Aromatic hydrocarbons adsorbed emission

Technologies have been developed to reduce the hydrocarbon emissions during cold start. One of the technologies, the hydrocarbon adsorber [1-3] has been most attractive to automotive makers because it has the advantage in view of cost and performance. Hydrocarbons of the cold start depend on the condition of a vehicle, fuel and driver. About 100 hydrocarbon species are present in the exhaust of the cold start. They consist of about 10% methane, about 30% alkenes such as ethylene or propene, about 30% alkanes such as pentane or hexane, about 20% aromatics such as toluene or xylene, and about 10% other species. Therefore, a hydrocarbon adsorber has to show a good selectivity for the hydrocarbons. In order to remove the adsorbed hydrocarbons effectively, the hydrocarbon adsorber needs to have an additional function, hydrocarbon conversion. 

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