I. Istadi
Department of Chemical Engineering, Faculty of Engineering, Diponegoro University Jl. Prof. Soedarto, SH, Kampus Undip Tembalang, Semarang 50275

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Ucapan Terima Kasih kepada Mitra Bebestari (Reviewer) Istadi, Istadi
TEKNIK Vol 35, No 1 (2014): (July 2014)
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (71.967 KB) | DOI: 10.14710/teknik.v35i1.7680

Abstract

Author Guidelines 2013 Istadi, Istadi
Bulletin of Chemical Reaction Engineering & Catalysis 2013: BCREC Volume 8 Issue 1 Year 2013 (SCOPUS Indexed, June 2013)
Publisher : Department of Chemical Engineering - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (477.109 KB) | DOI: 10.9767/bcrec.8.1.5106.App.1-4

Abstract

DOI: 10.9767/bcrec.8.1.5106.App.1-4 
Biofuels Production from Catalytic Cracking of Palm Oil Using Modified HY Zeolite Catalysts over A Continuous Fixed Bed Catalytic Reactor Istadi, I.; Riyanto, Teguh; Buchori, Luqman; Anggoro, Didi D.; Pakpahan, Andre W. S.; Pakpahan, Agnes J.
International Journal of Renewable Energy Development Vol 10, No 1 (2021): February 2021
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.2021.33281

Abstract

The increase in energy demand led to the challenging of alternative fuel development. Biofuels from palm oil through catalytic cracking appear as a promising alternative fuel. In this study, biofuel was produced from palm oil through catalytic cracking using the modified HY zeolite catalysts. The Ni and Co metals were impregnated on the HY catalyst through the wet-impregnation method. The catalysts were characterized using X-ray fluorescence, X-ray diffraction, Brunauer–Emmett–Teller (BET), Pyridine-probed Fourier-transform infrared (FTIR) spectroscopy, and Scanning Electron Microscopy (SEM) methods. The biofuels product obtained was analyzed using a gas chromatography-mass spectrometry (GC-MS) method to determine its composition. The metal impregnation on the HY catalyst could modify the acid site composition (Lewis and Brønsted acid sites), which had significant roles in the palm oil cracking to biofuels. Ni impregnation on HY zeolite led to the high cracking activity, while the Co impregnation led to the high deoxygenation activity. Interestingly, the co-impregnation of Ni and Co on HY catalyst could increase the catalyst activity in cracking and deoxygenation reactions. The yield of biofuels could be increased from 37.32% to 40.00% by using the modified HY catalyst. Furthermore, the selectivity of gasoline could be achieved up to 11.79%. The Ni and Co metals impregnation on HY zeolite has a promising result on both the cracking and deoxygenation process of palm oil to biofuels due to the role of each metal. This finding is valuable for further catalyst development, especially on bifunctional catalyst development for palm oil conversion to biofuels.
PERMODELAN DAN OPTIMASI HIDROLISA PATI MENJADI GLUKOSA DENGAN METODE ARTIFICIAL NEURAL NETWORK - GENETIC ALGORITHM Istadi, Istadi; Rahmayanti, Dian
TEKNIK Volume 31, Nomor 2, Tahun 2010
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (798.394 KB) | DOI: 10.14710/teknik.v31i2.1767

Abstract

Modeling and optimization methods are commonly used, still not able to model and optimize the complexchemical processes non-linear. Hybrid method of Artificial Neural Network-Genetic Algorithm (ANN-GA) isconsidered as an effective method for resolving these problems and obtain optimum conditions globally. Theaim of this study is to develop a modeling and optimization with hybrid ANN-GA methods, which applied inprocess of making glucose from starch hydrolysis. The ANN-GA stategy consists of two steps. In the first step,an ANN-based prosess model is developed. Therefore, the input at ANN model will be optimized using GAtechnique. The optimal values of starch concentration, enzyme concentration, temperature and time with ANNGAmethod were 7,13 % (w/v), 1,47 %(w/v), 40,53ºC, and 166,04 min respectively with predicted glucose yieldof 6,08 mg/mL. These result differed from the secondary data (Baskar et al., 2008) which were used RSM. Itwas because R2 values of ANN-GA method was 0,9755. While RSM method was only able to achieved value ofR2 for 0,842. Modeling and optimization with the GA-ANN can be developed and used to obtain the model instarch hydrolysis into glucose and the optimal operating conditions simultaneouosly.
International Editorial Boards Istadi, Istadi
Bulletin of Chemical Reaction Engineering & Catalysis 2012: BCREC Volume 7 Issue 2 Year 2012 (SCOPUS Indexed)
Publisher : Department of Chemical Engineering - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (106.342 KB) | DOI: 10.9767/bcrec.7.2.4365.i

