System for the removal of noxious compounds and particulate matter from exhaust gas of a compression ignition engine comprising a three way catalyst unit having an NH.sub.3-SCR activity, an ammonia oxidation activity and an adsorption activity of volatile vanadium and tungsten compounds volatilized off an upstream SCR active catalyst.

For the purification of waste gas containing carbon compounds and nitrogen oxides by means of a regenerative post-combustion system, at least two regenerators (A, B, C) filled with heat accumulator bodies (7a, 7b, 7c) and connected by a combustion chamber (10) are provided, wherein the waste gas is alternately heated in a regenerator (A, B, C), the carbon compounds are oxidised in the combustion chamber (10), and, with the addition of a nitrogen-hydrogen compound, the nitrogen oxides are reduced in the combustion chamber (10) thermally and thus not catalytically. Remaining nitrogen oxides are removed by means of a catalytically active heat accumulator layer (6a, 6b, 6c) and the addition of a further nitrogen-hydrogen compound in the regenerator (A, B, C) from which the clean gas exits.

In order to improve the lifetime of an SCR catalyst in the waste gas purification by means of the SCR process of waste gas of a biomass combustion plant, the catalyst comprises a sacrificial component selected from a zeolite and/or a clay mineral, in particular halloysite. During operation, catalyst poisons contained in the waste gas, in particular alkali metals, are absorbed by the sacrificial component so that catalytically active centers of the catalyst are not blocked by the catalyst poisons.

An apparatus comprises a first circuit and a second circuit. The first circuit is structured to determine that a combustion cylinder is operating in a transition period between an exhaust stroke and an intake stroke of the combustion cylinder. The second circuit is structured to provide an injection command during the transition period to a fuel injector associated with the combustion cylinder, the injection command being to inject fuel into a combustion chamber of the combustion cylinder such that at least a portion of the fuel escapes from the combustion chamber through an exhaust port of the combustion cylinder.

This exhaust gas purifying catalyst is provided with a substrate 10 and a catalyst layer 20 formed on a surface of the substrate 10. The catalyst layer 20 contains zeolite particles 22 that support a metal, and a rare earth element-containing compound 24 that contains a rare earth element. The rare earth element-containing compound 24 is added in such an amount that the molar ratio of the rare earth element relative to Si contained in the zeolite 22 is 0.001 to 0.014 in terms of oxides.

Disclosed herein are a filter medium and a bag filter for exhaust gas removal in which dropping off and scattering of a catalyst is suppressed during production and during use. Provided is a filter medium containing a fiber layer and a catalyst layer, the catalyst layer containing a catalyst and fibril fibers as main components. Also provided herein is a bag filter comprising the said filter medium, wherein the filter medium is cylindrical.

A combustion system for ships operated at low cost is provided. A combustion system 1 for ships includes an internal combustion engine 20 that burns fuel, an exhaust line L2 through which exhaust gas flows, the exhaust gas being generated through combustion of the fuel in the internal combustion engine 20, an exhaust heat recovery device 40 that is disposed in the exhaust line L2 and that recovers exhaust heat from the exhaust gas discharged from the internal combustion engine 20, and a denitration device 50 that is disposed in the exhaust line L2 and that removes nitrogen oxide from the exhaust gas using a denitration catalyst. The denitration device 50 is disposed downstream from the exhaust heat recovery device 40 in the exhaust line L2. The denitration catalyst contains 43 wt % or more of vanadium pentoxide and has a BET specific surface area of 30 m.sup.2/g or more.

A system for use in selective catalytic reduction reactor is disclosed. The system may include a catalyst bed and a screen located close to the catalyst bed in a manner so that flow of flue gas to the catalyst bed contacts the screen before it contacts the catalyst bed. The screen may be adapted to support a weight of at least 400 pounds above the catalyst bed so that the weight is not imposed on the catalyst. The screen may have a plurality of holes across its surface in a manner so that the screen is adapted to change the velocity distribution of the flue gas as it flows through the screen.

An aftertreatment system comprises a SCR system including at least one catalyst. A NOx sensor is positioned downstream of the SCR system. A controller is configured to determine an estimated engine NOx amount in the exhaust gas produced by an engine fluidly coupled to the aftertreatment system. The controller interprets an output value indicative of a first amount of oxygen in the exhaust gas downstream of the SCR system. The controller determines an adjusted engine NOx amount in response to the output value. A NOx sensor is positioned downstream of the selective catalytic reduction system and communicatively coupled to the controller. The NOx sensor is structured to provide the output value.

The novel sorbents for capturing acid and greenhouse gases converts red mud into a sorbent material that can be used to remove acid and greenhouse gases, utilizing a series of chemical reactions. The first set of reactions entail sorption of the acid/greenhouse gases and subsequent neutralization by the alkali content of the red mud. The salts generated by the neutralization reactions decompose to release the acid gases which are immediately converted to environmentally benign elemental products (N2, O2, S) by thermo-catalytic reactions. In a different set of reactions, the alkaline earth oxides (CaO and MgO) present in the sorbent capture the acid/greenhouse gases and convert them to nitrate, nitrite, carbonate and sulfite salts. The salts (beside carbonate) decompose to yield the acid gases which are converted to elemental products by thermo-catalytic reactions. The loaded sorbents are thermally regenerated to the oxide forms for re-capturing the gases.