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Studi Penggunaan Katalis Tembaga Molybdenum Oksida Berpenyangga Silica (CuMoO3/SiO2) Untuk Oksidasi Metana Menjadi Methanol Dan Formaldehida H. Husin; Marwan Marwan
Reaktor Volume 08 No.1 Juni 2004
Publisher : Dept. of Chemical Engineering, Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (4519.252 KB) | DOI: 10.14710/reaktor.8.1.37-42

Abstract

Studi penggunaan katalis tembaga molybdenum oksida berpenyangga silica (CuMoO3/SiO2) untuk oksidasi parsial metana menjadi methanol dan formaldehida telah dilakukan. Preparasi katalis dilakukan dengan metode impregnasi. Hasil identifikasi dengan XRD menunjukkan bahwa komponen katalis terdiri dari senyawa MoO3, Cu2Odan SiO2. Uji kinerja katalis dilangsungkan dalam reaktor pipa lurus berunggun tetap, beroperasi pada temperature 400, 450 dan 500 0C dan tekanan 1 atm. Produk reaksi dianalisis menggunakan gas kromatografi buatan Shimadzu dengan kolom mole sieve 5A dan porapak Q. Konversi metana tertinggi diperoleh 34,1% menggunakan katalis dengan rasio  Cu: Mo 1: 3, temperatur reaksi 400 0C. Perolehan methanol tertinggi 3,4 % dan perolehan formaldehida tertinggi 7,3%.Kata kunci : oksidasi parsial metana, katalis (CuMoO3/SiO2), impregnasi, methanol, formaldehida
Production of Triacetin by Microwave Assisted Esterification of Glycerol Using Activated Natural Zeolite Marwan Marwan; Eti Indarti; Darmadi Darmadi; Wahyu Rinaldi; Dzikri Hamzah; Taufik Rinaldi
Bulletin of Chemical Reaction Engineering & Catalysis 2019: BCREC Volume 14 Issue 3 Year 2019 (December 2019)
Publisher : Department of Chemical Engineering - Diponegoro University

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (2452.193 KB) | DOI: 10.9767/bcrec.14.3.4250.672-677

Abstract

Triacetin, an alternative biodiesel additive, was prepared by esterification of glycerol with acetic acid in the presence of chemically activated natural zeolite. The esterification was carried out in a small reaction flask under microwave irradiation. The catalyst was characterized for its morphology by SEM and its chemical composition by X-ray Diffraction (XRD). The Scanning Electron Microscopy (SEM) micrograph indicates improved surface area of the zeolite, while the XRD analysis shows an increase in Si/Al ratio from natural zeolite to 6.042 and its crystallinity value of 12.23%. The Fourier Transform Infra Red (FTIR) analysis obtained showed that microwave-heated samples have an esters group spectrum of triacetin at 1702 cm-1. The conversion value of glycerol was more than 95% at molar ratio of the reactants 1:9 and catalyst loading of 3%. The selectivities for monoacetin, diacetin and triacetin were 80.1%, 15.4%, and 4.5% at 60 minutes, and 43.0%, 48.6%, and 8.3% at 90 minutes. It shows that the conversion took place in consecutive steps and the use of microwave allows the reaction proceeding at milder condition. 
Characterization of Titania (TiO2) Catalysts Prepared by Sol-Gel Method Marwan Marwan; Naoto Azuma; Akinori Maezawa; Shigeo Uchida
ASEAN Journal of Chemical Engineering Vol 3, No 1 (2003)
Publisher : Department of Chemical Engineering, Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (456.757 KB) | DOI: 10.22146/ajche.50858

Abstract

Various TiO2 catalysts in powder form were prepared ny sol-gel method and then characterized for X-ray diffraction and BET surface area. VAriation in composistion of reactants, choice of hydrolysing catalyst, calcination temperature, and method of drying were among preparative variable evaluated. Addition Pt, Fe2O3, CuO and SiO2 on the catalysts was also carried out during the initial stage of sol formation. XRD analysis suggest that all catalysts calcined at 450'C were compeltelu in anatase phase. BET surface area of the catalysts revealed that the catalysts prepared using HNO3 as hydrolysing catalyst, have a surface area larger than the commercial Degussa P25 TiO2 catalyst, with the highest area of 126m2/g. The addition of metals resulted in a lower surface area, while silica provided a considerable incdease in surface area, at 257 m2/g. Analyses of isotherms plot and BJH desorption plots suggest that particle pores were dominated by a bottle-like share. However, the photocalatylstic activity of these catalysts in te degradation of sufactant failed to meet the perfomance rating of Degussa P23 TiO2 catalyst, probably due to less access of surfactant into interbal surface of the prepared catalysts. Degradation of the surfactant usidng different particle sizes suggests that the external surface of TiO2 catalysts was important under liquid phase degradation.
Kinetics of Phenol Degradation in Aqueous Solution Oxidized under Low Frequency Ultrasonic Irradiation Marwan Marwan
Jurnal Rekayasa Kimia & Lingkungan Vol 10, No 1 (2014): Jurnal Rekayasa Kimia & Lingkungan
Publisher : Chemical Engineering Department, Syiah Kuala University, Banda Aceh, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (323.801 KB) | DOI: 10.23955/rkl.v10i1.2170

