Risfidian Mohadi
Department of Chemistry, Faculty of Mathematic and Natural Sciences, Sriwijaya University, Jl. Raya Palembang Prabumulih Km32 Ogan Ilir 30662, South Sumatera, Indonesia

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Transesterification of Tropical Edible Oils to Biodiesel Using Catalyst From Scylla serrata Risfidian Mohadi; Hesti A. Harahap; Nurlisa Hidayati; Aldes Lesbani
Sriwijaya Journal of Environment Vol 1, No 2 (2016): Developing Without Destruction
Publisher : Program Pascasarjana Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (342.181 KB) | DOI: 10.22135/sje.2016.1.2.24-27

Abstract

Abstract: Scylla serata shell was decomposed at various temperatures ranging from 700-1100 oC to obtain calcium oxide. Calcium oxide from decomposed Scylla serrata shell was characterized through X-Ray analysis, FTIR spectroscopy, and morphology analysis. Furthermore, decomposed Scylla serrata shell was used as catalyst for transesterification of tropical edible oils to form biodiesel. Biodiesel was characterized through density, viscosity, fatty acid value, and iodine number. The results showed that decomposed Scylla serrata shell at 900 oC could produce calcium oxide similar with standard, which was indicated from X-ray powder diffraction pattern of decomposed shell with JCPDS data. FTIR spectrum showed that main vibration of calcium oxide was observed at 393 cm-1. Morphology analysis using SEM indicated that uniform calcium oxide was obtained after decomposition. The use of decomposed shell as base catalyst for transesterification of tropical edible oils resulted biodiesel with density, viscosity, fatty acid value, and iodine number appropriated with SNI standard.Keywords: transesterification, edible oils, biodiesel, Scylla serrataAbstrak (Indonesian): Scyalla serrata telah didekomposisi pada berbagai suhu dari 700-1100 oC untuk diperoleh kalsium oksida. Kalsium oksida hasil dekomposisi dari cangkang Scylla serrata dikarakterisasi melalui pengukuran sinar X, analisis FTIR, dan analisis morfologi. Lebih lanjut, dekomposisi cangkang Scylla serrata digunakan sebagai katalis transesterifikasi minyak yang dimakan dari daerah tropis menjadi biodisel. Biodiesel dikarakterisasi melalui penentuan densitas, viskositas, nilai asam lemak, dan bilangan iod. Hasil penelitian menunjukkan bahwa dekomposisi cangkang Scylla serrata pada 900 oC dapat menghasilkan kalsium oksida mirip kalsium oksida standar yang diindikasikan dari pola difraksi XRD yang mirip data JCPDS. Spektrum FTIR menunjukkan vibrasi utama kalsium oksida teramati pada bilangan gelombang 393 cm-1. Analisis morfologi menggunakan SEM menunjukkan bahwa bentuk yang lebih seragam diperoleh setelah proses dekomposisi. Penggunaan cangkang hasil dekomposisi sebagai katalis basa untuk transesterifikasi minyak yang dimakan dari daerah tropis menghasilkan biodisel dengan densitas, viskositas, nilai asam lemak, dan bilangan iod yang sesuai dengan standar SNI.Kata kunci: transesterifikasi, minyak yang dimakan dari daerah tropis, biodiesel, Scylla serrata
Preparation Calcium Oxide From Chicken Eggshells Risfidian Mohadi; Kiki Anggraini; Fahma Riyanti; Aldes Lesbani
Sriwijaya Journal of Environment Vol 1, No 2 (2016): Developing Without Destruction
Publisher : Program Pascasarjana Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (407.883 KB) | DOI: 10.22135/sje.2016.1.2.32-35

Abstract

Abstract: The preparation of metal oxide CaO from chicken eggshell has been carried out by decomposition at various temperatures 600, 700, 800, 900, and 1000oC. The metal oxide CaO was characterized using XRD. Furthermore, The optimum temperature for preparation of CaO was determined based on the XRD pattern, then the characterization of CaO was extended using FT-IR spectrophotometer and BET analysis. The results show that the optimum temperature for preparation of CaO from chicken eggshell is 900oC with peak of 2Ө at 32.3o, 37.4o, 53.9o, 64.2o and 67.5o, respectively. The FT-IR spectrums show the unique vibration for Ca-O at 393 cm-1. The BET analysis show that CaO has surface area 68 m2/g with pore volume 1.65 cm3/g and pore size 6.6 nm which can be classified as mesoporous.Keywords: eggshell, base catalyst, CaO, BET, mesoporous Abstrak (Indonesian): Pembuatan oksida logam CaO dari cangkang telur ayam telah dilakukan melalui dekomposisi pada berbagai suhu 600, 700, 800, 900, dan 1000°C. Oksida logam CaO dikarakterisasi dengan XRD. Selanjutnya, Suhu optimum untuk persiapan CaO ditentukan berdasarkan pola XRD, setelah itu karakterisasi CaO dilanjutkan menggunakan FT-IR spektrofotometer dan analisis BET. Hasil penelitian menunjukkan bahwa suhu optimum untuk pembentukan CaO dari cangkang telur ayam adalah 900°C dengan puncak 2Ө muncul di 32.3°, 37.4°, 53.9°, 64.2° dan 67.5°. Spektrum FT-IR menunjukkan vibrasi unik untuk Ca-O di 393 cm-1. Analisis dengan BET menunjukkan bahwa CaO memiliki luas permukaan 68 m2/g dengan volume pori 1,65 cm3/g dan ukuran pori 6,6 nm yang dapat diklasifikasikan sebagai mesopori.Kata kunci: kulit telur, katalis basa, CaO, BET, mesopori
The influence of pyrolysis and matrix modifiers on determination of Cr and Pb in sediment samples by GFAAS Risfidian Mohadi; José A.C. Broekaert
Sriwijaya Journal of Environment Vol 1, No 1 (2016): The First Issue: Green Environment for Future Life
Publisher : Program Pascasarjana Universitas Sriwijaya

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (211.05 KB) | DOI: 10.22135/sje.2016.1.1.14-17

Abstract

Abstract: The Influence of pyrolysis and matrix modifiers on determination of Cr and Pb in sediment samples using graphite furnace atomic absorption spectrometry has been investigated. The sediment samples including three certified reference materials (CRMs) are reported. Analyses were performed using microwave assisted dissolution. The matrix modifiers Mg(NO3)2, Pd+Mg(NO3)2 and NH4H2PO4were shown to be optimazed. The recovery for Cr and Pb in CRMs in the case of sample dissolution was found to be between 81 to 91% for Cr and 94 to 98% for Pb of the certified values, respectively.Keywords: Sediment, Pyrolysis, Matrix modifiers, Cr, PbAbstrak (Indonesia): Pengaruh pirolisis dan matriks pengubah pada penentuan Cr dan Pb dalam sampel sedimen menggunakan tungku grafit spektroskopi serapan atom telah diteliti. Sampel sedimen termasuk tiga bahan referensi bersertifikat (CRMs) dilaporkan dianalisis dengan menggunakan bantuan microwave ekstraktor. Matriks pengubah Mg(NO3)2, Pd+Mg(NO3)2 dan NH4H2PO4 telah digunakan dan menghasilkan nilai temu balik untuk Cr dan Pb dalam CRMs ditemukan antara 81-91% untuk Cr dan 94-98 % untuk Pb dari nilai sertifikat masing-masing.Katakunci: Sedimen, Pirolisis, Matrix modifiers, Cr, Pb