Zeolite catalysts and systems and methods for preparing and using zeolite catalysts having the CHA crystal structure are disclosed. The catalysts can be used to remove nitrogen oxides from a gaseous medium across a broad temperature range and exhibit hydrothermal stable at high reaction temperatures. The zeolite catalysts include a zeolite carrier having a silica to alumina ratio from about 15:1 to about 256:1 and a copper to alumina ratio from about 0.25:1 to about 1:1.

An injector mixer arrangement (10) for supplying a reducing agent in gaseous form into a flue gas flowing in a gas duct (14) communicating with a catalyst (18a) in a selective catalytic reduction (SCR) reactor (12) arranged downstream of said injector mixer arrangement (10). The injector mixer arrangement (10) comprises an injector grid (22) equipped with a plurality of nozzles (30) arranged horizontally within the gas duct (14). The nozzles (30) are adapted to supply said reducing agent to the gas duct (14). The injector mixer arrangement (10) further comprises first stage mixer plates (24) and second stage mixer plates (26) arranged in the gas duct (14) downstream of said nozzles (30) and upstream of SCR reactor 12.

A method and a system (12) for reducing plant (10) gas emissions by reducing ammonia/ammonium ion content in waste water W prior to the waste water W being evaporated in an evaporator device (7). As such, the method and the system (12) reduce the release of ammonia/ammonium ion into the flue gas FG stream thus reducing emissions of ammonia/ammonium ions to the environment or atmosphere and/or accumulation of ammonia/ammonium ions in downstream equipment such as a wet flue gas desulfurization system (13).

The present invention relates to a method for inhibiting the formation of dioxin-like compounds in solid waste incineration flue gases, belonging to the field of cleaning of solid waste incineration flue gases. In accordance with the present invention, when incineration flue gases cool down to 500450 C., the flue gases are introduced into an inhibition reactor where copper chlorides in flue gas particulates mix and react with inhibitors to convert into copper metaphosphate so as to inactivate the copper chlorides which can catalyze the formation of dioxin-like compounds and control dioxin-like compound pollutants in incineration flue gases at the source. Compared with the prior art, the invention can effectively control the main formation ways of dioxin-like compounds in solid waste incineration flue gases by optimizing inhibitors and reaction conditions. The method of the invention does not affect the residual heat utilization of solid waste incineration flue gases, so solid waste incineration has a better resource utilization effect. The ammonium dihydrogen phosphate inhibitor used in the invention has the advantages of high inhibition efficiency, strong operability, low cost and environment protection, providing the technology with good application feasibility.

Processes and systems for producing potassium sulfate as a byproduct of a desulfurization process. Sulfur dioxide is absorbed from a flue gas using an ammonia-containing solution to produce an ammonium sulfate solution that contains dissolved ammonium sulfate. At least a first portion of the ammonium sulfate solution is heated before dissolving potassium chloride therein to form a slurry that contains potassium sulfate crystals and an ammonium chloride solution. The slurry is then cooled to precipitate additional potassium sulfate crystals, after which the potassium sulfate crystals are removed to yield a residual ammonium chloride solution that contains dissolved ammonium chloride and residual dissolved potassium sulfate. Ammonia is then absorbed into the residual ammonium chloride solution to further precipitate potassium sulfate crystals, which are removed to yield a residual ammonium chloride solution that is substantially free of dissolved potassium sulfate.

The present invention pertains to new methods for generating energy and useful nitrogen compounds from captured carbon dioxide. It involves employing an osmotic engine, draw solution, and feed solution. An osmotic gradient between the solutions assists in generating energy and a solution of ammonium carbonate, ammonium bicarbonate or mixture thereof. This solution may be decomposed to form ammonia, carbon dioxide, a precipitate, or a mixture thereof.

An assembly (10) for introducing a reducing agent into the exhaust pipe (12) of an exhaust system of an internal combustion engine, in particular of a motor vehicle, has a feed connector (14) which opens into the exhaust pipe (12) and includes a wall (16), a feed device (20) for reducing agents which opens into the feed connector (14), and a device (22) for generating a gas flow (G) which is additional to the reducing agent flow (R) and lines the wall (16) of the feed 10 connector (14). Furthermore, there is described a method of introducing a reducing agent into the exhaust pipe (12) of an exhaust system of an internal combustion engine, in particular of a motor vehicle.

A formulation and process for capturing CO.sub.2 use an absorption mixture containing water, biocatalysts and a carbonate compound. The process includes contacting a CO.sub.2-containing gas with the absorption mixture to enable dissolution and transformation of CO.sub.2 into bicarbonate and hydrogen ions, thereby producing a CO.sub.2-depleted gas and an ion-rich solution, followed by subjecting the ion-rich solution to desorption. The biocatalyst improves absorption of the mixture comprising carbonate compounds and the carbonate compound promotes release of the bicarbonate ions from the ion-rich solution during desorption, producing a CO.sub.2 gas stream and an ion-depleted solution.

An exhaust system for an internal combustion engine is disclosed. The exhaust system comprises a particulate filter, one or more NO.sub.x reduction catalysts, and a low pressure exhaust gas recirculation (EGR) circuit for connecting the exhaust system downstream of the filter and the one or more NO.sub.x reduction catalysts to an intake of the engine. The EGR circuit comprises a N.sub.2O-producing catalyst.

A mercury sorbent and method for enhancing mercury removal performance of activated carbon from flue gas by the addition of non-halogen ammonium-containing compounds are provided herein.