Abstract

Phenol is categorized as a refractory pollutant and its presence in water stream is strictly limited according to the government regulation. The present study investigated the degra-dation of phenol in aqueous solution by the effect of ultrasound. The process took place in a 500 ml glass reactor equipped with magnetic stirring and irradiated by low frequency (28 kHz) ultrasound from a horn type probe. Ultrasonic irradiation was found to enhance oxidation rates at ambient conditions, compared to other approaches. Optimum conditions were observed at a stirring speed of 400 rpm and temperature of 30 C in acidic solution. It was revealed that the phenol degradation was the first order kinetics with respect to phenol. A low value of the activation energy 6.04 kcal/mol suggested that diffusional steps were rate determining during the phenol decomposition. It also confirmed that phenol was mostly degraded in the film region and less occurred in the bulk solution.
Water Quality Assessment in the Tsunami Areas of Banda Aceh Suhendrayatna Suhendrayatna; Marwan Marwan; Edi Munawar; Muhammad Zaki
Jurnal Rekayasa Kimia & Lingkungan Vol 7, No 1 (2009): Jurnal Rekayasa Kimia & Lingkungan
Publisher : Chemical Engineering Department, Syiah Kuala University, Banda Aceh, Indonesia

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (295.274 KB)

Abstract

Water quality assessment in the tsunami-affected areas conducted in Meuraxa and Kutaradja sub-districts in the area of Banda Aceh City. Water samples were collected in October 2006 from dug wells of tsunami-affected areas. These were characterized for various physical and chemical parameters. Water quality in the selected areas has shown that the surface water was contaminated due to the tsunami. Total Dissolved Solid, Total Suspended Solid, Acidity, and salinity were high in the affected areas indicating saline water intrusion into surface water tables. Dug wells in the highly affected locations showed higher values of heavy metal ions like Mn, Pb, Cu, Fe, Zn, and Cu compared to the reference points. No ion Hg was found in all samples. Keywords: Banda Aceh, heavy metals, tsunami, water quality
Production of Triacetin by Microwave Assisted Esterification of Glycerol Using Activated Natural Zeolite Marwan Marwan; Eti Indarti; Darmadi Darmadi; Wahyu Rinaldi; Dzikri Hamzah; Taufik Rinaldi
Bulletin of Chemical Reaction Engineering & Catalysis 2019: BCREC Volume 14 Issue 3 Year 2019 (December 2019)
Publisher : Masyarakat Katalis Indonesia - Indonesian Catalyst Society (MKICS)

Show Abstract | Download Original | Original Source | Check in Google Scholar | DOI: 10.9767/bcrec.14.3.4250.672-677

Abstract

Triacetin, an alternative biodiesel additive, was prepared by esterification of glycerol with acetic acid in the presence of chemically activated natural zeolite. The esterification was carried out in a small reaction flask under microwave irradiation. The catalyst was characterized for its morphology by SEM and its chemical composition by X-ray Diffraction (XRD). The Scanning Electron Microscopy (SEM) micrograph indicates improved surface area of the zeolite, while the XRD analysis shows an increase in Si/Al ratio from natural zeolite to 6.042 and its crystallinity value of 12.23%. The Fourier Transform Infra Red (FTIR) analysis obtained showed that microwave-heated samples have an esters group spectrum of triacetin at 1702 cm-1. The conversion value of glycerol was more than 95% at molar ratio of the reactants 1:9 and catalyst loading of 3%. The selectivities for monoacetin, diacetin and triacetin were 80.1%, 15.4%, and 4.5% at 60 minutes, and 43.0%, 48.6%, and 8.3% at 90 minutes. It shows that the conversion took place in consecutive steps and the use of microwave allows the reaction proceeding at milder condition.