摘要:
Vorrichtung (1) zum Zumischen eines Reduktionsmittels (5) in einen Abgasstrom einer Brennkraftmaschine mit einem Abgasstrang (2) und mit einer Dosiervorrichtung (3) zur Zuführung des Reduktionsmittels (5) in den Abgasstrang (2), wobei die Dosiervorrichtung (3) in oder an einem an den Abgasstrang (2) angeordneten Hohlkörper (4) angeordnet ist, dessen Innenvolumen abgasführend mit dem Abgasstrang (2) verbunden ist und wobei das Reduktionsmittel (5) in den Hohlkörper (4) emdüsbar ist, wobei zwischen dem Hohlkörper (4) und dem eingedüsten Reduktionsmittel (5) ein Mantelkörper (6) vorgesehen ist, der das Reduktionsmittel (5) zumindest bereichsweise im Innenvolumen umhüllt. Durch die erfindungsgemäße Ausgestaltung wird eine Ablagerung von Reduktionsmittel an der Dosiervorrichtung und an dem Hohlkörper vermieden.
摘要:
It is the aim of the present invention to provide a method and a system for the treatment of a NO x - and soot-containing exhaust gas stemming from an internal combustion engine that combines soot filtration/deposition and selective catalytic reduction of NO x in a new way to foster the overall system efficiency and to reduce system size and weight. This aim is achieved according to the present invention by a method and a system for a treatment of a NO x - and soot- containing exhaust gas stemming from an internal combustion engine (4); comprising the steps of : a) providing NO2 in the NO x - and soot-containing exhaust gas by an internal combustion measure and/or by bringing at least a part of the NO x - and soot-containing exhaust gas into contact with an oxidation catalyst (6); b) injecting at least into a part of the NO x - and soot- containing exhaust gas a predetermined amount of ammonia, either as neat ammonia or as a precursor compound for ammonia, such as urea, a liquid solution of urea, ammonium carbamate, isocyanic acid, cyanuric acid, methanamide, etc. or combinations of them, downstream and/or parallel to the controlling of the amount of the NO 2 as seen in the flow direction of the NO x - and soot-containing exhaust gas; c) bringing the ammonia-enriched NO x - and soot-containing exhaust gas into contact with a support structure (16) filtering and thereby depositing soot particles (14) from the NO x - and soot-containing exhaust gas on its surface thereby initiating a selective catalytic reduction of at least a part of the N0 x -molecules with ammonia to nitrogen and water.
摘要:
A composite wood product is manufactured by heating and pressing wood materials in contact with a mixture of resin and urea. Gases that evolve from the heating and pressing of the wood materials, resin and urea are collected and are passed through a biological oxidation system to remove volatile organic compounds.
摘要:
Embodiments of the invention pertain to a catalyst, which may be used in a catalytic converter for treating a gas stream containing pollutants. In an embodiment, the catalyst comprises a substrate having a plurality of axially enclosed channels defined by the porous wall elements extending between an inlet end and an outlet end. Washcoat particles are disposed substantially within the pores of the walls, and the surfaces of the wall elements have a porous, rough texture after coating with the washcoat and substantially no fillets formed on the channels.
摘要:
Es wird ein Verfahren zur selektiven katalytischen Reduktion von Stickoxiden mit Ammoniak in Abgasen von Fahrzeugen beschrieben, wobei man Lösungen von Guanidinsalzen mit einem Ammoniak-Bildungspotential von 40 bis 850 g/kg ggf. in Kombination mit Harnstoff und/oder Ammoniak und/oder Ammoniumsalzen in Gegenwart von katalytisch aktiven, nicht oxidationsaktiven Beschichtungen aus Oxiden, ausgewählt aus der Gruppe Titandioxid, Aluminiumoxid, Siliciumdioxid bzw. deren Mischungen sowie hydrothermal stabilen Zeolithen, die vollständig oder teilweise metallausgetauscht sind, katalytisch zersetzt. Mit Hilfe der erfindungsgemäβ vorgeschlagenen Guanidinsalze ist es möglich, eine Reduktion der Stickoxide um ca. 90 % zu erzielen. Auβerdem kann mit diesen Guanidinsalzen eine Erhöhung des Ammoniak-Bildungspotentials von 0,2 kg entsprechend dem Stand der Technik bis auf 0,4 kg Ammoniak pro Liter Guanidinsalz bei gleichzeitiger Winterfestigkeit (Gefrierpunkt unter -25°C) erreicht werden. Schlieβlich ist auch die Korrosionsgefahr der erfindungsgemäβ eingesetzten Guanidinsalz-Lösungen im Vergleich zu Lösungen mit Ammoniumformiat deutlich verringert.
摘要:
Improvements are described in the injection of ammonia (NH3) into the exhaust gases of an engine to reduce nitrogen oxides. Instead of merely injecting ammonia into the exhaust gas conduit through a hole in its side, an ammonia injector (90) is provided that projects considerably into the exhaust conduit (16), with the injector having a plurality of holes (94). The ammonia is activated to decompose it into its reactive components, including NH2 and NH prior to injecting it into the exhaust conduit. Such activation prior to injection can be accomplished by heating the ammonia in the presence of a catalyst such as a metal of the platinum group, iron, nickel, or zinc. In an engine that has a fuel injection system wherein electrical pulses are delivered to fuel injectors to control the fuel flow rate, the durations of these electrical signals are used to control the opening of a valve (72) that controls the flow rate of ammonia into the exhaust gas conduit.
摘要:
The invention pertains to an integrated process for capturing CO 2 . The process involves desorbing gaseous CO 2 from a CO 2 containing aqueous solution comprising carbonate, bicarbonate, sesquicarbonate, carbamate, or a mixture thereof. The desorbing of gaseous CO 2 is conducted in the presence of a suitable water soluble substance. If desired, the process may also at least partially recover the soluble substance using a membrane, distillation, or another technique.
摘要:
Processes and systems (10,110) for producing potassium sulfate (36) as a byproduct of a desulfurization process. Sulfur dioxide is absorbed (12) from a flue gas (14) using an ammonia-containing solution to produce an ammonium sulfate solution (24) that contains dissolved ammonium sulfate. At least a first portion (25) of the ammonium sulfate solution (24) is heated (26) before dissolving potassium chloride (22) therein to form a slurry (28) that contains potassium sulfate crystals (36) and an ammonium chloride solution. The slurry (28) is then cooled (32) to precipitate additional potassium sulfate crystals (36), after which the potassium sulfate crystals (36) are removed (34) to yield a residual ammonium chloride solution (38,48) that contains dissolved ammonium chloride and residual dissolved potassium sulfate. Ammonia (50) is then absorbed (40) into the residual ammonium chloride solution (38) to further precipitate potassium sulfate crystals (42), which are removed (44) to yield a residual ammonium chloride solution (46) that is substantially free of dissolved potassium sulfate.
摘要:
Reactive composition comprising between 60 % and 98 % by weight of sodium bicarbonate, between 1 % and 40 % by weight of sodium carbonate and between 0.02 % and 2.0 % by weight of ammonia, expressed in the form of ammonium ions NH 4 + , characterized in that the composition comprises less than 1.0 % by weight of water.