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All Journal Reaktor International Journal of Renewable Energy Development TEKNIK Rotasi METANA BERKALA FISIKA JURNAL KIMIA SAINS DAN APLIKASI JURNAL TEKNOLOGI KIMIA DAN INDUSTRI Analisis: Jurnal Studi Keislaman Geoplanning : Journal of Geomatics and Planning Jurnal Riset Pendidikan Matematika Jurnal Riset Industri Mesin JUPE : Jurnal Pendidikan Mandala Universitas Muhammadiyah Yogyakarta Undergraduate Conference Proceeding Jurnal Sosial dan Sains International Journal of Renewable Energy Development Bulletin of Chemical Reaction Engineering & Catalysis Journal of Chemical Engineering Research Progress JURNAL REKAYASA KIMIA & LINGKUNGAN
I. Istadi
Department Of Chemical Engineering, Diponegoro University, Jl. Prof. Soedarto, Kampus UNDIP Tembalang, Semarang 50239
Agriculture, Biological Sciences & Forestry Astronomy Chemical Engineering, Chemistry & Bioengineering Chemistry Civil Engineering, Building, Construction & Architecture Computer Science & IT Control & Systems Engineering Decision Sciences, Operations Research & Management Earth & Planetary Sciences Economics, Econometrics & Finance Education Electrical & Electronics Engineering Energy Engineering Environmental Science Industrial & Manufacturing Engineering Law, Crime, Criminology & Criminal Justice Library & Information Science Materials Science & Nanotechnology Mathematics Mechanical Engineering Physics Public Health Social Sciences

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Mikrostruktur Semikonduktor GaN di Atas Substrat Silikon Dengan Metode Sol-Gel Sutanto, Heri; Nurhasanah, Iis; Istadi, Istadi; Maryanto, Maryanto; Ambikawati, Wahyu; Marlini, Nofi
BERKALA FISIKA Vol 13, No 2 (2010): Berkala Fisika
Publisher : BERKALA FISIKA

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (1874.942 KB)

Abstract

Gallium nitride (GaN) semiconductor thin films have been successfully deposited on Si substrate (004) by sol-gel method. Gel prepared from the crystal gallium-citrate-amines. These crystals formed from a solution containing the ions Ga+3 and citric acid (CA). Gel in place on the substrate and then rotated with a speed of 1100 rpm. The gel layers are obtained and then placed on the programmable furnace. Deposition temperature varied of 800, 900 and 1000oC in a nitrogen gas environment during 2 hour. The crystal quality of GaN thin films have characterized by XRD measurement. The surface morphology and cross section of the films observed by SEM. The film compositions determined by EDX characterization. The results showed that all the GaN thin films on silicon substrate have oriented polycrystalline structure. The crystal quality of GaN film is formed is influenced by the deposition temperature. In a deposition temperature range is used, increasing the deposition temperature can improve the crystal quality of GaN films.   Keywords: GaN Thin Films; Spin-Coating Technique; Silicon Substrate
Effect of Temperature on Plasma-Assisted Catalytic Cracking of Palm Oil into Biofuels Istadi, I.; Riyanto, Teguh; Buchori, Luqman; Anggoro, Didi Dwi; Saputra, Roni Ade; Muhamad, Theobroma Guntur
International Journal of Renewable Energy Development Vol 9, No 1 (2020): February 2020
Publisher : Center of Biomass & Renewable Energy, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/ijred.9.1.107-112

