| 摘要 |
#CMT# #/CMT# Treating a gas mixture containing 50-2500 ppm methane and 0.5-12 vol.% oxygen to convert the methane to carbon monoxide comprises feeding the mixture at 200-500[deg] C into a plasma reactor having an external electrode and an internal electrode and applying a high voltage across the electrodes to generate a plasma with an energy density of 15-100 J/L. #CMT#USE : #/CMT# The treatment is useful for removing unburned methane from exhaust gases, e.g. from boilers or engines, especially homogeneous charge compression ignition (HCCI) engines or gas engines. #CMT#CHEMICAL ENGINEERING : #/CMT# Preferred Process: The gas mixture is derived from the combustion of natural gas or a liquid fuel or from a fixed or mobile combustion source, especially an engine or boiler. One of the electrodes is covered with a dielectric material to create a dielectric barrier discharge. The mixture leaving the plasma reactor is contacted with a catalyst to convert residual methane to carbon dioxide. The catalyst comprises 0.1-1 wt.% platinum and/or 0.1-2 wt.% palladium on alumina or silica. #CMT#EXAMPLE : #/CMT# Exhaust gas containing containing 1000 ppm methane, 150 ppm nitric oxide, 7 vol.% oxygen and 8 vol.% carbon dioxide was treated at 450[deg] C in a plasma reactor operated at various energy densities. Methane conversion at energy densities of 15, 36, 58, 80 and 100 J/L was 18, 39, 50, 63 and 75% respectively. |
