Pulsed Plasma Processing of Diesel Engine Exhaust Final Report CRADA No. TC-0336-92-1-C
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Cummins Engine Company, Inc., Columbus, IN (United States)
The goal was to develop an exhaust-gas treatment process for the reduction of NOx and hydrocarbon from diesel engines. The project began believing that direct chemical reduction on NOx was possible through the use of non-thermal plasmas. The original CRADA began in 1993 and was scheduled to finish in 1996. It had as its goals three metrics: 1) remove two grams/brake-horse-power-hour of NOx, 2) have no more than five percent energy penalty, and 3) cost no more than ten percent of the engine cost. These goals were all aimed at heavy-duty diesel trucks. This CRADA had its Defense Program funding eliminated by DOE prior to completion in 1995. Prior to loss of funding from DOE, LLNL discovered that due to the large oxygen content in diesel exhaust, direct chemical reduction was not possible. In understanding why, a breakthrough was achieved that combined the use of a non-thermal plasma and a catalyst. This process was named Plasma Assisted Catalytic Reduction (P ACR). Because of this breakthrough, the CRADA became a funds-in only CRADA, once DOE DP funding ended. As a result, the funding decreased from about 1M dollars per year to about $400k per year. Subsequently, progress slowed as well. The CRADA was amended several times to reflect the funds-in nature. At each amendment, the deliverables were modified; the goals remained the same but the focus changed from heavy-duty to lightduty to SUVs. The diesel-engine NOx problem is similar to the furnace and boiler NOx emission problem with the added constraint that ammonia-like additives are impractical for a mobile source. Lean-burning gasoline engines are an additional area of application because the standard three-way catalyst is rendered ineffective by the presence of oxygen. In the P ACR process an electrical discharge is used to create a non-thermal plasma that contains oxidative radicals O and OH. These oxidative radicals convert NO to NO2. Selective catalytic reduction using a readily available catalyst then converts the NO2 to harmless gases, N2 and 02.
- Research Organization:
- Lawrence Livermore National Laboratory (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC52-07NA27344
- OSTI ID:
- 1410009
- Report Number(s):
- LLNL-TR-741585; UCRL-ID-144523
- Country of Publication:
- United States
- Language:
- English
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