A catalyst bed comprising a ceramic or metallic foam comprising one or more NO.sub.x reduction catalysts is described. A method for reducing the concentration of NO.sub.x in a dust containing gas stream comprising: a) passing a first gas stream containing NO.sub.x into a contacting zone; b) contacting the first gas stream with a ceramic or metallic foam catalyst bed having one or more flow paths through the catalyst bed wherein the ceramic or metallic foam comprises a NO.sub.x reduction catalyst to produce a second gas stream with a reduced NO.sub.x concentration; and c) passing the second gas stream out of the contacting zone wherein the first gas stream has a dust concentration of at least 5 mg/Nm.sup.3 and the pressure drop of the foam catalyst bed increases by 300% or less relative to the initial pressure drop of the foam catalyst bed due to dust accumulation, measured under the same conditions is also described.

The invention relates to an apparatus (1) for catalytic decomposition of nitrous oxide in a gas stream derived from exhalation air from a patient. The apparatus (1) comprises an inlet arrangement (2) with a gas inlet (3) for the exhalation air, an outlet arrangement (11) with a gas outlet (12) for an outlet gas, and between these arrangements a through-flow decomposition chamber (9) containing a catalyst material. According to the invention the apparatus is provided with a nitrous oxide adsorption/desorption means (4) in the inlet arrangement (2) for level out variations in the concentration of nitrous oxide fed to the decomposition chamber (9).

An improved cluster-supporting catalyst has heteroatom-removed zeolite particles, and catalyst metal clusters supported within the pores of the heteroatom-removed zeolite particles. A method for producing a cluster-supporting catalyst includes the following steps: providing a dispersion liquid containing a dispersion medium and the heteroatom-removed zeolite particles dispersed in the dispersion medium; and in the dispersion liquid, forming catalyst metal clusters having a positive charge, and supporting the catalyst metal clusters within the pores of the heteroatom-removed zeolite particles through an electrostatic interaction.

This disclosure provides an apparatus and method for reducing emissions of nitrogen oxides (NO.sub.x) from a combustion source. For example, a method and apparatus for injecting a urea solution directly into the flue gas stream of a coal-fired power plant that utilizes Selective Catalytic Reduction (SCR) to lower NO.sub.x emissions.

A method for simultaneous removal of NO and carbonic particles and inorganic dust from flue gases in a reactor with a catalyst for direct decomposition of nitric oxide located on a metallic monolith, includes tangential introduction of flue gases to the reactor circumference. Flue gases flow rotationally and downwards in the reactor in contact with an undulating surface of metallic foil located on an inner wall of the reactor chamber and in contact with the catalyst on a spiral band falling to the lower part of the reactor, and next flue gases jet direction counter-currently to a cylindrical inner chamber containing slices of the monolithic catalyst disturbing laminar flow of the flue gases jet. The reactor arrangement provides for simultaneous removal of NO and carbon particles and inorganic dust from flue gases.

The invention relates to a face mask arrangement for alternately administering a gas I containing nitrous oxide and a gas II devoid of nitrous oxide to a patient, comprising a face mask, two inlet flow lines I and II for gas I and a gas II, respectively, which flow lines end in a breathing interface, and an outlet flow line for evacuation of exhaled gas. The two inlet flow lines merge into a common inlet part. Each of the inlet flow lines I and II comprises an inlet valve I and II, each of which is capable of opening in response to inhalation and of closing in response to exhalation. The arrangement comprises a switching means enabling switching between inhalation through inlet flow line I and inlet flow line II depending on the patient's immediate need of gas I or gas II. The invention relates also to a system comprises the face mask arrangement and an apparatus for collecting inhalation air from patients inhaling gas containing nitrous oxide and to the use of the face mask arrangement for administration of nitrous oxide to a patient via inhalation and collecting nitrous oxide from exhaled air of a patient during the administration.

A method of reducing NO.sub.x in tail gas obtained during startup of a plant for preparing nitric acid may involve heating the tail gas from a starting temperature T.sub.0, through a threshold temperature T.sub.G, to an operating temperature T.sub.B at which steady-state operation of the plant can occur (T.sub.0<T.sub.G<T.sub.B). NO.sub.x-containing tail gas may be passed through a storage medium and at least partially stored while the temperature of the tail gas is lower than the threshold temperature T.sub.G. The NO.sub.x may be released, preferably when the temperature of the tail gas has attained the threshold temperature T.sub.G. The NO.sub.x may be combined with a reducing agent in the presence of an SCR catalyst after the temperature of the tail gas has exceeded the threshold temperature T.sub.G, but not before, resulting in catalytic reduction of at least a portion of the NO.sub.x.

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 and/or eliminating various liquid discharges from one or more emission control equipment devices (e.g., one or more wet flue gas desulfurization (WFGD) units). In another embodiment, the method and apparatus of the present invention is designed to reduce and/or eliminate the amount of liquid waste that is discharged from a WFGD unit by subjecting the WFGD liquid waste to one or more drying processes, one or more spray dryer (or spray dry) absorber processes, and/or one or more spray dryer (or spray dry) evaporation processes.

Process for cleaning an off-gas containing sulphur oxides (SOx), nitrogen oxides (NOx) and particulate matter employing SOx adsorption and ammonia-SCR in one filtration unit, in particular a filter bag house with one or more catalysed fabric filter assemblies.

Method and system for the removal of nitrogen oxides, from flue gas at low temperatures.