Sri Sudiono
Chemistry Department, Faculty of Mathematics and Natural Sciences Gadjah Mada University, Yogyakarta

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PREPARATION, CHARACTERIZATIONS AND MODIFICATION OF Ni-Pd/NATURAL ZEOLITE CATALYSTS Wega Trisunaryanti; Endang Triwahyuni; Sri Sudiono
Indonesian Journal of Chemistry Vol 5, No 1 (2005)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (175.92 KB) | DOI: 10.22146/ijc.21838

Abstract

Preparation, and modification of Ni-Pd/natural zeolite as well as their characterizations had been carried out. The aim of this research for the fututure is to prepare the best characters catalyst for the conversion of waste plastics fraction to gasoline fraction (C5-C12 hydrocarbons). The preparation of catalysts was performed by reacting a natural zeolite with the precursor of Ni(NO3)2. 9H2O and PdCl2 in an ammonia solution (25%). The modifications were performed by varying the rasio of Ni/Pd loaded to the zeolite, whereas the Pd was previously loaded and total metal content was 1 wt.% based on the zeolite. The characterization of catalysts included determination of acidity gravimetrically by adsorption of ammonia or pyridine vapour  base method, metal content by Atomic Adsorption Spectrophotometer (AAS) and X-ray Fluoresence (XRF) and crystallinity by X-ray Diffraction (XRD). The treatment of catalysts using Etilene Diamine Tetra Acetic acid  (EDTA) was performed to study the metal distribution on the outer or inner surface of the zeolite. The characterization results showed that the loading of metals to the zeolite increased its acidity and decreased its spesific surface area, however, did not defect its crystallnity.  The metals loaded on the zeolite were distributed inside the pore and at outer surface of the zeolite. For all catalyst samples, the acidities determined using ammonia were higher than those of pyridine, and the acidities determined before the EDTA treatment was lower than those after the treatment.  Metal contents of the zeolite before the EDTA treatment were higher than those after the treatment. The EDTA treatment enhanced the crystallinity of the sampel. The relationship between the metal rasio towards the acidity of the catalyst samples were in variation. Catalyst samples produced in this research have good characters, thus promisingly can be used for conversion process of waste plastics to gasoline fraction.
THERMAL EFFECT OF COCONUT CREAMS ABILITY TO ADSORB CALCIUM(II) Fatmawati Tahir; Ani Setyopratiwi; Sri Sudiono
Indonesian Journal of Chemistry Vol 2, No 2 (2002)
Publisher : Universitas Gadjah Mada

Show Abstract | Download Original | Original Source | Check in Google Scholar | Full PDF (42.774 KB) | DOI: 10.22146/ijc.21924

Abstract

Study of thermal effect of coconut cream's ability to adsorb Ca (II) has been done at various temperatures of 49 oC,  59 oC and 80 oC. The adsorption study was performed to check capacity, energy and rate of adsorption by varying the number of initial concentration of CaCl2 bounded on coconut protein. This research was also done to determine number of Ca (II) in the coconut protein using the salt addition and elicits reaction methods. The result showed that adsorption ability tends to increased with the increase of temperature). Coconut cream heated at 59 oC adsorb Ca(II) with the highest adsorption capacity of 3.98 mg/g and K = 3.48x104  mol-1. The salt addition method on the coconut cream gives more Ca (II) than elicit reaction method. The first method gives 0.01137 mol/L and the second was 0.02845 mol/L. Based on the energy of adsorption, cream without heating had 20.59 kJ/mol as a physical adsorption and heating effect at temperatures 49 oC, 59 oC and 80 oC had 24.95; 28.87 and 24.87 kJ/mol respectively as a chemical adsoprtion with the rate of adsorptions of 0,0054;  0,0510 dan  0,3. 10-4 minute-1, respectively.