SAE/nternationa/"
`
`Journal of
`
`Fuels and Lubricants
`
`Volume 2 - Issue 1
`
`James E. Smith —- President
`
`Dr. Thomas W. Ryan Ill — 2008 President
`Jacqueline A. Dedo — Vice President Automotive
`Charla Wise — Vice President Aerospace
`Richard E. Kleine — Vice President Commercial Vehicle
`Terence J. Rhoades — Treasure
`
`Carol A. Story — Assistant Treasure
`David L. Schutt PhD — Executive Vice President and COO
`
`Published by: SAE International
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`BASF-2009.001
`
`

`
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`ISSN 1946-3952
`
`Copyright 2009 SAE international
`Printed in USA
`
`BASF-2009.002
`
`

`
`SAE International Journal of Fuels and Lubricants
`Table of Contents
`
`Diesel Emission Control in Review (2009—01—0121) .......................................................................................... ..1
`Timothy V. Johnson
`
`A Detailed Chemistry Multi-Cycle Simulation of a Gasoline Fueled
`HCCI Engine Operated with NVO (2009-01-0130) ........................................................................................... .. 13
`Jonathan Etheridge, Sebastian Mosbach, Markus Kraft, Hao Wu, and Nick Collings
`
`Premixed Low Temperature Combustion of Biodiesel and Blends in a
`High Speed Compression Ignition Engine (2009-01-0133) ............................................................................ ..28
`William F. Northrop, Stanislav V. Bohac, and Dennis N. Assanis
`
`A Study of GasoIine—Alcohol Blended Fuels in an Advanced
`Turbocharged DISI Engine (2009-01-0138) ...................................................................................................... ..41
`Alasdair Cairns, Phil Stansfield, Neil Fraser, Hugh Blaxill, Martin Gold, John Rogerson, and Craig Goodfellow
`
`Ethanol Flex-Fuel Engine Improvements with Exhaust Gas
`Recirculation and Hydrogen Enrichment (2009—01—0140) .............................................................................. .. 58
`Jess Gingrich, Terry Alger, and Brian Sullivan
`
`Dual SCR Aftertreatment for Lean N0x Reduction (2009—01-0277) ............................................................... .. 66
`Craig L. DiMaggio, Galen B. Fisher, Ken M. Rahmoeller, and Mark Sellnau
`
`Pollutants Emissions During Mild Catalytic DPF Regeneration in
`Lig ht-Duty Vehicles (2009-01-0278) ................................................................................................................. .. 78
`G. Villata, A. Tarabocchia, V. Bozzolini, J. Caroca, N. Russo, D. Fino, G. Saracco, and V. Specchia
`
`Biodiesel Effects on U.S. Light-Duty Tier 2 Engine and Emission
`Control Systems — Part 2 (2009-01-0281) ....................................................................................................... .. 88
`Marek Tatur, Harsha Nanjundaswamy, Dean Tomazic, Matthew Thornton, and Robert L. McCormick
`
`Fuel Economy: From Niche to Status-Quo Manufacturing (2009—01-0314) ................................................ .. 104
`Abigail Reid Mechtenberg
`
`Impact of Fuel Properties on the Performances and Knock Behavior of a Downsized
`Turbocharged Dl SI Engine —— Focus on Octane Numbers and Latent Heat
`of Vaporization (2009-01-0324) ....................................................................................................................... .. 118
`Jean Milpied, Nicolas Jeuland, Gabriel Plassat, Sabine Guichaoua, Nathalie Dioc,
`‘
`Alexandre Marchal, and Pierre Schmelzle
`
`Influence of Base Diesel Fuel upon Biodiesel Sludge Formation Tendency (2009-01-0482) ................... .. 127
`Mitsuru Osawa, Yuta Ebinuma, Syouji Sasaki, Tsuyumi Takashiba, Yusaku Takaki,
`Jeff J. Jetter, and Ulf Reinschmidt
`
`CARE — CAtalytic Reformated Exhaust Gases in Turbocharged
`DISI-Engines (2009-01-0503) ........................................................................................................................... .. 139
`Henrik Hoffmeyer, Emanuela Montefrancesco, Linda Beck, Jiirgen Willand,
`Florian Ziebart, and Fabian Mauss
`
`Model Predictive Control Approach for AFR Control during Lean
