A plugged honeycomb structure including: a pillar-shaped honeycomb structure body having porous partition walls made of a material including silicon carbide, and plugging portions, wherein a porosity of the partition walls is from 42 to 52%, a thickness of the partition walls is from 0.15 to 0.36 mm, a ratio of a volume of pores having pore diameters of 10 m or less to a total pore volume of the partition walls is 41% or less, a ratio of a volume of pores having pore diameters in a range of 18 to 36 m to the total pore volume is 10% or less, the pore diameter indicating a maximum value of the log differential pore volume is in a range of 10 to 16 m, and a half-value width of a peak including the maximum value of the log differential pore volume is 5 m or less.

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.

The present invention relates to the technical field of catalyst preparation, disclosing a preparation method and application of a coated vanadium-tungsten-titanium oxide monolithic SCR catalyst. The method includes the steps of mixing a vanadium oxide precursor, a tungsten oxide precursor, titanium dioxide, an inorganic adhesive, an organic adhesive and a macromolecular surfactant with deionized water and stirring them to obtain a thick liquid; adding a pH adjuster to the thick liquid to make its pH 1.5-4.5; impregnating a cordierite honeycomb carrier in the thick liquid to obtain a preliminarily-impregnated catalyst and dried and calcined the preliminarily-impregnated catalyst to obtain a finished catalyst. The method has advantages such as simple operation, easy repetition and short time-consuming, so it can be applied to exhaust gas post-treatment of a marine diesel engine, and provide a good choice for catalysts used to denitrify medium and high temperature exhausted gas from marine engines.

The invention relates to a method for separating mercury (Hg) from furnace gases of combustion plants, wherein a catalytically active material having a mean grain diameter <35 ?m is metered into the furnace gas, the elemental mercury in the furnace gases is oxidized, and resulting oxidized mercury is separated in the process using adsorption and absorption techniques in preexisting plant technology. The intensified formation of oxidized mercury is performed within a temperature range <500? C.

A SCR catalyst for removing nitrogen oxides comprises: a carrier prepared from a support in which Ti-PILC is mixed with titania; and a catalyst material on the carrier, wherein the catalyst material contains an active material of a vanadium component and a co-catalyst of a tungsten component. On the basis of the total weight of the catalyst, the support Ti-PILC is contained at 0.01-40 wt %, and the support titania is contained at 50 to 90 wt %. In addition, a method for producing a SCR catalyst for removing nitrogen oxides comprises the steps of: preparing a carrier by using a support in which Ti-PILC is mixed with titania; and supporting a catalyst material on the carrier. The present disclosure provides: a SCR catalyst for removing nitrogen oxides, which has an excellent nitrogen oxide removing performance and a high producing convenience; and a method for producing the same.

The disclosure concerns an improved method of preparation of nanoparticular vanadium oxide/anatase titania catalysts having a narrow particle size distribution. In particular, the disclosure concerns preparation of nanoparticular vanadium oxide/anatase titania catalyst precursors comprising combustible crystallization seeds upon which the catalyst metal oxide is coprecipitated with the carrier metal oxide, which crystallization seeds are removed by combustion in a final calcining step.

The invention relates to a catalyst comprising at least two catalytically active layers, A and B, wherein A contains a carrier oxide and components A1 and A2, and B contains a carrier oxide and components B1, B2, and B3, wherein A1, A2, and B1 to B3 are defined as disclosed in claim 1. The proportion of component A1 in layer A is thereby greater than the proportion of component B1 in layer B, wherein the proportion of layer A with respect to the total weight of layers A and B, is greater than the proportion of layer B. The invention further relates to a method for reducing nitrogen oxides in exhaust gases of lean-burn internal combustion engines and to an exhaust gas cleaning system.

An aftertreatment system includes a first oxidation catalyst, a second oxidation catalyst, and a turbocharger. The first oxidation catalyst is upstream of the turbocharger and includes a first oxidation catalyst formulation. The second oxidation catalyst is downstream of the turbocharger and includes a second oxidation catalyst formulation different than the first oxidation catalyst formulation. The second oxidation catalyst formulation is configured to promote conversion of nitric oxide (NO) to nitrogen dioxide (NO.sub.2).

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.

Three way catalyst having an NH.sub.3-SCR activity, an ammonia oxidation activity and an adsorption capacity for volatile vanadium and tungsten compounds volatilized off an upstream SCR active catalyst.