Abstract

Plasma-assisted catalytic cracking is an attractive method for producing biofuels from vegetable oil. This paper studied the effect of reactor temperature on the performance of plasma-assisted catalytic cracking of palm oil into biofuels. The cracking process was conducted in a Dielectric Barrier Discharge (DBD)-type plasma reactor with the presence of spent RFCC catalyst. The reactor temperature was varied at 400, 450, and 500 ºC. The liquid fuel product was analyzed using a gas chromatography-mass spectrometry (GC-MS) to determine the compositions. Result showed that the presenceof plasma and catalytic role can enhance the reactor performance so that the selectivity of the short-chain hydrocarbon produced increases. The selectivity of gasoline, kerosene, and diesel range fuels over the plasma-catalytic reactor were 16.43%, 52.74% and 21.25%, respectively, while the selectivity of gasoline, kerosene and diesel range fuels over a conventional fixed bed reactor was 12.07%, 39.07%, and 45.11%, respectively. The increasing reactor temperature led to enhanced catalytic role of cracking reaction,particularly directing the reaction to the shorter hydrocarbon range. The reactor temperature dependence on the liquid product components distribution over the plasma-catalytic reactor was also studied. The aromatic and oxygenated compounds increased with the reactor temperature.©2020. CBIORE-IJRED. All rights reserved
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.
Reactivation of the Spent Residue Fluid Catalytic Cracking (RFCC) Catalyst through Acid Treatment for Palm Oil Cracking to Biofuels Amalia, Rahma; Riyanto, Teguh; Istadi, Istadi
TEKNIK Vol. 42, No. 2 (2021): August 2021
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/teknik.v42i2.39642

Abstract

This work discusses the treated spent Residue Fluid Catalytic Cracking (RFCC) catalysts using sulfuric or citric acids to examine the impact of acid treatment on the catalyst physicochemical properties and structural characteristics. The catalysts were characterized by X-ray diffraction (XRD), X-ray fluorescence (XRF), and Brunauer−Emmett−Teller-Barrett−Joyner−Halenda (BET-BJH) methods. The catalytsts were performed in a continuous fixed-bed reactor for catalytic cracking of palm oil. Changes of the catalyst characteristics and catalytic performance testing of the catalyst after the acid treatment for palm oil cracking process were discussed. It was found that the acid treatment on the spent RFCC catalyst can increase the surface area and pore volume of catalysts as well as the crystallinity. The closed pores in the spent RFCC are opened by acid treatment by eliminating heavy metals. Concerning to the catalytic performance, the acid-treated catalysts had better performance than the non-treated catalyst, which could increase selectivity of the kerosene-diesel range fraction from 47.89% to 55.41%. It was interested, since the non-treated catalyst could not produce gasoline fraction, while the acid-treated catalsysts could produce gasoline fraction at selectivity range of 0.57 – 0.84%. It was suggested that both sulfuric or citric acids treatment could increase the cracking performance of spent RFCC catalyst by shifting the product to lower hydrocarbons.
PLASTIC WASTE CONVERSION TO LIQUID FUELS OVER MODIFIED-RESIDUAL CATALYTIC CRACKING CATALYSTS: MODELING AND OPTIMIZATION USING HYBRID ARTIFICIAL NEURAL NETWORK – GENETIC ALGORITHM Istadi Istadi; Luqman Buchori; Suherman Suherman
Reaktor Volume 13, Nomor 3, Juni 2011
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (409.398 KB) | DOI: 10.14710/reaktor.13.3.131-139