`NOx Trap Regenerations (2009-01-0586) .............................. .-. ....................................................................... .. 149
`Ming Feng Hsieh, Marcello Canova, and Junmin Wang
`
`BASF-2009.003
`
`

`
`The Optimization of the Light-Duty Automotive Fleet for
`Cost Effective Fuel Efficiency (2009—01-0595) ............................................................................................... .. 158
`Sandra P. Stojkovski
`
`Networked Clean Vehicles, How the Environment Information Will Improve
`Fuel Efficiency and CO2 Emissions (2009-01-0599) ..................................................................................... .. 167
`I. lglesias, L. Isasi, M. Larburu, A. Martin, and A. Pena
`‘
`
`Heated Injectors for Ethanol Cold Starts (2009-01-0615) ............................................................................. .. 172
`Daniel Kabasin, Kevin Hoyer, Joseph Kazour, Rudolf Lamers, and Tobias Hurter
`
`Key Parameters for Startability Improvement Applied to Ethanol Engines (2009-01-0616) ..................... .. 180
`C. Colpin, T. Leone, M. Lhuillery, and A. Marchal
`
`Sl Engine Hardware and Software Design for High Power, Low
`Emission Applications (2009-01-0617) .......................................................................................................... .. 189
`Adrian Brdarski, Justin Kern, David Woldring, Hakan Yilmaz, Mark Christie, and Klaus Muller-Haas
`
`Study of Ethanol-Blended Fuel (E85) Effects Under Cold-Start Conditions (2009-01-0620) .................... .. 196
`Koichiro Aikawa, Takayuki Sakurai, and Aruto Hayashi
`
`Impact and Prevention of Ultra-Low Contamination of Platinum Group
`Metals onSCR Catalysts Due to DOC Design (2009-01-0627) ...................................................................... .. 204
`Giovanni Cavataio, Hung-Wen Jen, James W. Girard, Douglas Dobson, James R. Warner,
`and Christine K. Lambert
`
`Effects of Rapid High Temperature Cyclic Aging on a Fully-Formulated
`Lean NOx Trap Catalyst (2009-01-0634) ........................................................................................................ .. 217
`Nathan A. Ottinger, Ke Nguyen, Bruce G. Bunting, Todd J. Toops, and Jane Howe
`
`Ethanol Detection in Flex-Fuel Direct Injection Engines Using in-Cylinder
`Pressure Measurements (2009-01-0657) ....................................................................................................... .. 229
`Nestor Oliverlo, Anna Stefanopoulou, Li Jiang, and Hakan Yilmaz
`
`Model Predictive Functional Control for an Automotive Three-Way Catalyst (2009-01-0728) ................. .. 242
`Robert W. Schallock, Kenneth R. Muske, and James C. Peyton Jones
`
`Malfunctions in Selected Emissions-Related Components of Euro
`4 Passenger Cars: Emissions Increase and OBD System Response (2009-01-0731) ............................... .. 250
`Dimitrios N. Tslnoglou and Zissis C. Samaras
`
`Coking Phenomena in Nozzle Orifices of DI-Diesel Engines (2009-01-0837)............................................. .. 259
`Jens Tang, Stefan Pischinger, Matthias Lamping, Thomas Korfer, Marek Tatur, and Dean Tomazic
`
`Diesel Lubricity Requirements of Future Fuel injection Equipment (2009-O1-0848) ................................. .. 273
`Markus Matzke, Ulrike Litzow, Andreas Jess, Rinaldo Caprotti, and Graham Balfour
`
`The Effects of Diesel Fuel Additives on Water Separation Performance (2009-01-0868) ......................... .. 287
`Gary Bessee and Scott Hutzler
`
`Procedure for Determining the Allowable Particle Contamination for
`Diesel Fuel injection Equipment (FIE) (2009-01-0870) .................................................................................. .. 294
`Alexander von Stockhausen, Martin P. Marigold, Dieter Eppinger, and Thomas C. Livingston
`
`BASF-2009.004
`
`

`
`Media for Water Separation from Biodiesel-Ultra Low Sulfur Diesel Blends (2009-01-0871) ................... .. 305
`F. Diani Pangestu and Christine M. Stanfel
`
`Diesel FuellWater Separation Test Methods — Where We Are and
`Where We Are Going (2009—01—0875) ............................................................................................................. .. 317
