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All Journal International Journal of Advances in Applied Sciences Reaktor Prosiding Seminar Nasional Sains Dan Teknologi Fakultas Teknik Journal Of Chemical Process Engineering (JCPE) Abdimas Umtas : Jurnal Pengabdian kepada Masyarakat Abdimas: Jurnal Pengabdian Masyarakat Universitas Merdeka Malang REACTOR : Journal of Research On Chemistry And Engineering

Megawati Megawati

D3 Teknik Kimia, Fakultas Teknik, Universitas Negeri Semarang Gedung E1, Kampus Sekaran, Gunung Pati, Semarang 50229

Author-ID : 2956418

Religion Aerospace Engineering Agriculture, Biological Sciences & Forestry Arts Humanities Biochemistry, Genetics & Molecular Biology Chemical Engineering, Chemistry & Bioengineering Chemistry Computer Science & IT Control & Systems Engineering Earth & Planetary Sciences Education Energy Engineering Environmental Science Materials Science & Nanotechnology Mathematics Physics Social Sciences

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The Kinetics of Calcium Oxide Catalyzed Esterification of Glycerol with Free Fatty Acids Using Pseudo-homogeneous Model Approach Megawati Megawati; Dhoni Hartanto; Catur Rini Widyastuti; Diyah Saras Wati; Eny Nurhayati
Reaktor Volume 18 No. 1 March 2018
Publisher : Dept. of Chemical Engineering, Diponegoro University

Abstract This research aims to study the reaction kinetics of esterification reaction of glycerol with free fatty acid (FFA) using calcium oxide catalyst to produce mono-diacylglycerol (MDAG) using pseudo-homogeneous approach. The effects of time and temperature on the reaction conversion were investigated simultaneously. The FFA used was from the waste of cocoa production process, while the solid catalyst used was calcium oxide from eggshell ash. The results show that the cocoa based FFA was composed of palmitic acid (49.24%), methyl stearate (1.05%), oleic acid (25.39%), and stearic acid (24.32%). The calcium oxide content in the eggshell ash was 60% w/w. At all temperatures studied (60, 70, and 80oC), as the reaction time increased, the conversion increased sharply in the first 5 minute followed by a gradual raise to an almost constant value after 20 minutes (0.844; 0.845; and 0.854, respectively). Pseudo-homogeneous second order model can describe the reaction kinetics satisfactorily. The reaction constants (k) at 60, 70, and 80oC were 0.00384, 0.003401, and 0.003518 (L/mole.minute), respectively. The effects of temperature on reaction rate obey the Arrhenius’ equation with collision factor (A) is 0.2659 (L/mole.minute) and activation energy (Ea) is 3544 J/mol. Keywords: calcium oxide; free fatty acid; glycerol; pseudo-homogeneous approach

KINETIKA REAKSI HIDROLISIS Megawati Megawati; Wahyudi Budi Sediawan; Hary Sulistyo; Muslikhin Hidayat
Reaktor Volume 12, Nomor 4, Desember 2009
Publisher : Dept. of Chemical Engineering, Diponegoro University

Bio-etanol merupakan salah satu bahan bakar organik yang dapat diproduksi dari pati dan selulosa. Bahan berbasis selulosa dapat ditemukan dalam limbah organik, diantaranya: grajen kayu, ranting kering, daun kering, tongkol jagung, sekam padi dan lain-lain. Langkah-langkah penting pada produksi etanol dari lignoselulosa ialah hidrolisis untuk mengkonversi hemiselulosa dan selulosa menjadi gula, fermentasi gula untuk memproduksi etanol, dan pemurnian etanol. Penelitian ini mempelajari reaksi hidrolisis ranting kering dengan asam encer pada kondisi non-isotermis. Dua ratus gram ranting kering dicampur dengan 1200 cm3 larutan asam sulfat 0,18 N dan dipanaskan di dalam autoklaf. Selama proses hidrolisis ini, suhu akan terus naik (non-isotermis), kemudian setelah mencapai suhu tertentu dijaga tetap (suhu akhir). Hasil hidrolisis pertama diambil pada suhu 413 K dan seterusnya diambil setiap interval 5 menit. Suhu akhir divariasi pada 433 K, 453 K, 473 K dan 493 K. Metode Fehling dipilih untuk menganalisis kandungan gula di dalam sampel. Persamaan kinetika reaksi diperoleh dengan mengolah data dengan pendekatan model shrinking-core dengan ukuran partikel tetap. Nilai tetapan kecepatan reaksi meningkat sedangkan nilai tetapan transfer massa relatif tidak berubah pada berbagai suhu. Tetapan kecepatan reaksi dapat didekati dengan persamaan Arrhenius, dengan frekuensi tumbukan Ar = 0,083 l/(mol.menit) dan energi aktivasi Er = 20.000 J/mol. Untuk menyelidiki langkah mana yang mengontrol laju proses, dibandingkan tetapan kecepatan reaksi dan tetapan transfer massa pada 493 K, diperoleh nilai tetapan transfer massa berkisar 0,06 l/(mol.menit), dan nilai tetapan kecepatan reaksi berkisar 0,00051 l/(mol.menit), sehingga diperoleh bilangan Hatta 0,00933. Karena bilangan Hatta < 0,02 maka dapat disimpulkan bahwa reaksi kimia lebih mengontrol daripada transfer massa.

