Final Report Evaluation of the feasibility, cost-effectiveness, and necessity of equipping small off-road diesel engines with advanced PM and/or NOx aftertreatment Contract No. 14-300 Prepared for: Dr. Chris Ruehl California Air Resources Board Research Division 1001 I street Sacramento, CA 95812 (916) 323-1520 March 2019 Dr. Thomas D. Durbin, PI Dr. Wayne Miller, Co-PI Dr. Kent C. Johnson, Co-PI Dr. Georgios Karavalakis, Co-PI Dr. Luciana M. B. Ventura Mr. Jiacheng Yang Mr. Cavan McCaffery Dr. Chengguo Li Mr. Kurt Bumiller Mr. Daniel Sandez University of California CE-CERT Riverside, CA 92521 951-781-5791 951-781-5790 (fax) i Acknowledgments The authors thank the following organizations and individuals for their valuable contributions to this project. We acknowledge funding from the California Air Resources Board under contract 14-300. We acknowledge Mr. Mark Villa and Mr. Dany Gomez of the University of California, Riverside for their contributions in conducting the emissions testing for this program. ii Table of Contents Acknowledgments ......................................................................................................................... ii Table of Contents ......................................................................................................................... iii List of Tables ................................................................................................................................ vi List of Figures ............................................................................................................................. viii Abstract ...........................................................................................................................................x Executive Summary ................................................................................................................... xiii 1 Introduction ............................................................................................................................1 1.1 Early standards for nonroad equipment ............................................................................1 1.2 Standards after the 2014 model year .................................................................................2 1.3 Useful life ..........................................................................................................................3 1.4 Environmental Benefit and Cost .......................................................................................3 1.4.1 1998 Regulation .....................................................................................................3 1.4.2 Tier 4 Regulation ....................................................................................................3 1.4.3 California regulation..............................................................................................3 2 Objective ..................................................................................................................................4 3 Preliminary Evaluation of Emission Control Strategies .....................................................5 3.1 Characterization of Engines ..............................................................................................5 3.1.1 Engine Manufacturers ............................................................................................5 3.1.2 Equipment Types ....................................................................................................6 3.1.3 Engine Types ........................................................................................................10 3.2 Potential Emissions Control Strategies ...........................................................................14 3.2.1 NOx Control Strategies .........................................................................................14 3.2.1.1 Selective Catalytic Reduction (SCR) Technology .................................................................... 14 3.2.1.2 Lean-NOx Trap or NOx Adsorber Technology ......................................................................... 15 3.2.1.3 Lean-NOx Catalyst Technology ................................................................................................ 16 3.2.1.4 Engine Design NOx Control Technologies ............................................................................... 16 3.2.2 PM Control Strategies ..........................................................................................17 3.2.2.1 Diesel Particle Filters .............................................................................................................. 17 3.2.2.2 Flow-Through Filters............................................................................................................... 18 3.2.2.3 Diesel Oxidation Catalysts ...................................................................................................... 18 3.2.2.4 In-Cylinder PM Control ........................................................................................................... 20 3.3 Applicability of These Control Strategies to Small Off-Road Diesel Engines ...............20 3.3.1 Operating Temperatures ......................................................................................20 3.3.2 Durability .............................................................................................................20 3.3.3 Maintenance .........................................................................................................21 3.4 Feasibility of Control Strategies for Small Off-Road Diesel Engine Prototype Development and Demonstration ..............................................................................................21 3.4.1 Proventia ..............................................................................................................21 3.4.2 DCL DPF system for a mini-excavator ................................................................22 3.4.3 BASF/Continental/Donaldson SCR system for a ride mower ..............................23 3.4.4 Johnson Matthey/Tenneco SCRT for a skid steer ................................................24 3.4.5 Other Potential Demonstrations ..........................................................................25 iii 4 Emissions and Durability Testing .......................................................................................27 4.1 Experimental ...................................................................................................................27 4.1.1 Engines and Test Fuels ........................................................................................27 4.1.1.1 TRU Engine.............................................................................................................................. 28 4.1.1.2 Ride Mower Engine ................................................................................................................. 29 4.1.1.3 Excavator Engine ..................................................................................................................... 30 4.1.1.4 Skid Steer Engine ..................................................................................................................... 31 4.1.2 Engine Dynamometer Testing ..............................................................................32 4.1.2.1 Engine Dynamometer............................................................................................................... 32 4.1.2.2 General Test Sequence ............................................................................................................. 33 4.1.2.3 Engine Mapping ....................................................................................................................... 35 4.1.2.4 Test Cycles ............................................................................................................................... 38 4.1.3 Emissions Testing .................................................................................................43 4.1.4 Field Demonstrations and Additional Catalyst Aging .........................................43 4.2 Emissions Testing Results ...............................................................................................46 4.2.1 TRU Emissions Testing Results ............................................................................46 4.2.2 ide Mower Emissions Testing Results ..................................................................48 4.2.3 Mini-Excavator Emissions Testing Results ..........................................................55 4.2.4 Skid Steer Emissions Testing Results ...................................................................60 5 Cost/Benefit analysis of advanced emission control strategies for small off-road diesel engines ...........................................................................................................................................67 5.1 EPA 2004 Cost/Benefit Analysis ....................................................................................67 5.1.1 Cost Estimates ......................................................................................................67 5.1.2 Emission Inventory Estimates ..............................................................................71 5.1.3 Cost per Ton Estimates ........................................................................................75 5.2 Cost/Benefit Analysis for the implementation