Project at a Glance
Project Status: complete
Title: Diesel particulates destruction by electrical discharge technique
Principal Investigator / Author(s): Yang, Lien C
Contractor: Jet Propulsion Laboratory, California Institute of Technology
Contract Number: A0-047-32
Research Program Area: Emissions Monitoring & Control
Topic Areas: Stationary Sources
This report summarizes the results of a research and development effort on a new technique which can destroy the particulates produced by a diesel engine powered vehicle. Close-spaced, comb-shaped electrodes are charged alternately by high voltage of opposite polarities. When the engine exhaust carrying the particulates flows through the electrodes, the particulates trigger spark discharges in the latter, which in turn destroy the particulate. A prototype hardware study has demonstrated the following:
(1) The technique is very effective in destroying the particulates if they have agglomerated into large size particles, several micrometers or larger in diameter. Destruction efficiency as high as 70 percent has been observed. This figure could be further improved if the hardware design is optimized.
(2) The major product of the destruction process is the carbon dioxide. The amount of other gaseous products such as carbon monoxide, hydrocarbons, NOx, and ozone produced by the process is small. The rates of these emissions by a full-scale particulates destruction device are estimated to be 20 to 100 times smaller than those specified by the U.S. Environmental Protection Agency for the light duty vehicles.
(3) The electrical power required to operate such a destruction device is small and is affordable by light duty vehicles. For a moderate particulate emission or destruction rate, the electrical power required can be made to be 50 watts or less. This high power efficiency is attributed to the release of energy by the particulates through their own fast combustion.
(4) A key problem has been identified; that is, how to dynamically agglomerate the particulates. Several ideas, such as self-release filters and a fluidized bed particulates agglomerator, have been explored and further effort is required in order to perfect a device for the agglomeration of the particulates.
For questions regarding research reports, contact: Heather Choi at (916) 322-3893
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