Particle Matter Generation and Characterization Control Using FOCAS® HGTR®, 03-R9799

Principal Investigators
Cynthia C. Webb
John W. Miller

Inclusive Dates:  04/01/08 – Current

Background - The FOCAS® HGTR® system is a diesel-fueled burner used to expose full-size diesel emission system components to simulated diesel exhaust gas. Completion of a recent IR&D project (03-R9687) gave the FOCAS HGTR the ability to provide close loop control on both water vapor and NO_x concentration in the exhaust gas stream.

This investigation concentrated on expanding the system's capability to provide a means for generating and controlling the rate and composition of particulate matter (PM) in the exhaust stream produced by FOCAS HGTR. This capability will expand the system functionality to include the ability to provide soot for loading and a means for regenerating diesel particulate filters (DPFs).

Approach - The investigation was divided into two phases. Phase I included several parallel tasks that provide in-depth understanding about typical PM composition generated from a current technology heavy duty diesel engine and the PM generation characteristics of the modified FOCAS HGTR system. During Phase II, the carbon and solid organic fraction (SOF) portions of typical engine-out PM composition were simulated. A secondary diesel burner was developed and operated independently from the FOCAS HGTR burner to generate carbon PM, while an oil injection system was built to introduce the SOF portion. Each system component was operated independently to demonstrate PM composition and mass rate control. The system was characterized for both carbon and SOF rate, composition, and particle size.

Accomplishments - The PM-burner hardware prototype developed under this work presented reasonable durability under the testing conducted. Also, the work conducted with the system has demonstrated that offline PM generation is feasible and that the potential exists for rate and SOF control. It was found that the PM generation rates are on the order of the mid-range of PM generation rates observed from an on-highway diesel engine. The initial PM sizing results also showed similar size distributions to the size distributions measured in the engine exhaust. The PM-burner for carbon with oil injection for SOF approach demonstrated similar SOF fractions measured from engine exhaust. The development of an off-line PM generation system was shown to be a viable approach to augmenting the exhaust produced by the FOCAS HGTR with PM. The current design level of the PM-burner hardware developed during this project is prototype and is not equipped to meet commercial needs, but it provides a good basis for developing a commercially viable system. An offline PM generator has the potential for augmenting engine as well as burner exhaust, thereby expanding the potential market for such a device.

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