Abstract

The plastic waste utilization can be addressed toward different valuable products. A promising technology for the utilization is by converting it to fuels. Simultaneous modeling and optimization representing effect of reactor temperature, catalyst calcinations temperature, and plastic/catalyst weight ratio toward performance of liquid fuel production was studied over modified catalyst waste. The optimization was performed to find optimal operating conditions (reactor temperature, catalyst calcination temperature, and plastic/catalyst weight ratio) that maximize the liquid fuel product. A Hybrid Artificial Neural Network-Genetic Algorithm (ANN-GA) method was used for the modeling and optimization, respectively. The variable interaction between the reactor temperature, catalyst calcination temperature, as well as plastic/catalyst ratio is presented in surface plots. From the GC-MS characterization, the liquid fuels product was mainly composed of C4 to C13 hydrocarbons.KONVERSI LIMBAH PLASTIK MENJADI BAHAN BAKAR CAIR DENGAN METODE PERENGKAHAN KATALITIK MENGGUNAKAN KATALIS BEKAS YANG TERMODIFIKASI: PEMODELAN DAN OPTIMASI MENGGUNAKAN GABUNGAN METODE ARTIFICIAL NEURAL NETWORK DAN GENETIC ALGORITHM. Pemanfaatan limbah plastik dapat dilakukan untuk menghasilkan produk yang lebih bernilai tinggi. Salah satu teknologi yang menjanjikan adalah dengan mengkonversikannya menjadi bahan bakar. Permodelan, simulasi dan optimisasi simultan yang menggambarkan efek dari suhu reaktor, suhu kalsinasi katalis, dan rasio berat plastik/katalis terhadap kinerja produksi bahan bakar cair telah dipelajari menggunakan katalis bekas termodifikasi Optimisasi ini ditujukan untuk mencari kondisi operasi optimum (suhu reaktor, suhu kalsinasi katalis, dan rasio berat plastik/katalis) yang memaksimalkan produk bahan bakar cair. Metode Hybrid Artificial Neural Network-Genetic Algorithm (ANN-GA) telah digunakan untuk permodelan dan optimisasi simultan tersebut. Inetraksi antar variabel suhu reaktor, suhu kalsinasi katalis, dan rasio berat plastik/katalis digambarkan dalam bentuk plot surface. Berdasarkan karakterisasi GC-MS, produk bahan bakar yang diperoleh terdiri dari komponen-komponen hidrokarbon C4-C13.
APLICATION OF CATALYTIC DIELECTRIC BARRIER DISCHARGE PLASMA REACTOR FOR CO-GENERATION OF SYNTHESIS GAS AND HIGHER HYDROCARBONS istadi istadi; Amin N.A.S. Amin
Reaktor Volume 10 No. 1 Juni 2006
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/reaktor.10.1.17-23

Abstract

This paper deals with potential application of hybrid catalytic DBD plasma reaktor for the co-generation of  C2 hydrocarbons and synthesis gases from methane and carbon dioxide. The synergism of the catalyst, feed ratio and the plasma discharge affect the products, distribution, particularly C2 hydrocarbons selectivity . The CH,CO2 feed ratio total feed flow rate, and the discharge voltage incatalytic BDB plasma reactor systems shoe significant effects on the reactor performances. However increasing the reactor wall temperature has no apparent influence on the selectivity to C2 hydrocarbons and hydrogen within the investigated range. The hybrid catalytic DBD plasma rectorwas more suitable for CO2OCM process than the conventional catalytic reactor over CaO-MnO/CeO2catalyst
STUDI REAKTOR PLASMA DIELECTRIC BARRIER DISCHARGE (DBD) PLANAR TO PLANAR UNTUK PRE-TREATMENT KONVERSI LIMBAH PLASTIK POLIPROPILEN MENJADI BAHAN BAKAR CAIR Aniyati Khoiriyah; M.C.T. Wahyu Utami; I. Istadi
JURNAL TEKNOLOGI KIMIA DAN INDUSTRI Volume 1, Nomor 1, Tahun 2012
Publisher : Jurusan Teknik Kimia, Fakultas Teknik, Universitas Diponegoro,

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (251.212 KB)