Abstract

http://dx.doi.org/10.9767/bcrec.7.2.4365.i 
Indexing and Abstracting Istadi, Istadi
Bulletin of Chemical Reaction Engineering & Catalysis 2013: BCREC Volume 8 Issue 2 Year 2013 (SCOPUS Indexed, December 2013)
Publisher : Department of Chemical Engineering - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (105.274 KB) | DOI: 10.9767/bcrec.8.2.5842.iii

Abstract

Author Guidelines (2012 Version) Istadi, Istadi
Bulletin of Chemical Reaction Engineering & Catalysis 2013: BCREC Volume 7 Issue 3 Year 2013 (SCOPUS Indexed, March 2013)
Publisher : Department of Chemical Engineering - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (476.688 KB) | DOI: 10.9767/bcrec.7.3.4550.App.1-4

Abstract

http://dx.doi.org/10.9767/bcrec.7.3.4550.App.1-4
Catalytic-Dielectric Barrier Discharge Plasma Reactor For Methane and Carbon Dioxide Conversion Istadi, Istadi; Saidina Amin, Nor Aishah
Bulletin of Chemical Reaction Engineering & Catalysis 2007: BCREC: Volume 2 Issues 2-3 Year 2007
Publisher : Department of Chemical Engineering - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (38.372 KB) | DOI: 10.9767/bcrec.2.2-3.8.37-44

Abstract

A catalytic - DBD plasma reactor was designed and developed for co-generation of synthesis gas and C2+ hydrocarbons from methane. A hybrid Artificial Neural Network - Genetic Algorithm (ANN-GA) was developed to model, simulate and optimize the reactor. Effects of CH4/CO2 feed ratio, total feed flow rate, discharge voltage and reactor wall temperature on the performance of catalytic DBD plasma reactor was explored. The Pareto optimal solutions and corresponding optimal operating parameters ranges based on multi-objectives can be suggested for catalytic DBD plasma reactor owing to two cases, i.e. simultaneous maximization of CH4 conversion and C2+ selectivity, and H2 selectivity and H2/CO ratio. It can be concluded that the hybrid catalytic DBD plasma reactor is potential for co-generation of synthesis gas and higher hydrocarbons from methane and carbon dioxide and showed better than the conventional fixed bed reactor with respect to CH4 conversion, C2+ yield and H2 selectivity for CO2 OCM process. © 2007 BCREC UNDIP. All rights reserved.[Presented at Symposium and Congress of MKICS 2007, 18-19 April 2007, Semarang, Indonesia][How to Cite: I. Istadi, N.A.S. Amin. (2007). Catalytic-Dielectric Barrier Discharge Plasma Reactor For Methane and Carbon Dioxide Conversion. Bulletin of Chemical Reaction Engineering and Catalysis, 2 (2-3): 37-44.  doi:10.9767/bcrec.2.2-3.8.37-44][How to Link/DOI: http://dx.doi.org/10.9767/bcrec.2.2-3.8.37-44 || or local: http://ejournal.undip.ac.id/index.php/bcrec/article/view/8][Cited by: Scopus 1 | ]
Karakterisasi Katalis CaO dan Uji Aktivitas pada Kinetika Reaksi Transesterifikasi Minyak Kedelai Pratigto, Setiarto; Istadi, Istadi; Wardhani, Dyah Hesti
METANA Vol 15, No 2 (2019): Desember 2019
Publisher : Universitas Diponegoro

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1178.735 KB) | DOI: 10.14710/metana.v15i2.25106

