The present invention belongs to the flue gas desulfuration field. Specifically, the present invention relates to a supported solid-phase catalyst for oxidizing the by-product magnesium sulfite in a magnesium desulfuration process, and to preparation method and use thereof. The catalyst uses an activated carbon particle as a support, and cobalt nitrate, manganese nitrate, copper nitrate and ferrous nitrate as catalytically active components. The preparation method is as follows: mixing the pre-treated activated carbon support with the catalytically active components, followed by oscillating, standing under microwave irradiation, filtrating, drying, baking, so as to obtain the supported solid-phase catalyst. Raw materials of the present invention are inexpensive and easily available; the preparation process is simple; the catalyst has prominent catalytic effect and can be widely used in the magnesium desulfuration process in medium-sized and small-sized boilers of 75t or more to improve the recovery rate of the desulfuration by-product and reduce energy consumption of the oxidation system; the catalyst has a low amount of catalytically active components and causes low residue in the solution and hence no secondary pollution problem, and has a high generalization value.

A method for improving effectiveness of a steam generator system includes providing air to an air preheater at a mass flow such that the air preheater has a cold end outlet temperature defined by the improved air preheater operating with increased heat recovery (HR) of at least 1% calculated according to the equation: HR=100%?((Tgi?TgoAdvX)/(Tgi?TgoSTD)?1). The method requires either reducing the amount of heat that flows into the air preheater from the flue gas and/or increasing the amount of heat extracted from the flue gas. The method includes mitigating SO.sub.3 in the flue gas which is discharged directly from the air preheater to a particulate removal system and then directly into a flue gas desulfurization system. The method includes extracting heat from the Flue gas to create equipment preheat and/or flue gas stack reheat air with the latter being fed to heat the flue gas prior to entering a discharge stack to raise the temperature of the flue gas to mitigate visible plume exiting and to mitigate corrosion in, the discharge stack.

Apparatus and methods for denitrification and desulfurization of and dust removal from an FCC tail gas by an ammonia-based process. The apparatus may include a first-stage waste heat recovery system, a denitrification system, a dust removal and desulfurization system, a tail gas exhaust system, and an ammonium sulfate post-processing system. The dust removal and desulfurization system may include a dedusting tower and an absorption tower disposed separately. The top and the bottom of the absorption tower may be connected respectively to the tail gas exhaust system and the ammonium sulfate post-processing system. The absorption tower may include sequentially, from bottom to top, an oxidation section, an absorption section, and a fine particulate control section. The methods may be implemented with the apparatus.

Methods, apparatus, and compositions for cleaning gas. The use of segmented multistage ammonia-based liquid spray with different oxidation potentials to remove sulfur compounds from gas. The use of different oxidation potentials may reduce unwanted ammonia slip.

Methods, apparatus, and compositions for cleaning gas. The use of segmented multistage ammonia-based liquid spray with different oxidation potentials to remove sulfur compounds from gas. The use of different oxidation potentials may reduce unwanted ammonia slip.

Apparatus and methods for controlling aerosol production during absorption in ammonia desulfurization, by removing sulfur dioxide in flue gas with an absorption circulation liquid containing ammonium sulfite, so as to control the aerosol production during absorption in ammonia desulfurization. Efficient desulfurization and dust removal may be achieved by staged solution composition control and reaction condition control. At the same time ammonia escape and aerosol production during absorption may be controlled. The flue gas may be subjected to preliminary temperature lowering and purification, and may be allowed to contact with an absorption circulation liquid and a fine particle washing circulation liquid sequentially. Levels of solution compositions and reaction temperatures may be controlled.

A process for treating a sulfurous fluid to form gypsum and magnesium carbonate, whereby the sulfurous fluid is scrubbed with a sequestrating agent to yield a scrubbed fluid, gypsum and magnesium sulfate. The flue gas desulfurized gypsum is isolated from the magnesium sulfate solution by filtration or centrifugation. The magnesium sulfate is reacted with a carbonate salt to produce a magnesium carbonate whereby the reaction conditions are controlled to control the properties of the magnesium carbonate produced.

Apparatus and methods for controlling aerosol production during absorption in ammonia desulfurization, by removing sulfur dioxide in flue gas with an absorption circulation liquid containing ammonium sulfite, so as to control the aerosol production during absorption in ammonia desulfurization. Efficient desulfurization and dust removal may be achieved by staged solution composition control and reaction condition control. At the same time ammonia escape and aerosol production during absorption may be controlled. The flue gas may be subjected to preliminary temperature lowering and purification, and may be allowed to contact with an absorption circulation liquid and a fine particle washing circulation liquid sequentially. Levels of solution compositions and reaction temperatures may be controlled.

A system for relocating polluted air includes a tubular chamber with an inlet at one end, an outlet at a end, and auxiliary venturi inlets between the inlet and the outlet. There is at least one fan arranged within the tubular chamber. The fan flows air from outside of the tubular chamber, through the tubular chamber and out of the tubular chamber through the outlet. A compression chamber compresses air before entering the heating chamber. There is at least one heating element within the heating chamber. The heating element(s) heat the air, thereby increasing the velocity of the air through the tubular chamber. The air exits the tubular chamber through the outlet, directed vertically and upward towards upper strata of the atmosphere to redirect the air (and pollutants) into the upper strata of the atmosphere. In some embodiments, filters and scrubbers are provided within the tubular chamber for reducing pollutants.

Provided is an exhaust gas purifying apparatus capable of purifying exhaust gas by using water. The exhaust gas purifying apparatus includes an electrolyzed alkaline water generator which includes a cathode and an anode formed of Mg or an Mg alloy, and in which water is electrolyzed through application of voltage across the cathode and anode, to generate electrolyzed alkaline water. The purifying apparatus includes an exhaust gas absorption tower into which exhaust gas is introduced. Spray nozzles spray the electrolyzed alkaline water in the exhaust gas absorption tower.