`Wally Stone, Gary Bessee, and Christine Stanfel
`
`The Poisoning and Desulfation Characteristics of Iron and
`Copper SCR Catalysts (2009-01-0900) ........................................................................................................... .. 324
`Joseph R. Theis
`
`SCR Catalyst Systems Optimized for Lightoff and Steady-State Performance (2009-01-0901) ............... .. 332
`Joseph R. Theis
`
`Laboratory Study of Soot, Propylene, and Diesel Fuel Impact on
`Zeolite-Based SCR Filter Catalysts (2009-01-0903) ...................................................................................... .. 342
`Giovanni Cavataio, James R. Warner, James W. Girard, Justin Ura, Douglas Dobson, and Christine K. Lambert
`
`Evaluation of SCR Catalyst Technology on Diesel Particulate Filters (2009-01-0910) ............................. .. 369
`Todd Ballinger, Julian Cox, Mahesh Konduru, Debnath De, Wendy Manning, and Paul Andersen
`
`Model Based Control of SCR Dosing and OBD Strategies with
`Feedback from NH3 Sensors (2009-01-0911) ................................................................................................ .. 375
`Andrew Herman, Ming-Cheng Wu, David Cabush, and Mark Shost
`
`Investigation of NOx- and PM-Reduction by a Combination of SCR-Catalyst and
`Diesel Particulate Filter for Heavy-Duty Diesel Engine (2009-01-0912) ...................................................... .. 386
`Michael Schaefer, Lothar Hofmann, Patrick Girot, and Renaud Rohe
`
`Cost and Fuel Efficient SCR-only Solution for Post-2010 HD
`Emission Standards (2009-01-0915) .............................................................................................................. .. 399
`Robert Cloudt, Frank Willems, and Peter van der Heijden
`
`Determination of PEMS Measurement Allowances for Gaseous Emissions
`
`Regulated Under the Heavy-Duty Diesel Engine In-Use Testing Program
`Part 3 — Results and Validation (2009-01-0938) ........................................................................................... ..407
`Christopher A. Sharp, Michael D. Feist, Christopher A. Laroo, and Matthew W. Spears
`
`Determination of PEMS Measurement Allowances for Gaseous Emissions
`
`Regulated Under the Heavy-Duty Diesel Engine In-Use Testing Program
`Part 2 —- Statistical Modeling and Simulation Approach (2009-01-0939) .................
`Janet P. Buckingham, Robert L. Mason, and Matthew W. Spears
`
`................................ ..422
`
`Determination of PEMS Measurement Allowances for Gaseous Emissions
`
`Regulated Under the Heavy-Duty Diesel Engine ln-Use Testing Program
`Part 1 —— Project Overview and PEMS Evaluation Procedures (2009-01-0940) .......................................... .. 435
`Michael D. Feisl, Christopher A. Sharp, and Matthew W. Spears
`
`Analysis of Butane Diffusion in Activated Carbon Canister (2009-01-0976) .............................................. ..455
`Koji Yamasaki, Tsugio Suzuki, Kazunari Sato, Noriyuki Kobayashi, Hiroyuki Tanaka, and Hiroshi Endo
`
`Fluoroelastomer Compatibility with Bioalcohol Fuels (2009-01-0994) ....................................................... .. 462
`Eric W. Thomas
`
`BASF-2009.005
`
`

`
`identification and Robust Control of LPG Fuel Supply System (2009-01-1025) ........................................ .. 474
`Umerujan Sawut, Gheyret Tohti, Buso Takigawa, Shinya Yamaguchi, Gensaku Konagai, and Teruo Tsuji
`
`Treatment of Vehicle Emissions from the Combustion of E85 and
`
`Gasoline with Catalyzed Hydrocarbon Traps (2009-01-1080) ...................................................................... ..485
`Jason A. Lupescu, Timothy B. Chanko, Joel F. Richeit, and Jason E. Devries
`
`Properties of Partial-Flow and Coarse Pore Deep Bed Filters Proposed to
`Reduce Particle Emission of Vehicle Engines (2009-01-1087) .................................................................... ..497
`A. Mayer, J. Czerwinski, P. Comte, and F. Jaussi
`
`Calibration and Validation of Various Commercial Particle Number
`
