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Iqmal Tahir

Chemistry Department, Faculty of Mathematics and Natural Sciences, Universitas Gadjah Mada, Yogyakarta 55281

Author-ID : 3959186

Chemical Engineering, Chemistry & Bioengineering Chemistry

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STUDY ON THE CONCENTRATION EFFECT OF Nb2O5-ZAA CATALYST TOWARDS TOTAL CONVERSION OF BIODIESEL IN TRANSESTERIFICATION OF WASTED COOKING OIL Astuti Tri Padmaningsih; Wega Trisunaryanti; Iqmal Tahir
Indonesian Journal of Chemistry Vol 6, No 3 (2006)
Publisher : Universitas Gadjah Mada

Study on the concentration effect of Nb2O5-ZAAcatalyst towards total conversion of biodiesel has been conducted. The natural zeolite (ZA) was activated by dipping in NH4Cl solution and was calcined using N2 atmosphere at 500 °C for 5h to produce the ZAA sample. The Nb2O5-ZAA catalyst was made by mixing the activated natural zeolite (ZAA), Nb2O5 3 % (w/w) and oxalic acid 10 % (w/w) solution, until the paste was formed, followed by drying and calcining the catalyst for 3 h at 500 °C under N2 atmosphere. Catalyst characterizations were conducted by measuring acidity with NH3 gas using gravimetric method and porosimetric analysis using N2 gas adsorption based on the BET equation by surface area analyzer instrument. The Nb2O5-ZAA catalyst was then used as an acid catalyst in free fatty acid esterification reaction of wasted cooking oil in methanol medium with variation of catalyst concentration: 1.25%; 2.5%; 3.75% and 5% towards the weight of oil+methanol. The reaction was continued by transesterification of triglyceride in the used cooking oil using NaOH catalyst in methanol medium. For comparison, the esterification reaction using H2SO4 catalyst 1.25% towards the weight of oil+methanol has been conducted as well. Methyl ester (biodiesel) product was analyzed using Gas Chromatography (GC) and Gas Chromatography-Mass Spectrometry (GC-MS). The characters of biodiesel were analyzed using American Society for Testing and Materials (ASTM) method. The results showed that modification of ZAA by impregning Nb2O5 3% (w/w) increased the total catalyst acidity from 5.00 mmol/g to 5.65 mmol/g. The Nb2O5-ZAA catalyst has specific surface area of 60.61 m2/g, total pore volume of 37.62x10-3 cc/g and average pore radius of 12.41 Å. The Nb2O5-ZAAcatalyst with concentration of 1.25%-5% produced higher total conversion of biodiesel than that of H2SO4 catalyst 1.25%. The Nb2O5-ZAA catalyst with concentration of 3.75% produced the highest total conversion of biodiesel, i.e. 76.76 %. Based on the ASTM data analysis, the product has a qualification as diesel fuel.

PHOTODEGRADATION OF ALIZARIN S DYE USING TiO2-ZEOLITE AND UV RADIATION Karna Wijaya; Eko Sugiharto; Is Fatimah; Iqmal Tahir; Rudatiningsih Rudatiningsih
Indonesian Journal of Chemistry Vol 6, No 1 (2006)
Publisher : Universitas Gadjah Mada

An investigation of Alizarin S photodegradation using TiO2-zeolite and UV radiation was performed. TiO2-zeolite was prepared by dispersing oligocations of titanium into suspension of zeolite. The suspension was stirred and then filtered to separate the solid phase from the filtrate. the solid phase was calcined by microwave oven at 800 Watt for 5 minutes to convert the oligocations into its oxide forms. The calcined product and unmodified zeolite were characterized using x-ray diffractometry, FT-IR spectrophotometry, X-ray fluorescence and gas sorption analysis methods to determine their physicochemical properties. Photocatalytic activity of TiO2-zeolite was tested on Alizarin S solution using following method: 50 mg of zeolite was dispersed into 25 mL of 10-4 M Alizarin S. The dispersion was irradiated using 365 nm UV light at room temperature on various irradiation times, i.e. 10, 20, 30, 40 and 60 minutes. At certain irradiation time, the dispersion was filtered and the filtrate was then analyzed its concentration using UV-Vis spectrophotometry method. Characterization results exhibited that the formation of TiO2 on internal as well as external surfaces of zeolite could not be detected with x-ray diffractometry and FT-IR spectrophotometry, however determination of titanium using x-ray fluorescence analysis on the calcined product showed that the concentration of titanium was much higher than zeolite (0.22% on zeolite and 12.08% on TiO2-zeolite). Gas sorption analysis result indicated that the the calcination resulted in the increase of specific surface area (16,31 m2/g on zeolite and 100.96 m2/g on TiO2-zeolite) as well as total pore volume of calcined product (13.34 mL/Å/g on zeolite and 57.54 mL/Å/g on TiO2-zeolite). The result of photocatalytic activitiy study showed that ca 99 % of Alizarin S was degraded by TiO2-zeolite after UV irradiation for 60 min.

