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Journal : TEKNIK

UNJUK KERJA REAKTOR PLASMA DIELECTRIC BARRIER DISCHARGE UNTUK PRODUKSI BIODIESEL DARI MINYAK KELAPA SAWIT Yudhistira, Ardian Dwi; Istadi, Istadi
TEKNIK Volume 34, Nomor 2, Tahun 2013
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (352.376 KB) | DOI: 10.14710/teknik.v34i2.5636

Abstract

Biodiesel is one of alternative renewable energy source to substitute diesel fuel. Various biodiesel productionprocesses through transesterification reaction with a variety of catalysts have been developed by previousresearcher. This process still has the disadvantage of a long reaction time, and high energy need. DielectricBarrier Discharge (DBD) plasma electro-catalysis may become a solution to overcome the drawbacks in theconventional transesterification process. This process only needs a short time reaction and low energy process.The purpose of this study was to assess the performance of DBD plasma rector in making biodiesel such as: theeffect of high voltage electric value, electrodes gap, mole ratio of methanol / oil, and reaction time. TheResearch method was using GC-MS (Gas Cromatography-Mass Spectrofotometry) and FTIR (FourierTransform Infrared Spectrofotometry) and then it will be analysed the change of chemical bond betweenreactant and product. So, the reaction mechanism can be predicted. Biodiesel is produced using methanol andpalm oil as reactants and DBD plasma used as reactor in batch system. Then, reactants contacted by highvoltage electric. From the results of this research can be concluded that the reaction mechanism occurs in theprocess is the reaction mechanism of cracking, the higher of electric voltage and the longer of reaction time leadto increasing of product yield. The more of mole ratio of methanol / oil and widening the gap between theelectrodes lead to decreased product yield. From this research, product yield maksimum is 89,8% in the variableof rasio mol metanol/palm oil 3:1, voltage 10 kV, electrode gap 1,5 cm, and reaction time 30 seconds.
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

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.
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.
Back-matter and Author Guidelines Istadi, Istadi
TEKNIK Vol 36, No 1 (2015): (Juli 2015)
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (569.477 KB) | DOI: 10.14710/teknik.v36i1.8756

Abstract

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.
Analysis of CaCO3 Impregnation on HY Zeolite Surface Area, Pore Size, and Activity in the Catalytic Cracking of Palm Oil to Biofuels Rosyad Adrian Febriansyar; Teguh Riyanto; I. Istadi
TEKNIK Vol. 43, No. 1 (2022): Mei 2022
Publisher : Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.14710/teknik.v43i1.44579

Abstract

Fossil energy sources are currently decreasing, requiring the development of alternative energy sources. Vegetable oil is a raw material for alternative renewable energy supplies. This study produced biofuels from vegetable oil using calcium carbonate (CaCO3)-impregnated HY catalysts. In addition, this study aimed to investigate the effect of CaCO3 impregnation on the surface area and the catalytic activity of catalysts in the palm oil cracking process to produce biofuels. The HY catalyst was modified by the wet impregnation method in 5 wt% CaCO3 solution and was further calcined at 550°C for three h. Furthermore, the catalysts were tested in a continuous fixed-bed catalytic reactor at 450°C. The catalyst properties were characterized using Brunauer–Emmett–Teller (BET) surface area, Barrett–Joyner–Halenda (BJH) for pore size distribution, and X-Ray Diffraction (XRD) for crystal structure and phases. The results showed that the addition of CaCO3 decreased surface area and pore volume; however, the pore size increased, which resulted in the production of heavy hydrocarbons. Interestingly, the introduction of CaCO3 enhanced the yield of Organic Liquid Product (OLP) and diesel-range hydrocarbons selectivity to reach 79.09% and 30.54%, respectively. Furthermore, the introduction of CaCO3 increased deoxygenation activity.