Cold-Start Emissions Control in Hybrid Vehicles Equipped with a Passive Adsorber for Hydrocarbons and NOx

Z. Gao, C.S. Daw, M.-Y. Kim, J.-S. Choi, J.E. Parks II, and D.E. Smith

Oak Ridge National Laboratory

Supported by the Laboratory Directed Research and Development (LDRD) Seed Money program at Oak

Ridge National Laboratory

2012 DOE-DEER Conference Oct. 18, 2012

Poster – P13

2 Managed by UT-Battelle for the U.S. Department of Energy

Our studies reveal the potential for using chemisorbing materials to temporally trap HC and NOx emissions during cold-start periods in HEVs and PHEVs over transient driving cycles.

• HC and NOx tailpipe emissions can be reduced several fold with the appropriate combination of sorbent properties

• Impact of the passive trapping depends on sorbent properties and engine exhaust temperature swings

• Larger benefits may be possible for PHEVs

HC: 0.052 g/kmNOx: 0.077 g/km

2.2-L TWC

HC: 0.052 g/kmNOx: 0.077 g/km

2.2-L TWC

HC: 0.052 g/kmNOx: 0.077 g/km

2.2-L TWC

0

500

1000

1500

2000

2500

0 10 20 30 40 50 60 70Time (min)

C 3H 6

(ppm

)

0

100

200

300

400

500

Tem

pera

ture

(o C)

Temperature

C3H6 Inlet

C3H6 outlet(test)

C3H6 outlet(model)

0

100

200

300

400

500

0 10 20 30 40 50 60 70Time (min)

NO

x (p

pm)

0

100

200

300

400

500

Tem

pera

ture

(o C)

Temperature

NOx Inlet

NOx outlet (test)

NOx outlet (model)

0.66-L Adsorber

1.1-L TWC

HC: 0.016 g/kmNOx: 0.056 g/km

1.1-L TWC

0.66-L Adsorber

1.1-L TWC

HC: 0.016 g/kmNOx: 0.056 g/km

1.1-L TWC

HC and NOx nreakthrough profiles for the fixed-bed sorber containing a mixing sorbent Poster – P13