`Measurement Systems (2009-01-1115) .......................................................................................................... .. 512
`Barouch Giechaskiel, Massimo Carriero, Giorgio Martini, Alois Krasenbrink, and Daniel Scheder
`
`Research on Measurement Method of Road Gradient and Altitude by
`On-Road Driving (2009-01-1116) .................................................................................................................... ..531
`Susumu Sato, Toshiro Yamamoto, Yasuhiro Ogawa, and Noriko Fukuro
`
`Review of Prior Studies of Fuel Effects on Vehicle Emissions (2009-01-1181) ......................................... .. 541
`Albert M. Hochhauser
`
`Genetic Algorithm based Automated Calibration Tool for Numerical
`Selective Catalytic Reduction (SCR) Models (2009—O1—1265) ...................................................................... .. 568
`Praveen Chavannavar and J. Josh Driscoll
`
`Modeling the Emissions Control Performance of a Catalyzed Diesel
`Particulate Filter (CDPF) System for Light Duty Diesel Applications (2009—01—1266) ............................... .. 578
`Andrew P. E. York, Timothy C. Watling, Mehrdad Ahmadinejad, David Bergeal,
`Paul R. Phillips, and Daniel Swallow
`
`3D Numerical Study of Pressure Loss Characteristics and Soot Leakage
`Through a Damaged DPF (2009-01-1267) ...................................................................................................... ..590
`Xiaogang Zhang, Paul Tennison, and Tim Schram
`
`Hydrogen in Diesel Exhaust: Effect on Diesel Oxidation Catalyst Flow
`Reactor Experiments and Model Predictions (2009-01-1268) ...................................................................... .. 605
`Santhoji R. Katare and Paul M. Laing
`
`A Urea Decomposition Modeling Framework for SCR Systems (2009-01-1269) ....................................... .. 612
`Thomas L. McKinley and Andrew G. Alleyne
`
`Well-To-Wheels Energy Use and Greenhouse Gas Emissions of Plug-in
`Hybrid Electric Vehicles (2009-01-1309) ........................................................................................................ .. 627
`Amgad Elgowainy, Andrew Burnham, Michael Wang, John Molburg, and Aymeric Rousseau
`
`Analysis of the Correlation Between Engine-Out Particulates and Local 0) in the
`Lift-Off Region of a Heavy Duty Diesel Engine Using Raman Spectroscopy (2009-01-1357) .................. .. 645
`Ulf Aronsson, Clément Chartier, Oivind Andersson, Rolf Egnell, Johan Sjoholm, Mattias Richter, and Marcus Aldén
`
`Microscopic Visualization of PM Trapping and Regeneration in
`Micro-Structural Pores of a DPF Wall (2009-01-1476) .................................................................................. .. 661
`Preechar Karin, Liyan Cui, Pedro Rubio, Teppei Tsuruta, and Katsunori Hanamura
`
`BASF-2009.006
`
`

`
`Optimal Use of E85 in a Turbocharged Direct Injection Engine (2009-01-1490) ........................................ .. 670
`Robert A. Stein, Christopher J. House, and Thomas G. Leone
`
`Stratified Cold Start Sprays of Gasoline-Ethanol Blends (20o9—01—1496) .................................................. .. 683
`Stina Hemdal, Ingemar Denbratt, Petter Dahlander, and Jonas Warnberg
`
`Reconstruction of Time-Resolved Vehicle Emissions
`
`Measurements by Deconvolution (2009-01-1513) ......................................................................................... .. 697
`James D. Pakko
`
`Uncertainties in Filter Mass Measurements Made to Determine
`
`Compliance with the 2007 Diesel PM Standard (2009-01-1516) .................................................................. .. 708
`Jacob Swanson, David Kittelson, and David Dikken
`
`Factors Influencing Mass Collected During 2007 Diesel PM Filter Sampling (2009-01-1517) .................. ..718
`Jacob Swanson and David Kittelson
`
`Enabling Flex Fuel Vehicle Emissions Testing - Test Cell Modifications and
`Data Improvements (2009-01-1523) ................................................................................................................ .. 730
`Michael J. Loos, Joel F. O. Richert, Adolfo Mauti, Stephen Kay, Timothy Chanko, and Sandip D. Shah
`
