A method for producing aqueous hydrochloric acid from flue gases is provided. The method comprises conveying water to a first scrubber (102, 202, 302, 402, 502, 602, 702) or to a line (112b, 212b, 312b, 412b, 512b, 712b, 712c) to use the water in a scrubbing liquid of the first scrubber. The method also comprises providing flue gas containing chlorides into the first scrubber (102, 202, 302, 402, 502, 602, 702) and scrubbing the flue gas containing chlorides with the scrubbing liquid by contacting the flue gas with the scrubbing liquid in the first scrubber (102, 202, 302, 402, 502, 602, 702). Dilute hydrochloric acid and a flue gas derivate (104, 204, 304, 404, 504, 704) are produced. The method comprises letting out at least some of the dilute hydrochloric acid from the first scrubber (102, 202, 302, 402, 502, 602, 702) as a scrubber bleed, separating solids suspended by the scrubber bleed in a solids separator (192, 592, 692), conveying the scrubber bleed from the solids separator (192, 592, 692) into an evaporation vessel (194, 594, 694) and concentrating the scrubber bleed in the evaporation vessel (194, 594, 694) to produce hydrochloric acid vapor having a concentration of 5-22 wt-%. A corresponding system is also provided.

Systems for reducing the content of residual pollutants from tailpipes emissions in an exhaust line having a cold part may include an ozone generation system; an MnO.sub.2 catalyst; and a lean NO.sub.x trap (LNT) catalyst. In these systems, the ozone, MnO.sub.2 catalyst, and LNT catalyst may be provided in the cold part of the exhaust line. In these systems, the residuals pollutants may be oxidized at temperatures of from about 20° C. to about 150° C. in rich or lean conditions and NO.sub.2 may have a concentration of less than 0.1 mg/km in the tailpipe emissions downstream of the cold part of the exhaust line. Corresponding methods may include generating ozone from an ozonizer; injecting the ozone in a mixing chamber comprising the residual pollutants to form a first mixture; converting the first mixture using an MnO.sub.2 catalyst to form a second mixture; and converting the second mixture using an LNT catalyst.

A catalyst arrangement deciding method for a flue gas denitrizer including a catalyst layer disposed in an exhaust gas passage includes: a step of investigating a location dependence of a degradation state of a catalyst in the catalyst layer after a lapse of a period of operation; and a step of deciding a first region of the catalyst layer in which a first catalyst is used and a second region of the catalyst layer in which a second catalyst different from the first catalyst is used, on the basis of the location dependence.

Systems for reducing the content of residual pollutants from tailpipes emissions in an exhaust line having a cold part may include an ozone generation system; an MnO.sub.2 catalyst; and a lean NO.sub.x trap (LNT) catalyst. In these systems, the ozone, MnO.sub.2 catalyst, and LNT catalyst may be provided in the cold part of the exhaust line. In these systems, the residuals pollutants may be oxidized at temperatures of from about 20° C. to about 150° C. in rich or lean conditions and NO.sub.2 may have a concentration of less than 0.1 mg/km in the tailpipe emissions downstream of the cold part of the exhaust line. Corresponding methods may include generating ozone from an ozonizer; injecting the ozone in a mixing chamber comprising the residual pollutants to form a first mixture; converting the first mixture using an MnO.sub.2 catalyst to form a second mixture; and converting the second mixture using an LNT catalyst.

A control device for controlling a flue gas denitrizer including a reductant supply part for supplying a reductant to an exhaust gas passage to which an exhaust gas from a boiler is introduced. The control device comprises: a storage part which stores a plurality of opening degree patterns of a plurality of first valves corresponding to a plurality of operational states of the boiler respectively; an opening degree pattern acquisition part configured to acquire an opening degree pattern corresponding to a present operational state of the boiler among the plurality of opening degree patterns from the storage part; and a first valve control part configured to regulate an opening degree of each of the plurality of first valves, on the basis of the opening degree pattern acquired by the opening degree pattern acquisition part.

A reactor for reducing the concentration of NO.sub.x in a stream comprising: an inlet for the stream; an outlet for a stream containing a reduced concentration of NO.sub.x ; one or more catalyst beds comprising a ceramic or metallic foam with a NO.sub.x reduction catalyst; one or more flow paths from the inlet to the outlet that passes through at least one catalyst bed wherein the catalyst beds are closed at the top and bottom so that the flow path through the catalyst bed passes through the sides of the catalyst bed in a lateral flow is described.

A method for regenerating a deactivated denitration catalyst includes steps of preparing a washing fluid including a water-contained liquid and entrained carbon dioxide bubbles, and subjecting the deactivated denitration catalyst to a treatment with the washing fluid. An apparatus for regenerating the deactivated denitration catalyst is also provided.

An exhaust gas treatment device includes an exhaust gas line where a combustion exhaust gas discharged from a power generation facility flows through, an exhaust gas line where a second combustion exhaust gas discharged from a second power generation facility flows through, exhaust gas exhaust line disposed by branching off from exhaust gas line, discharging a part of combustion exhaust gases as exhaust combustion exhaust gases, a nitrogen oxide removing unit removing nitrogen oxide contained in an integrated combustion exhaust gas that integrates the combustion exhaust gases, an integrated waste heat recovery boiler recovering waste heat from the integrated combustion exhaust gas, and a CO.sub.2 recovery unit recovering CO.sub.2 contained in the integrated combustion exhaust gas by using CO.sub.2 absorbing liquid.

A combustion device burns fuel ammonia in a combustion chamber using compressed combustion air, and includes a combustion air cooling unit which is configured to cool the combustion air by heat exchange with the fuel ammonia during or before a compression process.

The invention relates to an intelligent multi-pollutant ultra-low emission system and a global optimization method thereof. The intelligent multi-pollutant ultra-low emission system comprises a device layer, a sensing layer, a control layer and an optimization layer from bottom to top. The global optimization method comprises: obtaining an accurate description multiple pollutants in the generation, migration, transformation and removal process in multiple devices by means of accurate modeling of a multi-device multi-pollutant simultaneous removal process of the ultra-low emission system; accurately evaluating multi-pollutant emission reduction costs under different loads, coal qualities, pollutant concentrations and operating parameters through a global operating cost evaluation method of the ultra-low emission system; realizing minute-level planning and optimization of emission reductions of a global pollutant emission reduction device under different emission targets through a multi-pollutant, multi-target and multi-condition global operating optimization method; and guaranteeing reliable emission reduction and margin control of the pollutants through an advanced control method for reliable up-to-standard ultra-low emission of the pollutants.