DESIGN, FABRICATION AND TESTING OF A 4-WAY CATALYTIC CONVERTER FOR REDUCING EXHAUST EMISSION POLLUTION IN A DIESEL AUTOMOBILE ENGINE

摘要

Demand for automobiles is increasing by the day all over the world. Diesel oil being cheaper than gasoline, diesel vehicles are being used for personal purposes than the commercial applications. It is projected that by 2030, 1300 million automobiles will be plying on roads. Due to incomplete combustion of fuel oil pollutants like CO, HC, and NO_x are released into atmosphere causing negative impact on air quality, environment and human health. Researchers all over the world concentrated on how to reduce the pollutants. Euro norms specify the allowable percentages of CO, HC and NO_x in the exhaust gases. Euro norms being implemented in the developed countries have given stringent values, which has led to the development of catalytic converter which is added equipment in automobile. Hitherto in the catalytic converters supplied in modern cars, Platinum and Rhodium metals are used for coating monoliths. These metals are rare, and hence expensive. From Euro 4 onwards NO_x values are reduced drastically. Hence, NO_x abatement has become a major issue. In the research carried out by authors, alternative coating materials like CeO_2, ZrO_2 which help NO_x abatement and oxygen storage are used over clay marbles. These were designed, fabricated and tested on automobiles. The results are encouraging showing marked fall of pollutants in exhaust gases.