A Study on the Improvement of NOx Reduction Efficiency for a Urea SCR System (Eighth Report)

尿素SCR システムのNOx 浄化率向上に関する研究(第8報)

The urea SCR system is a major diesel NOx aftertreatment system. An ammonia slip catalyst (ASC) is located downstream of the SCR system to remove ammonia slipping from it, resulting in forming N₂O having a significantly high global warming potential. Thus, the authors adopted dual-layered ASCs to identify how N₂O is formed in the oxidation layer and how Zeolite layer thickness effects NH₃ to N₂O conversion characteristics. Engine tests and numerical simulations were conducted. The results show that Zeolite has a supplemental effect of reducing NOx and that an reduction in N₂O formation is possible by increasing zeolite layer thickness while NH₃ conversion is decreased. Thus, it is confirmed that zeolite layer thickness should be optimized to reduce these two emissions.ディーゼル機関のNOxを浄化する尿素SCRシステムでは,スリップしたNH₃の酸化触媒(ASC)におけるN₂Oの生成が問題とされている.そこで本研究では,Dual-layerのASCを採用し,Zeolite層の厚みがN₂Oの生成とNH₃浄化に及ぼす影響について実験と数値計算を行い,その層厚さの増加に従ってN₂Oの生成割合が減少する効果を確認した.


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  • Accession Number: 01674292
  • Record Type: Publication
  • Source Agency: Japan Science and Technology Agency (JST)
  • Files: TRIS, JSTAGE
  • Created Date: Jan 31 2018 3:21PM