Characterization and Modification of Natural Zeolite and Its Cracking Properties on Petroleum Fraction = Karakterisasi dan Modifikasi Zeolit Alam dan Sifat Perengkahannya terhadap Fraksi Minyak Bumi.

Abstract

Preparation of natural zeolite catalyst consist of dealumination using acid (HF 1% (v/v), HCI 1 M), steaming at calcination temperature and both treatments ware carried out. The modification of the zeolite catalyst was done by loading a small amount of chromium (3% b/b) on the zeolite by ion exchange method. Ion exchange was processed by immersing the zeolite in 0,115 M chromium nitrate solution, followed by oxydation with oxygen gas and reduction by hydrogen gas. The characterization of the zeolite catalyst by mean of Si/AI ratio, acidity, metal contents (Na, K, Ca, Fe and Cr) and surface area including pore size distribution were determined by gravimetric method, ammonia adsorption, Atomic Adsorption Spectroscopy (AAS) and nitrogen gas sorption analyzer (NOVA-1000), respectivelly. The result of characterization showed that dealumination process increased the Si/AI ratio, acidity and decreased the metal content. The result of cracking process showed that modification of the natural zeolite catalyst enhanched the catalysis property, it showed relatively high cracking activity of petroleum fraction and low kokass formation. Key words: Chromium-natural zeolite, Characterization, Dealumination, Steamin