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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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Advanced Chemical Reactor Technologies for Biodiesel Production from Vegetable Oils - A Review Luqman Buchori; Istadi Istadi; Purwanto Purwanto
Bulletin of Chemical Reaction Engineering & Catalysis 2016: BCREC Volume 11 Issue 3 Year 2016 (December 2016)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.11.3.490.406-430

Abstract

Biodiesel is an alternative biofuel that can replace diesel oil without requiring modifications to the engine and advantageously produces cleaner emissions. Biodiesel can be produced through transesterification process between oil or fat and alcohol to form esters and glycerol. The transesterification can be carried out with or without a catalyst. The catalyzed production of biodiesel can be performed by using homogeneous, heterogeneous and enzyme. Meanwhile, non-catalytic transesterification with supercritical alcohol provides a new way of producing biodiesel. Microwave and ultrasound assisted transesterification significantly can reduce reaction time as well as improve product yields. Another process, a plasma technology is promising for biodiesel synthesis from vegetable oils due to very short reaction time, no soap formation and no glycerol as a by-product. This paper reviews briefly the technologies on transesterification reaction for biodiesel production using homogeneous, heterogeneous, and enzyme catalysts, as well as advanced methods (supercritical, microwave, ultrasonic, and plasma technology). Advantages and disadvantages of each method were described comprehensively.
Preliminary Testing of Hybrid Catalytic-Plasma Reactor for Biodiesel Production Using Modified-Carbon Catalyst Luqman Buchori; Istadi Istadi; Purwanto Purwanto; Anggun Kurniawan; Teuku Irfan Maulana
Bulletin of Chemical Reaction Engineering & Catalysis 2016: BCREC Volume 11 Issue 1 Year 2016 (April 2016)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.11.1.416.59-65

Abstract

Preliminary testing of hybrid catalytic-plasma reactor for biodiesel production through transesterification of soybean oil with methanol over modified-carbon catalyst was investigated. This research focused on synergetic roles of non-thermal plasma and catalysis in the transesterification process. The amount of modified-carbon catalyst with grain size of 1.75 mm was placed into fixed tubular reactor within discharge zone. The discharge zone of the hybrid catalytic-plasma reactor was defined in the volume area between high voltage and ground electrodes. Weight Hourly Space Velocity (WHSV) of 1.85 h-1 of reactant feed was studied at reaction temperature of 65 oC and at ambient pressure. The modified-carbon catalyst was prepared by impregnation of active carbon within H2SO4 solution followed by drying at 100 oC for overnight and calcining at 300 oC for 3 h. It was found that biodiesel yield obtained using the hybrid catalytic-plasma reactor was 92.39% and 73.91% when using active carbon and modified-carbon catalysts, respectively better than without plasma. Therefore, there were synergetic effects of non-thermal plasma and catalysis roles for driving the transesterification process. 
Effects of Weight Hourly Space Velocity and Catalyst Diameter on Performance of Hybrid Catalytic-Plasma Reactor for Biodiesel Synthesis over Sulphated Zinc Oxide Acid Catalyst Luqman Buchori; Istadi Istadi; Purwanto Purwanto
Bulletin of Chemical Reaction Engineering & Catalysis 2017: BCREC Volume 12 Issue 2 Year 2017 (August 2017)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.12.2.775.227-234

Abstract

Biodiesel synthesis through transesterification of soybean oil with methanol on hybrid catalytic-plasma reactor over sulphated zinc oxide (SO42-/ZnO) active acid catalyst was investigated. This research was aimed to study effects of Weight Hourly Space Velocity (WHSV) and the catalyst diameter on performance of the hybrid catalytic-plasma reactor for biodiesel synthesis. The amount (20.2 g) of active sulphated zinc oxide solid acid catalysts was loaded into discharge zone of the reactor. The WHSV and the catalyst diameter were varied between 0.89 to 1.55 min-1 and 3, 5, and 7 mm, respectively. The molar ratio of methanol to oil as reactants of 15:1 is fed to the reactor, while operating condition of the reactor was kept at reaction temperature of 65 oC and ambient pressure. The fatty acid methyl ester (FAME) component in biodiesel product was identified by Gas Chromatography - Mass Spectrometry (GC-MS). The results showed that the FAME yield decreases with increasing WHSV. It was found that the optimum FAME yield was achieved of 56.91 % at WHSV of 0.89 min-1 and catalyst diameter of 5 mm and reaction time of 1.25 min. It can be concluded that the biodiesel synthesis using the hybrid catalytic-plasma reactor system exhibited promising the FAME yield. 
Effects of Ion Exchange Process on Catalyst Activity and Plasma-Assisted Reactor Toward Cracking of Palm Oil into Biofuels Istadi Istadi; Luqman Buchori; Didi Dwi Anggoro; Teguh Riyanto; Anindita Indriana; Chusnul Khotimah; Fachmy Adji Pangestu Setiawan
Bulletin of Chemical Reaction Engineering & Catalysis 2019: BCREC Volume 14 Issue 2 Year 2019 (August 2019)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.14.2.4257.459-467

