Patent application number | Description | Published |
20090129995 | Method for coating a surface filter with a finely divided solids, filter so obtained and its use - Coating a wall-flow filter with a catalytically active coating generally increases the exhaust-gas backpressure in the filter. The increase in the exhaust-gas backpressure is particularly pronounced if a slurry of fine-particle catalyst materials is used for the coating operation. The increase in the exhaust-gas backpressure can be restricted to a tolerable level if, prior to the coating operation, the slurry is so finely milled that virtually the entire mass of the catalyst materials is introduced into the pores of the filter and deposited on the inner surfaces of the pores. This is the case if the d | 05-21-2009 |
20090305874 | METHOD FOR CATALYTICALLY COATING CERAMIC HONEYCOMB BODIES - The invention relates to a process for coating ceramic honeycomb bodies with a coating suspension containing, in a carrier liquid, catalyst components as solids and/or in dissolved form. The honeycomb bodies have parallel flow channels running through them. The walls of the flow channels generally have an open pore structure. To coat the channel walls and in particular also the interior surfaces of the pores with the coating suspension, it is proposed that the flow channels be temporarily alternately closed and the coating suspension be forced through the open pore structure of the channel walls. The coating is subsequently dried and calcined. To close the flow channels, it is possible to use thermally or chemically decomposable or soluble compositions which are decomposed or dissolved either during calcination or by means of a subsequent chemical treatment. The coated honeycomb bodies are preferably used for the purification of exhaust gases from automobiles. | 12-10-2009 |
20100095658 | CATALYST SYSTEM AND USE THEREOF - Soot filters for removing soot from the exhaust gas of lean-burn engines become blocked with progressive operating duration on account of the deposition of soot, and must therefore be regenerated at regular intervals. It has been found that reliable operation of the soot filter is possible only if an active regeneration is carried out from time to time by increasing the exhaust-gas temperature to the soot ignition temperature. For this purpose, an oxidation catalytic converter is usually arranged upstream of the soot filter, and the exhaust-gas temperature is increased by means of the catalytic combustion of additionally injected fuel. Here, the oxidation catalytic converter is subjected to high temperature loading and therefore ages very quickly. It has surprisingly been found that the ageing of the oxidation catalytic converter can be slowed if said oxidation catalytic converter is split into at least two separate catalytic converters and the distance between said separate catalytic converters is 2 to 30 mm. | 04-22-2010 |
20110173951 | METHOD AND DEVICE FOR THE PURIFICATION OF DIESEL EXHAUST GASES - The invention proposes a method for the purification of exhaust gases which are generated by a diesel engine with a charging turbine, and a special device for carrying out said method. The device comprises, in the flow direction of the exhaust gas, a dosing device for a reducing agent from a reducing agent reservoir ( | 07-21-2011 |
20120321842 | Catalytically Coated Ceramic Honeycomb Bodies - The invention relates to a process for coating ceramic honeycomb bodies with a coating suspension containing, in a carrier liquid, catalyst components as solids and/or in dissolved form. The honeycomb bodies have parallel flow channels running through them. The walls of the flow channels generally have an open pore structure. To coat the channel walls and in particular also the interior surfaces of the pores with the coating suspension, it is proposed that the flow channels be temporarily alternately closed and the coating suspension be forced through the open pore structure of the channel walls. The coating is subsequently dried and calcined. To close the flow channels, it is possible to use thermally or chemically decomposable or soluble compositions which are decomposed or dissolved either during calcination or by means of a subsequent chemical treatment. The coated honeycomb bodies are preferably used for the purification of exhaust gases from automobiles. | 12-20-2012 |
20130156668 | CATALYST FOR REMOVING NITROGEN OXIDES FROM THE EXHAUST GAS OF DIESEL ENGINES - The invention relates to a catalyst for removal of nitrogen oxides from the exhaust gas of diesel engines, and to a process for reducing the level of nitrogen oxides in the exhaust gas of diesel engines. The catalyst consists of a support body of length L and of a catalytically active coating which in turn may be formed from one or more material zones. The material zones comprise a copper-containing zeolite or a zeolite-like compound. The materials used include chabazite, SAPO-34, ALPO-34 and zeolite β. In addition, the material zones comprise at least one compound selected from the group consisting of barium oxide, barium hydroxide, barium carbonate, strontium oxide, strontium hydroxide, strontium carbonate, praseodymium oxide, lanthanum oxide, magnesium oxide, magnesium/aluminum mixed oxide, alkali metal oxide, alkali metal hydroxide, alkali metal carbonate and mixtures thereof. Noble metal may optionally also be present in the catalyst. | 06-20-2013 |
20130189172 | CATALYST FOR REMOVING NITROGEN OXIDES FROM THE EXHAUST GAS OF DIESEL ENGINES - The invention relates to a catalyst for removal of nitrogen oxides from the exhaust gas of diesel engines, and to a process for reducing the level of nitrogen oxides in the exhaust gas of diesel engines. The catalyst consists of a support body of length L and of a catalytically active coating which in turn may be formed from one or more material zones. The material zones comprise selectively catalytically reductive (SCR-active) mixed oxide consisting of cerium oxide, zirconium oxide, rare earth sesquioxide and niobium oxide and optionally tungsten oxide. In addition, the material zones comprise at least one compound selected from the group consisting of barium oxide, barium hydroxide, barium carbonate, strontium oxide, strontium hydroxide, strontium carbonate, praseodymium oxide, lanthanum oxide, magnesium oxide, mixed magnesium/aluminum oxide, alkali metal oxide, alkali metal hydroxide, alkali metal carbonate and mixtures thereof. Noble metal may optionally also be present in the catalyst. | 07-25-2013 |
20140041366 | CATALYTIC CONVERTER FOR THE SELECTIVE CATALYTIC REDUCTION OF NITROGEN OXIDES IN THE EXHAUST GAS OF DIESEL ENGINES - The present invention relates to a catalytic converter which comprises a molecular sieve and a mixed oxide, and to a method for the selective catalytic reduction of nitrogen oxides in exhaust gases of diesel engines. | 02-13-2014 |