Patent · US Active

Hybrid catalyst for NOx reduction using fuel hydrocarbons as reductant

US7891171B2 · kind B2 · utility

6Cited by
11References
38Claims
0Family size

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Inventors

Key dates

Filing dateDec 5, 2006
Grant dateFeb 22, 2011
Priority date
Expiry dateFeb 24, 2029

Classification

  • Technology area (CPC Y)Emerging Cross-Sectional Technologies
  • CPC primaryY02A50/20
  • WIPO fieldChemical engineering
  • WIPO sectorChemistry

Abstract

A method for reducing nitrogen oxides including NO and NO2 in an exhaust stream also comprising oxygen, carbon monoxide and hydrocarbons at a temperature above about 150° C., the method including in embodiments oxidizing NO in the exhaust stream to NO2; reforming raw diesel fuel to produce OHC's from the fuel; adding diesel fuel hydrocarbons and their oxygenates to the exhaust stream for the reduction of nitrogen oxides; and contacting the exhaust stream with a reduction hybrid catalyst comprising BaY—Ag/Al2O3 to reduce the nitrogen oxides to N2. The method reduces NOx initially through the (HC+OHC)/SCR process producing N2, while also producing NH3 as a byproduct over Ag/Al2O3. The NH3 subsequently reduces NOx over the BaY—Ag/Al2O3 hybrid catalyst through the NH3/SCR process, producing more N2 and thereby enhancing the NOx reduction efficiency of the hybrid catalyst system.

Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.