Abstract

Biofuels can be produced through a conventional catalytic cracking system and/or a hybrid catalytic-plasma cracking system. This paper was focused on studying effect of Na+ ion exchange to HY-Zeolite catalyst on catalyst performance to convert palm oil into biofuels over a conventional continuous fixed bed catalytic cracking reactor and comparing the catalytic cracking performance when carried out in a continuous hybrid catalytic-plasma reactor. The catalysts were characterized by X-ray Diffraction (XRD) and Bruneuer-Emmet-Teller (BET) surface area methods. The biofuels product were analyzed using Gas Chromatography-Mass Spectrometry (GC-MS) to determine the hydrocarbons composition of biofuels product. From the results, ion exchange process of Na+ into HY-Zeolite catalyst decreases the catalyst activity due to decreasing the number of active sites caused by blocking of Na+ ion. The selectivity to gasoline ranges achieved 34.25% with 99.11% total conversion when using HY catalyst over conventional continuous fixed bed reactor system. Unfortunately, the selectivity to gasoline ranges decreased to 13.96% and the total conversion decrease slightly to 98.06% when using NaY-Zeolite catalyst. As comparison when the cracking reaction was carried out in a hybrid catalytic-plasma reactor using a spent residual catalytic cracking (RCC) catalyst, the high energetics electron from plasma can improve the reactor performance, where the conversion and yield were increased and the selectivity to lower ranges of hydrocarbons was increased. However, the last results were potential to be intensively studied with respect to relation between reactor temperature and plasma-assisted catalytic reactor parameters. Copyright © 2019 BCREC Group. All rights reserved 
Reusability and Stability Tests of Calcium Oxide Based Catalyst (K2O/CaO-ZnO) for Transesterification of Soybean Oil to Biodiesel Istadi Istadi; Udin Mabruro; Bintang Ayu Kalimantini; Luqman Buchori; Didi Dwi Anggoro
Bulletin of Chemical Reaction Engineering & Catalysis 2016: BCREC Volume 11 Issue 1 Year 2016 (April 2016)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.11.1.413.34-39

Abstract

This paper was purposed for testing reusability and stability of calcium oxide-based catalyst (K2O/CaO-ZnO) over transesterification reaction of soybean oil with methanol to produce biodiesel. The K2O/CaO-ZnO catalyst was synthesized by co-precipitation method of calcium and zinc nitrates followed by impregnation of potassium nitrate. The fresh and used catalysts were tested after regeneration. The catalysts were characterized by Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD), and BET Surface Area in order to compare the catalyst structure between the fresh and used catalysts. The catalyst testing in transesterification proses was carried out at following operating conditions, i.e. catalyst weight of 6 wt.%, oil to methanol mole ratio of 1:15, and temperature of 60 oC. In addition, metal oxide leaching of K2O/CaO-ZnO catalyst during reaction was also tested. From the results, the catalysts exhibited high catalytic activity (80% fatty acid methyl ester (FAME) yield after three-cycles of usage) and acceptable reusability after regeneration. The catalyst also showed acceptable stability of catalytic activity, even after three-cycles of usage. 
Assessing Vulnerability of Agriculture to Drought in East Java, Indonesia: Application of GIS and AHP Mulyanti, Heri; Istadi, Istadi; Gernowo, Rahmat
Geoplanning: Journal of Geomatics and Planning Vol 10, No 1 (2023)
Publisher : Department of Urban and Regional Planning, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/geoplanning.10.1.55-72

