Chromium particulate emissions in flue gas can be reduced or minimized by incorporating a thin layer bed of a catalyst within the flue gas flow path of a furnace, boiler, or other furnace environment that includes Cr-containing surfaces. The thin layer bed of catalyst can correspond to, for example, a honeycomb monolith with catalyst supported on the monolith surface, so as to provide a high contact area while forcing all of the flue gas to pass through the catalyst bed. The honeycomb monolith structure and the depth of the bed can be selected to provide a reduced or minimized pressure drop across the catalyst bed, such as a pressure drop of 0.25 kPa (1.0 inches of water) or less. Exposing the Cr-containing flue gas to the thin layer catalyst bed can result in a treated flue gas with a lower content of Cr.

Some embodiments of the present disclosure relate to a method of regenerating at least one filter medium comprising: providing at least one filter medium, wherein the at least one filter medium comprises: at least one catalyst material; and ammonium bisulfate (ABS) deposits, ammonium sulfate (AS) deposits, or any combination thereof; flowing a flue gas stream transverse to a cross-section of a filter medium, such that the flue gas stream passes through the cross section of the at least one filter medium, wherein the flue gas stream comprises: NOx compounds comprising: Nitric Oxide (NO), and Nitrogen Dioxide (NO.sub.2); and increasing an NOx removal efficiency of the at least one filter medium after removal of deposits.

A catalyst containing a washcoat including copper or iron on a small pore molecular sieve material having a maximum ring size of eight tetrahedral atoms physically mixed with platinum and rhodium on a refractory metal oxide support including alumina, silica, zirconia, titania, and a physical mixture or a chemical combination or an atomically doped combination thereof is described. A catalyst containing a first washcoat zone substantially free of platinum group metal and including copper or iron on a small pore molecular sieve material having a maximum ring size of eight tetrahedral atoms; and a second washcoat zone including copper or iron on a small pore molecular sieve material having a maximum ring size of eight tetrahedral atoms physically mixed with platinum or platinum and rhodium on a refractory metal oxide support including alumina, silica, zirconia, titania, and a physical mixture or a chemical combination or an atomically doped combination thereof is provided. A method and a system for treating emissions using the catalyst are also described.

A method for flue gas denotation includes the step of, in the presence of ammonia, enabling flue gas in a denitration reactor to pass through a plurality of catalyst beds from the bottom to the top to participate in a denitration reaction. Each catalyst bed contains a catalyst support component and a granular denitration catalyst stacked on the catalyst support component, and, in every single catalyst bed, the granular denitration catalyst moves along a same direction on the catalyst support component. Between every two adjacent catalyst beds, the granular denitration catalyst falls from the tail of a previous catalyst support component to the head of a next catalyst support component, making the granular denitration catalyst travel along the catalyst support components reciprocatively.

The present invention relates to catalyst compositions containing a mixed oxide catalyst of formula (I) or formula (II) as described herein, their preparation, and their use in a process for ammoxidation of various organic compounds to their corresponding nitriles and to the selective catalytic oxidation of excess NH.sub.3 present in effluent gas streams to N.sub.2 and/or NO.sub.x.

A process for the treatment of waste water, spent air, and hydrocarbon containing liquid and gaseous streams in the cumene/phenol complex is described. Various effluent streams are combined in appropriate collection vessels, including a spent air knockout drum, a hydrocarbon buffer vessel, a fuel gas knockout drum, a phenolic water vessel, and a non-phenolic water vessel. Streams from these vessels are sent to a thermal oxidation system.

The present disclosure provides msect-4 molecular sieves with OFF and ERI topologies, a preparation method therefor, and applications thereof. An eight-membered ring small pore molecular sieve used as a raw material is dispersed in an aqueous phase. Following that, caustic potash, an aluminum source, and an organic structure-directing agent (OSDA) are added. The pH value is then adjusted to be greater than 10, and a silicon source is introduced to attain the desired silicon-aluminum ratio, followed by stirring reaction, aging, crystallization, filtration, washing, ammonia exchange reaction, drying, and calcination. The msect-4 molecular sieves with OFF and ERI topologies, the preparation method therefor, and applications exhibit excellent hydrothermal stability, a plurality of adsorption sites exposed by a regular bone-like structure, and a large specific surface area. Consequently, this molecular sieves find applicability across various technical fields including selective catalytic reduction, passive adsorption, and catalytic cracking, and has broad application prospects.

The present invention pertains to a catalyst for use in the selective catalytic reduction (SCR) of nitrogen oxides comprising a monolithic substrate and a coating A, which comprises an oxidic metal carrier comprising an oxide of titanium and a catalytic metal oxide which comprises an oxide of vanadium wherein the mass ratio vanadium/titanium is 0.07 to 0.26.

Some non-limiting embodiments of the present disclosure relate to a method of regenerating at least one filter medium, the method comprising flowing a flue gas stream through or by the at least one filter medium at a first temperature and increasing the temperature of the flue gas stream from the first temperature to a second temperature that exceeds the first temperature. Some non-limiting embodiments of the present disclosure relate to a method of cleaning a flue gas stream, the method comprising maintaining the NO.sub.x removal efficiency by increasing the temperature of the flue gas stream from the first temperature to a second temperature that exceeds the first temperature.

A method for purifying combustion exhaust gas, comprising: placing a denitration catalyst in gas stream to remove nitrogen oxides from a combustion exhaust gas, wherein the denitration catalyst comprises a shaped product comprising a catalyst component and having microcracks on the surface of the shaped-product, and 80% to 100% of the microcracks on the number basis have an angle of a longitudinal direction of the microcracks with respect to a main direction of the gas stream within ±30 degrees.