Combustion and Emission Control
Combustion and Emission Control R&D activity focuses on developing enabling technologies for engines operating in advanced combustion regimes, such as homogeneous charge compression ignition (HCCI) and other modes of low-temperature combustion (LTC). Operation at these combustion modes will increase engine efficiency beyond current advanced diesel engine efficiencies, and reduce engine emissions of nitrogen oxides (NOx) and particulate matter (PM) to near-zero levels.
Advanced combustion engines will power energy-efficient, clean passenger and commercial vehicles using clean, hydrocarbon (petroleum- and non-petroleum-based) fuels. The near-zero levels of engine-out emission will greatly reduce the need for exhaust aftertreatment that typically utilizes precious metals. Lower-cost emission control systems with little or no energy consumption and greater durability can result in potentially less expensive engines, thereby overcoming key technical barriers of emissions and cost.
Research Goals
- Improve passenger vehicle engine efficiency 25%-40% by 2014
- Improve commercial vehicle engine efficiency at least 20% by 2014
- Achieve engine cost, durability, and emissions targets
Approach
A balanced, integrated activity (from applied research to technology development) is undertaken to advance the technologies for cleaner and more energy-efficient advanced combustion engines, fuel(s), and systems. The approach is to simultaneously address in-cylinder combustion, exhaust aftertreatment, and fuel formulation to arrive at the most cost-effective approach to optimizing advanced combustion engine efficiency and performance while reducing emissions to near-zero levels.
![]() |
![]() |
Spatially resolved, capillary-inlet mass spectrometer allows in-situ studies of emission control catalyst reactions inside the device. (Two sizes of capillaries are shown). The ORNL-developed instrument was winner of R&D 100 award in 2008.
Our well-balanced R&D efforts range from fundamental research to prototype demonstration, informed at each stage by industry partners who help identify critical barriers to technology commercialization. National laboratories and universities conduct fundamental and applied research aimed at understanding combustion processes, pollutant formation, and emissions reduction. Small companies and suppliers conduct research on enabling technologies for fuel and air systems, engine controls, sensors and other engine technologies. The deep insights and accurate models developed through this research guide the development of advanced engine designs that allow expanded use of high-efficiency clean combustion strategies. Fundamental knowledge and advanced enabling technologies are incorporated into production-ready engine designs through cost-shared applied R&D and demonstration activities conducted by engine manufactures in response to competitive solicitations.
We also fund research to ensure that widespread commercialization of new technologies is safe for human health and the environment. Health impacts research is conducted to ensure that unintended consequences to human health are avoided as industry proceeds to commercialization of these technologies. Potential impacts are indentified and a scientific and rational basis for minimizing these impacts is provided before new technologies are widely implemented in transportation vehicles.
CLEERS (crosscut lean-exhaust emission reduction simulation) is a forum for informaton development to enable improved models of emission control catalysts and devices. The graphic illustrates combined flow and temerature computations during cold-start of a catalytic converter.
Microscopic analysis techniques on a lean NOx trap catalyst elucidate mechanisms of poisoning by Sulfur (green images).
![]() |
![]() |
|
Optical Engine |
Engine Simulation |
.jpg)
.jpg)