Abstract

Drought known as ‘silent killer’—unpredictable slow-moving hazard which cause severe damage to people and environment. Since agriculture is the first and foremost sector affected by drought, the risk of crop failure can be minimized by reducing vulnerability. Climate patterns can be considered as systematic conditions which are capable of assigning sensitivity regions to drought. Here, the study employs Oldeman’s Agro Climatic data as physical vulnerability indicator to assess and monitor the vulnerability of agriculture system to drought in East Java. The study used long-term monthly rainfall observation data to generate climatic map accompanied with socio-economic indicators to assess vulnerability of region to drought. Spatial distribution of vulnerability was mapped using Geographic Information Systems (GIS) combined with Analytic Hierarchy Process (AHP). The results show there are five categories of vulnerability to drought: very high, high, moderate, low, and very low based on standardized index. Madura Island, particularly Bangkalan, Sampang, and Sumenep considered as most vulnerable region to drought. In addition, most regions in the north plain of East Java, including Tuban, Lamongan, and Gresik categorized as highly vulnerable to drought. Factors affecting vulnerability are mostly related to drier climate which affect acreage and availability of irrigation. The socio-economic factors likewise smallholder farmers and poverty contribute to rising vulnerability level. South part of East Java, particularly Tulungagung and Blitar Regency was least vulnerable because of appropriate climate which induced to acreage of irrigated land. The study emphasizes the utilizing of Oldeman climate pattern as primary indicator in determining vulnerable regions. Smallholder farmers and poverty causing vulnerability in agriculture emerged as priority for further study. The results can provide new insights into drought management for most vulnerable regions by considering local climatic characteristics.
Backmatter (Publication Ethics, Copyright Transfer Agreement for Publishing Form) Istadi, Istadi
Bulletin of Chemical Reaction Engineering & Catalysis 2024: BCREC Volume 19 Issue 1 Year 2024 (April 2024)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20135

Abstract

Backmatter (Publication Ethics, Copyright Transfer Agreement for Publishing Form)
Backmatter (Publication Ethics, Copyright Transfer Agreement for Publishing Form) Istadi, Istadi
Bulletin of Chemical Reaction Engineering & Catalysis 2024: BCREC Volume 19 Issue 2 Year 2024 (August 2024)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.20184

Abstract

Backmatter (Publication Ethics, Copyright Transfer Agreement for Publishing Form)
The use of artificial intelligence in numerical learning of geometry for students with mild intellectual disabilities Wulandari, Dini; Istadi, Istadi; Muttaqien, Anwar
Proceedings of Universitas Muhammadiyah Yogyakarta Graduate Conference Vol. 4 No. 1 (2024): Renewable Energy, Environment, and Technology for Sustainable Transformation
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/umygrace.v4i1.662

Abstract

Education is very important nowadays. Education plays an important role in improving human resources. Children are asked to be able to understand various sciences well, one of which is geometry in mathematics lessons. However, there are still many children who have difficulty getting a decent education, especially children with intellectual disabilities. This article aims to review effective learning methods for students with intellectual disabilities in understanding geometric material and being able to apply it in solving problems in real life contexts. One branch of mathematics that needs to be studied in depth is geometry. Since childhood, we have started to recognize objects that actually use geometric shapes. These objects are even simple objects that we often encounter around us. Apart from knowing the shapes and formulas in geometry, we are also expected to be able to apply geometry in everyday life. Students with intellectual disabilities are expected to have numerical abilities in solving geometry problems. This research uses a qualitative descriptive method by describing and analyzing data related to the discussion. Students with intellectual disabilities need learning media that can be more interactive and can increase understanding and creativity in thinking. By using artificial intelligence teachers can develop more effective learning media for students.
Metaphorical Thinking Approach as a Strategy for Solving Algebraic Problems in the Daily Life of Phase D Students in Mathematics Learning Kursius, Catherine Mentaya; Istadi, Istadi; Muttaqien, Anwar
Proceedings of Universitas Muhammadiyah Yogyakarta Graduate Conference Vol. 4 No. 1 (2024): Renewable Energy, Environment, and Technology for Sustainable Transformation
Publisher : Universitas Muhammadiyah Yogyakarta

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.18196/umygrace.v4i1.663

Abstract

The Metaphorical Thinking approach in learning mathematics algebra material in the Independent Curriculum provides students with a more meaningful experience of the understanding process because they can see, form and map mathematical concepts to experiential concepts to practice solving everyday life problems in Algebraic form. This research is a library research study supported by interviews at SMP Negeri 3 Sampit. The research was carried out by collecting data from various sources regarding the difficulties of Phase D (SMP) students in algebra material and the metaphorical thinking approach to see the achievement of meaningful understanding of mathematics. With the characteristics of Metaphorical Thinking, students can carry out mathematical problem-solving activities, especially algebraic mathematical problems, so as to find meaningful understanding. Then carry out data analysis using descriptive analysis to determine the effect of the metaphorical thinking approach on the daily life problem solving abilities of phase D students in algebra material.
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