Method and apparatus to improve catalyzed hydrocarbon trap efficiency

摘要

The present invention provides a method for removing hydrocarbons from an exhaust gas of an internal combustion engine. The method of the present invention comprises contacting the exhaust gas with a water-removing composition and then contacting the exhaust gas at a position downstream from the water-removing composition with a hydrocarbon-removing material to remove at least some of the hydrocarbons from the exhaust gas. The hydrocarbon-removing material use in the present invention has a sufficiently low Si to Al atom ratio that less than 50% of the low molecular hydrocarbons desorb from the hydrocarbon-removing composition at a temperature of 250° C.