Patent application number | Description | Published |
20100034717 | VANADIUM-FREE CATALYST FOR SELECTIVE CATALYTIC REDUCTION AND PROCESS FOR IT'S PREPARATION - Selective catalytic reduction with ammonia or a compound that decomposes to ammonia is a known method for the removal of nitrogen oxides from the exhaust gas of primarily lean-burn internal combustion engines. The vanadium-containing SCR catalysts that have long been generally used for this are characterized by a good conversion profile. However, the volatility of vanadium oxide can, at higher exhaust gas temperatures, lead to the emission of toxic vanadium compounds. Zeolite-based SCR catalysts, which are used in particular in discontinuous SCR systems, constitute a very cost-intensive solution for the problem. | 02-11-2010 |
20100058746 | CATALYTIC ACTIVATED DIESEL PARTICLE FILTER WITH AMMONIA TRAP EFFECT - A catalytically active diesel particulate filter with ammonia trap action is presented, which, in addition to an oxidation-active coating ( | 03-11-2010 |
20100092358 | CATALYTICALLY COATED DIESEL PARTICLE FILTER, PROCESS FOR PRODUCING IT AND ITS USE - A diesel particulate filter with an oxidation catalyst comprising platinum and palladium deposited thereon is described. Addition of HC storage components to the oxidation catalyst allows the conversion of hydrocarbons and carbon monoxide to be improved significantly. | 04-15-2010 |
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 |
20100221161 | Device for the Purification of Diesel Exhaust Gases - The invention relates to a special device for the purification of diesel exhaust gases, which device comprises, in the flow direction of the exhaust gas, an oxidation catalyst, a diesel particle filter with catalytically active coating, and, downstream of a device for introducing a reducing agent from an external reducing agent source, an SCR catalyst. The oxidation catalyst and the catalytically active coating of the diesel particle filter contain palladium and platinum. The ratio of the noble metals platinum and palladium in the overall system and on the individual components, oxidation catalyst and catalytically coated diesel particle filter, are coordinated with one another in such a way as to obtain firstly an optimum NO/NO | 09-02-2010 |
20100319332 | METHOD FOR THE COATING OF A DIESEL PARTICLE FILTER AND DIESEL PARTICLE FILTER PRODUCED THEREBY - To equip a diesel particle filter with a zeolite-containing coating uniformly over the entire length of the particle filter and with a further zeolite-free coating which is applied, from the entry side of the filter, solely up to a specific length of the filter, it is proposed, first, to apply the zeolite-free coating from the entry side of the filter and only thereafter to apply the zeolite-containing coating over the entire length of the filter from the exit side of the filter. As a result of this sequence of coatings, a better adhesive strength of the coatings than when both coatings are applied from the entry side is ensured. | 12-23-2010 |
20110056187 | METHOD FOR DECREASING NITROGEN OXIDES IN HYDROCARBON-CONTAINING EXHAUST GASES USING AN SCR CATALYST BASED ON A MOLECULAR SIEVE - The invention relates to a process for treating diesel engine exhaust gases comprising nitrogen oxides (NO | 03-10-2011 |
20110142737 | SELECTIVE CATALYTIC REDUCTION OF NITROGEN OXIDES IN THE EXHAUST GAS OF DIESEL ENGINES - A catalyst and a process for selective catalytic reduction of nitrogen oxides in diesel engine exhaust gases with ammonia or a compound decomposable to ammonia are described. The exhaust gas to be cleaned is passed together with ammonia or a compound decomposable to ammonia over a catalyst which comprises a zeolite or a zeolite-like compound containing 1-10% by weight of copper, based on the total weight of the zeolite or of the zeolite-like compound, and a homogeneous cerium-zirconium mixed oxide and/or a cerium oxide. The zeolite used or the zeolite-like compound used is selected from the group consisting of chabazite, SAPO-34, ALPO-34 and zeolite-β. | 06-16-2011 |
