0
Research Papers: Internal Combustion Engines

Rapidly Pulsed Reductants for Diesel NOx Reduction With Lean NOx Traps: Comparison of Alkanes and Alkenes as the Reducing Agent

[+] Author and Article Information
Amin Reihani

Department of Mechanical Engineering,
University of Michigan,
G.G. Brown Laboratory, 2350 Hayward,
Ann Arbor, MI 48109
e-mail: areihani@umich.edu

Brent Patterson

Department of Chemical Engineering,
University of Michigan,
3074 H.H. Dow 2300, Hayward Street,
Ann Arbor, MI 48109-2136
e-mail: patbre@umich.edu

John Hoard

Department of Mechanical Engineering,
University of Michigan,
1231 Beal Avenue,
1012 Lay Autolab, Ann Arbor, MI 48109
e-mail: hoardjw@umich.edu

Galen B. Fisher

Department of Chemical Engineering,
University of Michigan,
3170 H.H. Dow 2300, Hayward Street,
Ann Arbor, MI 48109-2136
e-mail: gbfisher@umich.edu

Joseph R. Theis

Ford Motor Company,
2101 Village Road,
Dearborn, MI 48124
e-mail: jtheis@ford.com

Christine K. Lambert

Ford Motor Company,
2101 Village Road,
Dearborn, MI 48124
e-mail: clamber9@ford.com

1Corresponding author.

Contributed by the IC Engine Division of ASME for publication in the JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER. Manuscript received February 16, 2017; final manuscript received February 27, 2017; published online April 25, 2017. Editor: David Wisler.

J. Eng. Gas Turbines Power 139(10), 102805 (Apr 25, 2017) (7 pages) Paper No: GTP-17-1068; doi: 10.1115/1.4036295 History: Received February 16, 2017; Revised February 27, 2017

Lean NOx traps (LNTs) are often used to reduce NOx on smaller diesel passenger cars where urea-based selective catalytic reduction (SCR) systems may be difficult to package. However, the performance of LNTs at temperatures above 400 °C needs to be improved. Rapidly pulsed reductants (RPR) is a process in which hydrocarbons are injected in rapid pulses ahead of the LNT in order to improve its performance at higher temperatures and space velocities. This approach was developed by Toyota and was originally called Di-Air (diesel NOx aftertreatment by adsorbed intermediate reductants) (Bisaiji et al., 2011, “Development of Di-Air—A New Diesel deNOx System by Adsorbed Intermediate Reductants,” SAE Int. J. Fuels Lubr., 5(1), pp. 380–388). Four important parameters were identified to maximize NOx conversion while minimizing fuel penalty associated with hydrocarbon injections in RPR operation: (1) flow field and reductant mixing uniformity, (2) pulsing parameters including the pulse frequency, duty cycle, and magnitude, (3) reductant type, and (4) catalyst composition, including the type and loading of precious metal and NOx storage material, and the amount of oxygen storage capacity (OSC). In this study, RPR performance was assessed between 150 °C and 650 °C with several reductants including dodecane, propane, ethylene, propylene, H2, and CO. Under RPR conditions, H2, CO, C12H26, and C2H4 provided approximately 80% NOx conversion at 500 °C; however, at 600 °C the conversions were significantly lower. The NOx conversion with C3H8 was low across the entire temperature range. In contrast, C3H6 provided greater than 90% NOx conversion over a broad range of 280–630 °C. This suggested that the high-temperature NOx conversion with RPR improves as the reactivity of the hydrocarbon increases.

FIGURES IN THIS ARTICLE
<>
Copyright © 2017 by ASME
Your Session has timed out. Please sign back in to continue.

