摘要:
Provided are selective catalytic reduction catalytic articles, emission treatment systems and methods for simultaneously remediating the nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons present in diesel engine exhaust streams. The catalytic articles have a Selective Catalytic Reduction (SCR) catalyst uniformly coated over the outlet portion of wall flow filter walls resulting in reduction of NO2 and combustion of the soot without substantially increasing the system backpressure.
摘要:
Catalysts and catalytic articles for treating exhaust gas streams are described. In one or more embodiments, a catalyst system includes a first zone to abate nitrogen oxides by selective catalytic reduction, a second zone to oxidize ammonia and a third zone to oxidize carbon monoxide and hydrocarbons. Methods for treating the exhaust gas stream are also provided. Methods of making and using such catalysts and catalytic articles are also described.
摘要:
Catalysts and catalytic articles for treating exhaust gas streams are described. In one or more embodiments, a catalyst system includes a first zone to abate nitrogen oxides by selective catalytic reduction, a second zone to oxidize ammonia and a third zone to oxidize carbon monoxide and hydrocarbons. Methods for treating the exhaust gas stream are also provided. Methods of making and using such catalysts and catalytic articles are also described.
摘要:
Provided are catalyst articles, emission treatment systems and methods for simultaneously remediating the carbon monoxide, nitrogen oxides (NOx), particulate matter, and gaseous hydrocarbons present in diesel engine exhaust streams. The emission treatment system of specific embodiment effectively treats diesel engine exhaust with a single catalyst article.
摘要:
Catalytic articles, methods and emissions treatment systems for treating an engine exhaust gas stream containing NOx and particulate matter are disclosed and include a particulate filter comprising a first SCR catalyst for NOx conversion disposed downstream of the injector. The particulate filter is a partial filter with a particle filtration efficiency between about 30% and 60% and an SCR catalyst loading in the range of 0.1 g/in3-3.5 g/in3.
摘要:
Catalysts, methods of preparing catalyst, and methods for treating exhaust gas streams are described. In one or more embodiments, a catalyst system includes an upstream zone effective to catalyze the conversion of a mixture of NOx and NH3 to N2, and a downstream zone effective for the conversion of ammonia to N2 in the presence or absence of NOx. In an embodiment, a method for preparing a catalyst system includes: first coating one end of a substrate along at least 5% of its length with an undercoat washcoat layer containing a material composition effective to catalyze the removal of ammonia; second coating with an overcoat layer containing a material composition effective to catalyze the conversion of a mixture of NOx and NH3 to N2. A method for treating the exhaust gas stream is provided, which includes injecting ammonia or an ammonia precursor into an exhaust gas stream of a vehicle, passing the engine exhaust gas stream containing NOx and NH3 through the upstream zone of a catalyst system to remove NOx and then passing the exhaust gas stream through the downstream zone of the catalyst system to remove NH3, as well as other oxidizable species such as hydrocarbons and CO.
摘要:
A process for stably operating a continuous preparation process for obtaining acrolein or acrylic acid or a mixture thereof from propane, in which the feed rate of fresh propane to the process is utilized as a correcting element for stable steady-state operation.
摘要:
A process for preparing acrolein or acrylic acid or a mixture thereof from propane, in which propane is dehydrogenated under heterogeneous catalysis in a reaction zone A and the propylene formed is partially oxidized heterogeneously in a reaction zone, reaction zone A being operated in loop mode and reaction gas mixture input stream A fed to the reaction zone A comprising added molecular hydrogen which is added to this input stream as late as possible.
摘要:
A process for preparing at least one target product by partial oxidation and/or ammoxidation of propylene, in which the propylene source used is a propane dehydrogenation, the propane used therein being obtained by a rectificative prepurification of crude propane.
摘要:
A process for removing methacrolein from liquid phase P comprising acrylic acid as a main constituent and target product, and methacrolein as a secondary component in which the removal is effected by crystallization, the acrylic acid accumulating in the crystals formed and the methacrolein in the remaining mother liquor.