`Optimizing Precision and Accuracy of Quantitative PLIF of Acetone as a
`Tracer for Hydrogen Fuel (2009-01-1534) ...................................................................................................... .. 737
`Victor M. Salazar, Sebastian A. Kaiser, and Fabien Halter
`
`Analysis of DPF lncombustible Materials From Volvo Trucks Using
`DPF-SCR-Urea with API CJ-4 and API Cl-4 PLUS Oils (2009-01-1781) ....................................................... .. 762
`James McGeehan, Sheila Yeh, James Rutherford, Melvin Couch, Bengt Otterholm,
`Andreas Hinz, and Andrew Walker
`
`Impacts of Biodiesel Fuel Blends Oil Dilution on Light-Duty
`Diesel Engine Operation (2009-01-1790) ....................................................................................................... .. 781
`Matthew J. Thornton, Teresa L. Alleman, Jon Luecke, and Robert L. McCormick
`
`An Experimental Investigation of the Origin of Increased NOx Emissions When
`Fueling a Heavy-Duty Compression-Ignition Engine with Soy Biodiesel (2009—01—1792) ........................ ..789
`Charles J. Mueller, André L. Boehman, and Glen C. Martin
`
`Fuel Effects on ion Sensing in a Homogeneous Charge Compression
`Ignition (HCCI) Engine (2009—O1-1805) ........................................................................................................... ..817
`Gregory E. Bogin,Jr., J. Hunter Mack, and Robert W. Dibble
`
`Performance and Emissions of a Diesel Engine Fueled by Biodiesel
`Derived from Different Vegetable Oils and the Characteristics of
`Combustion of Single Droplets (2009—01—1812) ............................................................................................ ..827
`Yasufumi Yoshimoto
`
`Evaluation of the Oxidation Stability of DieselIBiodiesel Blends Using the
`Modified Rancimat Method (2009—01—1828) ................................................................................................... .. 839
`George Karavalakis, Dimitrios Karonis, and Stamoulis Stournas
`
`Measuring Diesel Ash Emissions and Estimating Lube Oil Consumption Using a
`High Temperature Oxidation Method (2009-01-1843) ................................................................................... .. 850
`James Apple, David Gladis, Winthrop Watts, and David Kittelson
`
`BASF-2009.007
`
`

`
`US and EU Market Biodiesel Blends Quality Review — An OEM Perspective (2009-01-1850) ................. .. 860
`Pat Y. Geng, Andrew E. Buczynsky, and Anke Konzack
`
`Unregulated Harmful Substances in Exhaust Gas from Diesel Engines (20o9—01-1870) .......................
`Hideyuki Ogawa and Fumihiro Taga
`
`870
`
`Influence of High Injection Pressure on Diesel Fuel Stability: A Study of
`Resultant Deposits (2009-O1-1877) ................................................................................................................ .. 877
`Jim Barker, Paul Richards, Mark Goodwin, and Jonathan Wooler
`
`The Impact of Diesel and Biodiesel Fuel Composition on a Euro V HSDI
`Engine with Advanced DPNR Emissions Control (2009-01-1903) ............................................................... ..885
`D. L. Lance, C. L. Goodfellow, J. Williams, W. Bunting, I. Sakata, K. Yoshida, S. Taniguchi, and K. Kitano
`
`Effects of Ethanol Content on Gasohol PFI Engine
`Wide-Open-Throttle Operation (2009—01-1907) ............................................................................................. .. 895
`Kenneth Kar, Wai Cheng, and Kaoru lshii
`
`Model Based E85 Cold Start Optimization for DISI Engines (2009—01—1909) .............................................. .. 902
`S. Liebsch, O. Dingel, J. Maass, M. Gunther, M. Kratzsch, and S. Zwahr
`
`On the Main Factors Governing Auto-Ignition Phenomenon of Alcohol
`Spray — A Study from the View Point of Fuel Properties (2009—01—1931) .................................................. .. 911
`Hironori Saitoh and Kouji Uchida
`
`Modeling of Thermophoretic Soot Deposition and Hydrocarbon
`Condensation in EGR Coolers (2009—01-1939) .............................................................................................. ..921
`Mehdi Abarham, John Hoard, Dennis Assanis, Dan Styles, Eric W. Curtis, Nitia Ramesh,
