Examination of Conversion of C3H8 into C3H6 by Electric Discharge Plasma Treatment for Lean-Burn Engines 2007-01-1243
The conversion of fuel into C2H4 and C3H6 by an electric discharge plasma treatment is studied in this work. C2H4 and C3H6 are used as an active species for NOx reduction in an automobile catalyst. They are also useful in the electric discharge plasma reactor of lean-burn engines as plasma assist gas. We suggest a discharge plasma converter (DPC) on the previous catalyst or the second discharge plasma reactor. DPC works as a plasma assist gas converter. Plasma assist gas is generated with discharge plasma treatment at high temperature from fuel or an ingredient of exhaust gas. Diesel fuel, gasoline (C5H12) or Liquefied petroleum gas (C3H8) are enable to use as the fuel. The ingredient of exhaust gas includes C5H12 in the case of gasoline lean-burn engines. DPC consists of a needle electrode and a metal tube. Electric discharge plasma is generated between the needle and the inner wall of the metal tube. The conversion of C3H8 and C5H12 as volatile reagents has been investigated. C3H8 or C5H12 was diluted by air consisting of 90% nitrogen, 10% oxygen, and approximately 10,000 ppm water; C3H8 and C5H12 were 350 and 210 ppm, respectively. Discharge plasma was generated in the DPC and maintained at 600°C. C3H8 was oxidized by the discharge plasma and converted into C3H6 and C2H4. The concentration of products (C2H4 and C3H6) was 143 ppm with specific energy density 5J/L. The ratio of products/reagent was 40%. Without discharge plasma the concentration of these products was 101 ppm. In the case of C5H12 the concentration of these products was 65 ppm with 5J/L. The ratio of products/reagent was 31%. The concentration of these products was 56 ppm without discharge plasma.