Kinetics of Enzymatic Hydrolysis of Passion Fruit Peel using Cellulase in Bio-ethanol Production Megawati Megawati; Astrilia Damayanti; Radenrara Putri; Angga Pratama; Tsani Muftidar
Reaktor Volume 20 No.1 March 2020
Publisher : Dept. of Chemical Engineering, Diponegoro University

This research aims to study the hydrolysis of passion fruit peel using cellulase and its evaluation for ethanol production. Passion fruit peel is a fruit processing waste that has not been utilized properly. Passion fruit peel contains holo-cellulose (64% w/w), which can be converted into ethanol through hydrolysis followed by fermentation. Hydrolysis using cellulase is more efficient and its fermentation using yeast to produce ethanol is common. The hydrolysis is carried out at various enzyme ratios (3, 5, 7, and 9% v/v) and at temperature 30 oC, material concentration 5 g/100 mL, pH 4-5, and shaking speed 160 rpm. The kinetics chosen were heterogeneous models; they were the fractal model by Valjamae and Kopelman. Before being hydrolyzed, the essential oil and pectin in passion fruit peel were extracted, because the compositions were quite high; the results were around 16.23 and 11.36% w/w, respectively. The effect of the enzyme ratio to the sugar concentration by hydrolysis is very significant. At 9 h, the glucose concentration reached 45.38, 51.86, 60.50, 66.00 g/L at various enzyme ratios of 3, 5, 7, 9% v/v. During the hydrolysis, the glucose concentration continues to increase and starts to decrease after 9 h. Hydrolyzate solution fermentation obtained from hydrolysis in various enzyme ratios showed consistent results; the higher the enzyme ratio and glucose, and the higher the ethanol will be (5.6, 6.8, 7.6, and 8.9% v/v). The kinetics model by Valjamae is more appropriate to describe the enzymatic hydrolysis mechanism of passion fruit peel than Kopelman. The fractal exponent values obtained from Valjamae and Kopelman models were 0.28 and 0.27. In Valjamae model, the enzyme ratio rises, from 3 to 9% v/v, the rate constant rises from 0.22 to 0.53 1/h. In Kopelman model, the rate constant rises too, from 0.21 to 0.51 1/h.Keywords: bio-ethanol; cellulase; enzymatic hydrolysis; fractal kinetic; passion fruit peel

Co-Authors Alfiansyah Aji Pratama Angga Pratama Anggun Septiamurti Astrilia Damayanti Bahlawan, Zuhriyan Ash Shiddieqy Bayu Triwibowo Catur Rini Widyastuti, Catur Rini Desy Hikmatul Siami Dewi Selvia Fardhyanti Dhoni Hartanto Diyah Saras Wati Eny Nurhayati Eva Amalia Alvionita Hary Sulistyo Izzat Syahmi Kamal Shahrizan Junaidah Jai Luluk Arvi Cahyaning Suwandi Melanie Hartalia Putrie Muslikhin Hidayat Nadya Alfa Cahaya Imani Nur Kholifah Chandra Mulyani Nurul Asyikin Md Zaki Radenrara Putri Ratih Ciptasari Reyhan Dwi Saputra Riana Defi Mahadji Putri Tsani Muftidar Wahyudi Budi Sediawan Widi Astuti Zefanya Pradiza Zulfi Fitriani

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