The present application solves the existing problem of using very expensive oxidation reagents, such as H.sub.2O.sub.2 and ozone, in removal of NO.sub.x and SO.sub.x from the flue gases, by performing the NO.sub.x and SO.sub.x oxidation with atmospheric oxygen. The combined system for catalytic oxidation and wet-scrubbing of simultaneously both NO.sub.x and SO.sub.x from a flue gas and manufacturing fertilisers, comprises: (a) an air separation unit for separating atmospheric oxygen from air and thereby producing an air stream substantially enriched with atmospheric oxygen for oxidation of NO.sub.x and SO.sub.x, (b) an adsorption and oxidation reactor containing an oxidation catalyst and designed to receive said air stream and a flue gas stream containing NO.sub.x and SO.sub.x, to adsorb said streamed gases, and then to carry out the catalytic oxidation of said NO.sub.x and SO.sub.x by said oxygen to yield nitric and sulphuric acids, (c) a separator and reactor control unit for separation of products and liquids and controlling said catalytic oxidation and wet-scrubbing; and (d) a vessel containing gas or liquid ammonia, connected to said adsorption and oxidation reactor or to said separator and reactor control unit, and streaming said ammonia into the adsorption and oxidation reactor or into the separator and reactor control unit to react with the nitric and sulphuric acids and to yield ammonium nitrate and ammonium sulphate fertilisers.

The invention relates to a noxious gas purificant and its preparation and purification method for removing nitrogen oxides from gas streams thereof. The preparing method is characterized in that: mixing, according to a predetermined ratio and a process, a salt of iron, manganese, cobalt, or copper, and a related derivative thereof, an alkali or alkaline substance and a related derivative thereof, water and a forming agent, so as to obtain a solid compound or mixture; drying and activating the solid compound or mixture to produce a solid product as the purificant; and introducing the purificant into a gas-solid reactor, and removing noxious gases in a gas stream by performing, in a preconfigured temperature and using the purificant, a gas-solid reaction on the harmful gases in the gas stream. The purificant can be recycled and reused.

The invention discloses a method for simultaneously removing SO.sub.2 and NO.sub.x in flue gas: uniformly mixing a water-soluble ruthenium salt with ammonia water to obtain an aqueous solution of a ruthenium-amine complex; subjecting the flue gas and the aqueous solution of the ruthenium-amine complex to a countercurrent contact reaction under the temperature of 5-60 C., pH of 7.5-12 to obtain a solution A and purified gas; discharging the solution A of the step (2) into a crystallization tank to crystallize and separate an ammonium salt to obtain a solution B, returning the solution B to replace the aqueous solution of the ruthenium-amine complex. The invention utilizes the ruthenium-amine complex having a strong capability of complexing with NO as well as residual oxygen in the flue gas to carry out liquid phase catalytic oxidation to convert the NO.sub.x into ammonium nitrate, the removal efficiency of the NO.sub.x and the SO.sub.2 is high.

A desulfurization absorption tower, a method for setting up the same and a method for operating the same. The tower may include an internal anti-corrosion layer that may be used for contacting the flue gas and the desulfurization absorption liquid, may define the tower chamber, and may include stainless steel plate whose thickness is 1.0 mm to 6.0 mm. The tower body may include an external supporting layer that may be used for supporting the anti-corrosion layer and may include carbon steel. The supporting layer and the anti-corrosion layer may be designed to jointly bear a load, wherein the supporting layer may be designed to bear a large part of the load, and the anti-corrosion layer may be designed to bear a small part of the load.

Presented is a process for the regeneration of a deactivated nitrogen oxide decomposition catalyst used for the selective catalytic reduction of nitrogen oxides contained in a flue gas stream.

A desulfurization absorption tower, a method for setting up the same and a method for operating the same. The tower may include an internal anti-corrosion layer that may be used for contacting the flue gas and the desulfurization absorption liquid, may define the tower chamber, and may include stainless steel plate whose thickness is 1.0 mm to 6.0 mm. The tower body may include an external supporting layer that may be used for supporting the anti-corrosion layer and may include carbon steel. The supporting layer and the anti-corrosion layer may be designed to jointly bear a load, wherein the supporting layer may be designed to bear a large part of the load, and the anti-corrosion layer may be designed to bear a small part of the load.

A desulfurization absorption tower, a method for setting up the same and a method for operating the same. The tower may include an internal anti-corrosion layer that may be used for contacting the flue gas and the desulfurization absorption liquid, may define the tower chamber, and may include stainless steel plate whose thickness is 1.0 mm to 6.0 mm. The tower body may include an external supporting layer that may be used for supporting the anti-corrosion layer and may include carbon steel. The supporting layer and the anti-corrosion layer may be designed to jointly bear a load, wherein the supporting layer may be designed to bear a large part of the load, and the anti-corrosion layer may be designed to bear a small part of the load.

A desulfurization absorption tower, a method for setting up the same and a method for operating the same. The tower may include an internal anti-corrosion layer that may be used for contacting the flue gas and the desulfurization absorption liquid, may define the tower chamber, and may include stainless steel plate whose thickness is 1.0 mm to 6.0 mm. The tower body may include an external supporting layer that may be used for supporting the anti-corrosion layer and may include carbon steel. The supporting layer and the anti-corrosion layer may be designed to jointly bear a load, wherein the supporting layer may be designed to bear a large part of the load, and the anti-corrosion layer may be designed to bear a small part of the load.

The invention relates to a noxious gas purificant and its preparation and purification method for removing nitrogen oxides from gas streams thereof. The preparing method is characterized in that: mixing, according to a predetermined ratio and a process, a salt of iron, manganese, cobalt, or copper, and a related derivative thereof, an alkali or alkaline substance and a related derivative thereof, water and a forming agent, so as to obtain a solid compound or mixture; drying and activating the solid compound or mixture to produce a solid product as the purificant; and introducing the purificant into a gas-solid reactor, and removing noxious gases in a gas stream by performing, in a preconfigured temperature and using the purificant, a gas-solid reaction on the harmful gases in the gas stream. The purificant can be recycled and reused.

A desulfurization absorption tower, a method for setting up the same and a method for operating the same. The lower may include an internal anti-corrosion layer that may be used for contacting the flue gas and the desulfurization absorption liquid, may define the tower chamber, and may include stainless steel plate whose thickness is 1.0 mm to 6.0 mm. The tower body may include an external supporting layer that may be used for supporting the anti-corrosion layer and may include carbon steel. The supporting layer and the anti-corrosion layer may be designed to jointly bear a load, wherein the supporting layer may be designed to bear a large part of the load, and the anti-corrosion layer may be designed to bear a small part of the load.