Abstract

Polipropilen (PP) is a kind of plastic that is widely used in our life. Plastic wastes give big problems to environment because plastic wastes are not easily degraded by nature. Conventional method for plastic waste processing is thermal cracking and catalytic cracking. The conventional process needs high energy. Plasma technology combined with catalytic cracking process is expected to cover the problems of energy requirement. Distance between both electrodes (high voltage and ground) and high voltage magnitude in plasma reactor is important parameter in plasma reactor operation and type or design of plasma reactor. Optimum of both important parameters need to be studied in order to get optimal operating condition suitable for better productivity. DBD Planar to Planar plasma reactor can be used to pre-crack polipropilen's structure (in the pre-treatment's process) so that catalytic cracking process in fixed bed's reactor conventional that use RCC (Residual Catalytic Cracking) catalyst can be easier to take. On this plasma reactor, distance between both electrodes of 2,5 - 4 cm, and the high voltage of 3-7,5 kV are optimal operating conditions. Combination of the pre-treatment (distance between electrodes 3,3 cm and high voltage 5,3 kV) and  the conventional catalytic cracking process by using weight ratio of catalyst to plastic 2:1 and reactor temperature 500oC and reaction time 1 hour could produce liquid fuel yield of 36,27%.
PEMBUATAN DAN KARAKTERISASI KATALIS HETEROGEN SO 2- - ZnO DAN SO42- / ZnO DENGAN METODE KOPRESIPITASI DAN IMPREGNASI UNTUK PRODUKSI BIODIESEL DARI MINYAK KEDELAI D. A. Rahmawati; D. Intaningrum; Istadi Istadi
JURNAL TEKNOLOGI KIMIA DAN INDUSTRI Volume 2, Nomor 4, Tahun 2013
Publisher : Jurusan Teknik Kimia, Fakultas Teknik, Universitas Diponegoro,

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Abstract

In this reasearch focuses on the physical and chemical 2- characterization of 2- sulfated zinc oxide catalyst SO4 - ZnO with coprecipitation method and SO4 / ZnO impregnation method. The purpose of this study is to prepare the ZnO-based acid catalyst, to determine the characteristics of the catalyst, and the catalyst testin on biodiesel production from soybean oil. The characterization was conducted using X-ray diffraction (XRD) to determine the catalyst morphology and Fourier Transform-Infra Red (FT-IR) to determine the structure of chemical bonds are formed. Identification of the content and composition of biodiesel, mainly on the composition of Fatty Acid Methyl Ester (FAME), were analyzed by GC-MS and by FT-IR. Meanwhile the heat content of the products of 2- biodiesel calorific value is measured. Results of the characterization showe that the SO4 2- - ZnO catalyst has a stronger acidity and higher catalyst activity than acidic SO4 / ZnO catalysts. In the catalyst testing for the transesterification process, the SO42--ZnO catalyst showed the biodiesel yield of 80.19%.
SINTESA KATALIS SUPER ASAM SO42-/ ZnO UNTUK PRODUKSI BIODIESEL DARI MINYAK KELAPA SAWIT Inshani Utami; Roikhatus Solikhah; I. Istadi
JURNAL TEKNOLOGI KIMIA DAN INDUSTRI Volume 1, Nomor 1, Tahun 2012
Publisher : Jurusan Teknik Kimia, Fakultas Teknik, Universitas Diponegoro,

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (150.104 KB)

Abstract

The issue of energy is a global issue that must be discussed by all countries in the world. Rising oil prices and a dwindling supply push every country to develop new renewable energy alternatives. One of this alternative energy is biodiesel. The biodiesel production can be done by using vegetable oil as the raw material over supported homogeneous catalyst, heterogeneous catalyst and enzymatic catalyst. In this study the use of palm oil as the main material to be reacted with methanol and the catalyst used as heterogeneous catalysts SO42-/ZnO by changing variables used are long reaction times (1, 2.5 and 4 hours) and the weight ratio of catalyst / oil (4 , 6, and 8).The studybeganwith thepreparation of catalyst SO42-/ZnO followed by aransesterification reaction between palm oil with methanol. The resultsofthis studyshowed that the super acid catalyst SO42-/ZnOcan be usedin making biodiesel.Optimum operatingcondition for this catalytic reaction is the weight ratio of catalyst/oil 3,8 during 2,5 hours with 78%  yield of the resulting ester metal.Longer time ofthe transesterificationreaction, the higher the % yield ofthe resulting ester metal, while adding more catalyst produced the lower theyield.
Kinetika Reaksi Transesterifikasi Minyak Kedelai Menjadi Biodiesel dengan Katalis CaO Setiarto Pratigto; Istadi Istadi
Jurnal Kimia Sains dan Aplikasi Vol 22, No 5 (2019): Volume 22 Issue 5 Year 2019
Publisher : Chemistry Department, Faculty of Sciences and Mathematics, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2634.923 KB) | DOI: 10.14710/jksa.22.5.213-219