`C. Scott Sluder, and John M. E. Storey
`
`Using Hythane as a Fuel in a 6-Cylinder Stoichiometric Natural-Gas Engine (2009-01-1950) ................. .. 932
`Mehrzad Kaladi, Per Tunestél, and Bengt Johansson
`
`Ethyl Tertiary Butyl Ether — A Review of the Technical Literature (2009-01-1951) .................................. .. 940
`Graeme Wallaoe, Jacques Blondy, Walter Mirabella, Ekkehard Schulte-Korne, and Jorma Viljanen
`
`Multiple Injection Strategy in a Direct-Injection Natural Gas Engine
`With Entrained Diesel (2009—01-1954) ............................................................................................................ ..953
`B. Scott Brown, Steven N. Rogak, and Sandeep Munshi
`
`Numerical Investigation of Non-Reacting and Reacting Diesel Sprays in
`Constant-Volume Vessels (2009-01-1971) ..................................................................................................... .. 966
`T. Lucchini, G. D’Errico, D. Ettorre, and G. Ferrari
`
`BASF-2009.008
`
`

`
`Evaluation of SCR Catalyst Technology on Diesel Particulate Filters
`
`Copyright © 2009 SAE International
`
`Todd Ballinger, Julian Cox, Mahesh Konduru, Debnath De,
`Wendy Manning and Paul Andersen
`Johnson Matthey, Inc.
`
`2009-01 -0910
`
`ABSTRACT
`
`Selective Catalytic Reduction (SCR) catalysts have been
`demonstrated as effective for controlling NOx emissions
`from diesel engines, maintaining high NOx conversion
`even after
`the extended high temperature exposure
`encountered in systems with active filter regenerations.
`As future diesel emission regulations are expected to be
`further
`reduced, packaging a large volume of SCR
`catalysts in diesel exhaust systems, along with DOC and
`particulate filter catalysts, will be challenging.
`One
`method to reduce the total volume of catalysts in diesel
`exhaust systems is
`to combine the SCR and DPF
`catalysts
`by
`coating SCR catalyst
`technology on
`particulate filters.
`In this work, engine evaluation of SCR
`coated filters has been conducted to determine the
`viability
`of
`the
`technology.
`Steady—state
`engine
`evaluations demonstrated that high NOx conversions
`can be achieved for SCR coated filters after high
`temperature oven aging. The effect of soot loading on
`back pressure as well as the time for soot regeneration
`was investigated for SCR coated filters and compared to
`conventional oxidative catalyst coatings. Hydrocarbon,
`CO, and NOx emission performance during a filter
`regeneration condition has also been evaluated. The
`SCR coated
`filter
`technology
`has
`also
`been
`demonstrated on several filter materials.
`
`INTRODUCTION
`
`To meet U.S. Tier 2 NOx emission requirements, many
`diesel engine manufacturers have chosen to use SCR
`catalysts with urea injection. Base metal urea—SCR
`catalysts have a wide temperature window of high NOx
`conversion and offer cost advantages compared to
`precious metal based NOx Adsorber Catalysts.
`
`Urea SCR emission systems for Tier 2 diesel vehicles
`will contain DOC, SCR, and CDPF catalysts in either
`DOC + SCR + CDPF or DOC + CDPF + SCR
`
`configuration. Each configuration has advantages and
`disadvantages; the choice of configuration will depend on
`such issues as the need for rapid |ight—off of the SCR, for
`maximizing passive regeneration,
`for adequate urea
`mixing, and for packaging space. The last issue is an
`especially important
`issue for smaller diesel vehicles
`such as passenger cars.
`
`Furthermore, new emission regulations will require even
`lower NOX emissions for diesel vehicles in the future.
`Under high exhaust flow conditions, the NOx conversion
`of SCR catalysts can be improved by increasing the
`volume of the catalyst (effectively reducing the space
`velocity).
`This will necessitate further
`increases in
`catalyst volumes causing packaging problems and
`increasing system costs.
`
`In order to meet the need for reducing packaging space
`or to increase catalyst volume within existing space,
`development work is being conducted to combine the
`SCR and filter functions by washcoating the filter with
`SCR catalysts.