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Penelitian ini akan mengkaji kinetika reaksi transesterifikasi minyak kedelai dengan metanol menggunakan katalis CaO dengan parameter rasio mol reaktan terhadap konversi metil ester yang digunakan untuk menentukan persamaan kecepatan reaksi. Katalis CaO digunakan untuk reaksi transesterifikasi karena memiliki kekuatan basa yang tinggi, ramah lingkungan, kelarutan yang rendah dalam metanol. Kinetika reaksi untuk reaktor batch dihitung saat reaksi berlangsung berdasarkan rejim surface area limited yang menentukan. Tujuan penelitian ini untuk mengetahui bentuk persamaan kecepatan reaksi transesterifikasi minyak kedelai dan metanol menggunakan katalis CaO menurut metode differential reactor. Penelitian dilakukan dengan reaksi transesterifikasi minyak kedelai dan metanol dengan katalis CaO dengan variabel bebas perbandingan mol reaktan. Hasil penelitian mengemukakan metanol teradsorpsi di permukaan katalis dan trigliserida tidak teradsorpsi di permukaan katalis menunjukkan mekanisme reaksi katalitik Eley-Rideal. Persamaan kecepatan reaksi dapat digunakan dalam perancangan reaktor, sehingga hubungan antara konversi trigliserida menjadi biodiesel dengan kebutuhan berat katalis dan volume reaktor yang diperlukan dapat diprediksi. This study will examine the kinetics of the transesterification reaction of soybean oil with methanol using a CaO catalyst with the parameters of the mole ratio of reactants to the conversion of methyl esters used to determine the reaction velocity equation. CaO catalyst is used for transesterification reaction because it has high base strength, environmentally friendly, low solubility in methanol. The reaction kinetics for a batch reactor are calculated when the reaction takes place based on a decisive surface area limited regime. The purpose of this study was to determine the shape of the speed equation for the transesterification of soybean oil and methanol using a CaO catalyst according to the differential reactor method. The research was carried out with the transesterification reaction of soybean oil and methanol with a CaO catalyst with a free variable ratio of reactant moles. The results of the study revealed that methanol adsorbed on the surface of the catalyst and triglycerides not adsorbed on the surface of the catalyst showed an Eley-Rideal catalytic reaction mechanism. The reaction speed equation can be used in reactor design, so the relationship between the conversion of triglycerides to biodiesel with the required catalyst weight and the reactor volume required can be predicted.
Kinetika Reaksi Transesterifikasi Minyak Kedelai Menjadi Biodiesel Menggunakan Katalis Padat Ramah Lingkungan K2O/CaO-ZnO Aribowo, Windarto; Nugroho, Amin; Istadi, I.
TEKNIK Vol 40, No. 3 (2019): Desember 2019
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (387.897 KB) | DOI: 10.14710/teknik.v40i3.24080

Abstract

Katalis padat yang ramah lingkungan K2O/CaO-ZnO memiliki keunggulan untuk proses reaksi transesterifikasi meliputi sifat basa heterogen aktif, kelarutan rendah, kekuatan mekanik yang baik, dan dapat digunakan kembali. Penelitian ini bertujuan untuk mengkaji kinetika reaksi transesterifikasi minyak kedelai menjadi biodiesel menggunakan katalis padat K2O/CaO-ZnO untuk mendapatkan model persamaan laju reaksi heterogen. Kajian meliputi: prediksi mekanisme yang sesuai dengan data eksperimen melalui analisis ketergantungan perubahan laju reaksi terhadap perubahan masing-masing reaktan dan perumusan persamaan akhir laju reaksi. Persamaan laju reaksi yang dihasilkan dapat dipakai untuk perancangan reaktor. Hasil kajian menunjukkan bahwa mekanisme reaksi yang terjadi mengikuti mekanisme Eley-Rideal, dimana metanol yang teradsorpsi pada permukaan katalis bereaksi dengan trigliserida (minyak kedelai) pada fase cairnya menghasilkan biodiesel (fatty acid methyl ester) dan gliserol. Persamaan laju reaksi yang diperoleh digunakan dalam perancangan reaktor sehingga hubungan antara berat katalis yang dibutuhkan dengan konversi trigliserida menjadi biodiesel dan perhitungan volume reaktor yang dibutuhkan dapat dilakukan.