Abstract
We present results from a computational study of the potential for using low-cost sorbent materials to trap the emissions of hydrocarbons and nitrogen oxides temporally during cold-start periods in hybrid electric vehicles and plug-in hybrid electric vehicles operating over transient driving cycles. The hydrocarbon adsorption behavior of a candidate sorbent composed of Ag-beta-zeolite was characterized in a laboratory flow reactor to estimate the kinetic parameters for a one-dimensional transient adsorber device model. This model was then implemented in the Powertrain Systems Analysis Toolkit to simulate a passive hydrocarbon adsorber device on a hybrid vehicle. The results indicate that such an adsorber can substantially reduce the hydrocarbon emissions by temporarily storing them until the three-way catalyst is sufficiently warm to remove them from the exhaust. A similar adsorber device model was simulated for nitrogen oxide control, using an initial set of conjectured kinetic parameters for transition metal oxides based on limited information in the literature. These latter simulations revealed the need to pursue additional experimental studies to characterize fully this class of sorbents. Such studies are especially relevant in the present context of rapidly evolving vehicle technology, because emission controls of this type do not involve any penalty in fuel consumption or require any change in engine operation.
| Original language | English |
|---|---|
| Pages (from-to) | 1396-1407 |
| Number of pages | 12 |
| Journal | Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering |
| Volume | 226 |
| Issue number | 10 |
| DOIs | |
| State | Published - Oct 2012 |
Funding
Forrest Jehlik and Eric Rask of Argonne National Laboratory provided helpful information regarding some of our simulation parameters for the Toyota Prius. We are also grateful to our colleagues in the Fuels, Engines, and Emissions Research Center at Oak Ridge National Laboratory who have contributed helpful suggestions and insights. The contribution of Mi-Young Kim was supported in part by an appointment to the Oak Ridge National Laboratory Postdoctoral Research Associates Program administered jointly by the Oak Ridge Institute for Science and Education and the Oak Ridge National Laboratory. We also appreciate the contribution of time and helpful comments from Journal of Automobile Engineering reviewers. This work was supported by the Laboratory Directed Research and Development Seed Money program (grant no. S10-055) at Oak Ridge National Laboratory and was sponsored by a contractor of the US Government under contract DE-AC05-00OR22725 with the US Department of Energy.
Keywords
- Cold start
- emissions control
- hybrid electric vehicle
- passive adsorber