TITANIUM OXIDE DISPERSED ON NATURAL ZEOLITE (TiO2/ZEOLITE) AND ITS APPLICATION FOR CONGO RED PHOTODEGRADATION Is Fatimah; Eko Sugiharto; Karna Wijaya; Iqmal Tahir; Kamalia Kamalia
Indonesian Journal of Chemistry Vol 6, No 1 (2006)
Publisher : Universitas Gadjah Mada

The utilization of TiO2 dispersed on natural zeolite (TiO2/Zeolite) for degradation of Congo Red photocatlytically has been performed. The TiO2/Zeolite was prepared by mechanically mixing of 100 g of natural zeolite, which it has been heated at 400oC, with TiO2 powder, the final weight ratio of the mixture was 5% (w/w). The mixture was then calcined at 400oC for 6 hours. The calcined product was characterized using x-ray diffractometry, x-ray fluorescence analysis and gas sorption analysis methods to determine its physicochemical properties changes caused by mixing and calcination. Investigation of Congo Red photodegradation using TiO2/Zeolite was carried out by mixing 25 mL 10-4 M solution of Congo Red with 25 mg of TiO2/Zeolite and irradiating the suspention with UV-light of 350 nm for 10, 20, 30, 40, 50 and 60 minutes, respectively. The characterization results showed that dispertion of TiO2 on zeolite resulted in the increasing of titanium concentration on TiO2/Zeolite. The concentration of Ti on natural zeolite was found to be 0.15%(w/w), meanwhile on TiO2/Zeolite was 2.29% (w/w). From X-ray diffractometry analysis result no information was found that TiO2 was dipersed on natural zeolite. It was caused by overlapping of the reflections of zeolite with reflections of TiO2. On the otherhand, the gas sorption analysis result exhibited that the dispersion of TiO2 on zeolite resulted in the decreasing of total pore volume as well as specific surface area of the natural zeolite. The specific surface areas of natural zeolite and TiO2/Zeolite were 21.98 and 16.74 m2/g, respectively, meanwhile the total pore volumes of natural zeolite and TiO2/Zeolite were 20.10x10-3 and 13.47x10-3 mL/g. The simple kinetic of photodegradation of Congo Red exhibited that the rate of degradation followed a first order kinetic and the reaction rate constant was 0.0017 minute-1.

SYNTHESIS OF ANTIMALARIAL 3-(2-HYDROXYETHYL)-2-METHYL-1,10-PHENANTHROLINE-4-OL FROM 8-AMINOQUINOLINE Ruslin Hadanu; Chairil Anwar; Jumina Jumina; Iqmal Tahir; Mustofa Mustofa
Indonesian Journal of Chemistry Vol 4, No 2 (2004)
Publisher : Universitas Gadjah Mada

It has been conducted the synthesis of 3-(2-hydroxyethyl)-2-methyl-1,10-phenanthroline-4-ol was carried out from 8-aminoquinoline which are expected to posses antimalarial activity. The experiment perfomed consisted of two steps i.e (1) reaction of 8-aminoquinoline with 2-acetyl-butyrolactone and (2) cyclization of the resulted 3-[1-(quinolin-8-ylamino)-ethylidene]-4,5-dihydro-furan-2-one. The reaction of 8-aminoquinoline with 2-acetyl-butyrolactone was performed in toluene at reflux for 6 hours in the presence of p-toluensulfonic acid as catalyst. This reaction gave 3-[1-(quinolin-8-ilamino)-etiliden]-4,5-dihidro-furan-2-on in 60.6% yield. The cyclization of 3-[1-(quinoline-8-ylamino)-ethyliden]-4,5-dihydro-furan-2-one was conducted in cloroform at reflux for 4 hours in the presence of H2SO4 as catalyst and also tween 80 as transfer phase catalyst to give 3-(2-hydroxy-ethyl)-2-methyl-1,10-phenanthroline-4-ol in 76.2% yield. Identification of the products were carried out by means of infra red (IR) spectroscopy, proton nuclear magnetic resonance (1H-NMR) spectroscopy, and mass spectroscopy (MS).

Co-Authors Astuti Tri Padmaningsih Chairil Anwar Eko Sugiharto Is Fatimah Jumina Jumina Kamalia Kamalia Karna Wijaya Mustofa Mustofa Rudatiningsih Rudatiningsih Ruslin Hadanu Wega Trisunaryanti

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