References

Stanton, D. , Charlton, S. , and Vajapeyazula, P. , 2013, “ Diesel Engine Technologies Enabling Powertrain Optimization to Meet U.S. Greenhouse Gas Emissions,” SAE Int. J. Engines, 6(3), pp. 1757–1770. [CrossRef]
Heywood, J. B. , 1988, Internal Combustion Engine Fundamentals, McGraw-Hill, New York.
Johnson, T. , 2013, “ Vehicular Emissions in Review,” SAE Int. J. Engines, 6(2), pp. 699–715. [CrossRef]
Johnson, T. V. , 2007, “ Diesel Emission Control in Review,” SAE Paper No. 2007-01-0233.
Johnson, T. V. , 2008, “ Diesel Emission Control in Review,” SAE Technical Paper No. 2008-01-0069.
Takahashi, N. , Shinjoh, H. , Iijima, T. , Suzuki, T. , Yamazaki, K. , Yokota, K. , Suzuki, H. , Miyoshi, N. , Matsumoto, S.-I. , and Tanizawa, T. , 1996, “ The New Concept 3-Way Catalyst for Automotive Lean-Burn Engine: NOx Storage and Reduction Catalyst,” Catal. Today, 27(1–2), pp. 63–69. [CrossRef]
Olsson, L. , Blint, R. J. , and Fridell, E. , 2005, “ Global Kinetic Model for Lean NOx Traps,” Ind. Eng. Chem. Res., 44(9), pp. 3021–3032. [CrossRef]
Sharma, M. , Harold, M. , and Balakotaiah, V. , 2005, “ Analysis of Periodic Storage and Reduction of NOx in Catalytic Monoliths,” Ind. Eng. Chem. Res., 44(16), pp. 6264–6277. [CrossRef]
Roy, S. , and Baiker, A. , 2009, “ NOx Storage–Reduction Catalysis: From Mechanism and Materials Properties to Storage–Reduction Performance,” Chem. Rev., 109(9), pp. 4054–4091. [CrossRef] [PubMed]
Bisaiji, Y. , Yoshida, K. , Inoue, M. , Umemoto, K. , and Fukuma, T. , 2011, “ Development of Di-Air—A New Diesel deNOx System by Adsorbed Intermediate Reductants,” SAE Int. J. Fuels Lubr., 5(1), pp. 380–388. [CrossRef]
Li, Y. , Roth, S. , Dettling, J. , and Beutel, T. , 2001, “ Effects of Lean/Rich Timing and Nature of Reductant on the Performance of a NOx Trap Catalyst,” Top. Catal., 16(1–4), pp. 139–144. [CrossRef]
Dujardin, C. , Kouakou, A. , Fresnet, F. , and Granger, P. , 2013, “ Reaction Pathways for Ammonia Formation on Lean NOx Trap/Reduction System: A Spectroscopic Infrared Investigation,” Top. Catal., 56(1), pp. 151–156. [CrossRef]
Larson, R. S. , Pihl, J. A. , Chakravarthy, V. K. , Toops, T. J. , and Daw, C. S. , 2008, “ Microkinetic Modeling of Lean NOx Trap Chemistry Under Reducing Conditions,” Catal. Today, 136(1–2), pp. 104–120. [CrossRef]
Granger, P. , Lecomte, J. , Dathy, C. , Leclercq, L. , and Leclercq, G. , 1998, “ Kinetics of the CO+ NO Reaction Over Rhodium and Platinum–Rhodium on Alumina—II: Effect of Rh Incorporation to Pt,” J. Catal., 175(2), pp. 194–203. [CrossRef]
Bisaiji, Y. , Yoshida, K. , Inoue, M. , Takagi, N. , and Fukuma, T. , 2012, “ Reaction Mechanism Analysis of Di-Air-Contributions of Hydrocarbons and Intermediates,” SAE Int. J. Fuels Lubr., 5(3), pp. 1310–1316. [CrossRef]
Inoue, M. , Bisaiji, Y. , Yoshida, K. , Takagi, N. , and Fukuma, T. , 2013, “ deNOx Performance and Reaction Mechanism of the Di-Air System,” Top. Catal., 56(1–8), pp. 3–6. [CrossRef]
Perng, C. C. , Easterling, V. G. , and Harold, M. P. , 2014, “ Fast Lean-Rich Cycling for Enhanced NOx Conversion on Storage and Reduction Catalysts,” Catal. Today, 231, pp. 125–134. [CrossRef]
Zheng, Y. , Li, M. , Harold, M. , and Luss, D. , 2015, “ Enhanced Low-Temperature NOx Conversion by High-Frequency Hydrocarbon Pulsing on a Dual Layer LNT-SCR Catalyst,” SAE Int. J. Engines, 8(3), pp. 1117–1125. [CrossRef]
Reihani, A. , Corson, B. , Hoard, J. W. , Fisher, G. B. , Smirnov, E. , Roemer, D. , Theis, J. , and Lambert, C. , 2016, “ Rapidly Pulsed Reductants in Diesel NOx Reduction by Lean NOx Traps: Effects of Mixing Uniformity and Reductant Type,” SAE Int. J. Engines, 9(3), pp. 1630–1641. [CrossRef]
West, B. , Huff, S. , Parks, J. , Lewis, S. , Choi, J.-S. , Partridge, W. , and Storey, J. , 2004, “ Assessing Reductant Chemistry During In-Cylinder Regeneration of Diesel Lean NOx Traps,” SAE Technical Paper No. 2004-01-3023.
Pukelsheim, F. , 1994, “ The Three Sigma Rule,” Am. Stat., 48(2), pp. 88–91.
Granger, P. , Dhainaut, F. , Pietrzik, S. , Malfoy, P. , Mamede, A.-S. , Leclercq, L. , and Leclercq, G. , 2006, “ An Overview: Comparative Kinetic Behaviour of Pt, Rh and Pd in the NO+ CO and NO+ H2 Reactions,” Top. Catal., 39(1–2), pp. 65–76. [CrossRef]
Lesage, T. , Verrier, C. , Bazin, P. , Saussey, J. , Malo, S. , Hedouin, C. , Blanchard, G. , and Daturi, M. , 2004, “ Comparison Between a Pt–Rh/Ba/Al2O3 and a Newly Formulated NOx-Trap Catalysts Under Alternate Lean–Rich Flows,” Top. Catal., 30(1–4), pp. 31–36. [CrossRef]
DiGiulio, C. D. , Pihl, J. A. , Choi, J.-S. , Parks, J. E. , Lance, M. J. , Toops, T. J. , and Amiridis, M. D. , 2014, “ NH3 Formation Over a Lean NOx Trap (LNT) System: Effects of Lean/Rich Cycle Timing and Temperature,” Appl. Catal. B: Environ., 147, pp. 698–710. [CrossRef]
Pihl, J. A. , Parks, J. E. , Daw, C. S. , and Root, T. W. , 2006, “ Product Selectivity During Regeneration of Lean NOx Trap Catalysts,” SAE Technical Paper No. 2006-01-3441.
Zheng, J. , Strohm, J. J. , and Song, C. , 2008, “ Steam Reforming of Liquid Hydrocarbon Fuels for Micro-Fuel Cells. Pre-Reforming of Model Jet Fuels Over Supported Metal Catalysts,” Fuel Process. Technol., 89(4), pp. 440–448. [CrossRef]
Burch, R. , and Millington, P. , 1995, “ Selective Reduction of Nitrogen Oxides by Hydrocarbons Under Lean-Burn Conditions Using Supported Platinum Group Metal Catalysts,” Catal. Today, 26(2), pp. 185–206. [CrossRef]
Burch, R. , Breen, J. , and Meunier, F. , 2002, “ A Review of the Selective Reduction of NOx With Hydrocarbons Under Lean-Burn Conditions With Non-Zeolitic Oxide and Platinum Group Metal Catalysts,” Appl. Catal. B: Environ., 39(4), pp. 283–303. [CrossRef]
Hepburn, J. , Kenney, T. , McKenzie, J. , Thanasiu, E. , and Dearth, M. , 1998, “ Engine and Aftertreatment Modeling for Gasoline Direct Injection,” SAE Technical Paper No. 982596.
Theis, J. R. , Ura, J. A. , and McCabe, R. W. , 2007, “ The Effects of Platinum and Rhodium on the Functional Properties of a Lean NOx Trap,” SAE Technical Paper No. 2007-01-1055.