20110146237 | EXHAUST GAS PURIFICATION SYSTEM FOR THE TREATMENT OF ENGINE EXHAUST GASES BY MEANS OF SCR CATALYST - An exhaust gas purification system (method and device) for the treatment of diesel exhaust gases containing nitrogen oxides and hydrocarbons is disclosed, which comprises the addition of ammonia or of a compound decomposable to ammonia into the exhaust gas stream and the subsequent leading of the exhaust gas stream over two successively arranged SCR catalysts with different properties and compositions. Both SCR catalysts are free of vanadium compounds and only the downstream SCR catalyst contains zeolite compounds. The exhaust gas purification system according to the invention is characterized by good “kick-off” behavior at low temperatures and a simultaneously high conversion performance over a wide temperature range. | 06-23-2011 |
20110229392 | OXIDATION CATALYST FOR COMMERCIAL VEHICLES COMPRISING A DIESEL MOTOR - An oxidation catalyst is described for the exhaust gas purification of utility vehicles with diesel engines, which contains a substrate and a catalytically active coating of platinum, active aluminium oxide and aluminium-silicon mixed oxide. The two oxidic support materials, aluminium oxide and aluminium-silicon mixed oxide, are catalytically activated with platinum, the majority of platinum being present on the active aluminium oxide. The oxidation catalyst is distinguished by good NO oxidation rates together with a high poisoning resistance against sulfur compounds. | 09-22-2011 |
20120014842 | DIESEL PARTICLE FILTER WITH IMPROVED BACK PRESSURE CHARACTERISTICS - Proposed is a diesel particle filter which comprises a ceramic wall-flow filter substrate and a coating applied in the inflow ducts, which coating is composed of material with a high melting point. The coating ( | 01-19-2012 |
20130121902 | NOVEL MIXED OXIDE MATERIALS FOR THE SELECTIVE CATALYTIC REDUCTION OF NITROGEN OXIDES IN EXHAUST GASES - The invention relates to the use of mixed oxides made of cerium oxide, zirconium oxide, rare earth sesquioxide and niobium oxide as catalytically active materials for the selective catalytic reduction of nitrogen oxides with ammonia or a compound that can decompose to form ammonia in the exhaust gas of internal combustion engines in motor vehicles that are predominantly leanly operated, and to compositions or catalysts which contain said mixed oxides in combination with zeolite compounds and/or zeolite-like compounds and are suitable for the denitrogenation of lean motor vehicle exhaust gases in all essential operating states. | 05-16-2013 |
20130202509 | DIESEL OXIDATION CATALYST - The present invention relates to a catalytically active material consisting of an inner core ( | 08-08-2013 |
20130266497 | COPPER/CHABAZITE-BASED CATALYST WITH IMPROVED CATALYTIC ACTIVITY FOR REDUCTION OF NITROGEN OXIDES - The present invention relates to a process for improving the catalytic activity of a copper-promoted zeolitic catalyst with chabazite structure, to a copper-promoted zeolitic catalyst with chabazite structure and to a process for reducing nitrogen oxides in an offgas stream. | 10-10-2013 |
20130336863 | SCR CATALYTIC CONVERTER HAVING IMPROVED HYDROCARBON RESISTANCE - A catalyst for the selective catalytic reduction of nitrogen oxides in diesel engine exhaust gases using ammonia or a precursor compound decomposable to ammonia is described. The catalyst comprises two superposed coatings applied to a support body, of which the first coating applied directly to the support body comprises a transition metal-exchanged zeolite and/or a transition metal-exchanged zeolite-like compound, and effectively catalyzes the SCR reaction. The second coating has been applied to the first coating so as to cover it on the exhaust gas side. It is configured so as to prevent the contact of hydrocarbons having at least three carbon atoms present in the exhaust gas with the layer beneath, without blocking the passage of nitrogen oxides and ammonia to the first coating. The second coating may be formed from small-pore zeolites and/or small-pore zeolite-like compounds, and from suitable oxides, especially silicon dioxide, germanium dioxide, aluminum oxide, titanium dioxide, tin oxide, cerium oxide, zirconium dioxide and mixtures thereof. As well as the catalyst, routes for production thereof are described. | 12-19-2013 |
20130336866 | CATALYTICALLY ACTIVE MATERIAL AND CATALYTIC CONVERTER FOR THE SELECTIVE CATALYTIC REDUCTION OF NITROGEN OXIDES - The invention relates to a catalytically active material for reacting nitrogen oxides with ammonia in the presence of hydrocarbons. The material consists of an inner core ( | 12-19-2013 |