Note from the Director...
Oak Ridge National Laboratory’s (ORNL) Fuels, Engines, and Emissions Research Center (FEERC), located at the National Transportation Research Center (NTRC) site, conducted R&D for multiple subprograms of the FreedomCAR and Vehicle Technologies Program (FCVT) in 2007, including Advanced Combustion Engines, Fuel Technologies, Vehicle Systems, and Health Impacts. Strong industry collaboration in FEERC was evidenced by the growth in CRADAs from four to seven in fuels/engine/emissions technology. An eighth CRADA is expected to be signed in FY 2008. Less-formal, yet very active collaborations with approximately 15 additional private-sector organizations and non-DOE agencies continued. In addition to the CRADAs, eight private-sector firms sponsored R&D at the Center in FY 2007, plus other Federal Agencies.
FEERC staff are highly engaged in supporting FreedomCAR and 21st Century Truck Partnership (21CTP) programmatic activities such as the Advanced Combustion and Emission Control tech team, the Diesel Crosscut Team, and the 21st Century Truck “Lab Council.” ORNL provides co-leadership with industry of the Cross-cut Lean Exhaust Emissions Reduction Simulation (CLEERS) activity. In fuels utilization, FEERC staff led the start up, and now co-chair, the Fuels for Advanced Combustion Engines (FACE) project being managed within the Coordinating Research Council (CRC).
In 2007, plans were realized for FEERC to support the Office of Biomass Programs (OBP) in research on barriers to ethanol deployment. In several projects co-sponsored by FCVT and OBP, FEERC supported the President’s 20-in-10 initiative. These efforts, all new in FY 2007, included:
- Literature review of barriers to using ethanol blends higher than 10% in the legacy fleet of non-FFVs.
- Experiments with intermediate blends of ethanol in small non-road engines
- Start up of vehicle tests with intermediate blends
- Characterization of the Saab Biopower FFV
- Materials compatibility research for E85 dispensers in support of Underwriters Lab certification process
Research Facilities
The research facilities and capabilities in FEERC were improved in FY 2007, with the following examples:
- Two new electronic engine control prototyping systems. Two 1.9 liter GM diesel engines that were sent to ORNL last year are now functional with powerful electronic engine management systems.
- Seventh engine cell area being prepared. An additional industry partner has already provided an engine for research on materials issues in high-efficiency engines. At the NTRC site, lab space for a seventh engine cell was cleared of an older experiment. A bed plate is available from a previous lab site. ORNL facilities funding has been acquired to prepare infrastructure.
- New engine research platform from industry WFO customer. Is fully operational and available for use on DOE funded R&D in addition to proprietary R&D.
- Second bench reactor for emission control catalysis research. A second bench flow reactor was commissioned to handle efforts required by CLEERS and partner projects.
Key Technical Accomplishments
Joule Light-Duty Engine Efficiency 2007 Milestone Completed. ORNL team reached 42% thermal efficiency milestone on two engine platforms. Second Law of thermodynamics calculations were added to Ricardo WAVE model to guide paths to 45% 2010 target. This effort involved setting up new engines and control systems. ORNL continues to be the most focused lab on the subject of engine efficiency. They have effectively integrated several projects in combustion, emission controls, and advanced thermodynamic studies to achieve the efficiency and emissions targets, including capturing key results from other DOE labs and key universities. Industry partners have been identified with technology to assist in the longer range goals.
Progress in High Efficiency Clean Combustion (HECC). Conducted advanced combustion R&D at the multi-cylinder engine scale using their electronic engine management tools and expertise and exhaust chemical analysis capability. This research complements work elsewhere in fundamental single-cylinder research engines. ORNL helped explain the opportunities and limits of high-pressure and low-pressure EGR on expanding the operating load range of HECC from nominally 4.5 bar to 5.0 bar without a loss of efficiency. We analyzed the emissions data in a way to estimate that minimal NOx aftertreatment would be needed to meet Tier 2 Bin 5 FTP emissions levels if HECC could be used in this range (SAE Paper 2006-01-3311). These findings were used in FreedomCAR Advanced Combustion and Emission Control (ACEC) tech team highlights.
Dual-mode HCCI-SI combustion. In gasoline-based HCCI, ORNL identified a stable hybrid combustion mode in between HCCI and SI where highly unstable combustion was typical. Using chemical kinetic models, the underlying reasons for the instability are becoming clarified. To carry these findings into practice, a CRADA with Delphi has been formed.
Pivotal technical contributions to industry partners. Contributions by ORNL to the successful launch of new Cummins diesel engine were cited in letters of thanks from Cummins Chief Technical Officer (CTO). Further, a new diagnostic method was proven for near-real-time detection of oil dilution by fuel impingement on cylinder walls. Both accomplishments were achieved under a CRADA with Cummins.
Comprehensive Studies of Fuel Effects on Advanced Combustion Regimes.
ORNL is engaged in probably the broadest set of investigations in the DOE system on fuel effects on advanced combustion regimes. They have achieved and characterized combustion modes such as HCCI or HECC with a variety of blended petroleum fuels, biodiesel blends, oils sands fuels, and ethanol blends (see additional info below). ORNL was the primary thought leader in starting the Fuels for Advanced Combustion Engines (FACE) activity and has continued to have leadership roles in the ongoing program. In FY 2007 a systematic study of a set of oil sands fuels was completed.