Figures

Grahic Jump Location
Fig. 2

Graphical definition of pulse duty cycle (DC)

Grahic Jump Location
Fig. 3

NOx conversion curves of RPR using different reductants at concentrations listed in Table 3, and pulsing parameters: P = 3 s, DC = 15%, and λpulse = 0.75

Grahic Jump Location
Fig. 4

(a) NOx conversion and (b) ethylene conversion curves using ethylene as the reductant at concentrations listed in Table 3, different pulsing periods, DC = 15%, and λpulse = 0.75 using a degraded LNT sample

Grahic Jump Location
Fig. 5

(a) Ammonia selectivity and (b) CO out concentration using ethylene as the reductant at concentrations listed in Table 3, different pulsing periods of P = 1 s, 3 s, 10 s, DC = 15%, and λpulse = 0.75

Grahic Jump Location
Fig. 6

NOx conversion using dodecane as the reductant at concentrations listed in Table 3, at different pulsing periods, DC = 15%, and λpulse = 0.75

Grahic Jump Location
Fig. 1

Schematics of the RPR test rig

Grahic Jump Location
Fig. 7

(a) Ammonia selectivity and (b) CO out concentration using vaporized dodecane as the reductant at concentrations listed in Table 3, different pulsing periods of P = 1 s, 2 s, 3 s, 6 s, DC = 15%, and λpulse = 0.75

Grahic Jump Location
Fig. 8

(a) NOx and propylene conversion and (b) CO concentration and NH3 selectivity using propylene as the reductant at concentrations listed in Table 1, P = 3 s, DC = 15%, and λpulse = 0.75

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In