Plasma regenerated particulate trap and NOx reduction system

• Main Authors: VOGTLIN; GEORGE E, MERRITT; BERNARD T, PENETRANTE; BERNARDINO M, BRUSASCO; RAYMOND M
• Format: Patent
• Language: English
• Published: 21.03.2000
• Edition: 7
• Subjects: BLASTING; CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TOTRANSPORTATION; ENGINE PLANTS IN GENERAL; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR INTERNALCOMBUSTION ENGINES; GAS-FLOW SILENCERS OR EXHAUST APPARATUS FOR MACHINES ORENGINES IN GENERAL; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; HEATING; LIGHTING; MACHINES OR ENGINES IN GENERAL; MECHANICAL ENGINEERING; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; STEAM ENGINES; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS; TECHNOLOGIES FOR ADAPTATION TO CLIMATE CHANGE; TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINSTCLIMATE CHANGE; TRANSPORTING; WEAPONS

A non-catalytic two-stage process for removal of NOx and particulates from engine exhaust comprises a first stage that plasma converts NO to NO2 in the presence of O2 and hydrocarbons, and a second stage, which preferably occurs simultaneously with the first stage, that converts NO2 and carbon soot particles to respective environmentally benign gases that include N2 and CO2. By preconverting NO to NO2 in the first stage, the efficiency of the second stage for NOx reduction is enhanced while carbon soot from trapped particulates is simultaneously converted to CO2 when reacting with the NO2 (that converts to N2). For example, an internal combustion engine exhaust is connected by a pipe to a chamber where carbon-containing particulates are electrostatically trapped or filtered and a non-thermal plasma converts NO to NO2 in the presence of O2 and hydrocarbons. Volatile hydrocarbons (CxHy) from the trapped particulates are oxidized in the plasma and the remaining soot from the particulates reacts with the NO2 to convert NO2 to N2, and the soot to CO2. The nitrogen exhaust components remain in the gas phase throughout the process, with no accompanying adsorption.