Proceedings of International Conference on Mechanical & Manufacturing Engineering (ICME2008), 21– 23 May 2008, Johor Bahru, Malaysia. © Faculty of Mechanical & Manufacturing Engineering, Universiti Tun Hussein Onn Malaysia (UTHM), Malaysia. ISBN: 97–98 –2963–59–2 1 Effects of Porous Ceramic/Zeolite to the Exhaust System of Gasoline Engine Shahrin Hisham Amirnordin * , Hamimah Abd. Rahman, Khairul Nor Othman, Mohd Fahrul Hassan, Ahmad Jais Alimin Faculty of Mechanical and Manufacturing Engineering Tun Hussein Onn University of Malaysia (UTHM) Parit Raja, Batu Pahat, 86400 Johor Malaysia *shahrin@ uthm.edu.my Abstract: Porous ceramics have received wide recognition in industrial applications as a filter to trap particulates, ions and gases. Nevertheless, considerable attention has been given to improve its treatment capability in the exhaust emission control technology. This research focuses on the application of porous ceramic/zeolite filter on the exhaust system of 1300 cc gasoline engine. Emission analysis on four compositions of filters has been investigated and the comparison is made to the standard ceramic catalytic converter available in the market. A filter with the composition of 90 vol.% alumina, 10 vol.% zeolite with additional 50 vol.% yeast exhibits significant results in reducing both hydrocarbon (HC) and carbon monoxide (CO). Other filters also work effectively towards HC treatment but the reduction of CO only obviously improves above 1800 rpm. Further experiments indicate the use of filter independently has outperformed other configurations by presenting the lowest normalized emission for CO and HC. Therefore, porous ceramic/zeolite filter has shown its outstanding potential to improve the emission performance of gasoline engine. Keywords: porous ceramic, zeolite. 1. Introduction Porous ceramics are brittle materials with closed, fully open, or partially interconnected porosity. It’s application is widely accepted in many fields including catalysis, filtration, impact absorbing structures, high specific strength materials, biomechanical implants and high efficiency combustion burners [1,2]. Zeolites are the aluminosilicate members of the family of microporous solids known as molecular sieves which refers to the ability to selectively absorb molecules based primarily on a size exclusion process. Widely used as ion-exchange beds in water purification, molecule separation, catalysts and known for its potential in separation of specific gases. More than 150 zeolites have been synthesized and 48 naturally occurring zeolites are known [3]. Clinoptilolite is one of the naturally occurring zeolite used in this study. In the exhaust treatment of automobiles, zeolites have received attention