This content is not included in your SAE MOBILUS subscription, or you are not logged in.
An Assessment of the Plasma Assisted Catalytic Reactor (PACR) Approach to Lean NOx Abatement: The Relative Reducibility of NO and NO2 using #2 Diesel fuel as the Reductant
ISSN: 0148-7191, e-ISSN: 2688-3627
Published October 16, 2000 by SAE International in United States
Annotation ability available
The plasma assisted catalytic reactor (PACR) approach to lean NOx abatement is a two step process. The non-thermal plasma oxidizes the engine out NO to NO2, which is then reduced to N2 over a catalyst using a hydrocarbon reductant. Whereas it was once believed that the plasma itself directly reduces NOx to N2, it has been shown that the plasma's principle function is to oxidize NO to NO2. This is accomplished without oxidizing SO2 to SO3, resulting in lower sulfate particulate when compared to standard lean NOx catalysis using platinum or reducible oxide catalysts. We have performed reactor studies comparing the relative reducibility of NO2 and NO in a synthetic diesel exhaust using diesel fuel as the hydrocarbon reductant, with attention to time-on stream behavior and determination of NOx reversibly adsorbed on the catalyst. We find that at 200°C, 50% of the NO2 disappearance over Na-ZSM5 is attributable to reversible adsorption on the catalyst. For a 200 M2/g γ-alumina catalyst, 15% of the NOx disappearance is due to adsorption, with 85% of the NOx disappearance attributable to NO2 conversion to N2. However, the γ-alumina catalyst has limited utility. With increasing time on stream, diesel fuel adsorption on the γ-alumina decreases the catalyst activity, and at temperatures above 220°C, NOx reduction activity over γ-alumina for NO and NO2 feeds are identical. In contrast, H-ZSM5 shows higher reduction activity for NO2 than for NO from 150°C to 500°C. Maximum conversions for monolith supported H-ZSM5 at 14,000/hr space velocity are only 25% at 200°C, and decrease with increasing temperature. We conclude that in the absence of plasma generated hydrocarbon species that increase the reduction efficiency of diesel fuel, these catalysts alone cannot be used in the catalyst - reductant sub-system of a plasma assisted catalytic reactor for lean-NOx abatement.
CitationLampert, J., "An Assessment of the Plasma Assisted Catalytic Reactor (PACR) Approach to Lean NOx Abatement: The Relative Reducibility of NO and NO2 using #2 Diesel fuel as the Reductant," SAE Technical Paper 2000-01-2962, 2000, https://doi.org/10.4271/2000-01-2962.
- Penetrante B.M. Brusasco R.M. Merritt B.T. Pitz W.J. Vogtlin G. E. Kung M.C. Kung H.H. Wan C.Z. Voss K.E. “Plasma-Assisted Catalytic Reduction of NOx” SAE paper 982508 1998
- Balmer M. L. Tonkyn R. Kim A. Yoon S. Jimenez D. Orlando T. Barlow S.E. Hoard J. “Diesel NOx Reduction on Surfaces in Plasma” SAE paper 982511 1998
- Balmer M. L. Tonkyn R. Yoon S. Kolwate A. Barlow S.E. Maupin G. Hoard J. “NOx Destruction Behavior of Select Materials when Combined with a Non-Thermal Plasma SAE paper 1999-01-3640 1999
- Hoard J. Balmer M.L. “Analysis of Plasma-Catalysis for Diesel NOx Remediation” SAE paper 982429 1998
- Penetrante B.M. Brusasco R.M. Merritt B.T. Vogtlin G. E. “Sulfur Tolerance of Selective Partial Oxidation of NO and NO 2 in a Plasma” SAE paper 1999-01-3687 1999
- Burch R. Sullivan J.A. Watling T.C. “Mechanistic considerations for the reduction of NOx over Pt/Al 2 O 3 and Al 2 O 3 catalysts under lean-burn conditions” Catal. Today 42 1998 13 23
- Penetrante B.M. Brusasco R.M. Merritt B.T. Pitz W.J. Vogtlin G. E. “Feasibility of Plasma Aftertreatment for Simultaneous Control of NOx and Particulates” SAE paper 1999-01-3637 1999
- Fisher G.B. DiMaggio C.L. Sommers J.W. “NOx Reactivity Studies of Prototype Catalysts for a Plasma-Catalyst Aftertreatment System” SAE paper 1999-01-3685 1999
- Deeba M. Feeley J. Farrauto R. “Lean NOx: dual sites for NOx reduction on Pt/H-ZSM-5” Appl. Catal. A 188 1999 219 227
- McLarnon C.R. Penetrante B.M. “Effect of Reactor Design on the Plasma Treatment of NOx” SAE paper 982434 1998
- Hamada H. “Selective reduction of NO by hydrocarbons and oxygenated hydrocarbons over metal oxide catalysts” Catalysis Today 22 1994 21 40
- Tabata M. et al. “Reduction of NOx in diesel exhaust with methanol over alumina catalyst” Appl. Catal. B: Environmental 6 1995 169 183