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Title: Plasma-assisted catalytic storage reduction system

Abstract

A two-stage method for NO.sub.x reduction in an oxygen-rich engine exhaust comprises a plasma oxidative stage and a storage reduction stage. The first stage employs a non-thermal plasma treatment of NO.sub.x gases in an oxygen-rich exhaust and is intended to convert NO to NO.sub.2 in the presence of O.sub.2 and hydrocarbons. The second stage employs a lean NO.sub.x trap to convert such NO.sub.2 to environmentally benign gases that include N.sub.2, CO.sub.2, and H.sub.2 O. By preconverting NO to NO.sub.2 in the first stage with a plasma, the efficiency of the second stage for NO.sub.x reduction is enhanced. For example, an internal combustion engine exhaust is connected by a pipe to a first chamber in which a non-thermal plasma converts NO to NO.sub.2 in the presence of O.sub.2 and hydrocarbons, such as propene. A flow of such hydrocarbons (C.sub.x H.sub.y) is input from usually a second pipe into at least a portion of the first chamber. The NO.sub.2 from the plasma treatment proceeds to a storage reduction catalyst (lean NO.sub.x trap) that converts NO.sub.2 to N.sub.2, CO.sub.2, and H.sub.2 O, and includes a nitrate-forming catalytic site. The hydrocarbons and NO.sub.x are simultaneously reduced while passing through the lean-NO.sub.x trap catalyst. Themore » method allows for enhanced NO.sub.x reduction in vehicular engine exhausts, particularly those having relatively high sulfur contents.« less

Inventors:
 [1];  [2];  [3];  [3]
  1. (San Ramon, CA)
  2. (Fremont, CA)
  3. (Livermore, CA)
Issue Date:
Research Org.:
Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
OSTI Identifier:
872920
Patent Number(s):
6038853
Assignee:
Regents of University of California (Oakland, CA) LLNL
DOE Contract Number:  
W-7405-ENG-48
Resource Type:
Patent
Country of Publication:
United States
Language:
English
Subject:
plasma-assisted; catalytic; storage; reduction; two-stage; method; oxygen-rich; engine; exhaust; comprises; plasma; oxidative; stage; employs; non-thermal; treatment; gases; intended; convert; presence; hydrocarbons; lean; trap; environmentally; benign; preconverting; efficiency; enhanced; example; internal; combustion; connected; pipe; chamber; converts; propene; flow; input; portion; proceeds; catalyst; nitrate-forming; site; simultaneously; reduced; passing; lean-no; allows; vehicular; exhausts; particularly; relatively; sulfur; contents; environmentally benign; sulfur content; internal combustion; combustion engine; non-thermal plasma; method allows; engine exhaust; storage reduction; benign gases; plasma treatment; plasma converts; simultaneously reduced; simultaneously reduce; oxygen-rich exhaust; engine exhausts; exhaust comprises; method allow; stage method; plasma-assisted catalytic; /60/422/423/

Citation Formats

Penetrante, Bernardino M., Vogtlin, George E., Merritt, Bernard T., and Brusasco, Raymond M. Plasma-assisted catalytic storage reduction system. United States: N. p., 2000. Web.
Penetrante, Bernardino M., Vogtlin, George E., Merritt, Bernard T., & Brusasco, Raymond M. Plasma-assisted catalytic storage reduction system. United States.
Penetrante, Bernardino M., Vogtlin, George E., Merritt, Bernard T., and Brusasco, Raymond M. Sat . "Plasma-assisted catalytic storage reduction system". United States. https://www.osti.gov/servlets/purl/872920.
@article{osti_872920,
title = {Plasma-assisted catalytic storage reduction system},
author = {Penetrante, Bernardino M. and Vogtlin, George E. and Merritt, Bernard T. and Brusasco, Raymond M.},
abstractNote = {A two-stage method for NO.sub.x reduction in an oxygen-rich engine exhaust comprises a plasma oxidative stage and a storage reduction stage. The first stage employs a non-thermal plasma treatment of NO.sub.x gases in an oxygen-rich exhaust and is intended to convert NO to NO.sub.2 in the presence of O.sub.2 and hydrocarbons. The second stage employs a lean NO.sub.x trap to convert such NO.sub.2 to environmentally benign gases that include N.sub.2, CO.sub.2, and H.sub.2 O. By preconverting NO to NO.sub.2 in the first stage with a plasma, the efficiency of the second stage for NO.sub.x reduction is enhanced. For example, an internal combustion engine exhaust is connected by a pipe to a first chamber in which a non-thermal plasma converts NO to NO.sub.2 in the presence of O.sub.2 and hydrocarbons, such as propene. A flow of such hydrocarbons (C.sub.x H.sub.y) is input from usually a second pipe into at least a portion of the first chamber. The NO.sub.2 from the plasma treatment proceeds to a storage reduction catalyst (lean NO.sub.x trap) that converts NO.sub.2 to N.sub.2, CO.sub.2, and H.sub.2 O, and includes a nitrate-forming catalytic site. The hydrocarbons and NO.sub.x are simultaneously reduced while passing through the lean-NO.sub.x trap catalyst. The method allows for enhanced NO.sub.x reduction in vehicular engine exhausts, particularly those having relatively high sulfur contents.},
doi = {},
journal = {},
number = ,
volume = ,
place = {United States},
year = {2000},
month = {1}
}

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