`Previous work [1] demonstrated that
`SCR—DPF catalysts could achieve 86% NOx conversion
`during FTP cold—start
`tests,
`indicating that SCR—DPF
`catalysts have potential
`to meet
`low NOx emission
`requirements.
`
`However, SCR catalysts coated on filters must have high
`thermal
`durability
`to withstand
`repeated
`soot
`regenerations. Various investigations [2—4] have been
`undertaken to understand the deactivation of Cu-zeolite
`SCR catalysts since compared to other base metal
`zeolite catalysts, Cu—zeo|ite SCR catalysts are effective
`at converting NOx at low temperatures even in exhaust
`streams with low NO2 and can tolerate urea overdosing
`
`SAE Int. J. Fuels Lubr.
`
`| Volume 2 | Issue 1
`
`BASF-2009.009
`
`

`
`Steady-state tests were performed by running the engine
`at a constant speed and adjusting the load on the
`dynamometer to achieve inlet temperatures to the SCR-
`DPF from 205-440 “C.
`For the range of steady-state
`temperatures
`tested,
`the SCR—DPF space velocity
`ranged from 23—32K hr”;
`for LA-4 testing the space
`velocity ranged from 5-55K hr"; for US06 testing the
`space velocity ranged from 5—80K hr”. Urea injection
`was performed upstream of the SCR—DPF catalyst using
`a 32.5% urea solution and injecting at an ANR = 1. The
`catalysts were
`pre—saturated with
`ammonia before
`steady-state and transient testing by injecting urea at
`ANR = 1.5 at 200 “C. Regeneration experiments were
`performed by
`using
`post-injection to generate an
`exotherm in the DOC such that the filter temperature
`was 600-650 “C.
`
`NOx and CO emissions were measured using FTIR
`analyzers, HC emissions were measured using a HFID
`analyzer. Pressure measurements were made with a
`traditional pressure transducer.
`Soot
`loadings in the
`filters were measured by weighing the filters warm.
`
`RESULTS
`
`As indicated in the introduction section, in order for SCR-
`DPF catalysts to replace SCR + CDPF catalysts,
`the
`SCR—DPF must have high HC, CO, and NOx activity, low
`impact on back pressure, and must be able regenerate
`soot within a similar time compared to CDPF catalysts.
`
`SCR—DPF CATALYST NOx PERFORMANCE - The NOx
`conversion over advanced Cu—based SCR catalysts
`coated on cordierite and SiC filters after the 800 “C aging
`for 64 hours was measured as a function of temperature
`in steady-state testing on the engine. The SCR—DPF
`testing shown in Figure 1 was carried out with no/little
`soot on the filter. As expected for these advanced Cu
`SCR catalysts, high NOx conversion was measured
`across the temperature window. For both the SCR
`coated cordierite and SiC filters, the NOx conversion is
`greater than 90% in the temperature range from 200-440
`“C, showing that the NOx conversion is independent of
`the filter material. This demonstrates the potential for a
`DOC + SCR—DPF system to achieve Tier 2 emission
`requirements. When the amount of catalyst is reduced
`on the C650 filter (SCR C650 Reduced WCL), the NOx
`performance decreases slightly, as expected, but is still
`greater than 90% in the temperature range of 220-440
`“C. This indicates that there is the potential to further
`optimize the amount of SCR catalyst coated onto the
`filter without severely affecting NOx performance and
`consequently decrease the overall back pressure. The
`optimization for NOx performance and back pressure
`can be adjusted for each application and filter material.
`
`at high temperatures clue to lower selectivity in utilizing
`NH3 for NOx reduction. Partly as a result of this work,
`advances in the thermal durability of Cu-zeolite SCR
`catalysts have recently demonstrated durability up to 900
`“C [5,6]. These developments have greatly improved the
`chance of
`implementation for Cu based SCR—DPF
`catalysts, as these SCR catalysts can withstand a wide
`range of exhaust conditions, as well as demonstrating
`greater resistance to coking.
`
`In this work, advanced Cu—zeolite SCR catalysts have
`been
`coated
`on
`several
`high
`porosity
`filters
`to
`demonstrate the potential for DOC + SCR—DPF systems.
`Engine dynamometer testing was conducted on oven-
`aged filters to demonstrate that high NOx conversions
`are achievable after high temperature aging.