Biodiesel fuel effects on soot chararacteristics and filter regeneration. A unique microreactor was developed and used to study how biodiesel effects soot oxidation kinetics.
Innovations and knowledge discovery in NOx emissions controls.
Significant achievements included:
- Identified the consumption of ammonia by oxygen storage capacity as a cause of low ammonia breakthrough on a commercial lean NOx trap (LNT) and verified mechanism in diesel exhaust with studies on a light-duty diesel engine with in-cylinder regeneration.
- Characterized the combined fuel efficiency and emissions performance of a lean NOx trap catalyst for multiple modes of engine operation including advanced modes such as high efficiency clean combustion.
- Developed a chemical kinetics mechanism to predict ammonia and nitrous oxide generation during lean NOx trap regeneration. (SNL and ORNL)
- Elucidated and proposed a conceptual model on how sulfation develops along a lean NOx trap, affects spatial distribution of reactions, and results in global performance changes.
- Identified significantly higher sulfation/degradation rate for oxides of nitrogen (NOx) storage capacity than for oxygen storage capacity, resulting in more plug-like sulfation of NOx storage capacity.
- Using unique spectroscopy methods in conjunction with micro-reactor evaluations, identified ceria as an active participant in NOx storage and reduction leading to improved performance at low temperatures.
- Using bench-core reactor, corroborated low temperature improvement and identified that adding ceria to LNTs leads to a decrease in NH3 emissions.
- Demonstrated that sulfur has mobility on the surface and that it can adsorb on one site and migrate to other sites.
- Demonstrated that fully formulated catalysts (with ceria) release sulfur primarily in the form of H2S during rich-only desulfation; model catalysts release both H2S and SO2. Switching to lean after rich sulfation causes the release of significant SO2, which demonstrates both lean and rich conditions are necessary to fully remove sulfur.
- Developed rapid thermal aging techniques for LNTs that mimic reported material effects in engine-aged systems. Data being used to generate model of deactivation over the lifetime of a LNT.
- Demonstrated both SCR and LNT systems appear to be capable of meeting the requirements of H2 internal combustion engines (ICEs) when operating under optimal efficiency.
- Leading the CLEERS effort overall, perhaps the most dynamic forum in the emission control catalyst technical community. Major role in organizing and communicated the CLEERS priority poll which is likely to clarify the priority of LNT R&D for lean gasoline and the need to do more integrated device modeling for both diesel and lean gasoline aftertreatment.
- The CLEERS (Cross-cut Lean Exhaust Emissions Reduction Simulation) team continued collaboration that has provided a framework for data sharing among Crosscut Team members for urea-SCR and diesel particle filter technologies, as well as LNTs.
- ORNL maintained the website and organized the Ninth CLEERS (Cross-cut Lean Exhaust Emissions Reduction Simulation, http://www.cleers.org) workshop.
- Multiple key contributions to ethanol vehicle studies in support of 20-in-10.
- Acquired and characterized Saab Biopower (OBP prime sponsor)
- Teamed with NREL to develop test plan for small non-road engines and initiated tests on intermediate ethanol blends
- Developed test plan for vehicle test, including contracting for data analysis
- Advanced E85 Vehicle research. Conducted vehicle-based studies of lean-burn ethanol and formed a new CRADA with Delphi on advanced E85 engines.
- Completed further experiments and published results of fuel and lubricant constituents effects on catalyst emission control aging and degradation. A strong contribution to development of accelerated aging protocols. New finding that soot layer is key deactivator of oxycat performance.
- Health Impacts, Real-world Emissions Studies. As part of the health effects subprogram, UV, LIDAR, and acoustic remote sensing techniques were deployed at a weigh station on I-40/75 to measure NOx, PM, and engine parameters, respectively, of heavy-duty trucks pulling away from the weigh station. Truck weights were also recorded. The real-world emission results from the study will improve and expand the database for heavy-duty trucks as a function of truck weight and speed/acceleration. The database is invaluable for modeling of air quality through models such as EPA’s MOVES (motor vehicle emissions simulator) model. The field-emissions research team also conducted two campaigns in Texas, studying the emissions levels of idling or creep-idling trucks at the US-Mexican border. New data were also generated on the idling emissions of a new 2007 DPF-equipped truck for comparison to APUs.
- Vehicle Systems. FEERC developed comprehensive computational submodels describing physical and chemical mechanisms in exhaust aftertreatment devices, for incorporation in powertrain systems analysis toolkit software (PSAT). An engine map for PSAT was developed that represents a modern engine operating in low-temperature combustion at light loads and conventional combustion at over about 40% load.
The accomplishments mentioned above were recorded in approximately 90 papers and presentations at technical conferences and for journals, as well as Working Group Meetings. Many were presentations invited by various industry firms, academia, and other technical institutions, several at international meetings.
Direct Support to Industry (work-for others).
ORNL FEERC performed direct funded work for eight firms in FY 2007. Typically these efforts are proprietary and are not publicized.
Thanks for visiting our website. If you have specific questions or comments about anything you see here, please do not hesitate to contact the PI or me.
