A reducing agent injection device includes a honeycomb structure and a urea spraying device spraying a urea water solution in mist form. A pair of electrode members is formed in the honeycomb structure. The honeycomb structure of the reducing agent injection device, the hydraulic diameter HD, defined as HD=4×S/C, when the area of the cross section of one of the cells in the cross section perpendicular to the cell extending direction is S, and the peripheral length of the cross section of one of the cells is C, is 0.8 to 2.0 mm. Also, the open frontal area OFA of the honeycomb structure in the cross section perpendicular to the cell extending direction is 45 to 80%.

A provision of assemblies and methods for treating an exhaust gas from an internal combustion engine. The treatment method comprises at least two catalyst stages. The exhaust gas is directed to a first stage catalyst. After the first stage catalyst, the exhaust is passed to an inter-catalyst stage comprising an exhaust cooling process and an oxygen enrichment process. Next, the exhaust is passed to a second stage catalyst for reducing carbon monoxide, ammonia and hydrocarbon concentration in the exhaust gas, before exiting via an outlet.

A honeycomb structure is formed of a porous ceramic material and has pores in the structural body, wherein cerium dioxide is present in a state that it is incorporated in the structural body in the ceramic material, and at least a part of cerium dioxide particles is exposed on pore surfaces of the pores. The ceramic material includes cordierite or silicon carbide as a major component, the ratio of the cerium dioxide to the ceramic material is in the range of from 1.0% by mass to 10.0% by mass, and at least a part of catalyst particulates of a platinum group element such as platinum or palladium is loaded by the cerium dioxide particles.

A honeycomb structure has partition walls defining a plurality of polygonal cells which become through channels for a fluid, a structure end face vertical to an axial direction has at least two cell regions possessing mutually different cell structures and surrounded by circumferential portions, and in the cell regions adjacent to each other, to first partition walls of a first cell structure of one first cell region, second partition walls of a second cell structure of the other or second cell region are tilted.

The honeycomb structure includes a honeycomb structure body having porous partition walls, and a plugging portion disposed in one of open ends of each cell, a thickness of the partition walls is 0.30 mm or more and 0.51 mm or less, a cell density is 30 cells/cm.sup.2 or more and 93 cells/cm.sup.2 or less, a filtration area (cm.sup.2) of inflow cells included per cm.sup.3 of the honeycomb structure body is defined as an inflow side filtration area G (cm.sup.2/cm.sup.3), a value obtained by dividing a pore volume Vp (cm.sup.3) formed in the partition walls by a total volume Va (L) including the cells is defined as a pore volume ratio A (cm.sup.3/L), and in this case, a product of the inflow side filtration area G (cm.sup.2/cm.sup.3) and the pore volume ratio A (cm.sup.3/L) is 1800 cm.sup.2/L or more and 3200 cm.sup.2/L or less.

A method and modular desulfurization-decarbonization apparatus for removing contaminants from exhaust gas is described. The apparatus comprises discrete modular units with distinct functions. The modular units may be housed in standard shipping containers and installed on cargo ships. The modules can be removed and replaced while docking with minimal disruption to ship and port operations.

A layered catalyst composite for the treatment of exhaust gas emissions, effective to provide lean NO.sub.x trap functionality and three-way conversion functionality is described. Layered catalyst composites can comprise catalytic material on a substrate, the catalytic material comprising at least two layers. The first layer comprising rare earth oxide-high surface area refractory metal oxide particles, an alkaline earth metal supported on the rare earth oxide-high surface area refractory metal oxide particles, and at least one first platinum group metal component supported on the rare earth oxide-high surface area refractory metal oxide particles. The second layer comprising a second platinum group metal component supported on a first oxygen storage component (OSC) and/or a first refractory metal oxide support and, optionally, a third platinum group metal supported on a second refractory metal oxide support or a second oxygen storage component.

A honeycomb structure includes a honeycomb substrate having porous partition walls defining a plurality of cells extending from one end face to the other end face, and one-side plugging portions configured to plug the cells in the one end face in accordance with a predetermined arrangement standard, and the partition walls include catalyst impregnated partition walls formed in a first region of a predetermined length extending from the one end face in which the one-side plugging portions are provided, along an axial direction of the honeycomb substrate and formed by impregnating a catalyst into partition wall inner portions, and catalyst layer partition walls formed in a second region of a predetermined length extending from the other end face along the axial direction of the honeycomb substrate and having catalyst layers which coat partition wall surfaces with the catalyst in the form of layers.

A high-end processing device for purification of exhaust of a diesel engine includes a connection channel, a plurality of catalytic converters, a plurality of direct-passage ceramic filters, and at least one wall-flow filter. The catalytic converters are arranged, in a manner of being spaced from each other, at a front portion of an exhaust gas flow path defined by the connection channel. The direct-passage ceramic filters and the wall-flow filter are arranged, in a manner of being spaced from each other, at a rear portion of the exhaust gas flow path of the connection channel. The direct-passage ceramic filters and the wall-flow filter are impregnated with urea or ammonia and dried so as to reduce nitrogen oxides (NOx) into nitrogen and water to reduce impact to the environment.

An exhaust system that includes a catalytic converter, selective catalytic reduction system, a muffler and, for certain applications, a diesel particulate filter that each include at least one filter that has an electric heating element, a metallic coating and a plurality of metal rods extending therethrough. The combination of elements are configured to heat the internal housings of the exhaust system and disrupt the direction of flow of exhaust gases which contain harmful toxic gases and pollutants and aid in removing and/or reducing said toxic gases and pollutants.