytic cracking of palm oil. All three catalysts utilized silica as a binder without other additional components. Catalytic cracking tests showed that the aromatic distribution was very high, according to the following order: Z4 (98%) > Z1 (90%) > Z2 (84%) > Z3 (60%). It was shown that ZSM-5 promotes the formation of aromatics better than zeolite Y does. From 98% of aromatics products in Z1, 71% were benzene, toluene, and xylene (BTX). It appears that the formation of aromatics needs milder acidity since a higher number of acids extends the cracking reaction, resulting in the formation of more gaseous and heavy aromatics products. The results of this study show potential for the sustainable production of bio-hydrocarbons with exceptional aromatic distributions, which may fulfill the demands of the petroleum, petrochemical, and fine chemical sectors.
ISOTHERMAL PYROLYSIS OF KRAFT PULP MILL SLUDGE Syamsudin Syamsudin; Herri Susanto; Subagjo Subagjo
Reaktor Volume 14, No. 4, OKTOBER 2013
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (254.088 KB) | DOI: 10.14710/reaktor.14.4.298-304

Abstract

Kraft pulp mill sludge cake composed of rejected wood fibers and activated sludge microorganisms. With a heating value about 14 MJ/kg (dried basis), this type of biomass had a potential as an alternative energy source. Unfortunately, it had an ash content of 27.6% and a moisture content of 80%. For reducing moisture content with minimum energy consumption, a combination of mechanical dewatering and thermal drying was studied previously. Meanwhile, experiments on isothermal pyrolysis had been carried out for further improvement on ultimate and proximate analysis of solid fuel. Final mass of char obtained from pyrolysis at 500oC was not significantly different from that of 700oC, so pyrolysis was considered to be optimum at 500oC. A char obtained from pyrolysis at temperature of 500oC had a pore surface area of 77.049 m2/g (highest among other temperatures). Kinetic of isothermal pyrolysis was well represented with a first order modified volumetric model with a frequency factor of 0.782 1/s and an activation of 34.050 kJ/mol.
Co-Authors Achmad Syamsul Arief Adnanta Rio Agus Subekti Ahlul Hafizan Resha Anita K. Wardani Anita K. Wardani, Anita K. Danu Ariono Danu Ariono David Bahrin Deviana Pramitasari Endang Sri Rahayu Endar Puspawiningtiyas Fitri Rumiani Galang Putra Persada Hendra Suherman Herri Susanto I Gede Wenten I.G.B Ngurah Makertihartha IGBN Makertihartha IGBN Makertihartha IGBN Makertihartha Kadja, Grandprix Thomryes Marth Kevin R. Lismana Kevin R. Lismana Khasin Fuadi Khasin Fuadi M. Effendy M. Effendy M. Effendy M. Effendy M. Effendy Maria Ulfah Meiti Pratiwi Melia L. Gunawan Melia Laniwati Melia Laniwati Gunawan Melia Laniwati Gunawan Melia Laniwati Gunawan Melia Laniwati Gunawan Mohammad Effendy Mohammad Effendy P.T.P. Aryanti P.T.P. Aryanti, P.T.P. Praharso Paharso Praharso Praharso Pratama Istiadi Rino R. Mukti Shelli R. Joscarita Shelli R. Joscarita, Shelli R. Syamsudin Syamsudin Syamsudin Syamsudin T. Walmiki Samadhi Tatang Hernas Soerawidjaja Temy Nurfahmiawati Tirto Prakoso Tjokorde Walmiki Samadhi Tjokorde Walmiki Samadhi Tjokorde Walmiki Samadhi Tobias Richards Ulfah, Maria Vita Wonoputri Vita Wonoputri Widdy Andya Fanny Winny Wulandari, Winny Yazid Bindar Yazid Bindar Yazid Bindar Yazid Bindar Yogi W. Budhi Yogi W. Budhi Yogi Wibisono Budhi Zaky Al Fatony