Abstract

The use of biodiesel is expected to reduce dependence on fossil fuels. In this study, the kinetic reaction of transesterification of soybean oil with methanol will be assessed using heterogeneous CaO solid base catalyst with parameters of mole ratio of reactants to the conversion of methyl ester used to determine the reaction velocity equation. The reaction speed equation is used in the design of a fluidized CSTR (Continues Tank Reactor) reactor to obtain the reactor volume and catalyst weight. The purpose of this study was to determine the form of the velocity reaction equation for soybean and methanol transesterification reactions using CaO catalyst and determine the weight of the catalyst needed by using the reaction speed equation. The study was carried out by transesterification of soybean oil and methanol with CaO catalyst with the independent variable mole ratio of reactants while the fixed variable reaction temperature was 60°C, catalyst weight was 3% (% b/v), reaction time was 180 minutes. The results showed that methanol adsorbed on the surface of the catalyst and triglycerides not adsorbed on the surface of the catalyst showed that the mechanism of the catalytic reaction that occurred was the Eley-Rideal mechanism where one of the reactants was adsorbed on the surface of the catalyst. The form of the speed equation for the transesterification reaction of soybean oil and methanol using a CaO catalyst is  . The reaction speed equation is used in the design of the reactor, so that the relationship between the weight of the catalyst needed to convert triglycerides to biodiesel and the predicted calculation of the volume of the reactor used can be done.
Co-Authors Afriadie, Chandra Ajeng Riswanti Wulandari Alqurni, Wais Amin N.A.S. Amin Amin Nugroho Aminuyati Anggun Kurniawan Anindita Indriana Aniyati Khoiriyah Anwar Muttaqien, Anwar Anwaruddin Hisyam Anwaruddin Hisyam Ardian D. Yudhistira Ardian Dwi Yudhistira Aribowo, Windarto Astri Rakhmawati Atanasius Priharyoto Bayuseno Bahrudin, Moh. Bambang Pramudono Bambang Tri Nugroho Bintang Ayu Kalimantini Chusnul Khotimah D. A. Rahmawati D. Intaningrum Daniel Setiyo Nugroho Daniel Setiyo Nugroho, Daniel Setiyo Dian Rahmayanti Didi D. Anggoro Didi D. Anggoro Didi D. Anggoro Didi D. Anggoro Didi Dwi Anggoro Dinara, Daniella Cipta Dini Wulandari Dorothy Hoo Wei Ling Dyah Hesti Wardhani Eko Hidayanto Fachmy Adji Pangestu Setiawan Fajar Astuti Febriansyar, Rosyad Adrian Haniif Prasetiawan Heri Mulyanti Heri Sutanto Herlina Hidayati Iis Nurhasanah Inshani Utami Inshani Utami Karimullah, Suud Sarim Kursius, Catherine M. Kursius, Catherine Mentaya Luqman Buchori M.C.T. Wahyu Utami Maryanto - Muhamad, Theobroma Guntur Nani Harihastuti, Nani New Pei Yee Nofi Marlini Nor Aishah Saidina Amin Nor Aishah Saidina Amin Nor Aishah Saidina Amin P Purwanto Pakpahan, Agnes J. Pakpahan, Andre W. S. Permatasari, Astrid Eka Pratiwi, A. Andini Radisya Purwanto . Purwanto Purwanto Purwanto Purwanto Putut Marwoto Qotrunnada, Novaya Aulia Rahma Amalia Rahmat Gernowo Ratna Dewi Kusumaningtyas Riyanto, Teguh Roikhatus Solikhah Roikhatus Solikhah Salsabila, Unik Hanifah Salsabilla, Alda Saputra, Roni Ade Sitompul, J. P Slamet Priyanto Suherman Suherman Sulistyo Sulistyo Teguh Riyanto Teuku Irfan Maulana Udin Mabruro Wahyu Ambikawati Wulandari, Ajeng Riswanti