`In addition,
`since SCR—DPF catalysts would replace current CDPF
`catalysts,
`the
`SCR—DPF must
`also
`have
`similar
`characteristics as the CDPF catalyst in that it must have
`a low impact on back pressure and be able to regenerate
`soot in a comparable time as the CDPF. Thus, the SCR-
`DPF catalysts are also compared to a current production
`oxidative filter.
`
`EXPERIMENTAL
`
`Advanced Cu—zeo|ite SCR catalysts were washcoated on
`high porosity cordierite (C650) or SiC (MSC—14)
`filter
`substrate, 46.5 cells/cm2 (300 cells/inz) with 0.03048 cm
`(12 mil) wall thickness. The washcoat loading was the
`same for both filter types. An additional C650 filter was
`wash coated with 75% the washcoat loading (SCR C650
`Reduced WCL) of the other C650 filter to investigate the
`effect of lower washcoat loading on NOx activity and
`back pressure. These catalysts will be compared to a
`current oxidative filter catalyst (2008 MY oxidative filter
`catalyst) which was washcoated on standard SiC filter
`substrate, 31 cells/cmz (200 cells/inz) with 004064 cm
`(16 mil) wall thickness.
`
`All filter catalysts were hydrothermally aged in an oven at
`800 “C for 64 hours with 5% water to simulate long—term
`durability.
`This would represent the SCR—DPF being
`regenerated every 300 miles,
`spending 10 minutes
`during each regeneration at 800 “C over the required
`lifetime of an LDD diesel vehicle (120,000 miles).
`
`Testing was performed on a 2008 MY diesel engine
`mounted on a dynamometer, using a prototype 2010
`calibration. All tests were conducted using a DOC +
`SCR—DPF (or CDPF) configuration. Urea was injected
`after the DOC using an airless injector, and static mixers
`were utilized with a 1 meter length before the SCR—DPF
`to insure good mixing in the exhaust. The DOC used for
`testing was a Pt:Pd catalyst at 2:1 ratio, with total PGM
`loading of 2.7 g/L, and was aged 800 “C for 64 hours.
`SCR—DPF and CDPF catalyst volume was 2x engine
`displacement.
`
`370
`
`SAE Int. J. Fuels Lubr.
`
`| Volume 2 | Issue 1
`
`BASF-2009.010
`
`

`
`
`
`
`
`NOxconversion(%)
`
`90
`
`80
`
`70
`
`60
`
`50
`
`40
`
`30
`
`20
`
`10
`
`0
`
`"Iv SCR coated C650
`-w-- SCR coated MSC—14
`~A- SCR C650 Reduced WCL
`
`150
`
`200
`
`250
`
`350
`300
`Temperature (C)
`
`400
`
`450
`
`500
`
`Figure 1: Steady—state NOx conversion of aged SCR-
`DPF catalysts tested on engine.
`
`SOOT ON SCR-DPF CATALYST
`EFFECT OF
`PERFORMANCE — Since SCR catalysts coated on filters
`will end up in close contact or covered with soot, there is
`the potential that NOx performance could be affected by
`the soot layer.
`in order to test the impact of soot on the
`performance of the advanced SCR-DPF catalysts,
`the
`SCR coated C650 filter was tested with soot in the filter.
`The filter was rapidly soot
`loaded to achieve a soot
`loading of 2.0 g/L soot on the filter. The filter was then
`tested by running the steady—state NOX activity window
`test, as shown in Figure 2. The soot loaded filter has
`
`the advanced SCR-DPF catalyst
`the NOx activity of
`technology is not affected by soot,
`in agreement with a
`previous study [1]. The effect of soot loadings greater
`than 3 g/L was not conducted in this study, but will be
`investigated in future work to determine if higher soot
`loadings would affect performance.
`
`TRANSIENT TEST RESULTS FOR SCR-DPF — Hot LA-
`
`4 and US06 testing was also conducted on the DOC +
`SCR-DPF system to test the activity of the SCR-DPF
`catalysts under transient conditions. Before testing the
`catalyst system was pre—saturated with NH3 by injecting
`urea at 200 “C using ANR = 1.5, then running a LA—4 test
`with ANR = 1 to equilibrate NH3 storage. This procedure
`is expected to demonstrate the maximum conversion
`that could be achieved for this system. Table 1 shows
`that