Engine exhaust system with reduced hydrocarbon emissions

Abstract From the Canadian patent

of the Invention, An engine exhaust system is disclosed which in operation is capable of substantially reducing the quantities of hydrocarbons emitted to the atmosphere during engine start-up. The system utilizes molecular sieve means, such as a high-silica zeolite, which function to adsorb hydrocarbons emitted during engine start-up before, the catalytic converter has attained its effective operating temperature. The system is designed so that once the catalytic converter has attained an effective operating temperature, the hydrocarbons can be desorbed from the molecular sieve means and conveyed to the converter for conversion to non-toxic by-products.