A flow-through solid catalyst formed by coating a zeolite material on a metal or ceramic solid substrate. In some embodiments, the solid substrate is formed as flat plates, corrugated plates, or honeycomb blocks.

The present invention relates generally to the field of emission control equipment for boilers, heaters, kilns, or other flue gas-, or combustion gas-, generating devices (e.g., those located at power plants, processing plants, etc.) and, in particular to a new and useful method and apparatus for reducing or preventing the poisoning and/or contamination of an SCR catalyst. In still another embodiment, the present invention relates to a method and apparatus for increasing the service life and/or catalytic activity of an SCR catalyst while simultaneously controlling various emissions. In yet another embodiment, the present invention relates to a method and apparatus for controlling, mitigating and/or reducing the amount of selenium contained in and/or emitted by one or more pieces of emission control equipment for boilers, heaters, kilns, or other flue gas-, or combustion gas-, generating devices (e.g., those located at power plants, processing plants, etc.).

The present invention relates to a new strategy for capturing NO.sub.x using a two-step process.

A process for the removal of hydrogen sulfide and sulfur recovery from a H.sub.2S-containing gas stream by catalytic direct oxidation and Claus reaction through two or more serially connected catalytic reactors, wherein a specific control of the oxygen supplement is operated. The control and improvement of the process is obtained by complementing, in each major step of the process, the H.sub.2S-containing gas stream by a suitable flow of oxygen, namely before the H.sub.2S-containing gas stream enters the Claus furnace, in the first reactor of the process and in the last reactor of the process. Especially in application in a SubDewPoint sulfur recovery process the H.sub.2S/SO.sub.2 ratio is kept constant also during switch-over of the reactors R1 and R by adding the last auxiliary oxygen containing gas directly upstream the last reactor R so that the H.sub.2S/SO.sub.2 ratio can follow the signal of the ADA within a few seconds.

Ho Honeycomb monolith structure, especially for use in mass transfer-limited processes or processes for the selective catalytic reduction (SCR) of nitrogen oxides, comprising: a plurality of cell walls defining a plurality of polygonal channels, the plurality of cell walls and channels extending in parallel along a common direction from an entrance end to an outlet end of the structure in the fluid flow direction. The transversal cross section of a polygonal channel has the shape of a convex elongated polygon, wherein at least 50% of the internal angles between two adjacent walls of the convex polygon are above 90 degrees and wherein the cell diameter ratio L.sub.L/L.sub.S is greater than 1.5.

A multifunctional air purifying device for removing indoor pollution by a thermal decomposition method comprises an air treatment unit and an air collection heater. The air collection heater is provided with an infrared lamp tube and an ultraviolet lamp tube. An annular water tank is arranged on an inner side of the upper part of the air treatment unit. A filter screen runs through the annular water tank and is connected with an air cap, and a fan is provided at a joint between the filter screen and the air cap. The filter screen includes an early effect filter screen, a HEPA filter screen, an activated carbon filter screen and a cold catalyst filter arranged in that order from a bottom to a top. A humidifier connects the annular sink and a nozzle located at an exhaust port.

Provided is an ammonia slip catalyst article having supported palladium in a top or upstream layer for oxidation of carbon monoxide and/or hydrocarbons, an SCR catalyst either in the top layer or in a separate lower or downstream layer, and an ammonia oxidation catalyst in a bottom layer. Also provided are methods for treating an exhaust gas using the catalyst article, wherein the treatment involves reducing the concentrations of ammonia and optionally carbon monoxide and/or hydrocarbons in the exhaust gas.

Organic sulfur compounds contained in refinery off gas streams having either high ort low concentrations of olefins are converted to hydrogen sulfides which can be then be removed using conventional amine treating systems. The process uses a catalytic reactor with or without a hydrotreater depending on the olefin concentration of the off gas stream. The catalytic reactor operates in a hydrogenation mode or an oxidation mode to convert a majority of organic sulfur compounds into hydrogen sulfides.

Provided is a renewable wet desulfurization process using a suspension bed, comprising mixing the desulfurization slurry with a hydrogen sulfide containing gas to obtain a first mixture, and passing the first mixture into a suspension bed reactor from bottom to top, with controlling the first mixture to have a dwell time of 5-60 minutes in the suspension bed reactor to allow they contact and react sufficiently with each other; and subjecting a second mixture obtained from the reaction to gas liquid separation to produce a rich solution and a purified gas, subjecting the resulting rich solution to flash evaporation and then reacting with an oxygen-containing gas for carrying out regeneration. The process of the present invention may reduce the hydrogen sulfide content in the hydrogen sulfide containing gas from 2.4-140 g/Nm.sup.3 to 50 ppm or less, so that the desulfurization efficiency is 98% or more. The present invention can achieve regeneration of a spent desulfurizer with a regeneration efficiency as high as 65%-83%, and the barren solution obtained by the regeneration may be recycled for being used as the desulfurization slurry, without generating secondary pollution, which is very suitable for industrial promotion.

Provided is a wet desulfurization process using a suspension bed. The process comprises mixing desulfurization slurry with a hydrogen sulfide containing gas to obtain a first mixture, and passing the first mixture into a suspension bed reactor from bottom to top, with controlling the first mixture to have a dwell time of 5-60 minutes in the reactor to allow they contact and react sufficiently with each other; and subjecting a second mixture obtained from the reaction to gas liquid separation to produce a purified gas. The process of the present invention may reduce the hydrogen sulfide content in the hydrogen sulfide containing gas from 2.4-140 g/Nm.sup.3 to 50 ppm or less, so that the desulfurization efficiency is 98% or more. The process of the present invention is simple and reasonable, with high desulfurization and regeneration efficiency, simple equipment, little occupation of land and low investment, which is very suitable for industrial promotion.