Abstract: The invention provides a process for reducing the amounts of carbon monoxide, hydrocarbons and soot particles in the lean exhaust gas from an internal combustion engine using a particle filter, wherein the soot particles have a soot ignition temperature TZ and the particle filter is regenerated from time to time by raising the temperature of the particle filter to above the soot ignition temperature and burning the soot particles, wherein the temperature of the filter is increased to the temperature required to initiate soot ignition by burning additional fuel on the catalytic coating when the exhaust gas back pressure reaches a predetermined value. The process is characterised in that the particle filter is provided with a catalytic coating comprising a first group of components for reducing the ignition temperature of soot, said first group of components contains at least one oxygen storage component and at least one platinum group metal selected from the group consisting of platinum, palladium and rhodium.

Abstract: A process for reducing the nitrogen oxides present in a lean exhaust gas from an internal combustion engine by selective catalytic reduction on a reduction catalyst using ammonia, wherein a fraction of the nitrogen monoxide present in the exhaust gas is oxidized to nitrogen dioxide before the exhaust gas, together with ammonia, is passed over the reduction catalyst. The reduction catalyst contains a zeolite exchanged with transition metals and oxidation of the nitrogen monoxide is performed in such a way that the exhaust gas contains 30 to 70 vol. % of nitrogen dioxide before contact with the reduction catalyst.

Abstract: A process for reducing the nitrogen oxides present in a lean exhaust gas from an internal combustion engine by selective catalytic reduction on a reduction catalyst using ammonia, wherein a fraction of the nitrogen monoxide present in the exhaust gas is oxidized to nitrogen dioxide before the exhaust gas, together with ammonia, is passed over the reduction catalyst. The reduction catalyst contains a zeolite exchanged with transition metals and oxidation of the nitrogen monoxide is performed in such a way that the exhaust gas contains 30 to 70 vol. % of nitrogen dioxide before contact with the reduction catalyst.

Abstract: A method for removing nitrogen oxides and particulate matter from the lean exhaust gas of a combustion engine that also contains low concentrations of sulfur oxides. The exhaust gas stream is passed over a nitrogen oxide storage catalyst and a particulate filter, where nitrogen oxides and sulfur oxides are adsorbed by the storage catalyst under lean exhaust gas conditions and the particulate matter is deposited on the particulate filter. The storage catalyst is in a first cycle is periodically denitrated by enriching the exhaust gas regeneration of the particulate filter. Desulfurization of the nitrogen oxide storage catalyst is carried out in a second cycle by raising the temperature of the lean exhaust gas to a value at which the particulate matter combustion on the particulate filter is initiated and then the storage catalyst can be desulfurized by enriching the exhaust gas.

Abstract: A process for reducing the nitrogen oxides present in a lean exhaust gas from an internal combustion engine by selective catalytic reduction on a reduction catalyst using ammonia, wherein a fraction of the nitrogen monoxide present in the exhaust gas is oxidized to nitrogen dioxide before the exhaust gas, together with ammonia, is passed over the reduction catalyst. The reduction catalyst contains a zeolite exchanged with transition metals and oxidation of the nitrogen monoxide is performed in such a way that the exhaust gas contains 30 to 70 vol. % of nitrogen dioxide before contact with the reduction catalyst.

Abstract: The invention provides a redox catalyst for the selective reduction of the nitrogen oxides present in exhaust gas from diesel engines using ammonia. The reduction catalyst contains a catalytically active material which is based on the solid acid system TiO2/WO3/MoO3V2O5/SiO2/SO3 and an oxidation catalyst based on the platinum group metals platinum and palladium. The reduction catalyst is present in the form of a cylindrical honeycomb catalyst with an inlet and an outlet end face. The oxidation catalyst is applied to a section of the reduction catalyst adjacent to the outlet end face. The redox catalyst is characterised in that the catalytically active material in the reduction catalyst is used as support material for the platinum group metals in the oxidation catalyst.

Abstract: The invention provides a process for reducing the amounts of carbon monoxide, hydrocarbons and soot particles in the lean exhaust gas from an internal combustion engine using a particle filter, wherein the soot particles have a soot ignition temperature TZ and the particle filter is regenerated from time to time by raising the temperature of the particle filter to above the soot ignition temperature and burning the soot particles, wherein the temperature of the filter is increased to the temperature required to initiate soot ignition by burning additional fuel on the catalytic coating when the exhaust gas back pressure reaches a predetermined value. The process is characterised in that the particle filter is provided with a catalytic coating comprising a first group of components for reducing the ignition temperature of soot, said first group of components contains at least one oxygen storage component and at least one platinum group metal selected from the group consisting of platinum, palladium and rhodium.

Abstract: A process for removing soot from the exhaust gas of a diesel engine by oxidizing the nitrogen monoxide present in the exhaust gas to nitrogen dioxide, separating the soot from the exhaust gas stream and oxidizing the soot using the nitrogen dioxide produced. The process is performed in at least two consecutive process stages and the soot is separated from the exhaust gas stream with an efficiency W between 0.05 and 0.95 in each process stage, wherein each process stage can be assigned a transmission for soot in accordance with T=1−W and the total transmission of the process for soot is given as the product of the transmissions of all the process stages.

Abstract: A process for reducing the nitrogen oxides present in a lean exhaust gas from an internal combustion engine by selective catalytic reduction on a reduction catalyst using ammonia, wherein a fraction of the nitrogen monoxide present in the exhaust gas is oxidized to nitrogen dioxide before the exhaust gas, together with ammonia, is passed over the reduction catalyst. The reduction catalyst contains a zeolite exchanged with transition metals and oxidation of the nitrogen monoxide is performed in such a way that the exhaust gas contains 30 to 70 vol. % of nitrogen dioxide before contact with the reduction catalyst.

Abstract: A method for removing nitrogen oxides and particulate matter from the lean exhaust gas of a combustion engine that also contains low concentrations of sulfur oxides. The exhaust gas stream is passed over a nitrogen oxide storage catalyst and a particulate filter, where nitrogen oxides and sulfur oxides are adsorbed by the storage catalyst under lean exhaust gas conditions and the particulate matter is deposited on the particulate filter. The storage catalyst is in a first cycle is periodically denitrated by enriching the exhaust gas regeneration of the particulate filter. Desulfurization of the nitrogen oxide storage catalyst is carried out in a second cycle by raising the temperature of the lean exhaust gas to a value at which the particulate matter combustion on the particulate filter is initiated and then the storage catalyst can be desulfurized by enriching the exhaust gas.

Abstract: The invention concerns a process for the preparation of a vanadia SCR-catalyst supported on titania. The process is characterized in that the catalyst is prepared by dispersing titania in an ammonium metavanadate (NH4VO3) solution, adjusting the pH of the solution to a value of 7.0-7.1 by NH4OH and HNO3, stirring the resulting suspension for a time sufficient for complete adsorption of the vanadium compound on titania, filtering the suspension and drying and calcining the resulting catalyst compound.

Abstract: Disclosed is a process for the preparation of 1,3-propanediol by the hydrogenation of hydroxypropionaldehyde (HPA) in aqueous solution on a formed carrier catalyst in a solid bed, the concentration of HPA in the solution being from 5 to 100% by weight and hydrogenation being carried out at temperatures of from 30.degree. to 180.degree. C. and hydrogen pressures of from 5 to 300 bar and at a pH of from 2.5 to 6.5. The carrier catalyst is formed principally of titanium oxide on which platinum is applied in a finely divided form in a quantity of from 0.1 to 5.0% by weight, based on the carrier.