(304b) Hydrocarbon and Water Adsorption-Interactions On Zeolite HC Traps

Hydrocarbon and Water Adsorption-Interactions on Zeolite HC Traps.

Manish Sharma, Ford Motor Company.

Acidic Zeolites have found use as Hydrocarbon (HC) Traps in the automotive world for reducing the HC emissions during the cold start of a vehicle engine. The feedgas to the zeolite trap on vehicle contains both HCs and water, present in the vehicle exhaust. The various HC species and water compete for adsorption on the zeolites. This talk will present the results of a laboratory and modeling study on the interactions between adsorbing water and HC species on the zeolite sites. Lab experiments conducted on zeolites to study the competitive adsorption of various HCs and water will be presented. Experiments have been conducted where different HCs and water were sequentially adsorbed on the zeolite, and TPD was conducted. For modeling, Langmuir isotherm was assumed to represent the adsorption phenomena on the zeolite sites. A brief introduction of the mathematical model will be followed by simulation results showing the competitive adsorption between various HC species and water. Lab data has been used to calibrate and validate the individual adsorption parameters for the adsorbed species. Interesting exothermic effects of water adsorption on acidic zeolites will also be presented.