| 摘要 |
Molecular sieves and the use of such materials as hydrocarbon traps, particularly for reducing the emissions associated with the combustion of hydrocarbon fuels are described. Specifically, the use of molecular sieves such as zeolites as adsorbents for hydrocarbon gases, especially exhaust gases such as are formed during the combustion of hydrocarbons, and more particularly to the adsorption of hydrocarbon gases formed during the cold start operation of an internal combustion engine is described. In one embodiment, a method of treating exhaust gas that comprises a hydrocarbon combustion product is provided, the method comprising contacting the exhaust gas with a CON topology molecular sieve for a time period effective to facilitate adsorption of the hydrocarbon combustion product by the molecular sieve; passing a purge gas through the molecular sieve to remove adsorbed hydrocarbon combustion product; and contacting the purge gas containing the removed hydrocarbon combustion product with a hydrocarbon conversion catalyst. A system is also provided for treating exhaust gases formed from the combustion of a hydrocarbon in which the system includes an exhaust gas adsorption unit containing an adsorbent CON topology molecular sieve; a catalytic converter unit containing a hydrocarbon conversion catalyst; means for supplying an exhaust gas comprising a hydrocarbon combustion product to the adsorption unit so that the hydrocarbon combustion product is at least partly adsorbed by the molecular sieve; means for transferring the hydrocarbon combustion product from the adsorption unit to the catalytic converter unit wherein the hydrocarbon combustion product is converted to an exhaust emission gas; and means for exhausting the exhaust emission gas from the catalytic converter unit.
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