The subject invention provides systems and methods for capturing carbon dioxide in a cyclic process of mechano-chemical reactions. The subject invention also provides systems and methods for synthesizing siderite, by means of mechano-chemical reactions, using mill rotation. Siderite acts as an efficient reversible sorbent and can be decomposed, generating magnetite, carbon and/or metallic iron as well as pure carbon dioxide. Said systems and methods employing carbon dioxide capture/release reactions in the carbonation-calcination cycles are suitable for using in any iron, steel and non-steel industries to reduce carbon dioxide emissions into the atmosphere.

Disclosed is an absorbing liquid for separating and capturing carbon dioxide from a carbon dioxide-containing gas, the absorbing liquid containing: at least one alkanolamine represented by formula (1) ##STR00001##
wherein R.sup.1 represents hydrogen or C.sub.1-4 alkyl, R.sup.2 and R.sup.3 are identical or different and each represent hydrogen or C.sub.1-3 alkyl, R.sup.1, R.sup.2, and R.sup.3 are not all hydrogen, and n is 1 or 2; a low-molecular-weight diol compound and/or glycerin; and water.

The invention relates to a method of reducing carbon dioxide and metal-containing dust and, more particularly, to a method of simultaneously reducing carbon dioxide and metal-containing dust by passing an off-gas, which contains carbon dioxide or carbon dioxide and metal-containing dust, through a reactor in which a sulfur-oxidizing microorganism is grown using carbon dioxide as a carbon source to produce sulfuric acid, and producing metal sulfates (MeSO.sub.4) by reaction of the produced sulfur acid with metal components present in the off-gas.

The present invention relates to a system and method for desulfurization and denitrification integrated treatment and recycling of flue gas by using red mud, and belongs to the recycling and environmental protection technology field. The system includes a desulfurization spray tower, an ozone generator, a denitration spray tower, a slurry mixing tank, a slurry storage tank, a vacuum filter, an ammonia water neutralization tank, an aluminum hydroxide precipitation tank, an ammonia water tank, an aluminum hydroxide storage tank, a filter press, an ammonia distillation tower, a dephlegmator, a cooler, a concentrated ammonia water storage tank, a gypsum precipitation tank, and an anaerobic biochemical pool. In the present invention, red mud slurry is used for desulfurization and denitrification treatment of flue gas to remove SO.sub.2 and NO in the flue gas, so that SO.sub.2 and NO in the flue gas reach an emission standard.

The present invention discloses a method and device for purifying CO from a flue gas and coupling-suppressing white fog, where the flue gas is introduced into a ceramic honeycomb carrier coated with a CO catalyst, sufficient O.sub.2 in the flue gas is utilized to generate CO.sub.2 from a low concentration of CO through catalytic oxidation, so as to achieve the purpose of purifying CO, and the flue gas is heated up by the heat released from the catalytic oxidation reaction to more than 110 C. and then discharged into the air, which meets the temperature requirement of coupling-suppressing white fog; the device includes a CO concentration sensor, a temperature sensor, a CO catalytic oxidation layer, an oxidation reaction tower, a desulfurized sintering flue gas, a packing layer I, a packing layer II, a chimney, and a solenoid valve II.

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.

This invention is directed to a method used to remove gases from industrial exhaust streams, and in particular, to a method for removing sulfur dioxide from flue gases, with molten carbonate and treating the resulting molten mixture with a natural gas and optionally with an oxidant.

A method is described for preparing a sorbent including the steps of: (i) mixing together a particulate copper sulphide material, a particulate support material and one or more binders, (ii) shaping the mixture, and (iii) drying the shaped mixture to form a dried sorbent.

A process for operating an oxidizable combustion gas cleaning unit in a metallurgical plant, including the steps of: (a) passing an oxidizable combustion gas from a metallurgical reactor, in particular a blast furnace gas from a blast furnace, in a packed bed scrubber arrangement through a packed bed in countercurrent with a washing water or in a spray scrubber arrangement to remove cyanide compounds, in particular hydrogen cyanide, and to increase the removal of chloride compounds, in particular hydrogen chloride, from the combustion gas by solubilizing the cyanide and chloride compounds in the washing water, (b) collecting the washing water containing solubilized cyanide and chloride compounds at a bottom end of the packed bed or spray scrubber arrangement, and (c) collecting a cleaned oxidizable combustion gas at a top of the packed bed or spray scrubber arrangement, wherein a base is added to the washing water before step (a).

The subject invention provides systems and methods for capturing carbon dioxide in a cyclic process of mechano-chemical reactions. The subject invention also provides systems and methods for synthesizing siderite, by means of mechano-chemical reactions, using mill rotation. Siderite acts as an efficient reversible sorbent and can be decomposed, generating magnetite, carbon and/or metallic iron as well as pure carbon dioxide. Said systems and methods employing carbon dioxide capture/release reactions in the carbonation-calcination cycles are suitable for using in any iron, steel and non-steel industries to reduce carbon dioxide emissions into the atmosphere.